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Background: Adjuvant chemotherapy offers survival benefit to patients with gastric cancer. Only 50-65% of patients who undergo neoadjuvant chemotherapy and gastrectomy are able to receive adjuvant therapy. It is optimal to start adjuvant therapy within 8 weeks after gastrectomy. We compared the rate of return to intended oncologic therapy (RIOT) between minimally invasive gastrectomy (MIG) and open gastrectomy (OG)., Method: Retrospectively, we analyzed patients who underwent gastrectomy within a multi-hospital university-based health system (2019-2022). Data on patient demographics, comorbid conditions, operative approach, and postoperative outcomes were assessed with univariate analysis and multivariable analysis (MVA) to determine the association with RIOT., Results: Among 87 eligible patients, 33 underwent MIG and 54 underwent OG. There were no differences in demographics, performance status, comorbid conditions, or type of gastrectomy between the two groups. MIG patients were significantly more likely to RIOT compared with OG patients (87.9% vs. 63%, p = 0.003), with 73.1% of MIG patients starting adjuvant therapy within 8 weeks compared with 53.1% of OG patients. Factors associated with higher odds of RIOT included MIG and age <65 years, while major postoperative complications (Clavien-Dindo grade ≥IIIa) was associated with lower odds of RIOT. On MVA, MIG was independently associated with higher odds of RIOT compared with OG (odds ratio 6.05, 95% confidence interval 1.47-24.78, p = 0.008)., Conclusion: The minimally invasive approach may benefit patients undergoing gastrectomy, irrespective of the extent of gastric resection for adenocarcinoma. MIG is associated with a higher likelihood of (1) RIOT and (2) starting adjuvant therapy within the optimal time period after gastrectomy., Competing Interests: Disclosures: Mihir M. Shah is a Proctor with Intuitive Inc., for robotic surgery. Andee Koo, Parit T. Mavani, Caitlin Sok, Subir Goyal, Seth Concors, Meredith C. Mason, Joshua H. Winer, Maria C. Russell, Kenneth Cardona, Edward Lin, Shishir K. Maithel, David A. Kooby, and Charles A. Staley III have no conflicts of interest to declare that may be relevant to the contents of this study., (© 2024. Society of Surgical Oncology.)

Background: Incisional hernia (IH) results in significant morbidity to patients and financial burden to healthcare systems. We aimed to determine the incidence of IH in distal pancreatectomy (DP) patients, stratified by specimen extraction sites., Method: Imaging in DP patients in our institution from 2016 to 2021 were reviewed by radiologists blinded to the operative approach. Specimen extraction sites were stratified as upper midline/umbilical (UM) versus Pfannenstiel. IH was defined as fascial defect on postoperative imaging. Patients without preoperative and postoperative imaging were excluded., Results: Of the 219 patients who met our selection criteria, the median age was 64 years, 54% were female, and 64% were White. The majority were minimally invasive (MIS) procedures (n = 131, 60%), of which 52% (n = 64) had a UM incision for specimen extraction, including 45 hand-assist and 19 purely laparoscopic procedures. MIS with Pfannenstiel incisions for specimen extraction was 48% (n = 58), including 44 robotic and 14 purely laparoscopic procedures. Mean follow-up time was 16.3 months (standard deviation [SD] 20.8). Follow-up for MIS procedures with UM incisions was 16.6 months (SD 21.8) versus 15.5 months (SD 18.6) in the Pfannenstiel group (p = 0.30). MIS procedures with UM incisions for specimen extraction had a 17.8 times increase in odds of developing an IH compared with MIS procedures with Pfannenstiel extraction sites (p = 0.01). The overall odds of developing an IH increased by 4% for every month of follow-up (odds ratio 1.04; p < 0.001)., Conclusion: A Pfannenstiel incision should be performed for specimen extraction in cases with purely laparoscopic or robotic distal pancreatectomy, when feasible., (© 2024. Society of Surgical Oncology.)

Competing Interests: Disclosure. Dr. Shah is a Proctor with Intuitive Inc. for Robotic Surgery

Objective: Postoperative pancreatic fistula is a potentially devastating complication after pancreatoduodenectomy (PD). The purpose of this study was to identify features on preoperative computed tomography (CT) imaging that correlate with an increased risk of postoperative pancreatic fistula (POPF)., Methods: Patients who underwent PD at our high-volume pancreatic surgery center from 2019 to 2021 were included if CT imaging was available within 8 weeks of surgical intervention. Pancreatic neck thickness (PNT), abdominal wall thickness (AWT), and intra-abdominal distance from pancreas to peritoneum (PTP) were measured by two board-certified radiologists who were blinded to the clinical outcomes. Radiographic measurements, as well as preoperative patient characteristics and intraoperative data, were assessed with univariate and multivariable analysis (MVA) to determine risk for clinically relevant POPF (CR-POPF, grades B and C)., Results: A total of 204 patients met inclusion criteria. Median PTP was 5.8 cm, AWT 1.9 cm, and PNT 1.3 cm. CR-POPF occurred in 33 of 204 (16.2%) patients. MVA revealed PTP > 5.8 cm (odds ratio [OR] 2.86, p = 0.023), PNT > 1.3 cm (OR 2.43, p = 0.047), soft pancreas consistency (OR 3.47, p = 0.012), and pancreatic duct size ≤ 3.0 mm (OR 4.55, p = 0.01) as independent risk factors for CR-POPF after PD. AWT and obesity were not associated with increased risk of CR-POPF. Patients with PTP > 5.8 cm or PNT > 1.3 cm were significantly more likely to suffer a major complication after PD (39.6% vs. 22.3% and 40% vs. 22.1%, p < 0.008)., Conclusions: Patients with a thick pancreatic neck and increased intra-abdominal girth have a heightened risk of CR-POPF after pancreatoduodenectomy, and they experience more serious postoperative complications. We defined a simple CT scan-based measurement tool to identify patients at increased risk of CR-POPF., (© 2023. Society of Surgical Oncology.)

Background: Surgery is the mainstay of treatment for retroperitoneal sarcoma (RPS), but local recurrence is common. Biologic behavior and recurrence patterns differ significantly among histologic types of RPS, with implications for management. The Transatlantic Australasian RPS Working Group (TARPSWG) published a consensus approach to primary RPS, and to complement this, one for recurrent RPS in 2016. Since then, additional studies have been published, and collaborative discussion is ongoing to address the clinical challenges of local recurrence in RPS., Methods: An extensive literature search was performed, and the previous consensus statements for recurrent RPS were updated after review by TARPSWG members. The search included the most common RPS histologic types: liposarcoma, leiomyosarcoma, solitary fibrous tumor, undifferentiated pleomorphic sarcoma, and malignant peripheral nerve sheath tumor., Results: Recurrent RPS management was evaluated from diagnosis to follow-up evaluation. For appropriately selected patients, resection is safe. Nomograms currently are available to help predict outcome after resection. These and other new findings have been combined with expert recommendations to provide 36 statements, each of which is attributed a level of evidence and grade of recommendation. In this updated document, more emphasis is placed on histologic type and clarification of the intent for surgical treatment, either curative or palliative. Overall, the fundamental tenet of optimal care for patients with recurrent RPS remains individualized treatment after multidisciplinary discussion by an experienced team with expertise in RPS., Conclusions: Updated consensus recommendations are provided to help guide decision-making for treatment of locally recurrent RPS and better selection of patients who would potentially benefit from surgery., (© 2022. Society of Surgical Oncology.)

Background: Prognostic nomograms for patients with resected extremity soft tissue sarcoma (STS) include the Sarculator and Memorial Sloan Kettering (MSKCC) nomograms. We sought to validate these two nomograms within a large, modern, multi-institutional cohort of resected primary extremity STS patients., Methods: Resected primary extremity STS patients from 2000 to 2017 were identified across nine high-volume U.S. institutions. Predicted 5- and 10-year overall survival (OS) and distant metastases cumulative incidence (DMCI), and 4-, 8-, and 12-year disease-specific survival (DSS) were calculated with Sarculator and MSKCC nomograms, respectively. Predicted survival probabilities stratified in quintiles were compared in calibration plots to observed survival assessed by Kaplan-Meier estimates. Cumulative incidence was estimated for DMCI. Harrell's concordance index (C-index) assessed discriminative ability of nomograms., Results: A total of 1326 patients underwent resection of primary extremity STS. Common histologies included: undifferentiated pleomorphic sarcoma (35%), fibrosarcoma (13%), and leiomyosarcoma (9%). Median tumor size was 8.0 cm (IQR 4.5-13.0). Tumor grade distribution was: Grade 1 (13%), Grade 2 (9%), Grade 3 (78%). Median OS was 172 months, with estimated 5- and 10-year OS of 70% and 58%. C-indices for 5- and 10-year OS (Sarculator) were 0.72 (95% CI 0.70-0.75) and 0.73 (95% CI 0.70-0.75), and 0.72 (95% CI 0.69-0.75) for 5- and 10-year DMCI. C-indices for 4-, 8-, and 12-year DSS (MSKCC) were 0.71 (95% CI 0.68-0.75). Calibration plots showed good prognostication across all outcomes., Conclusions: Sarculator and MSKCC nomograms demonstrated good prognostic ability for survival and recurrence outcomes in a modern, multi-institutional validation cohort of resected primary extremity STS patients. External validation of these nomograms supports their ongoing incorporation into clinical practice., (© 2022. Society of Surgical Oncology.)

Background: Local recurrence following resection of retroperitoneal liposarcoma (RLPS) is common. Well-differentiated (WD) and dedifferentiated (DD) RLPS are distinct entities with differing outcomes. A few reports suggest that WDLPS can recur as DDLPS and that DDLPS can recur as WDLPS. This study evaluates whether this change in differentiation from the primary tumor to the first local recurrence impacts long-term outcomes., Methods: Retrospective review from 22 sarcoma centers identified consecutive patients who underwent resection for a first locally recurrent RLPS from January 2002 to December 2011. Outcomes measured included overall survival, local recurrence, and distant metastasis., Results: A total of 421 RPLS patients were identified. Of the 230 patients with primary DDLPS, 34 (15%) presented WDLPS upon recurrence (DD → WD); and of the 191 patients with primary WDLPS, 54 (28%) presented DDLPS upon recurrence (WD → DD). The 6-year overall survival probabilities (95% CI) for DD → DD, DD → WD, WD → WD, and WD → DD were 40% (32-48%), 73% (58-92%), 76% (68-85%), and 56% (43-73%) (p < 0.001), respectively. The 6-year second local recurrence incidence was 66% (59-73%), 63% (48-82%), 66% (57-76%), and 77% (66-90%), respectively. The 6-year distant metastasis incidence was 13% (9-19%), 3% (0.4-22%), 5% (2-11%), and 4% (1-16%), respectively. On multivariable analysis, DD → WD was associated with improved overall survival when compared with DD → DD (p < 0.001). Moreover, WD → DD was associated with a higher risk of LR (p = 0.025) CONCLUSION: A change in RLPS differentiation from primary tumor to first local recurrence appears to impact survival. These findings may be useful in counseling patients on their prognosis and subsequent management., (© 2021. Society of Surgical Oncology.)

Background: Retroperitoneal soft tissue sarcomas comprise a heterogeneous group of rare tumors of mesenchymal origin that include several well-defined histologic subtypes. In 2015, the Transatlantic Australasian RPS Working Group (TARPSWG) published consensus recommendations for the best management of primary retroperitoneal sarcoma (RPS). Since then, through international collaboration, new evidence and knowledge have been generated, creating the need for an updated consensus document., Methods: The primary aim of this study was to critically evaluate the current evidence and develop an up-to-date consensus document on the approach to these difficult tumors. The resulting document applies to primary RPS that is non-visceral in origin, with exclusion criteria as previously described. The relevant literature was evaluated and an international group of experts consulted to formulate consensus statements regarding the best management of primary RPS. A level of evidence and grade of recommendation were attributed to each new/updated recommendation., Results: Management of primary RPS was considered from diagnosis to follow-up. This rare and complex malignancy is best managed by an experienced multidisciplinary team in a specialized referral center. The best chance of cure is at the time of primary presentation, and an individualized management plan should be made based on the 29 consensus statements included in this article, which were agreed upon by all of the authors. Whenever possible, patients should be enrolled in prospective trials and studies., Conclusions: Ongoing international collaboration is critical to expand upon current knowledge and further improve outcomes of patients with RPS. In addition, prospective data collection and participation in multi-institution trials are strongly encouraged., (© 2021. Society of Surgical Oncology.)

Background: Multi-visceral resection often is used in the treatment of retroperitoneal sarcoma (RPS). The morbidity after distal pancreatectomy for primary pancreatic cancer is well-documented, but the outcomes after distal pancreatectomy for primary RPS are not. This study aimed to evaluate morbidity and oncologic outcomes after distal pancreatectomy for primary RPS., Methods: In this study, 26 sarcoma centers that are members of the Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) retrospectively identified consecutive patients who underwent distal pancreatectomy for primary RPS from 2008 to 2017. The outcomes measured were 90-day severe complications (Clavien-Dindo ≥ 3), postoperative pancreatic fistula (POPF) rate, and oncologic outcomes., Results: Between 2008 and 2017, 280 patients underwent distal pancreatectomy for primary RPS. The median tumor size was 25 cm, and the median number of organs resected, including the pancreas, was three. In 96% of the operations, R0/R1 resection was achieved. The 90-day severe complication rate was 40 %. The grades B and C POPF complication rates were respectively 19% and 5% and not associated with worse overall survival. Administration of preoperative radiation and factors to mitigate POPF did not have an impact on the risk for the development of a POPF. The RPS invaded the pancreas in 38% of the patients, and local recurrence was doubled for the patients who had a microscopic, positive pancreas margin (hazard ratio, 2.0; p = 0.042)., Conclusion: Distal pancreatectomy for primary RPS has acceptable morbidity and oncologic outcomes and is a reasonable approach to facilitate complete tumor resection., (© 2021. Society of Surgical Oncology.)

Background: This study aimed to evaluate perioperative morbidity after surgery for first locally recurrent (LR1) retroperitoneal sarcoma (RPS). Data concerning the safety of resecting recurrent RPS are lacking., Methods: Data were collected on all patients undergoing resection of RPS-LR1 at 22 Trans-Atlantic Australasian Retroperitoneal Sarcoma Working Group (TARPSWG) centers from 2002 to 2011. Uni- and multivariable logistic models were fitted to study the association between major (Clavien-Dindo grade ≥ 3) complications and patient/surgery characteristics as well as outcome. The resected organ score, a method of standardizing the number of organs resected, as previously described by the TARPSWG, was used., Results: The 681 patients in this study had a median age of 59 years, and 51.8% were female. The most common histologic subtype was de-differentiated liposarcoma (43%), the median resected organ score was 1, and 83.3% of the patients achieved an R0 or R1 resection. Major complications occurred for 16% of the patients, and the 90-day mortality rate was 0.4%. In the multivariable analysis, a transfusion requirement was found to be a significant predictor of major complications (p < 0.001) and worse overall survival (OS) (p = 0.010). However, having a major complication was not associated with a worse OS or a higher incidence of local recurrence or distant metastasis., Conclusions: A surgical approach to recurrent RPS is relatively safe and comparable with primary RPS in terms of complications and postoperative mortality when performed at specialized sarcoma centers. Because alternative effective therapies still are lacking, when indicated, resection of a recurrent RPS is a reasonable option. Every effort should be made to minimize the need for blood transfusions.

Background: Nephrectomy often is required during en bloc resection of a retroperitoneal sarcoma (RPS) to achieve an R0 or R1 resection. The impact of nephrectomy on postoperative renal function in this patient population, who also may benefit from subsequent nephrotoxic systemic therapy, is not well described., Methods: The United States Sarcoma Collaborative (USSC) database was queried for patients undergoing RPS resection between 2000 and 2016. Patients with missing pre- or postoperative measures of renal function were excluded. A matched cohort was created using coarsened exact matching. Weighted logistic regression was used to control further for differences between the nephrectomy and non-nephrectomy cohorts. The primary outcomes were postoperative acute kidney injury (AKI), acute renal failure (ARF), and dialysis., Results: The initial cohort consisted of 858 patients, 3 (0.3%) of whom required postoperative dialysis. The matched cohort consisted of 411 patients, 108 (26%) of whom underwent nephrectomy. The patients who underwent nephrectomy had higher rates of postoperative AKI (14.8% vs 4.3%; p < 0.01) and ARF (4.6% vs 1.3%; p = 0.04), but no patients required dialysis postoperatively. Logistic regression modeling showed that the risk of AKI (odds ratio [OR], 5.16; p < 0.01) and ARF (OR 5.04; p < 0.01) after nephrectomy persisted despite controlling for age and preoperative renal function., Conclusions: Nephrectomy is associated with an increased risk of postoperative AKI and ARF after RPS resection. This study was unable to statistically assess the impact of nephrectomy on postoperative dialysis, but the risk of postoperative dialysis is 0.5% or less regardless of nephrectomy status.

Background: Pancreatoduodenectomy (PD) for duodenal adenoma (DA) resection may be associated with excessive surgical risk for patients with potentially benign lesions, given the absence of pancreatic duct obstruction. We examined factors associated with final malignant pathology and evaluated the postoperative course of patients with DA versus pancreatic ductal adenocarcinoma (PDAC)., Methods: We retrospectively analyzed patients with DA who underwent PD from 2008 to 2018 and assessed the accuracy rate of preoperative biopsy and factors associated with final malignant pathology. Complications for DA patients were compared with those of matched PDAC patients., Results: Forty-five consecutive patients who underwent PD for DA were identified, and the preoperative biopsy false negative rate was 29. Factors associated with final malignant pathology included age over 70 years, preoperative biliary obstruction, and common bile duct diameter > 8 mm (p < 0.05). Compared with patients with PDAC (n = 302), DA patients experienced more major complications (31% vs. 15%, p < 0.01), more grade C postoperative pancreatic fistulas (9% vs. 1%, p < 0.01), and greater mortality (7% vs. 2%, p < 0.05). Propensity score matched patients with DA had more major complications following PD (32% vs. 12%, p < 0.05)., Conclusions: Preoperative biopsy of duodenal adenomas is associated with a high false-negative rate for malignancy, and PD for DA is associated with higher complication rates than PD for PDAC. These results aid discussion among patients and surgeons who are considering observation versus PD for DA, especially in younger patients without biliary obstruction, who are less likely to harbor malignancy.

Background: Surgery alone is standard-of-care for stage I gastric adenocarcinoma; however, clinicians can offer preoperative therapy for clinical stage I disease with signet ring cell histology, given its presumed aggressive biology. We aimed to assess the validity of this practice., Methods: The National Cancer Database (2004-2015) was reviewed for patients with clinical stage I signet ring cell gastric adenocarcinoma who underwent treatment with surgery alone, perioperative chemotherapy, neoadjuvant therapy, or adjuvant therapy. Analysis was stratified by preoperative clinical/pathologic stage. Primary outcome was overall survival (OS)., Results: Of 1018 patients, median age was 60 years (±14); 53% received surgery alone (n = 542), 5% received perioperative chemotherapy (n = 47), 12% received neoadjuvant therapy (n = 125), and 30% received adjuvant therapy (n = 304). For clinical stage I disease, surgery alone was associated with an improved 5-year OS rate (71%) versus perioperative chemotherapy (58%), neoadjuvant therapy (38%), or adjuvant therapy (52%) [overall p < 0.01]. For pathologic stage I, surgery alone had equivalent or improved survival compared with perioperative, neoadjuvant, and adjuvant therapy (5-year OS: 78% vs. 89% [p = 0.77] vs. 64% [p = 0.04] vs. 84% [p = 0.99]). Adjuvant therapy was associated with improved 5-year OS compared with pretreatment for those patients upstaged (37%) to pathologic stage II/III (55% vs. 36% and 34% vs. 7%; all p < 0.01)., Conclusions: This stage-specific study demonstrates improved survival with surgery alone for clinical stage I signet ring cell gastric adenocarcinoma. Despite 37% of clinical stage I patients being upstaged to pathologic stage II/III, adjuvant therapy offers a favorable rescue strategy, with improved outcomes compared with those treated preoperatively. Surgery alone also affords similar or improved survival for pathologic stage I disease versus multimodality therapy. This study challenges the bias to overtreat stage I signet ring cell gastric adenocarcinoma.

Objective: The aim of this study was to determine the association between lymphovascular invasion (LVI) and overall survival (OS) in truncal/extremity soft tissue sarcomas (STS)., Methods: The National Cancer Database (NCDB) was queried for all patients, ages 18-85 years, who underwent resection of primary, truncal/extremity STS between 2010 and 2012, and had LVI data. The primary endpoint was OS., Results: Among 6169 patients identified, the most common histology groups were (1) liposarcoma (LPS, 24%), (2) undifferentiated pleiomorphic sarcoma (UPS, 19%), and (3) leiomyosarcoma (LMS, 15%); 449 patients (7%) were LVI-positive. There were no differences in demographics or comorbidities between the LVI groups. Compared with LVI-negative patients, LVI-positive patients were more likely to have larger (> 5 cm: 80% vs. 66%), deep (80% vs. 68%), and high-grade tumors (82% vs. 57%). They were also more likely to have positive margins (27% vs. 17%), nodal (16% vs. 2%) and metastatic disease (21% vs. 4%), and receive chemotherapy (37% vs. 18%; all p < 0.001). LVI was associated with worse median OS (39 months vs. MNR; p < 0.001), which persisted on stratum-specific analyses for all tumor grades, size categories, and stages I-III, but not stage IV. On multivariable Cox regression, LVI was associated with worse OS (hazard ratio [HR] 1.84, 95% confidence interval [CI] 1.39-2.44), while accounting for other significant prognostic factors. Among non-metastatic, curative-intent resections (n = 5696), LVI was still associated with worse OS (HR 1.79, 95% CI 1.28-2.49)., Conclusions: LVI appears to be an important adverse pathologic factor in truncal and extremity STS. Even when taking into account other established prognostic factors, LVI was predictive of worse OS. Knowledge of LVI status may help to better risk-stratify patients and guide management strategies, and should be considered in future prognostic classification schemes and nomograms.

Background: The role of neoadjuvant chemotherapy (NCT) for high-risk soft tissue sarcoma (STS) is questioned. This study aimed to define which patients may experience a survival advantage with NCT., Methods: All the patients from the U.S. Sarcoma Collaborative database (2000-2016) who underwent curative-intent resection of high-grade, primary truncal/extremity STS size 5 cm or larger were included in this study. The primary end points were recurrence-free survival (RFS) and overall survival (OS)., Results: Of the 4153 patients, 770 were included in the study. The median tumor size was 10 cm, and 669 of the patients (87%) had extremity tumors. The most common histology was undifferentiated pleomorphic sarcoma (UPS), found in 42% of the patients. Of the 770 patients, 216 (28%) received NCT. The patients who received NCT had deeper, larger tumors (p < 0.001). Of the patients with tumors 5 cm or larger and 8 cm or larger, NCT was not associated with improved RFS or OS. However for the patients with tumors 10 cm or larger, NCT was associated with improved 5-year RFS (51% vs 40%; p = 0.053) and 5-year OS (58% vs 47%; p = 0.043). By location, the patients with extremity tumors 10 cm or larger but not truncal tumors had improved 5-yearr RFS (54% vs 42%; p = 0.042) and 5-year OS (61% vs 47%; p = 0.015) with NCT. According to histology, no subtype had improved RFS or OS with NCT, although the patients with UPS had a trend toward improved 5-year RFS (56% vs 42%; p = 0.092) and 5-year OS (66% vs 52%; p = 0.103) with NCT., Conclusion: For the patients with high-grade STS, NCT was associated with improved RFS and OS when tumors were 10 cm or larger and located in the extremity. However, no histiotype-specific advantage was identified. Future studies assessing the efficacy of NCT may consider focusing on these patients, with added focus on histology-specific strategies.

Background: Preoperative factors that reliably predict lymph node (LN) metastases in pancreatic neuroendocrine tumors (PanNETs) are unclear. The number of LNs needed to accurately stage PanNETs has not been defined., Methods: Patients who underwent curative-intent resection of non-functional PanNETs at eight institutions from 2000 to 2016 were analyzed. Preoperative factors associated with LN metastases were identified. A procedure-specific target for LN retrieval to accurately stage patients was determined., Results: Of 695 patients who underwent resection, 33% of tumors were proximal (head/uncinate) and 67% were distal (neck/body/tail). Twenty-six percent of patients (n = 158) had LN-positive disease, which was associated with a worse 5-year recurrence-free survival (RFS; 60% vs. 86%; p < 0.001). The increasing number of positive LNs was not associated with worse RFS. Preoperative factors associated with positive LNs included tumor size ≥ 2 cm (odds ratio [OR] 6.6; p < 0.001), proximal location (OR 2.5; p < 0.001), moderate versus well-differentiation (OR 2.1; p = 0.006), and Ki-67 ≥ 3% (OR 3.1; p < 0.001). LN metastases were also present in tumors without these risk factors: < 2 cm (9%), distal location (19%), well-differentiated (23%), and Ki-67 < 3% (16%). Median LN retrieval was 13 for pancreatoduodenectomy (PD), but only 9 for distal pancreatectomy (DP). Given that PD routinely includes a complete regional lymphadenectomy, a minimum number of LNs to accurately stage patients was not identified. However, for DP, removal of less than seven LNs failed to discriminate 5-year RFS between LN-positive and LN-negative patients (less than seven LNs: 72% vs. 83%, p = 0.198; seven or more LNs: 67% vs. 86%; p = 0.002)., Conclusions: Tumor size ≥ 2 cm, proximal location, moderate differentiation, and Ki-67 ≥ 3% are preoperative factors that predict LN positivity in resected non-functional PanNETs. Given the 9-23% incidence of LN metastases in patients without such risk factors, routine regional lymphadenectomy should be considered. PD inherently includes sufficient LN retrieval, while DP should aim to remove seven or more LNs for accurate staging.

Background: The Ki-67 index is an established prognostic marker for recurrence after resection of pancreatic neuroendocrine tumors (PanNETs) that groups tumors into three categories: low grade (< 3%), intermediate grade (3-20%), and high grade (> 20%). Given that the majority of resected PanNETs have a Ki-67 less than 3%, this study aimed to stratify this group further to predict disease recurrence more accurately., Methods: The Ki-67 index was pathologically re-reviewed and scored by a pathologist blinded to all other clinicopathologic variables using tissue microarray blocks made in triplicate. All patients who underwent curative-intent resection of non-metastatic PanNETs at a single institution from 2000 to 2013 were included in the study. The primary outcome was recurrence-free survival (RFS)., Results: Of 113 patients with well-differentiated PanNETs resected, 83 had tissue available for pathologic re-review. The Ki-67 index was lower than 3% for 72 tumors (87%) and between 3 and 20% for 11 tumors (13%). Considering only Ki-67 less than 3%, the tumors were further stratified by Ki-67 into three groups: group A (< 1%, n = 43), group B (1-1.99%, n = 23), and group C (2-2.99%, n = 6). Compared with group A, groups B and C more frequently had advanced T stage (T3: 44% and 67% vs 12%; p = 0.003) and lymphovascular invasion (50% and 83% vs 23%; p = 0.007). Groups B and C had similar 1- and 3-year RFS, both less than group A. After combining groups B and C, a Ki-67 of 1-2.99% was associated with decreased RFS compared with group A (< 1%). This persisted in the multivariable analysis (hazard ratio [HR] 8.6; 95% confidence interval [CI] 1.0-70.7; p = 0.045), with control used for tumor size, margin-positivity, lymph node involvement, and advanced T stage., Conclusions: PanNETs with a Ki-67 of 1-2.99% exhibit distinct biologic behavior and earlier disease recurrence than those with a Ki-67 lower than 1%. This new stratification scheme, if externally validated, should be incorporated into future grading systems to guide both surveillance protocols and treatment strategies.

Introduction: Postoperative complications (POCs) negatively impact oncologic outcomes in some malignancies; however, little is known regarding their effect in soft tissue sarcoma (STS). The aim of this study was to determine the impact of POCs on survival after resection of truncal and extremity STS., Methods: All patients who underwent resection for a primary truncal or extremity STS at a single academic institution from 2000 to 2015 were included and analyzed. Primary outcome was disease-specific survival (DSS)., Results: Among 546 STS patients, POCs occurred in 159 (29%) patients; 57% were major and 55% were surgical site infections. Patients with POCs were older (61 vs. 53 years), had more comorbidities (50 vs. 38%), longer operative time (127 vs. 93 min), higher-grade tumors (93 vs. 86%), and were more likely to receive preoperative radiation (42 vs. 33%; all p < 0.05). There was no difference in receipt of postoperative therapy between the POCs and no POCs groups (19 vs. 18%, p = 0.74). Median follow-up for survivors was 37 months, and the 5-year DSS for the entire cohort was 78%. Compared with patients without POCs, patients with POCs had a worse DSS (68% vs. 81%, p = 0.001). Predictors for decreased DSS on univariate analysis included POCs (hazard ratio [HR] 2.12, 95% confidence interval [CI] 1.37-3.28, p = 0.001), advanced age, neurovascular/bone resection, positive margin, high grade, and preoperative and postoperative therapy (all p < 0.05). POCs (HR 1.76, 95% CI 1.08-2.87, p = 0.02) remained an independent predictor for reduced DSS on multivariate analysis, along with age (HR 1.02, p = 0.046) and tumor grade (HR 7.62, p = 0.046)., Conclusions: POCs following resection of truncal and extremity STS are associated with decreased DSS. Efforts to optimize modifiable risk factors and decrease the rate of POCs warrant further investigation.

Background: This study was designed to develop a more robust predictive model, beyond T-stage alone, for incidental gallbladder cancer (IGBC) for discovering locoregional residual (LRD) and distant disease (DD) at reoperation, and estimating overall survival (OS). T-stage alone is currently used to guide treatment for incidental gallbladder cancer. Residual disease at re-resection is the most important factor in predicting outcomes., Methods: All patients with IGBC who underwent reoperation at 10 institutions from 2000 to 2015 were included. Routine pathology data from initial cholecystectomy was utilized to create the gallbladder cancer predictive risk score (GBRS)., Results: Of 449 patients with gallbladder cancer, 262 (58 %) were incidentally discovered and underwent reoperation. Advanced T-stage, grade, and presence of lymphovascular (LVI) and perineural (PNI) invasion were all associated with increased rates of DD and LRD and decreased OS. Each pathologic characteristic was assigned a value (T1a: 0, T1b: 1, T2: 2, T3/4: 3; well-diff: 1, mod-diff: 2, poor-diff: 3; LVI-neg: 1, LVI-pos: 2; PNI-neg: 1, PNI-pos: 2), which added to a total GBRS score from 3 to 10. The scores were separated into three risk-groups (low: 3-4, intermediate: 5-7, high: 8-10). Each progressive GBRS group was associated with an increased incidence LRD and DD at the time of re-resection and reduced OS., Conclusions: By accounting for subtle pathologic variations within each T-stage, this novel predictive risk-score better stratifies patients with incidentally discovered gallbladder cancer. Compared with T-stage alone, it more accurately identifies patients at risk for locoregional-residual and distant disease and predicts long-term survival as it redistributes T1b, T2, and T3 disease across separate risk-groups based on additional biologic features. This score may help to optimize treatment strategy for patients with incidentally discovered gallbladder cancer.

Background: Use of adjuvant chemotherapy (CTx) and chemoradiation therapy (cXRT) for the treatment of gallbladder cancer (GBC) remains varied. We sought to define the utilization and effect of adjuvant therapy for patients with GBC., Methods: Using a multi-institutional national database, 291 patients with GBC who underwent curative-intent resection between 2000 and 2015 were included. Patients with metastasis or an R2 margin were excluded., Results: Median patient age was 66.6 years. Most patients had a T2 (46.2 %) or T3 (38.6 %) lesion, and 37.8 % of patients had lymph node (LN) metastasis. A total of 186 (63.9 %) patients underwent surgery alone, 61 (21.0 %) received CTx, and 44 (15.1 %) patients received cXRT. On multivariable analysis, factors associated with worse overall survival (OS) included T3/T4 stage [hazard ratio (HR) 1.82], LN-metastasis (HR 1.84), lymphovascular invasion (HR 2.02), perineural invasion (HR 1.42), and R1 surgical margin status (HR 2.06); all P < 0.05). In contrast, receipt of CTx/cXRT was associated with improved OS (CTx, HR 0.38; cXRT, HR 0.26; P < 0.001) compared with surgery alone. Similar results were observed for disease-free survival (DFS) (CTx, HR 0.61; cXRT, HR 0.43; P < 0.05). Of note, only patients with high-risk features, such as AJCC T3/T4 stage (HR 0.41), LN metastasis (HR 0.45), and R1 disease (HR 0.21) (all P < 0.05) derived an OS benefit from CTx/cXRT., Conclusions: Adjuvant CTx/cXRT was utilized in 36 % of patients undergoing curative-intent resection for GBC. After adjusted analyses, CTx/cXRT were independently associated with improved long-term outcomes, but the benefit was isolated to only patients with high-risk characteristics.

Background: Postoperative complications (POCs) can negatively impact survival after oncologic resection. POCs may also decrease the rate of adjuvant therapy completion. We evaluated the impact of complications on gastric cancer survival and analyzed the combined effect of complications and adjuvant therapy on survival., Methods: We analyzed 824 patients from 7 institutions of the U.S. Gastric Cancer Collaborative who underwent curative resection for gastric adenocarcinoma between 2000 and 2012. POC were graded using the modified Clavien-Dindo system. Survival probabilities were estimated using the method of Kaplan and Meier and analyzed using multivariate Cox regression., Results: Median follow-up was 35 months. The overall complication rate was 41 %. The 5-year overall survival (OS) and recurrence-free survival (RFS) of patients who experienced complications were 27 and 23 %, respectively, compared with 43 and 40 % in patients who did not have complications (p < 0.0001 for OS and RFS). On multivariate analysis, POC remained an independent predictor for decreased OS and RFS (HR 1.3, 95 % CI 1.1-1.6, p = 0.03 for OS; HR 1.3, 95 % CI 1.01-1.6, p = 0.03 for RFS). Patients who experienced POC were less likely to receive adjuvant therapy (OR 0.5, 95 % CI 0.3-0.7, p < 0.001). The interaction of complications and failure to receive adjuvant therapy significantly increased the hazard of death compared with patients who had neither complications nor adjuvant therapy (HR 2.3, 95 % CI 1.6-3.2, p < 0.001)., Conclusions: Postoperative complications adversely affect long-term outcomes after gastrectomy for gastric cancer. Not receiving adjuvant therapy in the face of POC portends an especially poor prognosis following gastrectomy for gastric cancer.

Background: Limited data exist on the prognosis of preoperative Helicobacter pylori (H. pylori) infection in gastric adenocarcinoma (GAC)., Methods: Patients who underwent curative-intent resection for GAC from 2000 to 2012 at seven academic institutions comprising the United States Gastric Cancer Collaborative were included in the study. The primary end points of the study were overall survival (OS), recurrence-free survival (RFS), and disease-specific survival (DSS)., Results: Of 559 patients, 104 (18.6 %) who tested positive for H. pylori were younger (62.1 vs 65.1 years; p = 0.041), had a higher frequency of distal tumors (82.7 vs 71.9 %; p = 0.033), and had higher rates of adjuvant radiation therapy (47.0 vs 34.9 %; p = 0.032). There were no differences in American Society of Anesthesiology (ASA) class, margin status, grade, perineural invasion, lymphovascular invasion, nodal metastases, or tumor-node-metastasis (TNM) stage. H. pylori positivity was associated with longer OS (84.3 vs 44.2 months; p = 0.008) for all patients. This relationship with OS persisted in the multivariable analysis (HR 0.54; 95 % CI 0.30-0.99; p = 0.046). H. pylori was not associated with RFS or DSS in all patients. In the stage 3 patients, H. pylori was associated with longer OS (44.5 vs 24.7 months; p = 0.018), a trend of longer RFS (31.4 vs 21.6 months; p = 0.232), and longer DSS (44.8 vs 27.2 months; p = 0.034)., Conclusions: Patients with and without preoperative H. pylori infection had few differences in adverse pathologic features at the time of gastric adenocarcinoma resection. Despite similar disease presentations, preoperative H. pylori infection was independently associated with improved OS. Further studies examining the interaction between H. pylori and tumor immunology and genetics are merited.

Background: The effect of routine drainage after abdominal surgery with enteric anastomoses is controversial. In particular, the role of peritoneal drain (PD) placement after total gastrectomy for adenocarcinoma is not well established., Methods: Patients who underwent total gastrectomy for gastric adenocarcinoma (GAC) at seven institutions from the US Gastric Cancer Collaborative, from 2000 to 2012, were identified. The association of PD placement with postoperative outcomes was analyzed., Results: Overall, 344 patients were identified and 253 (74 %) patients received a PD. The anastomotic leak rate was 9 %. Those with PD placement had similar American Society of Anesthesiologists score, tumor size, TNM stage, and the need for additional organ resection when compared with their counterparts. No difference was observed in the rate of any complication (54 vs. 48 %; p = 0.45), major complication (25 vs. 24 %; p = 0.90), or 30-day mortality (7 vs. 4 %; p = 0.51) between the two groups. In addition, no difference in anastomotic leak (9 vs. 10 %; p = 0.90), the need for secondary drainage (10 vs. 9 %; p = 0.92), or reoperation (13 vs. 8 %; p = 0.28) was identified. On multivariate analysis, PD placement was not associated with decreased postoperative complications. Subset analysis, stratified by patients who did not undergo concomitant pancreatectomy (n = 319) or those who experienced anastomotic leak (n = 31), similarly demonstrated no association of PD placement with reduced complications or mortality., Conclusions: PD placement after total gastrectomy for GAC is associated with neither a decrease in the frequency and severity of adverse postoperative outcomes, including anastomotic leak and mortality, nor a decrease in the need for secondary drainage procedures or reoperation. Routine use of PDs is not warranted.

Background: Conflicting data exist on the prognostic implication of signet-ring cell (SRC) histology in gastric adenocarcinoma (GAC)., Methods: All patients who underwent curative-intent resection of GAC from the seven institutions of the U.S. Gastric Cancer Collaborative between 2000 and 2012 were included. Primary end points were recurrence-free survival (RFS) and overall survival (OS). Stage-specific analyses were performed., Results: A total of 768 patients met the inclusion criteria. SRC was present in 40.6 % of patients and was associated with female sex (52.9 vs. 38.6 %; p < 0.001), younger age (61 vs. 67 years; p < 0.001), poor differentiation (94.8 vs. 50.3 %; p < 0.001), perineural invasion (PNI) (41.4 vs. 23 %; p < 0.001), microscopically positive resection margins (R1, 24.7 vs. 8.6 %; p < 0.001), distal location (82.2 vs. 70.1 %; p < 0.001), receipt of adjuvant therapy (63 vs. 51.2 %; p = 0.002), and more advanced stage (stage 3: 55.2 vs. 36.5 %; p < 0.001). SRC was associated with earlier recurrence (56.7 months vs. median not reached; p = 0.009) and decreased OS (33.7 vs. 46.6 months; p = 0.011). When accounting for other adverse pathologic features, PNI (hazard ratio [HR] 1.57; p = 0.016) and higher stage (HR 2.64; p < 0.001) were associated with decreased RFS, but SRC was not. Although PNI (HR 1.52; p = 0.007), higher stage (HR 2.11; p < 0.001), greater size (HR 1.05; p = 0.016), and adjuvant therapy (HR 0.50; p < 0.001) were associated with OS, SRC was not. Similarly, when accounting for adverse pathologic factors on multivariate analysis, stage-specific analyses showed no association between SRC and RFS or OS., Conclusions: SRC histology is associated with adverse pathologic features including poor differentiation, higher stage, and microscopically positive resection margins but is not independently associated with reduced RFS or OS. Identification of signet-ring histology during preoperative evaluation should not, in isolation, dictate treatment strategy.

Background: Clinicians may order Octreoscan or positron emission tomography (PET) scan for staging patients with neuroendocrine tumors (NETs). (111)In-Octreoscan (Octreoscan) identifies tumors by radiolabeled targeting of somatostatin receptors, while 18F-fluorodeoxyglucose-positron emission tomography ((18)FDG-PET) measures differential tissue glucose transport. We assessed the sensitivity of both nuclear imaging modalities with pathologic correlation to define the best initial choice for NET staging after standard cross-sectional imaging., Methods: We identified all patients diagnosed with NETs of gastrointestinal or pancreatic origin who underwent nuclear imaging staging by Octreoscan and/or PET from 2000 to 2013. Imaging results were correlated with tumor differentiation and grade of pathology specimens., Results: Imaging and pathology results were identified for 153 patients. Of these, 131 underwent Octreoscan, 43 underwent PET, and 21 patients had both performed. Overall sensitivity of Octreoscan and PET for NET detection was similar (77 vs. 72 %; p = not significant). For well-differentiated NETs, Octreoscan (n = 124) demonstrated sensitivity of 80 vs. 60 % (p = 0.28) for PET (n = 30). For poorly-differentiated NETs, Octreoscan (n = 7) proved significantly less sensitive than PET (n = 13) (57 vs. 100 %; p = 0.02). The sensitivity of Octreoscan versus PET varied similarly when analyzed by WHO tumor grade: Grade 1 (79 vs. 52 %; p = 0.16), Grade 2 (85 vs. 86 %; p = not significant), and Grade 3 (57 vs. 100 %; p = 0.02)., Conclusions: Tumor differentiation can be used to guide selection of nuclear imaging modalities for staging gastrointestinal and pancreatic NETs. Octreoscan appears more sensitive than (18)FDG-PET for well-differentiated NETs, whereas (18)FDG-PET demonstrates superior sensitivity for poorly-differentiated NETs.

Background: The proximal gastric margin dictates the extent of resection for gastric adenocarcinoma (GAC). The value of achieving negative margins via additional gastric resection after a positive proximal margin frozen section (FS) is unknown., Methods: The US Gastric Cancer Collaborative includes all patients who underwent resection of GAC at seven institutions from 2000-2012. Intraoperative proximal margin FS data and final permanent section (PS) data were classified as R0 or R1, respectively; positive distal margins were excluded. The primary aim was to evaluate the impact on local recurrence of converting a positive proximal FS-R1 margin to a PS-R0 final margin by additional resection. Secondary endpoints were recurrence-free survival (RFS) and overall survival (OS)., Results: Of 860 patients, 520 had a proximal margin FS and 67 were positive. Of these, 48 were converted to R0 on PS by additional resection. R0 proximal margin was achieved in 447 patients (86 %), PS-R1 in 25 (5 %), and converted FS-R1-to-PS-R0 in 48 (9 %). The median follow-up was 44 months. Local recurrence was significantly decreased in the converted FS-R1-to-PS-R0 group compared to the PS-R1 group (10 vs. 32 %; p = 0.01). Median RFS was similar between the FS-R1-to-PS-R0 and PS-R1 cohorts (25 vs. 20 months; p = 0.49), compared to 37 months for the PS-R0 group. Median OS was similar between the FS-R1-to-PS-R0 conversion and PS-R1 groups (36 vs. 26 months; p = 0.14) compared to 50 months for the PS-R0 group. On multivariate analysis, increasing T-stage and N-stage were associated with worse OS; the FS-R1-to-PS-R0 proximal margin conversion was not significantly associated with improved RFS (p = 0.68) or OS (p = 0.44)., Conclusion: Conversion of a positive intraoperative proximal margin frozen section during gastric cancer resection may decrease local recurrence, but it is not associated with improved RFS or OS. This may guide decisions regarding the extent of resection.

Background: Two-stage hepatectomy (TSH) has been adopted as a treatment modality for resection of advanced colorectal liver metastases (CRLM). This study analyzed the recurrence pattern, salvage rate, and survival after TSH combined with systemic and regional chemotherapy., Methods: A retrospective review of a prospective database identified patients who underwent a TSH for CRLM was performed and outcome data analyzed., Results: From September 2000 to May 2009, a total of 40 patients were eligible for TSH, and 88 % completed both resections. Of the 35 resected patients, the median number of tumors was 8, with 38 % having a tumor >5 cm and 35 % having a carcinoembryonic antigen value >200 ng/ml. All patients received systemic chemotherapy, and 86 % received regional therapy with hepatic artery infusion. Median follow-up for survivors was 40 months; median disease-specific survival was 52 months, and 5-year disease-specific survival was 49 %. The combined rate of major complication for all procedures was 45 % with no operative deaths. Median recurrence-free survival was 11 months with a 3-year probability of recurrence of 81 %. Disease recurrence occurred in 27 patients (77 %), with the liver (42 %) and lung (37 %) being the most common sites. Sixteen of these patients (60 %) underwent salvage therapy via either surgery and/or ablation, 7 (44 %) of whom were free of disease at a median follow-up of 54 months., Conclusions: TSH combined with systemic and hepatic artery infusion chemotherapy is an effective treatment strategy for selected patients with advanced CRLM. These patients are at considerable risk of local and distant recurrence; however, the majority can be salvaged, and long-term survival can be achieved.

Background: Analysis of portal lymph node (LN) metastases following resection of biliary carcinomas at or above the cystic duct (BC) is used to select patients for adjuvant therapy, but no guidelines exist and LN yield is low. Some consider analysis of 7 LNs necessary for accurate staging. Conventional LN analysis may understage patients., Methods: Portal LNs from 38 node-negative patients following resection of BC from 2000 to 2008 were re-examined in detail for occult metastases (OM) using a modified Weaver protocol. Outcomes measured were discordance in LN positivity and patient survival., Results: On detailed examination, 5 of 38 patients had OM. There was no difference in survival between patients with and without OM (24 vs 17 months; p = .382). There was no association between OM and patient demographics or adverse tumor characteristics. The median LN yield was 3. Of the 27 patients with <7 LNs retrieved, 1 had OM, compared with 4 of 11 patients with ≥7 LNs retrieved (p = .030). OM in these well-staged patients were associated with reduced survival (9 vs 41 months; p = .032)., Conclusions: There is discordance between conventional and detailed LN analysis in resected BC. LN yield ≥7 was associated with OM. The presence of OM may be associated with decreased survival. Conventional LN analysis may understage patients with resected BC.

Background: Residual disease after pancreaticoduodenectomy (PD) for pancreatic adenocarcinoma (PDAC) adversely impacts survival. The value of taking additional neck margin after a positive frozen section (FS) to achieve a negative margin remains uncertain., Methods: All patients who underwent PD for PDAC from January 2000 August 2012 were identified and classified as negative (R0) or positive (R1) based on final neck margin. We examined factors for association with a positive FS neck margin and overall survival (OS). We assessed the value of converting an R1 neck margin to R0 via additional parenchymal resection., Results: A total of 382 patients had FS neck margin analysis, of which 53 (14 %) were positive. Positive FS neck margin was associated with decreased OS (11.1 vs. 17.3 months, p = 0.01) on univariate analysis. On multivariate analysis poor histologic grade (p = 0.007), increased tumor size (p = 0.003), and a positive retroperitoneal margin (p = 0.009) were independently associated with decreased OS, but positive FS neck margin was not. Of the 53 patients with positive FS, 41 underwent additional neck resection and 23 were converted to R0. On permanent section, R0 neck margin was achieved in 322 patients (84 %), R1 in 37 patients (10 %), and R1 converted to R0 in 23 patients (6 %). Both the converted and the R1 groups had significantly poorer OS than the R0 group (11.3 vs. 11.1 vs. 17.3 months respectively; p = 0.04)., Conclusions: Positive FS margin at the pancreatic neck during PD for PDAC is associated with poor survival. Extending the neck resection after a positive FS to achieve R0 margin status does not appear to improve OS.

Introduction: Staging laparoscopy (SL) can identify occult, subradiographic metastatic (M1) disease in patients with gastric or gastroesophageal (G/GEJ) cancer who are unlikely to benefit from gastrectomy. The purpose of this study is to determine the yield of repeat SL following neoadjuvant therapy for G/GEJ adenocarcinoma after initial negative pretreatment SL., Methods: Retrospective review of a prospective database identified patients with locoregionally advanced (T3-4Nany or TanyN+) G/GEJ adenocarcinoma who underwent pretreatment SL. The yield of repeat SL following neoadjuvant therapy was determined., Results: From 1994 to 2010, 276 patients with locoregionally advanced G/GEJ adenocarcinoma were identified, of whom 244 proceeded to operation after neoadjuvant therapy, at a median time of 105 days. One hundred sixty-four patients (67 %) underwent repeat SL, and 80 patients (33 %) proceeded directly to laparotomy. Occult M1 disease was identified in 12 (7.3 %) and 6 (7.5 %) patients, respectively. In the repeat SL cohort, M1 disease was identified at laparoscopy in nine patients (5.5 %). M1 disease not identified by laparoscopy was discovered at laparotomy in three patients (1.8 %). The median follow-up for the study population was 31 months. For patients with M1 disease, median overall survival was 15 months, versus 41 months for patients resected without M1 disease (p < 0.0001)., Conclusions: Occult, subradiographic M1 disease develops in approximately 7 % of patients following neoadjuvant therapy for locoregionally advanced G/GEJ adenocarcinoma. These patients have poor prognosis, and repeat SL can be a valuable tool in selecting patients with locoregionally advanced G/GEJ tumors for potentially curative resection after neoadjuvant therapy.

Introduction: Outcome after hepatic resection for colorectal cancer liver metastases (CRLM) is heterogeneous and accurate predictors of survival are lacking. This study analyzes the prognostic relevance of pathologic details of the primary colorectal tumor in patients undergoing hepatic resection for CRLM., Methods: Retrospective review of a prospective database identified patients who underwent resection for CRLM. Clinicopathological variables were investigated and their association with outcome was analyzed., Results: From 1997-2007, 1,004 patients underwent hepatic resection for CRLM. The median follow-up was 59 months with a 5-year survival of 47%. Univariate analysis identified nine factors associated with poor survival; three of these related to the primary tumor: lymphovascular invasion (LVI, p<0.0001), perineural invasion (p=0.005), and degree of regional lymph node involvement (N0 vs. N1 vs. N2, p<0.0001). Multivariate analysis identified seven factors associated with poor survival, two of which related to the primary tumor: LVI (hazard ratio (HR) 1.3, 95% confidence interval (CI) 1.06-1.64, p=0.01) and degree of regional lymph node involvement [N1 (HR 1.3, 95% CI 1.04-1.69, p=0.02) vs. N2 (HR 1.7, 95% CI 1.27-2.21, p<0.0005)]. A significant decrease in survival along the spectrum of patients ranging from LVI negative/N0 to LVI positive/N2 was present. Patients who were LVI-positive/N2 had a median survival of 40 months compared with 74 months for patients who were LVI-negative/NO (p<0.0001)., Conclusions: Histopathologic details of the primary colorectal tumor, particularly LVI and the detailed assessment of the degree of lymph node involvement, are strong predictors of survival. Future biomarker studies should consider exploring factors related to the primary colorectal tumor.