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Multidisciplinary management of rectal cancer has rapidly evolved over the last several years. This review describes recent data surrounding total neoadjuvant therapy, organ preservation, and management of lateral pelvic lymph nodes. It then presents our treatment algorithm for management of rectal cancer at The University of Texas MD Anderson Cancer Center in the context of this and other existing literature. As part of this discussion, the review describes how we tailor management based upon both patient and tumor‐related factors in an effort to optimize patient outcomes. [ABSTRACT FROM AUTHOR]

Objective: External exposures, the host, and the microbiome interact in oncology. We aimed to investigate tumoral microbiomes in young-onset rectal cancers (YORCs) for profiles potentially correlative with disease etiology and biology. Background: YORC is rapidly increasing, with 1 in 4 new rectal cancer cases occurring under the age of 50 years. Its etiology is unknown. Methods: YORC (<50 y old) or later-onset rectal cancer (LORC, ≥50 y old) patients underwent pretreatment biopsied of tumor and tumor-adjacent normal (TAN) tissue. After whole genome sequencing, metagenomic analysis quantified microbial communities comparing tumors versus TANs and YORCs versus LORCs, controlling for multiple testing. Response to neoadjuvant therapy (NT) was categorized as major pathological response (MPR, ≤10% residual viable tumor) versus non-MPR. Results: Our 107 tumors, 75 TANs from 37 (35%) YORCs, and 70 (65%) LORCs recapitulated bacterial species were previously associated with colorectal cancers (all P< 0.0001). YORC and LORC tumoral microbiome signatures were distinct. After NT, 13 patients (12.4%) achieved complete pathologic response, whereas MPR occurred in 47 patients (44%). Among YORCs, MPR was associated with Fusobacterium nucleaum, Bacteroides dorei, and Ruminococcus bromii (all P< 0.001), but MPR in LORC was associated with R. bromii (P<0.001). Network analysis of non-MPR tumors demonstrated a preponderance of oral bacteria not observed in MPR tumors. Conclusions: Microbial signatures were distinct between YORC and LORC. Failure to achieve an MPR was associated with oral bacteria in tumors. These findings urge further studies to decipher correlative versus mechanistic associations but suggest a potential for microbial modulation to augment current treatments. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the impact of neoadjuvant multi-agent systemic chemotherapy and radiation (TNT) vs neoadjuvant single-agent chemoradiation (nCRT) and multi-agent adjuvant chemotherapy on overall survival (OS), tumor downstaging, and circumferential resection margin (CRM) status in patients with locally advanced rectal cancer. Summary of Background Data: Outside of clinical trials and small institutional reports, there is a paucity of data regarding the short and long-term oncologic impact of TNT as compared to nCRT. Methods: Adult patients with stage II-III rectal adenocarcinoma were identified in the National Cancer Database [2006–2015]. Results: Out of 8,548 patients, 36% received TNT and 64% nCRT. In the cohort, 13% had a pCR and 20% a neoadjuvant rectal (NAR) score <8. In multivariable analysis, as compared to nCRT, TNT demonstrated numerically higher pCR rates (P = 0.05) but had similar incidence of positive CRM (P = 0.11). Similar results were observed with NAR scores <8 as the primary endpoint. After adjusting for confounders, OS was comparable between the 2 groups. Additional factors independently associated with lower OS included male gender, uninsured status, low income status, high comorbidity score, poorly differentiated tumors, abdominoperineal resection, and positive surgical margins (all P <0.01). In separate models, both pCR and a NAR score <8 were associated with improved OS. Conclusion: In this national cohort, TNT was not associated with better survival and/or CRM negative status in comparison with nCRT, despite numerically higher downstaging rates. Further refinement of patient selection and treatment regimens are needed to establish effective neoadjuvant platforms to improve outcomes of patients with rectal cancer. [ABSTRACT FROM AUTHOR]

Objective: Lateral pelvic lymph node (LPLN) metastases are an important cause of preventable local failure in rectal cancer. The aim of this study was to evaluate clinical and oncological outcomes following magnetic resonance imaging (MRI)-directed surgical selection for lateral pelvic lymph node dissection (LPLND) after total neoadjuvant therapy (TNT). Methods: A retrospective consecutive cohort analysis was performed of rectal cancer patients with enlarged LPLN on pretreatment MRI. Patients were categorized as LPLND or non-LPLND. The main outcomes were lateral local recurrence rate, perioperative and oncological outcomes and factors associated with decision making for LPLND. Results: A total of 158 patients with enlarged pretreatment LPLN and treated with TNT were identified. Median follow-up was 20 months (interquartile range 10–32). After multidisciplinary review, 88 patients (56.0%) underwent LPLND. Mean age was 53 (SD±12) years, and 54 (34.2%) were female. Total operative time (509 vs 429 minutes; P =0.003) was greater in the LPLND group, but median blood loss (P =0.70) or rates of major morbidity (19.3% vs 17.0%) did not differ. LPLNs were pathologically positive in 34.1%. The 3-year lateral local recurrence rates (3.4% vs 4.6%; P =0.85) did not differ between groups. Patients with LPLNs demonstrating pretreatment heterogeneity and irregular margin (odds ratio, 3.82; 95% confidence interval: 1.65–8.82) or with short-axis ≥5 mm post-TNT (odds ratio 2.69; 95% confidence interval: 1.19–6.08) were more likely to undergo LPLND. Conclusions: For rectal cancer patients with evidence of LPLN metastasis, the appropriate selection of patients for LPLND can be facilitated by a multidisciplinary MRI-directed approach with no significant difference in perioperative or oncologic outcomes. [ABSTRACT FROM AUTHOR]

BACKGROUND Neoadjuvant chemoradiotherapy followed by tumor resection and postoperative chemotherapy is the standard of care for patients with clinical stage II or III adenocarcinoma of the rectum. Significant variation exists in the receipt of postoperative chemotherapy after resection in this population. The objective of this study was to determine the demographic and clinicopathologic factors associated with the initiation of postoperative chemotherapy in elderly patients with rectal cancer and to identify potential targets for reducing treatment variation. METHODS A retrospective cohort study was performed of patients with rectal cancer ages 66 to 80 years who received neoadjuvant chemoradiotherapy and underwent radical resection in the Surveillance, Epidemiology, and End Results-linked Medicare database (1998-2007). Multivariate logistic regression was used to assess chemotherapy use in relation to patient, tumor, and treatment response characteristics. RESULTS Among 1492 patients who met the study criteria, 61.5% received adjuvant therapy with 5-fluorouracil. Pathologic stage was the strongest determinant of whether patients received postoperative chemotherapy (48.3% of patients with stage I disease, 59.6% of patients with stage II disease, and 77.6% of patients with stage III disease). Increasing age and postoperative readmission also were associated significantly with a decreased rate of adjuvant therapy initiation. CONCLUSIONS Although standard treatment guidelines for locally advanced rectal cancer include postoperative chemotherapy for all patients after neoadjuvant chemoradiotherapy and radical resection, greater than 1 in 3 patients failed to receive adjuvant therapy. Despite the absence of established evidence, treatment decisions appear to be influenced by the findings at surgical pathology. Cancer 2014;120:1162-1170. © 2014 American Cancer Society. [ABSTRACT FROM AUTHOR]

Because of the low incidence of nongastrointestinal stromal tumor (non-GIST) spindle cell sarcomas of the colon or rectum, the clinical behavior and ideal surgical treatment of these tumors and patient outcomes are poorly defined. The purpose of this study was to characterize these tumors and to determine the best surgical approach. We identified 1056 patients with non-GIST spindle cell sarcomas of the colon or rectum (1998-2010) in the National Cancer Database and collected data for each patient that included patient and tumor characteristics, tumor site (colon vs rectum), surgery type, and outcomes. The median overall survival was significantly longer in patients with rectal tumors than in those with colon tumors (P < 0.01). Patients with colon tumors who underwent anatomic surgical resection showed a trend toward longer median survival than those with no surgical treatment [hazard ratio (HR), 1.94; P = 0.09] or who underwent local excision (HR, 1.74; P = 0.09). Patients with rectal tumors did not benefit from anatomic surgical resection, but there was a trend favoring local excision (HR, 0.55; P = 0.06). Local sphincter-sparing procedures should be considered for rectal non-GIST tumors whenever technically feasible. [ABSTRACT FROM AUTHOR]

Purpose: The goal of this phase 1 trial was to determine the maximum tolerated dose (MTD) of concurrent capecitabine, bevacizumab, and erlotinib with preoperative radiation therapy for rectal cancer. Methods and Materials: Patients with clinical stage II to III rectal adenocarcinoma, within 12 cm from the anal verge, were treated in 4 escalating dose levels, using the continual reassessment method. Patients received preoperative radiation therapy with concurrent bevacizumab (5 mg/kg intravenously every 2 weeks), erlotinib, and capecitabine. Capecitabine dose was increased from 650 mg/m2 to 825 mg/m2 orally twice daily on the days of radiation therapy; erlotinib dose was increased from 50 mg orally daily in weeks 1 to 3, to 50 mg daily in weeks 1 to 6, to 100 mg daily in weeks 1 to 6. Patients underwent surgery at least 9 weeks after the last dose of bevacizumab. Results: A total of 19 patients were enrolled, and 18 patients were considered evaluable. No patient had grade 4 acute toxicity, and 1 patient had grade 3 acute toxicity (hypertension). The MTD was not reached. All 18 evaluable patients underwent surgery, with low anterior resection in 7 (39%), proctectomy with coloanal anastomosis in 4 patients (22%), posterior pelvic exenteration in 1 (6%), and abdominoperineal resection in 6 (33%). Of the 18 patients, 8 (44%) had pathologic complete response, and 1 had complete response of the primary tumor with positive nodes. Three patients (17%) had grade 3 postoperative complications (ileus, small bowel obstruction, and infection). With a median follow-up of 34 months, 1 patient developed distant metastasis, and no patient had local recurrence or died. The 3-year disease-free survival was 94%. Conclusions: The combination of preoperative radiation therapy with concurrent capecitabine, bevacizumab, and erlotinib was well tolerated. The pathologic complete response rate appears promising and may warrant further investigation. [ABSTRACT FROM AUTHOR]

Background: Circumferential resection margin (CRM) status is an important predictor of outcomes after rectal cancer operation, and is influenced not only by operative technique, but also by incorporation of a multidisciplinary treatment strategy. This study sought to develop a risk-adjusted quality metric based on CRM status to assess hospital-level performance for rectal cancer operation.Study Design: We conducted a retrospective observational cohort study of 58,374 patients with resected stage I to III rectal cancer within 1,303 hospitals who were identified from the National Cancer Database (2010 to 2015). The number of observed cases with a positive CRM (≤ 1 mm) was divided by the risk-adjusted expected number of cases with positive CRM to form the observed-to-expected (O/E) ratio. Secondary endpoint was overall survival.Results: The overall rate of CRM positivity was 15.9%. Based on the O/E ratio for 1,139 hospitals, 147 (12.9%) and 103 (9.0%) were significantly worse and better performers, respectively. The majority of hospitals (n = 570) performed as expected. Positive CRMs using criteria of 0 mm and 0.1 to 1 mm were associated with a significantly shorter 5-year overall survival of 49% and 63.5% (hazard ratio 1.67; 95% CI, 1.57 to 1.76 and hazard ratio 1.19; 95% CI, 1.12 to 1.26) than negative CRM > 1 mm of 74.1% (all p < 0.001).Conclusions: CRM-based O/E ratio is a robust hospital-based quality measure for rectal cancer operation. It allows facilities to compare their performance with that of centers of similar characteristics and helps identify underperforming, at-risk, and high-performing centers. National quality-improvement initiatives for rectal cancer should focus on ensuring high-quality data collection and providing ready access to risk-adjusted comparative metrics. [ABSTRACT FROM AUTHOR]