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Purpose: A combination of fluorouracil, leucovorin, and oxaliplatin (FOLFOX) is the standard for adjuvant therapy of resected early-stage colon cancer (CC). Oxaliplatin leads to lasting and disabling neurotoxicity. Reserving the regimen for patients who benefit from oxaliplatin would maximize efficacy and minimize unnecessary adverse side effects., Methods: We trained a new machine learning model, referred to as the colon oxaliplatin signature (COLOXIS) model, for predicting response to oxaliplatin-containing regimens. We examined whether COLOXIS was predictive of oxaliplatin benefits in the CC adjuvant setting among 1,065 patients treated with 5-fluorouracil plus leucovorin (FULV; n = 421) or FULV + oxaliplatin (FOLFOX; n = 644) from NSABP C-07 and C-08 phase III trials. The COLOXIS model dichotomizes patients into COLOXIS+ (oxaliplatin responder) and COLOXIS- (nonresponder) groups. Eight-year recurrence-free survival was used to evaluate oxaliplatin benefits within each of the groups, and the predictive value of the COLOXIS model was assessed using the P value associated with the interaction term (int P ) between the model prediction and the treatment effect., Results: Among 1,065 patients, 526 were predicted as COLOXIS+ and 539 as COLOXIS-. The COLOXIS+ prediction was associated with prognosis for FULV-treated patients (hazard ratio [HR], 1.52 [95% CI, 1.07 to 2.15]; P = .017). The model was predictive of oxaliplatin benefits: COLOXIS+ patients benefited from oxaliplatin (HR, 0.65 [95% CI, 0.48 to 0.89]; P = .0065; int P = .03), but COLOXIS- patients did not (COLOXIS- HR, 1.08 [95% CI, 0.77 to 1.52]; P = .65)., Conclusion: The COLOXIS model is predictive of oxaliplatin benefits in the CC adjuvant setting. The results provide evidence supporting a change in CC adjuvant therapy: reserve oxaliplatin only for COLOXIS+ patients, but further investigation is warranted.

Importance: Oxaliplatin added to fluorouracil plus leucovorin therapy for patients with colon cancer has been shown to provide significant but modest absolute benefit for disease-free survival. However, acute and chronic neurotoxic effects from this regimen underscore the need for markers that predict oxaliplatin benefit., Objective: To test our hypothesis that molecular subtypes of colon cancer would be associated with differential prognosis and benefit from oxaliplatin added to fluorouracil plus leucovorin therapy., Design, Setting, and Participants: Participants in the NSABP C-07 trial were divided into discovery (n = 848) and validation (n = 881) cohorts based on the order of tissue block submission. A reestimated centroid using 72 genes was used to determine Colorectal Cancer Assigner subtypes and their association with oxaliplatin benefit in the discovery cohort. The validation cohort was examined with a locked-down algorithm for subtype classification and statistical analysis plan. Post hoc analysis included examination of the entire cohort with Colorectal Cancer Assigner, Colorectal Cancer Subtype (CCS), and Consensus Molecular Subtype (CMS) methods., Interventions: Fluorouracil plus leucovorin with or without oxaliplatin., Main Outcomes and Measures: Percent recurrence-free survival., Results: Among 1729 patients, 744 (43%) were female and mean (SD) age was 58 (11) years. Although C-07 participants with stage III disease with an enterocyte subtype showed a statistically significant benefit from oxaliplatin in the discovery cohort (hazard ratio, 0.22 [95% CI, 0.09-0.56]; P = .001 [N = 65]), no statistically significant benefit was observed in the validation cohort (hazard ratio, 0.53 [95% CI, 0.22-1.24]; P = .14 [N = 70]). The stemlike subtype was associated with poor prognosis and lack of benefit from oxaliplatin treatment (HR, 0.99 [95% CI, 0.73-1.34]; P = .96 [N = 367]). Examination of the different subtyping methods shows that all 3 methods robustly identified patients with poor prognosis (stemlike, CCS-3, and CMS-4) in both stage II and III., Conclusions and Relevance: Patients with stemlike tumors may be appropriate for clinical trials testing experimental therapies because stemlike tumors were robustly identified and associated with a poor prognosis regardless of stage or chemotherapy regimen. The clinical utility of using subtyping for the identification of patients for treatment with oxaliplatin requires validation in independent clinical trial cohorts., Trial Registration: clinicaltrials.gov Identifier: NCT00004931., Competing Interests: Disclosures: Dr Yothers has acted in a consulting/advisory role for Pharmacyclics. No other disclosures are reported.

Purpose: The optimal chemotherapy regimen administered concurrently with preoperative radiation therapy (RT) for patients with rectal cancer is unknown. National Surgical Adjuvant Breast and Bowel Project trial R-04 compared four chemotherapy regimens administered concomitantly with RT., Patients and Methods: Patients with clinical stage II or III rectal cancer who were undergoing preoperative RT (45 Gy in 25 fractions over 5 weeks plus a boost of 5.4 Gy to 10.8 Gy in three to six daily fractions) were randomly assigned to one of the following chemotherapy regimens: continuous intravenous infusional fluorouracil (CVI FU; 225 mg/m(2), 5 days per week), with or without intravenous oxaliplatin (50 mg/m(2) once per week for 5 weeks) or oral capecitabine (825 mg/m(2) twice per day, 5 days per week), with or without oxaliplatin (50 mg/m(2) once per week for 5 weeks). Before random assignment, the surgeon indicated whether the patient was eligible for sphincter-sparing surgery based on clinical staging. The surgical end points were complete pathologic response (pCR), sphincter-sparing surgery, and surgical downstaging (conversion to sphincter-sparing surgery)., Results: From September 2004 to August 2010, 1,608 patients were randomly assigned. No significant differences in the rates of pCR, sphincter-sparing surgery, or surgical downstaging were identified between the CVI FU and capecitabine regimens or between the two regimens with or without oxaliplatin. Patients treated with oxaliplatin experienced significantly more grade 3 or 4 diarrhea (P < .001)., Conclusion: Administering capecitabine with preoperative RT achieved similar rates of pCR, sphincter-sparing surgery, and surgical downstaging compared with CVI FU. Adding oxaliplatin did not improve surgical outcomes but added significant toxicity. The definitive analysis of local tumor control, disease-free survival, and overall survival will be performed when the protocol-specified number of events has occurred., (© 2014 by American Society of Clinical Oncology.)

Purpose: Major concerns surround combining chemotherapy with bevacizumab in patients with colon cancer presenting with an asymptomatic intact primary tumor (IPT) and synchronous yet unresectable metastatic disease. Surgical resection of asymptomatic IPT is controversial., Patients and Methods: Eligibility for this prospective, multicenter phase II trial included Eastern Cooperative Oncology Group (ECOG) performance status 0 to 1, asymptomatic IPT, and unresectable metastases. All received infusional fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) combined with bevacizumab. The primary end point was major morbidity events, defined as surgical resection because of symptoms at or death related to the IPT. A 25% major morbidity rate was considered acceptable. Secondary end points included overall survival (OS) and minor morbidity related to IPT requiring hospitalization, transfusion, or nonsurgical intervention., Results: Ninety patients registered between March 2006 and June 2009: 86 were eligible with follow-up, median age was 58 years, and 52% were female. Median follow-up was 20.7 months. There were 12 patients (14%) with major morbidity related to IPT: 10 required surgery (eight, obstruction; one, perforation; and one, abdominal pain), and two patients died. The 24-month cumulative incidence of major morbidity was 16.3% (95% CI, 7.6% to 25.1%). Eleven IPTs were resected without a morbidity event: eight for attempted cure and three for other reasons. Two patients had minor morbidity events only: one hospitalization and one nonsurgical intervention. Median OS was 19.9 months (95% CI, 15.0 to 27.2 months)., Conclusion: This trial met its primary end point. Combining mFOLFOX6 with bevacizumab did not result in an unacceptable rate of obstruction, perforation, bleeding, or death related to IPT. Survival was not compromised. These patients can be spared initial noncurative resection of their asymptomatic IPT.

Purpose: The National Surgical Adjuvant Breast and Bowel Project (NSABP) C-07 trial demonstrated that the addition of oxaliplatin to fluorouracil plus leucovorin (FULV) improved disease-free survival (DFS) in patients with stage II or III colon cancer. This analysis is the first publication of overall survival (OS) for the NSABP C-07 study. We updated DFS and examined both end points in clinically relevant patient subsets., Patients and Methods: Other studies have identified patients age 70 or older and those with stage II disease as patient subsets in which oxaliplatin may not be effective. We investigated toxicity as a driver of divergent outcomes in these subsets., Results: In all, 2,409 eligible patients with follow-up were randomly assigned to either FULV (FU 500 mg/m(2) by intravenous [IV] bolus weekly for 6 weeks; leucovorin 500 mg/m(2) IV weekly for 6 weeks of each 8-week cycle for three cycles) or FLOX (FULV plus oxaliplatin 85 mg/m(2) IV on days 1, 15, and 29 of each cycle). With 8 years median follow-up, OS was similar between treatment groups (hazard ratio [HR], 0.88; 95% CI, 0.75 to 1.02; P = .08). FLOX remained superior for DFS (HR, 0.82; 95% CI, 0.72 to 0.93; P = .002). The effect of oxaliplatin on OS did not differ by stage of disease (interaction P = .38 for OS; interaction P = 0.37 for DFS) but did vary by age for OS (younger than age 70 v 70+ interaction P = .039). There was a similar trend for DFS (interaction P = .073). Oxaliplatin significantly improved OS in patients younger than age 70 (HR, 0.80; 95% CI, 0.68 to 0.95; P = .013), but no positive effect was evident in older patients., Conclusion: Overall, the addition of oxaliplatin to FULV has not been proven to extend OS in this trial, but the DFS effect remained strong. Unplanned subset analyses suggest a significant OS effect of oxaliplatin in patients younger than age 70.

Purpose: The National Surgical Adjuvant Breast and Bowel Project C-08 trial was designed to investigate the safety and efficacy of adding bevacizumab to modified FOLFOX6 (mFOLFOX6; ie, infusional/bolus fluorouracil, leucovorin, and oxaliplatin) for the adjuvant treatment of patients with stages II to III colon cancer., Methods: Patients received mFOLFOX6 every 2 weeks for 26 weeks alone or modified as FOLFOX6 + bevacizumab (5 mg/kg every 2 weeks for 52 weeks [ie, experimental group]). The primary end point was disease-free survival (DFS)., Results: Among 2,672 analyzed patients, demographic factors were well balanced by treatment. With a median follow-up of 35.6 months, the addition of bevacizumab to mFOLFOX6 did not result in an overall significant increase in DFS (hazard ratio [HR], 0.89; 95% CI, 0.76 to 1.04; P = .15). The point estimates for 3-year DFS for the overall population were 77.4% and 75.5% for the experimental and control arms, respectively. For patients with stages II and III diseases, these same estimates were 87.4% and 84.7%, respectively, for stage II and 74.2% and 72.4%, respectively, for stage III. Exploratory analyses found that the effect of bevacizumab on DFS was different before and after a 15-month landmark (time-by-treatment interaction P value < .0001). Bevacizumab had a strong effect before the landmark (HR, 0.61; 95% CI, 0.48 to 0.78; P < .001) but no significant effect after (HR, 1.22; 95% CI, 0.98 to 1.52; P = .076)., Conclusion: Bevacizumab for 1 year with mFOLFOX6 does not significantly prolong DFS in stages II and III colon cancer. However, a significant but transient effect during bevacizumab exposure was observed in the experimental arm. We postulate that this observation reflects a biologic effect during bevacizumab exposure. Given the lack of improvement in DFS, the use of bevacizumab cannot be recommended for use in the adjuvant treatment of patients with colon cancer.

Background: The objective of this study is to conduct a pooled analysis of National Surgical Adjuvant Breast and Bowel Project (NSABP) colon trials involving surgery and surgery plus 5-fluorouracil and leucovorin (5-FU/LV) to compare survival and establish a baseline from which to evaluate future studies., Methods: All patients enrolled in NSABP adjuvant trials C-01 through C-05 with stage II and III disease who were treated with surgery or with surgery plus 5-FU/LV were examined for overall survival (OS), disease-free survival (DFS), and recurrence-free interval (RFI). Time-to-event by treatment group was examined using adjusted Kaplan-Meier estimates and multivariable Cox regression analysis., Results: There were 2,966 eligible patients: 693 (23%) surgery and 2,273 (77%) surgery plus 5-FU/LV; 1,255 (42%) stage II and 1,711 (58%) stage III. Age > or =60 years [hazard ratio (HR) = 1.36, P < 0.0001], male gender (HR = 1.20, P = 0.0012), and more nodes positive or fewer nodes examined (P < 0.0001) were associated with worse survival. At 5 years, the adjusted OS was 0.62 [confidence interval (CI) = 0.60-0.63] in the surgery group and 0.76 (CI = 0.74-0.78) in the surgery plus 5-FU/LV group. Treatment with 5-FU/LV was associated with improved outcome compared with surgery: OS (HR = 0.62, P < 0.0001), DFS (HR = 0.66, P < 0.0001) and RFI (HR = 0.64, P < 0.0001). Improved OS with adjuvant treatment was seen in both stage II (HR = 0.58, 95% CI = 0.48-0.71) and stage III disease (HR = 0.65, 95% CI = 0.55-0.75)., Conclusions: This analysis demonstrates that treatment of colon cancer patients with 5-FU/LV following surgery provides benefit over surgery alone and can provide anticipated survival outcomes with which to compare modern adjuvant trials.

Purpose: The National Surgical Adjuvant Breast and Bowel Project C-08 trial was designed to investigate the safety and effectiveness of adding bevacizumab to modified infusional fluorouracil, leucovorin, and oxaliplatin (FOLFOX) 6 regimen for the adjuvant treatment of patients with stage II or III colon cancer. We present safety information in advance of the planned analysis of efficacy., Patients and Methods: Among 2,710 randomly assigned patients, demographic factors were balanced. Patients received modified FOLFOX6 every 2 weeks x 12 or modified FOLFOX6 plus bevacizumab (5 mg/kg every 2 weeks x 26, experimental group)., Results: Overall rates of grade 4 or 5 toxicities were nearly identical in the FOLFOX6 and FOLFOX6 plus bevacizumab arms (15.2% and 15.0%, respectively). Six-month mortality rates were 0.96% and 0.90% for the control and experimental groups, respectively. Grade 3+ toxicities that occurred more often in the experimental arm versus control arm included hypertension (12% v 1.8%, respectively), wound complications (abdominal incisional hernia or infusion port dehiscence/inflammation; 1.7% v 0.3%, respectively), pain (11.1% v 6.3%, respectively), and proteinuria (2.7% v 0.8%, respectively). Grade 2+ neuropathy was increased in the experimental arm versus the control arm (grade 2, 33% v 29%, respectively; grade 3, 16% v 14%, respectively; and grade 4, < 1% each). In the experimental arm versus control arm, significantly less thrombocytopenia (1.4% v 3.4%, respectively) and fewer allergic reactions (3.1% v 4.7%, respectively) were observed. Advanced age was associated with a significantly greater rate of grade 4 and 5 toxicities regardless of treatment., Conclusion: Bevacizumab with modified FOLFOX6 is well tolerated in the surgical adjuvant setting in these patients. No significant increase in GI perforation, hemorrhage, arterial or venous thrombotic events, or death with the addition of bevacizumab to modified FOLFOX6 has been observed. Follow-up for potential delayed adverse effects and efficacy is ongoing.

Purpose: This phase III clinical trial evaluated the impact on disease-free survival (DFS) of adding oxaliplatin to bolus weekly fluorouracil (FU) combined with leucovorin as surgical adjuvant therapy for stage II and III colon cancer., Patients and Methods: Patients who had undergone a potentially curative resection were randomly assigned to either FU 500 mg/m2 intravenous (IV) bolus weekly for 6 weeks plus leucovorin 500 mg/m2 IV weekly for 6 weeks during each 8-week cycle for three cycles (FULV), or the same FULV regimen with oxaliplatin 85 mg/m2 IV administered on weeks 1, 3, and 5 of each 8-week cycle for three cycles (FLOX)., Results: A total of 2,407 patients (96.6%) of the 2,492 patients randomly assigned were eligible. Median follow-up for patients still alive is 42.5 months. The hazard ratio (FLOX v FULV) is 0.80 (95% CI, 0.69 to 0.93), a 20% risk reduction in favor of FLOX (P < .004). The 3- and 4-year disease-free survival (DFS) rates were 71.8% and 67.0% for FULV and 76.1% and 73.2% for FLOX, respectively. Grade 3 neurosensory toxicity was noted in 8.2% of patients receiving FLOX and in 0.7% of those receiving FULV (P < .001). Hospitalization for diarrhea associated with bowel wall thickening occurred in 5.5% of the patients receiving FLOX and in 3.0% of the patients receiving FULV (P < .01). A total of 1.2% of patients died as a result of any cause within 60 days of receiving chemotherapy, with no significant difference between regimens., Conclusion: The addition of oxaliplatin to weekly FULV significantly improved DFS in patients with stage II and III colon cancer. FLOX can be recommended as an effective option in clinical practice.

Purpose: The primary aim of this study was to compare the relative efficacy of oral uracil and tegafur (UFT) plus leucovorin (LV) with the efficacy of weekly intravenous fluorouracil (FU) plus LV in prolonging disease-free survival (DFS) and overall survival (OS) after primary surgery for colon carcinoma., Patients and Methods: Between February 1997 and March 1999, 1,608 patients with stage II and III carcinoma of the colon were randomly assigned to receive either oral UFT+LV or intravenous FU+LV., Results: Of the total patients, 47% had stage II colon cancer, and 53% had stage III colon cancer. Median follow-up time was 62.3 months. The estimated hazard ratio (HR) for OS of patients who received UFT+LV versus that of patients who received FU+LV was 1.014 (95% CI, 0.825 to 1.246). The estimated HR for DFS was 1.004 (95% CI, 0.847 to 1.190). Cox proportional hazards model analyses with regard to age (< 60 v > or = 60 years), stage, or number of involved nodes (none v one to three v > or = four nodes) revealed no interaction with OS or DFS. Toxicity was similar in the two groups. In the UFT+LV arm, 38.2% of patients experienced any grade 3 or 4 toxic event compared with 37.8% of patients in the FU+LV arm. Primary quality-of-life end points did not differ between the two regimens, although convenience of care analysis favored UFT+LV., Conclusion: UFT+LV achieved similar DFS and OS when compared with an intravenous, weekly, bolus FU+LV regimen. The two regimens were equitoxic and generally well tolerated.

Purpose: To compare the efficacy and the toxicity of cisplatin and 5-fluorouracil (PF) and mitomycin C, vincristine, cisplatin and 5-fluorouracil (MVPF) in patients with metastatic large bowel cancer., Patients and Methods: A total of 94 patients with no prior chemotherapy and measurable metastatic large bowel cancer were randomly assigned to one of the two treatment regimens. Eastern Cooperative Oncology Group (ECOG) criteria were used to evaluate response and toxicity., Results: Fifty patients were randomized to PF and 44 to MVPF. Toxicity was evaluable in all patients except one; response was evaluable in 40 and 31, with response rate of 13 and 42%, respectively. Intent-to-treat analysis showed a response rate of 12 and 32%, respectively (p = 0.076), where it was assumed that none of the ineligible or unevaluable patients responded. Median survival for all patients was 9 months, with no difference between PF and MVPF. ECOG Performance Status (0 vs. 1), weight loss (< or =10 vs. >10%) and site of metastatic lesion had statistically significant impact on survival. MVPF was definitely more toxic than PF (p < 0.000005)., Conclusion: Both treatment regimens showed clinical activity. The MVPF regimen resulted in more responses than PF, no improvement in survival, and more toxicity., (Copyright 2004 S. Karger AG, Basel)

Surgical resection for selected patients with hepatic metastases from colorectal cancer can cure approximately one-fourth of these patients. The addition of regional chemotherapy as an attempt to improve this statistic has been extensively investigated in clinical trials. As part of a multidisciplinary educational program, a series of debates on various topics in oncology are held at the Roswell Park Cancer Institute, Buffalo, New York, involving the medical, surgical, and radiation oncology departments. One such debate focused on the use of regional chemotherapy after potentially curative resection of hepatic metastases from colorectal cancer. The representative medical and surgical oncology fellows (N.I.K. and B.P.M.), with guidance from their respective mentors (C.G.L., J.F.G., and N.J.P.), presented concise reviews from the literature arguing for and against the use of regional chemotherapy in this setting. They appear as Parts 1 and 2 in this article. This exercise is purely educational and does not in any way reflect the opinion or the clinical practice of the authors. ., (Copyright 2002 Wiley-Liss, Inc.)

Background: The conviction that postoperative radiotherapy and chemotherapy represent an acceptable standard of care for patients with Dukes' B (stage II) and Dukes' C (stage III) carcinoma of the rectum evolved in the absence of data from clinical trials designed to determine whether the addition of radiotherapy results in improved disease-free survival and overall survival. This study was carried out to address this issue. An additional aim was to determine whether leucovorin (LV)-modulated 5-fluorouracil (5-FU) is superior to the combination of 5-FU, semustine, and vincristine (MOF) in men., Patients and Methods: Eligible patients (n = 694) with Dukes' B or C carcinoma of the rectum were enrolled in National Surgical Adjuvant Breast and Bowel Project (NSABP) Protocol R-02 from September 1987 through December 1992 and were followed. They were randomly assigned to receive either postoperative adjuvant chemotherapy alone (n = 348) or chemotherapy with postoperative radiotherapy (n = 346). All female patients (n = 287) received 5-FU plus LV chemotherapy; male patients received either MOF (n = 207) or 5-FU plus LV (n = 200). Primary analyses were carried out by use of a stratified log-rank statistic; P values are two-sided., Results: The average time on study for surviving patients is 93 months as of September 30, 1998. Postoperative radiotherapy resulted in no beneficial effect on disease-free survival (P =.90) or overall survival (P =.89), regardless of which chemotherapy was utilized, although it reduced the cumulative incidence of locoregional relapse from 13% to 8% at 5-year follow-up (P =.02). Male patients who received 5-FU plus LV demonstrated a statistically significant benefit in disease-free survival at 5 years compared with those who received MOF (55% versus 47%; P =.009) but not in 5-year overall survival (65% versus 62%; P =.17)., Conclusions: The addition of postoperative radiation therapy to chemotherapy in Dukes' B and C rectal cancer did not alter the subsequent incidence of distant disease, although there was a reduction in locoregional relapse when compared with chemotherapy alone.

Cryosurgery of hepatic metastases from colorectal carcinoma is a form of local therapy for unresectable disease. After curative resection, failures occur in the liver, and at extrahepatic sites. This pilot study evaluated the toxicity and tolerance to cryotherapy and intraoperative chemotherapy for unresectable hepatic metastases from colorectal cancer. If after exploratory celiotomy for potential curative resection of hepatic metastases the patient was deemed unresectable because of location and/or number of lesions, cryosurgery and intraoperative chemotherapy with systemic 5-fluorouracil 600 mg/m2 and leucovorin 500 mg/m2 was performed. Four patients were treated with cryochemotherapy. All patients developed toxicity. Two patients developed grade II leukopenia on Postoperative Days 2 and 12, and grades II and III diarrhea on Postoperative Days 5 and 7, respectively. Grade III hyperbilirubinemia and thrombocytopenia occurred in one patient on Postoperative Days 3 and 7. Acute respiratory distress syndrome, postoperative ileus, and grade II mucositis occurred in one patient each. All patients had delays and dose reductions on their subsequent chemotherapy treatments secondary to toxicity. Two patients had disease progression, one had stable disease. and one is "disease free." Combining the tumoricidal effects of chemotherapy and cryosurgery is in theory a good concept. However, the toxicity of 5-FU and leucovorin is enhanced by this approach.

A phase I and pharmacokinetics study was carried out of floxuridine (FdUrd) modulated by leucovorin (LV) given on the Roswell Park regimen (LV given at 500 mg/m2 by 2-h infusion and FdUrd given by i.v. push at 1 h after the start of LV infusion, treatment being given weekly x 6). The dose-limiting toxicity was diarrhea; the MTD and recommended dose for phase II studies was 1,650 mg/m2 per week of FdUrd. The dose-response curve was steep, with 3/3 patients treated at a dose of 1,750 mg/m2 developing grade IV diarrhea. With this schedule there was no significant mucositis. Pharmacokinetic parameters showed very wide interpatient variability. Plasma decay was biphasic with a t1/2 beta of approximately 2 h. Plasma clearance was high (> 200 1 h-1). No correlation between pharmacokinetic parameters and toxicity could be identified.

Background: A prospective trial was conducted involving 16 patients with colorectal adenocarcinoma using a regimen of continuous-infusion octreotide acetate (Sandostatin [octreotide acetate], Sandoz, East Hanover, NJ for the treatment of severe diarrhea induced by the weekly schedule of 5-fluorouracil (5-FU) in combination with leucovorin who were refractory to opiate therapy., Methods: Fifteen patients had tissue-documented metastatic colorectal adenocarcinoma. An additional patient was treated adjuvantly. Fifteen patients were treated with chemotherapy consisting of 5-FU and high-dose leucovorin. The octreotide acetate regimen used was a continuous infusion of 50 micrograms/h for 12 hours followed by 100 micrograms/h for 12 hours and subsequently 150 micrograms/h for 72 hours. All patients were previous failures of diphenoxylate atropine (Lomotil diphenoxalate], Searle, Chicago, IL) given 2.5 mg orally after each loose bowel movement, but no more than 20 mg in a 24-hour period. Opiate therapy was not continued beyond 48 hours. All patients also were treated with bowel rest (nothing by mouth) and intravenous fluid hydration as well as octreotide acetate., Results: Complete resolution of diarrhea was seen in 15 of 16 patients (94%). In 4 patients this was accomplished during the 100 micrograms/h infusion, and in 11 patients during the 150 micrograms/h infusion. Recurrence of diarrhea was seen in two patients after a complete cycle of octreotide acetate. Both patients were restarted at 150 micrograms/h for 72 hours of octreotide acetate with resolution of the diarrhea within 36 hours of the infusion. No toxicity related to octreotide acetate was seen in this trial., Conclusion: The continuous-infusion regimen of octreotide acetate 150 micrograms/h is an effective and safe schedule for the treatment of chemotherapy-induced diarrhea together with bowel rest and intravenous fluid hydration in a group of patients in whom the majority were treated with the weekly schedule of 5-FU and high-dose leucovorin.

Five-fluorouracil (5-FU) has become the standard chemotherapeutic agent for the treatment of advanced colorectal carcinoma. It has been used as a single agent and in combination with other chemotherapeutic agents for the treatment of advanced disease. Conflicting experiences have been reported with all these therapeutic programs and a review of these studies reveals failure to take into consideration the factors determining survival and response. These factors consist of performance status, weight loss, hepatomegaly, previous chemotherapy treatment, prior radiotherapy treatment, and resected versus unresected primaries. The purpose of this study is to examine the various claims for therapeutic efficacy of drugs used in all stages of colorectal carcinoma. This will consist of a review of single agent systemic chemotherapy for advanced colorectal carcinoma, combination chemotherapy for advanced colorectal carcinoma, regional infusion, and adjuvant chemotherapy following curative resection.

A total of 24 patients with advanced colorectal adenocarcinoma were entered into a phase I-II study of 5-fluorouracil (5-FU) and cisplatin, 21 of whom had previously received 5-FU. The starting dose of cisplatin was 20 mg/m2 diluted in 1000 cc normal saline, given over 20 h daily for 5 days, together with 600 mg/m2 5-FU diluted in 1000 cc fluid, given simultaneously over 20 h daily for 5 days. This regiment was given every 4 weeks. The dose-limiting toxicity was renal and cumulative. All 24 patients were evaluable for toxicity. Of 12 patients on the above-mentioned starting dose, 8 underwent a cisplatin dose reduction to 15 mg/m2 due to a progressive decrease in creatinine clearance following the second or third course of treatment. Of 12 patients who started cisplatin at 15 mg/m2 and 5-FU at 600 mg/m2, 11 were maintained at this dose. A WBC nadir count of less than 2000/mm3 was seen in four patients. Thrombocytopenia occurred in three patients who received 15 mg/m2 cisplatin and 600 mg/m2 5-FU. In all, 21 of the 24 patients had objectively measurable disease and were also evaluable for response as follows: 1 complete response, 2 partial responses, 1 case of stable disease, and 17 patients with progressive disease.

Following the observation of antitumor activity for the combination of 5-fluorouracil (5-FU) and cisplatin in metastatic colorectal carcinoma, the combination of 5-FU and iproplatin was tested, also in colorectal carcinoma, in the hope of attaining equivalent activity without the nephrotoxicity observed with 5-FU/cisplatin. However, no responses were achieved with 5-FU/iproplatin.

Plasma pharmacokinetics of high-dose (500 mg/m2) leucovorin calcium (dl-5-formyltetrahydrofolic acid [dl-CF]) and fluorouracil (FUra) have been evaluated in patients with advanced colorectal cancer treated with the combination of FUra and dl-CF by two different intravenous (IV) schedules: (A) In patients with no prior chemotherapy, dl-CF was administered by a two-hour IV infusion and FUra by rapid IV injection one hour after the start of the dl-CF infusion and (B) in previously treated patients, dl-CF and FUra were administered by five-day continuous IV infusion (CI). Following the two-hour infusion of dl-CF, mean peak plasma concentration and elimination half-life of I-5-formyltetrahydrofolic acid (I-CF) were 24 +/- 6 mumol/L and 0.8 +/- 0.1 hour, respectively. CI of dl-CF over five days yielded a mean steady-state plasma level of I-CF of only 1.2 +/- 0.5 mumol/L. Peak and steady-state plasma concentrations of the metabolite 5-methyl tetrahydrofolic acid were comparable in the two schedules (17 +/- 8 mumol/L for the two-hour infusion and 12 +/- 5 mumol/L for the CI). Areas under the concentration v time curve (AUC) of total reduced folates were significantly greater under conditions of CI: 89.0 v 16.7 mmol/L/min for the two-hour infusion. In tumor tissue, 5,10-methylenetetrahydrofolate increased eight-fold two to four hours following the two-hour infusion and two-fold during the CI of dl-CF and FUra. Inhibition of thymidylate synthase (dTMP-S) by the two-hour and CI infusion schedules were 66% v 39%, respectively. The observed differences in the intracellular dTMP-S folate cofactor pools and the degree of inhibition of dTMP-S achieved in patients treated by two different schedules may be due to differences in the biochemical properties and/or to differences in the modulation of FUra metabolism by folate of tumor tissues obtained from newly diagnosed and previously treated patients.

The data from an ongoing 3-arm prospective study of 72 patients with advanced colorectal carcinoma is presented. The 3 regimens are as follows: Regime 1 (every 4 weeks)--5-fluorouracil (FUra) (450 mg/m2 iv bolus daily for 5 days, then 200 mg/m2 iv bolus every other day for 6 doses); regime 2 (every week for 4 weeks, then every other week)--methotrexate (MTX) (50 mg/m2 in a 4-hour infusion) followed by FUra (600 mg/m2 iv bolus); regime 3 (weekly for 6 weeks followed by a 2-week rest period)--D,L-leucovorin (D,L-CF) (500 mg/m2 in a 2-hour infusion) with FUra (600 mg/m2 iv bolus) 1 hour after the D,L-CF infusion began. All monitoring lesions except lung were documented by tissue biopsy. Thirteen of 18 patients in the FUra + D,L-CF arm were evaluable for response. Six of the 13 patients (46%) have had a partial response. The duration of the 6 responses has been 11, 8, 7, 4, 3 and 3 months. In patients with liver metastases as the monitoring lesion, a dramatic improvement in liver function tests has been seen during the first 2 courses (12 weeks) of treatment, but this was not sustained. The toxicity of FUra + D,L-CF was predominantly gastrointestinal; unlike with FUra alone, myelosuppression was not predominant.