Survival following early-stage colon cancer: an ACCENT-based comparison of patients versus a matched international general population†.

BACKGROUND: Post-treatment survival experience of early colon cancer (CC) patients is well described in the literature, which states that cure is probable for some patients. However, comparisons of treated patients' survival versus that expected from a matched general population (MGP) are limited. PATIENTS AND METHODS: A total of 32 745 patients from 25 randomized adjuvant trials conducted from 1977 to 2012 in 41 countries were pooled. Observed long-term survival of these patients was compared with expected survival matched on sex, age, country, and year, both overall and by stage (II and III), sex, treatment [surgery, 5-fluorouracil (5-FU), 5-FU + oxaliplatin], age (<70 and 70+), enrollment year (pre/post 2000), and recurrence (yes/no). Comparisons were made at randomization and repeated conditional on survival to 1, 2, 3, and 5 years. CC and MGP equivalence was tested, and observed Kaplan-Meier survival rates compared with expected MGP rates 3 years out from each landmark. Analyses were also repeated in patients without recurrence. RESULTS: Within most cohorts, long-term survival of CC patients remained statistically worse than the MGP, though conditional survival generally improved over time. Among those surviving 5 years, stage II, oxaliplatin-treated, elderly, and recurrence-free patients achieved subsequent 3-year survival rates within 5% of the MGP, with recurrence-free patients achieving equivalence. CONCLUSIONS: Conditional on survival to 5 years, long-term survival of most CC patients on clinical trials remains modestly poorer than an MGP, but achieves MGP levels in some subgroups. These findings emphasize the need for access to quality care and improved treatment and follow-up strategies.

Impact of age and medical comorbidity on adjuvant treatment outcomes for stage III colon cancer: a pooled analysis of individual patient data from four randomized, controlled trials.

BACKGROUND: Adjuvant oxaliplatin plus capecitabine or leucovorin/5-fluorouracil (LV/5-FU) (XELOX/FOLFOX) is the standard of care for stage III colon cancer (CC); however, there is disagreement regarding oxaliplatin benefit in patients aged >70. In most analyses, the impact of medical comorbidity (MC) has not been assessed. Efficacy and safety of adjuvant XELOX/FOLFOX versus LV/5-FU were compared with respect to age and MC using pooled data from four randomized, controlled trials, selected for access to patient-level MC data and including commonly endorsed and utilized regimens. PATIENTS AND METHODS: Individual data from patients with stage III CC in NSABP C-08, XELOXA, X-ACT, and AVANT were pooled, excluding bevacizumab-treated patients. Patients were grouped by treatment, MC (low versus high), or age (<70 versus ≥70), and compared for disease-free survival (DFS), overall survival (OS), and adverse events (AEs). Multivariable Cox proportional hazards regression controlled for gender, T stage, and N stage. RESULTS: DFS benefits were shown for XELOX/FOLFOX versus LV/5-FU regardless of age or MC, although benefits were modestly attenuated for patients aged ≥70. Hazard ratios were 0.68 (P < 0.0001) and 0.77 (P < 0.014) for <70 and ≥70 age groups; 0.69 (P < 0.0001) and 0.59 (P < 0.0001) for Charlson Comorbidity Index ≤1 and >1 groups; and 0.70 (P < 0.0001) and 0.58 (P < 0.0001) for National Cancer Institute Combined Index ≤1 and >1 groups. OS was also significantly improved in all groups. Grade 3/4 serious AE rates were comparable across cohorts and MC scores and higher in patients aged ≥70. Oxaliplatin-relevant grade 3/4 AEs, including neuropathy, were comparable across ages and MC scores. CONCLUSIONS: Results further support consideration of XELOX or FOLFOX as standard treatment options for the adjuvant management of stage III CC in all age groups and in patients with comorbidities, consistent with those who were eligible for these clinical trials.

Toward optimized front-line therapeutic strategies in patients with metastatic colorectal cancer--an expert review from the International Congress on Anti-Cancer Treatment (ICACT) 2009.

Metastatic colorectal cancer is a particularly frequent and severe cancer. Patients die mainly from metastatic disease; however, the survival of these patients has dramatically improved with the progress in chemotherapeutic regimens as new routes of administration and introduction of more potent cytotoxic agents administered in sequential 5-FU-folinic acid-irinotecan/5-FU-folinic acid-oxaliplatine strategies. Biologic therapies have been also developed targeting two different pathways, angiogenesis and the epidermal growth factor receptor. Their combination with chemotherapy leads to improved progression-free survival and overall survival in some cases as the addition of cetuximab in wild-type K-Ras tumors. The objectives of this expert conference were to review the different options, the available prognostic or predictive factors to optimally guide the treatment.

Effect of time interval between surgery and preoperative chemoradiotherapy with 5-fluorouracil or 5-fluorouracil and oxaliplatin on outcomes in rectal cancer.

BACKGROUND AND OBJECTIVES: Preoperative chemoradiotherapy for locally advanced rectal cancer is now considered "standard of care." However, the optimal time interval for resection after neoadjuvant therapy is unknown. METHODS: Between 11/90 and 11/04, 107 patients with rectal adenocarcinoma underwent preoperative chemo/RT at the University of Pennsylvania. Fifty-six percent had LAR and 40% had APR. Chemotherapy consisted of 5-FU/oxaliplatin in 28% and 5-FU in 72% of patients. All patients received preoperative RT. RESULTS: A longer time interval between chemo/RT and surgery was associated with tumor downstaging (OR 1.24, P = 0.02). A longer time interval was not associated with: nodal downstaging (OR 1.00, P = 0.98); pathologic complete response (PCR) (OR 0.97, P = 0.80); likelihood of performing an LAR (OR 0.90, P = 0.47); improved disease free survival (DFS), local control, or distant control (HR 1.05, P = 0.49; HR 1.14, P = 0.22; HR 1.06, P = 0.52, respectively). The PCR rate was 34.5% in the 5-FU/oxaliplatin/radiation group, and 13.7% in the 5-FU/radiation group. If patients with microscopic CR were excluded, then the PCR rate for 5FU/OX was 21.4% and for 5-FU was 12.2%. CONCLUSIONS: Time interval between surgery and chemo/RT appeared to have little effect on PCR or LAR rates. Patients receiving 5 FU/oxaliplatin/RT had a high PCR rate. A prospective randomized trial to test superiority of 5 FU/oxaliplatin is warranted.

A phase II trial of gefitinib with 5-fluorouracil, leucovorin, and irinotecan in patients with colorectal cancer.

Inhibition of epidermal growth factor receptor (EGFR) signalling contributes to the therapy of colorectal cancer. Gefitinib, an oral EGFR tyrosine kinase inhibitor, shows supra-additive growth inhibition with irinotecan and fluoropyrimidines in xenograft models. We designed a study to determine the tolerability and efficacy of gefitinib in combination with irinotecan, infusional 5-fluorouracil (5-FU) and leucovorin (LV), on a 2-week schedule. Among 13 patients with advanced colorectal cancer, 10 required dose reductions of irinotecan and 5-FU because of dehydration, diarrhoea, and neutropenia, seven of whom required hospitalisation, three with neutropenic fever. One patient achieved partial response and seven had disease stabilisation. The combination of this standard chemotherapy regimen with gefitinib is associated with excessive toxicity, suggesting an interaction at a pharmacokinetic or pharmacodynamic level.

Phase I trial of UFT/leucovorin and irinotecan in patients with advanced cancer.

UFT (BMS-200604, Uftoral) is an oral fluoropyrimidine that combines uracil and the 5-fluorouracil (5-FU) prodrug, ftorafur, in a 4:1 molar ratio with single-agent activity in breast and gastrointestinal cancers. In vitro studies have shown that irinotecan downregulates thymidylate synthase (TS) expression in tumour cells, leading to synergy between irinotecan and 5-FU that is maximal when irinotecan is given 24 h prior to 5-FU. Given this observed synergy and the confirmatory clinical activity of combination therapy with 5-FU, leucovorin (LV) and irinotecan, we performed a phase I trial to determine the maximum tolerated doses (MTD) of UFT, LV, and irinotecan. Treatment consisted of irinotecan administered as a 90-min intravenous (i.v.) infusion on day 1 followed by twice daily oral UFT/LV on days 2-15, repeated every 21 days. Initial doses were irinotecan 200 mg/m(2) and UFT 200 mg/m(2)/day, with LV dose fixed at 60 mg/day. 31 patients received a total of 130 cycles of UFT/LV and irinotecan. 3 of 9 patients experienced grade 3/4 diarrhoea at the highest dose level of irinotecan 310 mg/m(2) and UFT 300 mg/m(2)/day. Other toxicities included neutropenia, anaemia, alopecia, nausea/vomiting and fatigue. Further dose escalation was not pursued since this level of toxicity was appropriate for future phase II study. One patient with colorectal cancer experienced a partial response and 9 patients with non-small cell lung, colorectal and gastro-oesophageal junction carcinomas had disease stabilisation lasting 4-26 (median 6) cycles. Methylenetetrahydrofolate reductase (MTHFR) C677T genotype was analysed in peripheral mononuclear cells (PMNs) obtained from 24 patients. 2 patients had the homozygous TT polymorphism and 1 of them had grade 3 diarrhoea at the first dose level. Irinotecan on day 1 followed by a 14-day course of oral UFT/LV beginning on day 2 is well tolerated, and suitable for testing in several tumour types. Doses recommended for further study on this schedule are irinotecan 310 mg/m(2) and UFT 300 mg/m(2)/day, with LV 60 mg/day.

Colon cancer survival is associated with increasing number of lymph nodes analyzed: a secondary survey of intergroup trial INT-0089.

PURPOSE: To determine the relationship, in patients with adenocarcinoma of the colon, between survival and the number of lymph nodes analyzed from surgical specimens. PATIENTS AND METHODS: Intergroup Trial INT-0089 is a mature trial of adjuvant chemotherapy for high-risk patients with stage II and stage III colon cancer. We performed a secondary analysis of this group with overall survival (OS) as the main end point. Cause-specific survival (CSS) and disease-free survival were secondary end points. Rates for these outcome measures were estimated using Kaplan-Meier methodology. Log-rank test was used to compare overall curves, and Cox proportional hazards regression was used to multivariately assess predictors of outcome. RESULTS: The median number of lymph nodes removed at colectomy was 11 (range, one to 87). Of the 3411 assessable patients, 648 had no evidence of lymph node metastasis. Multivariate analyses were performed on the node-positive and node-negative groups separately to ascertain the effect of lymph node removal. Survival decreased with increasing number of lymph node involvement (P =.0001 for all three survival end points). After controlling for the number of nodes involved, survival increased as more nodes were analyzed (P =.0001 for all three end points). Even when no nodes were involved, OS and CSS improved as more lymph nodes were analyzed (P =.0005 and P =.007, respectively). CONCLUSION: The number of lymph nodes analyzed for staging colon cancers is, itself, a prognostic variable on outcome. The impact of this variable is such that it may be an important variable to include in evaluating future trials.

Recent advances in the treatment of gastric cancer.

Gastric cancer is one of the most common cancers in the world. The prognosis of the disease is poor, with only 40% of patients eligible to undergo potentially curative surgery. Even for those patients who undergo a complete resection, the rate of recurrence is very high. Extensive studies of multidisciplinary adjuvant treatment have been conducted seeking to improve the cure rates in the past two decades. The benefit of D2 dissection is still controversial and is undergoing prospective evaluation. Preliminary results from the United States Gastrointestinal Intergroup study, a well designed trial, have shown overall survival benefit of postoperative chemoradiation therapy. Neoadjuvant chemotherapy or chemoradiation is under active study in order to increase the number of patients to undergo potential curative surgery. Although many chemotherapy regimens have been developed recently, only modest clinical efficacy has been demonstrated for advanced metastatic disease. So far, there is no single regimen considered to be standard.

Phase I clinical and pharmacogenetic trial of irinotecan and raltitrexed administered every 21 days to patients with cancer.

PURPOSE: Irinotecan and raltitrexed display schedule-dependent synergy in vitro, which supports the clinical investigation of the combination. Functional polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene result in intracellular redistribution of folate derivatives, which may affect raltitrexed-associated cytotoxicity. PATIENTS AND METHODS: Patients with a range of solid cancers and good performance status received irinotecan as a 90-minute infusion on day 1 and raltitrexed as a 15-minute infusion on day 2, repeated every 21 days. Samples were collected for MTHFR C677T genotyping and fasting plasma homocysteine during the first cycle. RESULTS: Thirty-nine assessable patients received 127 cycles of therapy. Irinotecan doses ranged from 100 to 350 mg/m(2), and raltitrexed, 1.0 to 4.0 mg/m(2). Raltitrexed doses of more than 3.0 mg/m(2) were not tolerated and were associated with dose-limiting asthenia, diarrhea, and AST/ALT elevation. Irinotecan/raltitrexed doses of 350/3.0 mg/m(2) were well-tolerated; principal toxicities included neutropenia, diarrhea, and fatigue. Two partial responses were observed in patients with pretreated gastroesophageal cancers. Homozygotes with the MTHFR 677 TT polymorphism incurred significantly less raltitrexed-associated toxicity than those with either wild-type or heterozygous genotypes (P = .05). No significant differences were noted in plasma homocysteine values between the genotypic subtypes, and plasma homocysteine levels did not predict the risk of toxicity. CONCLUSION: Irinotecan and raltitrexed doses of 350 and 3.0 mg/m(2) are recommended for further study on a day 1, 2 schedule every 21 days. Efficacy results suggest that trials in upper and lower gastrointestinal malignancies are warranted. MTHFR C677T genotypes may be predictive of clinical raltitrexed toxicity.

A pooled analysis of adjuvant chemotherapy for resected colon cancer in elderly patients.

BACKGROUND: Adjuvant chemotherapy is standard treatment for patients with resected colon cancer who are at high risk for recurrence, but the efficacy and toxicity of such treatment in patients more than 70 years of age are controversial. METHODS: We performed a pooled analysis, based on the intention to treat, of individual patient data from seven phase 3 randomized trials (involving 3351 patients) in which the effects of postoperative fluorouracil plus leucovorin (five trials) or fluorouracil plus levamisole (two trials) were compared with the effects of surgery alone in patients with stage II or III colon cancer. The patients were grouped into four age categories of equal size, and analyses were repeated with 10-year age ranges (< or =50, 51 to 60, 61 to 70, and >70 years), with the same conclusions. The toxic effects measured in all trials were nausea or vomiting, diarrhea, stomatitis, and leukopenia. Patients in the fluorouracil-plus-leucovorin and fluorouracil-plus-levamisole groups were combined for the efficacy analysis but kept separate for toxicity analyses. RESULTS: Adjuvant treatment had a significant positive effect on both overall survival and time to tumor recurrence (P<0.001 for each, with hazard ratios of death and recurrence of 0.76 [95 percent confidence interval, 0.68 to 0.85] and 0.68 [95 percent confidence interval, 0.60 to 0.76], respectively). The five-year overall survival was 71 percent for those who received adjuvant therapy, as compared with 64 percent for those untreated. No significant interaction was observed between age and the efficacy of treatment. The incidence of toxic effects was not increased among the elderly (age >70 years), except for leukopenia in one study. CONCLUSIONS: Selected elderly patients with colon cancer can receive the same benefit from fluorouracil-based adjuvant therapy as their younger counterparts, without a significant increase in toxic effects.

Phase II trial of dacarbazine (DTIC) in advanced pancreatic islet cell carcinoma. Study of the Eastern Cooperative Oncology Group-E6282.

BACKGROUND: A phase II study of dacarbazine (DTIC), was conducted to determine the response rate, duration of response, toxicity and overall survival of patients with advanced pancreatic islet cell tumors. PATIENTS AND METHODS: Fifty patients with advanced pancreatic islet cell tumors, having progressive symptoms or evidence of rapidly advancing disease were entered on this study. DTIC was given by IV infusion at a dose of 850 mg/m2, over 60-90 minutes, repeated every four weeks. RESULTS: The response rate was 33% in 42 patients who had measurable tumor, and 34% in the 50 patients (90% confidence interval (90% CI): 23%-47%). The majority of the responses were seen in patients without prior chemotherapy. Median overall survival was 19.3 months. There were two lethal toxicities on the study, one septic shock and one myocardial infarction. Grade 4 toxicities were, hematological (5 patients), sepsis, neurological (depression and paranoid behavior) and bleeding (1 patient each). The most common toxicity was vomiting, grade 3 in 13% of patients. CONCLUSIONS: DTIC has activity in advanced previously untreated pancreatic islet cell tumors.

Chemoradiotherapy after surgery compared with surgery alone for adenocarcinoma of the stomach or gastroesophageal junction.

BACKGROUND: Surgical resection of adenocarcinoma of the stomach is curative in less than 40 percent of cases. We investigated the effect of surgery plus postoperative (adjuvant) chemoradiotherapy on the survival of patients with resectable adenocarcinoma of the stomach or gastroesophageal junction. METHODS: A total of 556 patients with resected adenocarcinoma of the stomach or gastroesophageal junction were randomly assigned to surgery plus postoperative chemoradiotherapy or surgery alone. The adjuvant treatment consisted of 425 mg of fluorouracil per square meter of body-surface area per day, plus 20 mg of leucovorin per square meter per day, for five days, followed by 4500 cGy of radiation at 180 cGy per day, given five days per week for five weeks, with modified doses of fluorouracil and leucovorin on the first four and the last three days of radiotherapy. One month after the completion of radiotherapy, two five-day cycles of fluorouracil (425 mg per square meter per day) plus leucovorin (20 mg per square meter per day) were given one month apart. RESULTS: The median overall survival in the surgery-only group was 27 months, as compared with 36 months in the chemoradiotherapy group; the hazard ratio for death was 1.35 (95 percent confidence interval, 1.09 to 1.66; P=0.005). The hazard ratio for relapse was 1.52 (95 percent confidence interval, 1.23 to 1.86; P<0.001). Three patients (1 percent) died from toxic effects of the chemoradiotherapy; grade 3 toxic effects occurred in 41 percent of the patients in the chemoradiotherapy group, and grade 4 toxic effects occurred in 32 percent. CONCLUSIONS: Postoperative chemoradiotherapy should be considered for all patients at high risk for recurrence of adenocarcinoma of the stomach or gastroesophageal junction who have undergone curative resection.

Long term survival after pancreatic resection for pancreatic adenocarcinoma.

OBJECTIVE: The aim of this study was to determine the long term survival of patients with pancreatic adenocarcinoma who underwent surgical resection and to assess the association of clinical, pathological, and treatment features with survival. METHODS: Between January, 1990, and December, 1998, 125 patients underwent a pancreaticoduodenal or partial pancreatic resection for pancreatic ductal adenocarcinoma at our institution. The records of these patients were reviewed for demographics, tumor characteristics including size, histological grade, margin status, lymph node status, surgical TNM staging, and postoperative adjuvant therapy. The primary outcome variable analyzed was survival. RESULTS: A total of 116 patients had complete follow-up and were included in the final analysis. The median survival after surgery was 16 months. The 1-, 3-, 5-, and 7-yr survival rates for all 116 patients were 60%, 23%, 19%, and 11%, respectively. The 1-, 3-, 5-, and 7-yr survival rates for patients who received adjuvant therapy were 69%, 28%, 23%, and 18% compared with 20% and 0% in patients who did not receive adjuvant therapy (p < 0.0001). The 1-, 3-, 5-, and 7-yr survival rates for patients with negative lymph nodes were 73%, 38%, 26%, and 22% compared with survival rates of 52%, 14%, 14%, and 9% in patients with positive lymph nodes (p = 0.01). In multivariate analyses, adjuvant therapy was the only feature found to be strongly associated with survival (hazards ratio = 0.26, 95% CI = 0.15-0.44). CONCLUSIONS: The overall 5- and 7-yr survival rates of 19% and 11% in our study further validate that surgical resection in patients with pancreatic adenocarcinoma can result in long term survival, particularly when performed in association with adjuvant chemoradiation.

Fluorouracil modulation in colorectal cancer: lack of improvement with N -phosphonoacetyl- l -aspartic acid or oral leucovorin or interferon, but enhanced therapeutic index with weekly 24-hour infusion schedule--an Eastern Cooperative Oncology Group/Cancer and Leukemia Group B Study.

PURPOSE: To investigate mechanism-directed regimens in maximizing the efficacy of fluorouracil (5-FU) in advanced colorected cancer. PATIENTS AND METHODS: Based on promising phase II data, a randomized comparison of various methods for the biochemical modulation of 5-FU was undertaken in patients with advanced colorectal cancer. The control group received single-agent 5-FU as a 24-hour infusion weekly. Patients (N = 1,120) with no prior chemotherapy for metastatic disease were randomized to one of the following arms: arm A, 5-FU 2,600 mg/m2 by 24-hour infusion, weekly; arm B, N-phosphonoacetyl-l-aspartic acid 250 mg/m2 day l, 5-FU 2,600 mg/m2 by 24-hour infusion day 2, weekly; arm C, 5-FU 600 mg/m2 with oral leucovorin (LV) 125 mg/m2 hourly for the preceding 4 hours, weekly; arm D, 5-FU 600 mg/m2 with intravenous (IV) LV 600 mg/m2, weekly; arm E, 5-FU 750 mg/m2/d IV by continuous infusion for 5 days, then 750 mg/m2 weekly, and recombinant interferon alfa-2a 9 million units subcutaneously three times weekly. Median follow-up was 4.8 years. RESULTS: Of the 1,098 assessable patients, 57% had measurable disease. The toxicity of all the regimens was tolerable. Grade 4 or worse toxicity occurred in 11%, 11%, 30%, 24%, and 22% on each arm, respectively; diarrhea was the most common adverse effect. These toxicity patterns favored significantly (P <.001) the 24-hour infusion arms. Median survival (months) by arm was A, 14.8; B, 11.9; C, 13.5; D, 13.6; and E, 15.2. These survival durations did not differ significantly. CONCLUSION: We conclude that a weekly infusion regimen of 5-FU is significantly less toxic than and as effective as 5-FU bolus regimens modulated by either LV or interferon in patients with metastatic colorectal cancer.

Molecular predictors of survival after adjuvant chemotherapy for colon cancer.

BACKGROUND: Adjuvant chemotherapy improves survival among patients with stage III colon cancer, but no reliable molecular predictors of outcome have been identified. METHODS: We evaluated loss of chromosomal material (also called loss of heterozygosity or allelic loss) from chromosomes 18q, 17p, and 8p; cellular levels of p53 and p21(WAF1/CIP1) proteins; and microsatellite instability as molecular markers. We analyzed tumor tissue from 460 patients with stage III and high-risk stage II colon cancer who had been treated with various combinations of adjuvant fluorouracil, leucovorin, and levamisole to determine the ability of these markers to predict survival. RESULTS: Loss of heterozygosity at 18q was present in 155 of 319 cancers (49 percent). High levels of microsatellite instability were found in 62 of 298 tumors (21 percent), and 38 of these 62 tumors (61 percent) had a mutation of the gene for the type II receptor for transforming growth factor beta1 (TGF-beta1). Among patients with microsatellite-stable stage III cancer, five-year overall survival after fluorouracil-based chemotherapy was 74 percent in those whose cancer retained 18q alleles and 50 percent in those with loss of 18q alleles (relative risk of death with loss at 18q, 2.75; 95 percent confidence interval, 1.34 to 5.65; P=0.006). The five-year survival rate among patients whose cancer had high levels of microsatellite instability was 74 percent in the presence of a mutated gene for the type II receptor for TGF-beta1 and 46 percent if the tumor did not have this mutation (relative risk of death, 2.90; 95 percent confidence interval, 1.14 to 7.35; P=0.03). CONCLUSIONS: Retention of 18q alleles in microsatellite-stable cancers and mutation of the gene for the type II receptor for TGF-beta1 in cancers with high levels of microsatellite instability point to a favorable outcome after adjuvant chemotherapy with fluorouracil-based regimens for stage III colon cancer.

Update on chemotherapy for advanced colorectal cancer.

Efforts to improve the length and quality of life, as well as to expand treatment options, for patients with metastatic colorectal cancer have only recently become more successful. With maximization of dose and schedule schemes for fluoropyrimidine therapy, new drugs such as irinotecan (CPT-11, Camptosar) and oxaliplatin have also become part of the standard therapy for patients. Combination chemotherapy has been established to have superior response rates and progression-free survival and--in some instances, for fluorouracil and irinotecan combinations--improved overall survival compared to fluorouracil alone. There is still much to be learned about the optimal management of patients with colorectal cancer, including the role of second- and third-line chemotherapy in the overall survival outcome, and the role of salvage therapy in patients with limited metastatic disease. Most importantly, the development of a biological marker of prognosis and response should help to select appropriate chemotherapy programs for patients on a rational and individual basis, not only in the setting of metastatic disease, but also in the adjuvant population.

Update of clinical trials with edrecolomab: a monoclonal antibody therapy for colorectal cancer.

Edrecolomab is a murine IgG2a monoclonal antibody that recognizes the tumor-associated antigen Ep-CAM. Its antitumor effects are mediated through antibody-dependent cellular cytotoxicity, complement-mediated cytolysis, and the induction of an anti-idiotypic network. An initial study of 189 patients with resected stage III colorectal cancer showed that edrecolomab reduced the relative risk of mortality by 32% compared with observation alone (P < .01). Edrecolomab has now been investigated in two large phase III studies of patients with stage III colon cancer, either as a single agent or in combination with 5-FU-based chemotherapy. Preliminary safety data have shown that edrecolomab is well tolerated when used as monotherapy and adds little to chemotherapy-related side effects when used in combination. Edrecolomab is also being studied as monotherapy following resection of stage II colon cancer, and in combination with chemotherapy in patients with resected stage II or III rectal cancer. In conclusion, edrecolomab is a novel biological therapy for the adjuvant treatment of colorectal cancer. Completed and ongoing trials may support its use as monotherapy in stage II colon cancer or in combination with chemotherapy in stage III colon cancer and stage II/III rectal cancer.

Follow-up of stage B and C colorectal cancer in the United States and France.

The optimal postoperative follow-up strategy for patients with resected Dukes' Stage B and C colorectal cancer is controversial. Recently published guidelines support a minimal regimen of carcinoembryonic antigen measurements every 2 to 3 months for at least 2 years, history and physical examination every 3 to 6 months for 3 years, then annually, and colonoscopy every 3 to 5 years. Based on documented practice on the part of surgeons, this regimen would be regarded as intensive. Analyses of relapses following adjuvant therapy support an even more aggressive schedule, with the goal of maximizing the proportion of patients who may be operated on with curative intent (currently about 20% of those who relapse). Additional considerations that may influence the approach to such patients include the identification of second primary tumors (2% over 7 years observation), and the known improvement in quality of life and survival associated with early versus delayed initiation of chemotherapy. However, with the annual investment of resources estimated to be as high as 175 million dollars in the United States alone, a systematic study of such interventions is needed to provide support survival, quality of life, and economic evidence.