Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial.

BACKGROUND: Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease. PATIENTS AND METHODS: Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone. RESULTS: HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation. CONCLUSION: Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS. CLINICAL TRIAL: INT-0116/SWOG9008 phase III.

An assessment of the carcinogenic potential of ezetimibe using nonclinical data in a weight-of-evidence approach.

Ezetimibe blocks intestinal absorption of sterols via interaction with the Neimann-Pick C1-Like 1 (NPC1L1) transporter and is approved for use in the treatment of primary hyperlipidemia (heterozygous familial and non-familial), homozygous familial hypercholesterolemia, and homozygous sitosterolemia. A recently completed randomized clinical trial [simvastatin and ezetimibe in aortic stenosis (SEAS)] testing the effectiveness of Vytorin (a combination of simvastatin and ezetimibe) in patients with aortic stenosis reported an unexpected safety finding: an increase in overall cancer incidence and cancer-associated mortality (all types) in the treated groups relative to the placebo control. A subsequent meta-analysis utilizing a much larger database from two ongoing clinical trials indicated that the observed findings in the SEAS trial were likely due to chance and not a true drug-induced effect. Nonetheless, it has been suggested by various commentators on the SEAS trial that ezetimibe may be carcinogenic. The extensive nonclinical database for ezetimibe was used to test the hypothesis that ezetimibe may be a direct or indirect carcinogen. Using two different in silico approaches, ezetimibe showed no structural alerts for genetic toxicity or carcinogenicity. Ezetimibe was not genotoxic in two reverse mutation assays, one in vitro clastogenicity assay, and two mouse micronucleus assays. No evidence of proliferative lesions was observed in three species in studies of 1-12 months in duration. Ezetimibe was not carcinogenic in standard 2-year bioassays in mice and rats. Additionally, in these 2-year bioassays, no drug-related non-neoplastic lesions were noted. The absence of drug-induced non-neoplastic or proliferative lesions in these studies indicates that ezetimibe treatment was not associated with findings characteristic of carcinogens (i.e., DNA reactivity or cell proliferation) Administration of pharmacologic doses of ezetimibe to mice did not alter hepatic expression patterns of genes associated with apoptosis, cell proliferation, or epithelial-mesenchymal transition. No evidence of drug-induced tumors was observed in mice in which the molecular target of ezetimibe (NPC 1L1) was knocked out over the life span of the animal. In conclusion, the nonclinical data do not support the proposed hypothesis based on the single observation from the SEAS trial and, rather, support the conclusion that ezetimibe does not represent a carcinogenic hazard to humans using this drug in a therapeutic setting.

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.

Phase II trial of 5-fluorouracil plus eniluracil in patients with advanced pancreatic cancer: a Southwest Oncology Group study.

BACKGROUND: Eniluracil is a potent, irreversible inactivator of dihydropyrimidine dehydrogenase, the major catabolic enzyme for 5-fluorouracil (5-FU). Pretreatment with eniluracil significantly increases plasma half-life, plasma concentration and oral bioavailability of 5-FU. This multicenter phase II trial was designed to estimate the 6-month survival rate in patients with metastatic adenocarcinoma of the pancreas treated with 5-FU and eniluracil. PATIENTS AND METHODS: One hundred and sixteen patients (61 with no prior chemotherapy and 55 with prior chemotherapy) were registered for treatment with eniluracil 50 mg (total dose) p.o. on days 1-7 and 5-FU 20 mg/m(2)/day p.o. on days 2-6 of a 28-day treatment cycle. RESULTS: In 106 patients evaluable for survival, the 6-month survival rate was 34% [95% confidence interval (CI) 22% to 47%, median survival 3.6 months] for patients who had not been treated previously with chemotherapy and 29% (95% CI 16% to 42%, median survival 3.4 months) for those who had received prior chemotherapy. For those patients with measurable disease, the confirmed response rates were 8% and 2%, respectively. The most common grade 3-4 toxicities were neutropenia (29% of patients) and diarrhea (12% of patients). Overall, 69% of patients experienced a grade 3 or worse adverse event during treatment. CONCLUSIONS: These results suggest that the combination of a 7-day course of eniluracil and a 5-day course of oral 5-FU has limited activity in patients with advanced pancreatic cancer, and is associated with a high frequency of clinically significant adverse events.

Adjuvant therapy in rectal cancer: analysis of stage, sex, and local control--final report of intergroup 0114.

PURPOSE: The gastrointestinal Intergroup studied postoperative adjuvant chemotherapy and radiation therapy in patients with T3/4 and N+ rectal cancer after potentially curative surgery to try to improve chemotherapy and to determine the risk of systemic and local failure. PATIENTS AND METHODS: All patients had a potentially curative surgical resection and were treated with two cycles of chemotherapy followed by chemoradiation therapy and two additional cycles of chemotherapy. Chemotherapy regimens were bolus fluorouracil (5-FU), 5-FU and leucovorin, 5-FU and levamisole, and 5-FU, leucovorin, and levamisole. Pelvic irradiation was given to a dose of 45 Gy to the whole pelvis and a boost to 50.4 to 54 Gy. RESULTS: One thousand six hundred ninety-five patients were entered and fully assessable, with a median follow-up of 7.4 years. There was no difference in overall survival (OS) or disease-free survival (DFS) by drug regimen. DFS and OS decreased between years 5 and 7 (from 54% to 50% and 64% to 56%, respectively), although recurrence-free rates had only a small decrease. The local recurrence rate was 14% (9% in low-risk [T1 to N2+] and 18% in high-risk patients [T3N+, T4N]). Overall, 7-year survival rates were 70% and 45% for the low-risk and high-risk groups, respectively. Males had a poorer overall survival rate than females. CONCLUSION: There is no advantage to leucovorin- or levamisole-containing regimens over bolus 5-FU alone in the adjuvant treatment of rectal cancer when combined with irradiation. Local and distant recurrence rates are still high, especially in T3N+ and T4 patients, even with full adjuvant chemoradiation therapy.

Background and framework for ILSI's collaborative evaluation program on alternative models for carcinogenicity assessment. International Life Sciences Institute.

The willingness of the agencies involved in the regulation of pharmaceuticals to accept data from newly proposed models for carcinogenicity testing (eg, transgenic animals, neonatal rodent models, initiation-promotion models) has stimulated international interest in gaining experience and a greater understanding of the strengths and limitations of the specific models. Over a 4-year period, the International Life Sciences Institute (ILSI) Health and Environmental Science Institute (HESI) has coordinated a large-scale collaborative research program to help to better characterize the responsiveness of several models proposed for use in carcinogenicity assessment. The overall objective of this partnership among industry, government, and academic scientists was to evaluate the ability of these new models to provide useful information for human cancer risk assessment. This research program reflected a commitment of nearly US$35 million by over 50 industrial, govemment, and academic laboratories from the United States, Europe, and Japan. Evaluation of the models required the development of standardized protocols to allow reproducibility and comparability of data obtained across multiple laboratories. Test compounds were selected on the basis of mechanistically meaningful carcinogenic activity or noncarcinogenicity in the rodent bioassay as well as humans. Criteria were established for dose selection, pathology review, quality control, and for evaluation of study outcome. The database from these studies represents an important contribution to the future application of new models for human cancer risk assessment. Beyond the data, the collaborative process by which the models were evaluated may also represent a prototype for assessing new methods in the future.

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.

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.

Adjuvant therapy of colon cancer.

The primary curative therapy of colorectal cancer is surgical resection. However, within the last 15 years, prospectively randomized appropriately powered clinical trials have convincingly demonstrated that adjunctive postoperative adjuvant chemotherapy is of benefit to all patients with node-positive disease (stage III) and arguably to high-risk node-negative (stage II) cases. In the United States, the clinical trials encompassing greater than 5,000 cases have demonstrated that fluorouracil (5-FU)/leucovorin used in a variety of doses and schedules improves disease-free and overall survival in resected node-positive (stage III) colorectal cancer. The postoperative use of 5-FU/leucovorin for approximately 6 months represents standard of care for such patients. Current clinical trials are evaluating the role of nonfluorinated pyrimidine chemotherapeutic agents in adjuvant chemotherapy for resected large bowel cancer. 5-FU/leucovorin combined with irinotecan (CPT-11) versus 5-FU/leucovorin are being tested in a national intergroup clinical trial. Another trial is evaluating 5-FU/leucovorin plus oxaliplatin versus 5-FU/leucovorin alone. These clinical trials will be important in defining the appropriate standard of care for patients with resected colorectal cancer, since recent studies in advanced colorectal cancer in the United States and in Western Europe have demonstrated that combinations of 5-FU/leucovorin and CPT-11 or 5-FU/ leucovorin and oxaliplatin are superior to 5-FU/leucovorin alone.

Impact of number of nodes retrieved on outcome in patients with rectal cancer.

PURPOSE: We postulated that the pathologic evaluation of the lymph nodes of surgical specimens from patients with rectal cancer can have a substantial impact on time to relapse and survival. PATIENTS AND METHODS: We analyzed data from 1,664 patients with T3, T4, or node-positive rectal cancer treated in a national intergroup trial of adjuvant therapy with chemotherapy and radiation therapy. Associations between the number of lymph nodes found by the pathologist in the surgical specimen and the time to relapse and survival outcomes were investigated. RESULTS: Patients were divided into groups by nodal status and the corresponding quartiles of numbers of nodes examined. The number of nodes examined was significantly associated with time to relapse and survival among patients who were node-negative. For the first through fourth quartiles, the 5-year relapse rates were 0.37, 0.34, 0.26, and 0.19 (P: = .003), and the 5-year survival rates were 0.68, 0.73, 0.72, and 0.82 (P: = .02). No significant differences were found by quartiles among patients determined to be node-positive. We propose that observed differences are primarily related to the incorrect determination of nodal status in node-negative patients. Approximately 14 nodes need to be studied to define nodal status accurately. CONCLUSION: These results suggest that the pathologic assessment of lymph nodes in surgical specimens is often inaccurate and that examining greater number of nodes increases the likelihood of proper staging. Some patients who might benefit from adjuvant therapy are misclassified as node-negative due to incomplete sampling of lymph nodes.

A phase II trial of etoposide, leucovorin, 5-FU, and interferon alpha 2b (ELFI) + G-CSF for patients with pancreatic adenocarcinoma: a Southwest Oncology Group study (SWOG 9413).

BACKGROUND: Chemotherapeutic treatments using combinations of etoposide, leucovorin and 5-FU (ELF) have shown activity in the treatment of gastrointestinal malignancies. Interferon alpha 2b is known to have antiproliferative effects on several cell lines and has well documented in vitro evidence of synergism with 5-FU. It was postulated that the combination of ELF and interferon alpha 2b would improve response rates and survival in patients with pancreas cancer. METHODS: Fifty-five eligible patients with locally-advanced or metastatic pancreatic adenocarcinoma received a regimen consisting of: i.v. leucovorin at 300 mg/m2/day on Days 1-3 (of 28-day cycle), i.v. etoposide at 80 mg/m2/day on Days 1-3, i.v. 5-FU at 500 mg/m2/day on Days 1-3, subcutaneous interferon alpha 2b at 3 million units TIW, and subcutaneous G-CSF at 5 microg/kg/day on Days 4-14 (or until WBC exceeds 10,000/microl). Patients with no evidence of disease progression continued on treatment for a total of 6 cycles. RESULTS: Complete response was demonstrated in 1 patient, partial response in 5 patients (11% confirmed response rate). The median survival was 5 months, and the six-month survival rate was 40%. Ten patients completed all 6 cycles of treatment. Toxicity-related dose delays and reductions were necessary for most patients. CONCLUSIONS: Although the combination of ELF and interferon alpha 2b (ELFI) has modest activity in pancreatic cancer, it is a toxic and complex regimen that is not superior to other currently available approaches for the chemotherapeutic management of pancreatic cancer. ELFI cannot be recommended as a standard therapy.

A phase II trial of topotecan in esophageal carcinoma: a Southwest Oncology Group study (SWOG 9339).

BACKGROUND: Chemotherapeutic treatments containing topoisomerase I inhibitors have shown antitumor activity against a number of solid tumors. Responses have been seen in Phase I trials using topotecan in ovarian, lung, and esophageal cancer. A phase II trial using continuous infusion topotecan was completed to assess activity in esophagus cancer. METHODS: Forty-five eligible patients with locally-advanced or metastatic squamous cell carcinoma or adenocarcinoma of the esophagus received a regimen consisting of 24-hour continuous infusion topotecan at 1.5 mg/m2/day on Days 1, 8, 15, 22 (of 42-day cycle). Patients continued on treatment until evidence of disease progression or unacceptable toxicity. RESULTS: Partial response was demonstrated in 1 patient (2% confirmed response rate). Thirty-six patients progressed during the first cycle of treatment. The median survival was 3 months, and the median progression-free survival was 1 month. Toxicity was mild with only one Grade 4 toxicity reported. CONCLUSIONS: This phase II trial indicates no significant anti-neoplastic activity for topotecan administered in the dose and schedule to patients with squamous cell or adenocarcinoma of the esophagus.

Association of immune parameters with clinical outcome in stage III colon cancer: results of Southwest Oncology Group Protocol 9009.

Levamisole (LMS), utilized in the adjuvant treatment of patients with stage III colon cancer, is immunomodulatory. To determine whether alterations in immune parameters before, during and after 12 months of 5FU/LMS therapy correlate with disease-free survival, 38 patients enrolled on Southwest Oncology Group (SWOG) protocol 8899 received extensive lymphocyte phenotypic analysis prior to therapy and 3, 6, 12 and 15 months after treatment initiation. The median follow-up of patients is 41 months. Significant increases in the proportion and total number of CD56+ natural killer cells were seen, starting at 3 months and continuing until 15 months (P < 0. 001). Increases in the total numbers of cells expressing CD25 (interleukin-2 receptor), VLA4 and the combinations of CD4: CD45RA and CD4:CDw29 were not evident during therapy but were seen at 15 months (P < 0.05: CD25, CD4:CDw29, CD4:CD45RA; P < 0.001: VLA4). Low levels of CD8+ cells prior to treatment initiation and after 3 months of therapy correlated with early relapse within the first year of 5FU/LMS treatment. Patients who have remained disease-free (n = 22, median follow-up 45 months) demonstrated increases in the total numbers of CD8+, CD25+, CD56+, VLA4+, CD4: CDw29 and CD4:CD45RA cells, primarily at 15 months. In contrast, patients who relapsed had decreased numbers of CD8+, CD4:CDw29, CD4: CD45RA and VLA4+ cells and minimal increases in CD56+ and CD25+ cells. Statistically significant differences between the late-relapse group and the group remaining disease-free were seen for CD25+, CD4: CD45RA and CD4:CDw29 cells at the 15-month assay time (P = 0.0276, P = 0.0349, P = 0.0178 respectively). In conclusion, multiple alterations in lymphocyte phenotype, with increases in the proportion and total number of cells involved in cell-mediated immune responses, were seen during and especially following completion of therapy with 5FU/LMS. Many of these changes are significantly associated with clinical outcome and may be useful for risk stratification of stage III colon cancer patients following completion of adjuvant therapy.

Oral fluoropyrimidines: a closer look at their toxicities.

Patient preferences, quality of life issues, and economic considerations are driving the development of orally administered chemotherapy. Oral fluorinated pyrimidines, which have been used in Japan, are attracting increasing interest as a means to provide convenient, less toxic treatment without compromising efficacy. The oral fluoropyrimidines provide prolonged 5-fluorouracil (5-FU) exposure at lower peak concentrations than those observed with bolus intravenous administration. Moreover, depending on the dose schedule, the pharmacokinetics of the oral fluoropyrimidines may mimic the pharmacokinetics of continuous-infusion 5-FU. This review focuses on the toxicity profiles of five emerging oral fluoropyrimidine antineoplastic drugs: combined uracil and tegafur (UFT), capecitabine, eniluracil, S-1, and emitefur (BOF-A2). Different patterns of toxicities emerge from an analysis of the clinical trials of these agents relative to 5-FU administered as an intermittent intravenous bolus or as continuous infusion. The results of ongoing phase III trials comparing the oral fluoropyrimidines with conventional regimens of 5-FU plus leucovorin and 5-FU by continuous intravenous infusion are necessary before their therapeutic role in the management of colorectal carcinoma can be defined.

Carcinoembryonic antigen screening: pros and cons.

The appropriate use of plasma carcinoembryonic antigen (CEA) levels in the management of patients with colorectal cancer has been debated over the last 30 years. It is clear from the very low sensitivity of this test in normal populations that there is no role for CEA assessment as a screening tool for colon cancer. Although in patients receiving chemotherapy for metastatic colon cancer, elevations of CEA generally indicate disease progression, while decreases are indicative of improvement, there is no convincing evidence that CEA monitoring significantly affects either survival or quality of life. The area of most interest for CEA monitoring has been the potential for its use after curative resection. The purpose of postoperative CEA monitoring would be to detect recurrence of cancer at an early, surgically curable stage. There is good evidence that routine CEA monitoring postresection of colon cancer detects metastatic disease on average 5 months before routine follow-up evaluation without CEA monitoring detects recurrence. Also, studies demonstrate that some patients with recurrent cancer detected by CEA monitoring may be cured by surgical resection of metastases. However, the overall cost-effectiveness of this approach is not clear, and convincing definition of the role of postoperative CEA monitoring awaits the results of large randomized clinical trials.

Hepatic chemoembolization combined with systemic infusion of 5-fluorouracil and bolus leucovorin for patients with metastatic colorectal carcinoma: A Southwest Oncology Group pilot trial.

BACKGROUND: Rates of response to systemic chemotherapy among patients with advanced colorectal carcinoma rarely exceed 25- 30%, and complete responses are rare. The liver is the most common site of metastasis; however, regional therapies have not improved survival rates. The Southwest Oncology Group designed a clinical trial combining hepatic arterial chemoembolization with systemic infusion of 5-fluorouracil chemotherapy in an attempt to increase the complete response rate and prolong the time to disease progression. METHODS: Patients with documented liver metastasis from colorectal carcinoma were treated with two or three cycles of chemoembolization using a collagen suspension with doxorubicin, mitomycin C, and cisplatin. Subsequently, systemic chemotherapy with continuous infusion of 5-fluorouracil and weekly leucovorin was initiated. Patients were assessed for response at 12-week intervals, with treatment continuing until disease progression. RESULTS: Thirty-one eligible, evaluable patients were treated. One complete and 8 partial responses were observed, for an overall response rate of 29%. Fifty-eight percent of patients survived 1 year, and the median survival for the whole cohort was 14 months. The median time to progression was 8 months. Seven patients (23%) experienced Grade 4 toxicity and 21 patients (67%) had Grade 3 toxicity. CONCLUSIONS: The response rate in this trial was comparable to that achieved with systemic chemotherapy consisting of a fluorinated pyrimidine-based regimen for patients with this disease. No improvement in complete response rate or time to progression was observed compared with the Southwest Oncology Group's experience with systemic therapy. The authors are not planning to study this regimen further as a treatment for patients with metastatic colorectal carcinoma.

Toxicity of 5-fluorouracil.

Fluorouracil (5-FU) is a relatively unique drug in oncology because administration in different doses and schedules results in dramatically different patterns of qualitative toxicity. In the 41 years 5-FU has been available to the clinical oncologist, a wide variety of doses and schedules of this agent have been used. Infusional schedules are associated with less myelosuppression but may have more gastrointestinal and skin toxicity. Bolus schedules cause myelotoxicity, and bolus schedules including calcium folinate are associated with diarrhea, mucositis, and, in some schedules, myelosuppression. The availability of various doses and schedules of 5-FU for administration allows clinicians to choose a 5-FU regimen with the most acceptable pattern of toxicity for individual cases. Also, the study of 5-FU in various groups of patients has demonstrated that relatively increased drug toxicity may be expected in patients above the age of 70 years and in female patients.

Chemoradiotherapy of locally advanced esophageal cancer: long-term follow-up of a prospective randomized trial (RTOG 85-01). Radiation Therapy Oncology Group.

CONTEXT: Carcinoma of the esophagus traditionally has been treated by surgery or radiation therapy (RT), but 5-year overall survival rates have been only 5% to 10%. We previously reported results of a study conducted from January 1986 to April 1990 of combined chemotherapy and RT vs RT alone when an interim analysis revealed significant benefit for combined therapy. OBJECTIVE: To report the long-term outcomes of a previously reported trial designed to determine if adding chemotherapy during RT improves the survival rate of patients with esophageal carcinoma. DESIGN: Randomized controlled trial conducted 1985 to 1990 with follow-up of at least 5 years, followed by a prospective cohort study conducted between May 1990 and April 1991. SETTING: Multi-institution participation, ranging from tertiary academic referral centers to general community practices. PATIENTS: Patients had squamous cell or adenocarcinoma of the esophagus, T1-3 N0-1 M0, adequate renal and bone marrow reserve, and a Karnofsky score of at least 50. Interventions Combined modality therapy (n = 134): 50 Gy in 25 fractions over 5 weeks, plus cisplatin intravenously on the first day of weeks 1, 5, 8, and 11, and fluorouracil, 1 g/m2 per day by continuous infusion on the first 4 days of weeks 1, 5, 8, and 11. In the randomized study, combined therapy was compared with RT only (n = 62): 64 Gy in 32 fractions over 6.4 weeks. MAIN OUTCOME MEASURES: Overall survival, patterns of failure, and toxic effects. RESULTS: Combined therapy significantly increased overall survival compared with RT alone. In the randomized part of the trial, at 5 years of follow-up the overall survival for combined therapy was 26% (95% confidence interval [CI], 15%-37%) compared with 0% following RT. In the succeeding nonrandomized part, combined therapy produced a 5-year overall survival of 14% (95% CI, 6%-23%). Persistence of disease (despite therapy) was the most common mode of treatment failure; however, it was less common in the groups receiving combined therapy (34/130 [26%]) than in the group treated with RT only (23/62 [37%]). Severe acute toxic effects also were greater in the combined therapy groups. There were no significant differences in severe late toxic effects between the groups. However, chemotherapy could be administered as planned in only 89 (68%) of 130 patients (10% had life-threatening toxic effects with combined therapy vs 2% in the RT only group). CONCLUSION: Combined therapy increases the survival of patients who have squamous cell or adenocarcinoma of the esophagus, T1-3 N0-1 M0, compared with RT alone.

A multicenter, phase II trial of weekly irinotecan (CPT-11) in patients with previously treated colorectal carcinoma.

BACKGROUND: This multicenter, Phase II trial was performed to evaluate the antitumor activity and toxicity of irinotecan (CPT-11) in patients with metastatic colorectal carcinoma that had recurred or progressed after 5-fluorouracil (5-FU)-based chemotherapy. METHODS: CPT-11 was given as a 90-minute intravenous infusion in repeated 6-week (42-day) courses comprising weekly treatment for 4 consecutive weeks followed by a 2-week rest. Tumor measurements were obtained after every second course of therapy. Toxicity was assessed weekly using the National Cancer Institute Common Toxicity Criteria. RESULTS: A total of 166 patients were entered into the trial. The first 64 patients received a starting dose of 125 mg/m2. An additional 102 patients were enrolled at a starting dose of 100 mg/m2 to determine whether a reduction in the starting dose would result in lower toxicity without sacrificing efficacy. Objective responses to CPT-11 were observed in 18 patients (1 complete response and 17 partial responses) (response rate [RR] = 10.8%; 95% confidence interval [CI], 6.1-15.6%). An additional 67 patients (40.4%) had stable disease as their best response. At the 125 mg/m2 starting dose, the RR was 14.1% (9 of 64 patients; 95% CI, 5.5-22.6%). Among patients given a starting dose of 100 mg/m2, the RR was 8.8% (9 of 102 patients; 95% CI, 3.3-14.3%). The overall median survival was 9.9 months (range, 0.3-36.8 months). The most frequently observed Grade 3/4 toxicities were gastrointestinal events (i.e., diarrhea [27.1%], nausea [15.1%], emesis [9.6%], abdominal cramping [22.2%], and neutropenia [19.9%]). There were no significant differences in the frequencies of Grade 3/4 toxicities between the 125 mg/m2 and 100 mg/m2 starting dose levels except for Grade 3/4 emesis (21.9% vs. 2%; P < 0.001). Patients age > or = 65 years were twice as likely (38.6% vs. 18.8%; P < 0.008) to develop Grade 3/4 diarrhea compared with younger patients when all courses of therapy were evaluated. However, older age did not significantly predict for a higher incidence of first-course diarrhea (25.0% vs. 14.7%; P = 0.106). CONCLUSIONS: CPT-11 can induce tumor regression in patients with metastatic colorectal carcinoma that has progressed during or shortly after 5-FU-based chemotherapy. Gastrointestinal events and neutropenia were the most common serious toxicities. Given the trend toward a higher response rate without substantially greater toxicity, 125 mg/m2 has been selected as the preferred starting dose for further studies. Careful attention to appropriate CPT-11 dose modification and early intervention with loperamide may be especially important in elderly patients.

p53 immunoreactivity and single-strand conformational polymorphism analysis often fail to predict p53 mutational status.

The intent of this study was to investigate the ability of p53 expression and single-strand conformational polymorphism analysis (SSCP) to predict p53 mutational status in archival, paraffin-embedded tissues of gastric cancer. We evaluated paraffin-embedded tissues from 78 patients with advanced gastric cancer. The mutational status of the p53 gene (exons 5-9) was examined by SSCP analysis and by direct sequencing. These results were compared with p53 expression as assessed by immunohistochemical analysis (IHC). We graded p53 expression on a scale from 0 to 8 on the basis of both the intensity and the number of cells staining. Overall, we detected p53 immunoreactivity in 75.6% of the gastric cases; 19 (32.2%) of these cases scored from 1 to 4, and 40 (67.8%) cases scored from 5 to 8. p53 gene mutations were detected in 18 cases (23.1%) by SSCP and in 28 cases (36%) by direct sequencing. Thus, SSCP failed to detect 38% of the mutations found by sequencing. The majority of missed mutations involved exons 7 and 8. The concordance between IHC and SSCP was 37%, and the concordance between IHC and direct sequencing was 50%. Forty-five percent of cases positive by IHC failed to show mutations in exons 5 through 9. Five percent of cases negative by IHC (4 cases) contained mutations. One had a 1-base pair insertion; one had a mutation that resulted in a stop codon; the third had a mutation in exon 8; and the fourth had a mutation in both exons 5 and 8. Our findings indicate that p53 immunoreactivity correlates with the presence or absence of gene mutations in 50% of advanced gastric cancers when exons 5 through 9 are examined and that IHC cannot be reproducibly used as a marker of mutation in the most commonly mutated exons of the p53 gene. Furthermore, the sensitivity of SSCP for detecting mutations is only 62%. Thus, SSCP analysis cannot be used reliably to screen for p53 mutations.