The role of adjuvant chemotherapy in the treatment of colorectal cancer

Monthly 5-days 5-fluorouracil and low-dose leucovorin for adjuvant chemotherapy in colon cancer

We investigated the dose-related effect of the 5-fluorouracil (5-FU)/leucovorin regimen on survival in 139 colon cancer patients with Dukes' B2 and C2 stage disease. Chemotherapy consisted of 400 mg/m(2) of 5-FU and 20 mg/m(2) of leucovorin injected daily for 5 days in every 4 weeks for a maximum of 12 cycles. The total dose of 5-FU administered per body surface area had a significant effect on the 5-year disease-free survival and 5-year overall survival in stage B2 and C2 colon cancer patients (P=0.0018, P=0.0011). Analysis with reference to the median DSDI demonstrated that there was a significant difference in 5-year survival in Dukes' C2 (P=0.0016), but survival was not affected by the dose intensity. Multivariate analysis demonstrated that only the total dose of 5-FU administered per surface area affected the 5-year disease-free survival and 5-year overall survival (P=0.0016, P=0.0007, respectively). It can be concluded that the total dose of 5-FU administered is important in planned dosage schedule of adjuvant chemotherapy in colon cancer.

Cancer Chemotherapy Update: Protracted Venous Infusion Fluorouracil for Advanced Colorectal Cancer

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column reviews various issues related to the preparation, dispensing, and administration of cancer chemotherapy, both commercially available and investigational.

High-Dose Fluorouracil and Leucovorin: Weekly Continuous Infusions for Metastatic Colorectal Cancer

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column reviews various issues related to the preparation, dispensing, and administration of cancer chemotherapy, both commercially available and investigational.

Racial differences in colorectal cancer mortality. The importance of stage and socioeconomic status

This investigation studies racial and socioeconomic differences in mortality from colorectal cancer, and how they vary by stage and age at diagnosis. Cox proportional hazards models were used to estimate the hazard ratio of dying from colorectal cancer, controlling for tumor characteristics and sociodemographic factors. Black adults had a greater risk of death from colorectal cancer, especially in early stages. The gender gap in mortality is wider among blacks than whites. Differences in tumor characteristics and socioeconomic factors each accounted for approximately one third of the excess risk of death among blacks. Effects of socioeconomic factors and race varied significantly by age. Higher stage-specific mortality rates and more advanced stage at diagnosis both contribute to the higher case-fatality rates from colorectal cancer among black adults, only some of which is due to socioeconomic differences. Socioeconomic and racial factors have their most significant effects in different age groups.

Weekly Fluorouracil and Leucovorin as Adjuvant Therapy for Early Stage Colon Cancer or Primary Therapy for Advanced Colorectal Cancer

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column reviews various issues related to the preparation, dispensing, and administration of cancer chemotherapy, both commercially available and investigational.

A Critical Appraisal of Treatment for T3N0 Colon Cancer

The purpose of this study was to evaluate the impact of adjuvant chemotherapy on survival after surgery for T3N0 colon cancer. All patients with node-negative (N0) colon cancer with tumor invasion beyond the muscularis propria (T3) treated with colectomy between 1982 and 1995 at a single institution were included. Patients were divided into two groups depending on postcolectomy treatment with or without adjuvant chemotherapy. Groups were evaluated to determine perioperative and pathologic variables that could potentially influence outcome and surveillance data to determine disease-free and overall survival. In 253 patients with T3N0 colon cancer 226 remained under observation and 27 were treated with adjuvant chemotherapy. The groups were similar ( P = not significant) when compared for tumor location, size, differentiation, number of nodes harvested, and transfusion requirements. Four of the 27 patients who received chemotherapy developed a recurrence (14.8%), whereas 22 of the 226 observation patients developed a recurrence (9.7%). Disease-free survival for the chemotherapy group at 5 years was 84 per cent and for the observation group 87 per cent. Statistical analysis (Mantel-Cox) showed no significant difference between the groups on the basis of survival ( P = 0.3743). We conclude that resection alone is a highly effective treatment for T3N0 colon cancer leaving limited opportunity for adjuvant chemotherapy to significantly impact survival. Adjuvant chemotherapy for T3N0 colon cancer patients should be limited to patients enrolled in clinical trials designed to identify subgroups of T3N0 colon cancer patients at a survival disadvantage or less toxic adjuvant chemotherapies.

Colorectal cancer staging and adjuvant chemotherapy

Colorectal cancer is a significant cause of morbidity and mortality in Western populations. The standard of care for staging patients with colorectal cancer to determine prognosis and identify patients who will receive adjuvant therapy continues to be histopathology of regional lymph nodes. However, the significant variability in survival within each staging category likely reflects the heterogeneity of detecting micrometastatic disease employing this technique. Novel molecular markers of micrometastases currently in development will permit more accurate staging of patients with colorectal cancer. These advances in staging will distinguish patients who will maximally benefit from adjuvant therapy from those who have an especially good prognosis in whom chemotherapy can be avoided. In addition, new adjuvant chemotherapeutic agents, novel combinations of those agents and creative dosing schedules currently being investigated will offer considerable advantages with respect to ease of administration, safety and tolerability, quality of life and efficacy. Ultimately, it is anticipated that advances in molecular diagnostics will define unique biochemical characteristics of patients' tumours, permitting individualization of chemotherapeutic regimens employing novel agents that specifically exploit those characteristics.

Investigation of the comparative toxicity of 5-FU bolus versus 5-FU continuous infusion circadian chemotherapy with concurrent radiation therapy in locally advanced rectal cancer

PURPOSE

To compare the relative toxicities of bolus versus infusional 5-FU chemotherapy administrated concurrently during external beam irradiation in patients with locally advanced rectal cancer following surgical extirpation.

METHODS

A total of 26 eligible patients were retrospectively identified as having been treated for rectal adenocarcinoma at the Stratton VAMC between 1989 and 1997. A comparative analysis of treatment dose intensities, treatment delays and toxicities in these patients was performed.

RESULTS

Significantly less WBC toxicity was observed in the patients receiving infusional 5-FU chemotherapy. The other toxicities, with the exception of skin toxicity, were generally less frequent in the 5-FU infusional group. When the toxicities were corrected for 5-FU dose intensity, to yield toxicity per mg of 5-FU, statistically significant differences were found for hematological toxicity (WBC and platelets), and for gastrointestinal toxicity (frequency and severity of diarrhea and weight loss). The majority of patients receiving infusional 5-FU therapy were treated using a circadian pattern of treatment peaking around the time of the radiation therapy. Patients receiving infusional 5-FU were able to tolerate over twice the dose intensity as those receiving bolus administration. Local recurrence rate in all patients was 3.8% comparing favorably to other reported studies. Distant recurrence frequency was also acceptable at 34.6% for the group.

CONCLUSION

Infusional 5-FU chemotherapy compared with bolus therapy during pelvic radiation minimizes toxicity to the patient while maximizing the dose of 5-FU that can be delivered. As infusional 5-FU therapy during radiation has previously been shown to increase disease free duration and survival, infusional 5-FU should be considered as an acceptable standard of care to prevent local recurrence of rectal adenocarcinoma following its resection. Shaping this infusional 5-FU chemotherapy within the day so that most of the daily dose is delivered around the time of the radiation therapy may further modify the toxic therapeutic ratio of combined modality therapy.