The combination of postoperative local therapy with radiation plus fluorouracil and systemic therapy with a fluorouracil-based regimen significantly and substantively improves the results of therapy for rectal carcinoma with a poor prognosis, as compared with postoperative radiation alone.
A protracted infusion of fluorouracil during pelvic irradiation improved the effect of combined-treatment postoperative adjuvant therapy in patients with high-risk rectal cancer. Semustine plus fluorouracil was not more effective than a higher dose of systemic fluorouracil given alone.
The purpose of this study was to evaluate the effectiveness of several new approaches designed to enhance the activity of fluorouracil (5-FU) in the management of advanced colorectal cancer. A total of 429 patients were randomized to one of the following regimens: single-agent 5-FU, given by standard 5-day, intensive-course intravenous bolus technique; 5-FU plus high-dose folinic acid (leucovorin) or 5-FU plus low-dose leucovorin; 5-FU plus high-dose methotrexate (MTX) with oral leucovorin rescue; 5-FU plus low-dose MTX; and 5-FU plus cisplatin (CDDP). The median survival for patients receiving 5-FU alone was 7.7 months. The high- and low-dose leucovorin plus 5-FU regimens had median survivals of 12.2 and 12.0 months, respectively, and offered a significant survival advantage over 5-FU alone with one-sided P values of .037 and .050, respectively (P = .051 for each treatment after correction for prognostic variables). The only other regimen possibly associated with improved survival was high-dose MTX plus 5-FU, with a median survival of 10.5 months (P = .21, P = .076 corrected). In addition, both high- and low-dose leucovorin plus 5-FU regimens were associated with significantly improved tumor response rates (P = .04 and .001) and significantly improved interval-to-tumor-progression rates (P = .015 and .007) when compared with 5-FU alone. Only the low-dose leucovorin plus 5-FU regimen was associated with significant (P less than .05) superiority in each of the following parameters of quality of life: performance status, weight gain, and symptomatic relief. The overall most therapeutically favorable regimen in this trial was 5-FU given with low-dose leucovorin; fortuitously, this regimen is associated with very low drug cost. Whereas this is the first study to demonstrate both improved palliation and survival for any regimen compared with 5-FU given by rapid intravenous (IV) injection for 5 consecutive days at a dose of 500 mg/m2/d in patients with advanced colorectal cancer, the magnitude of the gain is still relatively small. Our low-dose leucovorin plus 5-FU regimen is currently being studied in a national trial with the hope that this increased advanced disease activity may produce more substantive gains in the surgical adjuvant setting.
A total of 401 eligible patients with resected stages B and C colorectal carcinoma were randomly assigned to no-further therapy or to adjuvant treatment with either levamisole alone, 150 mg/d for 3 days every 2 weeks for 1 year, or levamisole plus fluorouracil (5-FU), 450 mg/m2/d intravenously (IV) for 5 days and beginning at 28 days, 450 mg/m2 weekly for 1 year. Levamisole plus 5-FU, and to a lesser extent levamisole alone, reduced cancer recurrence in comparison with no adjuvant therapy. These differences, after correction for imbalances in prognostic variables, were only suggestive for levamisole alone (P = .05) but quite significant for levamisole plus 5-FU (P = .003). Whereas both treatment regimens were associated with overall improvements in survival, these improvements reached borderline significance only for stage C patients treated with levamisole plus 5-FU (P = .03). Therapy was clinically tolerable with either regimen and severe toxicity was uncommon. These promising results have led to a large national intergroup confirmatory trial currently in progress.
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