[Provision for adverse effect of S-1 containing chemotherapy in patients with advanced digestive cancer--combination with superfine dispersed lentinan].

OBJECTIVE

Recently, in drug therapy for patients with advanced digestive cancer, S-1 (tegafur x gimeracil x oteracil potassium) alone or S-1 combined with other chemotherapeutic agents (S-1+alpha) is prescribed. However, many patients are often forced to give up long-term S-1 treatment owing to high incidence rates of adverse effects. The purpose of this study was to evaluate the efficacy of superfine dispersed lentinan (SDL) for the suppression of adverse effects of S-1 or S-1+alpha.

METHODS

The subjects were 72 patients who had unresectable or recurrent advanced digestive cancer. The subject group consisted of 45 men and 27 women, with a median age of 64 (31-85) years; 29 gastric, 25 colorectal, 10 pancreatic and 8 other digestive cancer patients. Thirty -one patients were administered S-1 alone and 41 patients were administered S-1+alpha. SDL (15mg of lentinan/bag/day) was orally administered to all patients for 12 weeks. Adverse events and overall survival time were evaluated according to the CTCAE ver 3.0 and the Kaplan-Meier method, respectively.

RESULTS

Seventy-two patients were enrolled in this study. Adverse events which had an undeniable causal relationship to SDL were observed in 2 patients (2.7 %, constipation [Grade 2] and nausea [Grade 1]) out of 72 patients; all of the events were not severe and disappeared when the SDL administration was discontinued. Adverse events associated with S-1 or S-1+ alpha were observed in 9 patients (12.5% ) (11 events) out of 72 patients. Grade 3 adverse events were observed in 3 patients (4.2% ) (leukopenia, 2; thrombocytopenia, 1). Incidence rates of both hematological and nonhematological adverse events were very low. In no gastrointestinal toxicity associated with S-1 or S-1+alpha was observed, which was estimated to be an effect of SDL combination. Mean survival times in gastric cancer and colorectal cancer patients were 9. 5 months (95%confidential interval [CI], 7.0-22.4 months) and 18.4 months (95% CI, 13.2 -28.5 months), respectively.

CONCLUSIONS

From the results of the present study, SDL is considered completely free of anything harmful to advanced digestive cancer patients and is effective for the suppression of adverse effects of S-1 or S-1+alpha therapy. It is suggested that SDL can prolong the administration period of S-1 and, as a result, contribute to prolongation of survival in patients with advanced digestive cancer.