[Biochemical modulation of 5-FU--effect of low dose CDDP]

A pilot study of continuous or intermittent low dose 5-FU and cisplatin chemotherapy (low-dose FP therapy) was conducted at the Department of Surgery of Sapporo Medical University School of Medicine (Group A) and Sapporo Tsukisamu Hospital, and at the Department of Internal Medicine of the Kochi Prefectural Center Hospital (Group B). The cases with esophageal cancer, stomach cancer, pancreatic cancer, hepatocellular carcinoma or colonic cancer co-existing with their inoperable lesion(s) were considered in this chemotherapy. The rates of complete and partial response and of side effects were studied. Also, the effects of low-dose FP on the prognosis of the patients with pancreatic or colonic cancers were investigated. The procedure consisted of continuous 5-FU 320 mg/m2 i.v. with daily CDDP 2.5 mg/m2 i.v. for five days/week rescue was performed for at least four weeks as a rule. The rates of complete response and partial response were 64% (Group A) and 56% (Group B) in esophageal cancer, 62% (Group A and B) in stomach cancer, 48% (Group A) and 57% (Group B) in colonic cancer, and 8% (Group A) and 21% (Group B). The overall response rate was 57.8%. The frequencies of severe side effect(s) (grades 3 and 4) were within three to eight percent, and no death from side effect(s) was experienced. The effects of low-dose FP therapy on the prognosis of stage IV colonic cancer and stage IV b pancreatic cancer were studied retrospectively. It is suggested that this chemotherapy might contribute to the survival of patients with these two cancers. Otherwise, the chemotherapy of intermittent administration (day by day) of 5-FU 750 mg/m2 i.v. and CDDP 2.5 mg/m2 i.v. was selected in order to decrease the rate of side effects and their severity. The pilot study encountered no severe side effects, no cases with grade 4 side effect were experienced but the remission rates were mostly similar to that of sequential low-dose FP therapy. However, the side effect of low grade ones as symptoms in gastrointestinal tract were observed in more patients. We concluded that sequential or intermittent 5-FU/CDDP therapy might be fairly effective, and since the adjuvant chemotherapy of choice for advanced or recurrent gastrointestinal cancer, their FP therapy might be one of the adjuvant treatments.