Our purpose was to evaluate the safety and therapeutic activity of continuously infused mitomycin C in patients with recurring or progressive metastatic gastric cancer following first-line chemotherapy. Patients were treated with mitomycin C 20 mg/m2 i.v. over a time period of 120 h followed by a 3-week rest period. All patients received prednisone 50 mg p.o. prophylactically for 5 days to prevent hemolytic uremic syndrome and pulmonary side effects. Twenty-two consecutively enrolled patients were assessable for toxicity and 20 for response evaluation completing at least one full course of chemotherapy (two patients evaluable but not measurable).
Patient characteristics: median age: 63 years (39-76); Sex (M/ F): 13/9; median Karnofsky status: 70% (50-100%); resection of primary tumor n = 12 (55%); sites of metastases: liver n = 17 (77%), locally advanced n = 10 (45%), peritoneum n = 13 (59%), lungs n=5 (23%), bone n=3 (14%) and lymph nodes n=14 (64%). Previous chemotherapy regimens: bolus 5-FU/folinic acid n=6 (27%), ELF n=4 (18%), EAP n=3 (14%) and continuous 5-FU/folinic acid/cisplatin/paclitaxel n=9 (41%). In 20 evaluable patients one complete and five partial remissions were observed; overall response rate 30.0% [95% confidence interval (CI): 9.1-50.9%] with a median response duration of 2.1 months (range: 2-6). The median survival was 3.6 months (95% CI: 2.1-6.0) resulting in a 6-month survival rate of 30% since start of mitomycin C. WHO grade III/IV mucositis, diarrhea and fever/infection occurred in 9% of patients each. Cumulative thrombo- and leukocytopenia (WHO grade II/IV) were observed in four and two patients, respectively. Treatment had to be stopped early in two patients. No severe renal dysfunction, pulmonary toxicity or evidence of hemolytic uremic syndrome was observed. Fatigue during the 120 h infusion of mitomycin C was common (11 of 22 patients). We conclude that continuous infusion of mitomycin C is feasible on an outpatient basis, revealing an acceptable toxicity. Mitomycin C demonstrates single-agent activity in pretreated gastric cancer, but has only limited efficacy following cisplatin/paclitaxel-based first-line chemotherapy.