Study With Mitomycin c/5-FU/FA in Pretreated Gastrointestinal Cancer Patients With Metastases (>= Second-line Treatment)

Inclusion Criteria: Phase 1 (dose escalation) * patients with histological proven gastrointestinal neoplasms, without standard therapy option * measurable or evaluable disease * \>= second-line therapy (metastasized stage) Phase 2 (efficacy) * patients with proven colorectal neoplasms * measurable disease, metastasized * previous chemotherapy with 5-FU/FA ("AIO-regimen") * age between 18 and 75 years, both male and female * life expectancy \> 3 months * WHO-performance status \<= 2 * adequate bone marrow function: hemoglobin \>= 10 mg/dl, neutrophils \>= 2.0 \* 1000000000/l, thrombocytes \>= 150 \* 1000000000/l * adequate renal and liver function: bilirubin \<= 1.25 \* ULN(\<= 1.5 ULN \* by liver metastases), creatinine \<= 1.25 \* ULN, ASAT and ALAT \<= 3 \* ULN (\<= 5\* ULN by liver metastases; AP \<= 3\* ULN * written informed consent prior to inclusion into the study Exclusion Criteria: * pretreated with mitomycin c * contraindication concerning 5-FU (e.g. anxiety, myocardial infarction within last 6 months, significant toxicities during previous therapy with 5-FU * florid infections * ileus or subileus, morbus crohn or colitis, ulcerative * actual chronic diarrhea * other uncontrolled severe concurrent disease excluding cytotoxic intervention * second malignancy except basal cell carcinoma or cervical carcinoma in situ * known cns metastases or carcinomatous leptomeningitis * pregnancy or lactation period * no effective contraception * concomitant treatment with another antineoplastic agents * participation in another clinical trial within the last 4 weeks * patients being unwilling or unable to undergo trial specific procedures