Etoposide added to weekly leucovorin (LV)/5-fluorouracil (5-FU) in LV/5-FU pre-treated patients with advanced colorectal cancer.

Background: We evaluated the efficacy and safety of the weekly combination of etoposide, leucovorin (LV) and 5-fluorouracil (5-FU) when administered as second-line chemotherapy in patients with relapsed/refractory advanced colorectal cancer (ACC), previously treated with weekly LV + 5-FU.
Material/methods: Etoposide was administered at 3 different dose levels (DL), in 3 groups of patients (total=60): DL-I - etoposide 80 mg/m2, 45 min i.v. infusion, DL-II - etoposide 120 mg/m2, and DL-III - etoposide 180 mg/m2. In all three levels etoposide was followed by LV 100 mg/m2 i.v., 1-hour infusion, and 5-FU 500 mg/m2 i.v. bolus. Treatment was administered until disease progression or unacceptable toxicity.
Results: No patients responded at DL-I, while 2 patients at DL-II and 3 at DL-III had a partial response (PR) (P<0.1). Two patients had stable disease (SD) at DL-I, 8 at DL-II, and 9 at DL-III (P<0.01). More patients progressed at DL-I (n=19) compared to DL-II (n=10) and DL-III (n=8) (p<0.0007). The time to progression was 17, 15, and 14 weeks, respectively, for DL-I, -II, and -III (P=0.9). Median survival was 30, 30, and 32.5 weeks, respectively, for DL-I, -II, and -III (P= 0.27). Toxicity was mainly neutropenia, diarrhea and mucositis at all DLs, significantly more intense in DL-III. No difference was noticed in responses between DL-II and DL-III, but toxicity in DL-III was more severe.
Conclusions: The combination of etoposide with LV+5-FU has limited activity when administered after failure of weekly LV+5-FU in patients with ACC.