A considerable number of metastatic colorectal cancer (mCRC) patients who progress on standard treatment with 5-fluorouracil (5FU), oxaliplatin, irinotecan and monoclonal antibodies, still have adequate performance status and desire further treatment. Mitomycin C (MMC) has been widely used in this context, and despite good tolerability, there are doubts regarding its true benefit.

In order to assess the activity of MMC in the refractory mCRC setting, we retrospectively evaluated 109 heavily pre-treated patients who received MMC as single agent or in combination for mCRC at three different institutions in two countries.

Median patient's age was 54years old, 57% were male and 94% had performance status ECOG 0 or 1. MMC was used in second line in 11%, third line in 38% and fourth line or beyond in 51% of patients. 58% received MMC combinations, mainly with capecitabine. Grade 3 or 4 toxicity was observed in 5% of patients and 6% required dose reductions. Median time to treatment failure (TTF) was 1.7months with MMC and 3.6months on the regimen prior to MMC, with a ratio between these TTF below 1 in 82% of patients. Median survival was only 4.5months (95% confidence interval (CI) of 3.48-5.56).

This retrospective data represent the largest reported series of unselected refractory mCRC patients treated with MMC. The median survival of 4.5months is similar to the survival expected for best supportive care. This lack of activity strongly suggests that MMC should not be routinely used in refractory mCRC.

Copyright © 2012 Elsevier Ltd. All rights reserved.

PMID: 22330318 [PubMed - as supplied by publisher] Source: National Library of Medicine.