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Chemotherapy for metastatic colorectal cancer: Why not take a break when it works?

3641 Background: Once objective tumor response (OR) or stable disease (SD) has been achieved in patients (Pts) undergoing palliative chemotherapy (CT) for metastatic colorectal cancer (MCRC), we propose a break, allowing the Pts a CT -free period with visit at 6 weeks then a CT every 3 months; in case of PD, CT is given.


PATIENTS AND METHODS
This retrospective series included a random selection of our Pts with MCRC who had had at least 1 break in their CT.


RESULTS
62 Pts, age 60.9 +/- 10.8 yrs, received palliative CT for MCRC and had had at least 1 break in their CT. A break was defined as a period when CT could have been but was not given. Periods of palliative care and interruptions due to side effects were not considered breaks. The 1st break took place in a 1st-line (n=61) or 2-line (n=1) protocol in patients who had OR (n=41) or SD (n=20) after a median 4.5 mo (no difference between OR and SD). Median duration of these 1st break was 6 mo. Kaplan-Meier plots showed that 52.5 +/- 6.4%, 30.7 +/- 6% and 20.5 +/- 5.2% of the Pts were still CT -free at 6, 9, and 12 mo. The CT -free period was longer after OR (median > 6 mo) than after SD (4 mo) (p<0.02). After their first break, 57 Pts received a 2nd CT, 35 with the same CT (10 OR, all after initial OR, 14 SD and 8 PD) and 22 with another CT. After this 2nd cycle, 40 Pts took another break (median 5 mo) and 29.5 +/- 7.4% remained CT -free at 6 mo, 13 % at 1 yr. A 3rd cycle was delivered for 32 Pts (median 3 mo) and 13 of them then had another break (median 4 mo); 9 resumed CT (6 mo) and 5 had another break (4 mo). Globally, Pts had CT for a median 8.5 mo (range 3-30) and was CT -free for a median 11 mo (1-75). Median time without CT was 1.3 times median time with CT. On October 10, 2003, 29 Pts had died, 4 were receiving best supportive cares, 14 were CT -free, and 15 were receiving CT. The 1-, 2- and 3-yr survival rates were 95.2 +/- 2.7%, 70.8 +/- 6.5%, and 48 +/- 8% (11 exposed patients).


CONCLUSIONS
From this retrospective analysis, we conclude that 1) responders can take a break in CT for MCRC, and 2) breaks can be repeated, 3) without compromising survival. The impact of this approach on quality-of-life, healthcare expenditures, and even overall survival is certainly worth evaluation in a large-scale prospective study. No significant financial relationships to disclose.