Gemcitabine (gem) as salvage therapy in metastatic colorectal adenocarcinoma (mCRC).

Abstract

e14135 Background: When unresectable mCRC becomes refractory to standard therapies, physicians will at times resort to non-standard palliative therapies such as gem plus a fluoropyrimidine. The activity of gem in this setting, however, has not been well established. The limited data available are largely from abstracts that were not followed up by manuscripts, and are thus of limited utlility. Methods: After obtaining an IRB waiver of authorization we searched our institutional database to retrospectively identify all mCRC patients at MSKCC who received gem in combination with either capecitabine or intravenous 5FU after progression on all standard therapies from 1/1999 through the present. We reviewed the patients' (pts) medical records including pathology reports, progress notes, imaging studies and radiology reports to assess for suggestion of partial response (PR), stable disease (SD) and progression (POD) on gem-based chemotherapy. In all cases in which tumors were felt to have been stable or responding, actual CT scans were reviewed and formal response criteria (RECIST 1.1) were applied. Results: A total of 98 patients (pts) were identified. Two patients were determined to be uninterpretable due to inadequate scanning to permit assessment, and so were removed from the analysis. A total of 96 pts (42 females and 54 males) were evaluated. The median age was 62 (range 25-80). All pts had progressed by report on all standard therapies. No PRs were seen on gem-based therapy (0/96, 0%). A total of 9 pts (9%) experienced SD for ≥ 4 months. Overall, 82% of pts had overt tumor progression at the time of first on-treatment scan. Interestingly, one additional pt (not included in this analysis) with metastatic goblet cell carcinoid/adenocarcinoma of the appendix was found to have an unconfirmed PR. Conclusions: In this retrospective analysis, the antitumor activity of gem in combination with capecitabine or intravenous 5FU in chemotherapy-refractory mCRC was extremely limited. Our findings are consistent with the non-endorsement of gem-based chemotherapy in NCCN colorectal guidelines.