Complications and effectiveness of combination chemotherapy in metastatic colorectal cancer (MCRC) with unresected primary (UP)

Abstract

14537 Background: The outcome of patients (pts) with MCRC and unresected primary (UP) has not been studied systematically in the modern era of targeted and combination chemotherapy. We conducted a single institute retrospective study to determine the rate and nature of complications in this population. Methods: MCRC-UP pts treated at Roswell Park Cancer Institute between 2002 and 2006 were identified. Demographic, toxicity, efficacy, and palliative intervention data were collected. Primary tumor related complications including obstructive symptoms, bleeding, perforation, and fistulas were assessed. Results: 24 pts with colonic UP were identified. 14/24 were treated with bevacizumab-based chemotherapy (11 FOLFOX, 3 capecitabine), 7/24 with FOLFOX, 2 with capecitabine, and 1 with FOLFIRI. No perforations, hemorrhagic events, or arterial events were noted. None of the 24 pts required palliative surgical intervention secondary to the UP. Only 2 pts developed obstructive symptoms and 1 pt developed an entero-cutaneous fistula; all 3 events were attributed to peritoneal carcinomatosis. 10 pts with rectal UP were identified. 1 pt received upfront chemoradiation followed by 5-FU/bevacizumab. 9/10 pts were treated with upfront systemic chemotherapy (6 bevacizumab-based [5 FOLFOX, 1 capecitabine], 3 FOLFOX). Of these 9 pts, 4 required subsequent palliative radiation therapy for obstructive symptoms (3 pts) or pain (1pt) while 5 continue on systemic chemotherapy (median 1st line chemotherapy duration > 7 months). No perforations, bleeding requiring transfusion, or arterial events were noted among the rectal cancer population. 1 pt required a diverting colostomy for obstruction despite palliative CRT. Median time to progression on first line chemotherapy was 7.4 months for colon cancer and 8 months for rectal cancer. The median overall survival was 13.6 months for colon cancer and has not been reached for rectal cancer (exceeded 13 months). Conclusion: Treatment of MCRC with UP is feasible and is rarely associated with complications related to the primary tumor. Rectal cancer with UP can be managed with upfront chemotherapy. Subsequent palliative RT is needed in about 50% of these pts. No significant financial relationships to disclose.