Primary adenocarcinoma of the anus: a 22-year SEER population database analysis

e15072

Background: Most anal canal cancers consist of squamous cell carcinoma (SCCA). Adenocarcinoma (AdenoCa) is rare and accounts for approximately 10% of anal cancers. A search of the SEER database (1973 to 2005) was carried out to evaluate the pattern of radiation (RT) and surgical treatment. Impact of the treatment on overall survival (OS) was evaluated. Methods: The search of the SEER database revealed 1,008 pts who had pathologically confirmed anal cancers with either SCCA or AdenoCa. All pts had single diagnosis of anal cancer with localized disease without nodal involvement. Excluded were pts with unknown use of surgery or radiation. Kaplan-Meier estimates and Cox-Mantel model were used to calculate and compare survival rates. Results: Median age of all pts was 57 years (range 29 to 99). For the SCCA group, median age was 57 years (range 29 to 99), which was younger than the AdenoCa group with median age of 74 years (range 37 to 92). Among the 1,008 pts, 954 had SCCA (94.6%), and 54 had AdenoCa (5.4%). Within the SCCA group, 14 (1.5%) had abdominoperineal resection (APR) in combination with external beam RT, and 795 (83.3%) had RT only with non-APR local surgical treatment inclusive of excision. Remaining 145 SCCA pts (15.2%) had non-APR local surgical treatment only without RT or had no treatment. Within the AdenoCa group, 10 (18.5%) had APR in combination with external beam RT, and 21 (38.9%) had RT only with non-APR local surgical treatment inclusive of excision. Remaining 23 AdenoCa pts (42.6%) had non-APR local surgical treatment only without RT. None of the adenoCa pt had no treatment. OS at 10 years was superior for pts with SCCA vs. AdenoCa (64.9% vs. 25.8%, p<0.05). Among the SCCA subset, there was no signficant difference in the 10-yr OS between the APR versus the RT pts (71% vs. 65%, p=0.78). On the other hand, among the AdenoCa subset, pts who had APR had better 10-yr OS than RT pts (53.8% vs. 0%, p=0.03) Conclusions: For localized anal SCCA, RT yielded equivalent overall survival as compared to APR. On the other hand, pts with localized anal adenoCa appeared to do worse when APR was omitted. RT only without APR might not be sufficient treatment in these patients. This database lacks information on use of chemotherapy and local disease control. Omission of APR in pts with anal canal adenoCa should be cautiously weighed.

No significant financial relationships to disclose.

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

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.