Neuroendocrine Carcinomas of the Colon and Rectum: Result of a 15-year Experience

Abstract

Purpose. The experience of the uncommon malignancy, neuroendocrine carcinomas of the colon and rectum with emphasis on the pathology and clinical characteristics at a single hospital was reviewed. Methods. Of more than 11,000 colon or rectal cancers removed from July 1992 to June 2007 at Chang Gung Medical Center in Taipei, 11 cases diagnosed as colon or rectal neuroendocrine carcinoma were evaluated. Pathology was reviewed by a single pathologist. Medical records were retrospectively reviewed and patients were analyzed in terms of clinicopathologic and demographic characteristics including neuroendocrine type, tumor location, tumor stage, responses to treatment (operative procedure, chemotherapy or radiotherapy), metastases, and survival. Results. Five patients had distant metastasis at the time of diagnosis. Palliative chemotherapy or radiotherapy did not seem to offer a modest improvement in survival for these patients, with an overall survival of less than 11 months after diagnosis. Lymph node metastasis was found in 75%, and the distant metastasis in 45% of the 11 patients at the time of diagnosis. Overall survival rates for six-month, one-year, and three-year survival were 73 percent, 45 percent, 20 percent, respectively. These findings are in accordance with other publications, which demonstrate that the neuroendocrine carcinomas behave aggressively and are associated with worse prognosis than that of conventional adenocarcinomas of the same stage. Unexpectedly, improved results were found for two stage IIA and IIIB rectal small cell neuroendocrine carcinoma patients administered with adjuvant chemotherapy treatment with cisplatin and etoposide at our hospital. They were alive without evidence of disease at more than 10 years after treatment. Conclusions. Neuroendocrine malignancies are rare but behave aggressively in the colon or rectum, accounting for less than 0.1 percent of all colorectal cancers at our institution. Aggressive adjuvant chemotherapy with cisplatin and etoposide might offer a better chance of long-term survival for patients with stage Ⅱ and Ⅲ neuroendocrine carcinomas in the colon and rectum, which deserves further investigation.