BACKGROUND/
AIMS: Colorectal
neuroendocrine carcinoma is a rare
neoplasm exhibiting fulminant progression and having poor
prognosis . The purpose of this study is to verify the clinicopathologic characteristics of colorectal
neuroendocrine carcinoma .
METHODS: From June 1997 to December 2004 at Asan Medical Center, ten
patients were originally identified as colorectal
neuroendocrine carcinoma on the basis of H&E and immunohistochemical
staining (IHC).
Carcinoid tumors were excluded in this study.
Medical records of thirteen
patients were reviewed retrospectively.
RESULTS: Ten
patients (0.2%) with colorectal
neuroendocrine tumors were identified from 4,512
patients with
colorectal cancer ; ten
neuroendocrine carcinomas and three
adenocarcinomas with neuroendocrine differentiation. Their median age was 60 (41-83) years. The subjects consisted of six
males and seven
females . Nine
tumors were located in the
rectum , two in the
sigmoid , and each one in the
transverse colon and
cecum , respectively. Nine of ten
neuroendocrine carcinomas expressed
synaptophysin , but
chromogranin A were expressed in four. All
patients were advanced at the
time of
diagnosis , with AJCC
TNM staging stage IIIB (n=2), stage IIIC (n=3), and stage IV (n=8). The median
survival for ten
neuroendocrine carcinomas and three
adenocarcinomas with neuroendocrine differentiation were 16.4 months and 30 months, respectively. Five
patients who received
chemotherapy showed median
survival of 32 months (stage III) and 17.5 months (stage IV), whereas other five
patients without
chemotherapy died with a median
survival of 6.2 months.
CONCLUSIONS: Colorectal
neuroendocrine tumors are extremely rare showing aggressive
behavior biologically, i.e fulminant early distant
metastasis . Nevertheless, improved
survival may be achieved by aggressive multimodality
therapy .