%0 Journal Article %T Micropapillary Pattern at the Invasive Front and Its Association with Unresectable Colorectal Carcinomas %A Naohiko Akimoto %A Takahiro Fujimori %A Hiroyuki Mitomi %A Kazuhito Ichikawa %A Shigeki Tomita %A Atsushi Tatsuguchi %A Shunji Fujimori %A Zenya Naito %A Choitsu Sakamoto %J Disease Markers %D 2013 %R 10.1155/2013/851623 %X Unresectable colorectal carcinomas (CRCs) as considered incurable even if the primary tumors and the metastatic ones can undergo resection are correlated with poor prognosis. We evaluated the association between micropapillary pattern at the invasive front and unresectable CRCs. Thirty-four out of 264 (12.9%) CRC patients with stages III and IV were unresectable cases. The patients with unresectable CRCs had significantly worse survival than those with resectable CRCs ( ). Micropapillary pattern was evident in 12 (4.5%) out of 264 cases. This pattern was observed in 6 of 34 (17.6%) unresectable CRCs and in 6 of 230 (2.6%) resectable cases ( ). Unresectable CRCs revealed more frequently deeper invasion (odds ratio (OR), 1.175; 95% confidence interval (CI), 1.113¨C1.241), lymph node metastasis (OR, 2.356; 95% CI, 1.132¨C4.905), and presence of micropapillary pattern at the invasive front (OR, 8.000; 95% CI, 2.415¨C26.504) as compared to resectable cases. By multivariable logistic regression analysis, only micropapillary pattern was shown to be an independent predictor of unresectable CRCs (OR, 9.451; 95% CI, 2.468¨C36.196; ). In conclusion, micropapillary pattern at the invasive front is associated with unresectable CRCs, and detection of it could help identify unresectable CRC cases. 1. Introduction Colorectal cancer (CRC) is a major cause of death in Japan, where it accounts for the largest number of deaths from malignant neoplasms in women and the third largest number in men [1]. The cumulative 5-year survival rates of Japanese CRC are 90.6% at stage I, 81.2% at stage II, 63.7% at stage III, and 13.2% at stage IV [1]. Unresectable CRCs are considered incurable even if the primary tumors as well as the metastatic ones are able to undergo resection, has been correlated with poor prognosis [2]. We previously reported that the preferential site and age of unresectable CRCs were not different from resectable CRCs, but K-ras mutations were more frequent in the latter [3]. The survival of unresectable CRC patients has dramatically improved with the progress in chemotherapeutic regimens such as new routes of administration and introduction of more potent cytotoxic agents. Biologic therapy in combination with chemotherapy leads to improved progression-free survival and overall survival in some cases such as the addition of cetuximab to cases with wild-type K-ras tumors [4]. For patients with an asymptomatic intact primary tumor, the initial prediction of metastatic potential is important for early intervention before disease progression to unresectable CRC. %U http://www.hindawi.com/journals/dm/2013/851623/