Association of a characteristic membrane pattern of annexin A2 with high invasiveness and nodal status in colon adenocarcinoma.

The identification of tumor cells in lymph nodes is essential for the correct classification of patients with colorectal cancer who may benefit from adjuvant treatments. Proper classification of tumor stage becomes entangled by variables such as an insufficient number of lymph nodes examined, which can result in erroneous or missed diagnosis. The determination of pathologic factors in the primary tumor associated with positive lymph nodes is an area of research that has attempted to provide variables to solve this problem. In the present study, we observed that the localization of annexin A2 (AnxA2) in a cell membrane is the characteristic that distinguishes tumor cells with high invasiveness. Localization of AnxA2 expression was also studied in tissue specimens from 58 patients with invasive colorectal carcinoma (T3-T4), who had undergone colectomy with radical lymph node dissection. Interestingly, the membrane pattern observed in tumor cell lines was also identified in patient's tissue samples and allowed us to distinguish among different cell populations with the tumor. Univariate analysis showed that tumor deposits in pericolic fat, extramural vascular invasion, and amount of cells with AnxA2 membrane pattern in the tumor invasive edge had a significant influence on lymph node metastasis. On the contrary, multivariate analysis revealed that the number of cells with AnxA2 membrane pattern (P < 0.05) and tumor deposits (P < 0.05) was significantly associated with lymph node metastasis. Furthermore, AnxA2 cellular localization was observed in cell clusters that define tumor budding, and a significant association between both variables was detected.