Clinicopathological features of gastric cancer cases and aberrantly expressed recoverin.

Abstract

Cancer-associated retinopathy (CAR) is an ocular manifestation of a paraneoplastic syndrome whereby immunological reactions toward recoverin, a retina-specific calcium binding protein, and other retinal antigens aberrantly expressed in tumor cells lead to the degeneration of retinal photoreceptor cells. Recently we reported that aberrant expression of recoverin was identified in more than 50% of tumor cells and their cell lines from several kinds of cancers, including gastric cancer, lung carcinoma, and other cancers. To elucidate the clinicopathological significance of aberrantly expressed recoverin in cancer cells, we performed immunocytochemical analysis using a monoclonal antibody against human recoverin. Within 18 patients with different clinical stages (I-IV) of gastric cancer, the aberrant expression of recoverin in tumor cells was recognized in 6 out of 18 patients (2 out of 2 stage IA, 1 out of 1 stage IB, 2 out of 3 stage II, 0 out of 7 stage IIIA, 0 out of 1 stage IIIB, and 1 out 4 stage IV). The present data are consistent in part with the previous observations that recoverin-expressing cancer cells induced tumor immunity and provide a favorable prognosis for primary cancer in CAR patients.