Comparison of clinical characteristics between occult and non-occult breast cancer.

PURPOSE To compare the clinicopathological characteristics of patients with occult (OBC) and non-occult breast cancer (non OBC). METHODS A total of 93 female patients with OBC registered at the First and Second Affiliated Hospitals of Zhejiang Chinese Medical University from January 1980 to December 2005 were included in this retrospective study. Their clinicopathological data were analyzed and compared with those from 1,576 female patients with non OBC, registered during the same time period. RESULTS The rates of estrogen receptors (ER) and progesterone receptors (PR) in OBC cases were 46.2 and 56.6%, respectively, and 44.1 and 55.6%, respectively (p<0.05). The overall 5- and 10 horbar;year overall survival rates for OBC were 51 and 43%, respectively; the overall 5 horbar;year survival rates for stage 0 horbar;I, stage II and stage III OBC patients were 90, 83 and 52%, respectively, while the overall 10 horbar; year survival rates of the three stage groups were 83, 76 and 42%, respectively. CONCLUSIONS Compared to non OBC, the ER positive rate of OBC was lower. Furthermore, no significant difference was noticed in 5 horbar; and 10 horbar;year survival rate between OBC and stage III non OBC patients.