Epidemiology of invasive breast cancer according to histopathologic and immunohistochemistry prognostic factors

The aim of this study was to analyze the TNM classification factors of invasive breast cancer that can be affected by the national program for early detection of breast cancer in the Republic of Croatia. The other analyzed factors related to histology and immunohistochemistry have no such impact as they are related to biological behavior and aggressiveness of malignant breast tumors, thus providing useful predictive and prognostic information. The study was performed at Department of Oncologic Surgery, Sestre milosrdnice University Hospital Center, and included 75 patients surgically treated for invasive breast cancer during the period of one month in 2011, mean age 64 +/- 11.36 (range 36-86) years. Most of the patients (68%) with malignant breast disease were diagnosed in a localized stage, which is consistent with the reports from developed European countries. The size of the newly discovered tumors showed continuation of a trend of detecting tumors of ever less size and a lower percentage of pT3 pT4 tumors. This result proved superior to those reported from many European countries. The results of correlation analysis, tumor size, estrogen and progesterone receptor, HER-2 protein, Ki-67, and histologic tumor grade, tumor size did not show significant correlation with any of these parameters. Concordant expression of phenotype (ER+, PR+) receptor pairs and negative HER-2 was recorded in most study patients. The second most frequent group had tumors with so-called 'triple-negative' immunohistochemistry negative phenotype (ER-, PR-, HER-2). In conclusion, the program of early detection of breast cancer in the Republic of Croatia and at the University Hospital for Tumors justifies its existence for revealing malignant breast tumors at an earlier stage of the disease considering the size local stage of newly diagnosed tumors.