O. Yazici

273PTHE ONLY PROGESTERONE RECEPTOR POSITIVE BREAST CANCER PATIENTS HAVE TOTALLY DIFFERENT CLINICAL FEATURES COMPARED TO TRIPLE NEGATIVE COUNTERPARTS: IS IT TRUE?

ABSTRACT Aim: In literature many trials reported that estrogen receptor (ER)-negative; progesterone receptor (PR)-positive breast carcinomas are biologically different from ER + PR+ tumors and have a poor clinical outcome. However, biological significance of only PR positive tumors is unclear. Although the only PR positive breast cancer patients treated as hormone receptor positive patients, clinically they behave more aggressive than hormone receptor positive tumors. Therefore, we aimed to retrospectively compare the clinical parameters and survival rates of the only PR positive breast cancer patients with triple negative patients. Methods: We retrospectively evaluated the data of triple negative and the only PR positive breast cancer patients who admitted to department of medical oncology in Hacettepe University and Ankara Numune Education and Research Hospital between years 2002 and 2013. We exclude the data of ER and/or HER-2 receptor positive breast cancer patients. The clinical characteristics and survival ratios of the only PR positive patients compared with triple negative patients. Results: The total 449 patients were included in study [Triple negative n = 349, the only PR positive n = 100]. The median follow up time was 46 (min:3- max:312) months. The mean age at diagnosis in triple negative and PR positive group was 48.1 ± 12 and 47.6 ± 10, respectively, difference was not significant. Menopausal status, histological subtypes, lymphovascular and perineural invasion rates, histological grade, comorbid diseases, were similar between two groups (p > 0.05). At the time of diagnosis the rate of metastatic disease in triple negative and PR positive group were 6.6% and 4%, respectively (p = 0.59). The 90% of PR positive group had hormonal therapy. In PR positive and triple negative groups the rates of patients who had radiotherapy and chemotherapy as follows; 74% and 71%, 87 and 84%, respectively (p > 0,05). The estimated disease free survival time for PR positive and triple negative group was, 157 (95% CI, 92-221) months and 166 (95% CI, 144-187) months (p = 0.75). In triple negative and PR positive group the 5 th year overall survival rates were similar (82% versus 83%, p = 0.92). Conclusions: In this study we showed that the only PR positivite breast cancer patients had similar clinical features and survival rates with triple negative counterparts. Disclosure: All authors have declared no conflicts of interest.