Breast cancer pathology patterns in Armenia.

e12586 Background: Breast cancer (BC) is the most common malignancy among the women in Armenia (AM). Currently there is a knowledge gap regarding the morphology distribution of the BC in AM. Methods: The data on patients with BC diagnosed in 2015-2016 in the pathology lab “Davidyants Labs” in AM were retrospectively reviewed. Pts with Her2+ results by IHC were excluded from the study, due to unavailability to perform FISH or CISH analyses. Overall 361 pathology reports were evaluated. Results: The median age was 54 years; range [19-82]. Histopathological subtypes were defined for 305 pts, from which lobular carcinoma 57.4% of cases (175/305), ductal carcinoma 26.9% (82/305), mucinous carcinoma 2.6% (8/305), mixed type carcinoma (lobular and ductal) 2.6% (8/305), DCIS 2% (n = 6/305), non specified carcinoma 2% (6/305), medullary carcinoma 1% (n = 3/305) and others 5.6% (17/305). Within the cohort 8.5% (23/270) were grade 1, 65.9% grade 2 (178/270); 25.6% grade 3 (n = 69/270). Vascular or lymphatic invasion was present in 59.5% (50/84) and 64.7% (55/85), respectively. Staging distribution, based on pT pN data for 92 pts who went to primary surgery, was: 0 stage 7.6% (7/92), I stage 22.8% (21/92), II stage 41.3% (38/92), III stage 28.3% (26/92). Staging distribution based on ypT ypN data for 27 pts who went to surgery after neoadjuvant chemo was 0 stage 25.9% (7/27), I stage 18.5% (5/27), II stage 29.6% (8/27), III stage 25.9% (7/27). ER and PR were defined for 244 patients. ER positive 89.8% (219/244) of cases, PR pos. 73% (178/244), ER/PR pos. 72.5% (177/244) cases. Her receptor was defined for 237 patients. Her3+ 16.9% (40/237); Her2+ 12.7% (30/237); Her1+ 38% (90/237); Her0 32.5% (n = 77/237). We could not evaluate Her2+ status by FISH or CISH, so these results were excluded from the analysis. Ki67 was low (≤20) in 42.1% (101/240) of cases and high ( > 20) in 57.9% (139/240). Within the group Luminal A type was 41.4% (84/203); Luminal B 32.5% (66/203); Her positive 19.7% (40/203) and triple negative 6.4% (13/203). p53 and perineural invasion (Pn) was present in 32% (16/50) and 52% (26/50), respectively. Tumor leukocyte infiltration was determined for 16 patients. Leukocyte infiltration was positive in 43.7% (7/16) cases, negative in 25% (4/16) cases, minimal in 31.3% cases (5/16). Conclusions: BC in Armenian women presents with different epidemiological characteristics in comparison with other ethnicities. Lobular type BC is the most frequent type among Armenian women, however, differential diagnosis between lobular/ductal carcinomas was done without IHC (E-Cadherin), which rises the need for further studies on that regard.