CHROMOSOMAL ALTERATIONS IN PATIENTS WITH BREAST CANCER

Today, breast cancer (BC) is the most commonly occurring cancer among women. Several studies have suggested that the proportion of BC can be attributed to a genetic factor that may be as high as 30%. The aim of the present study was to describe the types and frequencies of chromosomal abnormalities (CAs) in BC patients. Fifty-one patients were analysed as part of an ongoing study of the cytogenetics of BC. Cytogenetic analysis of blood samples was conducted by Giemsa‑banding in patients with BC. The karyotype results were normal in 68.6% of 51 patients; however, CAs were detected in 31.4% of the patients. The 27.5% and 3.9% of the patients exhibited structural aberrations (transloca­tions, deletions, inversions, duplications and fragilities) and numerical aberrations, respectively. Specifically, the deletions and fragilities among structural aberrations were the most common karyotypes (9.8% and 7.8%, respectively) among the patients. Deletions included del(7p11), del(7q32), del(9p32), del(11q23) and del(11q15). Inversions were present in 3.9% of all patients, and included inv(21)(q11;q21) and inv(11)(p15;q12). Translocations were detected in one patient (2%) and the frequency of other CAs, different to those types already mentioned, was 5.9%. Regarding numerical CAs, two patients (3.9%) had aneuploidies. This study demonstrated that genetic instability existed in 31.4% of BC patients, and emphasizes the importance of combined cytogenetic analysis for the diagnosis of BC. The 7p11, 7q32, 9p32, 11p15, 11q12, 11q23, 21q11, 21q21, 15p11 and 17q23 regions are becoming a model for understanding chromo­somal regions in BC. It seems that the presence of 11q and 7q deletions may play an important role in the development of BC. If so, different chromosome anomalies might have different pathogenetic and/or prognostic significance.