Breast Cancer Thirty Years Later: A Comparative Study between a 1983-1984 and a 2012-2013 Cohorts of Argentine Women

Background: In Argentina the breast cancer is the most common cancer among women with an incidence rate (ARS) of 71, 2 x 100,000. Changes in the patterns of behavior of women in the last 30 years with the adoption or increase of certain behaviors considered as risk factors for breast cancer may influence on the clinical, surgical, pathological and epidemiological patterns of presentation of the breast cancer. Purpose: A comparative study of the characteristics of the breast cancer in two cohorts of Argentinean females with a difference of 30 years at the time of diagnosis (1983-2013) was made to show differences, if any, between the profiles of presentation and diagnosis. Methods: Data available in both series were age at recruitment, menstrual history (menarche, menopause), exogenous hormone use and reproductive history. Medical data: breast self-examina- tion (knowledge and practice), personal breast pathology his- tory, personal and family history of breast cancer were available in both series. TNM clinical staging, histological diagnosis and diagnostic methodology data (self-breast examination, clinical examination and mammography) were also available. Variables evaluated in both studies were compared settling down the sta- tistical significance of the differences observed. Results: The first series (1983-1984) was constituted by 1658 cases and the second (2012-2013) by 1732 cases.Both series are mostly made up of menopausal women (73, 9% vs. 72, 3 %) with a same average age of 59 at the time of diagnosis. Similar menstrual history (menarche: 44, 0% vs. 38, 6%). Cultural behaviors show: increased use of oral contraceptives (13, 4% vs. 37, 2 %), same number ofnulliparous (23, 1% vs. 19, 9 %),primiparous over 30 years of age declined (21, 2% vs. 11,7%) and breastfeeding more practiced (66, 0% vs.95, 0%). In the family history of BC an increase (20, 9% vs. 27,9%) was observed. Staging of tumors showed similar “early stages ” (0-IIIa) (88, 6% vs. 87,9%)and histology more “in situ” forms (2,5% vs.12,0%) in the most recent series. The practice of mammography high in both series showed a significant increase (82, 4% vs.94, 1%) Conclusion: Taken together the two cohorts show an epide- miological and clinic profile of “western” populations with few differences in presentation's profile in 30 years. If one considers our population cultural and genetic background with a strong European component the expected change in the presentation's profile of the female breast cancer seems to need more than one generation to occur and to resemble that of the geographic re- gion in which we are located (South America) and the levels of “Less developed regions” and “Medium human development “we have achieve as a country.