The aim of our retrospective study was to analyze distribution of histological types, age of patients and hormonal dependency of breast cancer cases in the period 1980-2000 using computer database "Thanatos". This period was divided with regard to the war into a pre-war (1980-1990), war (1991-1995) and post-war period (1996-2000). We also paid attention to the Chernobyl accident (pre-Chernobyl from 1980-1986 and post-Chernobyl from 1987-2000). Special attention was focused on the period during the war mainly due to the fact that very little data exist in literature dealing with the war as a stress factor that may have induced and promoted carcinogenesis. During this twenty-one year period 2296 patients were diagnosed with breast cancer. In the female population of 2274, 2228 (98%) of these were ductal and only 46 (2%) were invasive lobular carcinomas. In all of the male cases (22) the cancer was pathohistologically verified as the invasive ductal type. The male:female ratio was 1:103. Comparing the pre-war and war periods we found a more than double increase in the male:female ratio (from 1:131 to 1:66). We observed similar results when we looked at the period after the Chernobyl incident where the ratio increased from 1:139 to 1:79. When we analyzed the distribution of histological types we found a significant increase in lobular carcinomas during the post-war period, from 1.1% to 5.5%; this increase was less significant for the post-Chernobyl period (1.0% to 3.3%). The average age of the patients with invasive ductal carcinomas increased from 56.7 yrs during the pre-war period to 59.7 yrs during the war and finally to 61.1 yrs during the post-war period. The average age of males with breast cancer decreased from 63.6 and 63.5 during the pre-war and war periods to 58.8 yrs during the post-war period. These results suggest that the war could have influenced the shift in the age of occurrence of breast cancer in both sexes appearing in younger males and in females in their postmenopausal period. The most commonly diagnosed stage of invasive ductal carcinoma during the war and post-war periods was T1N0MX, but in the controlled pre-war period the most frequently diagnosed stage was T2N1MX. With this we see that the increase in the age of the patient is not due to a more advanced pTNM stage which suggests that the increased age of our patients seeking medical help is not due to the incapacitating effects that the war may have on people needing medical attention. Our results showed that most of the patients were ER positive (72% throughout the twenty-one year period) and their average rate and number increase with the age of the patient. We found a significant drop in hormone dependent tumors in the period from 1991-95, which could mean that tumors in a war environment manifest a more aggressive phenotype. Our results show that the war within our region most likely had an effect on some clinical parameters involving breast cancer patients. Possible effects caused by "Chernobyl" could not be proved due to the overwhelming effect that war had upon the patients within this region.