Background: Breast cancer is the most common cancer in Lebanese women. Lebanon has no national cancer registry and the American University of Beirut Medical Center (AUBMC) is one of the largest hospitals in Lebanon and has a fully operational cancer registry. Earlier studies showed that it sees about one third of all cancer cases in Lebanon.

Methods: All female breast cancer patients recorded at AUBMC between 1983 and 2000 were evaluated. We used the sex-specific age distribution of 1995 Lebanese Population and Housing Survey to estimate the age-specific incidence of breast cancer in Lebanon. The results were calculated as number and proportion of cases, 10-year age-specific incidence rates, crude rates and age standardized rates (ASR) per 100,000 population. The ASR per 100,000 population was estimated by the direct method with the use of the World Standard Population.

Results: Between 1983 and 2000, there were a total of 16421 cancers of which 8007 were in women. There were 2673 female breast cancers, averaging 148 cases per year (Range:94-202). Almost half of cases (49.1%) were in women below the age of fifty. The mean age was:49.8 years +/- 13.9 years. Ten-year age groups distribution showed that 4.7% were below 30 years of age, 16.1% were 30-39 years, 28.3% were 40-49 years, 26.3% were 50-59 years, 16.9 % were 60-69 years, 6.1% were 70-79 years and 1.6% were 80 years of age or older. Twenty-two patients (0.9 %) had their age missing in the records. Overall ASR was 30.6, for a crude rate of 27.7. Age adjusted incidence rate had its peak in women aged 50-59, followed by women 40-49 then 60-69 with values of 96.3, 79.9 and 77.4 per 100,000 respectively. We also noted 19 male breast cancer cases corresponding to 0.7% of the 2692 combined total.

Conclusions: The percentage of women with breast cancer in Lebanon seen at AUBMC in pre-menopausal and younger-aged groups is higher than those reported from western countries. Our results emphasize the need to search for possible environmental, lifestyle and/or genetic risk factors in Lebanon. Our study also shows the importance of implementing early detection and screening programs which, along with high quality mammography and medical care, can have a positive impact on survival, especially in younger-aged women.