Although female breast cancer remains relatively rare in Korea, its incidence and mortality have been rising quite rapidly. In this study, we estimated the probability of developing breast cancer, and examined the trend of its incidence using the proportion of cases with breast cancer among the total female cancer cases in the Korean Central Cancer Registry.

The probability of developing breast cancer was estimated for Korean women using a method based on the cumulative risk. The number of future breast cancer cases for the year 2020 was estimated by extrapolating the secular trend of the proportions of those with breast cancer between 1995 and 2002, using a logistic regression model.

With an expected average life span of 84 years, Korean female has a 2.36% chance of developing breast cancer during her lifetime. The predicted expected age-adjusted proportions of breast cancer among the total female cancer cases were 19.5, 24.3, 29.9 and 36.1% for the years 2005, 2010, 2015 and 2020, respectively. The predicted expected crude proportions for the same years were 17.4, 19.7, 21.7 and 23.4%, respectively. The expected number of breast cancer cases to the 2020 would be 19,791, which is at least five times than that in 1996.

Based on our results, female breast cancer in Korea will increase further and cumulative rate of breast cancer is highest at 40s and 50s. Lifestyle modification and prevention strategy especially for younger or high risk women might be essential to reduce breast cancer incidence.