Comparison of the relative incidence of impalpable invasive breast carcinoma and ductal carcinoma in situ in cancers detected in patients older and younger than 50 years of age

PURPOSE: To compare the relative incidence of impalpable ductal carcinoma in situ (DCIS) and invasive breast carcinoma detected mammographically in women younger than 50 years of age and those aged 50 years and older. MATERIALS AND METHODS: Needle-wire localization and surgical biopsy were performed in 4,428 impalpable lesions in 3,734 patients. A total of 1,179 breast cancers were found. Histologic findings were reviewed retrospectively, and lesions were classified as invasive cancer or DCIS. The patients were categorized into two groups: those aged 50 years and older and those younger than 50 years of age. RESULTS: A total of 294 cancers were found in women younger than 50 years of age. Of these cancers, 137 (46.6%) were DCIS and 157 (53.4%) were invasive. In women aged 50 years and older, 885 cancers were found. Of these, 325 (36.7%) DCIS and 558 (63.1%) invasive cancers were found. CONCLUSION: For mammographically detected breast carcinomas, there is a higher relative incidence (46.6% vs 36.6%) of DCIS in the younger age group, which may lend further support for aggressive screening of women younger than 50 years of age.