Background: The authors' aims were to define the frequency, characteristics, and methods of detection of breast masses in young women treated for childhood cancer and to develop screening guidelines for the growing population of long term survivors.
Methods: The authors reviewed medical records of all female patients treated for malignancy at a childhood cancer center over a 34-year period to identify those who developed a breast mass and to determine the cumulative incidence of breast cancer as a second primary cancer.
Results: A breast mass was identified in 66 patients who had been diagnosed with a malignancy at a median age of 13.8 years (range, 0.4-24.4 years). Masses were initially detected by breast self-detection in 32 and clinical examination in 28; the method of detection was unknown in 6 cases. Breast lesions were benign in 41 patients and malignant in 26; 1 patient had both a benign and a malignant lesion. Of the 26 malignant masses, 14 represented metastases of the primary malignancy and 12 were primary breast cancers as second primary cancers. The median interval to a primary breast cancer as a second primary cancer was 13.6 years (range, 9.2-24.4 years), and the median age at detection was 27.7 years (range, 12.5-43.1 years). The 25-year cumulative incidence of primary breast cancer as a second primary cancer in this cohort was 1.7% (95% CI, 0.4%-2.9%). This represented a 20-fold increase (95% CI, 10-36) over the expected incidence in age-matched and race-matched controls.
Conclusions: Young women treated for childhood cancer have a significantly increased risk of breast cancer compared with age-matched controls. For this group of patients, the authors recommend patient education regarding this risk and the importance of properly conducted self-examination as the foundation of breast cancer screening. In addition, clinical and mammographic screening should be instituted at a younger age and performed more frequently than recommended for the general population of women.