Incidence and treatments of DCIS in octogenarians: grade matters

Purpose The purpose of this study is to better characterize the current incidence and treatment patterns of DCIS in women greater than 80 years of age (> 80) and to evaluate the effect of grade on treatment efficacy. Methods Retrospective observational study of women diagnosed with single primary DCIS from 2000 to 2012 in SEER. Statistics including incidence, multivariable Cox proportional hazards model and subset analysis were performed. Results 42,899 female patients with DCIS were identified, 2566 (5.98%) were > 80. Incidence of DCIS in the less than 80 (< 80) cohort was 8 per 100,000 and 11.7 per 100,000 for > 80. > 80 patients have a similar incidence of high grade DCIS (9.8%) as compared to < 80 cohort (10.7%, P = 0.246). Compared to the < 80 population the > 80 population received significantly less surgery (97 vs. 92%, P < 0.001) and radiation (22 vs. 47%, P < 0.001). Although on multivariate analysis surgery did not provide a survival benefit for > 80 population, it conveyed a survival benefit for high grade DCIS (HR 0.14, 95% CI 02-0.68) that was not observed for low grade DCIS (HR 0.46, 95% CI 0.1-2.03). Conclusions Patients over 80 years of age have a relatively high incidence of DCIS and receive low relative rates of treatment. Although surgery does not provide a survival benefit for all patients over 80, it does provide a significant survival benefit for patients with high grade DCIS. Our results suggest that perhaps the biology of the DCIS, not the age of the patient should direct who warrants treatment.