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.