Ductal carcinoma in situ in the elderly: what is the ideal treatment plan?

Aim: To evaluate the association between local-regional treatment strategies on overall survival (OS), we compared elderly patients with ductal carcinoma in situ (DCIS) who underwent lumpectomy alone vs. lumpectomy + radiation or mastectomy. Methods: Patients ≥ 70 years in the National Cancer Data Base (2004-2015) with DCIS who underwent lumpectomy or mastectomy were selected. Kaplan-Meier curves were used to visualize the unadjusted OS. A Cox proportional hazards model was used to estimate the effect of local-regional treatment on OS after adjustment. Separate subgroup analyses were conducted for grade 1, estrogen receptor positive (ER+), and low-volume (< 3 cm) disease. Results: 18,451 patients met inclusion criteria (n = 13,284 lumpectomy + radiation or mastectomy; n = 5,167 lumpectomy alone). The unadjusted 10-year OS was 54% for the entire cohort. After adjustment, patients who underwent lumpectomy + radiation or mastectomy had a slightly improved OS (vs. lumpectomy alone; HR = 0.841, 95%CI: 0.774-0.914). For patients with grade 1 disease, lumpectomy + radiation or mastectomy was not associated with an improved OS (P = 0.12). For patients with ER+ disease, (lumpectomy + radiation or mastectomy) + endocrine therapy yielded the most significant improvement in OS (HR = 0.669, 95%CI: 0.598-0.748). Among patients with low-volume disease, lumpectomy + radiation or mastectomy was associated with an improved OS (HR = 0.812, 95%CI: 0.725-0.91). Conclusion: Our data suggest that chronologic age alone should not preclude a patient from receiving standard therapy for DCIS, while patient fitness, competing comorbidities, and patient preferences are critical factors to consider in light of potentially limited benefits of treatment. In favorable cancer diagnoses such as DCIS, thoughtful omission of standard therapy may be considered.