Adjuvant treatment decisions among women age > 65 with early-stage, hormone-receptor breast cancer seen in multidisciplinary clinic versus standard consultation.

281 Background: Randomized studies and national guidelines support de-escalation of adjuvant therapy for a target population of woman >65 years with Stage I, ER positive breast cancer after breast conserving surgery. We sought to evaluate the impact of a multidisciplinary clinic (MDC) in this population by comparing treatment patterns and patient perceptions of adjuvant radiation therapy (RT) and hormone therapy (HT) between patients seen in MDC vs. standard consultation. Methods: Medical records were retrospectively reviewed for women in the above target population who underwent surgery between 8/2020- 5/2022at our institution. Two cohorts were included: (1) patients seen in MDC, and 2) patients seen in standard clinic separately by medical and radiation oncology (non-MDC cohort). The non-MDC patients declined, could not attend, and/or were not referred to the MDC. Patients in the MDC cohort were prospectively administered validated questionnaires to evaluate patient reported data including the Decision Autonomy Preference Scale (DAPS), e-Prognosis, and Medical Maximizing-Minimizing Scale (MMS). Chi square, t-tests, and non-parametric equivalents compared demographics and logistic and linear regression evaluated RT and HT use and survey score outcomes between cohorts. Results: A total of 128 patients met inclusion criteria, with 33 MDC and 94 non-MDC patients. There was no difference between the cohorts in age, margin status, histology, grade, or focality. In the MDC cohort there were significantly fewer sentinel lymph node biopsies (42.4% vs. 71.3%, p = 0.003) and mean tumor size was smaller (0.69 vs. 0.96 cm, p < 0.003). There was no significant difference in receipt of RT (65% MDC vs 77% standard; OR = 0.55, p = 0.189, HT (78% MDC vs 72% standard; OR = 1.36, p = 0.534), or both (65% MDC vs 77% standard; OR = 0.7, p = 0.430). The MDC cohort was significantly more likely to undergo accelerated (vs. standard hypofractionated) RT (70% vs 39%; OR = 3.60, p = 0.020). In MDC patients with completed questionnaires (n = 33), by DAPS, all “mostly patient (n = 8)” chose RT while all “mostly doctor (n = 1)” chose no RT (p = 0.063). Based on e-Prognosis, there were lower odds of RT for increasing Schonberg score/ higher 10yr mortality risk (OR 0.600, p = 0.048). MIMS score > 40 (“maximizer”) was strongly correlated with the use of RT (OR 18.57, p = 0.011). Conclusions: For women > 65 years with early stage, ER positive breast cancer, MDC participation was not associated with lower use of adjuvant RT or HT versus standard consultation but was significantly associated with shorter RT courses. DAPS and MMS results indicate that patient treatment preference may be predictable, highlighting an opportunity to tailor consultation discussions and recommendations based on intrinsic patient preferences and individual goals.