Low Rates of Medical Oncology Consultation for Older Women (≥ 70 Years) with Newly Diagnosed, Non-Metastatic Breast Cancer: A Population-Based Study

Background Curative intent cancer treatment needs to be balanced with patient comorbidities and quality of life when treating older women with breast cancer. We examined consultation patterns and association of age at diagnosis with lack of specialist cancer consultations for older women with breast cancer. Methods We conducted a population-based retrospective cohort study of older women (≥ 70 years of age) with incident, non-metastatic breast cancer (2010–2018) by linking administrative databases in Ontario, Canada. The outcomes of interest were lack of specialist cancer consultation (surgeon, medical oncology, or radiation oncology) within 12 months of diagnosis. Association of age with lack of specialist cancer consultation was examined using Poisson regression modeling. Results Of 21,849 older women, 2.4% ( n = 517) did not have any specialist cancer consultation within 12 months of diagnosis; lack of any specialist cancer consultation increased with age (0.8% for age 70–74 years, 1.3% for age 75–79 years, 2.5% for age 80–84 years, and 7.0% for age ≥ 85 years; p < 0.001). The proportion of patients who did not have consultations with surgeons, medical oncologists, and radiation oncologists was 8.6% ( n = 1888), 34.4% ( n = 7510), and 24.7% ( n = 5404), respectively. Older age group was independently associated with an increased likelihood of lacking any specialist consultation, as well as not receiving surgical and medical oncology consultations. Conclusion More than one-third of women ≥ 70 years of age with non-metastatic breast cancer did not have a consultation with a medical oncologist, with women aged ≥ 85 years least likely to have a medical oncology consultation.