J. Den1, N. Nelson1, V.S. Klimberg1 1University Of Texas Medical Branch, General Surgery, Galveston, TX, USA
Introduction:
Schizophrenia is a devastating disease and is believed to increase breast cancer (BC) risk. The aim of our project was to evaluate the incidence of breast cancer in women with schizophrenia and to compare outcomes between breast cancer patients who were or were not on antipsychotics prior to diagnosis.
Methods:
This study used TriNetX to evaluate the incidence and trend of breast cancer in schizophrenia by age and ethnicity from 2011-2022. Data was queried for women ≥18 years diagnosed with schizophrenia. The event of interest was the diagnosis of breast cancer. 1,398,475 patients were identified.
We also assessed the impact of antipsychotics on breast cancer outcomes. The analytics subset included 126,688 women ≥18 years who used antipsychotics one year before breast cancer diagnosis, and 592,837 who did not. Propensity matching was conducted using age, obesity, tobacco use, socioeconomic status, cancer stage, chemoradiation, axillary lymph node dissection (ALND), sentinel lymph node biopsy (SLNB), and hormone therapy use. Outcomes of interest were mortality, recurrence, chemotherapy need, and lymphedema.
Results:
Breast cancer incidence in schizophrenic patients was stable from 2011-2022 (0.53%). Non-Hispanic patients (0.57%) showed higher risk of BC than Hispanic patients (0.43%). Most patients were aged 60-70.
The outcomes study included 91,531 matched patients. Cohort 1 contained women ≥18 years old who were on antipsychotics before breast cancer diagnosis, and Cohort 2 included those who had never been on antipsychotics prior to cancer diagnosis. Cohort 1 exhibited higher risk of mortality (17.9% vs 12.8%, p<0.0001), recurrence (22.6% vs 13.4%, p<0.0001), chemotherapy need (48.4% vs 41.2%, p<0.0001), and lymphedema (11.5% vs 7.7%, p<0.0001).
Conclusion:
Breast cancer incidence in schizophrenic patients remained stable over the past decade. Non-Hispanic patients with schizophrenia were diagnosed with breast cancer approximately 1.3 times higher than Hispanic patients with schizophrenia. Matched breast cancer patients on antipsychotics at least one year prior to diagnosis had higher mortality, recurrence, and chemotherapy need. Antipsychotics are significantly associated with the development of lymphedema in breast cancer, which is a new finding that has not been described in literature.