Graduation Date

Fall 12-16-2022

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Programs

Epidemiology

First Advisor

Evi Farazi, PhD

Second Advisor

Kendra L. Ratnapradipa, PhD

Third Advisor

Jane Meza, PhD

Fourth Advisor

Pavankumar Tandra, MBBS

Abstract

Despite increasing incidence, male breast cancer (MBC) remains understudied in almost all aspects of disease management. MBC patients are more likely to be diagnosed with larger tumors, at an advanced stage, and to experience poorer survival than female patients. There is a need to identify modifiable factors that can improve MBC patients’ survival.

This dissertation aimed to investigate whether there was a difference in the refusal of recommended treatments and related survival, by gender, in breast cancer patients enrolled in the National Cancer Database. Specifically, we conducted separate analyses for four treatments: hormone therapy, chemotherapy, radiation therapy, and surgery. Then, we evaluated associations between surgery refusal and survival and whether this association differed by gender. Finally, we investigated the associations between delayed surgery and overall survival and whether this association differed by gender.

Female patients tend to refuse hormone therapy and surgery, while males tend to refuse radiation therapy. Some factors, such as age 75 or above and insurance other than private, were associated with treatment refusal across all treatments—other factors, such as disease stage and race/ethnicity association with treatment refusal, varied by treatment type. Surgery refusal was associated with worse survival for both genders. Survival outcomes of breast cancer patients were negatively affected by a delay in surgery beyond 12 weeks, with a higher effect among males. Nevertheless, delaying surgery for shorter time periods tends to have a slightly protective effect in the combined sample of male and female patients, as well as among females alone.

Healthcare providers and other stakeholders can utilize the current findings to develop effective interventions addressing the known barriers associated with the refusal of each treatment, to enhance patients’ awareness, to improve patient-physician communication, and increase treatment acceptance rates to have a salutary effect on survival in both genders. Finally, clinicians can enhance male survival by ensuring the timeliness of receiving breast cancer surgery by structuring their practice to triage and initiating treatment promptly. Future qualitative studies are warranted to identify the root causes of treatment refusal and surgery delay at patient, patient-physician, and hospital levels.

Comments

2022 Copyright, the authors

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