Abstract PS1-04-18: Identifying Smoking-Related Factors in Breast Cancer Patients: Mayo Clinic Registry Insight

Abstract Background: Smoking, a known risk factor for numerous cancers, negatively impacts long-term survival in breast cancer (BC) survivors (Parada H Jr et al., 2017; Pierce et al., 2019). This study aims to characterize baseline smoking behaviors among breast cancer patients who self-reported smoking during an initial survey. Objectives: To assess attributes of patients self-reporting as current smokers near BC diagnosis, examining demographics, habits, quality of life, cancer treatments, comorbidities, and finances. Methods: Patients with newly diagnosed BC seen at Mayo Clinic Rochester between 2014-2024 were invited to enroll in the Mayo Clinic Breast Disease Registry. Consenting participants who completed self-reported questionnaires at baseline were included in this study. Smoking status and related variables at the time of survey completion were assessed via a baseline questionnaire, classifying participants as current, former, or never smokers. Of 3,959 participants completing baseline surveys, 3,729 were analyzed after excluding 103 with missing smoking data and 127 with their baseline survey returned >1-year post-diagnosis. Categorical variables were summarized with frequencies and percents, continuous variables with distributional statistics. Univariable associations with current smoking were assessed via two-sample t-tests (continuous) and chi-square or Fisher exact tests (categorical). Significant variables (p<0.05) were included in a multivariable logistic regression model. Results: Among 3,729 BC patients (mean age 58.3 years, SD 12.9), 99.1% were female, 97.1% White, and 98.7% non-Hispanic. Only 2.7% reported financial difficulty, 56.4% had a bachelor's degree or higher, 81.7% were married or equivalent, and 21.7% consumed ≥5 alcoholic drinks/week. Tumor stage distribution was as follows: Stage 0 (13.9%), Stage 1 (43.9%), Stage 2 (28.9%), Stage 3 (8.9%), and Stage 4 (4.5%); 33.8% received chemotherapy, 56.5% radiotherapy, 63.6% endocrine therapy, and 42.2% underwent mastectomy. Current smokers (2.6%, n = 95) had a median diagnosis age of 59.1 (IQR 31.8-87.1),with 32.6% consuming ≥5 drinks/week (vs. 21.5% in non-smokers, univariable p = 0.012), 69.5% with less than a Bachelor’s degree (vs. 42.9%, p<0.001), 9.6% facing financial difficulty (vs. 2.5%, p<0.001), and 10.5% diagnosed within 270-365 days after survey return (vs. 4.2%, p = 0.022). Tumor stage showed 47% with Stage 1 (vs. 43.7%, p = 0.245); 33.7% received chemotherapy, 60.0% radiotherapy, and 58.9% endocrine therapy. Current smokers had a mean smoking initiation age of 19.9 (SD 6.2), smoked 12.5 cigarettes/day (SD 7.9) for 32.8 years (SD 14.1), with mean 22.3 pack-years (SD 17.2).Univariable associations of demographic and clinical characteristics with current smoking showed Compared to never or former smokers, current smokers at the time of survey took a longer time to return their baseline survey (p = 0.022), were more likely to consume five or more alcoholic drinks per week (p = 0.012), were more likely to have difficulty paying their bills (p<0.001) and were less likely to obtain a Bachelor's degree or higher (p<0.001). These associations remained significant after multivariable adjustment. Conclusion: Current smoking (2.6%) soon after a BC diagnosis was independently associated with delayed survey return, higher alcohol use, financial difficulty, and lower education. Assessing smoking status and referring patients to smoking cessation programs are critical for addressing these risk factors and improving health outcomes. These findings highlight distinct socioeconomic and behavioral profiles among current smokers, suggesting potential targets for tailored interventions. Citation Format: S. Hirani, R. A. Vierkant, N. L. Larson, S. D. D’Andre, F. J. Couch, J. E. Olson, K. J. Ruddy. Identifying Smoking-Related Factors in Breast Cancer Patients: Mayo Clinic Registry Insight [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-04-18.