Abstract PO3-22-08: Impact of Zip Code-Based Income on Reconstructive Method and Outcomes in Mutation-Positive Breast Cancer Patients
Authors: Gupta Jaytin , Sortur Shrayus , Lava Christian , Lee Margaret , Berger Lauren , Harish Varsha , Spoer Daisy , Rosal Lindy , Greenwalt Ian , De La Cruz Lucy , Song David , Fan Kenneth 
Published: May 2024

Background: In the United States, 13% of women develop invasive breast cancer, with certain genetic mutations increasing the risk. Genetic screening is costly and burdensome for patients, particularly those from lower socioeconomic backgrounds. Moreover, lower income (LI) patients face barriers in accessing healthcare and have lower rates of breast reconstruction. This study aims to examine the impact of socioeconomic status, as indicated by ZIP code median income, on the type of breast surgery, reconstructive technique, and perioperative outcomes among mutation-positive (M+) patients.

Methods: A multicenter retrospective cohort study included patients with a genetic predisposition for breast cancer and undergoing breast and reconstructive surgery between January 2016 and October 2022. Patient demographics, history, operative details, and postoperative outcomes were collected. Patient ZIP codes were cross-referenced with the American Community Survey to determine the median household income, which served as a proxy for the patient-specific household income. Four distinct income quartiles were established: quartile 1 (Q1) = $37,045-$81,586 (“LI”); quartile 2 (Q2) = $81,587-$103,703; quartile 3 (Q3) = $103,704-$129,768; and quartile 4 (Q4) = $129,769-$213,724.

Results: Among the 170 patients analyzed, 42 (24.7%) were in Q1, 42 (24.7%) in Q2, 44 (25.9%) in Q3, and 42 (24.7%) in Q4. Most patients had BRCA1 (n=73, 42.9%), BRCA2 (n=68, 40.0%), PALB2 (n=11,6.5%), or CHEK2 (n=8, 64.7%) mutations, and underwent prophylactic mastectomy without evidence of breast cancer (n=119, 70.0%). Mean age and body mass index (BMI) were 41±16 years and 25.0±7.5 kg/m2, respectively. There was a significant association between patient race and income (p&lt; 0.0001), such that 30.1% of White patients were in Q4 (vs. 8.3% of Black patients), compared to 38.9% of Black patients in Q1 (vs.19.0% of White patients). LI was significantly associated with higher BMI (p=0.0083) and obesity rates (p=0.0080). Nipple-sparing mastectomy (NSM) (n=103, 60.6%) was the most frequent surgical approach, followed by skin-sparing mastectomy (SSM) (n=42, 24.7%), simple mastectomy (n=13, 7.6%), lumpectomy (n=4, 2.4%), and radical mastectomy (n=4, 2.4%). Patients in Q3 underwent NSM significantly more often than those in Q1 (p=0.0080). Tissue expander (n=73, 42.9%) was the most common reconstruction method. 34.7% of patients (n=59) experienced postoperative complications. Short-term (&lt; 30 days postoperatively) complications included delayed wound healing (n=22, 12.9%), surgical site infection (n=16, 9.4%), dehiscence (n=12, 7.1%), cellulitis (n=10, 5.9%), seroma (n=9, 5.3%) and hematoma (n=9, 4.7%). Long term (≥30 days postoperatively) complications included mastectomy flap necrosis (n=22, 12.9%), total reconstructive failure (n=8, 4.7%), and red breast syndrome (n=2, 1.2%). There was no significant association between income level and incidence of complications (p &gt;0.05). Income level significantly correlated with cancer recurrence, as patients in Q2 (n=0, 0.0%) and Q4 (n=1, 2.4%) had significantly lower recurrence rates compared to Q1 (n=6, 14.3%) (p=0.0140). Of the 30.0% of patients with diagnosis of cancer at DOS, 66.7% (n=34) of patients had ductal carcinoma in situ (DCIS). Eleven of these patients were in Q1, five in Q2, six in Q3, and twelve in Q4 (p=0.259).

Conclusion: LI M+ patients had lower NSM rates than higher income patients, despite similar rates of prophylactic mastectomies, possibly due to perceived costs of increased follow-up care. Moreover, LI patients experienced higher cancer recurrence, despite similar incidences of equivalent cancer subtypes at presentation, likely reflecting differences in post-diagnostic care and morbidity. These findings highlight the need to address financial barriers and ensure equitable access to comprehensive care for M+ patients of all income strata.

Citation Format: Jaytin Gupta, Shrayus Sortur, Christian Lava, Margaret Lee, Lauren Berger, Varsha Harish, Daisy Spoer, Lindy Rosal, Ian Greenwalt, Lucy De La Cruz, David Song, Kenneth Fan. Impact of Zip Code-Based Income on Reconstructive Method and Outcomes in Mutation-Positive Breast Cancer Patients [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO3-22-08.