Historical redlining and oral squamous cell carcinoma staging at diagnosis.

e22598 Background: Previous research has shown that residents in historically redlined zones, areas defined from the discriminatory housing policy in 1935-1940, are more prone to being diagnosed with later-stage cancer for breast cancer, cervical cancer, lung cancer, colorectal cancer, and prostate cancer. However, little was known about this relationship for oral squamous cell carcinoma, which lacks general screening guidelines at primary care settings and general practice incorporating oral cancer screening during routine dental care. Methods: We used cancer registry data from a single tertiary medical center mainly from year 2016-2025 to identify patients diagnosed with primary oral squamous cell carcinoma. Main exposure is whether the patient resided in historically redlining zone, defined as Homeowners’ Loan Corporation (HOLC) grades C and D. Main outcome of interest is the stage of oral squamous cell carcinoma, which is grouped as the binary outcome (late stages stage III, IV vs early stages stages I, II). Logistic regression is used to study the association between redlining and being diagnosed with late-stage oral squamous cell carcinoma. The data was visualized by a map incorporating the redlining zone and stages of oral squamous cell carcinoma at diagnosis. R version 4.2.3 is used for statistical analysis. Results: Among 566 patients diagnosed with primary oral squamous cell carcinoma, 232 (41%) are female, 105 (19%) are black/African American, and 39 lived in the historically redlining zone. The median age at diagnosis was younger among patients from redlined zones (median IQR: 59.81 52.01, 63.84 ) compared to those from non-redlined zones (median IQR: 65.7 57.94, 74.28 (p = 0.001). The unadjusted odds of a late-stage diagnosis were higher for patients in historically redlined zones (OR = 2.51, 95% CI = 1.18, 5.59). Findings were similar after adjusting for sex, age, and smoking status(OR = 2.38, 95% CI = 1.11, 5.71). Conclusions: The findings suggest that patients living in historically redlining zones are more likely to receive a late-stage diagnosis of oral squamous cell carcinoma and to be diagnosed at a relatively younger age. Findings indicate a need to increase resources, including increased dental care, in these areas to help identify cancers at an earlier stage and reduce disparities in oral squamous cell carcinoma outcomes. Further research and potential policy and/or public health initiatives targeting these populations for risk reduction and screening are warranted. Association between residing in historical redlining zone and odds of being stage III/IV oral squamous cell carcinoma at diagnosis. OR (95% CI ) Model 1: Unadjusted 2.51 1.18, 5.95 Model 2: Adjusted for age 2.49 1.17, 5.94 Model 3: Adjusted for age, sex 2.49 1.17, 5.95 Model 4: Adjusted for age, sex, smoking status 2.38 1.11, 5.71 OR = odds ratio; CI = confidence interval.