Racial/ethnic differences in incidence of squamous cell carcinoma in California.

Abstract

11139 Background: Squamous cell lung carcinoma is strongly associated with a history of smoking. Typically, no actionable mutations are found, and treatment options are more limited. It is not known if race has any impact on the incidence of squamous cell cancers, especially for Asian ethnicities since most studies combine multiple Asian populations in an Asian/Pacific Islander (API) category. The purpose of this study was to compare the odds of squamous cell carcinoma versus adenocarcinoma in Hispanic, American Indian, Middle Eastern, and 7 Asian ethnicities when compared with both Black and White men and women. Methods: We accessed 211,987 cases of invasive lung cancer with either squamous cell or adenocarcinoma from the California Cancer Registry 2000-2020. Race was categorized as White, African American/Black, Hispanic, American Indian/Alaskan Native, Middle Eastern, Chinese, Japanese, Korean, Filipino, Southeast Asian (SEA), Pacific Islander, or Asian Indian. Separate logistic regression analyses were used to assess the odds of squamous cell versus adenocarcinoma for each race/ethnicity using White and Black as the reference categories. Analyses were conducted separately for males and females and adjusted for age, smoking status, socioeconomic status, marital status, and Charlson Comorbidity Score. Odds Ratios (OR) and 95% confidence intervals (CI) were computed. Results: When compared with White men, American Indian men had increased odds (OR: 1.39; 95% CI: 1.03, 1.88) and Black, Hispanic, Chinese, Filipino, SEA men had decreased odds of squamous cell carcinoma. Japanese women had increased odds (OR: 1.54; 95% CI: 1.15, 2.07) while Black, Hispanic, Middle Eastern, Filipino, and SEA women had decreased odds of squamous cell carcinoma when compared with White women. When compared with Black men, White men, (OR: 1.11; 95% CI: 1.01, 1.24) American Indian, (OR: 1.56; 95% CI: 1.13, 2.13) and Korean (OR: 1.35; 95% CI: 1.05, 1.73) men had increased odds and Chinese, Filipino, and SEA men had decreased odds of squamous cell carcinoma. White, (OR: 1.13; 95% CI: 1.01, 1.28) Japanese, (OR: 1.75; 95% CI: 1.28, 2.39) and Korean (OR: 1.63; 95% CI: 1.09, 2.42) women had increased odds and Southeast Asians had decreased odds when compared with Black women. Conclusions: Some Asian ethnicities have a higher risk for squamous cell lung cancer than both Black and White men and women even after adjusting for smoking. This is not apparent when the Asian ethnicities are classified as API. Examining individual Asian ethnicities is important since they have little to no shared genetic or cultural variables and are grouped together for convenience rather than any scientifically plausible reason.