Chronic disease outcomes among South Asian cancer survivors.
Authors: Gowda Karan , Chen Po-Hua , Kim Rachel , Leonard Myisha , Carnethon Mercedes , Lancki Nicola , Hibler Elizabeth A. 
Published: June 2023

e24098 Background: Although racial and ethnic disparities in cancer survivorship are widely known, the understanding of cancer survivorship among South Asian patients is limited, especially in the United States. Previous studies identified significant health-related disparities within the wider Asian diaspora, however, less is known among Asian subgroups. Thus, we conducted a study examining the differences in chronic disease outcomes between South Asian cancer survivors compared to other races/ethnicities. Methods: We used a name list algorithm to identify South Asian patients among cancer survivors treated at Northwestern Medicine between 2005-2020. After patients were identified, we conducted chi-square tests and logistic regression (adjusting for age and gender) to evaluate variation in prevalence of chronic diseases including diabetes mellitus, hypertension, coronary heart disease, and more. Racial and ethnic comparisons were done using the self-reported race fields within the Northwestern Medicine database. Results: The algorithm identified 1,217/102,579 (1.2%) South Asian patients. We found that 49% self-identified as Asian, 18% as White or Caucasian, 17% as Other, and 9.7% as ‘Declined or Unable to Answer’. The self-reported racial comparison groups used were Asian (not South Asian) (n = 2,631, 2.6%), Black (n = 9,350, 9.4%), and White (n = 75,252, 75%). We found that South Asian patients had a higher frequency of leukemia, lymphoma, kidney, and multiple myeloma cancers and a lower frequency of lung, colorectal, liver, cervical, and thyroid cancers compared to Asian (not South Asian) patients (p < .05). We also found the average baseline BMI is greater in South Asians (mean = 26.2, SD = 4.7) compared with Asians (mean = 24.7, SD = 4.4) (p < .05). From the logistic regression models, South Asian cancer survivors had higher odds of diabetes compared with White cancer survivors (OR 1.93 [95% CI 1.50-2.49]). In contrast, the odds of coronary heart disease, hypertension, and heart failure were lower among South Asian compared to Black cancer survivors (0.69 [95% CI 0.53-0.92]; 0.57 [95% CI 0.48-0.68]; 0.49 [95% CI 0.37-0.65], respectively). The odds of atrial fibrillation were lower among South Asian compared to Asian (not South Asian), White, and Black patients (0.59 [95% CI 0.41-0.86]; 0.46 [95% CI 0.34-0.64], 0.58 [95% CI 0.42-0.80], respectively). We did not identify statistically significant associations for these chronic diseases with the other racial groups. Conclusions: These results show there are differences for cancer survivors who were identified as South Asian compared with other groups, even other Asian patients. Analysis of racial and ethnic differences in chronic disease risk among cancer survivors is necessary for understanding the full scope of cancer survivorship. Further understanding the health disparities that exists among the Asian subgroups is important to advancing cancer care for patients from every demographic.