Investigation of racial differences in survival from non-small cell lung cancer with immunotherapy use: A Texas study

Abstract

Background: The use of immunotherapy is associated with improved survival among patients with Non-Small Cell Lung Cancer (NSCLC) and has gained widespread use in its management. However, there is limited information on whether the survival benefits associated with immunotherapy differ among races and ethnicities.

Objective: This study aimed to investigate racial differences in survival amongst patients with NSCLC who received immunotherapy as the first-line treatment in Texas.

Methods: Patients with NSCLC who received immunotherapy between October 2015 to December 2018 were identified from the Texas Cancer Registry (TCR). Disease-specific survival was evaluated and compared among patients across racial/ethnic categories using the Kaplan-Meier survival analysis, log-rank test, and a multivariable Cox proportional hazard regression model following an inverse probability treatment weighting (IPTW) propensity score analysis.

Results: A total of 1453 patients were included in the analysis. Median survival (in months) was longest among Asians (34, 95% CI: 15-Not Estimable), followed by African Americans (AAs) (23, 95% CI: 15-34), Hispanics (22, 95% CI: 16-26), and Whites (19, 95% CI: 17-22). The adjusted regression estimates had no statistically significant differences in survival among AAs (aHR = 0.97; 95% CI = 0.78-1.20; P =0.77) and Hispanics (aHR = 0.96; 95% CI = 0.77-1.19, P =0.73) when compared to White patients. Asians on the other hand, had 40% reduction in mortality risk compared to Whites (aHR = 0.60; 95% CI = 0.39-0.94, P = 0.03).

Conclusions: Our study indicated that African Americans and Hispanics do not have poorer survival compared to White patients when receiving immunotherapy as first-line treatment. Asians however had longer survival compared to Whites. Our findings suggest that existing racial disparity in NSCLC survival might be mitigated with the use of immunotherapy and should be considered in providing care to these minority groups.

Keywords: immunotherapy; non-small cell lung cancer; racial disparity; retrospective study; survival analysis.

Figure 1

Consort diagram showing cohort selection: Patients 18 years and older with histologically confirmed cases of non-small cell lung cancer who received immunotherapy as the first treatment course between October 1, 2015, and December 31, 2018.

Figure 2

Kaplan-Meier curves showing disease-specific survival in patients with non-small cell lung cancer who received immunotherapy as the first course of treatment in Texas from 2009 to 2018. From L to R: (A) the entire cohort; (B) patients stratified by race and ethnicity; and comparisons between (C) African American and White patients, (D) Hispanic and White patients, and (E) Asian and White patients.

Figure 3

Forest plot of multivariable Cox proportional hazard regression analysis showing the association between patient characteristics and disease-specific survival using regression adjustment.

Figure 4

Histogram showing the distribution of propensity scores by treatment (racial) group. From L to R: stacked histogram showing individual propensity scores for treatment groups, the overlap of propensity scores among treatment groups.

Figure 5

Forest plot of multivariable Cox proportional hazard regression analysis showing the association between patient characteristics and disease-specific survival using the inverse probability treatment weighting (IPTW) method.