Abstract 6111: Real world incidence of ALK alterations in Hispanic NSCLC patients in Los Angeles
Authors: Hsu Robert C. , Poei Darin , Thomas Jacob S. , Nieva Jorge J. 
Published: March 2024

Introduction: Race and ethnicity affect the distribution of molecular alterations seen in populations of lung cancer patients. ALK fusions occur in 4-5% of non-small cell lung cancer (NSCLC) patients overall. We characterized ALK alteration presence in NSCLC Hispanics treated at a large academic institution in Los Angeles. Methods: 607 NSCLC patients treated at Los Angeles General Medical Center (LAGMC) (n=174) and Norris Comprehensive Cancer Center (NCCC) (n=433) who received comprehensive genomic profiling (CGP) were evaluated from July 2017 to June 2023. Fisher’s exact test was done to compare differences in prevalence between Hispanics and non-Hispanics. Multivariate logistic regression was performed to evaluate the role of Hispanic ethnicity controlling for site of treatment, age at initial diagnosis, sex, and smoking history. Results: Hispanics represented 23% (n=141) and 7.2% of patients (n=44) had ALK alterations (Table 1). Hispanics (12.76%, n = 18/141) were more likely to have ALK alterations than Non-Hispanics (5.58%, n = 26/466) (p=0.0083). In 18 Hispanic ALK patients, the median age was 53 years, 50% female (n=9), and 61.11% never smokers (n=11) versus a median age of 62.1 years, 46.80% female (n=66), and 53.19% never smokers (n=75) in all Hispanics (n=141). 94.44% of ALK Hispanics (n=17) were diagnosed as Stage IV versus 72.34% (n=102) in all Hispanics. Brain metastasis was seen in 61.11% (n=11) of Hispanic ALK patients versus 33.33% (n=47) in all Hispanics. Multivariate logistic regression showed Hispanic ethnicity HR 2.338 (95% CI 1.105-4.907) and age at diagnosis HR 0.9275 (95% CI 0.9025-0.9519) were significant variables in ALK alteration incidence. Conclusions: Hispanics represented 23% of the NSCLC population tested for CGP but 41% of the ALK altered patients. This highlights the need to study Hispanic ethnicity in the biology of ALK alterations, ensure Hispanics have equal access to CGP, and greater Hispanic representation in ALK inhibitor clinical trials.

Clinical Characteristics of NSCLC patients at LAGMC and NCCC receiving CGP Hispanic Asian Non-Hispanic Black Non-Hispanic White Other/Unknown Total Number of ALK alterations (%) 18 (12.76%) 9 (4.41%) 0 (0.00%) 15 (8.24%) 2 (4.44%) 44 (7.2%) Total Population 141 204 35 182 45 607 Median Age of Diagnosis ALK population 53 52 - 55 51.5 53 Total population 62.1 66.1 63.6 68.4 65.6 65.7 Sex Females in ALK population (%) 9 (50.00%) 5 (55.56%) - 8 (53.33%) 1 (50.00%) 23 (52.27%) Females in total population (%) 66 (46.80%) 105 (51.47%) 14 (40.00%) 89 (48.90%) 20 (44.44%) 294 (48.43%) Smoking History Never smoker in ALK population (%) 11 (61.11%) 7 (77.78%) - 10 (66.67%) 1 (50.00%) 29 (65.90%) Never smoker in total population (%) 75 (53.19%) 122 (59.80%) 8 (22.86%) 55 (30.22%) 18 (40.00%) 278 (45.80%) Histology Adenocarcinoma in ALK population (%) 17 (94.44%) 7 (77.78%) - 14 (93.33%) 0 (0.00%) 38 (86.36%) 114 (80.85%) 161 (78.92%) 25 (71.43%) 121 (66.48%) 30 (66.67%) 451 (74.30%) Stage Stage IV at diagnosis in ALK population (%) 17 (94.44%) 7 (77.78%) - 13 (86.67%) 2 (100.00%) 39 (88.64%) Stage IV at diagnosis in total population (%) 102 (72.34%) 113 (55.39%) 16 (45.71%) 95 (52.20%) 22 (48.89%) 348 (57.33%) Brain Metastasis Brain metastasis in ALK population (%) 11 (61.11%) 2 (22.22%) - 8 (53.33%) 2 (100.00%) 23 (52.28%) Brain metastasis in total population (%) 47 (33.33%) 57 (27.94%) 10 (28.57%) 38 (20.88%) 6 (13.33%) 158 (26.0%)

Citation Format: Robert C. Hsu, Darin Poei, Jacob S. Thomas, Jorge J. Nieva. Real world incidence of ALK alterations in Hispanic NSCLC patients in Los Angeles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6111.