Real-World Data on the Prevalence of Anaplastic Lymphoma Kinase-Positive Non-Small-Cell Lung Cancer in the Middle East and North Africa.

Abstract

Anaplastic lymphoma kinase (<i>ALK</i>) gene alterations are potent oncogenic drivers in non-small-cell lung cancer (NSCLC). Tyrosine kinase inhibitors targeting the ALK pathway are effective in treating <i>ALK</i>-positive NSCLC. Around 5% of Asian and White patients with NSCLC have <i>ALK</i>-positive tumors, but <i>ALK</i> rearrangement prevalence data in the Middle East and North Africa (MENA) region are limited. In this noninterventional epidemiology study, histologically confirmed nonsquamous NSCLC samples retained for < 5 years in tissue banks at six centers in MENA were retrospectively analyzed for <i>ALK</i> rearrangement using the VENTANA immunohistochemistry (IHC) method. Patient characteristics obtained were analyzed for association with <i>ALK</i> rearrangement. Concordance between IHC and Vysis fluorescence in situ hybridization (FISH) ALK detection methods was assessed in a subset of samples. Four hundred forty-eight tissue samples were analyzed using IHC: 137 (30.6%) in Lebanon, 104 (23.2%) in Saudi Arabia, 97 (21.7%) in Egypt, 80 (17.9%) in the United Arab Emirates, and 30 (6.7%) in Morocco. On the basis of IHC, the prevalence was 8.7% (95% CI, 6.3 to 11.7) for <i>ALK</i>-positivity and 91.3% (95% CI, 88.3 to 93.7) for <i>ALK</i>-negativity. On the basis of FISH (n = 148), the prevalence was 5.4% positivity and 81.8% negativity (12.8% nonevaluable). Concordance between IHC and FISH (n = 129) was 98.4% (95% CI, 94.2 to 99.8) for negative agreement and 98.5% (95% CI, 94.5 to 99.8) for overall agreement. Univariate analysis showed that <i>ALK</i> rearrangement was significantly associated with epidermal growth factor receptor wild-type status (<i>P</i> = .03) but was not significantly associated with sex, race, smoking history, or histologic subtype. Our findings suggest that <i>ALK</i> rearrangements are more prevalent in MENA than other geographic regions. High concordance was found between FISH and IHC. Except for epidermal growth factor receptor wild-type status, no clinicopathologic characteristics were associated with <i>ALK</i>-positive NSCLC.