Supplementary Material for: Molecular Epidemiology of <b><i>ALK</i></b> Rearrangements in Advanced Lung Adenocarcinoma in Latin America
2018-11-26T10:48:04Z (GMT) by
<b><i>Objective:</i></b> Latin American countries are heterogeneous in terms of lung cancer incidence and exposure to potential carcinogens. We evaluated the frequency and clinical characteristics of <i>ALK</i> rearrangements (<i>ALKr</i>) in Latin America. <b><i>Methods:</i></b> A total of 5,130 lung cancer patients from 10 Latin American countries were screened for inclusion. <i>ALKr</i> detection was performed by fluorescence in situ hybridization (FISH), immunohistochemistry (IHC), and real-time reverse transcriptase-polymerase chain reaction (RT-PCR) to assess method variability. Demographic and clinicopathologic characteristics were analyzed. <b><i>Results:</i></b> Among the 5,130 patients screened, 8.4% (<i>n</i> = 433) had nonevaluable FISH tests. Evaluable FISH analyses revealed positive <i>ALKr</i> in 6.8% (320/4,697) of the study population, which included patients from 9 countries. <i>ALKr</i> distribution for each country was: Mexico 7.6% (79/1,034), Colombia 4.1% (10/242), Argentina 6.0% (153/2,534), Costa Rica 9.5% (13/137), Panama 4.4% (5/114), Uruguay 5.4% (2/37), Chile 8.6% (16/185), Venezuela 8.9% (13/146), and Peru 10.8% (29/268). RT-PCR showed high positive (83.6%) and negative (99.7%) predictive values when compared to the gold standard FISH. In contrast, IHC only showed a high negative predictive value (94.6%). <b><i>Conclusions:</i></b> Although there is a clear country and continental variability in terms of <i>ALKr</i> frequency, this difference is not significant and the overall incidence of <i>ALKr</i> in Latin America does not differ from the rest of the world.