Differences in the risk association of TERT-CLPTM1L rs4975616 (A>G) with lung cancer between Caucasian and Asian populations: A meta-analysis
Authors: Wu Xiaozheng , Li Wen , Chen Yunzhi 
Published: September 2024

Background
Although the G allele variant of TERT-CLPTM1L rs4975616 has been confirmed to be negatively associated to the risk of lung cancer (LC), some other studies haven’t found this negative association. The purpose of this study is to clarify the association of the rs4975616 with the risk of developing LC and the differences of this association among patients with different ethnicities (Caucasians and Asians), different subtypes of LC, and different smoking status.

Methods
Relevant literatures published before July 20, 2023 in PubMed, EMbase, Web of Science, MEDLINE databases were searched through the Internet. Statistical analysis of data was performed in Revman5.3, including drawing forest plots, funnel plots and so on. Sensitivity and publication bias were performed in Stata 14.0. The stability of the results was assessed using Test Sequence Analysis (TSA) software. Registration number: CRD42024568348.

Results
The G allele variant of rs4975616 was negatively associated with the risk of LC ([OR] = 0.86, 95%CI [0.84, 0.88]), and that this negative association was present in both Caucasians ([OR] = 0.85, 95%CI [0.83, 0.87]) and Asians ([OR] = 0.91, 95%CI [0.86, 0.95]), and the strength of the negative association was higher in Caucasians than in Asians (subgroup differences: P = 0.02, I2 = 80.3%). Across LC subtypes, rs4975616[G] was negatively associated with the risk of NSCLC (LUAD, LUSC) in both Caucasians and Asians (P<0.05) and the strength of the association with NSCLC (LUAD) was higher in Caucasians than in Asians (Subgroup differences: I2>50%). In Caucasians, rs4975616[G] was negatively associated with the risk of LC in both smokers and non-smokers (P<0.05), and the strength of the association did not differ between smokers and non-smokers (Subgroup differences: P = 0.18, I2 = 45.0%). In Asians, rs4975616[G] was mainly negatively associated with the risk of LC in smokers (P<0.05) but not in non-smokers ([OR] = 0.97, 95%CI [0.78, 1.20]). Comparisons between the two populations showed that the strength of this negative association was higher in Caucasian non-smokers than in Asian non-smokers (Subgroup differences: P = 0.04, I2 = 75.3%), whereas the strength of this negative association was the same for Caucasian smokers as for Asian smokers (Subgroup differences: P = 0.42, I2 = 0%). Among the different LC subtypes, rs4975616[G] was negatively associated with the risk of NSCLC (LUAD) incidence in both Asian smokers and Caucasian non-smokers (P<0.05), whereas it was not associated with the risk of NSCLC development in Asian non-smokers (P>0.05). Comparisons between the two populations showed that the strength of the association was higher in Caucasian non-smokers than in Asian non-smokers (Subgroup differences: I2>50%).

Conclusion
The G allele variant of rs4975616 is negatively associated with the risk of LC and NSCLC (LUAD, LUSC). Compared with Asians, Caucasians are more likely to have a higher risk of LC and NSCLC (LUAD) due to the rs4975616 variant. In Caucasians, smoking and other factors like non-smoking contribute to rs4975616 variations leading to LC, and other factors like non-smoking also induce rs4975616 variations leading to NSCLC (LUAD). In Asians, smoking is the major risk factor for the induction of rs4975616 variations leading to LC and NSCLC(LUAD).