# The updated relationship between the cleft‑lip and palate transmembrane protein‑1‑like rs401681 and lung cancer risk: A systematic review and meta‑analysis

## TL;DR

This study finds that a genetic variant (rs401681) in the CLPTM1L gene is linked to a reduced risk of lung cancer, especially in Caucasians.

## Contribution

The study provides updated evidence on the association between CLPTM1L rs401681 and lung cancer risk through a comprehensive meta-analysis.

## Key findings

- The CLPTM1L rs401681 polymorphism is significantly associated with reduced lung cancer risk in Caucasians across multiple genetic comparisons.
- Ethnicity is a major source of heterogeneity in the association between rs401681 and lung cancer risk.
- Among Asians, the protective effect is observed only in the TT vs. CC genetic comparison.

## Abstract

Currently, the role of cleft-lip and palate transmembrane protein-1-like (CLPTM1L) rs401681 in various tumor types, particularly lung cancer, has garnered significant attention. However, the findings across studies have shown discrepancies. The aim of the present meta-analysis was to provide a more nuanced understanding of the involvement of CLPTM1L rs401681 in lung cancer development. Several electronic databases were systematically searched, including PubMed, Cochrane Library, Embase, Medline, Wanfang, Google Scholar and Chinese National Knowledge Infrastructure. Odds ratios (ORs) and 95% confidence intervals (CIs) were synthesized using random-effects models. Heterogeneity of included studies was assessed using the I2 statistic and Q test. Sensitivity analysis was conducted to evaluate the stability of overall estimates. Moreover, Egger's test was utilized to detect potential publication bias. The collective ORs indicated a significant association between the CLPTM1L rs401681 polymorphism and susceptibility to lung cancer across various genetic comparisons. These encompass allele T vs. allele C (OR=0.93, 95% CI=0.88-0.99, P<0.001), TT + CT vs. CC (OR=0.91, 95% CI=0.87-0.96, P<0.001), TT vs. CC + CT (OR=0.88, 95% CI=0.80-0.96, P<0.001), TT vs. CC (OR=0.84, 95% CI=0.75-0.94, P<0.001) and CT vs. CC (OR=0.84, 95% CI=0.75-0.94, P<0.001). Examination through statistical Q test and I2 statistic revealed pronounced heterogeneity across four genetic comparisons (allele T vs. allele C, TT + CT vs. CC, TT vs. CC and CT vs. CC). Ethnical distinctions emerged as the primary, if not exclusive, sources of the significant heterogeneity. Upon stratification by ethnicity, a notable reduction in heterogeneity was discernible within the Caucasian demographic. However, heterogeneity persisted within the Asian population. Furthermore, lung cancer risks were statistically significantly decreased for individuals possessing allele T through all genetic comparisons within Caucasians; whereas among Asians, significant reduction was observed solely in the TT vs. CC comparison. The present meta-analysis uncovers a significant association between the CLPTM1L rs401681 polymorphism and altered susceptibility to lung cancer.