Signal peptide missense variant in cancer-brake gene CTLA4 and breast cancer outcomes

The cancer-brake gene CTLA4 has a vital function in suppressing the immune responses of activated T lymphocytes. Numerous reports explored the impact of various CTLA4 variants with the predisposition for malignancies but with unconvincing findings. Hence, this study is designed to assess the association of CTLA4 (c.49A > G, rs231775) variant with the outcome of breast carcinoma. A total of 272 participants (93 BC patients and 179 cancer-free healthy volunteers) were enrolled. Genomic DNA for all participants was genotyped for CTLA4 (c.49A > G) variant via TaqMan genotyping assay. Patients with A/G genotype conferred protection against developing BC under heterozygote comparison (OR = 0.56, 95%CI = 0.31-0.98) as well dominant model (OR = 0.55, 95%CI = 0.32-0.97). AG/GG genotypes were anchored with an increased risk of nodal infiltration (OR = 2.90, 95%CI = 1.03-8.17, P = 0.037), metastasis (OR = 4.46, 95%CI = 1.18-16.8, P = 0.019), advanced clinical stage (OR = 6.54, 95%CI = 2.06-20.75, P < 0.001), recurrence (OR = 5.2, 95%CI = 1.73-15.7, P = 0.001), and shorter survival (OR = 2.54, 95%CI = 1.08-5.99, P = 0.032). In addition, functional enrichment analysis revealed the key role of CTLA4 in cancer immunosurveillance. Our findings indicated that the CTLA4 c.49A > G variant might have prognostic as well diagnostic impact in breast cancer.