After adjusting for age, sex, histology, stage, ECOG performance status, smoking status, and radiation therapy in the Cox model, BRCA1 rs1799966 TC+CC genotypes were associated with a lower risk of death in patients with squamous cell carcinoma (HR = 0.324, 95% CI = 0.137−0.765, p = 0.010), patients ever smoked (HR = 0.406, 95% CI = 0.221−0.743, p = 0.004), or those with ECOG performance status of 1 (HR = 0.563, 95% CI = 0.353−0.898, p = 0.016). Here, BRCA1 is linked to squamous cell carcinoma.