Testicular cancer patients may be treated with bleomycin, a cytotoxic drug that is essential component of chemotherapy regimens for this cancer, officially known as disseminated testicular germ-cell cancer (TC). rs1050565 is a SNP in the BLMH gene. This gene encodes a protein that can inactivate bleomycin. Based on a study of 300 TC patients treated with bleomycin, a testicular cancer patient with a rs1050565(G;G) genotype has an odds ratio of 4.97 (CI: 2.17 - 11.39) for TC-related death compared to (A;G) or (A;A) genotypes. The rs1050565(G;G) genotype also shows a higher prevalence of early relapses.
Note that this gene affects bleomycin metabolism; the GG does not mean that a person is more likely to get testicular cancer.