XRCC4 polymorphisms have been linked to a risk of susceptibility for cancers such as bladder cancer, breast cancer, prostate cancer, hepatocellular carcinoma, lymphomas, and multiple myeloma. With respect to bladder cancer, for example, the link between XRCC4 and risk of cancer susceptibility was based on hospital-based case-control histological studies of gene variants of both XRCC4 and XRCC3 and their possible association with risk for urothelial bladder cancer. The linkage with risk for urothelial bladder cancer susceptibility was shown for XRCC4, but not for XRCC3   With regard to breast cancer, the linkage with "increased risk of breast cancer" was based on an examination of functional polymorphisms of the XRCC4 gene carried out in connection with a meta-analysis of five case-control studies .
Genetic variations in XRCC4 have been linked to increased risks for various cancers such as bladder cancer, breast cancer, prostate cancer, hepatocellular carcinoma, lymphomas, and multiple myeloma. Specifically, the association between XRCC4 and urothelial bladder cancer risk was observed through case-control studies that analyzed gene variants of both XRCC4 and XRCC3. The link to urothelial bladder cancer was confirmed for XRCC4 but not for XRCC3. For breast cancer, an "increased risk" connection was based on a study examining functional polymorphisms in the XRCC4 gene within a meta-analysis of five case-control studies.