Polymorphisms of DNA repair genes are risk factors for prostate cancer

Polymorphism of XRCC1 predicts overall survival of gastric cancer patients receiving oxaliplatin-based chemotherapy in Chinese population

Pharmacogenetic advances in cancer chemotherapy have the potential to predict clinical benefit to particular regimens. Platinum agents have shown to be effective in the treatment of gastric cancer. We assessed whether single nucleotide polymorphisms (SNPs) in xeroderma pigmentosum group D (XPD), X-ray repair cross complementing group 1 (XRCC1) and glutathione S-transferase P1 (GSTP1) predicted overall survival in gastric cancer patients receiving oxaliplatin-based chemotherapy in Chinese population. SNPs of XPD-751, XRCC1-399 and GSTP1-105 in 62 gastric cancer patients were evaluated using the TaqMan 5' nuclease assay. Genotypes were correlated to survival. The median overall survival time was 322 days (range: 56-2058 days). The median survival times for patients with Arg/Arg or Arg/Gln genotypes of XRCC1 gene were significantly longer than others (P=0.03). For 58 patients with ECOG PS (Eastern Cooperative Oncology Group performance status)<or=2, more obvious significance was demonstrated (P=0.002). Patients with XRCC1-399 Gln/Gln genotype demonstrated a significant worse survival. No significant association was found between SNPs of XPD-751, GSTP1-105 and survival (P=0.125, 0.475, respectively). XRCC1 genotyping might make tailor chemotherapy possible for gastric cancer patients treated with oxaliplatin-based chemotherapy.

Gene Expression and Polymorphisms of DNA Repair Enzymes: Cancer Susceptibility and Response to Chemotherapy

Platinum compounds play a central role in cancer chemotherapy. Although treatment is limited by side effects, they continue to have widespread application. One of the main aims of clinical or translational research in cancer is the search for genetic factors that could foresee treatment outcomes, in biologic activity and toxic effects. This genetic analysis might allow selection of patients who will have the greatest benefit from chemotherapy. Furthermore, a better knowledge of the underlying molecular profile of the host and the tumor will facilitate screening for lung cancer susceptibility and tailoring of chemotherapy in individual patients, choosing those most likely to respond, adjusting doses more precisely in order to reduce less adverse effects, and establishing safety profiles based on individual genetic analyses. Herein, we discuss current knowledge regarding gene expression and polymorphisms of DNA repair enzymes in regard to cancer susceptibility and response to chemotherapy.