In NEJM this week, researchers in Michigan, North Carolina, and Arizona identify germline mutations in HOXB13 that may increase a person's risk for prostate cancer. Family history has been shown to be a significant risk factor for prostate cancer, but its molecular basis has not yet been properly understood, the researchers write. In this study, the team screened more than 200 genes on chromosome 17q21-22 from germline DNA of 94 patients with familial prostate cancer. They found that probands from four families had a rare mutation, called G84E, in the HOXB13 gene, which plays an important role in prostate development. "All 18 men with prostate cancer and available DNA in these four families carried the mutation," the authors write. "The carrier rate of the mutation was increased by a factor of approximately 20 in 5,083 unrelated subjects of European descent who had prostate cancer, with the mutation found in 72 subjects (1.4 percent), as compared with 1 in 1,401 control subjects (0.1 percent)." The mutation was particularly common in men with early-onset familial prostate cancer, the researchers add, leading them to conclude that this gene variant is associated with a significantly increased risk of hereditary prostate cancer. "Although the variant accounts for a small fraction of all prostate cancers, this finding has implications for prostate-cancer risk assessment and may provide new mechanistic insights into this common cancer," the authors suggest.
Also in NEJM this week, an international team of researchers assesses the efficacy of pertuzumab plus trastuzumab plus docetaxel as a combination treatment for metastatic breast cancer. The researchers randomly assigned 808 patients with HER2-positive metastatic breast cancer to receive either pertuzumab plus trastuzumab plus docetaxel, or trastuzumab plus docetaxel and a placebo. The team found that median progression-free survival was 18.5 months in the pertuzumab group compared to 12.4 months in the control group. An interim analysis of overall survival showed a trend in favor of the pertuzumab group. "The combination of pertuzumab plus trastuzumab plus docetaxel, as compared with placebo plus trastuzumab plus docetaxel, when used as first-line treatment for HER2-positive metastatic breast cancer, significantly prolonged progression-free survival, with no increase in cardiac toxic effects," the team writes.