Gender Impacts Colon Cancer Progression

USC study shows that sex-specific genomic profiling predicts clinical outcome in colorectal cancer treatment.

“This is the very first study showing that molecular markers may be sex specific,” said principal investigator Heinz-Josef Lenz, professor of medicine at the Keck School.Physiological differences between men and women may contribute to differential tumour development and progression in colon cancer patients, suggests a study led by University of Southern California researchers. “Taking gender into account when examining the genetic profile of patients may help those who will benefit from specific chemotherapy treatments,” said principal investigator Heinz-Josef Lenz, professor of medicine at the Keck School of Medicine of USC. Findings from the study were displayed June 4 at the annual meeting of the American Society of Clinical Oncology (ASCO) held at McCormick Place in Chicago. The study focused specifically on patients who had been treated with 5-Fluorouracil and oxaliplatin chemotherapy. Researchers were able to identify molecular markers predicting response time to tumour progression and overall survival. “When we stratified for men and women, different genes appear to be predictive for outcome,” Lenz said. “This is the very first study showing that molecular markers may be sex specific.” There has been increasing evidence that gender plays a significant role in the development and progression of colorectal cancer, Lenz explained. Colorectal cancer rates are higher among men, and previous studies have shown a protective effect of female hormones. Seventy-four female and 78 male patients participated in the study, which analysed 24 polymorphisms in 12 genes involved in cancer progression. Researchers tested for association of specific polymorphisms with overall survival (OS), time to tumour progression (TTP) and tumour response. Men carrying polymorphisms in the ER-beta and SCN1A genes had improved TTP, versus women carrying polymorphisms in the XPD and EGFR genes. Likewise, male patients carrying ER-beta and MTHFR polymorphisms had improved overall survival, while female patients carrying polymorphisms in SCN1A and PLA2 genes had improved OS. “These findings are critical since men and women are usually not divided when molecular research is being done,” Lenz explained. “Our results suggest for the first time that genomic profiling to predict clinical outcome of patients with metastatic colorectal cancer depends on gender.” Funding for this study come from the San Pedro Guild and Cornelius Pings Memorial Fund.(Source: American Society of Clinical Oncology (ASCO) : Meghan Lewit : University of Southern California : July 2007)