Everyone wants to find a cure for cancer. But what many don’t realize is that an important part of curing cancer is being able to diagnose the disease early.
Lung cancer, which can be treated through surgery, is one example of the importance of early detection. Currently only 16 percent of the more than 170,000 cases of lung cancer diagnosed each year are detected at a stage when surgeons can successfully remove the cancer.
Discovering lung cancer biomarkers — chemical clues that can point to the presence of cancer — could increase that number. Some of those answers may lie in genes.
Many genes protect cells from cancer, explained Gerd Pfeifer, Ph.D., professor and chair of the Division of Biology at City of Hope. But certain genes, including protective ones, can become silenced or inactive in cancer.
Scientists can detect many silenced genes through biochemical tests because the genes are modified through a process called methylation. Recently, Pfeifer and his fellow lab scientists focused on detecting these abnormally silenced genes in lung cancer cells. The techniques may eventually be used to diagnose lung cancer early.
“There is a population of high-risk, heavy smokers who could be screened both by advanced imaging techniques and molecular testing,” Pfeifer said. Molecular testing could be done without invasive procedures, possibly even by testing mucus coughed up from the lungs.
In a recent study published in the journal Proceedings of the National Academy of Sciences, Pfeifer’s group identified regions of a specific class of genes that were incorrectly modified in lung cancer cells.
Two genes, called HOXA7 and HOXA9, lit up as methylation “hot spots” in lung cancer, reported Pfeifer’s collaborator, Tibor Rauch, Ph.D. “HOXA9 was a very early target of DNA methylation in lung cancer. It could be a very promising marker candidate for diagnostic kits.”
HOX genes are part of normal embryonic development in organisms ranging from insects to humans. No one knows why they’re methylated in cancer, Pfeifer said, but because they’re so important to the earliest stages of a cell’s development, their silencing “supports the hypothesis that cancer arises from stem or progenitor cells.”
As promising as molecular detection methods may be, they’re no cause for complacency about cancer risk. Leading a healthy lifestyle and paying attention to clues from your body are still the best ways to reduce your cancer risk or catch developing cancer early. Among doctors’ recommendations:
Don’t use tobacco products
Stay physically active and eat a healthy diet
Avoid and treat obesity
Follow your doctor’s advice and get recommended health screenings regularly, whether they be Pap smears, colonoscopies, mammograms or other appropriate tests. Screening guidelines for men are available at www.ahrq.gov/ppip/healthymen.htm while women’s guidelines are online at www.ahrq.gov/ppip/healthywom.htm.