Smarter Than Cancer Podcast: Can we treat cancer across families?

While it is impossible to determine when, or whether, someone will develop cancer, understanding a person’s family history can play an important role in finding it sooner. 

“We all have a risk for cancer, unfortunately, but we know people who have a genetic risk just have an increased risk. But it’s not a guarantee,” explains Mollie Hutton, MS, CGC, a genetic counselor at Roswell Park Comprehensive Cancer Center. 

By undergoing genetic testing, doctors and patients alike can have a better understanding of a person’s risk for developing cancer by looking for mutations linked with a higher risk, such as BRCA1 and BRCA2 mutations associated with breast, ovarian and prostate cancer among families. 

Not all genes or mutations are associated with hereditary predispositions for developing cancer. “Of the 22,000 genes that are the instructions for our cells, only a very small subset, somewhere between 40 and 100, function to defend against cancer,” says Kenan Onel, MD, PhD, Chief of Clinical Genomics at Roswell Park. “The sequence for those 40 to 100 genes is analyzed computationally. What the laboratory is looking for is an off switch that turns off one of those genes that functions to defend against cancer. If you turn off a gene that functions to defend against cancer, that’s associated with an increased risk of cancer." 

Genetic testing is a process that involves collecting a sample of blood or saliva to look at a person’s genes and based on the information found by experts, determine whether someone should be more closely monitored for developing cancer. “If we identify somebody as having higher risks, often the first step we take to changing their medical care is about screening, so if something were to come up, we make sure it’s going to be caught at its earliest and most treatable stage,” Hutton says. 
 

Even this isn’t a slam-dunk tool for predicting if someone will develop cancer, Dr. Onel warns. If a family has a history of prostate cancer going back several generations, but they all test negative for any genetic mutation associated with prostate cancer, “that suggests there may be some sort of as-yet-unknown genetic predisposition that is carried by the cancer-affected family members. That’s something we like to do in the laboratory, which is try to discover novel or previously unknown genetic tumor predisposing conditions.” 

Under Dr. Onel’s guidance, Roswell Park is the first cancer center in the country to offer a medical home for individuals and families at higher risk for developing cancer based on their genetics, where patients and their relatives can provide DNA samples to better understand their cancer risk and have access to more frequent screening tests to detect cancer earlier. 

The goal is both scientific and to provide insight to those families. “If we can tell them what they’re up against, then we can devise a plan to help keep them safe. We can come up with hypotheses about what genes are predisposing and why. Then, if we have other family members for whom we also have tumor and normal cells, we can ask whether they too show the same pattern,” Dr. Onel says. “Armed with information from one family, we can look across the range of families with a condition and ask whether we are seeing something similar and, in that way, we can identify new predispositions,” a science he calls functional genomics. 

Not everyone who has a possible family risk of cancer is going to be interested in learning whether they possess the same genetic mutation, and that’s understandable; the goal of Roswell Park offering genetic testing to all patients is to amass information that could help uncover new mutations that could identify different links to further help demystify the causes of cancer, Hutton says.