In addition to predicting risk of cancer, genes can also make a difference in treating cancer
By Deborah Jeanne Sergeant
Many factors play into why cancer develops, both known and unknown.
For some people, family history plays a role, yet only 5% to 10% of cancers are caused by inherited gene mutations, according to the Am
erican Cancer Society. Other health factors, such as obesity, diet, exercise and stress management make a difference as do environmental influences, including radiation, certain chemicals, tobacco use and smog exposure.
The American Cancer Society recommends exploring genetic testing for people who have a strong family history of certain types of cancer, those already diagnosed with cancer (especially if it appears an inherited mutation could have caused it), and people whose family members have a known inherited gene mutation.
Laura K. Fisher echoed that recommendation. She is a certified genetic counselor and director of genetic counseling at Windsong, which offers radiology, genetic counseling, vein care and breast care in Williamsville.
“It’s based on their personal or family history,” Fisher said. “An individual who is diagnosed with a cancer at a young age like breast or colon at 45 or younger is a good candidate for genetic testing.”
She added that other examples include those with three or more relatives with the same type of cancer, Ashkenazi Jewish ancestry, or family history of a rare cancer, such as male breast cancer or ovarian cancer.
People with these risk factors should talk with their care provider or schedule a consultation with a certified genetic counselor. Most specialists do not require a referral.
A lack of a gene mutation does not mean cancer cannot occur.
“We often talk with women on knowing their history and knowing their genetics, but a family history doesn’t preclude you from having breast cancer,” said Andrea Moran, executive director of the Upstate New York Affiliate of Susan G. Komen Breast Cancer Foundation. “They may say, ‘No one ever had it in my family history’ or ‘It doesn’t show up in my genetic testing,’ but that doesn’t mean you should take your eye off regular screening, at home breast care and mammograms.”
Moran encourages people to “know your normal” when it comes to their own bodies.
Whether it is the breasts or other areas of the body, “if you see something abnormal, that should prompt a call to a provider,” Moran said.
For those who undergo genetic testing, it is important to understand how a mutated cancer risk gene, such as BRCA1, BRCA2 or Chek2 for breast cancer, can affect health in other ways.
“There are types that are linked to multiple types of cancer,” said physician Joyce Ohm, with Roswell Park Comprehensive Cancer Center. “If a patient has many family members with cancer, it may make sense to do additional genetic testing.”
Ohm encourages people with cancer gene mutations to remain vigilant about their health and to ask their providers about other screenings and preemptive measures they may need.
Most insurance companies cover genetic testing for people with enough risk factors. The testing can reveal if they carry genes that raise their lifetime risk of cancer or if wait-and-see is a reasonable approach.
While preemptive surgery is not easy, it virtually eliminates the risk of ever needing cancer treatments for that type of cancer. Patients are essentially consenting to surgery now to avoid the great likelihood of surgery plus chemotherapy or radiation later.
People with genetic predisposition to certain types of cancer must also determine how preemptive surgery would affect other areas of life. A young adult who had not yet had children may want to delay surgery that would affect fertility, for example, compared with someone who has already had a family.
Instead of paying for frequent rounds of imagery, insurance companies are usually more ready to pay for preemptive surgery and reconstruction for patients with high risk cancer gene mutations.
Ohm said that many more gene mutations have been identified than even several years ago. For people who have undergone genetic testing several years ago, “it’s worth talking with their physicians.”
In addition to predicting risk of cancer, genes can also make a difference in treating cancer. Diagnosed patients have treatment “based on their tumor type and that guides therapy,” Ohm said. “It will help guide prognosis and treatment choices and understand the severity and type of the cancer they had.”
Ohm added that years ago, all breast cancer was lumped into once category, but now physicians distinguish among different types, based in part by genetic testing.
Albert Rizzo, MD, chief medical officer with the American Lung Association, said that in the past five to 10 years, “there are at least 20 new drugs targeting mutations.”
The treatment is most effective if begun with an early diagnosis.
“It’s probably more relevant in lung cancer because that’s where the genetic markers have been identified,” Rizzo added. “It’s part of the discussion when you talk with an oncologist. One question is, ‘Will my treatment change if we do genetic testing?’ They may give good reasons as to why they don’t want to do genetic testing. It may depend on the stage of the cancer or comorbidity of the patient.”
Cancer at a Glance
• This year alone, breast cancer is estimated to be diagnosed in more than 252,000 women.
• Of those 252,000 women, an estimated 12,600 to 25,200 have a BRCA mutation.
• If you have a BRCA1 mutation, you have an estimated 72% chance of developing breast cancer by age 80. If you have a BRCA2 mutation, you have an estimated 69% chance of developing breast cancer by age 80.
• 100% of patients with ovarian cancer and pancreatic cancers should consider genetic testing.
• One in 10 breast cancers have hereditary causes
• One in six patients with prostate cancer have a germline variant (gene variation)
• One in five patients with pancreatic cancer have a germline variant.
Source: BeBRCAware.com and www.invitae.com.
Photo: Laura K. Fisher, right, talks to a patient at Windsong, which offers radiology, genetic counseling, vein care and breast care in Williamsville. Fisher is a certified genetic counselor and director of genetic counseling at Windsong.