What are cancer previvors?

Cancer carries a heavy emotional toll, no matter if you’re newly diagnosed or a long-term cancer survivor, or it’s your loved one who is navigating the disease. Among those who’ve never had the disease, there’s a group for whom cancer may also be top of mind. They’re previvors—people who are at higher risk of cancer. They may have a proven inherited mutation linked to a cancer syndrome, a family history of cancer that puts them at high risk or another predisposing factor.

Genetic predispositions run through some families. While it’s possible that a relative who has the mutation may never develop cancer, that may not allay the family’s fears regarding increased risk.

Some previvors may not know about the increased risk because their hereditary link to cancer has never been uncovered. Many previvors, even if a genetic connection hasn’t been verified, may suspect a connection because of a family history of specific forms of cancer.

DNA mutations

Our DNA generally works to keep us cancer-free. It’s when DNA mutates that we become susceptible to cancer. Most of the cancerous mutations that come about during a person’s life are triggered by a variety of risk factors, including smoking, excessive alcohol consumption, obesity, poor diet, or overexposure to the sun and other ultraviolet light.

Some mutations that are baked into our DNA from conception—passed down from our parents—may reduce our protections from certain types of cancer. Hereditary cancers make up about 5 percent to 10 percent of all cancer cases.

Genetic testing is needed to confirm or rule out a hereditary risk factor for cancer. A family history of cancer doesn’t always mean there’s an inherited gene mutation behind it. The family history may instead be related to an environment you’ve shared (whether it’s being smokers, getting sun exposure or living in an area with high radon levels or chemical exposure).

Is genetic testing right for me?

It’s important to understand that most people don’t need genetic testing. If your doctor thinks testing may be warranted, it’s recommended you meet with a genetic counselor first. The genetic counselor may perform a risk assessment and explain the testing procedures. Genetic counseling may also help you understand and cope with the results. Remember, testing can’t tell you whether you’ll develop cancer, only if you’re at increased risk.

The American Cancer Society lists a number of reasons that may lead someone to consider genetic testing. Those reasons include having:

• A close relative with cancer (mother, father, sister, brother, son or daughter)
• Several members on one side of your family (father or mother’s side) with the same type of cancer, or with cancers that may be linked to a single gene mutation 
• A family member with more than one type of cancer, with a rare cancer, or who developed cancer at a younger age than typical for that particular type
• An ethnic background (such as Ashkenazi Jewish ancestry) with a known hereditary link to a cancer syndrome, or a close relative with a cancer that’s connected to a hereditary cancer syndrome
• A physical condition linked to an inherited gene mutation

If there’s a reason to suspect a cancer syndrome runs in your family, the best person to be tested first may be the relative who has or has had the cancer—to determine whether he or she has an inherited variant for that type of cancer.

Inherited cancer syndromes

More than 50 hereditary cancer syndromes have been identified, including:

• BRCA1 and BRCA 2 hereditary breast and ovarian cancer syndrome (HBOC) 
• Diaphyseal medullary stenosis with malignant fibrous histiocytoma
• Duodenal carcinoid syndrome 
• Endolymphatic sac tumor
• Familial adenomatous polyposis (FAP)
• Familial isolated pituitary adenoma
• Gardner syndrome
• Hereditary diffuse gastric cancer
• Hirschsprung disease ganglioneuroblastoma
• Langerhans cell histiocytosis
• Li-Fraumeni syndrome
• Lynch syndrome
• Multiple endocrine neoplasia (type 1, type 2A and type 2B)
• MYH-associated polyposis
• Oslam syndrome
• Paraneoplastic neurologic disorders
• Perlman syndrome
• Stewart Treves syndrome
• Von Hippel-Lindau disease
• WAGR syndrome

An inherited mutation may be associated with more than one type of cancer. A BRCA gene mutation, for instance, puts women at higher risk of breast cancer and ovarian cancer, and it also increases the risk that a man may get breast, prostate or pancreatic cancer.

People with Lynch syndrome are at higher risk for colorectal cancer, stomach cancer, endometrial cancer, ovarian cancer and, to a lesser extent, other cancers as well. It may not be just a single gene mutation that puts someone at greater risk of cancer. It may be a combination of inherited variations on a number of different genes.

Genetic testing

Genetic testing is available for many types of cancer, including:

• Breast cancer
• Ovarian cancer
• Colon cancer
• Thyroid cancer
• Prostate cancer
• Pancreatic cancer
• Melanoma
• Sarcoma
• Kidney cancer
• Stomach cancer

Navigating previvorship

Support groups may help previvors deal with their emotions, such as certain fears or perhaps angst or guilt that a loved one may also have the genetic mutation. One group providing such support is FORCE (Facing Our Risk of Cancer Empowered).

Cancer previvors also may be proactive in protecting themselves as best as possible. Options may include:

• Monitoring
• Medications
• Elective surgery

Questions to ask your care team

If you’re a cancer previvor or think you may be one, here are some questions you may want to go over with your care team:

• When’s the right time to begin cancer screenings, such as colonoscopies for colorectal cancer previvors or mammograms for breast cancer previvors? How frequently should they be performed compared with standard screening recommendations for people without a hereditary mutation?
• How should a newly diagnosed previvor handle telling family members of their possible risk, especially if it involves a person who may prefer not knowing or if it may produce fears of having passed the gene onto a child?
• How expensive are the genetic tests, and does my insurance company cover such predictive testing?
• Are many additional tests needed after a faulty gene is detected?
• If the hereditary mutation is connected to a gynecologic cancer, how may that affect a woman’s fertility?
• Are there support groups available if I decide to undergo a double mastectomy and have breast reconstruction surgery?