What Cancers Can Genetic Counseling Predict?

Imagine a family grappling with a history of cancer. It happens. According to the National Cancer Institute, approximately 10 percent of all cancers may be caused by inherited genetic changes. Cancer can't pass down from parents to a child, but a genetic change that increases your risk of cancer can be inherited. That's why sometimes it might seem like cancer runs in families.

"Ovarian cancer is one cancer most linked to a genetic cause," said Tina Ayeni, MD, a gynecologic oncologist with Franciscan Physician Network Gynecologic Oncology Specialists Indianapolis. "About 25 percent of ovarian cancers occur because of mutated DNA, which you have no control over."

But it's also important to know that if you inherit a cancer-related genetic change, it doesn't mean you will get cancer. It only means you have an increased risk of developing cancer.

Is Genetic Testing For Cancer Worth It?

Genetic testing for cancer is a specialized service that can help you and your family understand the role genetics plays in your health. It's the first step in genetic testing. By analyzing your genetic information, counselors can identify genetic mutations or variations that may increase your risk for developing certain diseases, including cancer.

"For ovarian and fallopian tube cancer, if we know you have a genetic mutation, we can work to prevent the development of those cancers even before you've been affected," said Dr. Ayeni.

Getting genetic testing for cancer is a personal decision, and it's important to talk with a genetic counselor, your family and your healthcare provider before you decide to move forward with testing. Once you take the next step, you and your physician can review the results and, if needed, develop a plan to help prevent cancer from occurring.

What Cancers Can Be Detected Through Genetic Testing?

Researchers link several mutated genes to specific types of cancer, including stomach (gastric) and familial medullary thyroid cancer. Other, more common cancers also have genetic markers oncologists can identify with genetic testing.

Breast Cancer

Breast cancer is one of the most common cancers nationwide.

"Genetic mutations are important in the treatment and the prevention of breast cancer," said Erika Rager, MD, a general surgeon with Franciscan Physician Network Breast & Melanoma Specialists. "Some of the genes associated with breast cancer are the same as those associated with ovarian cancer."

For example, genetic testing can assess the risk for developing breast cancer by examining the BRCA1 and BRCA2 genes.

Ovarian Cancer

Ovarian cancer is often called the "silent killer" due to its subtle symptoms and difficulty in early detection. However, genetic testing can help identify inherited gene mutations, such as the BRCA1 and BRCA2 genes, that significantly increase the risk for developing this cancer.

Colorectal Cancer

Colorectal cancer is the third most common cancer in the United States, but early detection can improve treatment outcomes. Genetic testing can identify gene mutations associated with hereditary colorectal cancer syndromes, such as Lynch syndrome or familial adenomatous polyposis (FAP).

"Those with the Lynch syndrome gene can have nearly an 80 percent chance of developing colorectal cancer in their lifetime," said Meghana Raghavendra, MD, a hematologist oncologist with Franciscan Physician Network Oncology & Hematology Specialists Indianapolis. We recommend frequent colonoscopies to catch it early."

Prostate Cancer

Prostate cancer is the most common cancer among men. Genetic counseling can identify inherited genetic changes, such as mutations in the BRCA1 and BRCA2 genes, which can increase the risk for developing prostate cancer.

Melanoma (Skin Cancer)

Genetic counseling can also play an important role in predicting the risk of melanoma, the deadliest form of skin cancer. By analyzing specific gene mutations, such as CDKN2A, physicians can identify people with an increased predisposition (tendency) to melanoma.

Pancreatic Cancer

Some of the genes associated with breast cancer, such as BRCA2, are also associated with other cancers like prostate cancer, pancreatic cancer or melanoma, said Dr. Rager. Researchers have also identified many gene mutations that can increase pancreatic cancer risk.

What Is Hereditary Cancer Syndrome?

Hereditary cancer syndrome, also called family cancer syndrome, is a rare disorder that causes a higher-than-average risk for developing a specific type of cancer. These account for about 5 percent of all cancers.

For instance, "the FAP gene is responsible for increasing the risk for developing colorectal cancers and, in some instances, gastric cancer," said Dr. Raghavendra.

It is important to know that not all cancers that seem to "run in families" are caused by hereditary cancer syndrome and gene mutations. Certain other factors can contribute to more than one family member developing cancer. These can include:

• Environmental factors such as chemical exposure and air pollution
• Shared habits such as smoking
• Shared medical conditions
• Common exposures, such as lead and asbestos

These can all contribute to family members developing the same type of cancer.