Breast and Ovarian Cancers: What's the Link, and Should You Worry?

Patient Expert
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Breast cancer is the most commonly diagnosed women's cancer (with the notable exception of skin cancer). A woman’s risk of being diagnosed with breast cancer at some point during her lifetime is one in eight.

Ovarian cancer is much less common. According to the American Cancer Society (ACS), a woman’s lifetime risk for ovarian cancer is just one in 75. But of the two cancers, ovarian is much more deadly.

The ACS estimates that about 22,440 women will be diagnosed with ovarian cancer this year — and 14,080 will die of it, a mortality rate of 63 percent. Contrast that with breast cancer’s mortality rate of just 16 percent, and it’s clear why it’s important to assess your own ovarian cancer risk.

While there’s a great disparity between outcomes, these two cancers are inextricably linked, at least for a portion of the population.

What’s the specific link between breast and ovarian cancer?

In a word: genes. The BRCA1 and BRCA2 genes have been identified as key determinants in whether or not a woman will be diagnosed with breast or ovarian cancer. Both of these genes help suppress tumors; when they become mutated, often by a series of small injuries, they lose their ability to work against tumors — and your cancer risk goes up, usually precipitously.

While BRCA gene mutations can happen randomly, they can also be passed along from generation to generation. A person whose mother or father carries the mutated genes has a 50 percent risk of carrying them his- or herself.

If you haven’t had either cancer and don’t have a serious family history of either disease, then there’s no need for you to worry. But if you’re at increased risk for either of these two cancers due to family history or an identified genetic mutation, you may have a condition called Hereditary Breast and Ovarian Cancer (HBOC), which affects about 1 percent of the general population.

According to the National Cancer Institute, being diagnosed with HBOC can raise your risk of ovarian cancer to as high as 39 percent, while breast cancer risk can reach 65 percent.

Can you determine if you’re in this small but dangerous risk group?

Yes. Genetic testing is commonly used to identify men or women with HBOC. Covered by most insurance companies under the Affordable Care Act, genetic testing is painless and yields results in about a month.

How do you know if you should undergo genetic testing?

Speak with your doctor. S/he’ll help you look at your family history to see if either breast or ovarian cancer is more than a random occurrence, either on your mother’s or father’s side. Your doctor will have a checklist of questions to ask, ranging from relatives’ ethnicity to the number, type, age at diagnosis, and outcome of cancer cases on both sides of your family. Our article on BRCA genetic testing will help you prepare.

If you and your doctor decide genetic testing is warranted, don’t put it off. It’s scary to think that you may be a “walking time bomb,” with cancer in your future a distinct possibility. But knowing you’re at increased risk for breast or ovarian cancer can help you make informed decisions about possible preventive treatment: e.g., removal of your breasts or ovaries, both of which reduce the risk of cancer significantly.

Bottom line

For the vast majority of us, both breast and ovarian cancer are random occurrences, no more predictable than a car accident or a tumble down the stairs. But there’s a genetic link between breast cancer and ovarian cancer for a very small percentage of the population — and knowing whether or not you’re in that small percentage could very well save your life.

See more helpful articles:

Family History Bigger Risk Than Lifestyle for Some Cancers

Introduction to Ovarian Cancer

How Family History Contributes to Breast Cancer Risk

Daily Aspirin Could Lower Ovarian Cancer Risk

Sources:

BRCA1 & BRCA2: Cancer Risk & Genetic Testing. (2015, April 1). Retrieved August 03, 2017, from https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet#q2.

Ovarian, Fallopian Tube, and Primary Peritoneal Cancer. (n.d.). Retrieved August 03, 2017, from https://www.cancer.gov/types/ovarian.

What Are the Risk Factors for Ovarian Cancer. (2016, February 4). Retrieved August 03, 2017, from https://www.cancer.org/cancer/ovarian-cancer/causes-risks-prevention/risk-factors.html.

Hereditary Breast and Ovarian Cancer. (2017, July 1). Retrieved August 03, 2017, from http://www.cancer.net/cancer-types/hereditary-breast-and-ovarian-cancer.