My Sister Has Breast Cancer: What Does That Mean for Me?

When Emily Adeyanju's older sister developed a cyst on her breast, it was originally diagnosed as benign. But within the cyst, a malignancy was growing, undetected. Once Adeyanju, a Manhattan writer and editor, learned her sister did have breast cancer, she was surprised as well as horrified. There wasn't any previous family history, so she'd thought chances of getting it were remote.

To Adeyanju, the focus was clear -- to get her sister well, if possible. "I really wasn't thinking about my own risk and my own health," she says. But the fact is, when a first-degree relative -- a mother, sister or daughter -- has breast cancer, there could be health implications for you.

Family History for Cancer

It's far more common for breast cancer to be sporadic -- with little or no family history -- than gene based, says Hannah Linden, a medical oncologist at the Seattle Cancer Care Alliance and an associate professor in oncology at the University of Washington. Her group takes care of cancer patients and also provides counseling for people at higher risk.

About 5 to 10 percent of breast cancer cases are hereditary -- arising from gene mutations, or defects, inherited from parents -- either from the mother's or father's side. Mutations in the BRCA1 and BRCA2 genes are most often involved. If a patient develops breast cancer, Linden says the ideal is for her to undergo genetic testing through a blood test and share the results with family members. The Center has an on-site service where genetic counselors talk to patients and family members about cancer risk assessment, and the pros and cons of genetic testing and being aware of your results.

If you're concerned about cancer risk, you also want to learn about your family's overall cancer history. Some types of cancer share genetic links. When Linden listens to a patient describe family history, ovarian and colon cancer cases get her attention along with breast cancer, as well as cancers that appear at younger ages. In previous eras, people were reluctant to talk about cancer, Linden notes. For instance, an aunt might have had a lumpectomy, but you don't know whether there was a cancerous or benign process at work. Or ovarian cancer might have been referred to as "stomach cancer."

Even today, some people don't readily bring up the topic, "but they are happy to talk about it when you inquire," Linden says. By asking a few questions at your next family gathering, you could learn a lot about your extended family's history. The American Society of Clinical Oncology has more about hereditary breast and ovarian cancer.

Read: [When Cancer Is in Your Genes]

A Sister's Caregiver

Adeyanju's immediate concern was helping her older sister: "I never would have let her go through anything like this alone." But she didn't know what to do, what to say to her 10-year-old nephew or how to support her mother, who was "just so very sad." She revealed the situation to her boss, who pointed her to the nonprofit group SHARE -- Self-Help for Women with Breast or Ovarian Cancer. The SHARE website included a list of ways caregivers can help, and Adeyanju learned she could do something that "seemed insignificant" yet helped a lot.

Her sister, who was working as a consultant at the time, didn't have insurance and appeared overwhelmed by appointments and arrangements that had to be made, and without any privacy in her open work cubicle to do so. "I said, 'I can make those calls,'" says Adeyanju, who recalls her sister saying, "Would you do that for me?" and her look of relief.

By working their phones and contacts, she and another sister arranged state-based emergency Medicaid coverage and connected their sister with an oncologist and treatment at the Memorial Sloan Kettering Cancer Center. Adeyanju accompanied her sister to appointments, initially asking questions until her sister was ready to ask for herself.

Adeyanju's sister went through radiation therapy, two chemotherapy regimens and surgery. Radiation side effects included infections and mouth sores. At one point, Adeyanju's sister told her, "This is too aggressive -- I feel so unlike myself. I can't eat, the mouth sores are terrible -- I just can't do this." Adeyanju did things like puréeing vegetables to help her sister get food down. And she encouraged her sister through the worst of chemo.

Through it all, Adeyanju attended a monthly SHARE caregiver circle, to learn how to support and empower her sister. By doing so, she says, "I also found out I needed to get my sleep; I needed to check on my own health; I needed to slow down sometimes and let another family member step in."

Read: [12 Questions to Ask When You're Diagnosed With Ovarian Cancer]

Self-Care and Screening

Adeyanju's gynecologist said they needed to look at her risk and advised a mammogram, although she was under 40, the standard age to begin screening. "Emily, you just told me your sister has stage 3 breast cancer," she recalls him saying. "You're getting your mammogram now." If her sister tested positive for the BRCA gene mutation, they would discuss her genetic risk and what to do next. Fortunately, Adeyanju's sister did not have a BRCA mutation.

However, Linden says, if you have a sister with breast cancer who is BRCA-positive, then you should get tested. But, she adds, "you need a balanced discussion with somebody who can walk you through it, and usually that person is a certified medical genetics counselor."

Insurance often pays for counseling, Linden says, but not always for the testing. "Usually you can get it covered if there's truly an indication," she says. "Fear is not an indication."

When healthy people are found to have a BRCA gene mutation, "that's a really tough conversation," Linden says. "You don't want people to feel they're fated. These are just probabilities. It's not a guarantee. There are people in families with the deleterious mutation, and [they] don't get cancer."

Men can get lost in the breast cancer conversation, because the condition is so much more rare for them. But it happens. "If you have a lump, you need to do something about it," Linden says. "And if you're obese; then you have male breasts, then you've got a higher risk." She says it's "very reasonable" for a brother of a woman with a gene mutation to get tested.

Read: [How to Cope With a Positive Genetic Test Result]drugs to reduce breast cancer riskthese medications

If you're found to be at higher risk, you may want to discuss with your doctor -- the American Cancer Society lists . Your doctor may recommend stepped-up screening, which can include more frequent mammograms, starting yearly mammograms at a younger age or adding on MRI scans or breast ultrasounds.

Prophylactic surgery -- preventive removal of the breasts or ovaries -- is a highly personal choice made by some healthy women with BRCA gene mutations, who have carefully weighed the risks and benefits with cancer experts. All women can reduce their modifiable risks for breast cancer by maintaining a healthy weight, being physically active and avoiding hormonal replacement therapy for menopause.

About 21 months after her breast cancer diagnosis, Adeyanju's sister is "doing OK," she says. "We've come a long way. It's been a long journey, a challenging journey. But I think we are a lot stronger as a family now, and we really hope and pray that this doesn't ever recur."

Read: [Diet Changes That Might Cut Breast Cancer Risk]

Lisa Esposito is a Patient Advice reporter at U.S. News. You can follow her on Twitter, connect with her on LinkedIn or email her at lesposito@usnews.com.