Woman, 27, is diagnosed with breast cancer just 2 weeks before her sister, 32, receives the same diagnosis

When Katie Cooper woke one day in September, she felt a ping-pong-ball-sized lump on the right side of her chest.

“It felt hard and literally it sounds made up it that (it appeared) overnight,” Cooper, 27, of Charlotte, North Carolina tells TODAY.com. “I contacted my doctor … and was like, ‘Hey, so I’m kind of concerned about this.’” After exams, tests and a biopsy, Katie Cooper was diagnosed with triple-negative breast cancer. She and her sister Lyndsay Cooper, 32, both carry a BRCA1 mutation, a genetic change that increases one’s risk for breast and ovarian cancer.

This means they undergo surveillance, including breast MRIs, at a much younger age than most women. Two weeks after Katie Cooper was diagnosed with breast cancer, her older sister, Lyndsay Cooper, 32, learned she also had triple-negative breast cancer.

“By the time I had checked and found the lump in September, it was like 3 cm, which is pretty big, and felt rock hard, like really solid. It feels different than anything you’ve ever felt before,” Lyndsay Cooper of New York City tells TODAY.com. “I was like, ‘I’ll get this checked out. Get a biopsy.’ But I was like, ‘There’s no way that my sister and I both have breast cancer at the same time.’”

Home DNA kits lead to genetic finding

When Lyndsay Cooper was 25, she took a 23andMe test and learned she had a BRCA1 mutation. To be sure, she met with a genetic counselor for “legitimate” testing and discovered she indeed had it.

“I was so young that the doctors were like, ‘You don’t need a mammogram yet,” Lyndsay Cooper explains. “But I was getting the MRIs, checking on it.”

When Katie Cooper turned 25, she underwent genetic testing and learned she, too, had a BRCA mutation and began undergoing breast MRIs.

“That’s what made us a lot more aware of checking for lumps and going to see the doctors more regularly than the average person would,” Lyndsay Cooper says.

While Lyndsay Cooper once found a lump and needed a biopsy, it was benign. Then this fall, Katie Cooper found her lump and in some ways it felt surprising because her regular exam did not detect any breast changes. But when she came in for the exam in the fall, the nurse practitioner noticed a difference.

“The appointment was with the nurse practitioner who had seen me three months prior, and she was like, ‘This definitely was not there three months ago,’” Katie Cooper recalls. “She said, ‘I’m not overly concerned but we’re going to go ahead and we’re going to get your scan moved up.’”

In addition to undergoing an MRI, Katie Cooper also had a mammogram and ultrasound, which led to a biopsy.

“I could tell that (the ultrasound technician) was very concerned. Her demeanor changed,” Katie Cooper says. “She wasn’t really saying a lot, but it was more the lack of what she was saying that concerned me.”

Two “stressful” weeks passed as Katie Cooper awaited her test results.

“They confirmed that yes, it was cancer,” she says.

While Lyndsay Cooper had also undergone her regular exam which also did not detect changes to her breasts, she decided to do a self-breast exam because of her sister’s diagnosis and found a large, hard lump in her left breast.

“This type of cancer grows really fast,” Lyndsay Cooper says.

Two weeks after her sister’s diagnosis, Lyndsay Cooper learned she also had triple-negative breast cancer.

“It’s been a weird bonding experience of like texting each other and being like, ‘Hey this is what my doctor said,’” Lyndsay Cooper says. “It’s been really interesting.”

Both sisters have Stage 2 triple-negative breast cancer, which appears to be similar.

“Our masses are about the same size,” Lyndsay Cooper says.

They’re receiving chemotherapy with immunotherapy, which they’ll finish within two days of each other near the end of March. After about a month-long break from chemotherapy, they’ll both undergo bilateral mastectomies. They had planned on undergoing them as a preventative measure, which is often undertaken by people with BRCA mutations. Now it’s part of their treatment.

“Doctors strongly advise getting a mastectomy so that the cancer doesn’t return and it’s still not a 100% chance,” Lyndsay Cooper says. “It’s really so much better to go ahead and do that than to wait and see if it comes back.”

Both have grappled with side effects from treatment, including hair loss, nausea and exhaustion. Still, going through cancer treatment together makes it easier at times.

“Having her to just talk through things (has helped),” Katie Cooper says.

Triple-negative breast cancer

Triple-negative breast cancer acts aggressively, grows quickly, spreads further and is more likely to return, the American Cancer Society says. It often occurs in women younger than 40, Black women or those who have a BRCA1 mutation. Triple-negative means the cancer does not have estrogen or progesterone receptors and lacks or has very little of the HER2 protein, the organization notes. This cancer has fewer therapies than other breast cancers, too.

“The treatment of choice is chemotherapy,” Dr. Amy Tiersten, a professor in the division of hematology and medical oncology at the Icahn School of Medicine at Mount Sinai previously told TODAY.com. She doesn’t treat either sister. “It’s a type of breast cancer that is very responsive to chemotherapy.”

Patients also often undergo a mastectomy or a lumpectomy, the American Cancer Society says. In some cases, patients might also need radiation.

Like most cancers, early detection is key, and knowing the signs of breast cancer remains helpful. According to the American Cancer Society, symptoms include:

• Swollen breast or partial swelling

• Dimpling of the breast skin that can look like an orange peel

• Pain in the breast or nipple

• Changes to the breast skin such as redness, dryness, flakiness or thicker skin

• Discharge from the nipples

• Enlarged lymph nodes in the armpits or under the collarbones

‘If we help one person’

The Cooper sisters are donor-conceived, which is what, in part, prompted Lyndsay Cooper to do a home DNA test. They learned that the sperm donor carried the mutation, which was passed onto them.

“My sister and I have the same birth mother and the same sperm donor. So, we’re 100% biologically related,” Lyndsay Cooper says. “When all the DNA testing websites came out, we were very curious to see what we could find out.”

They also learned that they’re 50% Ashkenazi Jewish, a group at an increased rate of having a BRCA mutation, according to the Dana Farber Cancer Institute.

As a creative director at an ad agency, Lyndsay Cooper wanted to continue refining her social media skills and also thought that sharing their story on TikTok could help raise awareness of breast cancer.

“If we help one person do a self-exam and find something or help one person going through the same thing that is my big goal,” Katie Cooper says. “Lyndsay wants to spread some awareness.”

They’ve been surprised by the people who have responded, including some young people currently grappling with breast cancer and also some who had breast cancer earlier in their lives but are doing well now.

“I’ve definitely been getting a ton of comments,” Lyndsay Cooper says. “So many older women saying that they beat triple-negative cancer 10, 15 years ago and I feel so grateful that I’m going through it now with all the improvements that they’ve made in treatment.”

The sisters let some of their friends feel their lumps before treatment so they’d know what it felt like compared to other breast changes.

“It was very hard,” Katie Cooper says. “We’re told as women to do your breast exams but how do we know what we’re looking for? How do we know what we’re feeling for? Especially a lot of young women have lumpy breasts and dense breast tissue.”

Katie Cooper adds she’s glad there’s less of a stigma surrounding talking about breast cancer but hopes young women continue sharing their experiences.

“As women, we can lean on each other,” she says. “If I can support people going through this too then my goodness I absolutely want to.”

This article was originally published on TODAY.com