Annette Page, left, and her sister, Sharee, received a breast cancer diagnosis within about two weeks of one another.

SALT LAKE CITY — Every three weeks, two Utah sisters sit together in matching chairs and chat as their bodies are pumped full of chemotherapy drugs.

Sharee Page, 34, and Annette Page, 36, were diagnosed with breast cancer within about two weeks of each other, a coincidence that doctors say is extremely rare. But that coincidence has meant they can face the disease like they have nearly every other aspect of their lives — as a team.

“Wow, talk about a huge blessing,” said Annette Page, who lives five minutes from her sister in northern Utah. “Who gets to go through something so hard with their best friend, their sister?”

The “Page Sisters,” as some of their friends like to call them, found out soon after their diagnosis that they have the BRCA2 gene, a mutation that puts a woman at a much greater risk for breast and ovarian cancers. BRCA mutations, which stands for breast cancer susceptibility gene, are most commonly found in women of Ashkenazi Jewish descent, although some northern European populations also have a higher risk of inheriting one of the mutated genes.

Adam Cohen, a doctor at the University of Utah’s Huntsman Cancer Institute, said the gene can increase the risk of breast cancer tenfold. But Cohen said he has never seen two siblings diagnosed within weeks of one another.

“It’s not uncommon to have somebody with breast cancer and BRCA2 mutation and whose sibling develops breast cancer,” he said. “But doing it within two weeks is certainly very uncommon.”

In late March, after discovering a large lump in her left breast, Annette Page was diagnosed with Stage 3 breast cancer. The news prompted Sharee Page to get herself checked, and the same doctor soon diagnosed her with Stage 2 breast cancer.

“Had she not been diagnosed, I don’t think I would have caught mine for six months to a year,” Sharee Page said.

Every few weeks, the sisters go to their six-hour chemotherapy session. Afterward, they experience a myriad of matching side effects, including nausea, bloody noses, neuropathy and headaches.

Their bodies react to the medicine in a nearly synchronized fashion. Both are unable to eat food for almost two weeks. Exactly 10 days after treatment, they break out in a rash.

“It’s nice to know that someone knows exactly what you’re going through,” Sharee Page said.

The women, who are part of a devout Mormon family, have four other siblings. One of their sisters also recently tested positive for the BRCA2 gene. But she does not have cancer, so she plans to get a double-mastectomy.

Cohen said that course of preventive treatment is sometimes recommended for someone who has the mutation and is cancer free.