A hospital in Tokyo said Monday that it stands ready to conduct preventive mastectomies and that several women have undergone the operation there in the past after developing cancer in one breast.

St. Luke’s International Hospital said its ethics committee approved preventive mastectomy procedures in July 2011, allowing women who tested positive in genetic screening for breast cancer after finding the disease in one breast to opt for removal of the other.

The hospital made the announcement after American actress Angelina Jolie, 37, said last week that she decided to have a double mastectomy to reduce her chances of getting breast cancer after a faulty gene was found.

Another institution, the Cancer Institute Hospital of Japanese Foundation for Cancer Research, also plans to ask its ethics committee for permission later this month to offer preventive mastectomies.

Those found to carry mutated BRCA1 or BRCA2 genes are highly susceptible to breast cancer and can undergo such surgery at the two hospitals.

At St. Luke’s, none of the women had undergone mastectomies before developing the disease in one breast.

At the Cancer Institute Hospital, breast cancer screenings, including mammography examinations, are being conducted more frequently than before, but no one has requested a preventive mastectomy yet.

If either BRCA1 or BRCA2 mutates, the carrier has a 33 to 50 percent risk of developing breast cancer by the age of 50, and a 56 to 87 percent chance by the age of 70, research shows.

In Japan, 65,000 women, or one in every 15, developed breast cancer for the first time in 2008. Overseas data indicate that 5 to 10 percent of all patients inherit the disease.

In Japan, genetic screening for breast cancer costs around ¥200,000 to ¥230,000, and a mastectomy can cost from ¥700,000 to ¥1 million. Neither are covered by public health insurance.

The Health, Labor and Welfare Ministry said the public insurance system basically doesn’t cover preventive medicine and that it is difficult to make the insurance available only to potential breast cancer patients.

More than 80 hospitals in Japan conduct genetic screening for breast cancer, and about 1,600 women have done so since it was introduced in 2008.

Akihiro Yanagisawa, a senior member of CancerNet Japan, a group supporting cancer patients, said preventive mastectomies “can provide an option to women who are worried about breast cancer,” but said he was concerned about the financial cost to those who just want the screening.

Mika Masuda, a journalist specializing in medical issues who survived breast cancer, says that mental health care should be offered to people found to have a high risk of developing the disease.

“I believe many women cannot immediately accept undergoing a mastectomy after testing positive (in screening),” she said.