Some 70 percent of women with early-stage breast cancer and an intermediate risk of cancer recurrence can safely skip chemotherapy after their tumors have been removed, US researchers said on Sunday.
“This is a major finding,” said Dr. Larry Norton, a breast cancer expert at Memorial Sloan Kettering Cancer Center in New York, who helped organize the government-funded study more than a decade ago.
“It means that maybe 100,000 women in the United States alone do not require chemotherapy,” Norton said.
The research, presented at the American Society of Clinical Oncology (ASCO) meeting in Chicago, studied how to treat women with early-stage breast cancer that responds to hormone therapy.
Women were deemed to have a medium level risk of the cancer coming back based on a 21-gene panel known as Oncotype DX from Genomic Health. The test predicts the likelihood of cancer recurrence within 10 years.
Those who score low on the test – from zero to 10…