More than 1 million American women have been overtreated for cancer

Scientists say more than 1 million women in the US have undergone unnecessary cancer treatment in the past 30 years because X-rays detected benign tumors.

The results cast fresh doubt on the effectiveness of the cancer-screening tool, which is already controversial despite its aim to help detect tumors before they spread and become difficult to treat.

Illustration photo. (Source: venusbuzz.com)

To arrive at the more than 1 million figure, researchers compared the number of early- and late-detected breast cancers treated among women aged 40 and older between 1976 and 2008.

Their analysis found that since screenings became standard in the United States, the number of breast cancers detected early has doubled; in recent years, doctors have found tumors in 234 out of every 100,000 women who have had screenings. However, during the same period, the percentage of women diagnosed with late-stage breast cancer has dropped by only 8 percent, from 102 to 94 out of every 100,000.

“We suggest that breast cancer has been overdiagnosed, specifically tumors detected by screening that would never have led to serious symptoms, in 1.3 million American women over the past 30 years,” said Gilbert Welch of Dartmouth Medical School and Archie Bleyer of Oregon Health and Science University, in a study published in the New England Journal of Medicine. “In 2008, breast cancer was overdiagnosed in more than 70,000 women, accounting for 31 percent of all breast cancer diagnoses.”

The authors stress that these women are more likely to have undergone major medical interventions, including surgery, radiotherapy, hormone therapy and chemotherapy, which are typically used only when absolutely necessary.

They concluded that the dramatic reduction in breast cancer deaths could best be explained by improvements in treatment rather than early detection through screening.

The study adds to work published in recent years that has cast doubt on whether X-rays are a cancer prevention tool.

One study in Norway found that routine mammograms reduced the risk of dying from breast cancer by nearly 10%, but another study, comparing European countries that adopted the measure in the 1990s and those that used it more widely in the 2000s, concluded that the screening tool did not reduce deaths.

In 2009, a panel of independent experts commissioned by the U.S. government reviewed recommendations on when and how often women should get mammograms, saying most women should start getting them at age 50 rather than 40. But a separate paper published in the New England Journal of Medicine argued that despite this overdiagnosis, women should start getting them at age 40.

Despite advances, breast cancer remains the most common cancer in women and the leading cause of cancer death among women worldwide. Each year, 1.4 million cases of breast cancer are diagnosed worldwide./.

According to (Vietnam+) - VT