Dr. Laura J. Esserman, a breast cancer surgeon at the University of California, San Francisco, has dedicated much of her professional life trying to get medical establishments to think differently about breast cancer. She is one of the most vocal proponents of the idea that breast cancer screening brings with it overdiagnosis and overtreatment.

The study published in the journal JAMA Oncology was analysis of 20 years of patient data, which made the approach to treating a condition known as ductal carcinoma in situ (DCIS), for which the current practice includes only surgery.

Dr. Esserman is one in a few surgeons in the US who want to put women with DCIS on active surveillance instead of performing biopsies, lumpectomies or mastectomies.

She and other critics point the potential side effects and risks of sometimes disfiguring treatments for premalignant conditions that are unlikely to develop into life-threatening cancers.

Dr. Esserman has also challenged the conventional perception surrounding screening, arguing that while mortality from breast cancer has decreased over the past three decades, the approach to screening has to be changed.

Most lethal breast cancers appear between screens, while mammograms are finding more slow-growing cancers with a very low chance of metastasis, she said. The screening has revealed a reservoir of DCIS, also known as Stage 0, which now accounts for 20%to 25% of all breast cancer diagnoses.

Most patients will not be benefited from early detection of such lesions that she has recommended to the National Cancer Institute that for many DCIS lesions.

Breast cancer screening is the medical screening of asymptomatic, apparently healthy women for breast cancer in an attempt to achieve an earlier diagnosis. The assumption is that early detection will improve outcomes. A number of screening tests have been employed, including clinical and self breast exams, mammography, genetic screening, ultrasound, and magnetic resonance imaging.