Breast Cancer Screening May Reduce More Than Mortality Rates

Research presented at the 2017 San Antonio Breast Cancer Symposium found that breast cancer screening was associated with a reduction in a number of surgical and treatment procedures associated with breast cancer treatment.

“The value of population-based mammographic screening has been questioned by those who believe that the reduction in mortality from earlier diagnosis is outweighed by harms including over-diagnosis and overtreatment,” Dorothy Machalek, PhD, MPH, cancer epidemiologist at the Royal Women’s Hospital, in Melbourne, Australia, and colleagues wrote. “Much of these commentaries assume that all early-stage breast cancer is treated the same way after diagnosis; with extensive therapies including surgery, radiotherapy and chemotherapy being standard. Intensity of treatment received is rarely mentioned in the debate.”

The researchers conducted a retrospective analysis of 569 women with screening-detected cancer, 53 women with interval cancers, and 169 women with cancers diagnosed without screening. The researchers compared data on symptoms, mode of detection, tumor pathology, surgical intervention, and adjuvant treatment recommendations for the cohort using medical records. 

Study results showed that women in the active screening group were less likely to have invasive cancers and had a higher concentration of lower- stage cancers than women in the not-recently-screened group. Furthermore, the researchers found that among active screeners with invasive cancers, procedures including mastectomy, axillary dissections, adjuvant chemotherapy, and post-mastectomy radiotherapy. 

“Women diagnosed with early-stage breast cancer who are participating in a population based screening program are less likely to receive mastectomy and/or axillary dissection, less likely to receive adjuvant chemotherapy and less likely to receive post-mastectomy radiotherapy,” Dr Machalek and colleagues concluded. “These differences in treatment intensity should be considered in the debate surrounding mammographic screening.”

—David Costill