Data Support Less Frequent Mammograms After Curative Breast Cancer Surgery

Women age 50 and older may not require annual mammograms after curative-intent breast cancer surgery, according to researchers.

The researchers found no significant difference in breast cancer-specific survival, recurrence-free interval, or overall survival between patients who had annual mammograms after surgery and those who had less frequent mammograms.

These findings were presented at the San Antonio Breast Cancer Symposium 2023 by Janet A. Dunn, PhD, of the University of Warwick in Coventry, England.

Dr Dunn said she and her colleagues conducted this study — Mammo-50 — “to determine the optimum frequency and duration of mammographic surveillance.”

The study included 5235 women who were 50 years of age or older, had undergone curative-intent treatment for invasive or non-invasive breast cancer, and were 3 years post-surgery.

The patients were randomly assigned to undergo annual mammograms (n=2618) or less frequent mammograms (n=2617). In the less frequent group, patients had mammograms every other year if they had undergone wide local excision (n=2099), and they had mammograms every 3 years if they had undergone mastectomy (n=518).

The compliance rates were 83% for the annual group and 69% for the less frequent group. Dr Dunn noted that 35% of patients missed mammograms due to the COVID-19 pandemic.

At a median follow-up of 5.7 years, 343 patients (7%) had died — 116 of breast cancer, 93 of another cancer, and 134 of other causes. A total of 345 patients (7%) had invasive breast cancer recurrence, and 252 (5%) had a new non-breast malignancy.

Less frequent mammograms were noninferior to annual mammograms for breast cancer-specific survival, recurrence-free interval, and overall survival.

The 5-year breast cancer-specific survival rate was 98.1% in the annual mammogram group and 98.3% in the less frequent group (hazard ratio [HR], 0.92; 95% CI, 0.64-1.32; P <.0001 at 3% margin; P =.003 at 1% margin).

The 5-year recurrence-free interval was 94.1% in the annual group and 94.5% in the less frequent group (HR, 1.00; 95% CI, 0.81-1.24; P =.006 at 2% margin).

The 5-year overall survival rate was 94.7% in the annual group and 94.5% in the less frequent group (HR, 1.08; 95% CI, 0.87-1.33; P =.008 at 2% margin).

In a quality-of-life assessment, 30% of patients reported no distress, 46% reported low levels of distress, 18% had medium levels of distress, and 6% had high levels of distress. Trends in distress did not differ significantly between the groups.

“Mammo-50 demonstrated that, for patients aged 50 years or older and 3 years post-diagnosis, less repeat mammograms were noninferior to annual, but there is a need to have a mechanism for easy access back into the system for symptom management and ongoing support for a small percentage of patients who may need that,” Dr Dunn said. “Mammo-50 provides evidence for change in clinical practice.”

Disclosures: Dr Dunn said she has no disclosures. One study author declared a relationship with Eli Lilly. No other disclosures were provided.

Reference

Dunn J, Donnelly P, Elbeltagi N, et al. Mammographic surveillance in early breast cancer patients aged 50 years or over: Results from the Mammo-50 non-inferiority trial of annual versus less frequent mammography. Presented at SABCS 2023. December 5-9, 2023. San Antonio, TX. Abstract GS03-02.

This article originally appeared on Cancer Therapy Advisor