Six-Month Intervals for Post-Lumpectomy Mammography Do Not Improve Detection Rates for Breast Cancer Recurrence
(ChemotherapyAdvisor) – Scheduling follow-up mammography every 6 months after breast-conserving treatment (BCT) offers little benefit over a schedule of annual follow-up mammography for breast cancer survivors, according to a retrospective single-institution study published in the Journal of Surgical Oncology.
“Mammography yield of cancer in the study population was not greater than the general population,” and there was “no difference” in tumor recurrence detection rates among patients complying with 6-month follow-up recommendations, reported senior author David McNaul, MD, of the University of Missouri's Department of Radiology in Columbia, MO, and coauthors.
The authors studied medical records of 399 patients who underwent BCT lumpectomies between 1997 and 2009, and who were followed for 2 years after surgery. Cancer yields from follow-up unilateral mammography were compiled and two comparisons were made: First, BCT patients' mammography-detected tumor recurrence was compared to mammography cancer yields in the general screening population. Second, yields were compared between BCT patients who were compliant or noncompliant with instructions to undergo follow-up mammography every 6 months for 2 years.
Yields were similar in both the BCT follow-up population and the general screening population and the study found “no difference between the compliant and noncompliant groups regarding tumor recurrence,” the authors reported. In the group of 67 noncompliant patients, no local tumor recurrences were identified.
Among the 399 patients instructed to undergo follow-up mammography every 6 months instead of annually after BCT, the authors noted, “the extra interval unilateral mammograms (at 6 and 18 months) only detected one local recurrence. Based on the 6-month surveillance mammography schedule, a large number of additional mammograms were performed without obvious benefit.”
“Mammography yield was 0.94 and 2.87 per 1,000 (95% CI: 0.0-0.0028) for the first and second years, respectively, following surgery,” they noted.
The study's findings are consistent with ASCO's guidelines, which recommend annual mammography after BCT, rather than the every-6-months follow-up mammography recommendations observed at some cancer centers like their own, the authors concluded.