Which women are more likely to avoid re-screening mammographies?

Women who get a false-positive result on a mammogram are less likely to return for future screening. And the problem is exacerbated among those who are asked to return for short-interval follow-up or biopsy, according to a study using data from the Breast Cancer Surveillance Consortium (BCSC). Details were published in Annals of Internal Medicine.False-positive results are common. They occur in 10%-to-12% of women aged 40-to-49 years. But after 10 years of annual screening, more than half (50%-to-60%), of women have at least one recall due to a false-positive, and 7%-to-12% get at least one recommendation for a biopsy because of a false-positive.Previous studies of the impact of false-positive biopsies have shown mixed results. Some suggested there were lower rescreening rates after a false-positive than a true-negative mammography result, while others suggested there were higher rescreening rates, the researchers wrote.They conducted a study to evaluate the association between screening mammography results and the likelihood of women going back for screening later on. The researchers looked at various mammography results recorded in the BCSC. These included a true-negative result or false-positive recall with a recommendation for immediate additional imaging only, short-interval follow-up, or biopsy from one or two screening mammograms. Race and ethnicity, age group, and time since last mammogram were also taken into account.The data used were for all screening mammograms that were performed from early January 2005 to the end of December 2017. The focus was on women aged 40-to-73 years with at least 30 months of data collection from 177 breast imaging facilities that were part of the BCSC. Those with a breast cancer diagnosis were excluded.The final study cohort included in the analyses consisted of 3,529,825 screening examinations in 1,053,672 women. Sociodemographic information was collected too. The primary outcome was a return to routine screening within nine-to-30 months of each screening examination.False-positive results were defined as an initial assessment of: 0, meaning ‘needs additional imaging evaluation;’ 3, meaning ‘probably benign;’ 4 or ‘suspicious abnormality;’ or 5 ‘highly suggestive of cancer.’ “False-positive results were further divided on the basis of the final assessment after any imaging work-up occurring within 90 days,” the study said.The study population had a total of 3,184,482 true negatives and 345,343 false positives. The mean age at mammography was 55.6 years, and most screening examinations, 71%, were in women who were white. A total of 29% of the women were aged 40 to 49 years and 35.8% were aged 50 to 59. Over half, 64%, of the screening mammograms were done on women who had had a mammogram sometime in the previous 18 months. Overall, 9.8% of screening mammograms were false-positives. Of these, 5.8% underwent immediate additional imaging only, 2.7% were recommended for short-interval follow-up, and 1.3% were recommended for biopsy. The results showed that false positive results were more common among Black, Hispanic or Latina, and other multiracial women, and were less common among Asian women than white women. False-positive results were also more common among those who underwent their first mammograms and in women with very dense breasts.The percentage of screening mammograms with false-positive results increased as age decreased and time since the last mammogram increased.The women who were most likely to return for screening were those had a true-negative screening result, followed by those with a false-positive recall for additional imaging only, then a biopsy recommendation. Women were least likely to return for screening if they had a short interval follow-up recommendation. Differences persisted during the five-year follow-up period, the study said. Overall, three-quarters of women returned for screening within nine-to-30 months of a screening examination, and this percentage varied according to their screening result. Women were most likely to return after a true-negative result, 76.9%. There was a small decrease in the probability of returning after a false-positive recall with immediate additional imaging only. Women were significantly less likely to return after a false positive with a recommendation for short interval follow-up or biopsy than after a true-negative result. Time since last mammogram was the risk factor most strongly associated with the probability of not returning to screening within nine-to-30 months, the study said.The results also showed that women who underwent two screening mammograms within five years, and who had a false-positive result on the first, were less likely to return for a third screening regardless of whether the second screening result was a true negative or a false-positive.The findings were associative and the researchers noted that “We did not investigate reasons that women discontinued screening.” But, they suggested that offering same-day interpretation and diagnostic work-up of screening mammography might decrease the anxiety and inconvenience associated with having to return for another visit.“It is important for physicians to carefully explain false-positive results to their patients, reassure them that the result was negative, and stress the importance of continued screening,” they said.An accompanying editorial in the same journal offered commentary on the study. Drs. Neha Pathak and Michelle Beth Nadler, both from Princess Margaret Cancer Centre and University of Toronto said that the study was well-conducted and that it “highlights an important concern of the impact of mammography screening on future adherence. It adds to past studies by differentiating adherence to screening based on need for additional imaging, follow-up, and biopsy and considering differences based on clinical and demographic characteristics.”However, a limitation, when it came to associations with race, was that it did not include socioeconomic and related factors, resulting in an incomplete picture.“Future studies may require further detail to understand the disparities and their underlying reasons,” it said.It also stated that there is a greater likelihood of false positives in women aged 40-to-49 years because breast density tends to be higher before menopause.

Which women are more likely to avoid re-screening mammographies?

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