Patterns of Breast Imaging Use Among Women with a Personal History of Breast Cancer

Impact of Surveillance Mammography Intervals Less Than One Year on Performance Measures in Women With a Personal History of Breast Cancer

OBJECTIVE

When multiple surveillance mammograms are performed within an annual interval, the current guidance for one-year follow-up to determine breast cancer status results in shared follow-up periods in which a single breast cancer diagnosis can be attributed to multiple preceding examinations, posing a challenge for standardized performance assessment. We assessed the impact of using follow-up periods that eliminate the artifactual inflation of second breast cancer diagnoses.

MATERIALS AND METHODS

We evaluated surveillance mammograms from 2007-2016 in women with treated breast cancer linked with tumor registry and pathology outcomes. Second breast cancers included ductal carcinoma in situ or invasive breast cancer diagnosed during one-year follow-up. The cancer detection rate, interval cancer rate, sensitivity, and specificity were compared using different follow-up periods: standard one-year follow-up per the American College of Radiology versus follow-up that was shortened at the next surveillance mammogram if less than one year (truncated follow-up). Performance measures were calculated overall and by indication (screening, evaluation for breast problem, and short interval follow-up).

RESULTS

Of 117971 surveillance mammograms, 20% (n = 23533) were followed by another surveillance mammogram within one year. Standard follow-up identified 1597 mammograms that were associated with second breast cancers. With truncated follow-up, the breast cancer status of 179 mammograms (11.2%) was revised, resulting in 1418 mammograms associated with unique second breast cancers. The interval cancer rate decreased with truncated versus standard follow-up (3.6 versus 4.9 per 1000 mammograms, respectively), with a difference (95% confidence interval [CI]) of -1.3 (-1.6, -1.1). The overall sensitivity increased to 70.4% from 63.7%, for the truncated versus standard follow-up, with a difference (95% CI) of 6.6% (5.6%, 7.7%). The specificity remained stable at 98.1%.

CONCLUSION

Truncated follow-up, if less than one year to the next surveillance mammogram, enabled second breast cancers to be associated with a single preceding mammogram and resulted in more accurate estimates of diagnostic performance for national benchmarks.

Semiannual Breast US or MRI Screening in Patients with a Personal History of Breast Cancer

Background The wide variability of screening imaging use in patients with a personal history of breast cancer (PHBC) warrants investigation of its comparative clinical effectiveness. While more intensive screening with US or MRI at an interval of less than 1 year could increase early-stage breast cancer detection, its benefit has not been established. Purpose To investigate the outcomes of semiannual multimodality screening in patients with PHBC. Materials and Methods An academic medical center database was retrospectively searched for patients diagnosed with breast cancer between January 2015 and June 2018 who had undergone annual mammography with either semiannual incidence US or MRI screening from July 2019 to December 2019 and three subsequent semiannual screenings over a 2-year period. The primary outcome was second breast cancers diagnosed during follow-up. Examination-level cancer detection and interval cancer rates were calculated. Screening performances were compared with χ2 or Fisher exact tests or a logistic model with generalized estimating equations. Results Our final cohort included 2758 asymptomatic women (median age, 53 years; range, 20-84 years). Among 5615 US and 1807 MRI examinations, 18 breast cancers were detected after negative findings on a prior semiannual incidence US screening examination; 44% (eight of 18) were stage 0 (three detected with MRI; five, with US), and 39% (seven of 18) were stage I (three detected with MRI; four, with US). MRI had a cancer detection rate up to 17.1 per 1000 examinations (eight of 467; 95% CI: 8.7, 33.4), and the overall cancer detection rates of US and MRI were 1.8 (10 of 5615; 95% CI: 1.0, 3.3) and 4.4 (eight of 1807; 95% CI: 2.2, 8.8) per 1000 examinations, respectively (P = .11). Conclusion Supplemental semiannual US or MRI screening depicted second breast cancers after negative findings at prior semiannual incidence US examination in patients with PHBC. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Berg in this issue.

Variation in second breast cancer risk after primary invasive cancer by time since primary cancer diagnosis and estrogen receptor status

BACKGROUND

In women with previously treated breast cancer, occurrence and timing of second breast cancers have implications for surveillance. The authors examined the timing of second breast cancers by primary cancer estrogen receptor (ER) status in the Breast Cancer Surveillance Consortium.

METHODS

Women who were diagnosed with American Joint Commission on Cancer stage I-III breast cancer were identified within six Breast Cancer Surveillance Consortium registries from 2000 to 2017. Characteristics collected at primary breast cancer diagnosis included demographics, ER status, and treatment. Second breast cancer events included subsequent ipsilateral or contralateral breast cancers diagnosed >6 months after primary diagnosis. The authors examined cumulative incidence and second breast cancer rates by primary cancer ER status during 1-5 versus 6-10 years after diagnosis.

RESULTS

At 10 years, the cumulative second breast cancer incidence was 11.8% (95% confidence interval [CI], 10.7%-13.1%) for women with ER-negative disease and 7.5% (95% CI, 7.0%-8.0%) for those with ER-positive disease. Women with ER-negative cancer had higher second breast cancer rates than those with ER-positive cancer during the first 5 years of follow-up (16.0 per 1000 person-years [PY]; 95% CI, 14.2-17.9 per 1000 PY; vs. 7.8 per 1000 PY; 95% CI, 7.3-8.4 per 1000 PY, respectively). After 5 years, second breast cancer rates were similar for women with ER-negative versus ER-positive breast cancer (12.1 per 1000 PY; 95% CI, 9.9-14.7; vs. 9.3 per 1000 PY; 95% CI, 8.4-10.3 per 1000 PY, respectively).

CONCLUSIONS

ER-negative primary breast cancers are associated with a higher risk of second breast cancers than ER-positive cancers during the first 5 years after diagnosis. Further study is needed to examine the potential benefit of more intensive surveillance targeting these women in the early postdiagnosis period.

Surveillance Imaging after Primary Diagnosis of Ductal Carcinoma in Situ

Background Guidelines recommend annual surveillance imaging after diagnosis of ductal carcinoma in situ (DCIS). Guideline adherence has not been characterized in a contemporary cohort. Purpose To identify uptake and determinants of surveillance imaging in women who underwent treatment for DCIS. Materials and Methods A stratified random sample of women who underwent breast-conserving surgery for primary DCIS between 2008 and 2014 was retrospectively selected from 1330 facilities in the United States. Imaging examinations were recorded from date of diagnosis until first distant recurrence, death, loss to follow-up, or end of study (November 2018). Imaging after treatment was categorized into 10 12-month periods starting 6 months after diagnosis. Primary outcome was per-period receipt of asymptomatic surveillance imaging (mammography, MRI, or US). Secondary outcome was diagnosis of ipsilateral invasive breast cancer. Multivariable logistic regression with repeated measures and generalized estimating equations was used to model receipt of imaging. Rates of diagnosis with ipsilateral invasive breast cancer were compared between women who did and those who did not undergo imaging in the 6-18-month period after diagnosis using inverse probability-weighted Kaplan-Meier estimators. Results A total of 12 559 women (median age, 60 years; IQR, 52-69 years) were evaluated. Uptake of surveillance imaging was 75% in the first period and decreased over time (P < .001). Across the first 5 years after treatment, 52% of women participated in consistent annual surveillance. Surveillance was lower in Black (adjusted odds ratio [OR], 0.80; 95% CI: 0.74, 0.88; P < .001) and Hispanic (OR, 0.82; 95% CI: 0.72, 0.94; P = .004) women than in White women. Women who underwent surveillance in the first period had a higher 6-year rate of diagnosis of invasive cancer (1.6%; 95% CI: 1.3, 1.9) than those who did not (1.1%; 95% CI: 0.7, 1.4; difference: 0.5%; 95% CI: 0.1, 1.0; P = .03). Conclusion Half of women did not consistently adhere to imaging surveillance guidelines across the first 5 years after treatment, with racial disparities in adherence rates. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Rahbar and Dontchos in this issue.

Imaging Surveillance Options for Individuals With a Personal History of Breast Cancer: AJR Expert Panel Narrative Review

Annual surveillance mammography is recommended for breast cancer survivors on the basis of observational studies and meta-analyses showing reduced breast cancer mortality and improved quality of life. However, breast cancer survivors are at higher risk of subsequent breast cancer and have a fourfold increased risk of interval breast cancers compared with individuals without a personal history of breast cancer. Supplemental surveillance modalities offer increased cancer detection compared with mammography alone, but utilization is variable, and benefits must be balanced with possible harms of false-positive findings. In this review, we describe the current state of mammographic surveillance, summarize evidence for supplemental surveillance in breast cancer survivors, and explore a risk-based approach to selecting surveillance imaging strategies. Further research identifying predictors associated with increased risk of interval second breast cancers and development of validated risk prediction tools may help physicians and patients weigh the benefits and harms of surveillance breast imaging and decide on a personalized approach to surveillance for improved breast cancer outcomes.

Facility Variability in Examination Indication Among Women With Prior Breast Cancer: Implications and the Need for Standardization

OBJECTIVE

We sought to identify and characterize examinations in women with a personal history of breast cancer likely performed for asymptomatic surveillance.

METHODS

We included surveillance mammograms (1997-2017) in asymptomatic women with a personal history of breast cancer diagnosed at age ≥18 years (1996-2016) from 103 Breast Cancer Surveillance Consortium facilities. We examined facility-level variability in examination indication. We modeled the relative risk (RR) and 95% confidence intervals (CIs) at the examination level of a (1) nonscreening indication and (2) surveillance interval ≤9 months using Poisson regression with fixed effects for facility, stage, diagnosis age, surgery, examination year, and time since diagnosis.

RESULTS

Among 244,855 surveillance mammograms, 69.5% were coded with a screening indication, 12.7% short-interval follow-up, and 15.3% as evaluation of a breast problem. Within a facility, the proportion of examinations with a screening indication ranged from 6% to 100% (median 86%, interquartile range 79%-92%). Facilities varied the most for examinations in the first 5 years after diagnosis, with 39.4% of surveillance mammograms having a nonscreening indication. Within a facility, breast conserving surgery compared with mastectomy (RR = 1.64; 95% CI = 1.60-1.68) and less time since diagnosis (1 year versus 5 years; RR = 1.69; 95% CI = 1.66-1.72; 3 years versus 5 years = 1.20; 95% CI = 1.18-1.23) were strongly associated with a nonscreening indication with similar results for ≤9-month surveillance interval. Screening indication and >9-month surveillance intervals were more common in more recent years.

CONCLUSION

Variability in surveillance indications across facilities in the United States supports including indications beyond screening in studies evaluating surveillance mammography effectiveness and demonstrates the need for standardization.