4 Incidental Breast Cancer on Chest CT: Is the Radiology Report Enough?

Joley Beeler, MD¹; Onalisa Winblad, MD¹; Carissa Walter, MPH¹; Lauren Clark, MS²; Marc Inciardi, MD¹; Ashley Huppe, MD¹; Jason Gatewood, MD¹; Allison Aripoli, MD¹

¹Department of Radiology, University of Kansas Medical and Cancer Centers, Kansas City, KS.

²Department of Biostatistics & Data Science, University of Kansas Medical, Kansas City, KS.

Background

The purpose of this study was to determine the frequency of incidental breast lesions reported on chest CT for which breast imaging follow-up was recommended, the follow-up adherence rate, and the subsequent breast malignancy rate. In addition, the relationship between the strength of follow-up recommendation verbiage and follow-up rate was also explored.

Material and Methods

A retrospective review was conducted of 30,224 chest CT reports at a single academic institution from July 1, 2018, through June 30, 2019, to identify reports containing the word(s) “breast” and/or “mammogram.” Patients with recently diagnosed or known prior history of breast malignancy were excluded. The reports were reviewed to identify those with a recommendation for breast imaging follow-up, patient adherence to the recommendation, the subsequent Breast Imaging Reporting and Data System (BI-RADS) assessment, and diagnosis if tissue sampling was performed. Adherence was defined as follow-up diagnostic breast imaging performed within 6 months of initial CT recommendation.

Results

A follow-up recommendation for breast imaging was included in chest CT reports of 210 patients without prior history or recent diagnosis of breast cancer. Forty-eight patients (23%) received follow-up dedicated breast imaging within 6 months. For these 48 patients, recommendation verbiage in the CT report was absolute in 69% and optional in 31%. The breakdown of BI-RADS assessments following subsequent diagnostic breast imaging was: 5 BI-RADS 1 (10%), 29 BI-RADS 2 (60%), 5 BI-RADS 3 (10%), 6 BI-RADS 4 (13%), and 3 BI-RADS 5 (6%) assessments. All of the patients assessed as BI-RADS 4 or 5 underwent image-guided biopsy with 7 cases of malignancy diagnosed. There was no significant difference in follow-up adherence when comparing report verbiage characteristics (P = .4624; 2 test).

Conclusions

Only 23% of patients with an incidental breast finding on chest CT actually returned for recommended breast imaging indicating a significant opportunity to improve patient outcomes. Incidental breast cancer was diagnosed in 15% (7/48) of patients who underwent follow-up breast imaging as a result of a chest CT report recommendation. In this sample, the strength of recommendation characterized by CT report verbiage (absolute vs optional) did not improve follow-up adherence. Future efforts to track incidental breast findings detected on chest CT with possible referring provider and patient outreach to ensure follow-up may have greater impact on the diagnosis of previously unsuspected breast cancer.

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