Abstract P5-02-03: Incidental radiographic findings at the time of breast cancer diagnosis
Authors: Brothers JM , Kidwell KM , Brown RK , Henry NL 
Published: May 2016

Background: Perioperative staging imaging to evaluate for distant metastases is frequently performed in patients with newly diagnosed breast cancer, despite clinical guidelines recommending against their routine use in stage I and II disease. In addition, recent technological advances in imaging have led to increased sensitivity for findings, many of which are unrelated to breast cancer. We assessed whether the presence of incidental findings on staging imaging is associated with a higher risk of breast cancer recurrence.

Patients and Methods: A retrospective review of staging imaging for distant metastases was performed in 340 patients with stage II or III invasive breast cancer diagnosed in 2008-2009 at a large academic medical center. Data related to patient demographics, pathology, treatment, and recurrence were abstracted from the electronic medical record. Kaplan Meier curves and Cox proportional hazards models were used to assess the association between the presence of incidental findings and time to disease recurrence.

Results: A total of 169 of 340 patients (49.7%) underwent staging evaluation for distant metastases (CT chest, CT abdomen/pelvis, bone scan, and/or PET-CT). Of these, 146 (86.4%) had at least one suspicious or indeterminate radiographic finding. To clarify these findings, 73 (43.2%) patients underwent follow-up imaging or procedures. Nineteen patients were diagnosed with metastatic disease, 18 of whom were initially thought to have stage III disease and one was thought to have stage II disease. In the 127 patients without definite evidence of metastatic disease who underwent staging imaging, 32 were diagnosed with disease recurrence. With median follow-up of 4.9 years, the presence of indeterminate or suspicious findings at diagnosis was not associated with a significant difference in time to disease recurrence, adjusted for stage, hormone receptor status, and HER2 status (HR 1.44, 95% CI 0.51-6.03, p=0.55).

Time to Disease Recurrence by Imaging ModalityImaging Modality# With Indeterminate or Suspicious Finding(s)# Without Indeterminate or Suspicious Finding(s)Hazard Ratio95% Confidence Intervalp-valueAll Patients without mets at diagnosis127231.440.51-6.030.55CT Chest83521.890.80-4.460.15CT Abdomen/Pelvis91451.380.63-3.040.43Bone Scan351231.040.44-2.460.93

Time to Disease Recurrence by Type of Radiographic AbnormalityType of Abnormal Finding# With Indeterminate or Suspicious Finding(s)# Without Indeterminate or Suspicious Finding(s)Hazard Ratio95% Confidence Intervalp-valuePulmonary nodules70661.650.76-3.580.20Liver lesions46911.720.83-3.600.15Borderline or enlarged lymph nodes201190.570.17-1.960.37

Conclusions: Staging imaging for distant metastases frequently reveals indeterminate findings, whose presence was not associated with a significant risk of disease recurrence in this analysis. Due to low yield for the diagnosis of metastases, staging imaging should not routinely be performed in stage II breast cancer patients.

Citation Format: Brothers JM, Kidwell KM, Brown RK, Henry NL. Incidental radiographic findings at the time of breast cancer diagnosis. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-02-03.