Differences in breast cancer diagnosis by patient presentation in Ontario: a retrospective cohort study

BACKGROUND

In Ontario, patients with breast cancer typically receive their diagnoses through the Ontario Breast Screening Program (OBSP) after an abnormal screen, through screening initiated by a primary care provider or other referring physician, or through follow-up of symptoms by patients' primary care providers. We sought to explore the association of the route to diagnosis (screening within or outside the OBSP or via symptomatic presentation) with use of OBSP-affiliated breast assessment sites (O-BAS), wait times until diagnosis or treatment, health care use and overall survival for patients with breast cancer.

METHODS

In this retrospective cohort study, we used the Ontario Cancer Registry to identify adults (aged 18-105 yr) who received a diagnosis of breast cancer from 2013 to 2017. We excluded patients if they were not Ontario residents or had missing age or sex, or who died before diagnosis. We used logistic regression to evaluate factors associated with categorical variables (whether patients were or were not referred to an OBAS, whether patients were screened or symptomatic) and Cox proportional hazards regression to identify factors associated with all-cause mortality.

RESULTS

Of 51 460 patients with breast cancer, 42 598 (83%) received their diagnoses at an O-BAS. Patients whose cancer was first detected through the OBSP were more likely than symptomatic patients to be given a diagnosis at an O-BAS (adjusted odds ratio 1.68, 95% confidence interval [CI] 1.57 to 1.80). Patients screened by the OBSP were given their diagnoses 1 month earlier than symptomatic patients, but diagnosis at an O-BAS did not affect the time until either diagnosis or treatment. Patients referred to an O-BAS had significantly better overall survival than those who were not referred (adjusted hazard ratio 0.73, 95% CI 0.66 to 0.80).

INTERPRETATION

Patients screened through the OBSP were given their diagnoses earlier than symptomatic patients and were more likely to be referred to an O-BAS, which was associated with better survival. Our findings suggest that individuals with signs and symptoms of breast cancer would benefit from similar referral processes, oversight and standards to those used by the OBSP.

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

OBJECTIVE

To determine the frequency of incidental breast findings reported on chest CT for which breast imaging follow-up is recommended, the follow-up adherence rate, and the breast malignancy rate. The relationship between strength of recommendation verbiage and follow-up was also explored.

METHODS

A retrospective review was conducted of chest CT reports from July 1, 2018, to June 30, 2019, to identify those with recommendation for breast imaging follow-up. Patients with recently diagnosed or prior history of breast malignancy were excluded. Medical records were reviewed to evaluate patient adherence to follow-up, subsequent BI-RADS assessment, and diagnosis (if tissue sampling performed). Adherence was defined as diagnostic breast imaging performed within 6 months of CT recommendation. Chi-square and Mann-Whitney U tests were used to determine statistical significance of categorical and continuous variables, respectively.

RESULTS

A follow-up recommendation for breast imaging was included in chest CT reports of 210 patients; 23% (48/210) returned for follow-up breast imaging. All patients assessed as BI-RADS 4 or 5 underwent image-guided biopsy. Incidental breast cancer was diagnosed in 15% (7/48) of patients who underwent follow-up breast imaging as a result of a CT report recommendation and 78% (7/9) of patients undergoing biopsy. There was no significant difference in follow-up adherence when comparing report verbiage strength.

CONCLUSION

It is imperative that incidental breast findings detected on chest CT undergo follow-up breast imaging to establish accurate and timely diagnosis of breast malignancy. Outreach to referring providers and patients may have greater impact on the diagnosis of previously unsuspected breast cancer.

General Review on the Current Management of Incidental Findings on Cross-Sectional Imaging: What Guidelines to Use, How to Follow Them, and Management and Medical-Legal Considerations

"Incidentalomas" are a common part of daily practice for radiologists, and knowledge of appropriate management guidelines is important in ensuring that no potentially clinically relevant findings are missed or are lost to follow-up in asymptomatic patients. Incidental findings of the brain, spine, thyroid, lungs, breasts, liver, adrenals, spleen, pancreas, kidneys, bowel, and ovaries are discussed, including where to find guidelines for management recommendations, how to follow them, and medical-legal considerations.

Incidental Breast Findings on Computed Tomography and MR Imaging

Computed tomography (CT) and magnetic resonance (MR) imaging may demonstrate a wide variety of incidental findings in the breast, including primary breast carcinoma, the second most common cancer in women. It important to recognize the spectrum of pathologic conditions in order to properly assess the need for further workup. Some findings may be diagnosed as benign on the basis of CT/ MR imaging and clinical history alone, whereas others will require evaluation with dedicated breast imaging and possibly biopsy. This article serves to guide radiologists' management of the wide spectrum of incidental breast findings encountered on cross-sectional imaging.

The effects of incidental findings from whole-body MRI on the frequency of biopsies and detected malignancies or benign conditions in a general population cohort study

Magnetic resonance imaging (MRI) yields numerous tumor-related incidental findings (IFs) which may trigger diagnostics such as biopsies. To clarify these effects, we studied how whole-body MRI IF disclosure in a population-based cohort affected biopsy frequency and the detection of malignancies. Laboratory disclosures were also assessed. Data from 6753 participants in the Study of Health in Pomerania (SHIP) examined between 2008 and 2012 were utilized. All underwent laboratory examinations and 3371 (49.9%) a whole-body MRI. Electronic biopsy reports from 2002 to 2017 were linked to participants and assigned to outcome categories. Biopsy frequency 2 years pre- and post-SHIP was investigated using generalized estimating equations with a negative-binomial distribution. Overall 8208 IFs (laboratory findings outside reference limits: 6839; MRI: 1369) were disclosed to 4707 participants; 2271 biopsy reports belonged to 1200 participants (17.8%). Of these, 938 biopsies occurred pre-SHIP; 1333 post-SHIP (event rate/100 observation years = 6.9 [95% CI 6.5; 7.4]; 9.9 [9.3; 10.4]). Age, cancer history, recent hospitalization, female sex, and IF disclosure were associated with higher biopsy rates. Nonmalignant biopsy results increased more in participants with disclosures (post-/pre-SHIP rate ratio 1.39 [95% CI 1.22; 1.58]) than without (1.09 [95% CI 0.85; 1.38]). Malignant biopsy results were more frequent post-SHIP (rate ratio 1.74 [95% CI 1.27; 2.42]). Biopsies increased after participation in a population-based cohort study with MRI and laboratory IF disclosure. Most biopsies resulted in no findings and few malignancies were diagnosed, indicating potential overtesting and overdiagnosis. A more restrictive policy regarding IF disclosure from research findings is required.

Incidence and outcomes of incidental breast lesions detected on cross-sectional imaging examinations

The aim of this study was to determine the frequency and outcomes of incidental breast lesions detected on nonbreast specific cross-sectional imaging examinations. A retrospective review of the medical records was performed to identify all patients without a known history of breast cancer, who had an incidentally discovered breast lesion detected on a nonbreast imaging examination performed at our institution between September 2008 and August 2012 for this IRB-approved, HIPAA compliant study. Outcomes of the incidental lesions were determined by follow-up with dedicated breast imaging (mammography, breast ultrasound, and/or breast MRI) or results of biopsy, if performed. Imaging modality of detection, imaging features, patient age, patient location at the time of the nonbreast imaging examination, type of follow-up, and final outcome were recorded. Rates of malignancy were also calculated, and comparison was made across the different cross-sectional imaging modalities. Kruskal-Wallis and Fisher's exact tests were used to identify factors associated with an increased rate of malignancy. Logistic regression was used to model the risk of malignancy as a function of continuous predictors (such as patient age or lesion size); odds ratios and 95% confidence intervals were obtained. A total of 292 patients with incidental breast lesions were identified, 242 of whom had incidental lesions were noted on computed tomography (CT) studies, 25 on magnetic resonance imaging (MRI), and 25 on positron emission tomography (PET). Although most of the incidental breast lesions were detected on CT examinations, PET studies had the highest rate of detection of incidental breast lesions per number of studies performed (rate of incidental breast lesion detection on PET studies was 0.29%, compared to 0.10% for CT and 0.01% for MRI). Of the 121 of 292 (41%) patients who received dedicated breast imaging work-up at our institution, 40 of 121 (33%) underwent biopsy and 25 of 121 (21%) had malignancy. There was a significantly increased rate of malignancy in older patients (odds ratio: 1.05, 95% CI: 1.02-1.093; P = .006). Additionally, patients with PET-detected incidental breast lesions had a significantly higher rate of malignancy (55%), compared to patients with CT-detected (35%) and MRI-detected (8%) incidental breast lesions (P = .038). The rate of malignancy upon follow-up of incidental breast lesions detected on nonbreast imaging examinations in this retrospective study was 21%, supporting the importance of emphasizing further work-up of all incidentally detected breast lesions with dedicated breast imaging. Additionally, we found that PET examinations had the highest rate of detection of incidental breast lesions and the highest rate of malignancy, which suggests that PET examinations may be more specific for predicting the likelihood of malignancy of incidental breast lesions, compared to CT and MRI.

Breast Imaging Outcomes following Abnormal Thermography

RATIONALE AND OBJECTIVES

The study aimed to determine the outcome of patients presenting for evaluation of abnormal breast thermography.

MATERIALS AND METHODS

Following Institutional Review Board approval, retrospective search identified 38 patients who presented for conventional breast imaging following a thermography-detected abnormality. Study criteria included women who had mammogram and/or breast ultrasound performed for evaluation of a thermography-detected abnormality between January 1, 2000, and December 31, 2015. Patients whose mammograms and ultrasounds were initiated at an outside institution or who did not have imaging at our institution were excluded. Records were reviewed for clinical history, thermography results, mammogram and/or ultrasound findings, and pathology. Mammograms and ultrasounds were prospectively interpreted by one of 14 Mammography Quality Standards Act-certified breast imaging radiologists with 3-30 years of experience. Patient outcomes were determined by biopsy or at least 1 year of follow-up. Patient ages ranged from 23 to 70 years (mean = 50 years).

RESULTS

Ninety-five percent (36 of 38) of patients did not have breast cancer. The two patients diagnosed with breast cancer had suspicious clinical symptoms including palpable mass and erythema. No asymptomatic woman had breast cancer. Negative predictive value was 100%. Of 38 patients, 79% (30 of 38) had Breast Imaging Reporting and Data System (BI-RADS) 1 or 2 assessments; 5% (2 of 38) had BI-RADS 3; and 16% (6 of 38) had BI-RADS 4 (n = 5) or BI-RADS 5 (n = 1) assessments. Two of six patients with biopsy recommendations were diagnosed with breast cancer (Positive predictive value 2 = 33.3%). All findings recommended for biopsy were ipsilateral to the reported thermography abnormality.

CONCLUSIONS

No cancer was diagnosed among asymptomatic women. The 5% of patients diagnosed with cancer had co-existing suspicious clinical findings. Mammogram and/or ultrasound were useful in accurately characterizing patients with abnormal thermography.