A simulation model has predicted that a six-month interruption in breast cancer screening would result in 4100 missed breast cancer cases (including DCIS) in Canada.
During the COVID-19 pandemic, this clinic remained open, ensuring patients could still undergo investigations for breast concerns despite social distancing and other restrictions. Measures adopted during the COVID-19 pandemic were aimed at reducing the number of hospital visits while ensuring appropriate delivery of care. The intent was to triage patients who may need a biopsy based on referral to ensure an entire workup in one visit.
The objective of this study was to assess the impact of the COVID-19 pandemic on patient volumes and treatment timing at this high-volume breast rapid diagnostic centre.
2.1 Study cohort
In this single-center retrospective study, a review of consecutive patients who presented to the GRDC from the start of the declaration of the pandemic on March 12, 2020, until August 31, 2020, was performed and compared to the corresponding time period in 2019. Patients were generally eligible to be referred to the clinic if they had breast imaging that showed a BIRADS 4 or 5 breast lesion or a palpable breast mass that had not been biopsied.
For this study, we included patients who underwent a biopsy with a new diagnosis of stage 0–3 breast cancer. Patients were excluded if they had a biopsy showing benign pathology, if they had recurrent disease, or were found to have metastatic breast cancer. Patients with recurrent breast cancer were excluded as the treatment algorithms often differ and involve additional specialist consultations and diagnostic tests. Patients with metastatic breast cancer were excluded in this study of diagnostic wait times. The demographic details, clinical and pathological disease data (laterality, date of core biopsy, clinical stage, histology, grade, hormone receptor status, pathologic stage), wait times between investigations, diagnosis, treatment, and treatment details (neoadjuvant endocrine/chemotherapy) and surgical details were obtained through a retrospective chart review.
2.2 Outcome measures
The primary outcomes were the number of patients, reasons for referral, the proportion of patients with a cancer diagnosis and wait times for all patients seen in the GRDC during the two time periods. The secondary outcomes included demographics and treatments for patients diagnosed with breast cancer through the GRDC.
We defined three separate wait times for the study cohort within the COVID (2020) and pre-COVID (2019) time periods. Time 1 was from the first imaging abnormality (either performed at an outside facility or through GRDC) to diagnosis (date of core biopsy result), Time 2 was from diagnosis (date of core biopsy result) to surgical consultation, and Time 3 was from surgical consultation to surgery date for patients undergoing upfront surgery.
2.3 Statistical analyses
The proportion of patients was calculated for categorical variables and compared using Chi-square or Fisher’s exact test. In addition, mean and interquartile ranges (IQR) were calculated for continuous variables and were compared using an independent T-test was used for continuous variables. A p-value of less than 0.05 was considered statistically significant. Statistical analyses were performed using SPSS software Version 9.4 for Mac (SAS Institute Inc., Cary, NC).
2.4 Research ethics
This study was approved by the institutional research ethics board.
Table 1Breast imaging investigations performed on all patients who presented to the Gattuso Rapid Diagnostic Centre (GRDC) between March 12 – August 31, 2020 and the comparison time period in 2019 (March 12 – August 31, 2019).
Table 2Demographics and clinical characteristics of patients who were diagnosed with stage 0–3 breast cancer through the Gattuso Rapid Diagnostic Clinic (GRDC) between March 12 – August 31, 2020 and the comparison time period in 2019 (March 12 – August 31, 2019).
this is the first to assess the impact of the presence of a rapid diagnostic centre on breast investigations and treatment during the pandemic.
In Ontario, Canada, there was a complete cessation of breast cancer screening between March to June 2020, with a 99% decrease in volume of mammograms performed compared to the same time period in 2019.
Even when cancer screening resumed, the decrease in volume of screening mammograms completed during the first pandemic wave compared to 2019 persisted.
The volume of screening mammograms did not return to baseline until March 2021, resulting in a backlog of 340,876 screening mammograms.
Despite the change in patient presentation, a lower proportion of GRDC patients were diagnosed with breast cancer during the first six months of the pandemic compared to the similar time frame the year prior. We hypothesize that this was due to patients presenting to the GRDC with breast symptoms (e.g., palpable lesion) during the pandemic period, who would have otherwise been assessed by their family physician and had breast imaging at external facilities. Since our radiology group does not routinely repeat mammograms, patients with benign findings (BIRADS 1, 2, or 3) would not usually be referred to the GRDC for further investigation if patients had been able to access breast imaging. This is reflected by a higher proportion of patients who had mammograms through the GRDC and the lower proportion of patients undergoing biopsy in 2020. We also had a higher proportion of patients undergoing MRIs through our RDC compared to the pre-pandemic period, where patients may have come with an MRI, but an incomplete work-up (e.g., contralateral breast finding, suspicious nodes on MRI that were not biopsied). Therefore, the GRDC represented an avenue for assessing clinical concerns when no other imaging and diagnostic options were readily available.
where wait times from core biopsy to surgery were reduced from 58 to 28 days for patients seen during the pandemic. While these results may be partially explained by the reduction in patient volumes, we believe measures adopted during the COVID-19 pandemic may have contributed to the shortened wait times and can potentially be employed in the long term to reduce surgical wait times. These measures included triaging consults and prioritizing patients who did not have outside imaging requiring review and ensuring additional time when triaging patients who may have needed a biopsy based on referral to ensure an entire workup in one visit. The GRDC also created “add-on” slots for patients seen in breast imaging who needed a biopsy to expedite the pathology and ensure appropriate consultation. Surgical wait times were also preserved at our institution as the hospital endeavored to maintain breast cancer surgical volumes by prioritizing oncologic surgery.
and invasive breast cancer.
showed that patients identified as Black or African American, Asian, or other races were more likely to experience a delay and/or change than Caucasian patients. Information on ethnicity is not routinely collected in our system, and we would not be able to conduct a similar analysis. Lastly, the time of our data collection is relatively short, and we do not have enough data to assess long-term oncologic outcomes or to assess how return to pre-pandemic patient volumes impacted wait times. This study is part of an ongoing project assessing breast cancer outcomes during the COVID-19 pandemic, which may help determine if these reductions in wait times will remain in the post-pandemic era.