Follow-up in breast cancer care: guidelines and individual risks

The aim of this study was to investigate how breast cancer follow-up in the Netherlands changed during the COVID-19 pandemic, compared to 2018-2019, and to what extent follow-up during the pandemic corresponded to the patient risk of recurrence. During the early phase of the pandemic the Dutch Society for Surgical Oncology (NVCO) issued a report with recommendations on how follow-up could be postponed, as a guidance for the pandemic, based on a low, intermediate or high risk of recurrence. In this study we investigated to what extent this advice was followed. A dataset of 33160 women diagnosed with primary invasive breast cancer between January of 2017 and July of 2021 was selected from the Netherlands Cancer Registry (NCR) and Dutch Hospital Data (DHD). The pandemic, 2020 and weeks 1-32 of 2021, was divided into six periods (A to F), based on the number of hospitalized COVID patients in the Netherlands. The five-year risk of locoregional recurrence (LRR) was determined for each patient with the INFLUENCE nomogram. The LRR risk was compared to the risk groups from the NVCO report with a Kruskal-Wallis test. The percentage of patients who received a mammogram during period A to F was compared to the same periods of 2018-2019 with a chisquared test. Correlation between the LRR risk, and if patients had a mammogram, was investigated with logistic regression. This analysis was repeated separately for the risk groups. Correlation between the LRR risk, and time intervals between surgery and the first and second mammogram was analyzed using cox proportional hazard models, this was also repeated for the risk groups. There was a significant difference in LRR risk between the NVCO risk groups. In the low-risk group (n=7673), 86 patients (1.1%) had a risk >5%. In the intermediate risk group (n=19197), 18364 patients (95.7%) had a risk of < 5%, and 65 patients (0.34%) had a risk of >10%. In the high-risk group (n=2674), 2365 patients (88.4%) had a risk < 10%. The percentage of patients who received a mammogram was significantly lower in periods B to F of the pandemic. Logistic regression showed a negative correlation between the risk of LRR and if patients had a mammogram in 2020 (OR 0.93) and 2021 (OR 0.93). There was also a negative correlation between the risk groups and mammography in 2020 (OR 0.92 for intermediate and 0.80 for high), and for the risk groups and mammography in 2021 (OR 0.98 for intermediate and 0.95 for high). There was no significant impact of LRR risk, or risk group, on time intervals between mammograms. During the pandemic, patients with a higher LRR risk, or a higher risk according to NVCO advice, had lower odds of having a mammogram. If the advice would have been followed, in 0.5% of the patients scheduled for follow-up, the recommendation was to postpone in contrast to a high estimation of the individual risk. For 62.7%, a follow-up was recommended, despite a low estimated individuals risk. Because the number of high-risk patients is relatively low, individual risk prediction could be supportive, in case of future restrictions. This way the high-risk patients can be identified and prioritized for follow-up, and can also be encouraged to come to the hospital.

The Quest for Outpatient Mastectomy in COVID-19 Era: Barriers and Facilitators.

Background: The rate of inpatient mastectomies remains high despite multiple studies reporting favourably on outpatient mastectomies. Outpatient mastectomies do not compromise quality of patient care and are more efficient than inpatient care. The objective of this study was to evaluate the feasibility of outpatient mastectomy. Materials and Methods: Implementation of an outpatient mastectomy program was evaluated in a retrospective study. All patients who underwent mastectomy between January 2019 and September 2021 were included. Results: 213 patients were enrolled in the study: 62.4% (n = 133) outpatient mastectomies versus 37.6% (n = 80) inpatient mastectomies. A steady rise in outpatient mastectomies was observed over time. The second quarter of 2020, coinciding with the first COVID-19 wave, showed a peak in outpatient mastectomies. The only significant barrier to outpatient mastectomy proved to be bilateral mastectomy. Unplanned return to care was observed in 27.8% of the outpatient versus 36.3% of the inpatient mastectomies (P=0.198); the reason for unplanned return of care was similar in both groups. Conclusions: Outpatient mastectomy is shown to be feasible and safe with a steady increase during the study period. A barrier to outpatient mastectomy was bilateral mastectomy. Incidence of unplanned return to care or complications did not differ significantly between the outpatient and inpatient cohorts.

The impact of the COVID-19 outbreak on breast cancer stage in the Netherlands by screening status

Introduction: The COVID-19 outbreak led to the suspension of the Dutch breast cancer screening program, increased the reluctance of patients to visit the general practitioner (GP), and led to a lack of capacity at the GP. As a consequence, the incidence of breast cancer diagnoses decreased. Objective: This study aimed to investigate the impact of the COVID-19 outbreak on the incidence of different stages of breast cancer, by screening status. Methods: Women diagnosed between January 1st 2017 and February 28th 2021 with primary breast cancer without a history of breast cancer were selected from the Netherlands Cancer Registry. March 1st 2020 till February 28th 2021 was regarded as the COVID-19 period. Breast cancer incidence within this COVID-19 period was calculated by tumor stage and compared with the incidence in 2017/2019 (reference). Incidence was expressed per 100, 000 women aged 18 year or older, living in the Netherlands at the start of the year. Thereafter, the COVID-19 period was divided into four subperiods, based on COVID-19 related events: March-April 2020, May-June 2020, July-August 2020, September 2020-February 2021. Incidence in each of those periods was calculated by tumor stage and compared with the incidence in 2017/2019. Analyses were further stratified by screening status. Incidence of screenS detected tumors was expressed per 100, 000 women aged 50-74 living in the Netherlands at the start of the year. Results: A total of 15, 916 women were diagnosed in 2017, 15, 574 in 2018, 15, 867 in 2019, 13, 497 in 2020 and 2, 532 up to February 2021. Compared to 2017/2019, the incidence of DCIS and stage I-III tumors was statistically significantly lower during the COVID-19 period (32%, 24%, 9% and 11% respectively) (Table 1), leading to 603, 1539, 520 and 160 missed diagnoses respectively. The incidence of stage IV tumors was 5% higher, however this was not significant. The incidence of DCIS remained significantly lower throughout the four subperiods, while the incidence of stage I-II tumors was comparable with 2017/2019 in September 2020-February 2021 and the incidence of stage III was comparable with 2017/2019 in both July-August 2020 and September 2020-February 2021. The incidence of DCIS and stage I-II non-screen-detected tumors was significantly lower during March-April 2020 and was comparable with 2017/2019 in the subperiods thereafter. The incidence of DCIS and stage I-IV screen-detected tumors was significantly lower during March 2020-February 2021, with the incidence of DCIS and stage I-III tumors being lower during each subperiod and the incidence of stage IV tumors being lower during May-June 2020. Conclusion: The COVID-19 outbreak led to a decrease in the incidence of DCIS and stage I-III tumor diagnoses, which still lags behind in February 2021. Until February 2021 no stage shift was seen.

Effect of the COVID outbreak on detection of second primary breast cancer and breast cancer recurrences

Introduction: The COVID-19 pandemic led to a decrease in the incidence of breast cancer diagnoses in the Netherlands. This was due to the encouragement to stay at home, a lack of capacity at the general practitioner (GP) and an increased reluctance of patients to visit the GP. Moreover, from the 16th of March the Dutch breast cancer screening program was halted and gradually restarted from June onwards. Part of the follow-up visits for breast cancer survivors were also postponed or changed to an appointment by phone. However, it is not known how this affected the incidence of second primary breast cancer (SPBC) and pathologically confirmed breast cancer recurrences. Objective: To investigate the effect of the COVID-19 pandemic on the diagnosis of SPBC and breast cancer recurrences. Methods: Women diagnosed with a pathological confirmed SPBC or recurrence (locoregional recurrences (LRR) + distant metastasis (DM)) between January 1st 2017 and February 28th 2021 were selected from the Netherlands Cancer Registry, based on diagnoses of the Nationwide Histopathology and Cytopathology Data Network and Archive (PALGA). Patients with a SPBC or recurrence who had their primary breast tumor diagnosed more than five years ago were excluded. March 1st 2020 till February 28th 2021 was regarded as the S COVID-19 period. Incidence was expressed per 100, 000 women, who were diagnosed with breast cancer less than 5 years ago, and who were still alive. Incidence of SPBCs and recurrences was calculated for the total COVID-19 period and for four subperiods, and compared with the corresponding periods in 2017/2019 (averaged). Results: A total of 393 patients were diagnosed with a SPBCs in 2017, 340 in 2018, 299 in 2019, 342 in 2020 and 71 up to February 2021. A total of 447 patients were diagnosed with a recurrence in 2017, 520 in 2018, 516 in 2019, 529 in 2020 and 80 up to February 2021. During the COVID-19 period a total of 449 patients were diagnosed with a SPBCs per 100, 000 breast cancer survivors, this was comparable to the 445 patients diagnosed per year per 100, 000 breast cancer survivors in 2017/2019 (p=0.91) (Table 1). The incidence of SPBCs was significantly lower during March-May 2020 compared to the same period in 2017/2019 (86 vs. 121) (p=0.03), leading to 50 less SPBCs diagnoses. The incidence was higher during June-August 2020 (124 vs. 95), however this was not significant (p=0.09). The incidence of recurrences in the COVID-19 period, and within all four subperiods, was comparable to the incidence in 2017/2019. Conclusion: The COVID-19 pandemic led to a decrease in the detection of SPBCs at the beginning of the pandemic. However, this drop in incidence was caught up in the period thereafter. This might be related to the restart of the regular follow-up visits (partly in real-life consultations), the call to go to the GP in case of complaints and the improved accessibility of the GPs. The incidence of recurrences did not decrease since it includes also DM, which cause worrisome symptoms for which care is sought.

Impact of the COVID-19 outbreak on the treatment strategy of Dutch breast cancer patients

Introduction: The COVID-19 outbreak forced health care services to switch focus to COVID-19 patients, thereby generating pressure on all other health care services, most likely impacting breast cancer care as well. However, the impact of the COVID-19 outbreak on the breast cancer treatment strategy is unknown. Objective: To investigate the impact of the COVID-19 outbreak on the breast cancer treatment strategy. Methods: We selected women diagnosed with breast cancer between January 1st 2018 and June 30th 2020 from the Netherlands Cancer Registry. Women with previous breast cancer or with a synchronous tumor were excluded. The following periods based on COVID-19 related events were analyzed: 2018/2019 (reference), weeks 1-8, weeks 9-12, weeks 13-17, and weeks 18-26 in 2020. Patients were divided into periods based on their date of diagnosis. For patients with DCIS we used logistic regression to investigate the association between period of diagnosis and chance of being treated within six months following diagnosis. For patients with invasive tumors receiving surgery, we used logistic regression to investigate the association between period of diagnosis and chance of receiving a certain type of treatment, adjusting for tumor stage. Furthermore, time length between the following time points were calculated per tumor stage: S 1) diagnosis and first treatment (of any kind), 2) diagnosis and start of neo-adjuvant treatment, 3) diagnosis and operation (no neo-adjuvant treatment was given), 4) end of neo-adjuvant treatment and operation, 5) operation and start of adjuvant systemic treatment, and 6) operation and start of radiotherapy. Time lengths were calculated for each period of 2020 and compared with 2018/2019. Results: A total of 1, 795 DCIS and 11, 785 invasive tumors were diagnosed in 2018, 1, 826 DCIS and 11, 987 invasive tumors in 2019 and 597 DCIS and 4, 566 invasive tumors up to June 2020. Compared to 2018/2019, patients diagnosed with a DCIS were less likely to be treated within six months following diagnosis (ORwks1-8: 0.63, ORwks9-12: 0.50, ORwks18-26: 0.51) (Table). Patients diagnosed with an invasive tumor in weeks 9-12 2020 were less likely to receive neo-adjuvant chemotherapy (ORwks9-12: 0.63), while patients diagnosed thereafter were more likely to receive neo-adjuvant chemotherapy (ORwks13-17: 1.39, ORwks18-26: 1.41). Patients were more likely to receive neo-adjuvant endocrine therapy (ORwks1-8: 1.64, ORwks9-12: 3.14, ORwks13-17: 1.85, ORwks18-26: 1.28), mastectomy (ORwks18-26: 1.32), or adjuvant chemotherapy (ORwks9-12: 1.36), while they were less likely to receive radiotherapy (ORwks18-26: 0.74). Patients receiving a mastectomy for their invasive tumor were more likely to receive an immediate reconstruction (ORwks18-26: 1.57). Compared to 2018/2019, time between diagnosis and first treatment, diagnosis and operation, diagnosis and neo-adjuvant treatment, and operation and adjuvant systemic treatment decreased significantly for patients diagnosed with a stage I-III tumor in weeks 9-12, 13-17 or 18-26. Conclusion: The COVID-19 outbreak affected multiple aspects of the breast cancer treatment strategy and led to a shorter time to therapy, probably due to prioritizing of oncological care and a reduction in the number of patients.