ABSTRACT
Introduction: The burden of the COVID-19 pandemic forced the Dutch health care services to discontinue their national screening programs on 16 March 2020 (week 12). For breast cancer, the program invites women aged 50-74 years for biennial screening mammography. From mid-June 2020 (week 25) the breast cancer screening program was resumed, albeit with reduced capacity (max 60%). We aimed to investigate the impact of resuming the screening program on incidence, tumor-, and T-stage of screen- and non-screen-detected ductal carcinoma in situ (DCIS) and invasive breast cancer (IBC) in the Netherlands. Methods: Women, 50-74 years of age, diagnosed with DCIS or IBC in weeks 2-35 of 2018, 2019 and 2020 were selected from the Netherlands Cancer Registry. Weekly incidence of screen- and non-screen-detected tumors was calculated and expressed per 1 million women aged 50-74 years living in the Netherlands. Weeks 2-35 were divided in seven periods, representing separate phases of the pandemic. For each period, incidence of screen- and non-screen-detected tumors was stratified by clinical tumor stage (TNM) and clinical T-stage. Incidence in each period of 2020 was compared with the incidence in the same period of 2018/2019 (averaged). Results: In weeks 2-35, 7,250 patients were diagnosed in 2018, 7,299 in 2019, and 5,300 in 2020. During weeks 2-12 2020 the weekly average incidence of screen-detected tumors was 42/1 million women aged 50-74. In week 13 incidence dropped to 19, and was almost zero during weeks 14-25. Incidence increased to 4 in week 26, when the screening was gradually restarted, and increased to an weekly average of 24 tumors/1 million in weeks 30-35, when screening had restarted in most of the Netherlands. During weeks 14-16, 17-25, 26-29, and 30-35 2020 incidence of screen detected DCIS, stage I-II tumors and T0-2 tumors was lower than in the same period of 2018/2019. Distribution of tumor- and T-stage in newly diagnosed tumors did not differ between the periods (24% DCIS, 57% stage I, 18% stage II, 1% stage III, 1% stage IV;24% T0, 59% T1, 15% T2, 2% T3, 0% T4). During weeks 2-11 2020 the weekly average incidence of non-screen-detected tumors was 38/1 million women aged 50-74. Incidence dropped to 16 in week 14, and increased to an average of 37 tumors per week in weeks 17-35. During weeks 17-25, 26-29, and 30-35 the incidence and distribution of non-screen-detected DCIS, stage I-IV and T0-4 tumors was comparable with 2018/2019 (weekly incidence (distribution): 3 DCIS (9%), 15 stage I (40%), 13 stage II (36%), 3 stage III (7%), 3 stage IV (8%);3 T0 (9%), 17 T1 (45%), 12 T2 (34%), 3 T3 (8%), 2 T4 (5%)). Conclusion: The temporary suspension of the breast cancer screening program reduced the incidence of breast cancer. After resuming screening the incidence did not raise above the incidence in 2018/2019, therefore it is expected that the incidence will rise during the next months. The results to date did not show a shift towards a higher tumor stage or T-stage.
ABSTRACT
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.
ABSTRACT
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.