An interview with: Adri Voogd PhD, Associate Professor of Clinical Epidemiology, Faculty of Health, Medicine and Life Sciences, Maastricht University, Maastricht, The Netherlands
MILAN, Italy—Although outcomes following breast conserving surgery (with or without radiotherapy) for ductal carcinoma in situ (DCIS) are excellent, it is still not clear which cases would never have progressed in all events.
A 30-year-long population-based epidemiology study reported to the 14th European Breast Cancer conference held in Milan has now brought some granular detailed data showing that breast conserving therapy had become increasingly effective in preventing the emergence of breast cancer over the long term, but that clinical judgement is still needed to balance the benefits against the risks and costs of intervening.
The population-based, Netherlands Cancer Registry retrospective cohort study of 25,719 women with DCIS diagnosed from 1989 up to 2021 (all of whom were treated with standard conservative therapy) found there were both successes and limitations with the current standard of care for DCIS.
Surprisingly, long-term risk appeared to have been unrelated to tumor grade. Also: despite a continuing improvement in outcomes during this time period, the investigators concluded that specific molecular predictors of outcome still needed to be identified to distinguish intrinsically low-risk tumors (that did not require even conservative therapy) from those that carry a higher risk, and are highly likely to benefit from breast conserving surgery and radiotherapy.
After reporting the study findings in Milan, study author Adri Voogd PhD, Associate Professor of Clinical Epidemiology in the Faculty of Health, Medicine and Life Sciences at Maastricht University, Maastricht, The Netherlands, talked with Peter Goodwin.
Adri Voogd INTERVIEW
IN (GOODWIN): “Breast conserving therpy was ………” OUT: “….. for the Audio Journal of Oncology, I’m Peter Goodwin.” 15:53 secs
2024 EBCC, Milan Mini Oral session, Abstract 13:
https://event.eortc.org/ebcc14/wp-content/uploads/sites/31/2024/03/EBCC14-Abstract-Book.pdf
https://www.nature.com/articles/s41416-024-02785-6
https://www.ejcancer.com/article/S0959-8049(24)00209-0/fulltext
Abstract:
“Invasive recurrence after breast conserving treatment of ductal carcinoma in situ of the breast in the Netherlands between 1989 and 2021: Time trends and the association with tumour grade”
Authors:
- O’Leary1, L. Duijm2, L. Boersma3, M. van der Sangen4, L. de Munck5, J. Wesseling6, R.J. Schipper7, A. Voogd1. 1Maastricht University, Department of Epidemiology, Maastricht, Netherlands; 2Canisius Wilhelmina Hospital, Department of Radiology, Nijmegen, Netherlands; 3Maastricht University Medical Centre, Department of Radiation Oncology MAASTRO, Maastricht, Netherlands; 4Catharina Hospital, Department of Radiation Oncology, Eindhoven, Netherlands; 5Netherlands Comprehensive Cancer Organization, Department of Research and Development, Utrecht, Netherlands; 6The Netherlands Cancer Institute, Department of Pathology, Amsterdam, Netherlands; 7Catharina Hospital, Department of Surgery, Eindhoven, Netherlands
Background:
The aim of this study was to provide insight in trends and up-to- date figures of the risk of invasive ipsilateral breast cancer (iIBC) after breast conserving surgery (BCS) of ductal carcinoma in situ (DCIS) with or without adjuvant radiotherapy (RT) and to compare these figures with the risk to develop an invasive breast cancer in the contralateral breast (iCBC). A second aim was to analyze the association between DCIS grade and the risk of iIBC and to compare DCIS grade with the histological grade of the subsequent iIBC.
Patients and Methods:
In this population-based, retrospective cohort study, the Netherlands Cancer Registry collected information on 25,719 women with DCIS diagnosed in the period 1989–2021 who underwent BCS. Of these 19,034 (74%) received adjuvant radiotherapy. Kaplan-Meier and Cox multivariable regression analyses were performed.
Results:
1,135 patients experienced an iIBC. The 10-year cumulative iIBC incidence rates for patients diagnosed in the periods 1989–1998, 1999–2008 and 2009–2021 and undergoing BCS only were 12.6%, 9.0% and 5.0% (P < 0.001), respectively. For those undergoing BCS with RT these figures were 5.7%, 3.7%% and 2.2%, respectively (P < 0.001). The 10-year iCBC rates remained stable: 4.4%, 5.5% and 4.5%, respectively, for the periods 1989– 1998, 1999–2008 and 2009–2021 (P = 0.24).
In the multivariable analysis, no statistically significant association was found between the grade of DCIS and the risk of iIBC, neither for the patients undergoing BCS only, nor for those undergoing BCS with RT; the hazard ratio’s for iIBC for DCIS grade 3 versus DCIS grade 1 were 1.11 (95% CI 0.84–1.48, P = 0.47) and 1.04 (95% CI 0.80–1.37, P = 0.75) for the patients who underwent BCS and those undergoing BCS with RT, respectively.
Information on grade of DCIS and grade of the subsequent iIBC was available for 721 patients (63.5%). Of the 189 patients with DCIS grade 1, 23 (12%) developed grade 3 iIBC, compared to 62 (24%) of the 256 patients with DCIS grade 2 and 123 (45%) of the 275 patients with DCIS grade 3 (P < 0.001)
Conclusions:
Since 1989 the risk of iIBC has decreased substantially in patients with DCIS undergoing BCS. Patients currently treated with BCS without RT have a risk of iIBC that is similar to the risk of developing iCBC and patients with adjuvant RT have a risk of iIBC which is 50 percent lower than the risk of iCBC. These low risks of iIBC might have implications for the clinical follow-up of patients with DCIS, such as the frequency of control visits and mammography. Our findings that DCIS grade is not significantly associated with the risk of iIBC stresses the need to intensify research on the tumour biology of DCIS. First, to identify those lesions that have a high risk to become invasive and recur as poorly differentiated invasive breast cancer and second, to identify the ones that are most sensitive to RT.
No conflict of interest.
European Journal of Cancer 200S1 (2024) 113617
