Publication-only abstracts (abstract number preceded by an "e"), published in conjunction with the 2018 ASCO Annual Meeting but not presented at the Meeting, can be found online only.
Should radiotherapy be succeed tumorectomy in patients with low risk ductal carcinoma in situ (DCIS) when using Van Nuys Prognostic Index based treatment?
2018 ASCO Annual Meeting
J Clin Oncol 36, 2018 (suppl; abstr e12561)
Author(s): Anna Niwinska, Jacek Galecki, Agnieszka Irena Jagiello-Gruszfeld; Department of Breast Cancer and Reconstructive Surgery, Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland; The M.Sklodowska-Curie Memorial Cancer Center and Institute, Warsaw, Poland; The Maria Sklodowska-Curie Memorial Cancer Centre and Institute, Warsaw, Poland
Background: Selecting patients with low risk DCIS in whom radiotherapy could be safely omitted is still debatable. The Van Nuys Prognostic Index (VNPI) which analyses 4 prognostic factors helps in choosing such subgroup (VNPI score 4-6), neverthless its value is questionable. The aim of study: assess the role of radiotherapy after tumorectomy in patients with low risk DCIS based on VNPI. Methods: 737 consecutive breast DCIS patients were treated at a Cancer Center during 1999-2011 where tumorectomy (T), tumorectomy and radiotherapy (BCT) and mastectomy (M) were respectively performed in 21%, 32% and 47%. The competing risk of recurrence (RR) was investigated in each of these groups. The VNPI scores were then counted retrospectively. In the low risk group of patients with VNPI scores of 4-6, the RR was compared between those treated only with tumorectomy and with BCT. Cox multivariate analysis assessed the effect of radiotherapy on RR. Results: The 10-year RR of T, BCT and M treated patients were respectively 25%, 12% and 2.5% whereas after 15 years it respectively became 28%, 24% and 3%. In patients with VNPI scores of 4,5 and 6 treated with T and BCT, the competing RR at 10 years was respectively 22% and 2%. Cox multivariate analysis confirmed that radiotherapy decreased the local RR by a factor of 3 in patients with DCIS (HR 0.311). Conclusions: Patients scoring 4-6 VNPI points treated only with T showed a high risk of recurrence which constantly grew during 15 years of observation. Radiotherapy decreases the risk of RR even in this low risk group. Such patients should be informed about the local RR and should take part in radiotherapy treatment decision -making. New biological markers are thus needed to more precisely assess RR in DCIS patients.
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