Stromal marker predicting radiotherapy benefit in DCIS Predictive biomarkers are urgently needed to support the individualization of radiotherapy for DCIS. Most efforts have focused on tumor cell features rather than the associated stroma. Our recent study by Strell et al. published in Clinical Cancer Research1 suggests that high expression of the stroma cell marker platelet-derived growth factor receptor beta (PDGFRb) can identify DCIS patients, who do not benefit from adjuvant radiotherapy. Carina Strell, PhD, is Associate Professor in Experimental Pathology
of overtreatment for some, and potentially
sala University in Sweden. Her field of work includes tumor stroma
need to find predictive markers that can be
in the Department of Immunology, Genetics and Pathology at Upp-
interactions driving the evolution and development of radiotherapy resistance in early breast cancer. Arne Östman, PhD, is Professor
of Molecular Oncology in the Department of Oncology and Pathology at Karolinska Institutet, Stockholm, Sweden. His field of work is translational studies on the tumor microenvironment with special emphasis on cancer-associated fibroblasts.
Ductal carcinoma in situ (DCIS), a precursor of invasive breast cancer, represents about 25%
of all breast cancers detected by screening in Europe. Although the prognosis is generally
many, women. Consequently, there is an urgent used to avoid unnecessary or ineffective radiotherapy for DCIS patients.
Most previous studies have focused mainly
on markers in the tumor cells themselves, but
recent findings show that cells of the tumor
microenvironment can also affect both the aggressiveness and therapeutic effects in DCIS
cases. In particular cancer-associated fibrob-
lasts have been demonstrated to influence the
efficacy of radiotherapy in different cell and mouse models.3–6
within ten years of diagnosis.2 The standard tre-
PDGFRb as predictive biomarker In our study, we retrospectively analyzed a lar-
breast-conserving surgery followed by adju-
radiotherapy trial in order to investigate whet-
good, 10-20% of patients suffer a recurrence
atment for DCIS patients today comprises vant whole-breast radiotherapy.
However, DCIS is a heterogeneous disease
with unclear natural history, and it is recognized that the benefits of radiotherapy are highly in-
dividual. Owing to this uncertainty, the present treatment recommendations involve a high risk
BestPractice Nordic / FI / Onkologia / NR. 9 / 2021
ge tissue collection from a Swedish randomized her the stroma cell marker PDGFRb has any
prognostic relevance or could predict the response to adjuvant radiotherapy in DCIS.
The study included 590 patients with primary
DCIS who had undergone breast conserving
surgery. The median follow-up time was 17.4
27
