This letter is in response to the article titled "Contribution of early detection and adjuvant treatments to breast cancer mortality reduction in Catalonia, Spain”, which was recently published in PLoS ONE by Vilaprinyo and colleagues(1). In their study, the authors used a stochastic model to estimate the contribution of screening mammography and "adjuvant treatments" in reducing mortality.

As radiation oncologists residing in Catalonia, we were quite naturally eager to read this paper, particularly to learn more about the contributions of adjuvant radiotherapy. To our surprise, however, we discovered that the authors' use of the term "adjuvant" did not include radiotherapy, which, together with systemic therapy, is one of the main adjuvant treatments for breast cancer(2). Although radiotherapy can be used either as a primary or an adjuvant treatment in many cancers (e.g., prostate cancer), its role in breast cancer is almost exclusively adjuvant.

The importance of radiotherapy in treating breast cancer cannot be understated. Local or locoregional radiotherapy in breast cancer has been proven to reduce the likelihood of recurrence by 50% and cancer-related mortality by one-sixth(3). Moreover, adjuvant radiotherapy is indicated in the vast majority of cases: a review carried out by Delaney et al. (4) concluded that adjuvant radiotherapy is indicated in 83% of patients, and most (although not all) of these patients subsequently undergo radiotherapy (5). Furthermore, as Delaney and colleagues showed in their paper, the adjuvant use of radiotherapy is substantially greater than the other treatments deemed “adjuvant” by Vilaprinyo and collaborators.

Given these facts, we do not understand why the role of radiotherapy was overlooked by Vilaprinyo et al., especially in a study that purports to determine the "contribution of adjuvant treatments" in reducing breast cancer mortality. In our opinion, this important omission calls into question the findings of the study, particularly the improvement in mortality attributed only to systemic treatments.

In short, the crucial role of adjuvant radiotherapy in treating and curing breast cancer is, regrettably, not reflected in the findings of this study. We would welcome a clarification from the authors as to why the vital contribution of radiotherapy in reducing breast cancer mortality was ignored in their study.

Manuel Algara(a), Ferran Guedea(b), and Alfredo Ramos(c)

(a)Head of Department of Radiation Oncology, Parc de Salut Mar (Barcelona, Spain)
(b)Head of Department of Radiation Oncology, Catalan Institute of Oncology (Barcelona, Spain)
(c)Head of Department of Radiation Oncology, Hospital Universitario Ramon y Cajal (Madrid, Spain)


Acknowledgements:
We wish to thank Bradley Londres for his assistance in improving the text.

REFERENCES
1. Vilaprinyo E, Puig T, Rue M. Contribution of Early Detection and Adjuvant Treatments to Breast Cancer Mortality Reduction in Catalonia, Spain. PLoS One. 2012 Jan 17;7(1).
2. Violet JA, Harmer C. Breast Cancer: Improving Outcome Following Adjuvant Radiotherapy. Br J Radiol. 2004 Oct 1;77(922):811–20.
3. Darby S, McGale P, Correa C, Taylor C, Arriagada R, Clarke M, et al. Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials. Lancet. 2011 Nov 12;378(9804):1707–16.
4. Delaney G, Barton M, Jacob S. Estimation of an optimal radiotherapy utilization rate for breast carcinoma: a review of the evidence. Cancer. 2003 Nov 1;98(9):1977–86.
5. Jaén Olasolo J, Alonso Redondo E, Expósito Hernández J, de las Peñas Cabrera MD, Cabrera Roldán P. Evidence-based estimation and radiotherapy utilisation rate in Andalusia. Clin Transl Oncol. 2007 Dec;9(12):789–96.