Letter to the Editor Does axillary lymph node dissection impact survival in patients with breast cancer and isolated tumour cells or micrometastasis in sentinel node? Mina M.G. Youssef a,b, *, Diane Cameron a , Sisse Olsen a , Douglas Ferguson a a Department of Breast Surgery, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK b Department of Surgical Oncology, National Cancer Institute e Cairo University, Egypt Received 19 November 2016; accepted 3 January 2017 Dear Editor, We read with interest the article titled ‘Impact of completion axillary lymph node dissection in patients with breast cancer and isolated tumour cells or micro- metastasis in sentinel nodes’ [1], published in your October 2016 issue. We agree with your findings that micrometastasis and isolated tumour cells (ITC) found in the sentinel node indicate planning a different treatment strategy of those patients. In your article, you seem to suggest that axil- lary lymph node dissection improves survival in patients with micrometastasis and not with ITC. We have recently conducted a similar study to yours on a similar cohort of patients [2]. We agree that there is a difference in outcome in patients who are found to have micrometastasis in the sentinel node. But there is not enough evidence to suggest that axillary lymph node dissection (ALND) affects the survival. Thex recent International Breast Cancer Study Group (IBCSG) 23-01 study didn’t show any statistical difference in disease-free survival between patients who had ALND and those who didn’t after micrometastasis was found in the sentinel node [3]. The morbidity associated with ALND, namely lym- phoedema, is well established in the literature compared to sentinel node biopsy [4]. However, the micrometastases and isolated tumor cells: relevant and robust or rubbish? (MIRROR) study showed that patients with micrometastasis and ITC who didn’t receive systemic treatment had a higher event rate than those who did not [5]. In your study, although you have matched the two groups of patients for different adjuvant treatment, it is not very clear which group of patients received radio- therapy to the axilla. You have mentioned that the pa- tients who had breast conserving surgery invariably had adjuvant radiotherapy. In the mastectomy patients’ cohort, the post-operative radiotherapy decision was left to the clinician’s decision. It is not clear, though, how many patients in either group had the radiotherapy field involving the axilla. In our study, there was also statistically significant effect on overall survival (OS) noticed with patients where radiotherapy field was extended to tangentially include the axilla. This result correlates with the American College of Surgeons Oncology Group (ACOSG) Z-001 study results where all patients reportedly received some * Corresponding author: Breast Surgery Department, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, EX2 5DW, Exeter, UK. E-mail address: Mina.youssef@nhs.net (M.M.G. Youssef). http://dx.doi.org/10.1016/j.ejca.2017.01.016 0959-8049/ª 2017 Elsevier Ltd. All rights reserved. Available online at www.sciencedirect.com ScienceDirect journal homepage: www.ejcancer.com European Journal of Cancer 75 (2017) 167e168