Prognostic value of axillary lymph node status after neoadjuvant chemotherapy. Results from a multicentre study Nakul Saxena a , Mikael Hartman a,e , Rezal Aziz b , Elisabetta Rapiti f , Nirmala Bhoo Pathy b,h , Siew Eng Lim c , Philip Iau e , Nur Aisha Taib b,g , Robin Schaffar f , Isabelle Neyroud-Caspar f , Cheng Har Yip b,g , Soo Chin Lee c , Helena M. Verkooijen a,d,h, * a Department of Epidemiology and Public Health, National University of Singapore, Block MD3, 16 Medical Drive, Singapore 117597, Singapore b Julius Center University of Malaya, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia c Department of Hematology Oncology, National University Cancer Institute, National University Health Systems, Singapore 119228, Singapore d Department of Radiology, University Medical Center Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands e Department of Surgery, Yong Loo Lin School of Medicine, National University of Singapore, c/o National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074, Singapore f Geneva Cancer Registry, Institute for Social and Preventive Medicine, Geneva University, Switzerland g Department of Surgery, Faculty of Medicine, University Malaya Medical Centre, 50603 Kuala Lumpur, Malaysia h Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, P.O. Box 85500, 3508 GAUtrecht, The Netherlands ARTICLE INFO Article history: Received 7 September 2010 Received in revised form 7 December 2010 Accepted 14 December 2010 Available online 14 January 2011 Keywords: Prognostic value Lymph node status Neoadjuvant chemotherapy ABSTRACT Background: The prognostic value of lymph node involvement after neoadjuvant chemo- therapy for breast cancer is not straightforward. We evaluated whether lymph node involvement is associated with overall survival in patients treated with neoadjuvant che- motherapy and whether Lymph Node Ratio (LNR – ratio of the positive to excised axillary lymph nodes) is a superior prognosticator when compared to ypN status (according to the pTNM classification). Methods: Three hundred and fourteen patients receiving neoadjuvant chemotherapy in Geneva, Singapore or Kuala Lumpur were pooled for analysis. We evaluate the prognostic value of the LNR [zero, low (>0 and <0.2), intermediate (0.2–0.65) and high risk (>0.65)] and ypN staging [ypN0, ypN1, ypN2 and ypN3] with multivariate Cox regression analysis. Results: When using the LNR classification, 88 patients were categorised as zero, 91 as low, 82 as intermediate and 53 as high risk. For classic ypN staging, 88 were ypN0, 126 ypN1, 58 ypN2 and 42 ypN3. Compared to the low risk category, LNR zero corresponded to an adjusted hazard ratio [HRadj] of 0.4 (95%CI, 0.2–0.9), intermediate risk LNR to a HRadj of 1.2 (0.7–2.2) and high risk LNR to a HRadj of 2.7 (1.5–5.0). Similarly, the ypN0 category cor- responded to a HRadj of 0.3 (0.2–0.7), ypN2 to a HRadj 1.1 (0.6–2.0) and ypN3 to a HRadj 2.2 (1.3–3.8) compared to ypN1 patients. 0959-8049/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.ejca.2010.12.009 * Corresponding author: Address: Department of Radiology, University Medical Centre Utrecht, P.O. Box 85500, 3508 GA Utrecht, The Netherlands. Tel.: +65 6516 4988; fax: +65 6779 1489. E-mail address: ephhmv@nus.edu.sg (H.M. Verkooijen). EUROPEAN JOURNAL OF CANCER 47 (2011) 1186 – 1192 available at www.sciencedirect.com journal homepage: www.ejconline.com