He et al. BMC Cancer 2010, 10:681 http://www.biomedcentral.com/1471-2407/10/681 R E S E A R C H A R T I C L E Open Access Initial partial response and stable disease according to RECIST indicate similar survival for chemotherapeutical patients with advanced non- small cell lung cancer Lijie He1, Yuee Teng1, Bo Jin1, Mingfang Zhao1, Ping Yu1, Xuejun Hu2, Jingdong Zhang1, Songbai Li3, Yaling Gao4, Yunpeng Liu1* Abstract Background: Stable disease (SD) has ambiguous clinical significance for patients according to the dominant Response Evaluation Criteria in Solid Tumours (RECIST). The primary aims of the study were: (1) to clarify the clinical significance of SD by comparing the progression-free survival (PFS) of response and SD patients with advanced non-small cell lung cancer (NSCLC) after the first two courses of the standard first-line platinum-based chemotherapy; (2) to explore the relationship between the percentage change in tumour size and PFS among initial SD patients, in order to provide some guidance for clinicians in deciding continuation/termination of the current treatment at a relative early time. Methods: A total of 179 advanced NSCLC patients whose baseline CT image was available for review were included in the study. Another CT image was taken in the initial assessment after chemotherapy. A comparison of PFS between initial partial response (PR) and SD was used to determine whether significant differences exist. The relationship between the early percentage of change in tumour size of initial SD patients and their PFS was investigated. In addition, overall survival (OS), the secondary endpoint in this study, was investigated as well. Results: Patients with initial PR are not significantly distinguished from those with initial SD when their PFS is concerned (median PFS 249 days [95% confidence interval, 187-310 days] versus 220 days [95% confidence interval, 191-248 days], p > 0.05). Their median OS was 364 days (95% confidence interval, 275-452 days) for the initial PR patients versus 350 days (95% confidence interval, 293-406 days) for the initial SD patients, which suggests no significant difference as well p > 0.05). In addition, all the initial SD patients enjoyed similar PFS and OS. Conclusions: Initial PR and SD enjoy similar PFS and OS for patients with advanced NSCLC. Within the initial SD subgroup, different percentages of tumour shrinkage or increase undergo similar PFS and OS. RECIST remains a reliable norm in assessing the effectiveness of chemotherapy for patients with advanced NSCLC before functional assessment has been integrated into the criteria. Background The change of tumour size is regarded as an objective indicator in assessing the efficiency of any anticancer therapy. Currently, the Response Evaluation Criteria in Solid Tumours (RECIST), which was established in * Correspondence: cmuliuyunpeng@yahoo.cn 1Department of Medical Oncology, The First Hospital, China Medical University, NO.155, North Nanjing Street, Heping District, Shenyang City, China Full list of author information is available at the end of the article 2000, and was revised in 2009, i.e. RECIST1.1, to replace the World Health Organization (WHO) criteria for tumour response evaluation, is widely used in evaluating the response to anticancer treatment. Using RECIST measurement criteria, patients in clinical treatments are stratified into one of four groups, i.e. complete response (CR), partial response (PR), stable disease (SD) and pro- gressive disease (PD) on the basis of change in lesion size [1] derived from CT scans. © 2010 He et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.