1. ¹Department of Hematology/Oncology, Kyungpook National University Hospital, Daegu, Korea
2. ²Department of Hematology, University of Ulsan, Asan Medical Center, Seoul, Korea
3. ³Department of Biostatistics, Taegu Catholic University, School of Medicine, Daegu, Korea
4. ⁴Department of Hematology/Oncology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
5. ⁵Department of Hematology/Oncology, Ulsan University Hospital, University of Ulsan, Ulsan, Korea

Correspondence: Dr DH Kim, Department of Hematology/Oncology, Samsung Medical Center, Ilwon-dong 50, Kangnam-gu, Seoul 135-710, Republic of Korea. E-mail: drkiim@medimail.co.kr

Received 6 November 2006; Revised 25 June 2007; Accepted 2 July 2007; Published online 13 August 2007.

Abstract

GVHD-specific survival (GSS) has been investigated as a potential study end point to describe the clinical course and outcome of chronic GVHD (cGVHD). However, reaching this end point requires a long observation time. We hypothesized that the time to the first flare-up (FFU) of cGVHD (TTF) can be an alternative statistical end point to GSS. This retrospective study included 96 patients with a diagnosis of cGVHD from a cohort of 119 patients with a prior history of acute GVHD. The median TTF was 73 days after the diagnosis of cGVHD. The 2-year cumulative incidences of first, second and third episodes of flare-up (FU) during courses of cGVHD were estimated as 69.5, 46.4 and 22.1%. Those patients who did not have an episode of FU of cGVHD had 96.0% of 2-years GSS rate, while those with 1 and 2 episodes had 50.8 and 46.8%, respectively (P=0.001). Shorter TTF was associated with poor GSS and decreased overall survival. The shorter TTF during the course of cGVHD was significantly associated with extensive cGVHD (P=0.002), Hopkins' risk category (P=0.022) and progressive-type cGVHD (P<0.001) in multivariate analysis. We propose that TTF can be an alternative end point to GSS in cGVHD trials.