What is the fine-grained topic of the following text: In an intention-to-treat population of 59 of these patients with an autologous stem cell transplant to consolidate response, the median OS differed again across the high-, intermediate-, and low-risk groups at 1.4 years, 5.9 years, and not reached, respectively (P <.001). Only return the topic.
Autologous stem cell transplant outcomes in different risk groups