Hazard function analysis of prognosis after recurrent colorectal cancer

Abstract Background and objectives: Mean survival time (MST) is used as the indicator of prognosis in patients with a recurrence of colorectal cancer (CRC). Alternative to MST, we aimed to visualize the changes in death risk after a CRC recurrence using hazard function analysis (HFA). Methods: The medical records of 726 consecutive patients with a recurrence after R0 radical surgery for CRC were retrospectively reviewed. Results : The five-year survival rate post-recurrence was 37.7%, and the MST was 3.5 years, while the risk of death peaked at 2.90 years post-recurrence. Seven variables were found to predict short survival, including number of metastatic organs ≥ 2, non-surgical treatment for the recurrence, and a short interval before recurrence. In patients with a recurrence in one organ, the MST was four years, the peak time of death visualized by HFA was 2.9 years, and the five-year survival rate was 45.7%. In patients with surgical resection of the recurrence, the MST was 8 years, the peak time of death was 3.3 years, and the five-year survival rate was 61.8%. Conclusions : The present study established a novel method of assessing changes in mortality risk over time using HFA, in patients with a recurrence of colorectal cancer.