Non-cancer mortality among long-term survivors of adult cancer in Korea: national cancer registry study

To investigate the pattern of non-cancer deaths and to determine whether there is excess mortality from non-cancer causes among Korean long-term survivors of adult cancer. We merged national cancer registry data and national death registration data to determine non-cancer death patterns of 243,713 people who were diagnosed with cancer from 1993 to 2000 and who survived a parts per thousand yen5 years. We calculated standardized mortality ratios (SMRs) by an indirect standardization method. Of the patient population, 26,498 (10.9%) had died as of December 2005; the cause of death for 6,364 (24.0%) of those was not cancer. The proportion of non-cancer mortality increased with age at diagnosis and correlated with the 5-year survival rate (r = 0.336 for women, 0.571 for men). Although the risk for non-cancer death was lower among long-term survivors in general (SMR, 0.78; 95% CI, 0.76-0.80), it was higher among younger survivors (SMR, 1.23-2.50, for those who died before 50) than the general population. Survivors had an elevated suicide rate (SMR, 1.28; 95% CI, 1.15-1.42), especially male (SMR, 1.35; 95% CI, 1.19-1.53) and stomach cancer survivors (SMR, 1.38; 95% CI, 1.14-1.66). Appropriate medical attention for long-term adult cancer survivors, especially younger survivors, is warranted to prevent premature deaths from non-cancer causes.