Decreasing Late Mortality Among Five-Year Survivors of Cancer in Childhood and Adolescence: A Population-Based Study in the Nordic Countries

Abstract

PURPOSE: To assess the risk of death in patients who survive more than 5 years after diagnosis of childhood cancer and to evaluate causes of death in fatal cases. PATIENTS AND METHODS: This was a population-based study in the five Nordic countries (Denmark, Finland, Iceland, Norway, and Sweden) using data of the nationwide cancer registries and the cause-of-death registries. The study cohort included 13,711 patients who were diagnosed with cancer before the age of 20 years between 1960 and 1989 and who survived at least 5 years from diagnosis. By December 31, 1995, 1,422 patients had died, and death certificates were assessed in 1,402. Standardized mortality ratios (SMRs) for validated causes of death were calculated based on 156,046 patient-years at risk. RESULTS: The overall SMR was 10.8 (95% confidence interval [CI], 10.3 to 11.5), mainly due to high excess mortality from the primary cancer. SMR for second cancer was 4.9 (95% CI, 3.9 to 5.9) and was 3.1 (95% CI, 2.8 to 3.5) for noncancer death. The pattern of causes of death varied markedly between different groups of primary cancer diagnoses and was highly dependent on time passed since diagnosis. Overall late mortality was significantly lower in patients treated during the most recent period of time, 1980 to 1989, compared with those treated from 1960 to 1979 (hazard ratio, 0.61; 95% CI, 0.54 to 0.70), and there was no increase in rates of death due to cancer treatment. CONCLUSION: Long-term survivors of childhood cancer had an increased mortality rate, mainly dying from primary cancers. However, modern treatments have reduced late cancer mortality without increasing the rate of therapy-related deaths.

Late mortality among 5‐year survivors of early onset cancer: A population‐based register study

“…The overall mortality rate of childhood cancer survivors was somewhat lower in our study (SMR 7.6) than in previous childhood cancer studies with a spectrum from SMR 8.4 to 10.8. 4,6,8,9 Moreover, our slightly lower overall SMR of 4.2 in young adult cancer survivors resembled earlier results, which were between 4.6 and 5.9. 10,11 The somewhat lower figures in our study may result from including the most recent treatment periods with possibly improved therapy regimens and from the effect of older attained age due to our very long follow-up.…”

“…[1][2][3] Thus far the main focus of late effect research has been on the morbidity and mortality of childhood cancer survivors aged up to 21 years at cancer diagnosis. [4][5][6][7][8][9] Only few studies have investigated those topics for the survivors of young adult (YA) cancer patients aged from 20 to 34 years at cancer diagnosis. [10][11][12] Previous studies have found elevated risks for chronic health conditions which contribute to higher mortality among survivors of childhood cancer patients compared to the general population.…”

“…[10][11][12] Previous studies have found elevated risks for chronic health conditions which contribute to higher mortality among survivors of childhood cancer patients compared to the general population. 5,9,13,14 Patterns of increased excess mortality after childhood cancer have been shown to be dependent on time from cancer diagnosis and cause of death. 4,7,11 The success of improved cancer survival is overshadowed by the life-threatening chronic health outcomes that cancer survivors are more likely to suffer from.…”

Up-to-date survival curves of children with cancer by period analysis

“…In fact, this theoretical possibility has been repeatedly forwarded as a caveat against the use of period analysis, and it has been suggested to be of particular concern for childhood cancers, as a consequence of possible late adverse treatment effects. However, studies have shown that modern treatment of childhood cancers tended to reduce rather than increase occurrence of late cancer deaths (in addition to reducing occurrence of early cancer deaths) (Robertson et al, 1994;Hudson et al, 1997;Möller et al, 2001). In agreement with these findings, our empirical evaluation suggests that the theoretical possibility of overoptimistic survival estimates by period analysis appears to be as irrelevant in practice as it is for adulthood cancers (Brenner and Hakulinen, 2002a, b, c;.…”

“…Gatta et al, 2002). Although most deaths among children with cancer occur during the first 5 years following diagnosis, the proportion of late deaths occurring beyond the fifth year following diagnosis is not negligible for many forms of childhood cancers (Mertens et al, 2001;Möller et al, 2001). Therefore, more long-term survival statistics are of particular interest for childhood cancer.…”