Respiratory mortality of childhood, adolescent and young adult cancer survivors

Abstract

Background: Exposure to radiation and/or chemotherapy during cancer treatment can compromise respiratory function. We investigated the risk of long-term respiratory mortality among 5-year cancer survivors diagnosed before age 40 years using the British Childhood Cancer Survivor Study (BCCSS) and Teenage and Young Adult Cancer Survivor Study (TYACSS).

Methods: The BCCSS comprises 34 489 cancer survivors diagnosed before 15 years from 1940 to 2006 in Great Britain. The TYACSS includes 200 945 cancer survivors diagnosed between 15 years and 39 years from 1971 to 2006 in England and Wales. Standardised mortality ratios and absolute excess risks were used.

Findings: Overall, 164 and 1079 respiratory deaths were observed in the BCCSS and TYACSS cohorts respectively, which was 6.8 (95% CI 5.8 to 7.9) and 1.7 (95% CI 1.6 to 1.8) times that expected, but the risks varied substantially by type of respiratory death. Greatest excess numbers of deaths were experienced after central nervous system (CNS) tumours in the BCCSS and after lung cancer, leukaemia, head and neck cancer and CNS tumours in the TYACSS. The excess number of respiratory deaths increased with increasing attained age, with seven (95% CI 2.4 to 11.3) excess deaths observed among those aged 50+ years in the BCCSS and three (95% CI 1.4 to 4.2) excess deaths observed among those aged 60+ years in the TYACSS. It was reassuring to see a decline in the excess number of respiratory deaths among those diagnosed more recently in both cohorts.

Conclusions: Prior to this study, there was almost nothing known about the risks of respiratory death after cancer diagnosed in young adulthood, and this study addresses this gap. These new findings will be useful for both survivors and those involved in their clinical management and follow-up.

Keywords: clinical epidemiology; copd epidemiology; paediatric interstitial lung disease; pneumonia.

Figure 1

SMRs and AERs per 10 000 person-years for all respiratory mortality in the British Childhood Cancer Survivor Study. P heterogeneity and p trend were calculated by using likelihood ratio tests within multivariable Poisson regression models that adjusted for sex, first primary neoplasm type, age at diagnosis, treatment era and attained age. Strata with less than five observed events should be interpreted with caution. AER, absolute excess risk; AML, acute myeloid leukaemia; CNS, central nervous system; E, expected; O, observed; PNETs, primitive neuroectodermal tumour; SMR, standardised mortality ratio.

Figure 2

SMRs and AERs per 10 000 person-years for pneumonia mortality in the British Childhood Cancer Survivor Study. P heterogeneity and p trend were calculated by using likelihood ratio tests within multivariable Poisson regression models that adjusted for sex, first primary neoplasm type, age at diagnosis, treatment era and attained age. Strata with less than five observed events should be interpreted with caution. AER, absolute excess risk; AML, acute myeloid leukaemia; CNS, central nervous system; E, expected; O, observed; PNETs, primitive neuroectodermal tumours; SMR, standardised mortality ratio.

Figure 3

SMRs and AERs per 10 000 person-years for all respiratory mortality in the Teenage and Young Adult Cancer Survivor Study. P heterogeneity and p trend were calculated by using likelihood ratio tests within multivariable Poisson regression models that adjusted for sex, first primary neoplasm type, age at diagnosis, treatment era and attained age. Strata with less than five observed events should be interpreted with caution. AER, absolute excess risk; AML, acute myeloid leukaemia; CNS, central nervous system; E, expected; O, observed; PNETs, primitive neuroectodermal tumour; SMR, standardised mortality ratio.

Figure 4

SMRs and AERs per 10 000 person-years for pneumonia mortality in the Teenage and Young Adult Cancer Survivor Study. P heterogeneity and p trend were calculated by using likelihood ratio tests within multivariable Poisson regression models that adjusted for sex, first primary neoplasm type, age at diagnosis, treatment era and attained age. Strata with less than five observed events should be interpreted with caution. AER, absolute excess risk; AML, acute myeloid leukaemia; CNS, central nervous system; E, expected; O, observed; PNETs, primitive neuroectodermal tumour; SMR, standardised mortality ratio