The cumulative burden of self-reported, clinically relevant outcomes in long-term childhood cancer survivors and implications for survivorship care: A DCCSS LATER study

BACKGROUND

The aim of this study is to evaluate how cumulative burden of clinically relevant, self-reported outcomes in childhood cancer survivors (CCSs) compares to a sibling control group and to explore how the burden corresponds to levels of care proposed by existing risk stratifications.

METHODS

The authors invited 5925 5-year survivors from the Dutch Childhood Cancer Survivor Study (DCCSS LATER) cohort and their 1066 siblings to complete a questionnaire on health outcomes. Health outcomes were validated by self-reported medication use or medical record review. Missing data on clinically relevant outcomes in CCSs for whom no questionnaire data were available were imputed with predictive mean matching. We calculated the mean cumulative count (MCC) for clinically relevant outcomes. Furthermore, we calculated 30-year MCC for groups of CCSs based on primary cancer diagnosis and treatment, ranked 30-year MCC, and compared the ranking to levels of care according to existing risk stratifications.

RESULTS

At median 18.5 years after 5-year survival, 46% of CCSs had at least one clinically relevant outcome. CCSs experienced 2.8 times more health conditions than siblings (30-year MCC = 0.79; 95% confidence interval [CI], 0.74-0.85 vs. 30-year MCC = 0.29; 95% CI, 0.25-0.34). CCSs' burden of clinically relevant outcomes consisted mainly of endocrine and vascular conditions and varied by primary cancer type. The ranking of the 30-year MCC often did not correspond with levels of care in existing risk stratifications.

CONCLUSIONS

CCSs experience a high cumulative burden of clinically relevant outcomes that was not completely reflected by current risk stratifications. Choices for survivorship care should extend beyond primary tumor and treatment parameters, and should consider also including CCSs' current morbidity.

Late Mortality in Childhood Cancer Survivors according to Pediatric Cancer Diagnosis and Treatment Era in the Dutch LATER Cohort

This multi-center cohort-study examined late mortality among 6,165 Dutch five-year childhood cancer survivors diagnosed 1963-2001. Clinical details and cause of death were based on medical records. Mortality was 12-fold that of the general population, with 51.3 additional deaths per 10,000 person-years (21.9 yrs median follow-up). Cumulative mortality 15 yrs post-diagnosis was 6.9%, predominantly from late recurrences; thereafter the absolute contribution of other health outcomes increased. Cumulative all-cause and recurrence-related mortality were highest for Central Nervous System and bone tumor survivors. All-cause, but not subsequent tumor and circulatory disease-related cumulative mortality, was highest for patients diagnosed 1963-1979 vs. later (p-trend <0.001).

Hematopoietic cell transplant in pediatric acute myeloid leukemia after similar upfront therapy; a comparison of conditioning regimens

The impact of conditioning regimen prior to hematopoietic cell transplant (HCT) in pediatric AML-patients is not well studied. We retrospectively analyzed the impact of Busulfan-Cyclophosphamide (BuCy), Busulfan-Cyclophosphamide-Melphalan (BuCyMel) and Clofarabine-Fludarabine-Busulfan (CloFluBu) in pediatric AML-patients, with similar upfront leukemia treatment (NOPHO-DBHconsortium), receiving an HCT between 2010 and 2015. Outcomes of interest were LFS, relapse, TRM and GvHD. 103 patients were included; 30 received BuCy, 37 BuCyMel, and 36 CloFluBu. The 5-years LFS was 43.3% (SE ± 9.0) in the BuCy group, 59.2 % (SE ± 8.1) after BuCyMel, and 66.7 % (SE ± 7.9) after CloFluBu. Multivariable Cox regression analysis showed a trend to lower LFS after BuCy compared to CloFluBu (p = 0.07). BuCy was associated with a higher relapse incidence compared to the other regimens (p = 0.06). Younger age was a predictor for relapse (p = 0.02). A strong correlation between Busulfan Therapeutic Drug Monitoring (TDM) and lower incidence of aGvHD (p < 0.001) was found. In conclusion, LFS after BuCyMel and CloFluBu was comparable, lower LFS was found after BuCy, due to higher relapse incidence. CloFluBu was associated with lower incidence of aGvHD, suggesting lower toxicity with this type of conditioning. This finding is also explained by the impact of Busulfan monitoring.

A detailed insight in the high risks of hospitalizations in long-term childhood cancer survivors-A Dutch LATER linkage study

Background

Insight in hospitalizations in long-term childhood cancer survivors (CCS) is useful to understand the impact of long-term morbidity. We aimed to investigate hospitalization rates and underlying types of diagnoses in CCS compared to matched controls, and to investigate the determinants.

Methods

We linked 5,650 five-year CCS from the Dutch nationwide Dutch LATER cohort and 109,605 age- and sex-matched controls to the Dutch Hospital Discharge register, which contained detailed information on inpatient hospitalizations from 1995–2016. Relative hospitalization rates (RHRs) were calculated using a Poisson regression model. Adjusting for multiple hospitalizations per person via a Poisson model for generalized estimated equations, we investigated determinants for hospitalizations for all types of underlying diagnoses among CCS.

Results

CCS were twice as likely to be hospitalized as reference persons (hospitalization rate 178 and 78 per 1,000 person-years respectively; RHR 2.0, 95% confidence interval (CI) 1.9–2.2). Although CCS had more hospitalizations for 17 types of underlying diagnoses, they were especially more likely to be hospitalized for endocrine conditions (RHR: 6.0, 95% CI 4.6–7.7), subsequent neoplasms (RHR: 5.6, 95% CI 4.6–6.7) and symptoms without underlying diagnoses (RHR: 5.2, 95% CI 4.6–5.8). For those types of underlying diagnoses, female sex and radiotherapy were determinants.

Conclusion

This study provides new insights in the high risk of hospitalizations for many types of underlying diagnoses in CCS and treatment related determinants. CCS are especially at high risk for hospitalizations for endocrine conditions, subsequent neoplasms and symptoms without an underlying diagnosis. This new knowledge is important for survivorship care and to identify possible preventable hospitalizations among CCS.

Validity of self-reported data on pregnancies for childhood cancer survivors: a comparison with data from a nationwide population-based registry

STUDY QUESTION

To what degree do records registered in the Netherlands Perinatal Registry (PRN) agree with self-report in a study questionnaire on pregnancy outcomes in childhood cancer survivors (CCSs)?

SUMMARY ANSWER

This study suggests that self-reported pregnancy outcomes of CCSs agree well with registry data and that outcomes reported by CCSs agree better with registry data than do those of controls.

WHAT IS KNOWN ALREADY

Many studies have shown that childhood cancer treatment may affect fertility outcomes in female CCSs; however, these conclusions were often based on questionnaire data, and it remains unclear whether self-report agrees well with more objective sources of information.

STUDY DESIGN, SIZE, DURATION

In an nationwide cohort study on fertility (inclusion period January 2008 and April 2011, trial number: NTR2922), 1420 CCSs and 354 sibling controls were invited to complete a questionnaire regarding socio-demographic characteristics and reproductive history. In total, 879 CCSs (62%) and 287 controls (81%) returned the questionnaire.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The current validation study compared the agreement between pregnancy outcomes as registered in the PRN and self-reported outcomes in the study questionnaire. A total of 589 pregnancies were reported in CCSs, and 300 pregnancies in sibling controls, of which 524 could be linked to the PRN.

MAIN RESULTS AND THE ROLE OF CHANCE

A high intra-class correlation coefficient (ICC) was found for birthweight (BW) (0.94 and 0.87 for CCSs and controls, respectively). The self-reported BWs tended to be higher than reported in the PRN. For gestational age (GA), the ICC was high for CCSs (0.88), but moderate for controls (0.49). CCSs overestimated GA more often than controls. The Kappa values for method of conception and for method of delivery were moderate to good. Multilevel analyses on the mean difference with regard to BW and GA showed no differences associated with time since pregnancy or educational level.

LIMITATIONS, REASONS FOR CAUTION

Not all pregnancies reported could be linked to the registry data. In addition, the completeness of the PRN could not be assessed precisely, because there is no information on the number of missing records. Finally, for some outcomes there were high proportions of missing values in the PRN registry.

WIDER IMPLICATIONS OF THE FINDINGS

Our study suggests that questionnaires are a reliable method of data collection, and that for most variables, self-report agrees well with registry data.

STUDY FUNDING/COMPETING INTEREST

This work was supported by the Dutch Cancer Society (grant no. VU 2006-3622) and by Foundation Children Cancer Free. None of the authors report a conflict of interest.

TRIAL REGISTRATION NUMBER

NTR2922 http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=2922.