Long-term survival in Hodgkin's disease patients: a comparison of relative survival in patients in trials and those recorded in population-based cancer registries
Introduction
The prognosis of Hodgkin's disease (HD) has greatly improved during the last 30 years, and as a consequence it has become important to determine the extent of long-term survival, and whether after several years survival, mortality approximates that of the general population. Crude survival analysis 1, 2, as frequently used in the analysis of trials, gives only partial information because, especially as the patients grow older, some deaths would be expected if the patients simply suffered general population mortality rates (i.e. if they ceased to suffer adverse mortality as a consequence of their past Hodgkin's disease). Adjustment for competing causes of death is then necessary if one wants to analyse the late effects of treatment on survival.
Survival is most often estimated from clinical series, but such series are selected to meet entry criteria for the trials and also may be unrepresentative of general population survival because they may receive better care within the trials. At a public health level, it would be interesting to know how survival rates obtained from clinical trial series compare with survival rates from population-based data, and hence the extent to which trial results may imply prognosis for patients generally. Although studies comparing the prognosis of patients included in clinical trials with those not included have been published for several sites [3], there appear to have been no studies for Hodgkin's disease.
To address these questions, we analysed survival in patients participating in the randomised clinical trials of the British National Lymphoma Investigation (BNLI) 4, 5 between 1970 and 1987, and compared their long-term relative survival 6, 7 with that in population-based UK data [8].
Section snippets
BNLI data
The BNLI is a large British clinical collaborative group which since 1970 has conducted clinical trials of treatment of lymphoma. Approximately two-thirds of patients at the collaborating centres are entered into the trials, a greater proportion at younger than at older adult ages. The present analyses were conducted on the records of 2755 HD patients aged 15–79 years, all of the subjects included in BNLI trials between 1970 and 1987. Demographic, clinical, and biological variables were
Distribution of cases by age
Fig. 1 shows the distribution by age of the BNLI cases (median=32 years; 15–79) and population-based cases (median=41 years; 15–79). The median values of age in the four age groups (15–24; 25–44; 45–64; 65–79) were respectively 20, 32, 54 and 69 years for BNLI patients and 20, 33, 56 and 71 years for population-based cases.
Long-term survival and net annual mortality
To follow current practice in the analysis of Hodgkin's disease data [15], results were presented distinguishing BNLI early stages (CS I and CS II) and advanced stages (CS
Discussion
An excess of mortality compared with that in the general population was still observed up to 15 years after diagnosis for advanced stage HD, and a smaller excess was also observed for early stage HD. HD incidence is higher in populations with elevated social status, who have a higher life expectancy than the general population. The use of general population mortality tables for comparison will, therefore, have tended to lead to overestimation of the relative survival rates of the patients. A
Acknowledgements
The authors acknowledge a referee for helpful comment for comparison of the two datasets.
References (23)
- et al.
Review of British National Lymphoma Investigation studies of Hodgkin's disease and development of prognostic index
Lancet
(1985) - et al.
Diagnosis and grading of nodular sclerosing Hodgkin's diseasea study of 2190 patients
Int. Rev. Exp. Pathol.
(1992) - et al.
The prognostic significance of age in Hodgkin's diseaseexamination of 1500 patients (BNLI report No. 23)
Clin. Radiol.
(1983) - et al.
The prognostic significance of age in patients with advanced Hodgkin's disease
Eur. J. Cancer
(1988) - et al.
Non-parametric estimation from incomplete observations
J. Am. Stat. Assoc.
(1958) Regression models and life-tables
J. R. Statist. Soc. series B
(1972)Centralised treatment, entry to trials and survival
Br. J. Cancer
(1994)- MacLennan KA, Bennett MH, Bosq J, et al. The histology and immunohistology of Hodgkin's disease: its relationship to...
- et al.
The relative survival ratea statistical methodology
Nat Cancer Inst Monographs
(1961) - et al.
Relative survival and the estimation of net survivalelements for further discussion
Stat. Med.
(1990)
Survival of cancer patients in Europe. The Eurocare study
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