Survival prediction in terminal cancer patients: a systematic review of the medical literature

Abstract

The clinical significance of studies on survival predictors in terminal cancer patients is hindered by both methodological limitations and the difficulty of finding common predictors for all final events in cancer related deaths. To evaluate the published medical literature concerned with the survival of patients with terminal cancer and identify potential prognostic factors, major electronic databases including MEDLINE (1966-), CANCERLIT (1983-) and EMBASE (1988-) were searched up to September 1999. Studies were included in our review if published in English, were cohort studies, addressed the identification of clinical prognostic factors for survival and looked at samples with median survival of < or = 3 months. Data extracted from selected papers included: sample size, median survival, type of study, sampling frame, cohort type, type of statistical analysis (univariate or multivariate), choice of models and underlying assumptions, predictors examined and their reported level of statistical significance. A total of 24 studies were found and reviewed. On the basis of these studies, performance status and the presence of cognitive failure, weight loss, dysphagia, anorexia and dyspnoea appear to be independent survival predictors in this population. Clinical estimation of survival by the treating physician appeared independently associated with survival but the magnitude of the association generally appeared small. Clinical predictions should be considered as one of many criteria, rather than as a unique criterion by which to choose therapeutic interventions or health care programmes for terminally ill cancer patients. The use of convenient samples as opposed to more representative inception cohorts, the inclusion of different variables in the statistical analyses and inappropriate statistical methods appear to be major limitations of the reviewed literature. Methodological improvements in the design and conduction of future studies may reduce the prognostic uncertainty in this population.

Quality of life and survival prediction in terminal cancer patients

“…22 Some authors have found that the presence or intensity of some physical symptoms (e.g., cognitive impairment, anorexia, xerostomia, dysphagia, and dyspnea) have independent prognostic importance in patients with a median survival of Ͻ 2 months. 23 Others have argued, however, that psychosocial measurements have dubious predictive value 24 -28 and that HRQoL measures (e.g., the Spitzer Quality of Life Index) cannot be used on their own to establish a prognosis in individual patients. 29 It is possible the validity and generalizability of these discrepant results may have been affected by methodological issues, such as a lack of precise criteria to define the onset of the terminal phase, difficulty in recruiting representative cohorts among patients with advanced or terminal cancer, and missing potential prognostic factors in the design of the study.…”

“…26 -28,33,34 In addition, the prognostic factors considered often differ across studies, preventing possible evaluation of effects found by individual studies on these domains. 23 The current study was designed to overcome these limitations and to determine whether patient-rated and staff-rated QoL measurements in patients with cancer, who were seen at two different stages of their terminal phase, could be combined with medical data to predict survival.…”

The relationship between the insulin-like growth factor-1 axis, weight loss, an inflammation-based score and survival in patients with inoperable non-small cell lung cancer

“…Grouping of the variables age, BMI, ECOG-ps, haemoglobin and white cell count was carried out using standard thresholds [22][23][24] . Survival analysis of the variables was performed using the Cox proportional hazard model.…”

Assisted death: a basic right or a threat to the principal purpose of medicine?

“…The churches are opposed, although 78% of people of faith are in favour. 6 Those with disabilities are in favour (75%), while their representative organisations are against. 7 The medical bodies are mostly opposed, although more than two-thirds of GPs believe that the Royal College of General Practitioners should change its stance on the issue, subject to a number of safeguards.…”

“…[6][7][8] Some patients even improve from a seemingly hopeless situation to resume an active and fulfilling existence. Oregon's own data since 1997 show a mean of 47 days from request to death by legalised PAS, with a range of 15 to 1,009 days, 9 despite the requirement of a prognosis of six months or less.…”