Biomedical subjects
Publications and source records attributed to A Laplanche.
The direct method and life-table methods (actuarial and Kaplan-Meier) for estimating survival rates are described here. The difference between direct method and lifetable method is the use of information about the patients who are still alive. Practical examples of calculation are given with recommandations for graphical displays.
It is standard practice in epidemiological studies to compare the observed mortality of a cohort to the mortality expected in a reference population of the same age and sex distributions computed from national statistics. The same methods can be used in a prognostic study where the effects on survival of potential prognostic factors are studied in a cohort of patients with a given disease. Writing the hazard function in the cohort as the product of the hazard function in the reference population and a function of some characteristics of the patients, one can derive simple estimates and statistical tests of the standardised mortality ratios (Breslow et al.). The study of a cohort of patients with thyroid cancer will provide an example.
BACKGROUND/AIMS: The aims of this study were to assess response rates, evaluate side effects and determine prognostic factors for both response and toxicity in patients with liver metastasis from endocrine tumors treated with chemoembolization. METHODOLOGY: Data concerning 64 patients who underwent a total of 186 sessions of chemoembolization were retrospectively evaluated and correlated with response and toxicity after chemoembolization. RESULTS: Overall clinical, morphological and biological response rates were 93%, 74% and 52% respectively. Complete control of hormone-related symptoms was obtained in 59% of patients with a mean duration of response of 15 months. Transient major complications occurred after 5.9% of sessions and 3 patients died. In the univariate and multivariate analyses, a non-pancreatic primary and chemoembolization as first-line non-surgical treatment were prognostic factors for clinical response, and <30% of liver involvement for morphological response. A significant increase in morbidity was noted in patients with more than 70% of liver involvement. CONCLUSIONS: Hormone-related symptoms were controlled in the majority of patients with a non-pancreatic primary and in those treated with chemoembolization as first-line therapy. Morphological response and toxicity were respectively correlated with liver involvement of less than 30% and greater than 70%.