Minimum follow-up time required for the estimation of statistical cure of cancer patients: verification using data from 42 cancer sites in the SEER databaseReportar como inadecuado




Minimum follow-up time required for the estimation of statistical cure of cancer patients: verification using data from 42 cancer sites in the SEER database - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

BMC Cancer

, 5:48

First Online: 17 May 2005Received: 18 October 2004Accepted: 17 May 2005DOI: 10.1186-1471-2407-5-48

Cite this article as: Tai, P., Yu, E., Cserni, G. et al. BMC Cancer 2005 5: 48. doi:10.1186-1471-2407-5-48

Abstract

BackgroundThe present commonly used five-year survival rates are not adequate to represent the statistical cure. In the present study, we established the minimum number of years required for follow-up to estimate statistical cure rate, by using a lognormal distribution of the survival time of those who died of their cancer. We introduced the term, threshold year, the follow-up time for patients dying from the specific cancer covers most of the survival data, leaving less than 2.25% uncovered. This is close enough to cure from that specific cancer.

MethodsData from the Surveillance, Epidemiology and End Results SEER database were tested if the survival times of cancer patients who died of their disease followed the lognormal distribution using a minimum chi-square method. Patients diagnosed from 1973–1992 in the registries of Connecticut and Detroit were chosen so that a maximum of 27 years was allowed for follow-up to 1999. A total of 49 specific organ sites were tested. The parameters of those lognormal distributions were found for each cancer site. The cancer-specific survival rates at the threshold years were compared with the longest available Kaplan-Meier survival estimates.

ResultsThe characteristics of the cancer-specific survival times of cancer patients who died of their disease from 42 cancer sites out of 49 sites were verified to follow different lognormal distributions. The threshold years validated for statistical cure varied for different cancer sites, from 2.6 years for pancreas cancer to 25.2 years for cancer of salivary gland. At the threshold year, the statistical cure rates estimated for 40 cancer sites were found to match the actuarial long-term survival rates estimated by the Kaplan-Meier method within six percentage points. For two cancer sites: breast and thyroid, the threshold years were so long that the cancer-specific survival rates could yet not be obtained because the SEER data do not provide sufficiently long follow-up.

ConclusionThe present study suggests a certain threshold year is required to wait before the statistical cure rate can be estimated for each cancer site. For some cancers, such as breast and thyroid, the 5- or 10-year survival rates inadequately reflect statistical cure rates, and highlight the need for long-term follow-up of these patients.

Electronic supplementary materialThe online version of this article doi:10.1186-1471-2407-5-48 contains supplementary material, which is available to authorized users.





Autor: Patricia Tai - Edward Yu - Gábor Cserni - Georges Vlastos - Melanie Royce - Ian Kunkler - Vincent Vinh-Hung

Fuente: https://link.springer.com/



DESCARGAR PDF




Documentos relacionados