PATHOLOGY & ONCOLOGY RESEARCHVol. 8 No. 2, 2002

 Article

Markov Model-based Estimation of Individual Survival Probability for Medullary Thyroid Cancer Patients

Olga ÉSIK1, Gábor TUSNÁDY3, Lajos TRÓN4, András BOÉR5, Zoltán SZENTIRMAY6, István SZABOLCS7, Károly RÁCZ8, Erzsébet LENGYEL2, Judit SZÉKELY2, Miklós KÁSLER5

1Department of Oncotherapy, Semmelweis University, Budapest, Hungary
2Department of Radiotherapy, National Institute of Oncology, Budapest, Hungary
3Rényi Alfréd Mathematical Institute, Hungarian Academy of Sciences, Budapest, Hungary
4PET Centre, University of Debrecen, Debrecen, Hungary
5Department of Head and Neck Surgery, National Institute of Oncology, Budapest, Hungary
6Department of Molecular Pathology, National Institute of Oncology, Budapest, Hungary
7Department of Endocrinology, National Health Centre, Budapest, Hungary
82nd Department of Medicine, Semmelweis University, Budapest, Hungary

 

The relatively benign, but occasionally rapidly fatal clinical course of medullary thyroid cancer (MTC) has raised the need for individual survival probability estimation. A retrospective study on 91 MTC clinical case histories with a mean follow-up of 6 years indicated prevalences of local, regional and distant residual tumor on primary care completion of 23%, 54% and 54%, respectively. Local, regional and distant relapses during follow-up occurred in 8%, 23% and 26% of the patients, with a cause-specific death in 26% of the cases. Prognostic factors statistically significantly influencing the cause-specific survival were selected by uni- and multivariate analysis. A Markov method-based model was developed for the estimation of individual time-dependent local, regional and distant relapse-free and cause-specific survival probability functions, with parameters numerically determined via a maximum likelihood procedure. These parameters include relative risk factors related to prognosticators, a residual or recurrent local/regional/distant tumor, and combinations of these entities. In multivariate studies, the patient’s age and gender, the genetic basis of the dis-ease, lymph node involvement, the existence of a general symptom (diarrhoea) at presentation, and the dosage of external irradiation proved to be prognosticators. The cause-specific survival function of the study population indicated mean 5, 10 and 15-year survival probabilities of 69%, 62% and 58%. CONCLUSION: Survival probabilities can be predicted for extrastudy cases provided that the same laws and principles govern the clinical course of these cases and those comprising the study. For individual survival probability estimation, a Pascal program (MEDUPRED) was written and is available on the home page of the National Institute of Oncology, Budapest (www.oncol.hu). Pathology & Oncology Research, Vol 8, Nr 2, 93-104, 2002

Key words: medullary thyroid carcinoma; prognosis; multivariate analysis; Markov model; individual survival probability; MEDUPRED


Received: May 27, 2002; accepted: Jun 20, 2002
Correspondence: Olga ÉSIK, Department of Radiotherapy, National Institute of Oncology, Budapest H-1122, Hungary; Tel: 36-1-1-2248689, Fax: 36-1-2248620; E-mail: esik@oncol.hu

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