This dissertation, "Cancer Staging for Differentiated Thyroid Carcinoma" by Brian, Lang, 梁熊顯, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author.
Abstract:
ABSTRACT of thesis entitled "Cancer staging for differentiated thyroid carcinoma" Submitted by Dr. Brian Lang For the degree of Master of Surgery At the University of Hong Kong in June 2006
Thyroid carcinoma is the commonest endocrine malignancy with a progressively increasing incidence worldwide. A predictive staging system for thyroid carcinoma not only provides important prognostic information to clinicians and their patients but also facilitates management and standardizes information exchange between medical centers for research purpose. A systematic review of MEDLINE search from 1965 to 2005 identified 17 different staging systems applicable to differentiated thyroid carcinoma (DTC) in the English literature, the majority of which were derived from and applied to Anglo-American or European patients.
Independent prognostic factors for papillary (PTC, n=589) and follicular thyroid carcinoma (FTC, n=171) were separately identified first by univariate and multivariate th th analyses. To decide whether the AJCC/UICC 5 or 6 edition TNM should be included in the subsequent analysis, their relative predictability for cancer-specific survival (CSS) was compared. This was followed by assessment of the overall performance of the 17 staging systems. Predictability was first evaluated by calculating the proportion of variance explained (PVE) for each system in 760 DTC managed from 1961-2001 at Queen Mary Hospital. This was followed by an evaluation of practicality and reproducibility. These qualities were assessed by applying these 17 staging systems simultaneously to two separate patient cohorts, one from Queen Mary Hospital (n=760) and the other from Queen Elizabeth Hospital thyroid cancer databases (n=1199), both of
iiwhich are tertiary referral centers in Hong Kong. Their stage-specific CSS and relative ranking of these staging systems were compared.
Although age >= 50 years and incomplete resection were independent prognostic factors common to both PTC and FTC, tumor size, extrathyroidal extension and distant th metastases were specific only to either histologic type. The AJCC/UICC 6 edition TNM th appeared to have a better predictability than the 5 edition TNM. Among the 17 staging systems, as measured by the PVE value, the MACIS was the most predictive system in th PTC whereas the 6 edition TNM was the most predictive system in FTC at the Queen Mary Hospital. These top rankings were also observed when these systems were applied to the other patient cohort at the Queen Elizabeth Hospital. However, the CSS of MACIS risk group II in PTC at Queen Mary Hospital differed significantly from that of MACIS th risk group II at Queen Elizabeth Hospital (p
Although the MACIS had the highest PVE values in both hospitals for PTC, it could th not reproduce similar stage-specific CSS in all risk groups like in the 6 edition TNM. th For FTC, the 6 TNM system remained the best system in both hospitals.
th The AJCC/UICC 6 edition TNM system is the most predictive, practical and reproducible staging system for the two histologic types in Hong Kong and therefore, this system should be the staging system of choice for future prognostication and cancer information exchange between centers in Hong Kong.
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DOI: 10.5353/th