Simplifying the TNM system for clinical use in differentiated thyroid cancer.
ABSTRACT The TNM stratification has been found useful at stratifying patients with differentiated thyroid carcinoma (DTC) into prognostic risk groups. However, it is cumbersome to implement clinically given the large number of bins within this system and the complicated system of arriving at stage information.
We decided to quantify each variable in this system to arrive at a simplified quantitative alternative to the TNM system (QTNM) and compare this with the conventional system. We used our electronic record system to identify 614 cases of DTC managed at our institution from 1987 to 2006. Cancer-specific survival (CSS) and disease-free survival (DFS) were calculated by the Kaplan-Meier method, and a simplified QTNM score was devised using a Cox proportional hazards model.
We were able to quantify the TNM system as follows: 4 points each for age older than 45 years and presence of neck nodal metastases while 6 points for tumor size larger than 4 cm or extrathyroidal extension and 1 point for nonpapillary DTC. A sum of 0 to 5 points was low risk, 6 to 10 points intermediate, and 11 to 15 points high risk. Comparison with the conventional TNM system and two other systems revealed similar or better discrimination with the QTNM and this discrimination was maintained when this risk stratification was applied to a unique validation set.
The QTNM system as opposed to the conventional TNM system seems to be a simple and effective method for risk stratification for both recurrence and cancer-specific mortality.
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ABSTRACT: To determine the effect of the extent of thyroidectomy and additional postsurgical radioiodine remnant ablation (RRA) on the survival of patients with differentiated thyroid carcinoma (DTC) after adjustment for risk stage. We electronically identified 614 cases of DTC at our institution between 1987 and 2006. Two treatment variables were created, surgical extent dichotomized to total versus other and a composite of surgery and radioactive iodine ablation. The odds of cancer specific survival and disease-free survival (DFS) were determined using Cox proportional hazards model with adjustment for quantitative tumor-node-metastasis risk score. Of 614 patients with DTC during our period, 504 (83%) underwent total thyroidectomy and 104 (17%) underwent lesser surgery. Radioiodine administration was reported for 394 patients who underwent total thyroidectomy with a dose range of 24 to 297 mCi (mean of 116 mCi). Ten-year survival was higher for patients with total thyroidectomy compared with lobectomy: 96% versus 84% (P<0.001, Gehan's Wilcoxon test). Ten-year survival for complete versus incomplete surgery for tumor stages 1 and 2 was 99% versus 96%, and for stages 3 and 4 was 88% versus 52%. Cancer specific death tended to occur earlier in those without RRA postsurgery. There was no overall relationship between DFS and RRA or surgery, but in the higher risk categories surgery retained significance. Our data support the routine use of both total or near-total thyroidectomy followed by RRA over all risk categories in DTC. Although the effect of surgery is clear, there is also a trend toward improvement in outcome with RRA for cancer specific survival.Clinical nuclear medicine 06/2010; 35(6):396-9. · 3.92 Impact Factor
- Nature Reviews Endocrinology 10/2009; 5(10):531-2. · 11.03 Impact Factor
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ABSTRACT: Context: The utility of preablation radioiodine scans for the management of differentiated thyroid cancer remains controversial. Objective: To determine the contribution of preablation Iodine 131 (131-I) planar with single-photon emission computed tomography/computed tomography (SPECT/CT; diagnostic [Dx] scans) to differentiated thyroid cancer staging. Design: Prospective sequential series at university clinic. Methods: Using American Joint Committee on Cancer (AJCC) tumor, node, metastasis (TNM) staging, seventh edition 320 patients post-total thyroidectomy were initially staged based on clinical and pathology data (pTN) and then restaged after imaging (TNM). The impact of Dx scans with SPECT/CT on N and M scores, and TNM stage, was assessed in younger, age <45 years, n = 138 (43%), and older, age ≥45 years, n = 182 (57%) patients, with subgroup analysis for T1a and T1b tumors. Results: In younger patients Dx scans detected distant metastases in 5 of 138 patients (4%), and nodal metastases in 61 of 138 patients (44%), including unsuspected nodal metastases in 24 of 63 (38%) patients initially assigned pathologic (p) N0 or pNx. In older patients distant metastases were detected in 18 of 182 patients (10%), and nodal metastases in 51 of 182 patients (28%), including unsuspected nodal metastases in 26 of 108 (24%) patients initially assigned pN0 or pNx. Dx scans detected distant metastases in 2 of 49 (4%) T1a, and 3 of 67 (4.5%) T1b patients. Conclusions: Dx scans detected regional metastases in 35% of patients, and distant metastases in 8% of patients. Information acquired with Dx scans changed staging in 4% of younger, and 25% of older patients. Preablation scans with SPECT/CT contribute to staging of thyroid cancer. Identification of regional and distant metastases prior to radioiodine therapy has significant potential to alter patient management.The Journal of clinical endocrinology and metabolism 03/2013; 98(3):1163-71. · 6.50 Impact Factor