A comparison of different staging systems predictability of patient outcome

[Thyroid cancer: prognostic factors and treatment]

Because most differentiated thyroid carcinomas have an excellent prognosis, some authors have claimed that these patients are suffering from over treatment. Grouping patient- and tumor-specific factors have been proposed for prognostic stratification, but no clinicopathologic staging was demonstrated to be useful at the present time. More recently, molecular genetic tools have been used to identify and understand how the primary tumor progresses and many molecular markers have been proposed in order to distinguish the subset of patients at risk of developing metastasis. Here we analyzed some of them, with emphasis on the expression of NIS, a determinant of prognosis since the functional integrity of the iodine transport is essential to assure an uptake of radioiodine high enough to detect and destroy any tumoral thyroid tissue. More recent observations on how some relevant molecular genetics aspects of thyroid cancer impact new potential therapeutic approaches are also discussed.

Implications of mediastinal uptake of131I with regard to surgery in patients with differentiated thyroid carcinoma

BACKGROUND

Findings of mediastinal uptake of 131I after surgical treatment for differentiated thyroid carcinoma (DTC) are common, especially in young patients. Given the frequency of false-positive findings, a protocol for diagnostic and therapeutic strategies would be useful. With the goal of accurately selecting management strategies, the authors analyzed their data and data found elsewhere in the literature for correlations with the incidence of mediastinal 131I uptake and with treatment for patients exhibiting such 131I uptake.

METHODS

All patients with DTC who were treated between 1978 and 2000 at Groningen University Hospital (Groningen, The Netherlands) and who received adjuvant 131I ablation therapy were included in the current analysis, which involved retrospective review of all relevant data.

RESULTS

Five hundred four patients with DTC initially underwent total thyroidectomy, with additional 131I ablation performed for 489 of these patients. In 48 of 489 patients (9.8%), 131I uptake was seen in the mediastinum on a posttreatment scan. Analysis of those 48 patients and of cases in the literature demonstrated that serum thyroglobulin levels, risk status, and the presence of thymus on radiologic images were important in the surgical decision-making process.

CONCLUSIONS

Mediastinal uptake of 131I on posttreatment scans was found in approximately 10% of patients after total thyroidectomy for DTC. Based on the current data and the data presented in the literature, the authors developed a flow chart for determining appropriate treatment strategies, which included mediastinal dissection for high-risk patients and for patients with serum thyroglobulin levels > 10 ng/mL.

Preoperative plasma concentrations of vascular endothelial growth factor and matrix metalloproteinase 9 are associated with stage progression in papillary thyroid cancer

OBJECTIVE

Vascular endothelial growth factor (VEGF), a potent angiogenic peptide, and matrix metalloproteinase 9 (MMP-9), a proteolytic enzyme, are found to be abundantly expressed in several types of cancer and correlate with tumour progression. In this study, we investigated the relationship between preoperative plasma VEGF, MMP-9 levels and disease stages in papillary thyroid cancer.

DESIGN

Plasma samples were consecutively collected from 30 patients with papillary thyroid cancer preoperatively (seven males and 23 females with a mean age of 45 +/- 16 years) and control plasmas obtained from 30 patients with benign goitre (seven males and 23 females with a mean age of 44 +/- 18 years) and 23 healthy persons (four males and 19 females with a mean age 44 +/- 15 years). Plasma VEGF and MMP-9 concentrations were determined by enzyme-linked immunosorbent assay. Cancer progression was staged by the TNM classification of the American Joint Committee on Cancer (AJCC) and the International Union Against Cancer (UICC).

RESULTS

In thyroid cancer patients, the plasma VEGF and MMP-9 values were higher than those in controls (51.8 +/- 11.5 ng/l vs. 27.0 +/- 0.8 ng/l; 72.3 +/- 23.3 micro g/l vs. 22.1 +/- 3.0 micro g/l, respectively; P < 0.05), and those in benign goitre (51.8 +/- 11.5 ng/l vs. 39.7 +/- 8.8 ng/l; 72.3 +/- 23.3 micro g/l vs. 23.0 +/- 2.2 micro g/l, respectively; P < 0.05). But, there was no difference of plasma VEGF and MMP-9 between patients with goitre and normal subjects. A comparison of VEGF and MMP-9 levels in patients at each cancer stage and in patients with benign nodule found that plasma VEGF and MMP-9 values in TNM stages III and IV, but not stage I or II, were significantly elevated (P < 0.05). When cancer patients were grouped according to clinopathological features, the plasma VEGF and MMP-9 concentrations were both significantly elevated in patients with large tumour size (P < 0.01), lymph node involvement (P < 0.01), extrathyroidal invasion (P < 0.05), distant metastasis (P < 0.05) or advanced stages (P < 0.01).

CONCLUSION

Our study demonstrated that circulating VEGF and MMP-9 levels correlated with progression of papillary thyroid cancer, suggesting plasma VEGF and MMP-9 may serve as preoperative adjuvant markers for assessing disease activity in papillary thyroid cancer. However, they should not be used as a diagnostic tool for differentiating malignant from benign thyroid disorders.

Staging and prognostic factor evaluation in soft tissue sarcoma

Over the past decade, there has been significant emphasis on the elucidation of clinicopathologic prognostic factors in STS. This has allowed for identification of the "high-risk" patient at presentation. Molecular factors may further refine the identification of high-risk patients. Setting-related prognostic factors are often amenable to change, and all STS patients should probably be referred for specialty consultation before treatment so that they can benefit from optimal diagnostic, therapeutic, and multidisciplinary approaches. The ongoing pursuit of prognostic issues should also recognize the dynamic nature of prognosis course in a patient's disease.

Thyroid carcinoma

Thyroid carcinomas are fairly uncommon and include disease types that range from indolent localised papillary carcinomas to the fulminant and lethal anaplastic disease. Several attempts to formulate a consensus about treatment of thyroid carcinoma have resulted in published guidelines for diagnosis and initial disease management. Multimodality treatments are widely recommended, although there is little evidence from prospective trials to support this approach. Surgical resection to achieve local disease control remains the cornerstone of primary treatment for most thyroid cancers, and is often followed by adjuvant radioiodine treatment for papillary and follicular types of disease. Thyroid hormone replacement therapy is used not only to rectify postsurgical hypothyroidism, but also because there is evidence to suggest that high doses that suppress thyroid stimulating hormone prevent disease recurrence in patients with papillary or follicular carcinomas. Treatment for progressive metastatic disease is often of limited benefit, and there is a pressing need for novel approaches in treatment of patients at high risk of disease-related death. In families with inherited thyroid cancer syndromes, early diagnosis and intervention based on genetic testing might prevent poor disease outcomes. Care should be carefully coordinated by members of an experienced multidisciplinary team, and patients should be provided with education about diagnosis, prognosis, and treatment options to allow them to make informed contributions to decisions about their care.

Well-differentiated carcinoma of the thyroid

Thyroid cancer will be diagnosed in more than 20,000 individuals in the United States in 2002. Approximately 16,000 of these patients will be women. During the same year, an estimated 1300 deaths from thyroid cancer are expected. The various types of thyroid cancer include papillary carcinoma, follicular carcinoma, Hurthle cell carcinoma, medullary carcinoma, anaplastic carcinoma, and thyroid lymphoma. Papillary, follicular, and Hurthle cell carcinoma are considered well-differentiated thyroid cancers and constitute the focus of this article.

Diagnosis of neck recurrences in patients with differentiated thyroid carcinoma

BACKGROUND

The follow-up of patients with differentiated thyroid carcinoma (DTC) is traditionally carried out with (131)I whole body scan ((131)I WBS) and serum thyroglobulin (Tg) measurement. Neck ultrasonography (US) is also used.

METHODS

We compared the roles of Tg measurement (IRMA assay) after l-thyroxine (T4) withdrawal, (131)I WBS, and US in the diagnosis of DTC neck recurrences. Diagnosis of DTC neck recurrences was based on fine-needle aspiration biopsy (FNAB) or on histologic results. Four hundred ninety-four DTC patients (120 males, 374 females; mean age, 49.3 years), submitted to total thyroidectomy and subsequent radioablative (131)I treatment, underwent serum Tg measurement off T4 therapy, (131)I WBS, and neck US at our institution. Mean (+/- SD) follow-up time was 55.1 +/- 37.7 months. Neck DTC recurrences were detected in 51 (10.3%) patients (34 females, 17 males; mean age, 49.5 years).

RESULTS

Neck recurrences occurred after 44.6 +/- 21.4 months from initial treatment. Serum Tg levels increased (> or = 2 ng/mL) off T4 therapy in 29 patients (sensitivity 56.8%), (131)I WBS showed neck uptake in 23 patients (sensitivity 45.1%) and coexisting distant metastases were detected in 9 of 23 patients, and US identified neck recurrence in 48 patients (sensitivity 94.1%). Of these 48 neck recurrences, 19 were found in the laterocervical compartment and 29 in the central neck compartment.

CONCLUSIONS

Traditional techniques for the surveillance of DTC patients are not as sensitive as US in the detection of neck recurrences. Neck US detects recurrences in patients with undetectable serum Tg levels and negative IWBS and should be performed as the first-line test in the follow-up of all DTC patients.

Prognostic Factors in Mortality and Morbidity in Patients with differentiated Thyroid Cancer

We attempted to determine if women younger than 45 years of age who have isolated papillary thyroid cancer and whose tumors are smaller than 4 cm (T2N0M0) are at low risk for mortality and morbidity following thyroid lobectomy. To this end, we analyzed information on both women and men obtained from our review of the literature, and we integrated it with data compiled in the Delaware Cancer Registry. We performed a secondary analysis to determine if the risk of death and recurrence can be predicted on the basis of age, tumor size, sex, histology, and the type of operation. We found that among patients who had undergone either thyroid lobectomy or total thyroidectomy, mortality rates were 1.3% for those younger than 45 years of age and 15.6% for those 45 years and older (p< 0.0001). With respect to tumor size, patients whose masses were smaller than 4 cm had significantly lower mortality (3.0%) and recurrence (11.1%) rates than did those whose tumors were 4 cm or larger (16.8 and 33.3%, respectively; p< 0.0001). Other significant risk factors for death were male sex and the presence of follicular thyroid cancer (as opposed to papillary thyroid cancer). The risk of permanent hypocalcemia was significant among patients who had undergone total thyroidectomy, but not among those who had been treated with lobectomy. The subgroup of patients who had the lowest risk of mortality and morbidity was made up of women younger than 45 years who had a papillary thyroid tumor smaller than 4 cm that was limited to one lobe and who had undergone lobectomy. On the other hand, we found that lobectomy might carry a higher risk of recurrence (from a micrometastasis in the cervical lymph node) than does total thyroidectomy. Experienced surgeons whose rates of hypocalcemia and recurrent laryngeal nerve paralysis following total thyroidectomy are low offer their patients the unambiguous advantage of superior follow-up with thyroglobulin and radioactive iodine.

Presurgical assessment of the tumor burden of familial medullary thyroid carcinoma by calcitonin testing

BACKGROUND

Early diagnosis of familial medullary thyroid carcinoma (MTC) is currently done by genetic analysis. These techniques have replaced calcitonin stimulation testing, which was previously used for this purpose. Some studies suggest a relationship between MTC spread and calcitonin levels. The aim of this study was to assess whether the tumor burden of MTC associated with multiple endocrine neoplasia type 2A (MEN 2A) syndrome can be estimated from the plasma calcitonin values before surgery.

STUDY DESIGN

We retrospectively studied the relationship of basal and peak calcitonin values before thyroidectomy with histopathologic findings in 53 patients with MEN 2A syndrome from 14 families. The MTC was classified according to TNM staging. Analysis of variance was used for statistical analysis complemented with equality contrasts for pairs of means by the least significant difference method with a Student's t-test and with the Bonferroni's adjustment.

RESULTS

A positive association was found between tumor stage and basal and peak calcitonin levels. There were significant differences between the following: mean basal concentrations of patients with C cell hyperplasia (CCH) (34.3 pg/mL) and TNM stage II (1,097.4 pg/mL), p < 0.01; CCH and TNM stage III (2,940.8 pg/mL), p < 0.001; TNM stage I (165.3 pg/mL) and stage II (1,097.4 pg/mL), p < 0.01, and between TNM stages I and III, p < 0.001. Poststimulation mean concentrations were different between CCH (48.7 pg/mL) and TNM I (514.2 pg/mL), p < 0.001.

CONCLUSIONS

Preoperative calcitonin testing may be useful for assessing tumor spread and should be considered when deciding the extent of surgery for MEN 2A MTC.

Papillary thyroid carcinoma: prognostic factors and the role of radioiodine and external radiotherapy

PURPOSE

To evaluate the role of radioiodine and external radiotherapy treatment in papillary thyroid carcinoma (PTC).

METHODS AND MATERIALS

This is a retrospective study of 842 patients with the diagnosis of PTC registered from 1960 to 1997 at the Department of Clinical Oncology, Queen Elizabeth Hospital, Hong Kong. The mean follow-up was 9.2 years. The stage distribution according to UICC/AJCC TNM staging was as follows: 58.6%, Stage I; 9.6%, Stage II; 26.1%, Stage III; 2.3%, Stage IV; and 3.4%, not stated.

RESULTS

The 10-year cause-specific survival (CSS) rates were as follows: Stage I, 99.8%; Stage II, 91.8%; Stage III, 77.4%; and Stage IV, 37.1%. Multivariate analysis showed that the statistically significant poor prognostic factors for CSS were as follows: age older than 45, postoperative gross locoregional (LR) residual disease, distant metastasis (DM) at presentation, and lack of radioactive iodine (RAI) treatment. In patients with no DM and no postoperative LR disease, adjuvant RAI ablation reduced both LR failure (RR [relative risk] = 0.29) and DM (RR = 0.2), although the CSS was not affected. In the subgroup of T1N0 M0 disease, no patient with RAI treatment had a relapse. External radiotherapy reduced the risk of LR failure to 0.35. Subgroup analysis revealed that external radiotherapy was particularly effective in increasing the probability of LR control of disease in patients with gross postoperative LR disease (RR = 0.36).

CONCLUSIONS

Both RAI and external radiotherapy were effective treatment in PTC. Total or near-total thyroidectomy followed by RAI treatment appears to result in the best outcome. External radiotherapy to improve LR control is indicated in patients with gross postoperative residual disease. Treatment should be individualized for patients with T1N0 M0 disease.

Papillary and follicular thyroid carcinoma

Papillary and follicular thyroid carcinomas are among the most curable of all cancers. However, some patients are at high risk of recurrence or even death from their cancer. Most of these patients can be identified at the time of diagnosis using well-established prognostic indicators. The extent of initial treatment and follow-up should therefore be individualized. The early discovery of persistent and recurrent disease is based on the combined use of serum thyroglobulin determination and of total body scanning with 131I. The recent availability of recombinant human thyroid stimulating hormone has greatly improved the quality of the patient's life during follow-up. Treatment of recurrences is based mainly on surgery and 131I treatment.

Is familial non-medullary thyroid carcinoma more aggressive than sporadic thyroid cancer? A multicenter series

BACKGROUND

The aggressiveness of familial non-medullary thyroid cancer (FNMTC) has been a subject of debate. The purpose of the study was to determine whether FNMTC is more aggressive than sporadic thyroid cancer.

METHODS

A multicenter retrospective matched-case control study of FNMTC versus sporadic non-medullary thyroid cancer was conducted. Disease-free survival (time to recurrence) for both groups was compared.

RESULTS

Forty-eight familial cases were compared with 144 age-, gender-, and stage-matched controls. Patients with FNMTC had a significantly shorter disease-free survival compared with sporadic non medullary thyroid cancer. Patients with FNMTC who presented with evidence of distant metastasis, or who were from families with more than 2 thyroid cancer-affected members, had the worst prognosis. The available staging systems were less likely to predict the outcome in patients with FNMTC than in patients with sporadic non-medullary thyroid cancer unless one accounted for the strength of family history in the staging system.

CONCLUSIONS

FNMTC is more aggressive than sporadic non-medullary thyroid cancer. The best predictors of a poor outcome in patients with FNMTC are the number of family members affected by thyroid cancer and evidence of distant metastasis.

Over-expression of hepatocyte growth factor/scatter factor (HGF/SF) and the HGF/SF receptor (cMET) are associated with a high risk of metastasis and recurrence for children and young adults with papillary thyroid carcinoma

OBJECTIVE

The study determined if hepatocyte growth factor/scatter factor (HGF/SF) or the HGF/SF receptor (cMET) might be important for metastasis in thyroid cancer.

DESIGN

We examined HGF/SF and cMET expression by immunohistochemistry in a retrospective group of benign and malignant thyroid lesions from children and young adults, and correlated the intensity of expression with clinical outcome.

PATIENTS

Patients included 42 children and young adults with papillary thyroid carcinomas (PTC), seven with follicular thyroid carcinomas (FTC), two with medullary thyroid carcinomas (MTC), 14 with benign thyroid disorders, and two with normal thyroids.

MEASUREMENTS

Expression of cMET was graded from 0 (absent) to 4 (intense); and HGF/SF expression was graded from 0 (absent-minimal) to 3 (diffuse and intense).

RESULTS

cMET staining was greater in PTC (mean intensity 2.3 +/- 0.4 vs. 0.8 +/- 0.2, P < 0.005) and FTC (2.4 +/- 0.6 vs. 0.8 +/- 0.2, P = 0.04) than benign lesions (0.8 +/- 0.2) or normal thyroids (0.4 +/- 0.5). PTC with intense cMET staining had shorter disease free survival (P = 0.05) and increased HGF/SF staining (r = 0.39, P = 0.017). HGF/SF correlated with the extent of disease at diagnosis (r = 0.33, P = 0.049). Patients with PTC were stratified into quartiles based on combined cMET and HGF/SF staining. Those with intense cMET and HGF/SF staining were younger (P = 0.05), and had reduced disease free survival (P = 0.03).

CONCLUSIONS

We conclude that increased cMET and HGF/SF expression is associated with a high risk for metastasis and recurrence in children and young adults with papillary thyroid carcinoma.

A comparison of staging systems for localized extremity soft tissue sarcoma

BACKGROUND

Staging systems for soft tissue sarcoma (STS) are important to identify patients with similar systemic risk who might benefit from specific treatments. This study compared four commonly used staging systems for predicting systemic outcomes of patients with localized extremity STS, as proposed by the fourth and fifth editions of the American Joint Committee on Cancer/International Union Against Cancer (AJCC/UICC) staging system, the Memorial Sloan-Kettering Cancer Center (MSK) system, and the Surgical Staging System (SSS) of the Musculoskeletal Tumor Society.

METHODS

Three hundred consecutive adult patients with newly diagnosed nonmetastatic STS of the lower extremity were treated at Memorial Sloan-Kettering Cancer Center between 1982 and 1989. Metastasis free survival was the end point of the study. The prognostic value of the four staging systems and their components were examined in univariate and multivariate analyses. The Akaike information criterion (AIC) was used to identify the system that best predicted the risk of systemic recurrence.

RESULTS

Compartment status, depth, grade, and size were all independent predictors of outcome within their respective staging systems. However, when compared with one another, only depth, grade, and size retained their prognostic significance. Of the four models, the AIC predicted that the MSK was the best predictor of systemic relapse, followed by the fifth edition of the AJCC/UICC staging system.

CONCLUSIONS

Staging systems such as the MSK system or the fifth edition of the AJCC/UICC system, which include tumor depth, grade, and size as prognostic factors, are the most predictive of systemic relapse in patients presenting with localized extremity STS. Both of these systems identify the same group of patients at the highest risk who would be the most suitable for adjuvant chemotherapy trials.

Prognostic indicators in differentiated thyroid carcinoma

BACKGROUND

Thyroid cancer ranges from well-differentiated lesions with an excellent prognosis to anaplastic carcinoma, which is almost uniformly fatal. Thus, methods to assess the behavior of thyroid malignancies are necessary to arrive at appropriate treatment decisions.

METHODS

We discuss the factors that affect the prognosis of patients with well-differentiated thyroid malignancies, including papillary, follicular, Hürthle cell, and medullary thyroid carcinomas. We also review the presentation, therapy, and outcome of patients seen at our center over a span of 50 years. These data have identified those prognostic factors that are predictive of survival and recurrence in differentiated thyroid cancer.

RESULTS

Several classifications with different variables have been developed to define risk-group categories. Three widely used systems, in addition to the TNM staging system, include AGES, AMES, and MACIS.

CONCLUSIONS

A better understanding of independently important prognostic variables will result in improved patient care and treatment.

Medullary thyroid carcinoma: clinical characteristics, treatment, prognostic factors, and a comparison of staging systems

BACKGROUND

The clinical courses of patients with medullary thyroid carcinoma (MTC) vary, and a number of prognostic factors have been studied, but the significance of some of these factors remains controversial.

METHODS

The study group consisted of 104 patients with MTC or C-cell hyperplasia managed at the hospitals of the University of California, San Francisco, between January 1960 and December 1998. Patients were classified as having sporadic MTC, familial non-multiple endocrine neoplasia (MEN) MTC, MEN 2A, or MEN 2B. The TNM, European Organization for Research and Treatment of Cancer (EORTC), National Thyroid Cancer Treatment Cooperative Study (NTCTCS), and Surveillance, Epidemiology, and End Results (SEER) extent-of-disease stages were determined for each patient. The predictive values of these staging or prognostic scoring systems were compared by calculating the proportion of variance explained (PVE) for each system.

RESULTS

Fifty-six percent of the patients had sporadic MTC, 22% had familial MTC, 15% had MEN 2A, and 7% had MEN 2B. The overall average age at diagnosis was 38 years, and patients with sporadic MTC presented at an older age (P < 0.05). Thirty-two percent of the patients with hereditary MTC were diagnosed by screening (genetic and/or biochemical). These patients had a lower incidence of cervical lymph node metastasis (P < 0.05) and 94.7% were cured at last follow-up (P < 0.0001) compared with patients not screened. Patients with sporadic MTC who had systemic symptoms (diarrhea, bone pain, or flushing) had widely metastatic MTC and 33.3% of those patients died within 5 years. Overall, 49.4% of the patients were cured, 12.3% had recurrent MTC, and 38.3% had persistent MTC. The mean follow-up time was 8.6 years (median, 5.0 years) with 10.7% (n=11) and 13.5% (n=14) cause specific mortality at 5 and 10 years, respectively. Patients with persistent or recurrent MTC who died of MTC lived for an average of 3.6 years (ranging from 1 month to 23.7 years). Patients who had total or subtotal thyroidectomy were less likely to have persistent or recurrent MTC (P < 0.05), and patients who had total thyroidectomy with cervical lymph node clearance required fewer reoperations for persistent or recurrent MTC (P < 0.05) than patients who underwent lesser procedures. In univariate analysis, age, gender, clinical presentation, TNM stage, sporadic/hereditary MTC, distant metastasis, and extent of thyroidectomy were significant prognostic factors. Only age and stage, however, remained independent prognostic factors in multivariate analysis. The TNM, EORTC, NTCTCS, and SEER staging systems were all accurate predictors of survival, but the EORTC prognostic scoring system had the highest PVE in this cohort.

CONCLUSIONS

Screening for MTC and early treatment (total thyroidectomy with central neck lymph node clearance) had nearly a 100% cure rate. Patients with postoperative hypercalcitoninemia without clinical or radiologic evidence of residual tumor after apparently curative surgery may enjoy long term survival but have occult MTC. Only patient age at presentation and TNM stage were independent predictors of survival. The EORTC criteria, which included the greatest number of significant prognostic factors in our cohort, had the highest predictive value.

Toward a standard clinicopathologic staging approach for differentiated thyroid carcinoma

Physicians attempting disease staging for differentiated thyroid carcinoma have a broad variety of clinicopathologic classification approaches from which to choose. Unfortunately, no consensus has yet emerged as to the optimal method, and considerable differences of opinion still exist. Eight of the most commonly used classifications are described, along with results of recent comparative analyses of multiple schemes. Recommendations are provided to permit standardized approaches to clinicopathologic staging, and future research directions are identified.

Advances in the pathogenesis and treatment of thyroid cancer

Thyroidectomy remains the mainstay of treatment for thyroid carcinoma. The extent of surgical resection, however, remains controversial as most patients will have excellent long-term prognosis and because some of the standard staging and prognostic information are not available at the time of surgical resection. The different staging and risk group definitions for thyroid carcinoma are not superior to the Tumor-Node-Metastasis classification of the American Joint Commission in Cancer (AJCC), which is universally available and accepted and should be used to report treatment outcomes. Recent advances in the molecular pathogenesis of thyroid malignancy will help identify high-risk patients who would benefit from aggressive surgical resection and adjuvant treatment.

Prospective multicenter study of thyroiscarcinoma treatment: initial analysis of staging and outcome. National Thyroid Cancer Treatment Cooperative Study Registry Group

BACKGROUND

A novel prognostic staging classification encompassing all forms of thyroid carcinoma was created for the National Thyroid Cancer Treatment Cooperative Study (NTCTCS) Registry, with the goal of prospective validation and comparison with other available staging classifications.

METHODS

Patient information was recorded prospectively from 14 institutions. Clinicopathologic staging was based on patient age at diagnosis, tumor histology, tumor size, intrathyroidal multifocality, extraglandular invasion, metastases, and tumor differentiation.

RESULTS

Between 1987 and 1995, 1607 patients were registered. Approximately 43% of patients were classified as NTCTCS Stage I, 24% Stage II, 24% Stage III, and 9% Stage IV. Patients with follicular carcinoma were more likely to have "high risk" Stage III or IV disease than those with papillary carcinoma. Of 1562 patients for whom censored follow-up was available (median follow-up, 40 months), 78 died of thyroid carcinoma or complications of its treatment. Five-year product-limit patient disease specific survival was 99.8% for Stage I, 100% for Stage II, 91.9% for Stage III, and 48.9% for Stage IV (P < 0.0001). The frequency of remaining disease free also declined significantly with increasing stage (94.3% for Stage I, 93.1%for Stage II, 77.8% for Stage III, and 24.6% for Stage IV). The same patients also were staged applying six previously published classifications as appropriate for their tumor type. The predictive value of the NTCTCS Registry staging classification consistently was among the highest for disease specific mortality and for remaining disease free, regardless of the tumor type.

CONCLUSIONS

The NTCTCS Registry staging classification provides a prospectively validated scheme for predicting short term prognosis for patients with thyroid carcinoma.