RESUMO
BACKGROUND: Age is a critical factor in outcome for patients with well-differentiated thyroid cancer. Currently, age 45 years is used as a cutoff in staging, although there is increasing evidence to suggest this may be too low. The aim of this study was to assess the potential for changing the cut point for the American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) staging system from 45 years to 55 years based on a combined international patient cohort supplied by individual institutions. METHODS: A total of 9484 patients were included from 10 institutions. Tumor (T), nodes (N), and metastasis (M) data and age were provided for each patient. The group was stratified by AJCC/UICC stage using age 45 years and age 55 years as cutoffs. The Kaplan-Meier method was used to calculate outcomes for disease-specific survival (DSS). Concordance probability estimates (CPE) were calculated to compare the degree of concordance for each model. RESULTS: Using age 45 years as a cutoff, 10-year DSS rates for stage I-IV were 99.7%, 97.3%, 96.6%, and 76.3%, respectively. Using age 55 years as a cutoff, 10-year DSS rates for stage I-IV were 99.5%, 94.7%, 94.1%, and 67.6%, respectively. The change resulted in 12% of patients being downstaged, and the downstaged group had a 10-year DSS of 97.6%. The change resulted in an increase in CPE from 0.90 to 0.92. CONCLUSIONS: A change in the cutoff age in the current AJCC/UICC staging system from 45 years to 55 years would lead to a downstaging of 12% of patients, and would improve the statistical validity of the model. Such a change would be clinically relevant for thousands of patients worldwide by preventing overstaging of patients with low-risk disease while providing a more realistic estimate of prognosis for those who remain high risk.
Assuntos
Diferenciação Celular , Técnicas de Apoio para a Decisão , Estadiamento de Neoplasias/métodos , Neoplasias da Glândula Tireoide/patologia , Fatores Etários , Brasil , Intervalo Livre de Doença , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , New South Wales , América do Norte , Valor Preditivo dos Testes , Reprodutibilidade dos Testes , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Neoplasias da Glândula Tireoide/mortalidade , Neoplasias da Glândula Tireoide/terapia , Resultado do TratamentoRESUMO
Medullary thyroid cancer (MTC) compromises 3-5% of all thyroid cancers and arises from parafollicular or calcitonin-producing C cells. It may be sporadic (75% of cases), or may occur as a manifestation of either the hereditary syndrome Multiple Endocrine Neoplasia type 2 (MEN 2A or MEN 2B) (25% of cases), or rarely as an isolated familial syndrome (FMTC). Complete surgical resection comprising in most cases total thyroidectomy with central lymph node dissection at an early stage of the disease is the only potential cure for MTC. The familial form of the disease, MEN-2A occupies a unique place in surgical history, having been the first disease where surgical removal of an affected organ was undertaken before the development of malignancy, solely on the basis of genetic testing. Total thyroidectomy prior to the development of invasive cancer completely avoids an otherwise lethal malignancy. Timing of prophylactic surgery is based on models that utilise genotype-phenotype correlations, which have now been stratified into three risk groups based on the specific codon involved. MTC should be followed with postoperative serial serum calcitonin levels to survey for persistent or recurrent disease as indicated by detectable levels. The challenge however, if calcitonin levels are increased, is to find the source of its production. The first localisation technique recommended would be ultrasound of the neck, since there is a high frequency of local recurrence and cervical node metastasis, followed by a total body CT scan and bone scintigraphy.
Assuntos
Carcinoma Medular/cirurgia , Neoplasia Endócrina Múltipla Tipo 2a/cirurgia , Neoplasias da Glândula Tireoide/cirurgia , Tireoidectomia , Humanos , Esvaziamento Cervical , Recidiva Local de Neoplasia/diagnóstico , Proteínas Proto-Oncogênicas c-ret/genéticaRESUMO
Medullary thyroid cancer (MTC) compromises 3-5 percent of all thyroid cancers and arises from parafollicular or calcitonin-producing C cells. It may be sporadic (75 percent of cases), or may occur as a manifestation of either the hereditary syndrome Multiple Endocrine Neoplasia type 2 (MEN 2A or MEN 2B) (25 percent of cases), or rarely as an isolated familial syndrome (FMTC). Complete surgical resection comprising in most cases total thyroidectomy with central lymph node dissection at an early stage of the disease is the only potential cure for MTC. The familial form of the disease, MEN-2A occupies a unique place in surgical history, having been the first disease where surgical removal of an affected organ was undertaken before the development of malignancy, solely on the basis of genetic testing. Total thyroidectomy prior to the development of invasive cancer completely avoids an otherwise lethal malignancy. Timing of prophylactic surgery is based on models that utilise genotype-phenotype correlations, which have now been stratified into three risk groups based on the specific codon involved. MTC should be followed with postoperative serial serum calcitonin levels to survey for persistent or recurrent disease as indicated by detectable levels. The challenge however, if calcitonin levels are increased, is to find the source of its production. The first localisation technique recommended would be ultrasound of the neck, since there is a high frequency of local recurrence and cervical node metastasis, followed by a total body CT scan and bone scintigraphy.
O carcinoma medular de tiróide (CMT) abrange 3-5 por cento do câncer de tiróide em geral e surge da célula parafolicular ou célula C produtora de calcitonina. Pode ser esporádico (75 por cento dos casos), ou pode ocorrer como uma das manifestações das síndromes hereditárias Neoplasia Endócrina Múltipla tipo 2 (NEM2A ou NEM2B) (25 por cento dos casos), ou mais raramente como uma síndrome familiar isolada (CMTF). A ressecção cirúrgica completa, que na maioria dos casos consiste de tireoidectomia total com dissecção dos linfonodos nos estágios precoces da doença, é a única forma de cura potencial de CMT. A forma de doença familiar da patologia NEM2A ocupa um lugar único na história da cirurgia, tendo sido a primeira doença onde a remoção cirúrgica de um órgão afetado foi realizada antes do desenvolvimento da malignidade, baseado somente no teste genético. A tireoidectomia total antes do desenvolvimento do câncer invasivo evita de outra forma a malignidade letal. A época da cirurgia profilática está baseada nos modelos que utilizam a correlação genótipo-fenótipo, que atualmente está estratificada em três grupos de risco baseado no códon envolvido. O CMT deve ser acompanhado após a cirurgia com dosagem de calcitonina sérica, cujo nível, quando detectável, indicaria a persistência ou recorrência da doença. O desafio, no entanto, se os níveis de calcitonina estão elevados, é encontrar a fonte desta produção. A primeira técnica de localização recomendada seria o ultrassom do pescoço, já que ocorre uma alta freqüência de recorrência local e de metástase dos nódulos cervicais, seguida de tomografia computadorizada do corpo inteiro e de cintilografia óssea.