Survival and prognostic factors in differentiated thyroid cancer--a multivariate analysis of 1,055 cases

Differentiating pulmonary metastasis from benign lung nodules in thyroid cancer patients using dual-energy CT parameters

OBJECTIVES

To explore the importance of quantitative characteristics of dual-energy CT (DECT) between pulmonary metastasis and benign lung nodules in thyroid cancer.

METHODS

In this retrospective study, we identified 63 patients from our institution's database with pathologically proven thyroid cancer who underwent DECT to assess pulmonary metastasis. Among these patients, 22 had 55 pulmonary metastases, and 41 had 97 benign nodules. If nodules showed increased iodine uptake on I-131 single-photon emission computed tomography-computed tomography or increased size in follow-up CT, they were considered metastatic. We compared the clinical findings and DECT parameters of both groups and performed a receiver operating characteristic analysis to evaluate the optimal cutoff values of the DECT parameters.

RESULTS

Patients with metastases were significantly older than patients with benign nodules (p = 0.048). The DECT parameters of the metastatic nodules were significantly higher than those of the benign nodules (iodine concentration [IC], 5.61 ± 2.02 mg/mL vs. 1.61 ± 0.98 mg/mL; normalized IC [NIC], 0.60 ± 0.20 vs. 0.16 ± 0.11; NIC using pulmonary artery [NIC_PA], 0.60 ± 0.44 vs. 0.15 ± 0.11; slope of the spectral attenuation curves [λHU], 5.18 ± 2.54 vs. 2.12 ± 1.39; and Z-effective value [Z_eff], 10.0 ± 0.94 vs. 8.79 ± 0.75; all p < 0.001). In the subgroup analysis according to nodule size, all DECT parameters of the metastatic nodules in all subgroups were significantly higher than those of the benign nodules (all p < 0.05). The cutoff values for IC, NIC, λHU, NIC_PA, and Z_eff for diagnosing metastases were 3.10, 0.29, 3.57, 0.28, and 9.34, respectively (all p < 0.001).

CONCLUSIONS

DECT parameters can help to differentiate metastatic and benign lung nodules in thyroid cancer.

KEY POINTS

• DECT parameters can help to differentiate metastatic and benign lung nodules in patients with thyroid cancer. • DECT parameters showed a significant difference between benign lung nodules and lung metastases, even for nodules with diameters ≥ 3 mm and < 5 mm. • Among the DECT parameters, the highest diagnostic accuracy for differentiating pulmonary metastases from benign lung nodules was achieved with the NIC and IC, followed by the NIC_PA and λHU, and their cutoff values were 0.29, 3.10, 0.28, and 3.57, respectively.

Distant Metastases in Differentiated Thyroid Cancer: Long-term Results of Radioiodine Treatment and Statistical Analysis of Prognostic Factors in 214 Patients

Long-term results and statistical analysis of prognostic factors in a series of 214 patients with distant metastases from differentiated thyroid cancer (DTC) are reported here. These 214 were part of a total series of 1457 patients with DTC referred to our center from 1967 to 1987. All patients underwent surgery and 131-I therapy and were treated with TSH suppressive doses of thyroid hormones. After a mean follow-up of 7.3 years including clinical, scintigraphic, radiological and laboratory investigations, 24.4% of patients were alive without disease, 36.5% alive with disease, 1.8% dead without disease and 37.3% dead with disease. One of the main factors influencing the survival in our series was 131-I uptake (RIU) by metastatic tissue. No case of complete remission of disease was observed among patients with nonfunctioning metastases. Another important factor was the site of metastases, patients with bone metastases having the worst prognosis. The patient's age at diagnosis represented another important factor for survival; patients over 40 years, particularly those over 60 years had a bad prognosis. A clear interrelation was found among the factors advanced age, nonfunctioning metastases and bone metastases. Patients with these last clinical features were considered to be at high risk and generally had a fatal outcome. Another significant prognostic factor revealed by univariate analysis was the histologic type. Patients with follicular tumor showed a poorer prognosis in comparison to papillary tumor. When multivariate analysis was applied, the factors age at diagnosis, site of metastases and RIU proved to have a significant influence on survival, but not the histologic type. Lastly, the relative rate of males was higher in the group of patients with metastases in comparison to the whole series of DTC patients. Despite this, the factor sex did not influence survival.

A meta-analysis of prognostic roles of molecular markers in papillary thyroid carcinoma

The prognostic role of molecular markers in papillary thyroid carcinoma (PTC) is a matter of ongoing debate. The aim of our study is to investigate the impact of RAS, BRAF, TERT promoter mutations and RET/PTC rearrangements on the prognosis of PTC patients. We performed a search in four electronic databases: PubMed, Scopus, Web of Science and Virtual Health Library (VHL). Data of hazard ratio (HR) and its 95% confidence interval (CI) for disease-specific survival (DSS) and disease-free survival (DFS) were directly obtained from original papers or indirectly estimated from Kaplan-Meier curve (KMC). Pooled HRs were calculated using random-effect model weighted by inverse variance method. Publication bias was assessed by using Egger's regression test and visual inspection of funnel plots. From 2630 studies, we finally included 35 studies with 17,732 patients for meta-analyses. TERT promoter mutation was significantly associated with unfavorable DSS (HR = 7.64; 95% CI = 4.00-14.61) and DFS (HR = 2.98; 95% CI = 2.27-3.92). BRAF mutations significantly increased the risk for recurrence (HR = 1.63; 95% CI = 1.27-2.10) but not for cancer mortality (HR = 1.41; 95% CI = 0.90-2.23). In subgroup analyses, BRAF mutation only showed its prognostic value in short-/medium-term follow-up. Data regarding RAS mutations and RET/PTC fusions were insufficient for meta-analyses. TERT promoter mutation can be used as an independent and reliable marker for risk stratification and predicting patient's outcomes. The use of BRAF mutation to assess patient prognosis should be carefully considered.

Sociodemographic Predictors of Survival in Differentiated Thyroid Cancer: Results from the SEER Database

Background. Differentiated thyroid carcinoma (DTC) is prognosticated upon a combination of tumor characteristics, such as histology and stage, and patient age. DTC is also notable for having a strong female predominance. Using a nationwide database with long follow-up times, we explored the interplay between tumor biology and patient characteristics in predicting mortality. Methods. The Surveillance, Epidemiology, and End Results (SEER) registry data 1973–2005 was examined for patients with DTC as their only known malignancy. Cox multivariate analyses were used to generate mortality hazard ratios to evaluate the effects of age, gender, ethnicity, and marital status. Results. We identified 55,995 patients with DTC as their only malignancy. Consistent with the existing literature, the tumors are primarily diagnosed in women (77.5%), and predominantly affect Caucasians (78.3%). Female gender had a protective effect resulting in a 37% decrease in mortality. Age at diagnosis predicted mortality over age 40. Black ethnicity was associated with a 51% increase in mortality compared to Caucasians. Conclusion. Multiple demographic factors predict mortality in patients with DTC after adjusting for tumor characteristics, and they appear to have complex interactions. Recognizing the importance of these factors may enable clinicians to better tailor therapy.

Follicular thyroid carcinoma in an iodine-replete endemic goiter region: a prospectively collected, retrospectively analyzed clinical trial

OBJECTIVE

To determine risk factors for presence of lymph node or distant metastases in patients with follicular thyroid cancer (FTC) at the time of diagnosis and whether there is a relationship between the type of tumor invasion and metastases.

SUMMARY BACKGROUND DATA

FTC often presents distant metastases at the initial diagnosis. As distant metastases are independent prognostic factors in a patient's survival, determination of clinicopathologic characteristics for patients who are at higher risk for developing metastases is of greater clinical importance.

METHODS

The prognostic significance of gender (male vs. female), age (<or=40 years vs. <40 years), tumor size (<or=40 mm vs. >40 mm), number of lesions (uni- vs. multifocality), type of invasion (minimally invasive vs. widely invasive), and oncocytic changes (with vs. without) were analyzed in 207 patients, according to presence of lymph node and distant metastases at the time of initial surgery. According to the type of invasion, the carcinoma-specific survival and the disease-free survival of minimally invasive (MI) and widely invasive (WI) FTC were estimated and compared.

RESULTS

None of the 127 patients with MI growth presented with lymph node metastases but 9.4% distant metastases. Overall risk factors for the presence of lymph node metastases at the initial diagnosis were multifocality (P = 0.02) and widely invasion (P = 0.0001) and for distant metastases age >45 years (P = 0.007), tumor size larger than 40 mm (P = 0.03) and widely invasion (P = 0.0001).WI-FTC patients show larger tumors (P = 0.0001), older age (P = 0.0001), and are presented more frequently in recurrent goiter disease (P = 0.0001). The estimated 10 years carcinoma-specific survival and disease-free survival for MI-tumors were significantly better than for WI-tumors (P = 0.0001).

CONCLUSIONS

Total thyroidectomy is recommended in all patients with FTC because of early distant metastases. Patients with WI-FTC need a more aggressive surgical treatment because of higher tendency for lymph node metastases. MI-FTC has an excellent prognosis with no sign of lymph node metastases, which emphasizes a limited need for nodal surgery.

Clinical importance of technetium-99m-methoxyisobutylisonitrile (MIBI) scintigraphy in differentiated thyroid carcinoma patients with elevated thyroglobulin levels and negative I-131 scanning results

AIMS AND BACKGROUND

The aim of this study was to evaluate the potential contribution of Tc-99m-MIBI scintigraphy to the follow-up of patients with differentiated thyroid carcinoma, who had elevated Tg levels and negative I-131 whole-body scan results.

MATERIALS AND METHODS

In this retrospective study, we evaluated 28 patients with differentiated thyroid carcinoma, who had total or near total thyroidectomy followed by an ablative dose of I-131 at various time intervals (15 women, 13 men; mean age 43 +/- 17 years). All patients were treated with T4 suppression. After a mean follow-up period of 6.1 years (range 3-15) all patients were determined to have a high serum Tg concentrations (>2 ng/ml) and previous negative I-131 WBS results. All patients were examined for metastatic sites using Tc-99m-MIBI scan. Scans were visually evaluated for detecting lymph node metastases and/or local recurrence, lung metastases and skeletal metastases.

RESULTS

Tc-99m-MIBI scan demonstrated lesions in 23 patients (83.3%). In five patients with negative Tc-99m-MIBI scan findings (FN results): Chest CT showed small-sized mediastinal LN metastases in 2 patients and lung metastases in another 2 patients (<1 cm). Neck CT showed small-sized cervical LN involvement in 1 patient. The sensitivity of detection for neck was 94.4%, for lung 63.6%, and for bone lesions 100%. For all scan sites taken together, the sensitivity of disease detection was 83.3%, the specificity was 50%, positive predictive value (PPV) was 96.2%, and finally negative predictive value (NPV) was 16.7%.

CONCLUSION

We concluded that Tc-99m-MIBI scan should be considered as a supplementary scintigraphic method for the follow-up of patients with high serum Tg levels and negative I-131 WBS results, and it can help clinicians in making the decision to treat these patients.

A model for predicting outcomes in patients with differentiated thyroid cancer and model performance in comparison with other classification systems

BACKGROUND

This study was performed to determine the prognostic factors for differentiated thyroid cancer, and to establish a mathematical prognostic model.

STUDY DESIGN

A retrospective study was conducted in 347 differentiated thyroid cancer patients. Univariate and multivariate prognostic factor analyses were carried out using the Kaplan-Meier and Cox regression methods.

RESULTS

Without adjustment for treatment in the multivariate analysis, age, tumor size, angioinvasion, and distant metastasis were significant predictors of outcomes. The very low-risk, low-risk, high-risk, and very high-risk groups were identified from the logistic regression equation. Overall and event-free survival estimations at 10 years were 100% and 100% for very low-risk patients, 88% and 75% for low-risk patients, 30% and 16% for high-risk patients, and 5% and 0% for very high-risk patients. Inclusion of treatment in the multivariate analysis showed, in addition to other variables, that both total or near total thyroidectomy (versus thyroidectomy less than total and near total thyroidectomy, p = 0.0002; hazard ratio, 0.4; 95% CI, 0.3-0.7) and adjuvant radioactive iodine treatment (versus no treatment with radioactive iodine, p = 0.0001; hazard ratio, 0.5; 95% CI, 0.2-0.8) were associated with a reduced hazard of death in the followup period. By subgroup analysis, total and near total thyroidectomy, along with radioactive iodine, appeared to provide a survival benefit for all patients except those in the very low-risk group.

CONCLUSIONS

The proposed mathematical model is satisfactory for predicting outcomes. Total and near total thyroidectomy along with radioactive iodine treatment might provide a survival advantage for differentiated thyroid cancer, except for those with very low risk.

Follicular thyroid carcinoma: prognostic factors and the role of radioiodine

BACKGROUND

The objective of this study was to investigate the patterns of recurrence, various prognostic factors, and the role of radioiodine in the treatment of patients with follicular thyroid carcinoma (FTC).

METHODS

The clinical outcomes of 215 patients with FTC who were treated at a single institution were analyzed retrospectively. The mean follow-up was 10.8 years.

RESULTS

The actuarial rates of cause specific survival (CSS), locoregional (LR) control, and freedom from distant metastasis (DM) at 10 years were 81%, 83%, and 72.3%, respectively. The independent prognostic factors for survival were metastasis at presentation (relative risk [RR], 47.7), radioiodine (RAI) treatment (RR, 0.25), extrathyroidal extension (RR, 3.8), and the postoperative absence of macroscopic disease in the neck region (RR, 0.06). In patients who were treated with RAI, both the LR failure rate (RR, 0.24) and the mortality rate (RR, 0.25) were reduced to about 25%. Subgroup analysis revealed that RAI improved the survival of patients with DM at presentation (RR, 0.17) and improved the LR control rate in patients who had no DM at presentation (RR, 0.13). For patients who underwent total thyroidectomy with negative resection margins, RAI significantly reduced the rate of LR recurrence (RR, 0.05). Patients with the minimally invasive type of FTC had a good prognosis. The 10-year rates for CSS, LR control, and freedom from DM were 97.6%, 100%, and 90.6%, respectively. The prognosis of patients with frankly invasive FTC was much poorer. The 10-year rates for CSS, LR control, and freedom from DM were 66.7%, 100%, and 45%, respectively.

CONCLUSIONS

RAI is an effective treatment for patients with FTC. It was associated with improved survival rates and fewer recurrences.

Single brain metastasis from thyroid cancer: report of twelve cases and review of the literature

Brain metastases from thyroid carcinoma is unusual, with a frequency of 1%. We report twelve patients, with single brain metastases and with a karnofsky performance scale score >60 at admission. No metastasis was seen during the uptake of iodine-131, even in the cases from differentiated thyroid carcinoma, suggesting absence of differentiation between primary and metastasic disease. The histopathology of thyroid carcinomas was anaplastic in five cases, differentiated in six, and medullary in one. Only in four patients, brain was the unique site of metastatic spread; in others, bones and lungs were also involved. All metastases were surgically removed, and all patients were treated with radiotherapy (45 Gy) in the postoperative course. The survival average was 19.8 months, and the quality of life was satisfactory in all patients. One patient remained alive till 5 years. Anaplastic histopathology and size of the primitive, and also bone involvement of thyroid disease were significant risk factors in our cases (p < 0.05). According to the literature, surgery is the best therapeutical choice. Alternative strategies in the management of brain metastasis, such as iodine-131 therapy, are discussed, paying particular attention to the relevant side effects.

Absence of mutations in the beta-catenin and adenomatous polyposis coli genes in papillary and follicular thyroid carcinomas

beta-Catenin has multiple functions both in intercellular adhesion and in signal transduction. As a signaling molecule, mutations in exon 3 of the beta-catenin gene stabilize this protein in the cytoplasm. Subsequently, accumulated beta-catenin protein translocates to nuclei with T-cell factor-4, and upregulates transcriptional activity of the target genes involved in carcinogenesis. Mutations in exon 3 of the beta-catenin gene have been detected in various carcinomas. We examined immunolocalization of beta-catenin protein and mutations in the beta-catenin and adenomatous polyposis coli (APC) genes in papillary carcinoma (25 cases), follicular carcinoma (two cases), and benign thyroid tumor (29 cases). We detected no mutation in exon 3 of the beta-catenin gene in both malignant and benign thyroid tumors by polymerase chain reaction (PCR) and direct sequencing. No mutations in the mutation cluster region of APC were found in any tumor samples analyzed. Immunohistochemically, beta-catenin showed membranous localization in most specimens. These results suggest that mutations of the beta-catenin and APC genes are rare and that activation of the Wnt signaling pathway may not contribute to pathogenesis in human papillary and follicular thyroid carcinomas.

Differentiated thyroid carcinoma in the elderly

The overall prognosis of patients with differentiated thyroid cancer is excellent, but the prognosis is rapidly worsening, when the disease is diagnosed in elderly patients. Old patients more often present with poor prognostic features, such as large tumors, follicular or Hürthle cell subtypes, extrathyroidal growth and distant metastases. Therefore, an optimal therapeutic approach is recommended. Current therapy includes a total thyroidectomy, if necessary combined with a lymph node dissection and followed by high dose radioiodine ablation. Radioiodine therapy in elderly patients meets specific problems, concerning thyroid hormone withdrawal, side effects of 131I and nursing problems. Additional treatment of residual, recurrent or metastatic disease must be tailored, according to the stage of the disease, and should not be denied on the basis of chronological age. Lifelong treatment with suppressive thyroid hormone therapy does not lead to important long-term side effects at old age.

Overexpression of p53 protein and MDM2 in papillary carcinomas of the thyroid: Correlations with clinicopathologic features

Expression of p53 protein and MDM2 was evaluated in paraffin-embedded tissue from 78 patients with papillary carcinomas of the thyroid (PCT), in order to elucidate the relationship between them and their correlations with some clinicopathologic features implicated in tumor progression. These proteins were expressed in nuclei of tumor cells, but not in non-tumor cells. Staining was defined as positive when 10% or more of tumor cells expressed these proteins. The number of cases positive for p53 protein was 21/78 (27%), and that positive for MDM2 was 26/78 (33%). Co-overexpression of p53 protein and MDM2 was observed in 12/78 cases (15%). A significant positive relationship was found between them (P < 0.01); p53-positive cases tended to be also positive for MDM2 and vice versa. Statistical analysis revealed that overexpression of p53 protein significantly correlated with large tumor size (P = 0.0271) and the presence of capsular invasion (P = 0.04). There were significant positive correlations between tumor size and intrathyroidal invasion and between tumor size and capsular invasion in PCT, suggesting that p53 protein overexpression is associated only with tumor progression (tumor size). However, we could not find any significant correlations between MDM2 expression and clinicopathologic features. Our findings suggest that overexpression of p53 protein and MDM2 in papillary carcinoma of the thyroid is associated with the progression of the tumors, and that p53 may be a marker of the progression of PCT.

Nuclear medicine imaging procedures in differentiated thyroid carcinoma patients with negative iodine scan

Radioiodine treatment following surgery is an effective therapy in differentiated thyroid carcinoma (DTC) patients. However, in DTC patients with metastases characterized by very low or absent iodine uptake, total thyroidectomy and radical loco-regional lymphoadenectomy is the only effective therapeutic approach. In the present article, we have discussed the most recently available nuclear medicine techniques utilized for the detection of DTC metastases that have lost the capacity to trap radioiodine. A review of the data published in the literature has been presented, and a comparative analysis made of the results obtained by other imaging modalities such as high resolution neck ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). In our experience, the most sensitive and accurate imaging procedure is represented by the combination of neck US and whole body 99mTc-methoxy-isobutylisonitrile (99mTc-MIBI) scintigraphy; this combination might be proposed as a first-line diagnostic approach in DTC patients with increased serum thyroglobulin (Tg) levels and negative high dose 131I scans.

Differentiated thyroid cancer: a retrospective analysis of 832 cases from Greece

OBJECTIVE

To analyse the initial manifestations, pathological findings, therapy, outcome and prognostic factors in patients with papillary and follicular carcinoma.

PATIENTS

832 patients with well differentiated thyroid carcinoma managed in our department during a period of 30 years (1965-1995). Follow-up data were available for 609 patients for a mean of 5.5 years (range 1-38 years), the remainder having been lost to follow-up.

RESULTS

The patients were 677 (81%) with papillary and 155 with follicular carcinoma. They were predominantly female (75%), presenting mainly with a single nodule (53%), while at the time of diagnosis 72% had intrathyroidal carcinomas (class I), 17% had nodal metastases (class II), 7% soft tissue invasion (class III) and 4% distant metastases (class IV). Fifty-five percent of the patients had a complete thyroidectomy (36% had a near total or total thyroidectomy and 19% near total or total thyroidectomy plus block dissection), 2.6% received external radiotherapy and 94% had radioactive iodine as part of the treatment of the original disease. Kaplan-Meier survival analysis was used to calculate both cancer related mortality and disease free survival in the patients followed-up. Although mortality (21 cancer-related deaths) was slightly higher for follicular than papillary carcinoma (10% vs. 5% and 16% vs. 10% in 10- and 15-year survival, respectively) the difference was not statistically significant. Extent of disease at diagnosis, male sex, tumour size and age > 60 years affected probability of cancer death. Cox's proportional hazard regression analysis for disease free survival showed that adverse independent prognostic factors were, for papillary carcinoma, male sex, class II or higher, tumour size > 1 cm and age > 60 years, while for follicular, class III or higher, size > 4 cm and age > 40 years.

CONCLUSIONS

We conclude that there is a higher prevalence of follicular carcinoma in our country probably due to a moderate degree of iodine deficiency still existing in Greece. Age and extent of disease at diagnosis were important prognostic factors affecting morbidity and mortality, whereas sex, tumour features and histological type were of minor importance. All these prognostic factors and their relative importance should be taken in consideration in the management of this disease.

External-beam radiation therapy in the treatment of differentiated thyroid cancer

The role of external-beam radiation therapy (EBRT) in differentiated thyroid cancer is reviewed. In the presence of gross residual disease after attempted surgical excision, retrospective series have reported local control is possible with EBRT. If, in addition to Iodine-131 (I131), there is a role for adjuvant EBRT in differentiated thyroid cancer, it would be only in patients in whom there is a high risk of relapse in the thyroid bed. Evidence is presented that suggests that EBRT can improve the local relapse-free rate in selected patients (over the age of 45, with microscopic residual disease or extensive extrathyroid invasion). For patients with recurrence in the thyroid bed, EBRT can be given in addition to surgery and I131. In bone metastases that are demonstrable radiographically, I131 therapy is often unsuccessful and EBRT also should be given. The technique of thyroid bed radiation is described. EBRT has acceptable acute toxicity and rarely produces serious long-term complications.

Differentiated thyroid cancer: determinants of disease progression in patients <21 years of age at diagnosis: a report from the Surgical Discipline Committee of the Children's Cancer Group

OBJECTIVE

This study was done to define the extent of disease and evaluate the effect of staging and treatment variables on progression-free survival in patients with differentiated thyroid carcinoma who were less than 21 years of age at diagnosis.

SUMMARY BACKGROUND DATA

Differentiated thyroid cancer in young patients is associated with early regional lymph node involvement and distant parenchymal metastases. Despite this, the overall long-term survival rate is greater than 90%, which suggests that biologic rather than treatment factors have a greater effect on outcome.

METHODS

Variables analyzed for their impact on progression-free survival in a multi-institutional cohort of 329 patients included age, antecedent thyroid irradiation, extrathyroidal tumor extension, size, nodal involvement, distant metastases, technique of thyroid surgery and lymphatic dissection, initial treatment with 131Iodine, residual cervical disease, and histopathologic subtype. Surgical complications were correlated with the specific procedures completed on the thyroid gland or cervical lymphatics.

RESULTS

The overall progression-free survival rate was 67% (95%, CI: 61%-73%) at 10 years with 2 disease-related deaths. Regional lymph node and distant metastases were present in 74% and 25% of patients, respectively. Progression-free survival was less in younger patients (p = 0.009) and those with residual cervical disease after thyroid surgery (p = 0.001). Permanent hypocalcemia was more frequent after total or subtotal thyroidectomy (p = 0.001) while wound complications increased after radical neck dissections (p < 0.00001).

CONCLUSIONS

The progression-free survival rate was better after a complete resection and in older patients. Progression-free survival rate was the same after lobectomy or more extensive thyroid procedures, but comparison was confounded by the increased use of total or subtotal thyroidectomy in patients with advanced disease. The risk of permanent hypocalcemia increased when total or subtotal thyroidectomy was done. Thyroid lobectomy alone may be appropriate for patients with small localized lesions while total or subtotal thyroidectomy should be considered for more extensive tumors.

Prognostic factors in papillary and follicular thyroid carcinomas: p53 expression is a significant indicator of prognosis

To identify clinical and histologic prognostic factors and to investigate whether immunohistochemical detection of p53 expression might contain prognostic information, a retrospective study of patient and tumor characteristics was performed in 225 cases of papillary and follicular thyroid carcinomas. The analyses were based on cause-specific and crude survival. In univariate analysis, age at diagnosis, tumor size, presence of distant metastases, histology (papillary contra follicular type), extrathyroidal invasion, necrosis in primary tumor, and p53 expression were significant prognostic indicators. For 211 patients (96%) all information was available and Cox's proportional hazard model was applied. The authors found that age, distant metastases, necrosis in primary tumor, extrathyroidal invasion, and p53 expression were significant prognostic factors. Analyses of cause-specific and crude survival gave similar results. The authors conclude that age at diagnosis, presence of distant metastases, necrosis in primary tumor, and extrathyroidal invasion are important prognostic factors, and that immunohistochemical detection of p53 protein in the primary tumor is a significant and independent prognostic indicator, which might be of value in the treatment planning in patients with papillary or follicular thyroid carcinomas.

Thyroid diseases in the elderly

The ageing thyroid is associated with a number of morphological and functional changes, such as decreased serum T3 and mean thyroid-stimulating hormone concentrations, that are to some extent independent of intercurrent non-thyroidal illnesses. All thyroid diseases, including clinical and subclinical hypo- and hyperthyroidism, non-toxic nodular goitre and thyroid cancer, are encountered in the elderly, but their prevalence and clinical expression differ from those observed in younger patients. In the elderly, autoimmune hypothyroidism is particularly prevalent, hyperthyroidism is mainly characterized by cardiovascular symptoms and is frequently due to toxic nodular goitres, and differentiated thyroid carcinoma is more aggressive. The interpretation of thyroid function tests is difficult in old individuals, because of age-associated changes in thyroid function and frequent alterations secondary to non-thyroidal illnesses and/or drugs. Treatment of thyroid disease deserves special attention in old patients because of the increased risk of complications.

Prognostic factors associated with differentiated thyroid cancer

A multivariate analysis was conducted on the survival data of 180 patients who underwent curative resection for differentiated thyroid cancer between 1966 and 1987, and the 10- and 20-year survival rates were found to be 80.6% and 73.1%, respectively. A survival analysis was also performed, testing the following factors: the patient's age at the time of diagnosis, tumor size, extraglandular extension, nodal status, distant metastases, operative procedure, sex, and histology. A univariate analysis found the initial six factors to be significant prognostic variables, but the latter two to be of no significance. On the other hand, the multivariate analysis showed that distant metastases, age, and tumor size were the most significant prognosticators. Thus, the age of the patient should be taken into consideration during the follow-up of treatment for differentiated thyroid cancer.

Classification of papillary cancer of the thyroid based on prognosis

Between 1965 and 1988 there were 2953 patients with papillary carcinoma treated at Noguchi Thyroid Clinic. Among them 761 patients were excluded because the primary tumor was < 10 mm in maximum diameter, the patient's age was > 80, or the patient underwent noncurative surgery. The remaining 2192 patients, 192 men and 2000 women, were analyzed. The mean follow-up period was 12.5 years. Total thyroidectomy, subtotal thyroidectomy, lobectomy with or without isthmectomy, and less than lobectomy were performed in 2.3%, 40.3%, 44.2%, and 13.2%, respectively. Modified radical neck dissection, partial node excision, and no node excision were performed in 77.8%, 6.4%, and 15.8%, respectively. Men and women were separately analyzed because their risk factors and prognosis were significantly different. Multivariate analysis was carried out according to Cox's regression hazard model. Independently significant factors affecting prognosis in men were aged and gross nodal metastasis; and age, gross nodal metastasis, tumor size, and number of adhered tissues or organs were the factors in women. Based on those risk factors patients were classified into three groups. For men, 65.6% were classified in the excellent group and their 10-year survival was 98.4%; 17.2% were classified as intermediate and 17.2% as poor with survival rates of 90.1% and 74.4%, respectively. For female patients 69.6% were classified in the excellent group, 18.6% in the intermediate group, and 11.9% in the poor group with 10-year survivals of 99.3%, 96.4%, and 88.8%, respectively.

Recurrence-associated mortality in patients with differentiated thyroid carcinoma

Differentiated thyroid carcinoma (DTC) is associated with prolonged natural history, and even recurrent tumor is not necessarily followed by increased mortality. Prognostic factors and different treatment strategies, therefore, are difficult to assess. One hundred and fifty-seven patients were followed in our clinic. In an attempt to predict mortality from this tumor, we evaluated the risk factors in 36 patients who presented with recurrent disease. Ten of these patients died. Age above 40 years at initial diagnosis was the predominant risk factor associated with 44% mortality after recurrence. Male sex, lack of radioiodine treatment, and distant site of initial recurrence were all associated with a trend towards increased mortality. Tumor histology and local invasion or extent of initial surgical treatment failed to affect mortality. In conclusion, this approach may be used to identify those patients who will die from their disease, despite currently available treatment. It remains to be seen, however, if new treatment protocols can be developed to improve the prognosis of these patients.

Thyroid cancer in children in Norway 1953-1987

All cases of thyroid cancer in children aged 15 years or younger registered in Norway (1953-1987) are presented. 30 girls and 5 boys are included, the youngest being a 6-year-old boy. Half of the patients were in the age-group 14-15 years. As for adults, papillary thyroid cancer was most common. 70% of the patients presented with tumour growth outside the thyroid gland. In spite of this, only 2 children died of the disease during the follow-time (maximum 37 years).

Management of local recurrence in well-differentiated thyroid carcinoma

Local recurrence of well-differentiated thyroid carcinoma has a reported mortality approaching 50%. The University of Kentucky experience was reviewed to determine whether aggressive surveillance and treatment with reoperation and/or I-131 ablation increased survival following recurrence. Records of 66 consecutive patients with well-differentiated thyroid carcinoma treated at the University of Kentucky Medical Center (1980-1989) were reviewed. Forty-nine cases of papillary carcinoma and 17 cases of follicular carcinoma were studied; median follow-up was 68 months. At presentation, patients with follicular carcinoma were older (48 versus 35 years; P less than 0.05) and more frequently had metastatic disease (17% versus 2%, P less than 0.05). Fifty-eight (88%) patients were alive and disease-free at last follow-up. Fifteen patients (24%) had developed recurrent disease; median time to recurrence was 24 months. Multivariate regression examined the variables of age, sex, histology, tumor size, cervical adenopathy, capsular and vascular invasion, multicentricity, and surgical procedure. While distant metastases affected actuarial survival, no factor independently predicted local recurrence. In six patients with local recurrence, nonpalpable disease was detected by I-131 scan. All were treated with ablation and remain disease-free (mean follow-up 42 months). Eight patients with local recurrence presented with palpable lesions; seven underwent surgery. While two patients developed repeated local recurrences, the other five remain disease-free (mean follow-up 52 months). Early detection and aggressive treatment of local recurrence improve survival in patients with well-differentiated thyroid carcinoma. To facilitate use of I-131, we advise total thyroidectomy for patients with well-differentiated thyroid carcinoma.

Trends in thyroid cancer incidence in Sweden, 1958-1981, by histopathologic type

Time trends in the incidence of malignant neoplasms of the thyroid were examined for Sweden for the period 1958-81, 5,838 cases being studied. Autopsy-diagnosed cases were excluded. Mean annual changes in the age-standardized rates over this period were 1.9% and 1.2% for women and men, respectively, for all thyroid carcinomas combined; 4.9% and 2.1% for papillary carcinoma; 0.9% and 2.1% for follicular carcinoma; and -1.0% and -2.1% for anaplastic carcinoma. Age, period and cohort models were fitted. There was a progressive increase in papillary cancer incidence for cohorts born since 1919. This increase cannot be satisfactorily explained as an artefact of trends in classification, and probably reflects a real increase in incidence. A less marked increase was seen for follicular cancer, and there was a decline for cohorts born since 1939. While the risk of papillary and anaplastic carcinoma was lower in iodine-deficient areas, follicular cancer risk was twice as high in these areas, for men only. There was a steady decline of anaplastic cancer in both sexes after 1965, largely attributable to a decline in cohorts born since 1924.

Previous thyroid disease and risk of thyroid cancer in Switzerland

A hospital-based case-control study of 86 cases of thyroid cancer and 317 controls was done in the Swiss Canton of Vaud. Patients with thyroid cancer tended to be better educated (odds ratio [OR] 2.1 for greater than or equal to 14 vs. less than or equal to 8 years of education 95% CI 1.1-4.1) and of higher social class than controls. Cases more often had a history of benign thyroid nodules (OR 25.2, 95% CI 7.6-83.6) and non-toxic goitre (OR 5.3, 95% CI 2.5-11.2). Furthermore, patients with thyroid cancer were more likely to have resided in endemic goitre areas (OR 1.7, 95% CI 1.0-3.0) and to have had first-degree relatives affected by benign thyroid disease (OR 3.9, 95% CI 2.1-7.1). Therefore, this study offers quantitative evidence of the association between various thyroid diseases and the risk of thyroid cancer which, despite difficulties in the classification of benign and malignant thyroid diseases, is remarkably consistent in studies from different countries.

Descriptive epidemiology of thyroid cancer in the Swiss Canton of Vaud

Although substantial decreases have been recorded, age-standardized mortality rates from thyroid cancer in Switzerland are still the highest in Europe in men (0.9/100,000), together with those from Austria, and the third highest (1.0/100,000) in women. Detailed analysis of 308 new cases registered between 1974 and 1987 in the Swiss Canton of Vaud revealed an overall incidence rate of 1.36/100,000 men (world standard) in 1974-1980 and of 1.74/100,000 in 1981-1987. Corresponding values for women were 4.28 and 4.51, respectively. Thus, women constituted the majority of all cases (76%). Papillary carcinoma was the most frequent histological type (53%) followed by follicular (27%), undifferentiated (5%) and medullary (2%); other morphologies and clinical tumours accounted for 13% of the whole series. In both sexes, most of the apparent increase over the calendar period was restricted to the papillary type. Overall 5- and 10-year survival rates were 71% and 57%. When various factors were introduced in a Cox proportional-hazard model, young age at diagnosis (hazard rate for greater than or equal to 65 years vs less than 45 = 14.7; 95% confidence interval = 7.5-29.1) and good histological differentiation (hazard rate for papillary and follicular vs undifferentiated = 0.4) emerged as strong favourable and independent prognostic factors. The reduced hazard rate for women, other factors being equal, was of borderline significance (0.7, 95% confidence interval = 0.5-1.0), whereas no significant difference was observed between follicular and papillary carcinomas, and calendar periods of diagnosis.