Multivariate analysis of risk factors influencing survival in 110 ethnic Chinese with papillary thyroid cancer

Warthin-like variant of papillary thyroid carcinoma: single institution experience

BACKGROUND

Correct diagnosis of the variants of papillary thyroid carcinoma (PTC) is important because these variants differ in clinical course. The Warthin-like variant (WLV) is relatively uncommon and is recognized as not different from conventional PTC. We therefore assessed the clinicopathological features of patients with WLV of PTC who were diagnosed and treated at our institution.

METHODS

Of the 8179 patients treated for PTC at the Thyroid Cancer Center, Gangnam Severance Hospital, Yonsei University College of Medicine, between January 2007 and December 2012, 16 patients (0.2%) were pathologically diagnosed with WLV of PTC. Their clinicopathological features and post-operative follow-up for local recurrence and distant metastasis were retrospectively investigated.

RESULT

Mean patient age was 44.9 years (range: 23-61 years), with seven (44%) being younger than 45 years. Only one of the 16 patients was male (6%). Mean tumour size was 8.9 mm (range: 3-22 mm). Extrathyroidal extension was observed in seven patients (44%), associated thyroiditis in 11 (69%) and lymph node metastasis in six (38%). The mean follow-up period was 37 months (range: 13-78 months), during which none of the 16 patients experienced recurrence or metastasis. Fifteen patients (94%) had MACIS score <6, with the remaining patient having a MACIS score of 6.33.

CONCLUSION

WLV of PTC is rare, with favourable prognosis. Nevertheless, it is important to determine the histopathological features of these tumours.

Insular thyroid carcinoma: a retrospective clinicopathologic study

BACKGROUND

Poorly differentiated carcinoma is a rare epithelial tumor that falls between well-differentiated thyroid carcinoma and anaplastic thyroid carcinoma in terms of morphologic appearance and biologic behavior. An insular variant was characterized in 1983. Further study of this neoplasm is warranted owing to its high aggressiveness, propensity to local recurrence and distant metastases, and high associated mortality. Since insular thyroid carcinoma may have varied presentations, treatment should be individualized.

PURPOSE

To describe the experience of a major tertiary medical center with insular thyroid carcinoma over a 7-year period.

MATERIAL AND METHODS

The study sample consisted of 17 patients with poorly differentiated thyroid cancer, insular variant, who were treated and followed at the Department of Otolaryngology, Head and Neck Surgery of Rabin Medical Center, Israel, in 1992-2009. The medical files were reviewed for background data, clinicopathologic features, treatment, and outcome.

RESULTS

The study group included 10 men and 7 women with a mean age of 63 years (range 16-78). Initial treatment was total thyroidectomy, in a single session (n=9) or two sessions (n=8), followed by radioiodine ablation. In addition, five patients received postoperative external beam radiation and one patient received chemotherapy. Nine patients had extrathyroidal extension, seven had vascular invasion, and four had multifocal disease. Distant metastases were present in four patients. Follow-up ranged from 6 months to 12 years. At present, 11 patients are alive and well. Five died of disease, and one died of another cause.

CONCLUSION

Insular thyroid carcinoma is aggressive and difficult to treat. Surgery remains the mainstay of treatment, though multimodality therapy is usually required.

Insular variant of poorly differentiated thyroid carcinoma

OBJECTIVE

To present a case of an insular variant of poorly differentiated thyroid carcinoma (PDTC) and to review the literature related to diagnosis, natural history, and treatment of this unusual form of thyroid cancer.

METHODS

We present the clinical, laboratory, and pathologic findings of the study patient and review English-language literature related to PDTC published between 1970 and the present.

RESULTS

PDTC is a controversial and rare epithelial thyroid cancer, intermediate between differentiated thyroid carcinoma and anaplastic thyroid carcinoma that exhibits increased aggressiveness, propensity to local recurrence, distant metastases, and increased mortality. PDTC warrants aggressive management with total thyroidectomy followed by radioactive iodine ablation and potentially additional therapy for residual or recurrent disease. Some carcinomas do not take up radioactive iodine, and dedifferentiated clones of distant metastases may evolve. It is unclear whether chemotherapy is beneficial. Use of additional imaging modalities, including positron emission tomography, 18-fludeoxyglucose positron emission tomography/computed tomography, 18-fludeoxyglucose positron emission tomography/computed tomography/magnetic resonance imaging, (124)I positron emission tomography/computed tomography, positron emission tomography/magnetic resonance imaging fusion studies, and recombinant human thyrotropin-stimulated radioactive iodine uptake for cancer surveillance are discussed.

CONCLUSIONS

PDTC is an unusual and aggressive form of thyroid cancer. Fine-needle aspiration cytology may not yield sufficient information to specifically diagnose PDTC. Aggressive management with total thyroidectomy and neck dissection followed by high-dose radioactive iodine remnant ablation is standard. Iodine I 131 whole body scanning is often the initial test for tumor surveillance, with other imaging modalities applied as needed.

Thyroid surgery in the tropics

In the tropics thyroid surgery is carried out either by general surgeons or ear, nose and throat surgeons and there are few places with a subspecialist endocrine or head and neck surgeon. The aim of this review is to determine the pattern of thyroid pathology, surgery and surgical outcomes in the tropics. A review of thyroid surgery in tropical regions was carried out based on published articles in English in Medline (1965-2004). The findings are also discussed in the light of the authors' own experience of thyroid disease and thyroid surgery in four continents. The pattern of thyroid pathology varies in the tropics, particularly in regions where endemic goitre is common. Endemic goitre usually regresses with iodine therapy. There is a rising incidence of thyroid autoimmune disease, particularly Graves' disease and Hashimoto's thyroiditis, probably related to an environmental immunological stimulus associated with development. Surgery is indicated for the same reasons as in the developed countries: thyrotoxicosis (more often in the absence of radioactive iodine therapy), solitary thyroid nodule and multinodular or malignant goitre. However, a preoperative cytological diagnosis will only be available in important centres where there is a pathologist. Malignancy appears more prevalent in nodules and goitres in the tropics than in the developed countries, perhaps because patients with malignancy are more likely to be referred to a surgeon. Nonetheless, the evidence suggests that thyroid surgery can be carried out safely with a minimum of complications even in remote mission hospitals with limited facilities for investigation. Standards can be set in terms of surgical outcomes; for example, mortality (0%), permanent recurrent laryngeal nerve (RLN) injury (<2%), re-exploration for haematoma(<2%), permanent hypocalcaemia (<5%) and wound infection (2.5%). The choice of operation depends on the local pathology and the likelihood of being able to obtain lifelong thyroxine. Total thyroidectomy should be avoided whenever possible if thyroxine supplies are unreliable. Advanced thyroid cancer presents a therapeutic challenge and some cases will be unresectable. The management options are limited by the resources available. Similar surgical outcomes should be able to be achieved no matter where the surgery is carried out.

Staging systems for papillary thyroid carcinoma: a study of 2 tertiary referral centers

OBJECTIVE

To find out the most applicable and consistent staging system for papillary thyroid carcinoma (PTC) available in the literature.

BACKGROUND

The commonly used staging systems for PTC have predicted cancer-specific survival (CSS) well. However, their applicability and generalizability have not yet been evaluated in different clinical settings.

METHODS

A MEDLINE search from 1965 to 2005 was carried out to identify different staging systems available in the literature and 9 systems were applicable to 1634 PTC patients within 2 tertiary-referral centers. The CSS of each staging system within individual centers were calculated using Kaplan-Meier method and the CSS of each tumor stage in one individual center was compared with that of the other by log-rank test. In addition, within each center, the predictability of each staging system relative to the others was ranked based on the proportion of variation explained (PVE) value.

RESULTS

Clinicopathologic features, treatment received, and tumor stages were significantly different between the 2 centers. There were also significant differences in CSS within at least one tumor stage between the 2 centers in 8 of the 9 staging systems. The TNM was a highly predictive and consistent staging system within the 2 centers. Although the absolute PVE values differed between the 2 centers, the relative ranking of the 9 staging systems within each center correlated significantly to each other (P < 0.05).

CONCLUSIONS

Despite referral, treatment, and data collection biases inherent within each center, the TNM system remained to be the most applicable and consistent staging system for PTC in 2 centers managing the same population group.

Diffuse Sclerosing Variant of Papillary Carcinoma of the Thyroid: A 35-Year Comparative Study at a Single Institution

BACKGROUND

Diffuse sclerosing variant (DSV) is a rare variant of papillary thyroid carcinoma (PTC), and the features of this carcinoma have not been fully characterized. The aim of this study was to analyze the clinicopathologic features of a large cohort of patients with this disease.

METHODS

We reclassified primary thyroid carcinomas treated in a 35-year study period and studied the clinicopathologic features and outcomes of DSV of PTC in comparison with classic PTC.

RESULTS

Fifteen patients (2 men and 13 women) with DSV of PTC were identified who had surgical resection of the thyroid. Fine-needle aspiration biopsy diagnosed 83% (10 of 12) of the tumors. Compared with classic PTC, patients with DSV presented at a younger age (mean age, 29 vs. 46 years; P = .0001), had larger tumors (mean diameter, 3.6 vs. 2.2 cm; P = .002), and had a higher incidence of cervical nodal metastases (80% vs. 43%; P = .006). Ten patients had received postoperative iodine 131 ablation, and four had also received external-beam irradiation. Distant metastases were detected in two patients (one in lung and one in brain). One third (5 of 15) of the patients developed disease recurrence. Lymph node recurrence was detected in one patient 12 years after the initial operation. Over a median follow-up period of 10.7 years, one patient with an initial incomplete excision died of the carcinoma. The overall disease-specific survival rate was 93%.

CONCLUSIONS

DSV of PTC had distinctive clinicopathologic features and a high incidence of recurrence after operation but had a prognosis similar to that of classic PTC.

Recurrent laryngeal nerve palsy in well-differentiated thyroid carcinoma: clinicopathologic features and outcome study

Involvement of the recurrent laryngeal nerve (RLN) by well-differentiated thyroid carcinoma may not invariably lead to unilateral cord palsy, although the presence of RLN palsy is associated with locally advanced disease. The present study evaluates the clinicopathologic features and outcomes of patients surgically treated for well-differentiated thyroid carcinoma with documented nonfunctioning RLN at presentation. From 1970 to 2002, 20 of 709 patients undergoing surgical treatment for well-differentiated thyroid carcinoma were found to have ipsilateral unilateral cord palsy by routine preoperative laryngoscopy. There were 5 men and 15 women with a median age of 70 years. Nine patients (45%) did not have a clinically palpable thyroid mass, and hoarseness was the primary presenting symptom. All patients had histologically confirmed pT4 papillary thyroid carcinoma with a median size of 4 cm. Cervical nodal and pulmonary metastases were detected in 14 (70%) and 2 (10%) patients, respectively. The ipsilateral recurrent nerve was transected in all patients because of gross tumor involvement, and 19 patients underwent total or completion total thyroidectomy. Resection was incomplete in 15 patients, including 2 who underwent a debulking procedure and required reoperation for local control. Postoperative radioactive iodine ablation and external-beam irradiation were administered to 18 and 13 patients, respectively. Over a median follow-up of 4.5 years, 10 patients survived without evidence of recurrence, 5 died of disease recurrence, and 5 died of unrelated causes. The 5-year and 10-year cause-specific mortality was 17% and 42%, respectively. Patients developing distant metastasis at presentation or during follow-up had a significantly increased cause-specific mortality (p = 0.002). Preoperative RLN palsy can be the first symptom in patients with locally advanced papillary thyroid carcinoma. Despite the adoption of a relatively conservative surgical treatment, long-term survival can be achieved in selected patients.

Optimizing the treatment of AMES high-risk papillary thyroid carcinoma

A minority of patients with papillary thyroid carcinoma (PTC) is at high-risk of developing recurrent disease and death. Risk group stratification as defined by age, metastases to distant site, extrathyroidal invasion, and tumor size (AMES) criteria is frequently employed to identify high-risk patients for aggressive surgical and adjuvant treatments. The present study aimed at evaluating risk factors and the impact of treatment on cause-specific mortality (CSM) in this group of high-risk patients. From 1961 to 2000,150 of 499 patients surgically treated for PTC were considered as high-risk by AMES criteria. At 10-years CSM was significantly higher in high-risk patients (28%) than in low-risk patients (2%) (p < 0.0001). The clinicopathologic features, treatment, and outcome of AMES high-risk patients were retrospectively studied and risk factors for CSM were analyzed. There were 58 men and 92 women with a median age of 62 years (range: 18-87 years). Bilateral thyroidectomy was performed for 143 (95%) patients and concomitant neck dissection was performed for 82 patients (55%). Thirty-six patients (24%) underwent incomplete tumor excision with residual disease. Radioactive iodine (I131) ablation and external-beam irradiation were administered to 102 (68%) and 46 patients (31%), respectively. Over a median follow-up of 7.6 years, the overall mortality was 23% and 44%, whereas the CSM was 14% and 28% at 5 and 10 years, respectively. Using the Cox proportional hazard model, distant metastasis at presentation, incomplete tumor excision, and no postoperative I131 treatment were independent prognostic factors of poor survival. Patients who underwent an incomplete excision showed improved survival after I131 ablation (p = 0.0008), external-beam irradiation (p = 0.02), or both forms of treatment (p = 0.04). Within this high-risk AMES group, International Union Against Cancer (UICC) pTNM staging and MACIS (Metastasis, Age, Completeness, Invasion, Size) scoring correlated significantly with CSM. AMES high-risk PTC patients should undergo total thyroidectomy aiming at complete tumor resection followed by I131 ablation. External-beam irradiation should be added for patients with residual disease after an incomplete excision.

Prognostic significance of magnetic resonance findings in advanced papillary thyroid cancer

We assessed the prognostic importance of magnetic resonance (MR) findings in locally advanced papillary thyroid cancer. MR findings, clinical data, and pathologic (and surgical) data for 66 patients, including 51 women and 15 men with a mean age of 57 years, who had primary surgery for papillary thyroid cancers were correlated with prognosis. Mean follow-up was 27.5 months (range, 5-117 months). Recurrence was seen in 18 patients (27%). In univariate analyses, age of 60 years or more (p = 0.0066), male gender (p = 0.0373), six MR findings (tumor size of > or = 4 cm ([p = 0.0002], ill-defined margins ([p < 0.0001], tumor extension of the trachea [p = 0.0337], carotoid artery [p = 0.0028]), esophagus [p < 0.0001], and lymph nodes [p = 0.0005]), and three pathologic findings (tumor extension of soft tissues [p = 0.0288], carotid artery [p = 0.0013], and esophagus [p < 0.0001]) had a significant adverse effect on disease-free survival. In multivariate analyses, tumor size (p = 0.0169) and nodal metastasis (p = 0.0393) determined on MR imaging and pathologic esophageal invasion (p = 0.0016) were the only significant independent variables. Esophageal invasion was accurately diagnosed with MR imaging (94% accuracy). MR findings may contain prognostic importance of locally advanced papillary thyroid cancer.

Insular and anaplastic carcinoma of the thyroid: a 45-year comparative study at a single institution and a review of the significance of p53 and p21

OBJECTIVE

To analyze the clinicopathologic features of a large cohort of patients with insular or anaplastic carcinomas treated at a single institution.

SUMMARY BACKGROUND DATA

Insular and anaplastic carcinomas of the thyroid, although uncommon, have more aggressive clinical behavior than well-differentiated carcinomas of the thyroid. In the literature, the incidence and features of these carcinomas have not been fully characterized.

METHODS

The authors reclassified 740 primary thyroid carcinomas diagnosed and treated between January 1, 1954, and December 30, 1998, to select those with features that met the histologic criteria of insular or anaplastic carcinoma. The clinicopathologic features of these carcinomas were studied and compared. The expression of p53 and p21 in these tumors was analyzed by immunohistochemistry.

RESULTS

Twenty-two patients (5 men, 17 women) with insular carcinoma and 38 patients (7 men, 31 women) with anaplastic carcinoma were found. Patients with insular carcinomas were younger (mean age 45 vs. 70 years) and had smaller tumors than those with anaplastic carcinomas (mean diameter 5 vs. 8 cm). Insular carcinomas were commonly mislabeled as other histologic subtypes, whereas anaplastic carcinomas might be overdiagnosed on pathologic examination. A history of longstanding goiter (>10 years) was noted in 27% of patients with insular carcinoma and 24% of patients with anaplastic carcinomas. Concomitant well-differentiated carcinomas of the thyroid were noted in 59% of patients with insular carcinoma and 39% of patients with anaplastic carcinoma. In anaplastic carcinomas, 13% of patients had concomitant insular carcinoma. Calcification or bone was noted in the stroma of 23% of patients with insular carcinomas and 47% of those with anaplastic carcinomas. The 10-year survival rates for patients with insular carcinoma and anaplastic carcinoma were 42% and 3%, respectively. Distant metastases were seen in 32% of patients with insular carcinoma and in 47% of patients with anaplastic carcinomas. In both types of carcinomas, metastatic tumors were often seen in bone and lung. Distant metastases were noted in a variety of organs in anaplastic carcinomas. In insular carcinoma, neither p53 nor p21 expression was present. In anaplastic carcinoma, p53 and p21 expression was identified in 69% and 3%, respectively. Concomitant expression of p53 and p21 was noted in one tumor.

CONCLUSIONS

Insular carcinoma and anaplastic carcinoma had distinctive clinicopathologic features, and recognition of these histologic variants is important for better management of these tumors in the future. p53 overexpression might have a role in dedifferentiation from insular carcinoma to anaplastic carcinoma.

Incidence and clinical characteristics of thyroid carcinoma after iodine prophylaxis in an endemic goiter country

Iodized salt prophylaxis has been performed in Austria since 1963. Through this approach, mean urinary iodine excretion has been normalized to 144+/-23.5 microg/g creatinine per day. Thus Tyrol is no longer an endemic goiter area. We have analyzed the impact of iodized salt prophylaxis on thyroid cancer (TC) comparing data from the early 1960s with those corresponding to the period 1986 to 1995, when iodine supply was normalized. The study included 439 patients from Tyrol and Southern Tyrol. The incidence of TC in Tyrol has risen during the past decades from 3.07 between in 1957 and 1970 to 7.8 between 1990 and 1994 (CR/100000/year). We observed a rise in the percentage of differentiated adenocarcinomas (56% to 91.5%) with a predominance of papillary TC (54.4%) along with a decrease of anaplastic TC. In addition to these histological features, a shift to less advanced TNM stages, eg, T1-3, N0-1a, M0, was obvious, increasing from 29% to 72.2%, whereas advanced tumors, ie, T4 or N1b or M1, decreased from 71% to 28%. These changes have significantly improved prognosis. The current 5-year survival rate is 90.7% as compared with a rate of 73% in the 1960s; the values for 7-year survival are 89% and 48%, respectively. The marked effects of age, tumor stages, and histology on prognosis were confirmed with the Kaplan-Meier method. We conclude that together with normalization of iodine supply in an endemic goiter region the epidemiological profile of TC has changed. Even though the incidence of TC has risen, prognosis has significantly improved due to a shift towards differentiated forms of TC that are diagnosed at earlier stages.