Distant metastases in differentiated thyroid carcinomas: a clinical and pathologic study

Prognostic factors in differentiated thyroid carcinoma: a multivariate analysis of 234 consecutive patients

BACKGROUND AND OBJECTIVES

The clinical characteristics and patient outcome of a group of patients treated for differentiated thyroid carcinoma (DTC) were analyzed in order to assess the relative influence of different prognostic factors.

MATERIALS AND METHODS

We retrospectively reviewed data about sex, age, size and histologic behavior of the tumor, extrathyroid extension of the tumor, lymph node status, distant metastasis at diagnosis, surgical procedures, and overall survival from 234 patients treated for DTC. Data were submitted to a statistical analysis.

RESULTS

Using a univariate analysis, we found that survival rates were significantly influenced by age (P = 0.0001), size (P = 0.018), extrathyroidal extension (P = 0.000001), lymph node involvement (P = 0.03), and distant metastases (P = 0.049). Age and size were independent prognostic factors at multivariate analysis (t = 2.694 and t = 2.443, respectively).

CONCLUSIONS

On the basis of our results and of a review of the literature, we conclude that total thyroidectomy is the treatment of choice in DTC, except for small (<1 cm) papillary carcinoma, that could be treated by lobectomy plus isthmectomy, while lymphadenectomy is indicated only in case of macroscopic involvement.

Therapeutic strategies and long-term results in differentiated thyroid cancer

Differentiated thyroid carcinoma (DTC) is usually an indolent tumor associated with a low mortality. However, DTC, particularly papillary thyroid carcinoma, happens to be a multicentric tumor and tends to spread to the regional lymph nodes in the early stage of the disease; some patients with DTC do die from metastatic or recurrent disease. Despite the small number of these patients, therapeutic strategies designed to prevent such outcomes should be pursued. In this review, we attempt to evaluate the impact of different therapeutic strategies on survival and recurrence. Consequently, we conclude that the surgical approach to DIC should be individualized on the basis of the biologic behavior of the tumor, rather than on the extent of cancer involvement in the thyroid and regional lymph nodes. It is mandatory to expand our efforts to identify high-risk patients more accurately, thereby facilitating more rational approaches to treatment.

Metastasis to the liver in well-differentiated carcinoma of the thyroid

Eleven patients (6 women; 5 men) of a series of 1,916 developed liver metastasis from differentiated thyroid cancer within 3 months to 202 months after the initial diagnosis. Liver metastasis generally appeared after the onset of metastases at other sites. The metastasis to the liver was clinically suspected in 8 patients whereas it was accidentally diagnosed on ultrasound examination of abdomen for a complaint of back pain in 1 patient, on a whole body diagnostic radioiodine scan in 1 case, and on radionuclide liver scan in 1 patient. Three patients had noniodide concentrating hepatic metastasis which were treated with chemotherapy but with poor response. The remaining 8 patients were treated with radioiodine. The survival rate was poor but could not be attributed to liver metastasis per se because of the extensive metastatic disease at other sites.

Tall cell variant of papillary thyroid carcinoma: a reassessment and immunohistochemical study with comparison to the usual type of papillary carcinoma of the thyroid

A review of 92 consecutive cases of papillary thyroid carcinoma diagnosed at The Methodist Hospital revealed 11 tall cell variant (TCV) cases in nine women and two men. There was a greater average age and larger tumor diameter of TCV cases compared with papillary thyroid carcinoma of the usual type (UPTC), but these differences were not statistically significant. Extrathyroidal extension of tumor was noted in nine of 11 TCV cases and was intraoperatively evident in five cases. The presence of extrathyroidal extension represented a statistically significant difference between TCV and UPTC (p = 0.0001) in a multivariate stepwise logistic regression analysis, with controls for variables of age, sex, tumor size, and lymph node metastases. In 11 TCV patients, tumor recurrence was present in two cases, and there was one tumor-associated death with 1 to 4 years of follow-up. Immunohistochemical stains for thyroglobulin, vimentin, keratins, and Leu-7 were positive in all TCV cases and in 16 of 16 UPTC. Immunoreactivity with antibodies to Leu M1 antigen, a myelomonocytic marker included in cluster designation group (CD 15), which is present in many adenocarcinomas, was present diffusely in all TCV, in contrast to UPTC (with sparse immunostaining in only one of 16 cases). Immunoreactivity with antibodies to ZC-23, an anti-carcinoembryonic antigen (CEA) monoclonal antibody with cross-reactivity to nonspecific cross-reacting antigen and biliary glycoprotein antigen, was present in all TCV but was not present in UPTC. COL-1, a CEA-specific monoclonal antibody, was nonimmunoreactive with all TCV and UPTC cases. Epithelial membrane antigen (EMA) was present in all TCV but was also present focally in eight of 16 UPTC, sometimes in a membranous pattern in epithelium surrounding cystic or hemorrhagic spaces. Strong immunoreactivity with antibodies to Leu M1 and EMA in papillary carcinomas of the thyroid has been associated with advanced stages of disease and tumor-associated mortality. The pattern of immunoreactivity in TCV is dissimilar to that in UPTC and is supportive evidence that TCV is a neoplasm that is distinct from papillary thyroid carcinoma of the usual type.

Poorly differentiated ('insular') carcinoma of the thyroid

Three cases of unusual poorly differentiated ('insular') carcinoma of the thyroid gland are presented. These three thyroid carcinomas were large; the tumors from patients 1 and 3 were encapsulated, and that from patient 2 showed invasive growth. Microscopically the tumors were characterized by well-defined solid nests (insulae), which were composed of rather small and uniform tumor cells with round to oval nuclei. Formation of small and colloid-containing follicles was associated with these nests to varying degrees. The tumors of patients 1 and 3 were composed entirely of insular components, but that of patient 2 was associated with small areas of well-differentiated follicular carcinoma. The metastatic tumors of patients 1 and 2 were essentially similar to the primary with small foci of follicular carcinoma. Patient 1 is alive with local and mediastinal node recurrences, but patient 2 died of the disease with local recurrences and metastases to lungs, bones and skin. Patient 3 had no recurrences and died of unrelated disease 5 years after surgery. The present study indicates that insular carcinomas have characteristic histologic features and a less favorable prognosis, confirming the findings of previous studies.

Resection of metastatic thyroid carcinomas to the liver and the kidney: report of a case

Differentiated thyroid cancer is considered to have a quite favorable prognosis. However, some patients die as a result of distant metastasis, which mainly consists of pulmonary, mediastinal, or osteal metastases. The biological features of the tumor, such as a slow growth gradient, indicate the possibility of achieving comparatively satisfactory results in the treatment of such distant metastases. A complete surgical excision of the distant metastases in differentiated thyroid carcinoma has been reported to offer the best chance for prolonged survival. A case of unusual metastasis sites on the caudate lobe of the liver and right kidney occurring in a 72-year-old woman is herein presented. The location of the surgically treated distant metastases of the papillary thyroid carcinoma make this case unique.

Aberrations of growth factor control in metastatic follicular thyroid cancer in vitro

The aggressiveness of follicular thyroid cancer (FTC) varies widely, and metastasis is the primary cause of death. Uncontrolled proliferation of cancer cells may be associated with loss of growth factor control. We investigated the effects of stimulating (epidermal growth factor [EGF]; thyreotropin [TSH] in low concentrations) and inhibiting growth factors (transforming growth factor beta 1 [TGF beta 1]; TSH in high concentrations) on invasion and growth of FTC cell lines from the thyroid tumor (FTC133) and from the lymph node (FTC236) and lung (FTC238) metastases of the same patient. Invasion-penetration through an 8 microns pore membrane, covered by Matrigel (basement membrane)-and growth were measured using the MTT-method. EGF (10 ng/ml) and TSH in low concentrations (1 mU/ml) stimulated invasion and growth of all FTC cell lines, but the amplitude of stimulation differed significantly. The parental cell line FTC133 was considerably more responsive to growth factor stimulation than the metastatic clones. Invasion of FTC133 was enhanced by 42% (EGF; p < 0.02) and 21% (TSH; p < 0.01), invasion of FTC236 by 8% (EGF; p < 0.02) and 8% (TSH; p < 0.01), and invasion of FTC238 by 9% (EGF; p < 0.02) and 8% (TSH; p < 0.01). Conversely, invasion and growth of FTC133 were significantly more inhibited by TGF beta 1 (10 ng/ml) and supraphysiologic concentrations of TSH (100 mU/ml) than the cell lines from the lymph node and lung metastases. At day 7, invasion of FTC133 was inhibited by 32% (TGF beta 1; p < 0.02) and 21% (TSH; p < 0.01), invasion of FTC236 by 18% (TGF beta 1; p < 0.02) and 11% (TSH; p < 0.01), and invasion of FTC238 by 16% (TGF beta 1; p < 0.02) and 12% (TSH; p < 0.01). Moreover, we analyzed growth factor independence in minimally supplemented or unsupplemented medium. Growth, but no invasion was evident when cells were cultured completely unsupplemented over 7 days. These results suggest that metastatic FTCs may have developed by escaping from the normal control of TSH and other growth factors.

Management of patients with differentiated thyroid cancer who have positive serum thyroglobulin levels and negative radioiodine scans

Most current evidence suggests that patients with papillary or follicular thyroid cancer after total thyroidectomy who are Tg positive (Tg > or = 10 ng/mL) and radioactive iodine scan negative warrant treatment with 100 mCi of 131I with a follow up scan and Tg determination. If isolated focal metastatic deposits are present they should be resected before treatment with radioiodine. Although some physicians might recommend radioiodine treatment only for high risk patients, we would recommend it for all patients with elevated serum Tg levels that increase after TSH stimulation, or until further information becomes available to support a different approach.

Surgical reintervention for differentiated thyroid cancer

Reoperation was performed in 110 of 185 patients with a differentiated thyroid carcinoma. In 25 patients (23 per cent) the indication for reintervention was a large thyroid remnant and in the other 85 (77 per cent) persistent or recurrent cancer was suspected. In 32 (29 per cent) of the 110 patients undergoing reoperation no evidence of cancer tissue was found. Tumour tissue in 33 patients (30 per cent) was resectable. Of 45 patients (41 per cent) with residual tumour after operation 24 showed only occult thyroid carcinoma with a raised serum thyroglobulin level. Eight of 21 patients with macroscopically persistent tumour died from the disease during a mean follow-up of 2.3 years. In 13 of 38 patients the investigated recurrent tumours were histologically less differentiated than the primary lesions, stressing the importance of total tumour clearance. The treatment of choice for persistent and recurrent differentiated thyroid carcinoma is surgical reintervention, if feasible, before radioiodine and radiation therapy are considered.

An immunohistochemical study of epithelial membrane antigen, cytokeratin, and vimentin in papillary thyroid carcinoma. Recognition of lethal and favorable prognostic types

METHODS

Immunoreactivity for epithelial membrane antigen (EMA), cytokeratin, and vimentin was investigated in 15 papillary thyroid carcinomas (PTC) with distant metastases, 25 PTC without distant metastases, and 34 occult PTC without distant metastases that were found incidentally at autopsy.

RESULTS

More than 50% of the tumor cells were positive for EMA in 7 (47%) of 15 PTC with distant metastases, 0 (0%) of 25 PTC without distant metastases, and 1 (3%) of 34 occult PTC. The incidence of EMA positivity in PTC with distant metastases was significantly different from that of both PTC without distant metastases and occult PTC (P < 0.001). Cytokeratin reactivity was similar in the three groups, and almost all PTC stained strongly for cytokeratin. Concerning vimentin positivity, there were no significant differences in three groups; however, PTC with distant metastases tended to stain more weakly or focally than PTC without distant metastases or occult PTC.

CONCLUSIONS

These results suggest that EMA reactivity may be a useful factor for anticipating the individual risk of distant metastasis or death from PTC at the time of initial surgical treatment.

Papillary thyroid carcinoma in Kanazawa, Japan: prognostic significance of histological subtypes

A retrospective analysis of 183 papillary thyroid carcinomas was made in order to assess the prognostic factors related to survival. The following factors were found to adversely affect the prognosis: trabecular subtype of papillary carcinoma, the extent of the primary tumour, regional lymph node involvement, the presence of distant metastases, old age, male sex and the extent of the neck dissection. The presence of the follicular variant of papillary carcinoma and the extent of the thyroidectomy did not influence the prognosis. The trabecular subtype of papillary carcinoma is characterized by a trabecular or solid arrangement of follicular cells with nuclei of ground-glass appearance. Univariate and multivariate analysis indicated that patients with this type of thyroid tumour had a poorer prognosis than those with the well-differentiated or follicular variants of papillary carcinoma. In our opinion the trabecular subtype of papillary carcinoma should be included as a separate entity in the WHO classification of thyroid tumours.

Papillary thyroid cancer and its surgical management

The surgical management in papillary thyroid cancer has been highly controversial. In the Department of Surgery (II), Kanazawa University Hospital, the surgical management especially for cervical lymph node metastases has changed since 1973 from a conservative approach to an aggressive one. In order to determine whether an aggressive approach is warranted, a retrospective multivariate analysis was carried out on 106 cases of papillary thyroid cancer. The patients have been followed for 10-28 years. Multivariate analysis was conducted following Cox's model. By this analysis, aggressive management appeared to have no impact on survival or relapse-free survival. However, age, sex, tumor size, and cervical lymphadenopathy were confirmed to be important prognostic factors in survival and/or relapse-free survival.

Carcinoma of the thyroid at a young age--a review of 23 patients

Twenty-three children and adolescents with thyroid carcinoma who were 20 years old or younger at the time of initial treatment were followed for a mean time of 9.5 years. Of the tumours, 21 were papillary and two follicular carcinomas. The majority (91%) of the 23 cases showed extra-thyroidal extension of the tumour. An association with chronic thyroiditis was observed in 30% of the cases. There was no history of irradiation of the head and neck in any patients. Relapse occurred in eight patients, lung metastases in two and local recurrences in six; one patient died from lung metastases 3 months after initial treatment. Male patients, advanced stage of tumour, less differentiated histological features and DNA aneuploidy were associated with a higher frequency of relapse. The prognosis of thyroid carcinomas in children and adolescents is not so good as is generally believed.