Prognostic factors in patients dying of well-differentiated thyroid cancer

Prognostic factors in patients with multiple recurrences of well-differentiated thyroid carcinoma

Introduction. Patients with multiple recurrences of well-differentiated thyroid carcinoma (WDTC) have markedly reduced overall survival when compared with those who have ≤1 recurrence of their disease. The purpose of this investigation is to identify prognostic factors for mortality in this subgroup. Methods. Patients with multiple recurrences of WDTC were retrospectively identified from the thyroid cancer database at Mount Sinai Hospital, Toronto (1963–2000). Data on patient, tumor, and recurrence characteristics were collected, and each patient was given a MACIS score. Results. A total of 31 patients were identified (11 male, 20 female; 16–83 years). Using univariate analysis, age >45, stage III/IV disease, distant metastasis, vascular invasion, MACIS score >6, and time to recurrence of <12 months were found to be significant predictors for mortality in this subgroup. Conclusions. Patients with multiple recurrences of WDTC follow a distinct clinical course, marked with multiple treatment failures and a substantial risk of mortality.

High-dose radioiodine treatment for differentiated thyroid carcinoma is not associated with change in female fertility or any genetic risk to the offspring

BACKGROUND

We tried to evaluate the female fertility and genetic risk to the offspring from the exposure to high-dose (131)I by assessing the pregnancy outcomes and health status of the children of female patients with differentiated thyroid cancer who had received therapeutic doses of (131)I.

MATERIALS AND METHODS

From 1967 to 2002, a total of 1,282 women had been treated with (131)I. Of these patients, 692 (54%) were in the reproductive age group (18-45 years). Forty women had a total of 50 pregnancies after high-dose (131)I. Age at presentation ranged from 16 to 36 years (mean, 23 +/- 4 years). Histopathology was papillary thyroid cancer in 32 cases and follicular thyroid cancer in 8 cases.

RESULTS

Single high-dose therapy was given in 30 cases, 2 doses were given in 7 cases, 3 doses were given in 2 cases, and four doses were given in 1 case in which lung metastases had occurred. In 37 patients (92%), disease was successfully ablated before pregnancy. Ovarian absorbed-radiation dose calculated by the MIRD method ranged from 3.5 to 60 cGy (mean, 12 +/- 11 cGy). The interval between (131)I therapy and pregnancy varied from 7 to 120 months (37.4 +/- 28.2 months). Three spontaneous abortions occurred in 2 women. Forty-seven babies (20 females and 27 males) were born. Forty-four babies were healthy with normal birth weight and normal developmental milestones. Twenty women delivered their first baby after (131)I therapy. The youngest child in our series is 11 months of age, and the oldest is 8.5 years of age.

CONCLUSIONS

Female fertility is not affected by high-dose radioiodine treatment, and the therapy does not appear to be associated with any genetic risks to the offspring.

Distribution of lymph node micrometastasis in pN0 well-differentiated thyroid carcinoma

BACKGROUND

The role of lymph node dissection in the treatment of differentiated thyroid carcinoma remains controversial, and the benefit of therapy is debatable. This study was designed to identify the precise localization of lymph node micrometastases (LNMM) and map their cervical involvement in relation with the tumor location within the thyroid gland.

METHODS

A total of 2551 cervical lymph nodes were obtained from 80 patients with well-differentiated thyroid cancer. They were diagnosed as clear lymph nodes by hematoxylin and eosin stain and then examined immunohistochemically with cytokeratins (AE1/AE3) for evidence of micrometastases.

RESULTS

Forty-two patients out of 80 (53%) had LNMM. Forty-eight patients (60%) had the tumor confined to only one third of 1 of the 2 lobes of the thyroid gland or isthmus. The frequencies and locations of LNMM in patients were 50% (3/6) in the deep upper cervical nodes, with tumors localized in the upper third; 31% (5/16) in the paraglandular nodes, with tumors affecting the middle third; 63% (12/19) in the paratracheal nodes, with tumors affecting the lower third of the thyroid lobe; and 71% (5/7) in the pretracheal nodes in the isthmus-located tumor. All the LNMM occurred on the ipsilateral side of the tumor.

CONCLUSIONS

When thyroid carcinoma is located in the upper third of the thyroid lobe, the LNMM are found in the direction of upward lymphatic flow. When the tumor is located in the lower third or isthmus, LNMM are directed downward. In addition, early thyroid carcinoma micrometastases do not cross the midline but remain on the ipsilateral side of the tumor.

Extent of surgery for intermediate-risk well-differentiated thyroid cancer

BACKGROUND

Methods of assigning patients with papillary or follicular thyroid cancer (well-differentiated thyroid cancer) to risk groups for the purpose of determining appropriate therapy have been developed. Despite these efforts, the optimal extent of surgery for intermediate-risk patients remains controversial.

METHODS

A retrospective study was conducted of 208 patients with well-differentiated thyroid cancer (DTC) from two institutions. Univariate and multivariate analysis of patient- and tumor-related variables was performed. A regression model was obtained, three risk groups (low, intermediate, and high) were defined, and survival curves were generated.

RESULTS

Prognostic variables were age (P <0.001), distant metastases (P <0.001), tumor size (P <0.001) and an aggressive growth pattern (P = 0.03) by univariate analysis and age (P <0.001) and distant metastases (P <0.001) by multivariate analysis. Tumor size (P = 0.07) was included in the regression model. Total thyroidectomy appeared to provide a survival advantage for intermediate risk patients. High-risk patients treated by lobectomy had a poorer prognosis.

CONCLUSIONS

Total thyroidectomy may provide a survival advantage for intermediate-risk patients with DTC. A prospective randomized trial with 200 such patients is required to confirm this finding.

Characteristics and prognostic factors in patients with differentiated thyroid cancer who underwent a total or subtotal thyroidectomy: surgical approach for high-risk patients

Differentiated thyroid cancer grows slowly in general. But some patients repeat recurrence and progress finally to death. To clarify the difference of their prognosis and establish the appropriate thyroid surgery, we studied 105 patients with differentiated thyroid cancer who were treated with total or subtotal thyroidectomy, excluding those with small tumors, under uniform conditions regarding thyroidectomy. There were 77 women and 28 men aged 19 to 76 years (mean 54.7 years). More than 60% (alive) were followed up for longer than 10 years. Thirty-eight (36%) patients had recurrences. There were 19 deaths. Twelve of 31 patients with locoregional recurrence died and 7 of these 12 died of locoregional control failure (neck and mediastinum). Age at first operation, tumor size, and local tumor extension increased the rate of recurrence significantly. Multivariate analysis confirmed that age, locoregional recurrence, and distant metastasis significantly affected survival. Although lymph node metastases were not a prognostic factor, for patients at high risk for recurrence who are older, and have large tumors with invasion, complete resection of cervical lymph nodes is advised to prevent local recurrence and prolong the disease-free interval. Prolongation of the disease-free interval may lead to prolonged survival time.

Comparison of Nuclear DNA Content in Locally Invasive and Noninvasive Papillary Carcinoma of the Thyroid Gland

Extrathyroidal invasion of papillary carcinoma of the thyroid gland has a very bad prognosis. A retrospective study was performed on 40 specimens from patients with papillary carcinoma of the thyroid gland to find out whether DNA ploidy correlated with aggressive tumor behavior. The nuclear DNA content of 20 locally aggressive papillary thyroid carcinomas was studied by flow cytometry. The results were compared with those of a matched control group of 20 patients with noninvasive papillary tumors. Forty percent of the tumors with spread to extrathyroid tissue were aneuploid, whereas all the tumors without such extension were diploid. This difference was statistically significant ( p < 0.003). The data suggest that the differentiation of locally noninvasive and invasive papillary thyroid carcinomas may be potentially possible by nuclear DNA determination.

Prognostic factors in patients with recurrent differentiated thyroid carcinoma

BACKGROUND

Approximately 20% of patients with thyroid carcinoma have relapse. To evaluate the factors affecting their disease-free survival and prognosis, we studied 68 patients with recurrent differentiated thyroid carcinoma, ranging in age from 5 to 73 years (mean: 47.6 years). Three-fourths of patients were followed for >10 years. Thirty-nine patients were treated with total or subtotal thyroidectomy at first operation; the remainder underwent lesser operations. Fifty-six patients had local recurrence, mostly lymph node infiltration. Twenty-six patients died.

METHODS

Survival curves were constructed using the Kaplan-Meier method. Factors affecting relapse and survival were tested by univariate or multivariate analysis.

RESULTS

Univariate analysis identified age at diagnosis, local tumor extension, and surgical method as significant factors for disease-free survival. These three factors and histology were significant prognostic factors. Multivariate analysis showed age, histology, and disease-free interval as significant and independent variables.

CONCLUSIONS

In high-risk patients, complete resection of thyroid tissue and cervical lymph nodes is critical.

Well-differentiated thyroid carcinoma

PURPOSE

This study presents our experience with 728 patients treated in our department for well-differentiated thyroid carcinoma between 1954-1994.

MATERIALS AND METHODS

The retrospective evaluation of the prognostic implications of the clinical and pathological findings was performed. Age, sex, histological variants, tumor size, and locoregional and distant spread were evaluated as risk factors in relation to the prognosis.

RESULTS

During follow-up, which ranged from 1 to 31 years, 125 locoregional and/or distant metastases developed (17.2% of the patients), 87 of which occurred in the first 10 years after initial therapy. Thirty-two patients with papillary cancer and 20 with follicular cancer died of causes related to malignancy of the thyroid.

CONCLUSION

The experience gained in our department has led us to adopt an aggressive approach in the treatment of patients with well-differentiated carcinoma of the thyroid gland.

Papillary and follicular thyroid carcinoma: the treatment results of 357 patients at the National Kyushu Cancer Centre of Japan

During the period from April 1974 to March 1993, 357 patients received surgical treatment for papillary and follicular carcinoma of the thyroid gland at the Department of Head and Neck Surgery of National Kyushu Cancer Centre, Japan. In this paper, we review the various clinico-pathological features of these patients and analyse their influence on patient survival. While the majority of the patients' ages ranged from the third through seventh decade, only the patients older than 40 years old died. In papillary carcinomas, there was a statistically significant difference in the survival rate between younger (less than 45 years old) and older (45 years of age or older) patients. The rate of patients who died of thyroid cancer also increased in the cases with extra-thyroidal tumour invasion, and metastasis to distant organs. A multivariate analysis also showed that the age, extrathyroidal invasion and distant metastasis are significant prognostic factors. However, sex, histology and lymph node metastasis were not prognostic factors for survival.

Fatal differentiated thyroid cancer

Thirty-five patients who died of differentiated thyroid cancer were analyzed for factors affecting survival. The neck was the most common initial site of recurrence (62.0%). The lung was the most common metastatic site (56.7%). Major sites associated with death were locoregional recurrence (neck and mediastinum: 48.6%) and bone metastases (22.9%). By univariate analysis, local tumor extension, type of initial surgery, and residual tumor and/or existence of distant metastases at the initial operation were significant factors affecting survival. Stepwise multivariate analysis revealed that invasion of the esophagus and/or carotid artery shortened survival and that multiple surgeries extended survival. Our results suggest that to improve survival in patients with differentiated thyroid cancer, better locoregional control, including multiple surgical resection, is necessary.

Impact of lymph node metastasis in differentiated carcinoma of the thyroid: a matched-pair analysis

BACKGROUND

Cervical lymph node metastasis in differentiated thyroid carcinoma has mostly been found to have little relationship to prognosis. However, some studies report nodal involvement to be an adverse factor, while others have found it to be favorable. We have undertaken a matched-pair analysis of previously untreated patients, with and without ipsilateral neck metastasis, to examine the significance of nodal spread in patients with otherwise equivalent prognostic factors for differentiated thyroid cancer.

METHOD

From a database of 931 patients, treated from 1930 to 1980, we used a computer to match patients with confirmed lateral neck metastasis (N1) to those who were stage NO, and had the following identical prognostic factors: no distant metastasis, age (within 4 years), and tumor size, histology, and intrathyroidal extent. When possible, matches were also made for gender, multifocality, and extent of thyroid surgery. Survival and treatment failures were analyzed, with and without stratification for age.

RESULTS

We were able to select 100 N1 patients with corresponding NO patients, sharing the major prognostic risk factors as listed. Overall, there was no difference in survival, although N1 patients more often had recurrence. Mortality increased with age. Analysis at high-risk age (45 years and older) showed significantly more recurrences in N1 patients (p = .008). Twenty-year survival in N1 patients over the age of 45 was lower than that of NO patients. On the other hand, under the age of 45, N1 patients had better survival. These differences, however, did not reach statistical significance.

CONCLUSION

Nodal involvement in older patients with thyroid cancer increases the risk of recurrence, although no significant difference in survival is observed in relation to age.

Follicular carcinoma of the thyroid

BACKGROUND

Follicular carcinomas of the thyroid are less common than papillary carcinomas of the thyroid, and the available data on prognostic factors are relatively scant. A retrospective study covering four decades was undertaken to evaluate clinical and pathologic findings with regard to their effect on prognosis.

METHODS

In 195 cases of follicular carcinoma treated from 1954 to 1991 age, sex, histologic type (minimally invasive vs. widely invasive), tumor size, and local, regional, and distant spread as well as the contribution of treatment to survival were evaluated in relation to prognosis.

RESULTS

Age was a significant prognostic factor: there was 100% survival of patients younger than 20 years of age at diagnosis and only one death in the 20-39 year age group. Sex was not a significant prognostic factor, although there was a tendency to a better prognosis in females. Tumor size was significant, more than 6 cm having a poor prognosis. Blood vessel invasion influenced prognosis for the first 10 years. The presence of distant metastases was significant regarding survival. Lymph node involvement had a negative effect on the outcome.

CONCLUSIONS

The factors of age, tumor size, invasion of blood vessels, and distant metastases are significant predictors of survival for patients with follicular carcinoma, whereas sex is not; regional spread needs to be evaluated further.

Outcome of 249 patients attending a nuclear medicine department with well differentiated thyroid cancer; a 23 year review

249 patients with well differentiated thyroid cancer attended the Nuclear Medicine Department of the Royal Liverpool Hospital (formerly housed at the Liverpool Clinic) from 1967 to 1990. Papillary carcinoma was histologically evident in 68% of patients and follicular carcinoma in 32%. Fifteen percent of all patients died of their cancer. The extent of initial surgery did not appear to influence the recurrence of disease, nor the patient survival. Univariate analysis showed that males had a worse survival rate than females during the 5 years after diagnosis but thereafter survival rates were similar. Multivariate analysis indicated that unfavourable survival factors were "age over 45 years at diagnosis" and "presence of distal metastases". Survival was not significantly different with or without 131I ablation where there were no distal metastases. Outcome of pregnancy after 131I ablation gave no cause for concern. No serious complications were observed following 131I therapy. Serum thyroglobulin tests were introduced only half way through the review period and were helpful in predicting the presence of tumour recurrence but these data are to be discussed in another communication.

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.

Prognostic significance of cervical lymph node metastases in differentiated thyroid cancer

During the last decade, several analyses of prognostic factors for differentiated thyroid cancer (DTC) have been reported. Although these studies have established a framework for rational treatment planning, they have not fully answered questions regarding the prognostic significance of cervical lymph node metastases. An analysis of patients treated for DTC at our institution over a 34-year period has shown several factors to be significant by log-rank analysis, including the presence of cervical lymph node metastases, age greater than or equal to 50 years, a primary cancer size of greater than 3.0 cm, and distant metastases. Further analysis has shown the node-negative and node-positive patient groups to be similar in regard to age, size of primary cancer, and the presence of distant metastases. This report compares our data with those of other studies that have investigated the association of cervical lymph node metastases and a poorer prognosis in patients with DTC. When considered as a group, these studies support the finding of the prognostic significance of cervical lymph node metastases, particularly that of palpable lymphadenopathy in older patients.

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.

Frequency and experience with carcinoma of the thyroid at a private, a Veterans Administration, and a university hospital

We evaluated the treatment experiences with thyroid carcinoma at a private, a Veterans Administration, and a University hospital to determine the frequency, treatment, and outcome of patients with this uncommon malignant tumor. All 120 patients with thyroid carcinoma were identified through hospital tumor registries between 1953 and 1988, representing 0.3% of the total cancer registry cases during this period. Well-differentiated carcinoma of the thyroid represented 73%, medullary carcinoma 7%, poorly differentiated carcinoma 18%, and Hürthle cell carcinoma 2% of histologic varieties. Seventy-eight percent of patients were treated initially by surgery or by surgery plus postoperative irradiation. The remaining patients received other treatment. At 10 years after treatment, 90% of patients with well-differentiated carcinoma survived, while only 20% of patients with medullary and poorly differentiated carcinoma survived. Sixty percent of recurrences for all histologic types appeared within the first 12 months after treatment. Patients with well-differentiated carcinoma had sporadic recurrences over a 21-year-period. Recognition of these time intervals allows for better follow-up management.