Early liver metastases in patients with medullary carcinoma of the thyroid gland

The Extent of Surgery for Thyroid Medullary Cancer

Aims

Evaluation of the impact of the extent of primary surgery and reintervention on the outcome of patients with medullary thyroid carcinoma.

Methods

Seventy-two patients with medullary thyroid carcinoma (MTC) were surgically treated between 1967 and 1992.

Results

Fifty-five cases were sporadic, 5 patients had MEN 2A, 4 MEN 2B syndrome and 8 familial non-MEN MTC; 1 patient had stage I disease, 30 patients stage II, 36 stage III and 5 stage IV. Sixty-four had their initial treatment at our center, and 8 came for subsequent treatment. At first treatment, 8 patients were subjected to partial thyroidectomy, 10 to total thyroidectomy, 53 to total thyroidectomy with neck dissection, and 1 to only radical neck dissection; postoperative serum calcitonin (Ct) levels returned to normal in 3, 6 and 27 patients, respectively. In the patient with only radical neck dissection, Ct levels remained elevated. No patient with Ct normalization after surgery became responsive to pentagastrin in the follow-up. Thirteen patients had a reoperation due to nodal relapse. At a mean follow-up of 5.7 years (6-252 months), the 10-year survival rate was 84.5% with a significant difference between patients under and over 40 years of age (96.4 vs 57%), between stage I-II (100%) and stage III, IV (83.8%, 0% respectively). At the last follow-up, 36 (50%) patients were alive and disease free and 26 were alive with disease (15 with distant metastases). Of the 10 deaths, 7 were due to tumor recurrence, 3 to 120 months after surgery.

Conclusions

Data suggest that an earlier diagnosis rather than more extensive surgery could improve survival and reduce recurrences. However, the least treatment required is total thyroidectomy plus central neck and upper mediastinum clearance and in addition, according to the extent of nodal involvement, mono- or bilateral neck dissection. To avoid ineffective reoperation due to distant (mainly liver) micro-metastases, persistent residual microscopic disease requires a more aggressive restaging.

Prognostic Value of Early Postoperative Calcitonin Level in Medullary Thyroid Carcinoma

Aims

Serum calcitonin (CT) assay is commonly used in the diagnosis and follow-up of medullary thyroid carcinoma (MTC). The aim of this study was to ascertain whether serum CT levels, measured in the first few days after surgery, could be used to evaluate the efficacy of treatment.

Methods

A group of 33 patients was studied. In all patients the follow-up was more than 20 months.

Results

Preoperatively basal CT serum levels were high in all patients. Twenty-four hours after surgery CT serum levels dropped to within the normal range in 8 patients and 72 hours after operation in 7 others. In this group 1 patient was at stage I, 11 at stage II and 3 at stage III. Basal and pentagastrin stimulated CT levels continued to be in the normal range in these 15 patients 6 and 12 months after surgery and at the subsequent year by follow-up visits. No clinical or radiological evidence of disease was found during the follow-up in this group. In the other 18 patients CT was reduced but still high 72 hours after surgery; 6 months later basal serum CT levels continued to be elevated or responsive to pentagastrin stimulation. In this group restaging showed tumor relapse in the thyroid bed in 2 patients, cervical lymphadenopathy in 11, and distant metastases (bone, liver) in 3.

Conclusions

Immediate postoperative CT serum levels seem to be the most useful index to evaluate the efficacy of surgical treatment and the presence of residual neoplastic tissue.

Medullary thyroid cancer: management guidelines of the American Thyroid Association

BACKGROUND

Inherited and sporadic medullary thyroid cancer (MTC) is an uncommon and challenging malignancy. The American Thyroid association (ATA) chose to create specific MTC Clinical Guidelines that would bring together and update the diverse MTC literature and combine it with evidence-based medicine and the knowledge and experience of a panel of expert clinicians.

METHODS

Relevant articles were identified using a systematic PubMed search and supplemented with additional published materials. Evidence-based recommendations were created and then categorized using criteria adapted from the United States Preventive Services Task Force, Agency for Healthcare Research and Quality.

RESULTS

Clinical topics addressed in this scholarly dialog included: initial diagnosis and therapy of preclinical disease (including RET oncogene testing and the timing of prophylactic thyroidectomy), initial diagnosis and therapy of clinically apparent disease (including preoperative testing and imaging, extent of surgery, and handling of devascularized parathyroid glands), initial evaluation and treatment of postoperative patients (including the role of completion thyroidectomy), management of persistent or recurrent MTC (including the role of tumor marker doubling times, and treatment of patients with distant metastases and hormonally active metastases), long-term follow-up and management (including the frequency of follow-up and imaging), and directions for future research.

CONCLUSIONS

One hundred twenty-two evidence-based recommendations were created to assist in the clinical care of MTC patients and to share what we believe is current, rational, and optimal medical practice.

Angiography-proven liver metastases explain low efficacy of lymph node dissections in medullary thyroid cancer patients

AIM

To report the role of liver angiography in the staging of medullary thyroid cancer (MTC) patients.

MATERIAL AND METHODS

Sixty MTC patients with persistent or recurrent hypercalcitonemia (n=49), a characteristic general symptom (diarrhea, n=4) or a normal basal calcitonin level without general symptoms (n=7) were investigated by dynamic liver CT, MRI and angiography between 06/1998 and 06/2002.

RESULTS

Dual-phase CT and MRI investigations identified hepatic metastases with relatively low frequency (8/58 on MRI, and 7/60 on CT). Angiography indicated liver involvement in 54/60 cases. The hepatic metastases were typically multiple, hypervascular, small foci (only 13 foci measured >/=10 mm). With one exception significant disease progression was not observed over 5 years of follow-up.

CONCLUSIONS

Liver angiography is a powerful tool to reveal hepatic metastases in MTC patients. Frequent, inoperable liver metastases in hypercalcitoninemic MTC patients demonstrate that secondary lymph node dissection is an inefficient technique for restoration of a normal calcitonin level.

Advances in the management of hereditary medullary thyroid cancer

This work draws on recent advances during the era of codon-oriented prophylactic surgery for hereditary medullary thyroid cancer (MTC). Milestones included identification of RET (REarranged during Transfection) as the susceptibility gene, introduction of prophylactic surgery on evidence of a RET germline mutation, revelation of genotype-phenotype correlations within the MEN 2 spectrum and demonstration of age-related progression of MTC. Novel surgical techniques, notably systemic microdissection and compartment-oriented surgery, have greatly enhanced surgical cure. Uncovering molecular pathways from RET genotype to MEN 2 phenotype should provide treatment options for RET mutation carriers whose MTC currently is too advanced for cure.

Surgical treatment of medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a malignancy of the parafollicular C cells of the thyroid gland. It occurs sporadically or as part of the multiple endocrine neoplasia type 2 (MEN 2) syndromes. Patients who have inherited a mutation in the RET proto-oncogene should have thyroidectomy early in life to prevent formation and spread of this cancer. Most patients with sporadic disease present with a palpable neck mass. The diagnosis is made by fine needle aspiration biopsy and by measuring calcitonin levels in the blood. Primary treatment consists of surgical resection including a total thyroidectomy, central neck nodal dissection and functional lateral neck nodal dissections. Most patients with a palpable primary tumour have nodal disease present at the time of operation, and nodal involvement is often bilateral. Adequate resection of the primary tumour and cervical lymph nodes is important to optimize outcome and minimize the risk of recurrent disease. Proper handling of the parathyroid glands prevents hypoparathyroidism. Following primary surgical resection, more than half of the patients will have recurrent disease with persistent elevation of calcitonin levels. Currently, there is no adequate systemic therapy for treating recurrent disease. Surgical reoperation or conservative observation are the best available options. Diagnostic laparoscopy for liver evaluation is the most sensitive diagnostic test to detect the presence of distant metastases.

Multiple endocrine neoplasias

Multiple endocrine neoplasia type 1 (MEN 1), and the multiple endocrine neoplasia type 2 syndromes (MEN 2A, MEN 2B, and familial non-MEN medullary thyroid carcinoma [FMTC]) encompass a wide range of endocrine problems, but arise from only two genes: the MEN 1 tumor suppressor gene and the RET proto-oncogene. MEN 1 is characterized by parathyroid hyperplasia, pancreaticoduodenal neuroendocrine tumors (PNTs), and pituitary adenomas. Surgery is the principal treatment modality for hyperparathyroidism and PNTs, but questions still remain concerning the timing and extent of surgery for PNTs. The MEN 2 syndromes are characterized by complete penetrance of medullary thyroid cancer. The MEN 2 syndromes differ in their variable expression of hyperparathyroidism, pheochromocytomas, and other clinical features. Genetic testing for mutations in the RET gene has revolutionized treatment by enabling thyroidectomies before significant disease occurs.

Medullary carcinoma of the thyroid

Medullary thyroid cancer (MTC) is a distinct C-cell tumor of the thyroid. We review the oncogenesis and management of both sporadic tumors and those tumors arising as part of specific inherited syndromes. The RET proto-oncogene plays a role in the development of inherited forms of MTC and has become important in the clinical management of patients and their families. The recognition of the high rate of regional nodal involvement has led to lymphadenectomy being strongly considered for patients undergoing thyroidectomy for MTC.

The surgical treatment of medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a unique disease in solid tumor oncology due to its ability to secrete calcitonin (iCT), a highly sensitive and specific serum marker of persistent or recurrent disease even at a microscopic level. The relatively long duration of survival experienced by most patients with MTC combined with the visible nature of surgical complications, when they occur, has caused most surgeons to take a conservative approach to the operative management and follow-up of patients with MTC. In contrast, the patient, family physician, and endocrinologist watch the iCT slowly rise, indicative of persistent and usually progressive invasive cancer. Amidst this clinical dilemma, we developed a standardized diagnostic and operative strategy to maximize local-regional tumor control and facilitate patient management.

Medullary carcinoma of the thyroid: prognostic factors and treatment recommendations

BACKGROUND

Because medullary thyroid carcinoma accounts for only 7% of all thyroid malignancies, data to support treatment strategies are scarce.

METHODS

We retrospectively reviewed treatment and outcome in 34 patients with MTC treated at Roswell Park between 1961 and 1995. Univariate analysis was performed using the variables age, sex, tumor size, N stage, and M stage.

RESULTS

Median survival was 4.7 years, with 51% and 32% of patients alive at 5 and 15 years, respectively. Nodal metastases were seen in 76% and distant metastases in 67% of all patients. More than 60% of the patients with nodal metastases survived longer than 10 years. Once diagnosed with distant metastases, 90% of the patients died within 5 years. Local failure rate with lobectomy was 44%, compared to 10% after total thyroidectomy (P < .02). Age, extrathyroid extension, and M stage portend a poor outcome. Nodal status had no statistically significant impact on survival.

CONCLUSION

Survival with tumors confined to the thyroid gland is independent of nodal status. Long-term survival in patients with distant metastases is rare. This study underscores the role of total thyroidectomy in the initial treatment and the need to develop effective adjuvant therapy for MTC.

Laparoscopic detection of hepatic metastases in patients with residual or recurrent medullary thyroid cancer

BACKGROUND

After initial operations for medullary thyroid cancer (MTC), reoperation with removal of metastatic disease confined to the neck may benefit some patients. The identification of distant metastases precludes the possibility of curative reoperation.

METHODS

Forty-one patients with hypercalcitoninemia after initial surgical treatment for MTC underwent laparoscopic (n = 36) or open (n = 5) examination and biopsy of the liver. Thirty-seven of these patients underwent imaging by computed tomography (CT), magnetic resonance imaging (MRI) of the liver, or both, and 17 underwent selective venous catheterization (SVC) with measurement of hepatic and peripheral vein stimulated calcitonin levels.

RESULTS

Liver metastases were found in eight patients, seven by laparoscopy and one by open examination. Seven of these patients had normal CT or MRI scans of the liver. Laparoscopy or open liver examination revealed metastases in 2 of 11 patients with elevated hepatic vein-peripheral vein stimulated calcitonin ratios (greater than 1.3). Metastases appeared as small (less than 5 mm), bright white nodules on the surface of the liver.

CONCLUSIONS

Direct examination and biopsy of the liver by laparoscopy may show small deposits of metastatic MTC in patients with normal CT and MRI scanning.

The value of lymph node dissection in hereditary medullary thyroid carcinoma: a retrospective, European, multicentre study

Clinical data of 139 patients with hereditary medullary thyroid carcinoma (HMTC) from nine european centres surgically treated from 1980 to 1991 were reviewed retrospectively to analyse the value of systematic versus selective lymphadenectomy (LA). Biochemical cure rate was significantly higher in patients who underwent LA compared to patients who did not. In nodal-positive HMTC, systematic LA compared to selective LA improved biochemical cure in small but not large tumours. In nodal-negative HMTC, systematic LA compared to selective LA could not improve biochemical cure in either small or large primary tumours. To prevent local recurrences with the risk of increased surgical and tumour-related morbidity, systematic LA should be performed in all HMTC patients regardless of the primary tumour stage. However, an improvement of biochemical cure by systematic LA seems to be possible only in nodal-positive small primary tumours without distant metastases.

Surgical management and follow-up of medullary thyroid carcinoma

Between 1977 and 1990 we operated on 33 patients with medullary thyroid carcinoma. We performed total thyroidectomy in 31 patients and central node dissection and/or lateral modified node dissection in 21 patients (63.3%). Two patients underwent radiotherapy after subtotal resection and tracheostomy. No perioperative death occurred. Twenty-five patients were followed (mean follow-up, 63.8 months) and 8 others were unavailable for follow-up. Three patients (1 with multiple endocrine neoplasia type IIB, 2 sporadic with distant metastases) died of their disease at 12, 18 and 36 months after initial operation. Of the remaining 22 patients, 4 with stage II disease were normocalcitoninemic even with pentagastrin stimulation, following total thyroidectomy and bilateral modified neck dissection and central node dissection. Eighteen other patients continued to have elevated calcitonin levels postoperatively. Only 10 patients with known cervical metastatic disease were reoperated upon. We performed extensive node dissection in all. In addition we resected recurrent tumor from the thyroid bed in 4 patients. Despite these extensive reoperations no patient became normocalcitoninemic. At the completion of the study (December 1991), 22 of the 25 patients followed were alive: 4 patients with normal calcitonin levels, baseline and after pentagastrin stimulation, and 18 with persistent mildly elevated calcitonin levels but no other evidence of disease. Our experience supports a very aggressive surgical approach at the time of the first operation for patients with medullary thyroid carcinoma. A lesser operation usually resulted in residual medullary thyroid carcinoma in the neck. We demonstrate the difficulty of achieving a cure by reoperation once the tumor becomes demonstrable by localization studies.

Selective venous sampling catheterisation for localisation of persisting medullary thyroid carcinoma

Selective venous sampling catheterisation was performed in 19 patients with medullary thyroid carcinoma without known distant metastases for persistent hypercalcitoninaemia after surgery. Calcitonin (CT) gradients were found in the neck and/or the mediastinum in 18 patients and in five patients at distant sites also. After venous catheterisation, 13 patients were subjected to repeat surgery. Neck and/or mediastinal tumour foci were found in 12 patients at the sites of the CT gradients. Of these, nine patients had only cervicomediastinal CT gradients: after reoperation, the serum CT level normalised in one, significantly decreased in five, and did not change in three, and no neck relapse occurred after a mean follow-up of 5.3 years. Distant metastases emerged clinically in all five patients with distant gradients and in only one of the 14 patients with no distant gradient. In conclusion, selective venous catheterisation is the most sensitive tool for the localisation of residual disease and for the early detection of distant metastases. However, in patients with only local disease, biochemical cure is rarely obtained after reoperation.

Microsurgical neck dissection for occultly metastasizing medullary thyroid carcinoma. Three-year results

BACKGROUND

Medullary thyroid carcinoma (MTC) metastasizes early into the regional lymph nodes, but distant metastases occur late. Modified radical neck dissection might improve the treatment results for occultly metastasizing MTC.

METHODS

The authors report 23 patients after a minimal follow-up of 2 years (median, 36 months). There were 11 female and 12 male patients. The mean age was 43 years (+/- 13 years). The surgical technique included the meticulous dissection of all compartments of the neck, resulting in a unilateral or bilateral modified radical neck dissection with the complete removal of the lymphatic and fatty tissue between important anatomical structures. The surgical boundaries extended cranially to the mastoid, caudally to the brachiocephalic vein involving a transcervical mediastinal dissection, and laterally to the edge of the trapezoid muscle. Ten patients were treated bilaterally and 13 patients unilaterally.

RESULTS

The basal calcitonin values of 18 of the 23 patients were postoperatively normalized with 4 patients having normal basal and pentagastrin-stimulated calcitonin levels. Five patients with persistently elevated basal serum calcitonin values had a marked reduction of the postoperative calcitonin levels compared with their preoperative concentrations. However, in these five patients histologic abnormalities precluded a surgical cure. The permanent complication rates were tolerable (4 of 33 neck dissections).

CONCLUSIONS

The microsurgically extended neck dissection can reduce basal and pentagastrin-stimulated serum calcitonin values to normal levels even after long intervals following primary thyroidectomy.

Localization of occult persisting medullary thyroid carcinoma before microsurgical reoperation: high sensitivity of selective venous catheterization

In 14 patients with occult persisting medullary thyroid carcinoma, tumor tissue was removed by microsurgical reoperation in 13 of 14 patients. This resulted in biochemical improvement in all but 1 patient and biochemical cure in 3 patients (21%). The lateral compartment of the neck or the upper mediastinum was involved in all but 1 patient. Before microsurgical reoperation, selective venous catheterization (SVC) for serum sampling along with serum calcitonin (CT) determination was done and compared to other localization methods. Tumor tissue could be localized correctly by SVC in 89% (CT gradient 1.21-2.02), computed tomography in 38%, and ultrasound in 28%. In patients with an elevated CT level after initial surgery and clinically occult disease, SVC is recommended for localization of tumor tissue. The affected side of the neck should be reoperated on with microdissection of the central and lateral compartment of the neck and the upper mediastinum. With this procedure, the cure rate of reoperation in patients with persistent occult MTC can be improved.

Nuclear DNA content of medullary thyroid carcinoma in a large family with the MEN-2A syndrome

Flow cytometry of medullary thyroid carcinoma (MCT) was performed in a large family with the MEN-2A syndrome. Of 15 family members with MCT five patients (10-27 yr) were without lymph node metastases. Six patients had a normal pentagastrin test after operation. All patients are alive and free of symptoms of MCT 6-9 yr after total thyroidectomy and an ablative dose of 131-I. In 12 of the 15 patients with MCT flowcytometry of paraffin-embedded tissue could be performed. The majority of all tumors (n = 9) were classified as peridiploid. Metastatic tumor, 6 years after thyroidectomy, in one of the patients was diploid. Only two MCT were clearly aneuploid. In one patient the tumor was tetraploid. We conclude that the majority of the MCT patients in this family with the MEN-2A syndrome have no or limited ploidy aberrations in their tumors, which correlates well with the favourable prognosis of familial MCT.

Thyroid cancer

There have been important recent advances in our understanding of the biologic nature of thyroid cancer and in the early diagnosis of the disease. Despite these advances, there is still considerable controversy over the management of thyroid cancer, including the extent of surgery, the indications for the use of iodine-131, the effectiveness of thyroid-stimulating hormone suppression, and the prediction of outcome. In this review, the current status of the diagnosis and management of the various types of thyroid cancer are carefully reviewed and extensively documented.