The Extent of Surgery for Thyroid Medullary Cancer

Medullary thyroid carcinoma

INTRODUCTION

Medullary thyroid carcinoma (MTC) constitutes approximately 5-10% of all thyroid cancers. Although the tumor forms in the thyroid, it doesn't originate from thyroid cells, but from the C cells or parafollicular cells which produce and release a hormone called calcitonin (CT). Starting from the second half of the 1900s, MTC was progressively studied and defined.

AREAS COVERED

This study aims to analyze the history, clinical presentation and biological behavior of MTC, bio-humoral and instrumental diagnosis, molecular profiling, genetic screening, preoperative staging and instrumental procedures, indispensable in expert and dedicated hands, such as high-resolution ultrasonography, CT-scan, MRI and PET/TC. We examine recommended and controversial surgical indications and procedures, prophylactic early surgery and multiple endocrine neoplasia surgery. Also, we discuss pathological anatomy classification and targeted therapies. The role of serum CT is valued both as undisputed and constant preoperative diagnostic marker, obscuring cytology and as early postoperative marker that predicts disease persistence.

EXPERT OPINION

With a complete preoperative study, unnecessary or useless, late and extended interventions can be reduced in favor of tailored surgery that also considers quality of life. Finally, great progress has been made in targeted therapy, with favorable impact on survival.

Medullary thyroid cancer outcomes in patients with undetectable versus normalized postoperative calcitonin levels

BACKGROUND

Calcitonin (Ct) is a sensitive diagnostic biomarker and one of the most important prognostic factors in medullary thyroid cancer (MTC). This study aimed to evaluate progression-free survival and recurrence rates of MTC associated with undetectable compared with normalized serum Ct levels after surgery.

METHODS

This retrospective observational study included patients operated for MTC at the Digestive and Endocrine Surgery Department of Lyon Sud Hospital Centre between 2000 and 2019. Clinical and pathological factors were correlated with postoperative Ct concentrations. Undetectable and normalized Ct concentrations were defined as below 2 pg/ml and 2-10 pg/ml respectively.

RESULTS

Overall, 176 patients were treated for MTC, and 127 were considered biochemically cured after surgery. Of these, 24 and 103 had normalized and undetectable Ct concentrations respectively. Patients with Ct level normalization had a 25 per cent risk of disease recurrence, compared with 3 per cent in patients with undetectable Ct levels after surgery. The presence of metastasis in two or more compartments was predictive of failure to achieve undetectable Ct concentrations after surgery and an increased risk of recurrence.

CONCLUSION

Among patients with biochemically cured MTC, those with undetectable or normalized Ct concentrations after surgery had different risks of recurrence. Simply assessing postoperative Ct normalization can be falsely reassuring, and long-term follow-up is needed.

Persistent Hypercalcitoninemia in Patients with Medullary Thyroid Cancer

Medullary thyroid carcinoma is a highly malignant and progressive disease. Surgery is the only effective treatment. Calcitonin is a significant marker for medullary thyroid carcinoma, and due to its sensitivity it represents a useful tool for the follow-up. The outcome of patients affected by medullary thyroid carcinoma depends on tumor size, lymph node involvement, and adequacy of primary surgical management. In the present study, the authors reviewed their own experience in the cure of medullary thyroid carcinoma. Forty-one patients operated for sporadic medullary thyroid carcinoma were included. Indications for surgery, inclusive of lymphectomy techniques, timing of redo surgery, and the meaning of calcitonin levels in highlighting disease are extensively discussed. Patients with elevated calcitonin levels and favorable outcome are considered, together with the various diagnostic tools to be employed during patient workup.

Biochemical cure after reoperations for medullary thyroid carcinoma: a meta-analysis

BACKGROUND

Despite meticulous surgical techniques, calcitonin levels remain detectable in 40 % to 66 % of patients after initial surgery for medullary thyroid carcinoma (MTC), and the optimal surgical management for persistent or recurrent disease remains controversial. Previous studies suggest that biochemical cure, defined by normalization of postoperative calcitonin measurements, predicts disease-free survival. Reoperative approaches range from targeted removal of detectable disease to comprehensive compartment-oriented lymph node clearance.

METHODS

A proportional meta-analysis of clinical case series of postoperative calcitonin clearance after reoperation for MTC was performed. Studies were obtained from PubMed, Embase, Scopus, and the Cochrane Library.

RESULTS

Twenty-seven articles capturing data of 984 patients met the inclusion criteria for the meta-analysis. Overall, normalization of calcitonin after reoperation for MTC occurred in 16.2 % of patients [95 % confidence interval (CI) 14.0-18.5]. Stratified by operative procedure, targeted selective lymph node removal procedures had a normalization of calcitonin in 10.5 % of patients (95 % CI 6.4-14.7), while compartment-oriented procedures had a higher rate of normalization at 18.6 % (95 % CI 15.9-21.3).

CONCLUSIONS

The rate of calcitonin normalization after reoperation for MTC is enhanced through use of a meticulous compartment-oriented lymph node dissection. Compartment-oriented lymph node dissection results in calcitonin normalization in 18.6 % of reoperative MTC patients and is the procedure of choice in patients in whom the goal is biochemical cure.

Evidence-based approach to the management of sporadic medullary thyroid carcinoma

Medullary thyroid carcinoma (MTC) is a rare malignancy of the thyroid C cells. It occurs in hereditary (25% of cases) and sporadic (75%) forms. Sporadic MTCs frequently metastasize to cervical lymph nodes. Thorough surgical extirpation of the primary tumor and nodal metastases by compartment-oriented resection has been the mainstay of treatment (level IV evidence). Surgical resection of residual and recurrent disease is effective in reducing calcitonin levels and controlling complications of central neck disease (level IV evidence). Radioactive iodine, external beam radiation therapy, and conventional chemotherapy have not been effective. Newer systemic treatments, with agents that target abnormal RET proteins hold promise and are being tested in clinical trials for patients with metastatic disease.

Natural history, diagnosis, treatment and outcome of medullary thyroid cancer: 37 years experience on 157 patients

AIM

The analysis of a 37-year retrospective study on diagnosis, prognostic variables, treatment and outcome of a large group of medullary thyroid cancer (MTC) patients was conducted, in order to plan a possible evidence-based management process.

METHODS

Between Jan 1967 to Dec 2004, 157 consecutive MTC patients underwent surgery in our centre: 60 males and 97 females, mean age 47.3 years (range 6-79). Total thyroidectomy was performed in 143 patients (91.1%); central compartment (CC) node dissection (level VI) in 41 patients; central plus lateral compartment (LC) node dissection (levels II, III, and IV) in 82 patients. Subtotal thyroidectomy was initially performed in 14 cases: 10 of them were re-operated because of persistence of elevated serum calcitonin levels.

RESULTS

After a median post-surgical follow-up of 68 months (range 2-440 months), 42.9% of patients were living disease-free, 39.8% were living with disease, 3.1% were deceased due to causes different from MTC, and 3.2% were deceased due to MTC. The overall 10-year survival rate was 72%. At uni-variate statistical analysis (a) patient's age at initial treatment (>45 years; >/=45 years), (b) sporadic vs. hereditary MTC, (c) disease stage, and (d) the extent of surgical approach resulted as significant variables. Instead, at multivariate statistical analysis, only (a) patient's age at initial diagnosis, (b) disease stage, and (c) the extent of surgery resulted as significant and independent prognostic variables influencing survival.

CONCLUSION

The presence of lymph node and distant metastases at first diagnosis significantly worsened prognosis and survival rate in our series. Early diagnosis of MTC is very important, allowing complete surgical cure in Stages I and II patients. Due to the relatively bad prognosis of MTC, especially for disease Stages III and IV, it appears reasonable to recommend radical surgery including total thyroidectomy plus CC lymphoadenectomy as the treatment of choice, plus LC lymphoadenectomy in patients with palpable and/or ultrasound enlarged neck lymph nodes.

Medullary thyroid carcinoma: multivariate analysis of prognostic factors influencing survival

BACKGROUND

Medullary thyroid carcinoma (MTC) is a rare development of thyroid cancer with a no negligible mortality rate. Our aim was to determine factors that predict outcome in patients with MTC.

METHODS

We reviewed the records of all patients with MTC (n=56) who underwent treatment at our institution between January 1990 and December 2000. Univariate and multivariate analysis of clinicopathologic predictors of MTC outcome were performed to identify subsets of patients with different probabilities in terms of overall survival, local recurrence, and distant metastases.

RESULTS

Multivariate analysis demonstrated that a statistically significant decrease in overall survival is associated with T4b tumours (p=0.06), the presence of distant metastases at the time of presentation (p=0.033), lymphatic invasion (p=0.099), and postoperative treatment (p=0.045).

CONCLUSIONS

The analysis of survival curves of patients with MTC shows that the occurrence of locoregional and distant metastases occurs preferentially within the first 5 years, which identifies this as a crucial period for follow-up. In this series of patients with MTC, the tumours classified as T4b, metastases at presentation, the presence of lymphovascular invasion, and postoperative treatment were the most important prognostic features. At present, there is no available beneficial adjuvant therapy. However, as the development of molecular therapy progresses, it should be tested in clinical trials with the purpose of achievement of novel targeted therapies for selected MTC patients with risk factors.

Current approaches and perspectives in the therapy of medullary thyroid carcinoma

BACKGROUND

Medullary thyroid carcinoma (MTC) is a neuroendocrine tumor derived from parafollicular cells. At present, surgery is the most important treatment for MTC.

METHODS

We describe the current approaches of MTC treatment (surgery, chemotherapy, radiation therapy, and biologic therapy).

RESULTS

MTC is currently approached surgically in the main part through total thyroidectomy and compartment-oriented microdissection of cervicomediastinal lymph nodes. Substitutive l-thyroxine administration together with close clinical monitoring and the measurement of basal and stimulated serum calcitonin are subsequently performed. Radiotherapy and chemotherapy play a marginal role in advanced MTC. Recently, it has been found that somatostatin analogs and type I interferon are able to control the neuroendocrine symptoms induced by advanced MTC and that they provide clinical benefit by improving the lifestyle of these patients.

CONCLUSION

Although these agents are poorly active in inducing a shrinkage in tumor mass, the combined use of different biologic agents and cytotoxic drugs needs to be explored in advanced MTC. However, at present, surgery is the only curative treatment for MTC.

Familial medullary thyroid carcinoma (FMTC). Study of one family (treatment criteria)

AIM

The nosology of familial medullary thyroid carcinoma (FMTC) has been described as a distinct pathology, genetically determined and with autosomal dominant transmission with a gene penetrance of almost 100%. The diagnosis of this morbid condition can be made if at least four members of the same family are affected by calcitonin-secreting C-cell carcinoma.

METHODS AND RESULTS

We report the analysis of a family in which FMTC was diagnosed between 1993 and 1998. Of the five patients we confirmed as being affected by FMTC, we were able to perform a prophylactic thyroidectomy in only one case. The high possibility of lymph-node metastasis at the time of clinical diagnosis (52-75%), and the high morbidity and radio-chemo-resistance to adjuvant therapies, indicate total thyroidectomy with central lymph-node dissection.

CONCLUSION

It appears that preventive lymphadenectomy does not substantially improve survival, while pre-clinical diagnosis is of greater importance than surgery in improving survival and preventing recurrence. Total preventive thyroidectomy has been recommended in all carriers of ret genetic defects, even in families at risk with mutations of the 618 or 620 codon, because the penetrance of FMTC approaches 100%, and a 100% accordance between presence of the disease and gene carrier status is reported. This procedure would therefore represent the only possibility of achieving a 100% cure in subjects affected by familial medullary thyroid carcinoma.

Long-term follow-up of patients with medullary carcinoma of the thyroid

BACKGROUND

All patients with medullary carcinoma of the thyroid (MCT) diagnosed in Sweden during 1959 through 1981 were identified. There were 113 males and 134 females with a mean age of 51.6 years (range, 11-85 years). The cohort was followed with regard to survival to identify prognostic factors. The results 5 and 10 years after diagnosis have been presented previously.

METHODS

The purpose of this study was to examine to what extent those prognostic factors found in the authors' previous analyses remained independent prognostic factors for survival 10 years or longer after diagnosis. The follow-up period was extended an additional 5 years and ranged between 11 and 32 years.

RESULTS

The relative survival rate was 69.2% and 64.7%, respectively, 10 and 15 years after diagnosis. The survival rate was worse after excluding those patients with a family history of MCT (60.8% and 53.7%, respectively, 10 and 15 years after diagnosis). In multivariate analyses, age, tumor size, stage of the disease at diagnosis, tumor amyloid content and an euploid DNA pattern were found to be independent prognostic factors. However, in analyses of survival 10 years or longer after diagnosis only stage, tumor size, and age remained independent prognostic factors.

CONCLUSIONS

There is still an excess mortality 10 years or longer after a diagnosis of MCT. However, the authors identified 3 groups of patients in whom the survival 10 years or longer after diagnosis did not differ from that of the general population: patients with a family history of MCT detected by screening, those with tumor size < 1 cm, or those with early stage disease at diagnosis.

Multivariate analysis of patients with medullary thyroid carcinoma. Prognostic significance and impact on treatment of clinical and pathologic variables

BACKGROUND

The prognostic significance of the histologic and clinical features of medullary thyroid cancer (MTC) and their impact on therapy and outcome have been evaluated infrequently in the same series.

METHODS

Fifty-tree patients with MTC (32 females, 21 males; 44 sporadic, 9 familial MTC [4 families]; mean age: 46.11 +/- 14.04 years) who were operated on consecutively between 1970 and 1992 were studied. All pathology slides were reviewed. Patients were followed with clinical examination, serum calcitonin (CT), and carcinoembryonic antigen (CEA) assay, and imaging procedures (median follow-up: 4 years; mean: 5.66 +/- 4.85 years; range: 0-19 years). Impact on survival was evaluated with Kaplan-Meier survival curves compared with the log rank test for these variables: familiarity, sex, age, pT, N, M, stage, histotype, necrosis, calcitonin, gene-related peptide (CGRP), CT, CEA, thyroglobulin, chromogranin A, chromogranin A PHE5, neuron-specific enolase, amyloid, argyrophilia, synaptophysin Y38, external radiotherapy, chemotherapy, 131I therapy, postsurgical serum CT, and postsurgical serum CEA, Multivariate analysis was performed using Cox's proportional hazards model for statistically significant factors (P < 0.05).

RESULTS

Ten- and 15-year cause-specific survival were 71% and 54%. Nineteen patients (35.8%) appeared to be cured and 8 (15.1%) were alive with high serum CT levels but no proven metastases. Eight recurrences as distant sites and four at the cervical region were diagnosed. Stage M, N, necrosis, and postsurgical CT and CGRP were significant prognostic factors for survival by univariate analysis, but only the stage was significant by multivariate analysis.

CONCLUSIONS

Stage and postsurgical serum CT level are the most powerful and the most useful prognostic factors for MTC, while survival did not correlated significantly with the majority of available immunohistochemical markers.