Survival in patients with medullary thyroid cancer after less than the recommended initial operation

Changes of biochemical factors and the effect on recurrence of medullary thyroid carcinoma after surgery

Objective

Medullary thyroid carcinoma (MTC) is a rare malignancy secreting calcitonin (Ctn). We aimed to analyze the relationship between Ctn levels at different time points in patients with MTC, and evaluate its predictive effect on recurrence.

Methods

A retrospective study of patients diagnosed with MTC in a large medical center were conducted in northern China. The interrelationships between preoperative Ctn, normalization of postoperative serum Ctn at the first month (NPS), and long-term biochemical cure as well as their predicting roles on structural recurrence were assessed.

Results

A total of 212 patients were included in this study. The median follow-up time was 59.5 months. The 5- and 10-year cumulative disease-free survival rates were 81.5 % and 66.8 %, respectively. NPS (OR: 216.33, 95 % CI: 28.69-1631.09, P < 0.001) and absence of structural recurrence (OR: 61.71, 95 % CI: 3.90-975.31; P = 0.003) were associated with biochemical cure. Non-biochemical cure (OR: 28.76; 95 % CI: 2.84-290.86; P = 0.004, HR: 14.63, 95 % CI: 2.27-94.07, P = 0.005), larger tumor size (OR: 8.79, 95 % CI: 2.12-36.40, P = 0.003, HR: 5.41, 95 % CI: 2.04-14.37, P = 0.001), and multifocality (OR: 4.02, 95 % CI: 1.06-15.17, P = 0.040, HR: 3.00, 95 % CI: 1.18-7.60, P = 0.021) were unfavorable independent predictors of structural recurrence and disease-free survival. For sporadic MTC confined to the thyroid lobe, there was no difference in biochemical or structural prognosis between the different surgeries in the subgroup analysis.

Conclusions

NPS, rather than preoperative Ctn, predicted long-term biochemical cure for MTC. Non-biochemical cure, larger tumor burden including larger tumor size and multifocality at initial surgery, served as worse prognostic predictors.

Extent of Surgery for Medullary Thyroid Cancer and Prevalence of Occult Contralateral Foci

Importance

Standard treatment for patients with medullary thyroid cancer (MTC) consists of total thyroidectomy with central neck dissection, but the rationale for bilateral surgery in patients with unilateral disease on ultrasonography remains unclear.

Objective

To determine the presence of occult contralateral disease (lesions not seen on preoperative ultrasonography) in patients with MTC as a rationale for total thyroidectomy.

Design, Setting, and Participants

This multi-institutional, retrospective cohort study was conducted from September 1998 to April 2022 in academic medical centers and included patients with MTC who underwent thyroidectomy with preoperative imaging.

Main Outcomes and Measures

The primary end point was the prevalence of sonographically occult foci of MTC in the contralateral lobe among patients with sporadic MTC.

Results

The cohort comprised 176 patients with a median age at diagnosis of 55 years (range, 2-87 years), 69 (57.6%) of whom were female. Genetic testing was performed in 109 patients (61.9%), 48 (27.5%) of whom carried germline RET variants. Initial surgical management consisted of total thyroidectomy (161 [91.0%]), lobectomy followed by completion thyroidectomy (7 [4.0%]), and lobectomy alone (8 [4.5%]). Central and lateral neck dissections were performed as part of initial therapy for 146 patients (83.1%). In the entire cohort of 176 patients, 46 (26.0%) had contralateral foci disease and 9 (5.1%) had occult contralateral foci that were not identified on preoperative ultrasonography. Among 109 patients who underwent genetic testing, 38 (34.9%) had contralateral disease, 8 (7.3%) of whom had occult contralateral disease not seen on preoperative ultrasonography. Patients with sporadic MTC experienced a 95.7% reduction in the odds of having a focus of MTC in the contralateral lobe compared with patients with a germline RET variant (odds ratio, 0.043; 95% CI, 0.013-0.123). When adjusting for age, sex, tumor size, and lymph node involvement, the odds ratio of having contralateral MTC in patients with sporadic disease was 0.034 (95% CI, 0.007-0.116). Among patients who underwent lobectomy alone with postoperative calcitonin levels, 5 of 12 (41.7%) achieved undetectable calcitonin levels (<2.0 pg/mL; to convert to pmol/L, multiply by 0.292).

Conclusions and Relevance

The results of this cohort study suggest that a staged approach involving initial thyroid lobectomy could be considered in patients with sporadic MTC and no contralateral ultrasonography findings, with no further surgery if calcitonin levels became undetectable. Further work using prospective randomized clinical trials to evaluate lobectomy as a biochemical cure in patients presenting with unilateral disease is warranted.

Partial preservation of the normal thyroid gland based on tumor diameter may be possible in small medullary thyroid carcinoma: a two-center 15-year retrospective study

Background

At present, there are some controversies in the formulation of surgical protocol for small medullary thyroid carcinoma(s-MTC). We wanted to explore the feasibility of normal thyroid gland retention in small medullary thyroid carcinoma based on different tumor diameters and its prognostic impact on the tumor.

Methods

The data of patients with stage T1 MTC treated at Tianjin Cancer Hospital and Sichuan Cancer Hospital from 2006 to 2021 were analyzed. The tumor diameters of 0.5 cm and 1.0 cm were used as dividing points. The outcomes were tumor recurrence, metastasis, or patient death. Survival was estimated by the Kapan-Meier curve.

Results

A total of 121 T1 s-MTC patients were included, including 55 with total thyroidectomy (TT) and 66 with subthyroidectomy (Sub-TT). There were eleven cases of tumor recurrence and metastasis, and four patients died. When the tumor diameter was 1.0 cm as the cut-off point, tumor diameter (p = 0.010), TT (p = 0.028), unilateral and bilateral type (p = 0.009), and TNM staging (p = 0.007) had significant effects on progression-free survival (PFS). The tumor diameter, unilateral and bilateral type, and TT were risk factors for the prognosis of T1 MTC (p < 0.05).

Conclusion

The tumor diameter of 1.0 cm can be used as a cut-off point for stage T1 MTC. Alt-hough there was no significant difference in overall survival (OS) between T1a and T1b in patients, tumor diameter significantly influenced PFS. TT is not necessary for patients with sporadic MTC with T1a.

A Comparison of Outcomes in Medullary Thyroid Carcinoma Patients With and Without a Preoperative Diagnosis: A Multicenter Retrospective Cohort Study

Background: Cytological limitations pose a challenge to preoperative diagnosis of medullary thyroid carcinoma (MTC) and therefore, a significant subset of patients is only diagnosed postoperatively. The objective of this study was to investigate the impact of knowledge of a preoperative MTC diagnosis on disease management and outcomes. Methods: Multicenter, retrospective, cohort study of MTC patients treated in Israel from January 2000 to June 2021. We compared cohorts of patients according to the presence or absence of a preoperative MTC diagnosis. Results: Ninety-four patients with histologically confirmed MTC were included (mean age 56.2 ± 14.3 years, 43% males). Fifty-three patients (56%) had a preoperative MTC diagnosis (preop-Dx group), and 41 (44%) were confirmed only postoperatively (no-Dx group). The extent of surgical resection, including completion procedures, was as follows: total thyroidectomy in 83% versus 100% (p = 0.002), central lymph node dissection (LND) in 46% versus 98% (p < 0.001), ipsilateral lateral LND in 36% versus 79% (p < 0.001), and contralateral lateral LND in 17% versus 28% (NS), in the no-Dx versus the preop-Dx group, respectively. Pathology confirmed a smaller median tumor size of 16 ± 17.4 mm versus 23 ± 14.0 mm (p = 0.09), a higher proportion of micro-MTC (size ≤10 mm) 32% versus 15% (p = 0.03), and a higher rate of co-occurrence of follicular cell-derived carcinoma 24% versus 4% (p = 0.003), in the no-Dx compared to the preop-Dx group, respectively. The rates of extrathyroidal and extranodal tumor extension were not significantly different between the groups. At the last follow-up, the biochemical cure was attained in 55% [CI 0.38-0.71] compared to 64% [CI 0.50-0.77] of the no-Dx and the preop-Dx group, respectively (p = 0.41). After the exclusion of patients with micro-MTC, biochemical cure was more commonly achieved in the preop-Dx group (33% [CI 0.14-0.52] vs. 62% [CI 0.46-0.77], p = 0.04). Preop-Dx patients had improved overall survival compared to the no-Dx group (log-rank p = 0.04) over a median follow-up of 82 months (interquartile range [IQR] 30-153). Conclusions: Preoperatively, the diagnosis of MTC is often missed. An accurate preoperative diagnosis of MTC may enable guideline-concordant surgical treatment and ultimately contribute to an overall survival benefit in MTC patients.

[111In]In-CP04 as a novel cholecystokinin-2 receptor ligand with theranostic potential in patients with progressive or metastatic medullary thyroid cancer: final results of a GRAN-T-MTC Phase I clinical trial

INTRODUCTION

Medullary thyroid cancer (MTC) is a rare malignant tumour of the parafollicular C-cells with an unpredictable clinical course and currently suboptimal diagnostic and therapeutic options, in particular in advanced disease. Overexpression of cholecystokinin-2 receptors (CCK2R) represents a promising avenue to diagnostic imaging and targeted therapy, ideally through a theranostic approach.

MATERIALS AND METHODS

A translational study (GRAN-T-MTC) conducted through a Phase I multicentre clinical trial of the indium-111 labelled CP04 ([¹¹¹In]In-CP04), a CCK2R-seeking ligand was initiated with the goal of developing a theranostic compound. Patients with proven advanced/metastatic MTC or short calcitonin doubling time were enrolled. A two-step concept was developed through the use of low- and high-peptide mass (10 and 50 μg, respectively) for safety assessment, with the higher peptide mass considered appropriate for therapeutic application. Gelofusine was co-infused in a randomized fashion in the second step for the evaluation of potential reduction of the absorbed dose to the kidneys. Imaging for the purpose of biodistribution, dosimetry evaluation, and diagnostic assessment were performed as well as pre-, peri-, and postprocedural clinical and biochemical assessment.

RESULTS

Sixteen patients were enrolled. No serious adverse events after application of the compound at both peptide amounts were witnessed; transient tachycardia and flushing were observed in two patients. No changes in biochemistry and clinical status were observed on follow-up. Preliminary dosimetry assessment revealed the highest dose to urinary bladder, followed by the kidneys and stomach wall. The effective dose for 200 MBq of [¹¹¹In]In-CP04 was estimated at 7±3 mSv and 7±1 mSv for 10 μg and 50 μg CP04, respectively. Administration of Gelofusine reduced the dose to the kidneys by 53%, resulting in the organ absorbed dose of 0.044±0.019 mSv/MBq. Projected absorbed dose to the kidneys with the use of [¹⁷⁷Lu]Lu-CP04 was estimated at 0.9±0.4 Gy/7.4 GBq. [¹¹¹In]In-CP04 scintigraphy was positive in 13 patients (detection rate of 81%) with superior diagnostic performance over conventional imaging.

CONCLUSION

In the present study, [¹¹¹In]In-CP04 was shown to be a safe and effective radiopharmaceutical with promising theranostic characteristics for patients with advanced MTC.

Total thyroidectomy vs thyroid lobectomy for localized medullary thyroid cancer in adults: A propensity-matched survival analysis

BACKGROUND

This study aimed to clarify whether the extent of thyroidectomy (total thyroidectomy vs thyroid lobectomy) influences survival in adults with localized medullary thyroid cancer.

METHODS

Patients with localized medullary thyroid cancer were identified using the Surveillance, Epidemiology, and End Results database (2000-2018). An independent cohort of patients with localized medullary thyroid cancer were retrospectively reviewed from three medical centers in China from 2010 to 2020. The patients were grouped by the extent of surgery (total thyroidectomy vs thyroid lobectomy). Primary end points were overall survival and disease-specific survival.

RESULTS

From 1,686 patients with medullary thyroid cancer identified in SEER, 1,122 patients met inclusion for matching, with a median follow-up of 99 months. After propensity score matching, 122 patients underwent a total thyroidectomy and 122 patients underwent a thyroid lobectomy. The 10-year overall survival was 85.2% (77.9%-90.7%) and 83.1% (75.5%-90.7%) in total thyroidectomy group and in thyroid lobectomy group, respectively. The 10-year disease-specific survival was 100% and 96.8% (93.1%-100%) in total thyroidectomy group and in thyroid lobectomy group, respectively. There was no statistically significant difference in overall survival or disease-specific survival in patients with localized medullary thyroid cancer undergoing total thyroidectomy or thyroid lobectomy (hazard ratio = 0.83, 95% confidence interval 0.44-1.57, P = .57 and hazard ratio = 0.49, 95% confidence interval 0.10-2.41, P = .39, respectively). Forty-seven patients with localized medullary thyroid cancer were identified in an independent Chinese cohort (n = 29 in total thyroidectomy group vs n = 18 in thyroid lobectomy group). After a median follow-up of 47 months, there was no mortality observed in either group.

CONCLUSION

This study suggests that the extent of thyroidectomy does not influence survival for patients with early-stage localized medullary thyroid cancer and that thyroid lobectomy might be adequate in this patient population.

Incidental T1 stage medullary thyroid carcinoma: The effect of tumour diameter on prognosis and therapeutic implications

OBJECTIVE

The definition of the tumour diameter of micro-medullary thyroid carcinoma (micro-MTC) is insufficient. It is controversial to perform a completion thyroidectomy immediately for incidental T1 stage MTC.

DESIGN

We used the Surveillance, Epidemiology and End Results (SEER) registry to retrospectively analyze all patients with T1 stage MTC diagnosed between 2004 and 2015. The tumour diameter 1.0 and 0.5 cm were used as the cut-off points to group and analyze the differences of clinicopathological features. We analyzed the prognosis of patients with less than total thyroidectomy.

METHODS

The disease-specific survival was the main outcome. Survival was estimated with Kaplan-Meier curves and Cox regression models estimated hazard ratios for tumour characteristics.

RESULTS

A total of 908 patients diagnosed with T1 stage MTC in the SEER database were included. Our study found that tumour diameter 1.0 cm is a key point affecting the prognosis of T1 stage MTC patients, although patients with tumour diameter ≤ 0.5 cm had a lower rate of lymph node metastasis and no distant metastasis. Cox proportional hazard multivariate analysis showed that distant metastasis was the only risk factor for survival in patients with T1 stage MTC. Kaplan-Meier survival analysis showed that, regardless of tumour diameter, there was no significant difference between less than total thyroidectomy and total thyroidectomy in T1 stage patients.

CONCLUSIONS

For incidental MTC with tumour diameter ≤ 1.0 cm and without distant metastasis, if there is no significant increase in serum calcitonin level after surgery and ret proto-oncogene (RET) gene mutation is negative, it may be not necessary to perform completion thyroidectomy immediately.

Clinical Characteristics, Surgical Management, and Prognostic Factors of Medullary Thyroid Carcinoma: A Retrospective, Single-Center Study

Purpose: Medullary thyroid carcinoma (MTC) is a rare neuroendocrine malignancy with relatively early lymphatic metastatic spread. The clinical features of MTC remain controversial owing to the low incidence rate. This study aimed to analyze the clinical characteristics, prognostic factors, and long-term follow-up of MTC. Methods: Medical records of MTC patients treated at our hospital between December 2000 and November 2020 were reviewed retrospectively. Clinicopathologic features of MTC were analyzed using univariate and multivariate analyses. Cumulative survival rates were estimated using the Kaplan-Meier method. Results: In total, 152 patients with MTC were included. The rates of central and lateral lymph node metastases (LNM) were 52.0% and 42.8%, respectively. All patients were followed up with a median follow-up time of 43.5 (17.0−76.3) months. Univariate and multivariate analyses identified two independent factors associated with progressive disease. They were lateral LNM (p < 0.001) and lymph node ratio (LNR) >1/3 (p = 0.009). The 5-, 10-, and 15-year cumulative overall survival (OS) rates of MTC were 88.2%, 83.1%, and 76.2%, respectively. The 5-, 10-, and 15-year cumulative disease-free survival (DFS) rates were 61.8%, 48.6%, and 38.2%, respectively. Patients with stage I, II, and III disease had significantly longer OS and DFS than those with stage IV disease (p < 0.001). Conclusion: MTC is a rare endocrine malignancy and LNM is common. Patients with lateral LNM and LNR >1/3 are more likely to develop progressive disease. The long-term OS rates of MTC are good, but long-term DFS rates are poor.

Unilateral Surgery for Medullary Thyroid Carcinoma: Seeking for Clinical Practice Guidelines

Optimized preoperative diagnostic tools with calcitonin tests, ultrasound features, functional imaging modalities, and genetic testing to detect hereditary forms have led to an increased rate of earlier diagnosis and surgery for medullary thyroid cancer (MTC). This helps to adapt the primary surgery to the tumor stage and avoid surgical overtreatment for localized tumor growth, i.e., deviating from the regularly recommended thyroidectomy with bilateral central lymph node dissection in favor of a limited unilateral approach. To limit primary surgical therapy, it is crucial that the MTC is clinically unifocal, sporadic, and confined to the thyroid, and that calcitonin levels indicate biochemical recovery after surgery. The main requirement for such a limited approach is the availability of frozen section studies that reliably indicate (i) R0 resection of the MTC, (ii) absence of infiltration of the organ capsule, (iii) lack of desmoplasia (i.e., evidence of the metastatic potential of the MTC), (iiii) absence of contralateral disease or precancerous lesions. Informed consent is mandatory from the patient, who has been fully informed of the advantages, disadvantages, and potential risks of not undergoing the "classic" surgical procedure. The aim of this article is to review the guidelines for the management of early-stage MTC.

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.

[Extent of resection in intrathyroidal medullary thyroid cancer]

Improvements in preoperative diagnostic modalities in conjunction with highly sensitive calcitonin assays, ultrasound and functional imaging modalities and differentiated genetic testing for detection of hereditary forms, have enabled detection and resection of medullary thyroid carcinoma at an increasingly earlier stage. These developments open up possibilities to deescalate primary surgery adapted to these stages and avoid surgical overtreatment in locally limited tumor growth: thus, promoting a shift from routinely recommended total thyroidectomy with bilateral central lymph node dissection in favor of limited unilateral thyroid resection. Prerequisites for limited thyroid resection include clinical evidence that the tumor is sporadic, unifocal and confined to the thyroid. Corresponding calcitonin levels should also indicate that a biochemical cure will be achieved after unilateral resection. A decisive structural prerequisite for such a limited concept is the low threshold availability of intraoperative frozen section analysis that reliably detects and evaluates a medullary thyroid carcinoma and can assess a breach of the thyroid capsule and desmoplasia with certainty.

Controversies in the surgical management of sporadic medullary thyroid carcinoma

PURPOSE OF REVIEW

Medullary thyroid carcinoma (MTC) represents a wide spectrum of tumours with differing biology, behaviour and natural history. The only current available curative treatment is surgery in the form of thyroidectomy with or without ipsilateral or bilateral neck dissection. There is a lack of consensus in the available published guidelines on the optimum extent of initial surgery, and there is significant variation in clinical practice. This review focuses on the most recently published evidence.

RECENT FINDINGS

Many patients with limited disease do not receive total thyroidectomy and central neck compartment dissection as recommended by international guidelines. Despite this, 5-year disease-specific survival is over 90% in those without distant metastases at presentation. Over 20% of patients may harbour occult lateral compartment nodal metastases, and baseline calcitonin alone (>1000 pg/ml) is not a good predictor of nodal metastasis. Although delayed lateral neck compartment dissection results in similar survival outcomes to prophylactic neck dissection for clinically node-negative patients, there is an underappreciated psychological effect of having biochemical evidence of persistent disease following limited surgery.

SUMMARY

No single currently available prognostic indicator is sufficient to predict disease behaviour and evidence of occult nodal metastases. In clinically ad radiologically node-negative patients, the extent of neck dissection at initial operation, therefore, needs to be planned and executed on an individual patient basis.

Long-Term Outcomes and Aggressiveness of Hereditary Medullary Thyroid Carcinoma: 40 Years of Experience at One Center

CONTEXT

Recent data on long-term outcomes and aggressiveness of medullary thyroid carcinoma (MTC) are lacking for patients with multiple endocrine neoplasia type 2 (MEN2).

OBJECTIVES

To analyze the long-term outcomes in MEN2 and compare MTC aggressiveness in three defined RET mutation-risk categories: moderate risk (MOD), high risk (H), and highest risk (HST).

DESIGN, SETTING

Retrospective study of 263 operated patients with MEN2 from one German tertiary referral center from 1979 to 2017 comparing demographic, biochemical, genetic, and outcome parameters.

INTERVENTION

None (observational study).

MAIN OUTCOME MEASURE

Long-term survival and outcomes in three risk groups.

RESULTS

Surgery was performed at a mean age of 35.3 ± 18.8 (MOD, n = 122), 23.0 ± 15.7 years (H, n = 120), and 14.9 ± 9.3 (HST, n = 21) years (P < 0.05). The mean follow-up was 12.9 ± 9.8 years. Age and tumor stage at diagnosis differed among the three risk groups (P < 0.0001). Multivariate analysis of disease-specific survival (DSS) showed that increasing age [hazard ratio (HR), 1.06; 95% CI, 1.02 to 1.09], stage III/IV at diagnosis (HR, 7.39; 95% CI, 2.39 to 22.8), and HST group (HR, 14.4; 95% CI, 3.32 to 62.6) were significantly associated with worse DSS; the H group was not (P = 0.175). The DSS rates and outcomes were not different between the MOD and H groups (P = 0.179 and P = 0.893, respectively) but were significantly inferior in the HST group (P < 0.0008 and P < 0.0001, respectively).

CONCLUSION

MTC in patients with MEN2 showed a clearly different age of onset in the different risk groups. DSS and outcomes after MTC diagnosis were similar in the MOD and H groups, suggesting similar tumor behavior. The HST group had inferior outcomes and survival vs the MOD and or H groups.

Development and validation of prognostic nomograms for medullary thyroid cancer

Background

This aim of study was to develop and validate clinical nomograms to predict the survival of patients with medullary thyroid cancer.

Patients and methods

Patient data were collected from the Surveillance, Epidemiology, and End Results database between 2004 and 2013. All included patients were randomly assigned into the training and validation sets. Multivariate analysis using Cox proportional hazards regression was performed, and nomograms were constructed. Model performance was evaluated by discrimination and calibration plots.

Results

A total of 1,657 patients were retrospectively analyzed. The multivariate Cox model identified age, tumor size, extrathyroidal extension, N stage, and M stage as independent covariates associated with overall survival (OS) and cancer-specific survival (CSS). Nomograms predicting OS and CSS were constructed based on these covariates. The nomograms predicting both OS and CSS exhibited superior discrimination power to that of TNM staging system in the training and validation sets. Calibration plots indicated that both the nomograms in OS and CSS exhibited high correlation to actual observed results.

Conclusion

The nomograms established in this study provided an alternative tool for prognostic prediction, which may thereby improve individualized assessment of survival risks and lead to the creation of additional clinical therapies.

Survival and Long-Term Biochemical Cure in Medullary Thyroid Carcinoma in Denmark 1997-2014: A Nationwide Study

BACKGROUND

Survival of medullary thyroid carcinoma (MTC) subgroups in relation to the general population is poorly described. Data on the factors predicting long-term biochemical cure in MTC patients are nonexistent at a population level. A nationwide retrospective cohort study of MTC in Denmark from 1997 to 2014 was conducted, aiming to detect subgroups with survival similar to that of the general population and to identify prognostic factors for disease-specific survival and long-term biochemical cure.

METHODS

The study included 220 patients identified from the nationwide Danish MTC cohort between 1997 and 2014. As a representative sample of the general population, a reference population matched 50:1 to the MTC cohort was used.

RESULTS

Patients diagnosed with hereditary MTC by screening (hazard ratio [HR] = 1.5 [confidence interval (CI) 0.5-4.3]), patients without regional metastases (HR = 1.4 [CI 0.9-2.3]), and patients with stage I (HR = 1.3 [CI 0.6-3.1]), stage II (HR = 1.1 [CI 0.6-2.3]), and III (HR = 1.3 [CI 0.4-4.2]) disease had an overall survival similar to the reference population. On multivariate analysis, the presence of distant metastases (HR = 12.3 [CI 6.0-25.0]) predicted worse disease-specific survival, while the absence of regional lymph node metastases (odds ratio = 40.1 [CI 12.0-133.7]) was the only independent prognostic factor for long-term biochemical cure.

CONCLUSIONS

Patients with hereditary MTC diagnosed by screening, patients without regional metastases, and patients with stages I, II, and III disease may have similar survival as the general population. The presence of distant metastases predicted worse disease-specific survival, while the absence of regional metastases predicted long-term biochemical cure.