Recent advances in the surgical treatment of differentiated thyroid cancer: a comprehensive review

Comparison of thyroid surgery techniques: a retrospective cohort study and meta-analysis of traditional electric knife vs. straight bipolar electrocoagulation forceps

Background

In recent years, advancements in surgical techniques for thyroidectomy have led to varying outcomes and efficiencies. Understanding these differences is crucial to optimize patient care and surgical success. This study compared intra- and postoperative parameters of thyroid surgery for thyroidectomy or thyroid cancer. One approach involved the traditional electric knife, employing traditional clamp-ligation skills and an electric knife. The other approach utilized straight bipolar electrocoagulation forceps for micro-hemostasis and micro-cutting.

Methods

Data were analyzed retrospectively for 228 patients who underwent thyroidectomy at the Third Affiliated Hospital of Kunming Medical University from January 2014 to November 2018. Surgery was performed either as traditional open surgery (n=150) or as a meticulous anatomical procedure involving bipolar electrocoagulation (n=78). In addition, data from published studies comparing the two surgical procedures were meta-analyzed.

Results

The bipolar electrocoagulation procedure was associated with significantly shorter total operation time, lower intraoperative blood loss and lower rate of hypocalcemia. The two procedures were associated with similar rates of hoarseness. Meta-analysis of eight studies involving 2,080 patients showed that bipolar electrocoagulation was associated with significantly shorter total operation time than the traditional approach (mean difference =-21.29 min, 95% CI: -26.32 to -16.27) and with less intraoperative bleeding (mean difference =-12.87 min, 95% CI: -23.81 to -1.93).

Conclusions

Straight bipolar electrocoagulation forceps can be used to perform fine dissection during thyroid surgery. Performing "micro-hemostasis" and "micro-cutting" manipulations with these straight bipolar forceps can smoothly dissect nerves and parathyroid glands and may reduce intraoperative bleeding, operation time and rates of postoperative complications, might accelerate recovery after surgery.

Nomogram individually predicts the risk for distant metastasis and prognosis value in female differentiated thyroid cancer patients: A SEER-based study

Objective

Distant metastasis (DM) is an important prognostic factor in differentiated thyroid cancer (DTC) and determines the course of treatment. This study aimed to establish a predictive nomogram model that could individually estimate the risk of DM and analyze the prognosis of female DTC patients (FDTCs).

Materials and methods

A total of 26,998 FDTCs were retrospectively searched from the Surveillance, Epidemiology, and End Results (SEER) database from 2010 to 2018 and randomly divided into validation and training cohorts. Univariate and multivariate analyses were performed to screen for prognostic factors and construct a prediction nomogram. The performance of the nomogram was assessed by the area under the receiver operating characteristic curve (AUC), concordance index (C-index), and a calibration curve. The overall survival (OS) and cancer-specific survival (CSS) were evaluated by Kaplan-Meier (K-M) analysis.

Results

A total of 263 (0.97%) FDTCs were reported to have DM. K-M analysis showed the association of multiple-organ metastases and brain involvement with lower survival rates (P < 0.001) in patients. Tumor size, age at diagnosis, thyroidectomy, N1 stage, T3-4 stage, and pathological type were independent predictive factors of DM in FDTCs (all P < 0.001). Similarly, age at diagnosis, Black, DM, T3-4 stage, thyroidectomy, and lung metastasis were determined as independent prognostic factors for FDTCs (all P < 0.001). Several predictive nomograms were established based on the above factors. The C-index, AUC, and calibration curves demonstrated a good performance of these nomogram models.

Conclusion

Our study was successful in establishing and validating nomograms that could predict DM, as well as CSS and OS in individual patients with FDTC based on a large study cohort. These nomograms could enable surgeons to perform individualized survival evaluation and risk stratification for FDTCs.

Synergic effects of histology subtype, lymph node metastasis, and distant metastasis on prognosis in differentiated thyroid carcinoma using the SEER database

Background

Differentiated thyroid carcinoma (DTC) is the most common clinical type of thyroid carcinoma. There are rare reports on the synergic effects of the different clinicopathological risk factors on the prognosis of it.

Methods

We retrospectively reviewed data on 86,032 DTC patients from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate Cox regression analyses were conducted to evaluate the correlation between clinicopathological factors and the prognosis of DTC. Relative excess risk (RERI) of synergic effect, attributable proportion (AP) of synergic effect, and synergy index (SI) were calculated to assess synergic effects. Kaplan-Meier analyses with log-rank tests was used to plot the survival curve affected by different risk factors.

Results

Histology subtype, lymph node metastasis (LNM) status, and distant metastasis (DM) were independent risk factors for cancer-specific survival (CSS) and all-cause survival (ACS) in the multivariate analysis (all, P<0.001). Patients' age at diagnosis, sex, extrathyroidal extension, and radiation also influenced prognosis (all, P<0.001). The cancer-specific mortality (CSM) and all-cause mortality (ACM) rates per 1,000 person-years were higher in patients with follicular thyroid carcinoma (FTC) and in those with N1 stage and M1 stage disease. Furthermore, we observed a significant synergic effect between histology subtype and N stage, as well as histology subtype and M stage for the CSM of DTC (RERI =48.806, AP =0.853, SI =7.565; RERI =37.889, AP =0.430, SI =1.771, respectively). However, no synergic effect was observed in the case of the N stage and M stage for the CSM of DTC (RERI =7.928, AP =0.084, SI =1.093).

Conclusions

Patients with histology subtype of FTC and N1 stage, histology subtype of FTC and M1 stage had significant additive synergic effects on DTC prognosis for CSM.

Prophylactic lymph node dissection in clinically N0 differentiated thyroid carcinoma: example of personalized treatment

Considering the 'differentiated thyroid carcinoma (DTC) epidemic', the indolent nature of DTC imposes a treatment paradigm shift toward elimination of recurrence. Lymph node metastases in cervical compartments, encountered in 20-90% of DTC, are the main culprit of recurrent disease, affecting 5-30% of patients. Personalized risk-stratified cervical prophylactic lymph node dissection (PLND) at initial thyroidectomy in DTC with no clinical, sonographic or intraoperative evidence of lymph node metastases (clinically N0) has been advocated, though not unanimously. The present review dissects the controversy over PLND. Weighing the benefit yielded from PLND up against the PLND-related morbidity is so far hampered by the inconsistent profit yielded by PLND and the challenging patient selection. Advances in tailoring PLND are anticipated to empower optimal patient care.

Extracervical Approaches to Thyroid Surgery: Evolution and Review

Over the last two decades, advances and adaptation of technology have led to a variety of endoscopic thyroidectomy procedures being performed. The drive for extracervical procedures has been predominantly influenced by the desire for improved cosmesis via avoidance of visible scars. Extracervical techniques have shown considerable evolution with approaches that have included transaxillary, breast, postauricular, and transoral routes. There has been a varied evidence base for each of these approaches with regard to technical feasibility, safety, patient satisfaction, and cost-effectiveness. In recent years, robotic-assisted thyroid surgery has gained increased popularity worldwide with the introduction of the da Vinci Robot. Reports of improved postoperative outcomes and patient satisfaction have been in contrast to the financial burden, longer operative time, and increased training required which, to date, have limited widespread application. The aim of this review is to describe the evolution of extracervical procedures including surgical approaches, outcomes, advantages, and disadvantages. Consideration is also given to the future direction of extracervical thyroid surgery with regard to the safety, feasibility, and application of robotic systems.

Comparison of the breast and areola approaches for endoscopic thyroidectomy in patients with microcarcinoma

The safety, advantages and disadvantages of thyroidectomy for microcarcinoma through the areola approach and breast approach were compared. Fifty patients diagnosed with thyroid microcarcinoma in our department from January 2014 to June 2015 were selected. The areola approach was carried out for 21 patients whereas the breast approach for 29 patients. Endoscopic thyroid lobectomy, isthmus resection and dissection of central group lymph nodes was performed. The clinical outcomes of the two surgical approaches were compared. Comparing operating time, blood loss during surgery, number of lymph node dissections, postoperative hospitalization time and surgical complications between the surgical approaches, there were no significant differences (P>0.05). Comparing patient satisfaction of cosmetic results from the incisions, the difference was statistically significant (P<0.05). Endoscopic thyroidectomy via areola approach and breast approach have equal curative effects for the treatment of thyroid microcarcinoma. However, the areola approach can achieve better cosmetic results and is a safe and ideal surgical method, that we recommend be widely used.

Revisiting the transcriptional analysis of primary tumours and associated nodal metastases with enhanced biological and statistical controls: application to thyroid cancer

Background:

Transcriptome profiling has helped characterise nodal spread. The interpretation of these data, however, is not without ambiguities.

Methods:

We profiled the transcriptomes of papillary thyroid cancer nodal metastases, associated primary tumours and primary tumours from N0 patients. We also included patient-matched non-cancerous thyroid and lymph node samples as controls to address some limits of previous studies.

Results:

The transcriptomes of patient-matched primary tumours and metastases were more similar than those of unrelated metastases/primary pairs, as previously reported in other organ systems. This similarity partly reflected patient background. Lymphoid tissues in the metastases confounded the comparison of patient-matched primary tumours and metastases. We circumvented this with an original data adjustment, revealing a differential expression of stroma-related gene signatures also regulated in other organs. The comparison of N0 vs N+ primary tumours uncovered a signal irreproducible across independent data sets. This signal was also detectable when comparing the non-cancerous thyroid tissues adjacent to N0 and N+ tumours, suggesting a cohort-specific bias also likely present in previous similarly sized studies. Classification of N0 vs N+ yielded an accuracy of 63%, but additional statistical controls absent in previous studies revealed that this is explainable by chance alone. We used large data sets from The Cancer Genome Atlas: N0 vs N+ classification was not better than random for most cancers. Yet, it was significant, but of limited accuracy (<70%) for thyroid, breast and head and neck cancers.

Conclusions:

The clinical potential of gene expression to predict nodal metastases seems limited for most cancers.

Management of differentiated thyroid carcinoma with bone metastasis: a case report and review of the Chinese literature

Differentiated thyroid carcinoma (DTC) is a common malignancy. The general treatments are thyroidectomy of the affected lobe along with lymphadenectomy. However, bone metastasis is rare in DTC compared with other malignancies and the management of metastasis foci is still controversial. Here we present a case of follicular thyroid carcinoma with the 6th cervical vertebra body metastasis successfully treated by total thyroidectomy, cervical corpectomy, and internal fixation, followed by hormone replacement therapy and radioiodine therapy. Eleven additional patients diagnosed as thyroid carcinoma with bone metastasis collected from Chinese literature between January 1996 and December 2013 were also reviewed. The mean age of the 12 patients at presentation was (53.9±9.2) years (rang, 42-72 years) and the male to female ratio was 1:2. Nine cases received total/near-total thyroidectomy or lobectomy while the other three patients refused for personal reasons. The interventions for bone metastasis were one-stage operation (9/12), I(131) adjuvant therapy (3/12), chemotherapy (1/12), and no intervention (1/12). During the follow-up, two patients died of metastatic carcinoma recurrence, one died of multiple organ metastasis, and one with an unknown reason. We conclude that the management of thyroid carcinoma with bone metastasis needs multidisciplinary cooperation. Surgical resection is still the first choice for cure, while the combined one-stage operation on the primary and metastatic sites followed by hormone replacement therapy and radioiodine therapy is an applicable treatment.

Prognostic factors affecting disease-specific survival in patients with recurrent and/or metastatic differentiated thyroid carcinoma detected by positron emission tomography/computed tomography

AIM

We aimed to analyze the prognostic factors affecting disease-specific survival in patients with recurrent and/or metastatic differentiated thyroid carcinoma.

METHODS

Seventy-seven patients with recurrent/metastatic differentiated thyroid carcinoma who were previously treated with total thyroidectomy followed by radioactive iodine therapy were enrolled. Recurrent/metastatic disease was detected by positron emission tomography/computed tomography. At the time of last follow-up (mean 4.8±1.3 years), patients were grouped as having (i) clinical remission (n=17), (ii) stable disease (n=22), or (iii) progressive disease (n=38). We retrospectively examined the prognostic impact of clinical factors (age, sex, TNM stage), histopathological factors of the primary tumor (tumor size, histology, the presence of vascular invasion, extrathyroidal spread, and lymph node metastasis), serum thyroglobulin levels, and metabolic parameters of recurrent/metastatic disease such as radioactive iodine avidity, F18-fluorodeoxyglucose uptake (SUVmax) in metastatic deposits, number and location of F18-fluorodeoxyglucose-avid lesions (locoregional vs. distant), and the impact of surgery on disease-specific survival.

RESULTS

Lack of vascular invasion (p=0.04), presence of surgically amenable recurrence/metastasis (p=0.0001), and suppressible on-therapy serum thyroglobulin levels at the time of recurrent/metastatic disease (p=0.01) were strong predictors of clinical remission and good prognosis on multivariate analysis. Lesional SUVmax, number or location of F18-fluorodeoxyglucose-avid lesions, and TNM stage did not correlate with clinical outcome. Clinical remission could only be achieved by curative surgery. Patients without curative surgery for recurrence/metastasis had a 43 times higher risk to develop progressive disease than patients with disease amenable to surgery.

CONCLUSIONS

Curative surgery is an essential therapeutic modality to achieve clinical remission in metastatic/recurrent differentiated thyroid carcinoma. Positron emission tomography/computed tomography is a powerful method to detect surgically resectable disease for the selection of patients who may benefit from curative surgery.