Analysis of risk factors and prognosis in differentiated thyroid cancer with focus on minimal extrathyroidal extension

Minimal Extrathyroid Extension (mETE) as the Only Risk Factor in Patients with Papillary Thyroid Carcinoma (PC): Its Clinical Impact on Recurrence and Outcome during Long-Term Follow-Up

Minimal extrathyroid extension (mETE) effect on papillary thyroid carcinoma (PC) prognosis is still debated even more so now that this factor has been removed in the 8th AJCC Edition, supporting the hypothesis that mETE is not associated with aggressive tumors. We retrospectively enrolled 91 PC patients (Group 1) submitted to total thyroidectomy and radioiodine ablation. At the time of the primary tumor surgery, mETE was ascertained in all patients with no other risk factors, such as multifocality, vascular invasion, neck and distant metastases, and aggressive histological variants. As controls, 205 consecutive matched PC patients (Group 2) without mETE and the aforementioned risk factors were enrolled. During the follow-up (average 8 years), 16/91 (17.58%) Group 1 patients and 15/205 (7.32%) Group 2 patients developed metastases (p = 0.0078). Cox regression analysis showed an increased risk of metastases in patients with mETE (HR: 2.58 (95% CI 1.28-5.22) p = 0.008). Disease-free survival (DFS) was significantly lower in patients with mETE than in controls (p = 0.0059). The present study seems to demonstrate that mETE can be associated with an aggressive PC and can be considered, even alone without other risk factors, an independent factor of unfavorable DFS. Thus, by excluding mETE in the 8th AJCC Edition, patient care and management could be compromised.

Course and predictors of excellent response to therapy in patients with differentiated thyroid cancer at long-term follow-up

OBJECTIVES

To investigate the long-term outcomes of differentiated thyroid cancer (DTC) and the predictive factors for excellent and incomplete responses to therapy on long-term follow-up of patients.

METHODS

A retrospective chart review and analysis was carried out at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Demographic, histological, and therapeutic data were collected from patients older than 13 years at the time of diagnosis, with a minimum follow-up of 18 months. Outcomes were divided into excellent, indeterminate, biochemically incomplete, and structurally incomplete responses. Odds ratios (ORs) for predictors of incomplete response at the last visit were determined. We first tested associations univariately with incomplete responses, and then variables with significant associations were included in a multivariable logistic model.

RESULTS

Among 230 patients with DTC, 61.7% had excellent responses to therapy on long-term follow-up, and 24.3% had incomplete biochemical and structural responses. The median follow-up was 4.6 years. Factors significantly associated with incomplete response to therapy in the multivariate analysis (p<0.05) were age >55 years (OR=5) and lymph node (OR=3.4) and distant metastases (OR=29). Older age did not affect the outcome in low-risk patients with DTC but was significantly associated with incomplete responses in those with intermediate risk (p=0.04) and high risk (p=0.003).

CONCLUSION

We strongly advocate incorporating age into recurrence risk assessment for patients with DTC.

Correlation research between preoperative ultrasonographic features and postoperative recurrence of papillary thyroid carcinoma: a retrospective study

OBJECTIVE

This study sought to evaluate the risk factors for recurrent papillary thyroid carcinoma by preoperative ultrasonography.

METHODS

A retrospective study enrolled a total of 146 patients with thyroid papillary carcinoma confirmed by postoperative pathology, and divided into a recurrence group (n = 35) and a non-recurrence group (n = 111) to study their preoperative ultrasound report examination, including the presence of thyroiditis, tumor location, the maximum diameter of the primary tumor, tumor number, the presence of focal strong echogenicity within the lesion, the presence of abnormal lymph nodes, the presence of ultrasound imaging manifestations of thyroid invasion, and to explore the risk factors associated with recurrent papillary thyroid cancer. Moreover, the consistency of ultrasound examination and postoperative pathological findings was explored.

RESULTS

There were significant differences in the maximum diameter of the primary tumor and thyroid invasion between the recurrent and non-recurrent papillary thyroid carcinoma groups (P < 0.05), and the preoperative tumor diameter diagnostic cutoff value is 13.750 mm. At the same time, ultrasound and pathology have good consistency in the number of papillary thyroid carcinoma tumors, moderate consistency in lymph node metastasis, and excellent consistency in the presence or absence of thyroid invasion.

CONCLUSIONS

The maximum diameter of the primary tumor and thyroid invasion can be used as indicators to evaluate the risk of recurrence of thyroid papillary carcinoma by ultrasonic examination. In addition, the number of tumors and the presence of thyroid invasion in ultrasonic and pathological diagnosis showed good consistency.

Lobo-isthmectomy in the management of differentiated thyroid cancer

We have recently witnessed a rapid increase in the incidence of differentiated thyroid carcinoma (DTC), particularly low and very low-risk papillary thyroid carcinoma. Simultaneously, the number of cancer-related deaths has remained stable for more than 30 years. Such an indolent nature and long-term survival prompted researchers and experts to an ongoing discussion on the adequacy of DTC management to avoid, on the one hand, the overtreatment of low-risk cases and, on the other hand, the undertreatment of highly aggressive ones.The most recent guidelines of the American Thyroid Association (ATA GL) moved primary thyroid surgery in DTC towards a less aggressive approach by making lobectomy an option for patients with intrathyroidal low-risk DTC tumors up to 4 cm in diameter without evidence of extrathyroidal extension or lymph node metastases. It was one of the key changes in DTC management proposed by the ATA in 2015.Following the introduction of the 2015 ATA GL, the role of thyroid lobectomy in DTC management has slowly become increasingly important. The data coming from analyses of the large databases and retrospective studies prove that a less extensive surgical approach, even if in some reports it was related to a slight increase of the risk of recurrence, did not show a negative impact on disease-specific and overall survival in T1T2N0M0 low-risk DTC. There is no doubt that making thyroid lobectomy an option for low-risk papillary and follicular carcinomas was an essential step toward the de-escalation of treatment in thyroid carcinoma.This review summarizes the current recommendations and evidence-based data supporting the necessity of de-escalation of primary thyroid surgery in low-risk DTC. It also discusses the controversies raised by introducing new ATA guidelines and tries to resolve some open questions.

Prognostic Impact of Microscopic Extra-Thyroidal Extension (mETE) on Disease Free Survival in Patients with Papillary Thyroid Carcinoma (PTC)

Background: This study assessed the risk of reduced disease-free survival (DFS) and poor clinical outcome in patients with papillary thyroid carcinomas (PTC) with microscopic extra-thyroidal extension (mETE), as compared to PTC patients without mETE. Methods: Retrospective analysis of a prospective database of patients treated by total thyroidectomy and radioactive iodine (RAI) with a five-year follow-up and tumors < 40 mm. In total, 303 patients were analyzed: 30.7% presented tumors with mETE, and 69.3% without. mETE was defined as extra-thyroidal invasion without skeletal muscle involvement. The primary outcome, DFS, was defined as the interval between initial treatment and any subsequent PTC-related treatment. The second outcome was the clinical status at five years. Results: In univariate analyses, the five-year DFS was significantly lower for tumors with mETE (62.4% versus 88.1%, p < 0.001). In multivariate analysis, mETE and massive lymph node involvement (LNI) were independent prognostic factors, associated respectively with a hazard ratio of 2.55 (95% CI 1.48−4.40) and 8.94 (95% CI 4.92−16.26). mETE was significantly associated with a pejorative clinical outcome at five years, i.e., biochemical/indeterminate response and structural persistence (Respectively OR 1.83 (95% CI 0.83; 4.06) and OR 4.92 (95% CI 1.87; 12.97)). Conclusion: Our results suggest that mETE is an independent poor prognosis factor of reduced DFS and predictive of poor clinical outcome.