Prognosis of well Differentiated Thyroid Carcinoma Associated with Hyperthyroidism

Research Article

Annals Thyroid Res. 2024; 10(1): 1092.

Prognosis of well Differentiated Thyroid Carcinoma Associated with Hyperthyroidism

Bassam Abboud, MD*; Christopher Abboud, MD

Division of General Surgery, Geitaoui Hospital, Faculty of Medicine, Lebanese University, Beirut, Lebanon

*Corresponding author: Bassam ABBOUD MD Division of General Surgery, Geitaoui Hospital, Achrafieh, Beirut, Lebanon. Tel: 961 1 590000; Fax: 961 1 511911 Email: dbabboud@yahoo.fr

Received: December 21, 2023 Accepted: February 02, 2024 Published: February 08, 2024

Abstract

Backgrounds: This paper aim to report prognosis of well differentiated thyroid carcinoma associated with hyperthyroidism: Grave’s disease, toxic multinodualr goiter, and toxic uninodular goiter.

Methods: The medical records of all consecutive patients who underwent surgery for hyperthyroidism were retrospectively reviewed with regard to patient demographics, clinical presentation, preoperative biological and imaging findings, surgery, pathology and follow-up records.

Results: 11% presented hyperthyroidism with well differentiated thyroid carcinoma. Papillary thyroid carcinoma being the most common histological type. Papillary microcarcinoma, multifocality, bilaterality, and recurrence was more associated with Grave’s disease. Extrathyroid extension, and positive lymph nodes were more showed in toxic multinodualr goiter. We noted 3 differences (size of the nodules, recurrence, and presence of distant metastases) without reaching statistically significance in the characteristics and prognosis of well differentiated thyroid carcinoma in euthyroid patients compared to hyperthyroid patients.

Conclusion: Well differentiated thyroid carcinoma was more associated Grave’s disease. We did not show any statistically significance difference of well differentiated thyroid carcinoma in euthyroid patients compared to hyperthyroid patients.

Keywords: Euthyroidism; Hyperthyroidism; Thyroid carcinoma; Surgery; Prognosis

Introduction

The prevalence of thyroid carcinomas found during surgery in hyperthyroid patients is reported to vary widely, ranging up to 21.1 % [1-17]. Thyroid cancer is typically present with euthyroid or clinical/subclinical hypothyroidism. Thyrotoxicosis with suppressed TSH should lead to a lower incidence of thyroid cancer than that observed in euthyroid patients. Although all histological types of thyroid carcinomas can be associated with hyperthyroidism, the most frequently reported type is Papillary Thyroid Carcinoma (PTC) [1,6,18-32]. Some studies reported that thyroid cancer is diagnosed more frequently in patients with Graves’ Disease (GD) [28-39] than in patients with Toxic Uninodular Goiter (TUG) [40-52] or Toxic Multinodular Goiter (TMG) [7,8,13,53-56] whereas other studies presented the same results for GD, but slightly higher carcinoma prevalence within hot nodules and TMG. In many cases thyroid cancer is not known preoperatively, but is found incidentally during postoperative histologic examination of the thyroid. Most carcinomas are small in size and the majority is microcarcinomas [3,26-31]. Some reports describe the thyroid cancer associated with hyperthyroidism as very aggressive, often invasive, and metastatic to regional lymph nodes, even when the primary tumor is small and possibly fatal; in other series the clinical course was not different from euthyroid patient [1,2,6-13,14-20]. The aim of this paper was to report our series of patients operated for Well Differentiated Thyroid Carcinoma (WDTC) associated with hyperthyroidism and evaluate the prognosis of these associations.

Methods

Patients

From January 2000 to June 2022, all consecutive patients who underwent primary thyroid surgery were included in the study. The medical records of these patients were retrospectively reviewed with regard to patient demographics, clinical presentation, preoperative biological and imaging findings, surgical procedures, final pathology and follow-up records. Of these patients, those who presented with hyperthyroidism prior to the thyroidectomy were selected. This study was approved by the Institutional Review Board. Access permit to the included patients’ files was obtained from hospital ethical committees.

Exclusion Criteria

Familial history of thyroid cancer, previous exposure to ionizing radiation or external head-and-neck radiotherapy, previous thyroid or neck surgery.

Variables

After reviewing the included patients’ files, multiple variables were collected. Clinical data: age, gender, symptoms of hyperthyroidism, presence of goiter. Biological data: preoperative serum concentrations of Triiodothyronine (T3), Thyroxine (T4), Thyroid-Stimulating Hormone (TSH), Thyroid-Stimulating Hormone Receptor Antibody (TRAb), Thyroglobulin (Tg), Thyroglobulin Antibody (TgAb) and Thyroperoxidase Antibody (TPOAb) concentrations were assessed at baseline. Radiological and histologic data: Type of imaging done to aid the diagnosis of the thyroid pathology, the etiology of hyperthyroidism was reviewed, results of perioperative pathologic examinations including Fine Needle Aspiration Cytology (FNAC), frozen section, and permanent pathology were also reviewed. Indications for surgery included clinical findings such as severe disease with recurrence after medical treatment, side effects of medication, large goiter size causing locally compressive symptoms, clinical and /or FNAC suspicion of malignancy, or patient preference.

Surgical Management

Iodine-free solutions (chlorehexidine) were used to swab the operative field. All surgeries were done under general anaesthesia using horizontal cervical incision. The thyroidectomies were all performed in a similar fashion with careful dissection attempting to identify and preserve the parathyroid glands with their vascular supply, as well as the recurrent laryngeal nerves. Inadvertently removed or unequivocally devascularized parathyroid glands were removed routinely for immediate auto transplantation into a pocket fashioned in the ipsilateral sternocleidomastoid muscle. The transplantation site was closed with permanent silk suture. Lymph node exploration was systematically performed centrally and bilaterally in cases of papillary thyroid carcinoma. Macroscopically enlarged lymph nodes and adenopathies detected on preoperative imaging studies were all removed for pathologic study. No prophylactic lymph node dissection and no picking procedure were undertaken. We performed Lateral neck dissection (Level II, III, IV, V, and VII) when there were pre or intraoperative evidence of enlarged lymph nodes in these areas. Valsalva maneuver was performed at the end of thyroidectomy in all patients to detect hemorrhage. Cervical wound was closed without drain tubes in all cases.

Perioperative Care

Monitoring of the cervical wound was assessed closely in the postoperative period. The following parameters were queried: volume of the resected thyroid gland, presence of local complications (hemorrhage, hematoma, seroma) and time to hospital discharge. Postoperative complications (vocal cord paralysis and hypocalcaemia) were recorded. The patients were discharged from the hospital when they were asymptomatic or when the serum calcium level rose above 2 mmol/l. The patients were also instructed to contact their physician if symptoms of hypocalcemia developed.

Post-operative variables and Follow-up includes pathologic results of the thyroid specimen, and histological types of thyroid cancer. All data on surgery, postoperative complications and clinical outcomes were analyzed. In this retrospective series, patients were treated after surgery with RAI ablation after thyroid hormone withdrawal or in euthyroidism after administration of recombinant human TSH (rhTSH) when indicated. Post-surgical staging was assessed according to pTNM staging system. During follow-up, ranged from 12 to 240 months, (every 6–12 months), serum FT4, TSH, TRAb (in Graves’ patients), thyroglobulin (Tg) and TgAb were measured. US were repeated every 6–12 months to detect persistent or recurrent regional disease. If US pattern was suspicious for recurrence, FNAB (with Tg measurement in the needle washout fluid) was performed.

Statistical Analysis

The data were plotted on Microsoft excel 2017 and analyzed with descriptive statistics using SPSS version 22. Continuous variables are reported as mean ± standard deviation, and categorical variables are reported as number and percentage. Discrepancy was evaluated by comparing outcomes between the groups using 2x2 Fisher’s exact test; statistical significance for comparison between nominal variables was set at p<0.05.

Results

Preoperative Variables

From January 2000 to June 2022, 6123 patients underwent thyroidectomy by one surgeon (BA). All the medical records of 642 who underwent surgery for hyperthyroidism in our department during this period were analyzed retrospectively. Of these, 73 patients (11%), presented hyperthyroidism with WDTC (54 females and 19 males; mean age at diagnosis, 32.4 years; range, 16–81 years), satisfied inclusion criteria were included in this study. Hyperthyroidism was diagnosed on the basis of elevated T3, elevated T4, and low TSH concentrations in combination with hyperthyroid clinical symptoms and signs. Before administration of antithyroid medications, mean serum T3 concentration was 350.8 ng/dL (range, 173.3–800 ng/dL), and that of T4 was 18.7 ng/dL (range, 14.1–39 ng/dL). Serum TSH concentration was less than 0.1 mIU/mL in each patient. The 73 patients could be classified into three major groups: 46(63%) had GD, 24(33%) had TMG, and 3(4%) had TUG. Methimazole treatment was typically used prior to surgery to achieve a euthyroid state. Three patients had received both antithyroid drugs and radioiodine. The duration of symptoms before hospital visits ranged from 3 months to 11 years. 11 patients presented with large goiter. All the patients 100% had undergone a cervical ultrasound, while 67% (n=49), 7% (n=5), and 5% (n=4) had undergone a thyroid scan, CT scan and MRI of the neck respectively. Thyroid ultrasound revealed calcification in 6 patients with GD.

FNAC under US was performed in 17 patients before thyroidectomy. 4 patients had benign results, seven malignant result, 4 indeterminate results, and the results from 2 patients were inconclusive because of scanty cellularity in the cytology specimen.

Intraoperative Variables

Total or near total thyroidectomy was the surgical procedure performed on 63 and 9 patients respectively. 1 patient with TUG underwent unilateral thyroidectomy. Tumor specimens from 9 patients in whom frozen-section analysis was performed had readings malignant in 6 cases.The number of identified parathyroid glands were 4 in 62 patients (83%), three in 8 patients (11%), and two in 4 patients (6%). Recurrent laryngeal nerves were identified and preserved in all the patients. The mean of the size of the largest nodule was 3.5cm ± 2.09 cm, 61% of the included cases had a size of the largest nodule below 3.5 cm. 17 patients (23%) underwent lymph node dissection. 8 patients (8/73=11%) were positive for lymph node metastases.

Bleeding and or seroma: A total of 4 patients (6%) developed postoperative hematoma and/or seroma. There were no major bleeding, that is, the patient had minor bleeding or seroma not requiring surgical intervention and resolved spontaneously in 3 weeks. None developed a wound infection. Airway compromise did not occurred in this series.

Postoperative length of stay: the postoperative length of stay 1 day in 68 patients (93%), 2 days in 5 patients (7%). Asymptomatic hypocalcemic patients were discharged from the hospital the next day after operation. During follow-up, 15 patients required Calcium and Vitamin D supplementation with no clinical symptoms of hypocalcaemia at 12 months postoperatively. The incidence of permanent hypoparathyroidism was 1%. Unilateral transient vocal cord paralysis was observed in one patient and completely recovered within 4 weeks.

The pathological diagnoses of the resected tumors showed papillary carcinomas n=50; 69%-Follicular Carcinoma (FTC) n=2; 2%-microcarcinoma n=21; 29%. Multifocality and bilaterality were showed in 23% and 18% respectively. Extrathyroidal extension and recurrence were seen in 3% and 1% respectively. Weight of the thyroid tissue averaged 83g (53g- 644g).

Postoperative Management and Follow-up

All patients underwent thyroid-stimulating hormone suppression therapy. Radioactive iodine treatment was considered in patients with high risk for recurrence and when indicated. None of the patients underwent postoperative external radiation therapy. Follow-up evaluations, including physical examination, neck ultrasound, serum thyroglobulin, and thyroglobulin antibodies, were performed at intervals of 6–12 months. There was no peri- or postoperative mortality among our patients. Mean follow-up was 78.3 months (range, 12–240 months). 71 patients were alive and apparently free of residual disease at the time of writing. Two patients had persistence or recurrence of biochemical disease only.

Comparison of WDTC associated with GD, TMG, and TUG

In our series, WDTC was more associated and in statistically significant way with GD then TMG and TUG (63%, 33%, and 4% respectively). The classic variant of PTC being the most common histological type (69%) and showed with GD, TMG, and TUG in 63%, 79%, and 67% respectively (differences statistically significant). Papillary microcarcinoma was associated with GD, TMG, and TUG in 35%, 21%, and 0 % respectively (differences statistically significant). FTC was associated more with TUG (13%), than GD (2%), and TMG (0%). Positive lymph nodes were present with GD, TMG, and TUG in 11%, 13%, and 0% respectively (differences statistically significant). Multifocality and bilaterality were associated with GD, TMG, and TUG in 26%, 20%, and 0% respectively, 20%, 17%, and 0% respectively (differences statistically significant). Extrathyroid extension showed with GD, TMG, and TUG in 2%, 4%, and 0% respectively. Locoregional recurrence and distal metastases were seen with GD, TMG, and TUG in 2%, 0%, and 0%respectively, 0%, 0%, and 0% respectively.

Comparison of WDTC in euthyoid patients and hyperthyroid patients:

In our series, we noted 3 differences (size of the nodules, recurrence, and presence of distant metastases) without reaching statistically significance in the characteristics and prognosis of WDTC in euthyroid patients compared to hyperthyroid patients (Table 2).

Citation: Abboud B; Abboud C. Prognosis of well Differentiated Thyroid Carcinoma Associated with Hyperthyroidism. Annals Thyroid Res. 2024; 10(1): 1092.