Rajeev Parameswaran

Mediastinal parathyroid adenomas and their surgical implications

Primary hyperparathyroidism is a relatively common problem encountered by any endocrine surgical unit. Ectopic parathyroid adenomas have been known to be a common cause of persistent hyperparathyroidism after surgery. A common site of the missed ectopic gland will be that in the mediastinum. However, with the increasing improvement in available imaging, it is likely that this can be diagnosed preoperatively. The surgical approach to the mediastinal parathyroid has also changed vastly over the last decade from maximally invasive to minimally invasive with minimal complications. We provide a review on the entity of mediastinal parathyroid adenomas and their surgical implications.

Rising incidence of thyroid cancer in Singapore not solely due to micropapillary subtype

INTRODUCTION The annual incidence of thyroid cancer is known to vary with geographic area, age and gender. The increasing incidence of thyroid cancer has been attributed to increase in detection of micropapillary subtype, among other factors. The aim of the study was to investigate time trends in the incidence of thyroid cancer in Singapore, an iodine‐sufficient area. MATERIALS AND METHODS Data retrieved from the Singapore National Cancer Registry on all thyroid cancers that were diagnosed from 1974 to 2013 were reviewed. We studied the time trends of thyroid cancer based on gender, race, pathology and treatment modalities where available. RESULTS The age‐standardised incidence rate of thyroid cancer increased to 5.6/100,000 in 2013 from 2.5/100,000 in 1974. Thyroid cancer appeared to be more common in women, with a higher incidence in Chinese and Malays compared with Indians. Papillary carcinoma is the most common subtype. The percentage of papillary microcarcinoma has remained relatively stable at around 38% of all papillary cancers between 2007 and 2013. Although the incidence of thyroid cancer has increased since 1974, the mortality rate has remained stable. CONCLUSION This trend of increase in incidence of thyroid cancer in Singapore compares with other published series; however, the rise seen was not solely due to micropapillary type. Thyroid cancer was also more common in Chinese and Malays compared with Indians for reasons that needs to be studied further.

Surgical Management of Graves' Disease over a 25-year Period in a Single Institution: Comparison of Outcomes between Subtotal Thyroidectomy and Total Thyroidectomy

Introduction: Surgery is offered to patients with Graves’ disease (GD) refractory to medical or radio-iodine therapy. Total thyroidectomy (TT) has been shown to lower recurrence rates of hyperthyroidism but subtotal thyroidectomy (ST) is thought to be associated with lower risk of postoperative complications. The aim of this study was to compare the postoperative outcomes of TT vs ST in the Singaporean population and identify risk factors that might predispose to treatment failure after ST. Materials and methods: This is a retrospective review of consecutive patients who underwent surgery for GD at a single institution in Singapore. Patients who underwent thyroid surgery for GD between January 1991 and December 2015 were included in the study. The primary outcomes studied were rates of recurrent hyperthyroidism, hypocalcemia, recurrent laryngeal nerve injury, and length of stay postsurgery. The secondary outcome was to compare whether preoperative thyroid function and antibody levels predicted for treatment failure post-ST. Results: Over a 25-year period, 79 patients underwent ST and 38 patients underwent TT. The rate of hyperthyroidism relapse post-ST was 20.3% compared with 0% post-TT (p < 0.01). There was no difference between the length of stay, or recurrent laryngeal nerve injury between patients who underwent ST compared with TT. Preoperative antibody levels and biochemical hyperthyroidism did not predict treatment failure after ST. Conclusion: Total thyroidectomy is a more definitive surgical procedure for patients with GD refractory to medical therapy with lower risk of disease relapse and similar temporary and long-term risk of complications when compared with ST.

Evidence-Based Surgery

Millions of major surgical procedures are performed worldwide every year, but despite this, evidence for the indications and benefits of some surgical procedures is lacking. With increasing numbers of surgeries, inappropriate surgical treatments can result in significant cost and hazard to the patient. There has also been an explosion of medical information over the last two decades. The incorporation of such large quantities of knowledge and its application into day-to-day clinical practice is challenging and requires that the best available evidence is required for treatment-related decisions. Rising public and professional expectations are also driving the demand for evidence-based clinical practice. Evidence-based surgery involves the conscientious, explicit, and judicious use of the best clinical and scientific evidence in best clinical care. Evidence-based practice is now an integral part of surgical practice, and its adoption will improve patient and clinical outcomes.

Comparison of prognostic scoring systems in follicular thyroid cancer

INTRODUCTION Many studies have addressed the accuracy of prognostic scoring systems in the treatment of differentiated thyroid cancers as a whole but few have addressed this issue in patients with follicular thyroid cancer (FTC) alone. The aim of this study was to establish the accuracy of the various scoring systems in determining the overall and disease free survival of FTC patients in Singapore. METHODS Retrospective review was undertaken of 82 patients with FTC treated at a single tertiary institution between January 2000 and December 2014. Demographic, clinical, pathological and treatment outcomes were analysed. Prognostic scoring systems evaluated for the cohort included TNM (Tumour, Nodes, Metastases), AGES (Age, Grade, Extent, Size), MACIS (Metastases, Age, Completeness of resection, Invasion, Size), AMES (Age, Metastases, Extent, Sex) and EORTC (European Organisation for Research and Treatment of Cancer). Statistical analysis was performed by plotting Kaplan‐Meier survival curves and using the Cox proportional hazards model. RESULTS There were 29 male and 53 female patients with a mean age of 48 years. The mean follow‐up duration was 88 months and there were 7 deaths (9%). The ten‐year overall survival rate was 90%. Factors predictive of survival on univariate analysis were age, size of tumour, invasiveness, completeness of resection, metastasis, external beam radiotherapy, and risk scores using the AGES and MACIS scoring systems (p<0.05). On multivariate analysis, AGES and MACIS provided the best prognostic information. CONCLUSIONS MACIS is the best prognostic scoring system currently available for FTC and it is superior to other scoring systems in term of guiding management. The scoring systems require further development to accommodate variations in clinical practice globally and to improve the prognostic accuracy.