Juan Rivera

Emerging trends in the diagnosis and treatment of acromegaly in Canada

To evaluate demographic data and quality of care of patients with acromegaly in Canada and their evolution over time and secondly, to evaluate predictors of co‐morbidities and treatment outcomes.

Low Vitamin D and Risk of Post-thyroidectomy Hypocalcemia:

Objective: 1) Determine if low vitamin D reduces risk of post-thyroidectomy hypocalcemia. 2) Verify if this is an independent effect. Method: Retrospective study of 139 total thyroidectomy patients (October 2009-October 2011) at a McGill University teaching hospital. Preoperative 25-hydroxy-vitamin D (25OHD), calcium, and PTH were measured. Patients were assessed for postoperative hypocalcemia. Low vitamin D (LVD) was defined as 25OHD ≤70 nmol/L (28 ng/mL) and optimal vitamin D (OVD) was defined as 25OHD >70 nmol/L (28 ng/mL). Results: Hypocalcemia occurred in 3.2% (2 of 62) patients with LVD and 10.4% (8 of 77) patients with OVD (OR 0.2875, P = .124). No patients with vitamin D deficiency (VDD), defined as 25OHD ≤35 nmol/L (14 ng/mL), developed hypocalcemia. Univariate analysis did not show age, sex, malignancy, presence of thyroiditis, number of preserved parathyroids, parathyroid autotransplantation, preoperative PTH, or preoperative calcium to be significantly predictive. Multivariate analysis confirmed no confounding factors in vitamin D analysis, but also did not show any independent risk factors. Fisher analysis comparing total versus completion thyroidectomy was marginally significant (P = .064) for predicting hypocalcemia. Conclusion: Transient hypocalcemia appears to occur less frequently in patients with VDD, however in our limited study we were unable to elucidate whether this was significant. Future study observing a larger population and excluding completion thyroidectomy patients may help to clarify whether VDD impacts risk for hypocalcemia.

Effects of Chronic Lymphocytic Thyroiditis on the Clinicopathological Features of Papillary Thyroid Cancer

Background: The effects of chronic lymphocytic thyroiditis (CLT) on the presentation and outcome of papillary thyroid carcinoma (PTC) have long been a topic of controversy. Objective: To evaluate the effect of coexistent CLT on the clinicopathological features of PTC. Design: Retrospective study. Patients: All patients with PTC who had been followed by the 2 co-investigators (Juan Rivera and Richard J. Payne) between 2006 and 2011 were included. Results: CLT was present in 35% (166) of the included patients and was associated with a higher proportion of patients with TNM stage I (p = 0.027) and fewer patients with persistent disease (p = 0.014) in comparison with the PTC-only group. Analysis of the data based on age (<45 or >45 years) revealed that in the older group, the presence of CLT was associated with fewer patients with persistent disease (p = 0.03) and capsular invasion (p = 0.05). However, in patients <45 years of age, the presence of CLT was associated with more capsular invasion (p = 0.003) and extrathyroidal extension (p = 0.004) compared with the PTC-only group. Conclusions: CLT in patients with PTC was associated with lower-stage disease and less disease persistence in patients >45 years of age. In patients <45 years, the presence of CLT appeared to be associated with unfavorable pathological features.