Endocrine Abstracts

The incidence of recurrent well-differentiated thyroid cancer (WDTC) continues to rise as better imaging test and more sensitive monitoring improves disease surveillance. Despite its excellent prognosis, increasing morbidity from recurrent diseases continues to affect long-term outcome of most patients leading to higher medical cost and poorer quality of life. Filipino ethnicity in particular was reported to have the highest incidence of thyroid cancer with a highly aggressive and recurrent nature. This paper aims to identify associated risk factors for recurrence among Filipinos with WDTC. This is a retrospective cohort study of 723 patients diagnosed with WDTC seen at Philippine General Hospital (PGH). Study population was divided into groups based on presence or absence of recurrence. Recurrence was considered if the patient had clinical, biochemical or radiologic evidence of cancer remnants after surgery. Multivariable logistic regression analyses were used to determine significant predictors of recurrence. 214 (32.9%) patients with papillary thyroid cancer (PTC) and 23 (29.1%) patients with follicular thyroid cancer (FTC) developed recurrence within a median interval of 13 months and 26 months from thyroidectomy respectively. Age >45 (HR=1.44), multifocality of cancer (HR=1.43), nodal involvement (HR=4.0) and distant metastases at presentation (HR=2.78) were the risk factors identified to negatively impact the risk of recurrence for PTC. Follicular variant histology (HR=0.60)) and post-surgical radioactive iodine ablation therapy (HR=0.31) were protective factors for PTC recurrence. Distant metastases at presentation (HR=19.4) and post-surgical radioactive iodine ablation therapy (HR0.41) were identified for FTC recurrence. Lymph node metastases at presentation was the most important predictor of recurrence in PTC while it was distant metastases at presentation for FTC recurrence. Identified recurrence factors for WDTC among Filipinos in this study will be helpful in guiding the intensity of their treatment strategies and long-term thyroid cancer surveillance aimed to reduce future morbidity and mortality.