DIFFERENTIATED THYROID CARCINOMA (DTC) PATIENTS REFFERED FOR RADIOACTIVE IODINE THERAPY AT FIRST PRESENTATION : A 10-YEAR REVIEW

Abstract

OBJECTIVE: To evaluate the patient characteristics, histological subtype, presenting symptoms and metastatic evidence in thyroid cancer patients referred for radioactive 1odine (RAT) therapy at first presentation.

METHODS: A retrospective study of patients with differentiated thyroid carcinoma (DTC) registered at Nuclear Medicine Section, Siriraj Hospital during January 1989 to December 1998 was reviewed.

RESULTS: Five hundreds and sixty-six DTC patients, aged 9-96 years (mean=46.8±16.7), including 440 women and 126 men were analyzed. The overall female/male ratio was 3.5:1. According to the histopathology, 370 papillary carcinomas (65.4%), 191 follicular carcinomas (33.7%), 5 Hiirthle cell carcinomas (0.9%) were found. The most common age group was in the range of 31-60 years, accounting for 56% of all patients. There was at least one organ metastasis at first presentation in 235 cases (41.5%). Lymph node is the most often involved organ found in 169 cases (29.9%), followed by lung (52 cases, 9.2%) and bone (49 cases, 8.7%). Ninety-one patients (16.1%) revealed distant metastases at the time of referral. Papillary thyroid carcinomas most commonly metastasize to regional lymph node (39.7%) followed by lung (8.4%), and bone (4.3%), while follicular carcinoma more often metastasize to bone (17.3%) and lung (10.5%).

CONCLUSION: DTC is not uncommon in Thais and affects women rather than men. Papillary carcinoma is the most common histological subtype followed by follicular carcinoma. Since the prevalence of regional node and distant metastases is quite high at presentation, early diagnosis and appropriate treatment are essential for improving the disease outcomes.