A descriptive study of papillary thyroid carcinoma in a teaching hospital in Chennai, India

In the 1994 Chennai population-based cancer registry, thyroid carcinoma constituted 1% and 2% of all incident cancers among males and females, respectively. The aim of our study was to conduct an epidemiological survey of the pattern of papillary thyroid carcinoma in the Chennai Government General Hospital and the Chennai Cancer Institute.

Our data base included a total of 264 (58 males and 206 females) consecutive cases of papillary thyroid carcinoma admitted to the Government General Hospital and 164 (42 males and 122 females) cases from the Chennai Cancer Institute.

There was a female preponderance (100 males and 328 females) (p < 0.001). The median age at diagnosis was 39 years among males and 32 years among females. The distribution of cases by residential area lay scattered from < 1 km to > 100 km, with the majority (28%) from the city of Chennai and its suburbs in the Government General Hospital, while 52% of the cases in the cancer institute were from the neighbouring state. Iodine intake was present in 75% of cases (p < 0.001). The diagnosis of thyroid cancer was confirmed by fine needle aspiration cytology in most (88%) of the cases. The extent of disease in the Government General Hospital and the Cancer Institute were as follows: localized in 66% vs 32%; spread to surrounding structure with or without nodal involvement in 26% and 59% presence of only secondary nodal involvement in 3% and 1%, distant metastasis in 5% and 8%, respectively. The primary modality of treatment was surgery with total thyroidectomy being performed in 82%, while the rest underwent a hemithyroidectomy.

The cumulative life-time risk of thyroid cancer in Chennai was one in 970 in males and one in 565 in females. High dietary intake of iodine was the most significant risk factor for the etiology of papillary thyroid carcinoma in our study.