The increase in thyroid cancer incidence has been attributed in large part due to small papillary thyroid cancers measuring less than 2 cm in size. Because other studies have shown a low risk for growth of these small cancers over time, the American Thyroid Association has supported observation as opposed to surgery as an option in these low risk papillary thyroid cancers. This is known as active surveillance. Little is known about how these small cancers grow and change over time, though only 10-15% of these patients have demonstrated cancer growth in the previous studies. This study was done to demonstrate the rate and magnitude of growth of small papillary thyroid cancers over time in a group of patients in the US. The goal of the study was to evaluate growth of small papillary thyroid cancers over time to better determine treatment, monitoring and timing of surgery if necessary of these patients.
THE FULL ARTICLE TITLE:
Tuttle RM et al. Natural history and tumor volume kinetics of papillary thyroid cancers during active surveillance. JAMA Otolaryngol Head Neck Surg. August 31, 2017 [Epub ahead of print].
SUMMARY OF THE STUDY
A total of 291 patients at Memorial Sloan Kettering Cancer Center in New York who were being followed by active surveillance for papillary thyroid carcinoma measuring 1.5 cm or smaller were included. Of these, 75.3% of the patients were women, average age was 51 year old and 79.7% had cancers under 1cm in size. Patients had normal TSH values, no evidence on ultrasound for extension of the lesion beyond the thyroid or region metastases (specifically lymph node metastases) and no evidence for spread of the cancer beyond the neck. Patients were monitored by ultrasound every 6 months for two years, then annually. If the cancer increased by 3 mm or more in greatest dimension from the pre-biopsy ultrasound measurements or if there was suggestion of spread of the cancer outside of the thyroid capsule, or if the spread of the cancer to lymph nodes was found, surgery was suggested. Measurements of the cancer volume was performed prior to the fine needle aspiration and at each time point, using ultrasound measurements of height, width, and length of the nodule. Percentage change in volume was considered significant if greater than 50% increase from baseline.