NONOPERATIVE MANAGEMENT OF DIFFERENTIATED THYROID CANCER IN CALIFORNIA: A POPULATION-LEVEL ANALYSIS OF 29,978 PATIENTS

There has been increasing interest in active surveillance of papillary thyroid microcarcinoma. The objective of this study was to characterize the incidence and outcomes of nonoperatively managed differentiated thyroid cancers (DTCs) in California. Biopsy-proven DTCs from the California Cancer Registry were linked to data from the California Office of Statewide Health Planning and Development (2004-2012). Low-risk tumors were defined as localized disease measuring 3 to 4 cm (9.9%). There were no disease-specific deaths in the low-risk, nonoperative group (median follow-up [interquar-tile range], 21.3 [5.7 to 51.1] months). The proportion of patients managed nonoperatively remained relatively stable over the study period (mean increase 0.1% per year, P = .09). All P values were