Thyroid Cancer Active Surveillance Program Retention and Adherence in Japan

Small papillary thyroid cancers are the most common type of thyroid cancer, with the incidence increasing across the world. Active surveillance of appropriate cancers has the potential to reduce harm from overtreatment but is a significant de-escalation from prior practice. Mechanisms that inform the rates of retention and adherence have not been described and need to be understood if broader uptake is to be considered.

To evaluate patient retention, adherence, and experience in the largest and most long-standing thyroid cancer active surveillance program, to our knowledge.

A cohort study using convergent design mixed-methods analysis of attendance data, semistructured interviews, and field observation was conducted at Kuma Hospital, Kobe, Japan. Participants included 1179 patients who were enrolled in surveillance between February 1, 2005, and August 31, 2013, and followed up through December 31, 2017. Data analysis was performed from January 25, 2018, through September 30, 2020.

Patients were considered adherent if they underwent ultrasonography within at least 13 months of the previous ultrasonographic examination. Patients were considered retained if they continued surveillance with an ultrasonographic examination at least every 2 years, without having had surgery for patient preference or clinical reasons.

Of the 1179 patients included in the study, 1037 (88%) were women. The mean (SD) age was 56 (13.5) years (median, 57 years). Patients were followed up for up to 12.76 years (median, 5.97 years) and underwent a median of 9 ultrasonographic examinations (range, 2-50); 76 patients (6.4%) had surgery for clinical reasons. In analysis of retention, 53 of 1179 patients (4.5%) changed to surgery after a mean (SD) of 2.14 (1.53) years (median, 1.47; range, 0.14-7.17 years); at the study end point, 101 of 1179 patients (8.6%) had not been seen at Kuma Hospital in at least the past 2 years. Kaplan-Meier analysis to 10 years of follow-up time without structural progression estimated that 21.5% (95% CI, 17.0%-28.2%) of patients would not have had an ultrasonographic examination within at least the past 2 years. Mean adherence over a surveillance period of 10 follow-up ultrasonographic examinations (8878 person-examinations) was 91% (range, 85%-95%). Receipt of detailed test results, education regarding active surveillance, and supportive/collaborative style interactions with their physician were identified by patients as key factors for continuing surveillance.

For patients with low-risk papillary thyroid cancer participating in active surveillance, retention in the program and adherence to follow-up ultrasonographic examination do not appear to be barriers to broader implementation of surveillance. The program's success may benefit from an approach analogous to traveler (patient) and their guide (clinician): the clinician advising on options, advocating for the optimal path over time, and supportively reaffirming the care plan or recommending alternatives as conditions change.