Advancing age is associated with a reduced risk for papillary thyroid carcinoma (PTC) enlargement among adults undergoing active surveillance, according to results from a systematic review and meta-analysis published in JAMA Otolaryngology-Head & Neck Surgery.
Active surveillance is commonly recommended for low-risk PTC. As there are conflicting reports on the association between age at diagnosis and risk for PTC progression in patients undergoing active surveillance, the goal of the current systematic review and meta-analysis was to investigate this association.
The researchers completed a search for randomized or observational studies, systematic reviews, cohort studies, or cross-sectional studies that included adults undergoing active surveillance for primary management of low-risk PTC, and reported change in primary tumor size or incident nodal metastases relative to patient age at diagnosis or onset of active surveillance.
The review included 5 studies from Japan, Korea, and the United States, with 3 studies including only patients with primary microcarcinoma and 2 studies including some patients with PTC with tumor diameter between 1 and 2 cm. The mean or median age of participants ranged from 51.0 to 55.2 years for the 4 studies that had this estimate reported, and 75% to 90% of participants were women.
Of 4 studies comparing the risk for an increase in tumor size of ≥3 mm in maximal diameter in younger vs older patients, 2 reported a significantly increased risk in younger individuals. In a random-effects meta-analysis including data from these 2 studies (1619 patients), the adjusted relative risk for tumor growth in individuals aged 40 to 50 years compared with younger patients was 0.507 (95% CI, 0.288-0.891).
In a similar fashion, 2 studies reported a significantly higher risk for tumor volume increase among younger compared with older individuals. For 1232 patients aged 40 to 45 years, the unadjusted relative risk for tumor volume increase (>50% or ≥50%) compared with younger individuals was 0.649 (95% CI, 0.505-0.833).
Incident nodal metastases were relatively rare events among younger and older patients. The pooled relative risk for incident clinical nodal metastases among 1806 patients aged ≥40 years was 0.22 (95% CI, 0.10-0.47) in 3 studies. However, in a secondary analysis, the risk difference was not significant.
There was no statistically significant heterogeneity in any of the meta-analyses.
The study had several limitations, including the limited number of studies and patients available for inclusion, short follow-up periods, and an inability to assess for publication bias or subgroup effects.
“This study suggests that older age may be associated with a reduced risk of primary papillary thyroid carcinoma tumor growth under active surveillance,” concluded the researchers.
Koshkina A, Fazelzad R, Sugitani I, et al. Association of patient age with progression of low-risk papillary thyroid carcinoma under active surveillance: a systematic review and meta-analysis [published online April 16, 2020]. JAMA Otolaryngol Head Neck Surg. doi:10.1001/jamaoto.2020.0368