Possible Link Found Between Age and Papillary Thyroid Cancer Progression in Adults Being Surveilled

Study findings suggest there may be an association between advancing age and reduced risk for papillary thyroid tumor enlargement in patients being actively monitored (JAMA Otolaryngol Head Neck Surg. 2020 Apr 16. Epub ahead of print).

“Active surveillance is sometimes considered as a disease management option for individuals with small, low-risk papillary thyroid carcinoma,” wrote Alexandra Koshkina, MD, MSc, University of Toronto Endocrinology Fellowship, Ontario, Canada, and colleagues, who sought to evaluate whether age is tied to progression of low-risk papillary thyroid carcinoma in adults being actively surveilled.

Data were gathered from 8 electronic databases before being independently screened by 2 of the investigators. Dr Koshkina et al also sought additional from authors and performed random-effects meta-analyses using incidence data. Overall, 1658 citations were screened, and 62 full-text articles were reviewed, including 5 studies (3 involved exclusively microcarcinomas and 2 involved tumors up to 2 cm in maximal diameter).

Based on 4 of the studies, study participants had a mean age 51.0 to 55.2 years. Follow-up lasted for a mean or median of ≥5 years in 3 studies and approximately 2 years in 2 studies.

When adjusted for confounders, the pooled risk ratio for tumor growth of ≥3 mm in maximal diameter in patients aged 40 to 50 years was 0.51 compared with younger individuals (95% CI, 0.29-0.89; n = 1619, 2 studies), and the unadjusted risk ratio of this outcome for those aged ≥40 years was 0.55 (95% CI, 0.36-0.82; n = 2097, 4 studies).

The unadjusted risk ratio for volume increase in any tumor between adults aged 40 to 45 years and younger individuals was 0.65 (95% CI, 0.51-0.83; n = 1232, 4 studies).

Among individuals aged ≥40 years, the pooled risk ratio for incident nodal metastases was 0.22 (95% CI, 0.10-0.47; n = 1806, 3 studies), but in a secondary analysis, the difference in risk was not found to be significantly unalike.

According to the investigators, no statistically significant heterogeneity was observed in any of the meta-analyses, and no thyroid cancer-related deaths or incident distant metastases occurred.

“This study suggests that older age may be associated with a reduced risk of primary papillary thyroid carcinoma tumor growth under active surveillance. Incident metastatic disease is uncommon during active surveillance,” Dr Koshkina and colleagues concluded.—Hina M. Porcelli