Ciappuccini R, Saguet-Rysanek V, Giffard F, et al. - Prostate-specific membrane antigen (PSMA) expression was seen in two-thirds of neck persistent/recurrent disease patients, was linked to poor prognostic variables, and was associated with shorter progression-free survival (PFS). This preliminary study may open up new avenues for the treatment of radioiodine (RAI)-refractory DTC.

• Data were analyzed from 44 consecutive differentiated thyroid cancer patients who underwent neck reoperation in a comprehensive cancer center between 2006 and 2018.

• Thirty patients [immunoreactive score (IRS) ≥ 2] had at least one PSMA-positive lesion, with proportions similar in RAI-positive and RAI-negative patients.

• However, the proportion of PSMA-positive disease and the mean IRS were higher in 18FDG-positive patients than in 18FDG-negative patients in RAI-negative patients.

• Moreover, mean IRS was higher in patients ≥ 55 years, in patients with large primary tumors (> 40 mm), or in aggressive subtypes, and it was correlated with the structural disease at last follow-up.

• Shorter PFS was associated with high PSMA expression (IRS ≥ 9).