DICER1 mutational analysis of pleuropulmonary blastoma: a single institutional experience.

BACKGROUND

DICER1 syndrome is a relatively recently identified hereditary tumor predisposition syndrome, strongly associated with pleuropulmonary blastoma (PPB) and other neoplasms, but its actual status in Japan is unclear.

METHODS

We retrospectively performed germline DICER1 gene analysis in patients with suspected PPB at our institute between 2003 and 2022. Relevant clinical data were extracted from the medical records.

RESULTS

Six patients with PPB were identified, of whom four harbored pathogenic germline variants in DICER1. Only one patient had a family history of childhood or juvenile cancer. Genetic testing of unaffected family members was performed in two families, revealing three asymptomatic carriers, including one infant carrier. Two of the three carriers underwent active surveillance, and no new tumors were detected on follow-up at 6 and 2.5 years after diagnosis, respectively.

CONCLUSIONS

A high prevalence of DICER1 germline variants was observed in patients with PPB, consistent with previous studies. Family history alone may be insufficient to suspect DICER1 syndrome, and thus, proactive genetic testing of family members is advisable in all cases of PPB.