- Investigators have reported 2 cases of mother-to-infant cancer transmission in Japan.
- The case reports describe lung cancer in 2 boys, possibly resulting from transmission during vaginal delivery by mothers with cervical cancer.
Why this matters
- Mother-to-infant cancer transmission is extremely rare, with an estimated incidence of ~1 infant per every 500,000 mothers with cancer.
- Previously reported cases have been presumed to have occurred via transplacental transmission.
- The 2 cases were incidentally discovered during an analysis of the results of routine next-generation sequencing testing in the prospective gene-profiling TOP-GEAR trial.
- Funding: Japan Agency for Medical Research and Development; Ono Pharmaceutical; others.
- Genetic analyses and other evidence indicated that lung cancers in both boys developed after aspiration of uterine cervical cancer tumor cells into lungs during passage through the birth canal.
- Tumors in both boys lacked the Y chromosome and shared multiple somatic mutations, an HPV genome, and single-nucleotide polymorphisms alleles with tumors from the mothers.
- Tragically, both mothers who were diagnosed with cervical cancer after the births died while their offspring were still infants.
- In the first case, a 23-month-old toddler was diagnosed with neuroendocrine carcinoma of the lung.
- Following 2 unsuccessful chemotherapy regimens, the toddler was enrolled in a clinical trial of nivolumab.
- The response continued for 7 months, with no appearance of new lesions.
- Lobectomy was performed to resect a single remaining nodule, and there was no evidence of disease recurrence at 12 months post lobectomy.
- In the second reported case, a 6-year-old boy was diagnosed with mucinous adenocarcinoma in the left lung.
- The tumor grew very slowly, which is rare for cervical adenocarcinoma.
- Mucinous adenocarcinoma is an unusual morphologic finding for a primary lung tumor, but it was similar to the uterine cervical tumor in the mother.
- The boy received chemotherapy and experienced a partial response, but there was a recurrence in the left lung 3 months later.
- Following additional chemotherapy, he underwent total left pneumonectomy and was subsequently disease-free.