A Japanese team said Thursday it had confirmed cases of pediatric lung cancer resulting from a mother-to-baby transmission of cervical cancer during birth for the first time in the world.
Two boys were found to have developed lung cancer after swallowing amniotic fluid containing cervical cancer cells in their first cries. The cells mixed into the fluid during birth.
An article on the findings was published in the digital edition of the New England Journal of Medicine. The research team included members of the National Cancer Center.
The team's analysis found that the DNA arrangements of cancer cells from the boys and their mothers included the same mutations. Also, the cancer cells in the boys did not contain the Y chromosome, usually found in men.
One of the boys was treated with the cancer immunotherapy drug Opdivo, known generically as nivolumab, while the other had his lung cancer surgically removed. Both mothers, however, died after being diagnosed with cervical cancer at or after the time of birth.
Given that only one in a million children develops lung cancer, the two boys "are very rare cases," said research team member Chitose Ogawa, head of the Pediatric Oncology Department of National Cancer Center Hospital.
"It's important to prevent mothers from developing cervical cancer," Ogawa said.
The main cause of cervical cancer is infection with certain strains of the human papillomavirus, or HPV. Most women infected with the sexually transmitted virus do not develop the cancer.
Vaccination against HPV before turning 17 years old prevents women from developing cervical cancer, and regular checkups make it easier to find the cancer at an early stage.
Ayumu Arakawa, another team member from the same hospital department, believes that cancer cell transmission via amniotic fluid can be prevented through cesarean sections.
Among other types of cancer, skin cancer is known to be transmissible from mothers to babies via blood passing through the placenta.