Japanese researchers have identified what is believed to be the first reported cases of women vaginally transmitting cervical cancer to their infants via birth, according to a case study published in The New England Journal of Medicine.
The case study focuses on two infant boys who developed pediatric lung cancer at age 5 and 23 months, respectively. Both of their mothers had undetected cervical cancer at the time of their deliveries. The researchers said the children's cancer probably resulted from mother-to-infant transition of uterine cervical tumor cells during their birth.
"Spontaneous regression of some lesions in the first child and slow growth of the tumor mass in the second child suggested the existence of alloimmune responses against the transmitted tumors," the researchers wrote. An alloimmune response is defined as an immune response to antigens from another human.
The cancer drug nivolumab, known by the brand name Opdivo, proved effective at shrinking one child's tumor. The second child, who is now cancer-free, underwent chemotherapy and had his left lung removed.
While vaginal transmission of cancer to infants is very rare, the study has "tremendous implications for the way we think about delivery" and challenges the assumption that blood is the primary vector for maternal-fetal transmission, Melissa Frey, MD, an OB-GYN and oncology specialist at Weill Cornell Medicine in New York City who was not involved in the study, told Medpage Today.