A woman in Phoenix, AZ, died earlier this month as a result of stage-four melanoma. Briana Cox discovered she had the disease when she collapsed just two months after the birth of her daughter, Addison. By the time the cancer was caught, it had spread to her brain, liver, and other parts of her body.
Shortly after Briana’s diagnosis, four dark spots appeared on baby Addison’s forehead, ultimately leading to the very same diagnosis as her mother; stage-four melanoma. The cancer has also spread to her brain and liver, too.
While she was pregnant, Briana’s cancer had metastasized and was transmitted through the placenta to her baby. The placenta typically protects the fetus from transmission and cases like this are extremely rare; only a few dozen have occurred in the past 140 years.
Research on mother-to-fetus transmission is limited, but doctors have uncovered the cause. Normally a fetus’ immune system would destroy any of the mother’s cancer cells; however, in these cases, the cells are missing a significant piece of the sixth human chromosome. This missing region of the chromosome is normally what creates markers for the immune system to latch onto. As a result, the cancer survived because it was invisible to the fetus’ immune system.
Carmen Calvo, PES