Reproductive cell: Egg and sperm cells. Each mature reproductive cell carries a single set of 23 chromosomes.

Pelvic: Having to do with the pelvis, the lower part of the abdomen, located between the hip bones.

Mutation: Any change in the DNA of a cell. Mutations may be caused by mistakes during cell division, or they may be caused by exposure to DNA-damaging agents in the environment. Mutations can be harmful, beneficial, or have no effect. If they occur in cells that make eggs or sperm, they can be inherited; if mutations occur in other types of cells, they are not inherited. Certain mutations may lead to cancer or other diseases.

Vaccine: A substance or group of substances meant to cause the immune system to respond to a tumor or to microorganisms, such as bacteria or viruses.

Disease progression: Cancer that continues to grow or spread.