When your doctor asks you if you want your child to have the human papillomavirus vaccine – HPV — don’t dismiss it as a casual question. What you could be deciding is whether you want to protect your child against eventual cancers.

About 80 percent of the adult population has been exposed to the HPV (human papillomavirus), said Dr. Chesney Thompson, chief of general obstetrics and gynecology and a professor at the University of Colorado School of Medicine who sees patients at UCHealth’s University of Colorado Hospital and Boulder Health Center.

The vaccine can protect a young woman from getting a condition called cervical dysplasia, “abnormal cells that, if left untreated, can turn into cancer, but are not (yet) cancer,” Thompson said.  There is a broad spectrum of abnormalities that range from nearly normal cells to full-blown cancer cells. Cervical dysplasia is “sort of a stepping stone progress where the abnormalities become more serious over time and can turn into cancer” if not treated. The time frame for that process, however, “is years, not days, weeks or months,” he said.

The cervix is the lower part of the uterus that leads into the vagina. It is the cervix that dilates during childbirth to allow the fetus to pass through.

Not everyone who gets HPV develops cervical dysplasia and cancer, however.

“It’s not inevitable,” Thompson said. “Some people get mild changes and sometimes they regress on their own. But once it gets more advanced, then it’s more likely to keep progressing.”

Anyone who is sexually active may get HPV. The insidious thing about HPV is that there are no real symptoms early on. Some patients may develop genital warts. A few women may have some post-coital bleeding, but not always. The only way to catch it is with regular Pap smears, he said. If abnormal cells show up there, it’s cause for further investigation.

“Depending on degree of abnormality, it might require a further examination, such as a colposcopy,” which gives the physician a closer view of the cervix to identify areas that appear abnormal. If concerning areas are identified, a biopsy may be taken, he said.

“That’s more definitive than a Pap smear, and you get a real picture of the degree …of abnormality.” Depending on the severity of the results, the condition may require treatment, though typically patients with mild changes are not treated. “We just keep an eye on it and elect to treat it later if necessary. It’s easier to treat cervical dysplasia than cancer, obviously.”

HPV is spread by direct sexual contact, which is why most doctors recommend a child get the vaccine before age 12, so it is working before they ever have a sexual encounter. And it’s recommended for both boys and girls. Boys can get HPV, too, and it can lead to other male-specific cancers.

Girls and women who are most at risk of cervical dysplasia include those who have an illness that suppresses the immune system.

“Because it is an infection, patients who have a healthy immune response can sometimes clear the virus,” Thompson said. “But patients with compromised immune systems, like those with HIV, or who have had transplants, are undergoing chemotherapy, have a chronic illness or use steroids regularly” may not be able to fight the virus. It also turns out that smoking interferes with the body’s ability to suppress HPV. And having multiple sexual partners increases your risk of getting infected, studies show.

There are various treatments for cervical dysplasia, but Thompson said “the best solution is to get the vaccine at an early age.”

There are literally more than a hundred strains of HPV, he added, but about nine are major culprits against which the vaccine can guard. (There are two vaccines available and a physician can explain the differences to their patients.)

As usual, some parents protest vaccines in general, and Thompson says the HPV vaccine has not yet gained the general acceptance that some others have. But he strongly recommends educating parents about its importance.

As physicians, “I think we should be more emphatic,” he said. “After all, this is a cancer prevention treatment.”

For more information, Thompson suggests that parents or young adults who are interested or concerned about the vaccine talk to their doctor or go online to ASCCP.org.