Of all the gynecologic cancers that affect women, cervical cancer is the most preventable.

"That's the most important thing I want women to know," says Dr. Anne Alaniz, a gynecologic oncologist at Houston Methodist.

How to prevent cervical cancer? It's going to take some understanding and action on your part.

From what causes cervical cancer to the steps you should take to reduce your risk, Dr. Alaniz shares eight facts women need to know.

1. HPV is the most common cause of cervical cancer

Human papillomavirus, or HPV, is a common virus that's passed from person-to-person during sex. It's also the leading cause of cervical cancer.

"HPV is estimated to be responsible for more than 90% of cervical cancers," says Dr. Alaniz. "Having a current or past infection doesn't mean a woman will get cervical cancer, though. There are many different types of HPV, and not all are the same in terms of virulence and ability to cause cancer."

Hence, the importance of following cervical cancer screening recommendations, which include periodic HPV testing. Not only can screening identify infection, it can also determine whether you're infected with a high-risk HPV. These are the types capable of causing persistent infection of the cervix and potentially leading to cellular changes that ultimately develop into cancer.

"HPV testing is how we identify which women are at the highest risk of getting cervical cancer," says Dr. Alaniz. "We have an algorithm to determine how frequently a woman needs to be screened that's based entirely off the results of her HPV testing."

2. Almost 9 in 10 people will get HPV at some point in their lives

"Having HPV has nothing to do with how promiscuous you are," says Dr. Alaniz. "It's so prevalent in the general population that even someone who's had just one or two sexual partners in their lifetime can be infected with HPV."

Indeed, it's the most common sexually transmitted infection (STI).

All told, 85% of people will get HPV at some point, according to the CDC, and more than 42 million Americans are infected with the virus at any given time. Nor is it just a concern for adults. Teens are included in the almost 13 million Americans who develop a new HPV infection every year.

The virus typically causes no symptoms, and most people won't even know they're infected — though it's important to note that asymptomatic carriers can still pass the virus to someone else.

Most HPV infections resolve on their own within a few years, but some types persist and become chronic. It is these viruses that over time can lead to cancer, a reminder why HPV testing is a critical part of cervical cancer screening.

3. Teens and young adults should be vaccinated against HPV

Despite HPV's prevalence and potential consequence, it's not all bad news. There's a vaccine that can protect both women and men against the types of HPVs most likely to cause cancer.

The vaccine is most effective before a person is ever exposed to HPV, which is why it's recommended that girls and boys be vaccinated between the ages of 11 and 12. But older teens and younger adults who aren't yet vaccinated benefit from it as well.

"The most recent guidelines have actually increased the upper limit to receive the vaccine to age 45," Dr. Alaniz adds.

If you're between the ages of 27 through 45, talk to your doctor about whether HPV vaccination may be beneficial for you.

4. Women should begin cervical cancer screening around age 21

Cervical cancer screening is part of a woman's annual well-woman exam with her gynecologist. In addition to HPV testing, such screening includes a Pap smear, a test that checks for suspicious changes to cells of the cervix.

"A Pap test can identify precancerous cells that are abnormal but haven't yet developed into cancer," explains Dr. Alaniz. "These precancers can be treated easily and effectively."

How often a Pap smear and HPV testing are needed depends on the recommended screening guidelines for your age and level of cervical cancer risk. Some women may need only one or both of these tests every few years, whereas a woman infected with a high-risk HPV likely will need to be screened more frequently.

Your gynecologist can help you understand what's right for you.

5. It's a known fact that screening prevents cervical cancer deaths

"If you look across the board at women who get their Pap smears and HPV testing following the recommended guidelines, it's incredibly rare to find one who died from cervical cancer," says Dr. Alaniz.

That's because, with regular screening, an issue is either caught when it's a precancer or the cancer is found so early that it can be treated and cured.

"Cervical cancer outcomes are so much more favorable with early disease," says Dr. Alaniz.

The benefits of early detection also extend to which cervical cancer treatment options are available. For instance, if the cancer is small and limited to the cervix, fertility-sparing procedures are an option for women still in their childbearing years.

6. HPV testing reduces unnecessary diagnostic procedures

"Cellular changes on the cervix can be cancer, but they can also be inflammation related to a yeast infection or post-menopausal vaginal irritation," explains Dr. Alaniz.

This means that not every abnormal Pap test needs to be followed up with a colposcopy or other diagnostic test.

Before HPV testing, a colposcopy was the best next step for a doctor to safely rule out cervical cancer or precancer. This often resulted in women undergoing extra tests and procedures.

HPV testing has changed all of that.

"Now, we simply follow up an atypical Pap smear with high-risk HPV testing," says Dr. Alaniz. "If that's positive, we know the abnormal cells are more likely to be precancerous and that we need to do further testing."

7. Never ignore cervical cancer symptoms

Even if you're following screening guidelines, it's important to know the signs of cervical cancer.

Cervical cancer symptoms include:

• Vaginal bleeding between menstrual cycles or after menopause
• Pelvic pain during sexual intercourse
• Vaginal bleeding after sexual intercourse

"When cervical cancer is more advanced, symptoms can also include leg swelling, bowel and bladder issues and back pain," adds Dr. Alaniz.

Don't wait until your next well-woman exam to talk to your doctor if you notice these symptoms. The earlier cervical cancer is caught, the better.

8. Advanced cervical cancer is very difficult to treat

Unlike some other types of cancer, cervical cancer isn't a very chemosensitive disease. It's best treated surgically, Dr. Alaniz notes. But the larger the cancer or the more it's spread, the less effective surgery becomes.

"This really is a disease we need to find early to be able to treat it successfully," says Dr. Alaniz. "Survivorship becomes very, very low with advanced disease."

It's the final thing Dr. Alaniz wants women to know regarding why cervical cancer screening is so critical.