Cervical Cancer Prevention
Annual Exams Matters
A gynecologic colleague told about an 80-year-old patient who stopped coming for her annual exam because she was told she did not need a pap smear. At her last annual exam 5 years ago, she had been prescribed a topical steroid for a chronic skin disorder that causes itching on the outside the vagina. She was seen by a urologist who recommended that she start using a low dose vaginal tablet for better bladder control. While her bladder got better, her vaginal itching persisted so she started using a topical estrogen cream that she had in her medicine cabinet, thinking the irritation was due to menopause. After several years of using daily low dose estrogen, she had a week of unexpected vaginal bleeding. Low dose estrogen can be placed in or around the vagina without any risk so long as the medicine is used only two times a week. She accidentally used too much low dose estrogen which led to uterine cancer. Surgery will cure her of this cancer, but this could have been avoided if she had been seen for her “annual” exam and a yearly review of her medications. I share this patient story to remind you about the importance of having your “annual” exam though they don’t always include a pap smear. This cancer diagnosis could have been prevented which is why I will review updated guidelines for gynecologic cancer prevention in the next few columns.
CERVICAL CANCER PREVENTION: Pap smears are a screen for precancerous changes in the cervix due to Human Papilloma Virus (HPV) infections that are acquired through sexual intimacy. Cervical cancer is a sexually acquired illness. The incidence of cervical cancer has decreased by 50% in the last 40 years due to pap smear screening. The role of HPV as the viral etiology for cervical cancer has evolved in the last 20 years. Most HPV infections are transient and poses little risk for progression. When HPV persists, a woman is at risk for cervical cancer. Most cases of cervical cancer (~60%) are in women who have never had a pap or not one in the last 5 years. Most young women under 21 years old, have an effective immune response that clears the majority of HPV infections in an average of 8 months or decreases the viral load to undetectable levels in 90% of women within 2 years. Risk factors for persistent HPV infection and therefore cervical cancer include infection with high risk virus i.e. HPV 16 or 18, tobacco use, multiple intimate partners. Pap smear specimens that are sent in a liquid medium have the advantage of allowing a single specimen to be used for the pap smear interpretation as well as testing for HPV and other infections like gonorrhea.
Risk reduction can start with abstinence and monogamy in addition to being vaccinated to prevent HPV viruses from being able to cause an infection in the first place. HPV vaccination became available in 2006 and an extended spectrum vaccine was introduced in 2014. The vaccine is approved for females and males between the ages of 9-26 but despite recommendations, only 50% of girls aged 13-17 in the United States have received at least one vaccine dose, only 33% have received all three doses. To be clear, this is a vaccine that prevents cancer and is very safe and efficacious.
The American College of Ob/Gyn (ACOG) recommends that women start getting pap smears at 21 years old and then repeated every 2-3 years. This recommendation is based on low incidence (0.1%) of cervical cancer in women under 21. Since most HPV infections (~90%) are cleared within 2 years, persistent precancerous cells which lead to cervical cancer is not as common as you think. Women between 30-65 years should get pap every 3-5 years and can include a primary screen for HPV. Women older than 65 years may stop pap’s if they have had three normal pap smears in the prior 10 years and are in a long term monogamous relationships. Women without a prior history of abnormal pap’s, who have undergone a hysterectomy that included the removal of their cervix can stop getting pap smears. These are general guidelines but how often you need a pap smear should be individualized with you by your doctor.
While it is no longer recommended that a woman gets a pap smear every year, it is still recommended that you be seen every year for your “annual exam.” This allows for complete review of your gynecologic health, medication risk and benefits, and updated recommendations on preventing cervical cancer and other gynecologic cancers like ovary and breast, which I will talk about next month.