Guide to cervical cancer screening (pap smear), from preparation to results

 Key takeaways:

• Cervical cancer is the fourth most common cancer in people with cervix, and it kills thousands every year.
• A pap smear can be used to detect abnormal cells in the cervix before they progress to cervical cancer. 
• Preparing for cervical cancer screening may involve avoiding vaginal sex, douching, and putting medicines or creams in the vagina two days before a pap smear. 
• Healthcare professionals typically recommend a pap smear every three years, from age 21 to 65.

Cervical cancer is the fourth most common cancer affecting women worldwide. It’s the second-leading cause of cancer deaths in women, with up to 660,000 new cases and 350,000 fatalities recorded in 2022. About 94% of these deaths occurred in low- and middle-income countries.

Certain strains of the human papillomavirus (HPV), particularly HPV 16 and 18, are predominantly responsible for the development of cervical cancer. Persistent infections by these strains of the virus, classified as high-risk types, are implicated in about 70% of all cervical cancer cases.  

HPV is the most common sexually transmitted infection in the United States. It’s so common that experts estimate that nearly every sexually active person will acquire an HPV infection at some point in their lives. However, the immune system typically clears off the infection, so it causes no symptoms and doesn’t progress into cancer for some people.  

Unfortunately, in some cases, the immune system is unsuccessful in resolving the infection. If HPV persists in the cervix and is left untreated, it causes abnormal changes in cells, which may eventually become cancerous.

Depending on one's immune system, it may take between 5 and 20 years for these abnormal cells to progress to full-blown cancer.  A Papanicolaou test, more commonly called a pap smear, can aid in the early detection of these abnormal cells before they become cancerous.

 What is a pap smear, and what is it used for?

A pap smear is a procedure used to detect cervical cancer in women. It involves the collection of cells from the cervix. These cells are then sent to a laboratory for examination under a microscope to detect the presence of cancer cells or abnormal changes that can lead to cervical cancer.

Your doctor may also request a pap smear to help diagnose infections or other inflammatory conditions. This exam may be performed in the doctor’s office while you get a pelvic exam or during HPV tests. 

 What to expect during a pap smear

Pap smears may be uncomfortable for some, but the procedure may be more bearable if you know what to expect. It’s usually done in your doctor’s office, clinic, or community health center.

Your provider begins by asking you to remove your underwear and lie on an examination table. You may be asked to lie on your back, bend your knees, and keep your feet on a support at the end of the examination table.

The next step is the insertion of a speculum into the vagina to separate the vaginal walls. This allows the doctor to see your cervix clearly. A small, soft brush is then inserted into the vagina to collect a few cells and mucus from the cervix. Finally, your sample is sent to the laboratory to be viewed under a microscope. 

 How to prepare for a pap smear

To get accurate results, take the following precautions about two to three days before a pap smear.

• Don't have vaginal sex. 
• Avoid using water or other feminine wash to rinse out your vagina (douching).
• Avoid putting creams, medicines, or anything else in your vagina. 
• Avoid spermicidal or birth control foams.

 Who needs a pap smear, and how often should it be done?

Pap smears are generally recommended for women aged 21 to 65, but depending on certain factors, older age groups may also be included. However, women above 30 might be asked to get a pap test and HPV test together or separately. 

If you have a normal pap smear result and are between 21 and 65 years old, your doctor may ask you to wait three years to schedule your next appointment. Additionally, your doctor might suggest waiting up to five years for another pap test if your HPV test or combined HPV test and pap smear turned out normal.

If you're older than 65, your doctor may tell you that you don't need any more pap smears if:

• You've had three consecutive normal pap smear results and two negative HPV tests in the past ten years. 
• You've not had any precancerous cells in your cervix.
• Your cervix was removed for noncancerous conditions like fibroids.

Some people may need to continue performing pap tests even after turning 65 or more frequently than every three years. Conditions that necessitate more regular pap smears include:

• You have the human immunodeficiency virus (HIV).
• Your last pap smear result was abnormal. 
• You have a weak immune system. 
• In the womb, you were exposed to diethylstilbestrol (DES), a female form of the female hormone (estrogen) before you were born. 

 Understanding your pap smear result

Your pap smear result may come out as:

 Normal pap smear result

A normal or negative pap smear result means that no cancer cells or abnormal cell changes are present. As a result, you may only need to come back in three years for your next appointment or five years if you also had a negative HPV test. 

 Unclear pap smear result

An unclear pap smear result is pretty common. This means the cells look a little unusual, but there's not enough evidence to show that these changes are due to HPV. Multiple other factors, like menopause, pregnancy, inflammation, or infection, can cause changes in the appearance of the cervical cells.

To rule out any serious cause of the cell changes, your doctor might ask you to perform additional cervical cancer screening tests, like the HPV test.

 Unsatisfactory pap smear result

Unsatisfactory pap smears mean the doctors were unable to harvest enough cells to get a clear picture of the state of your cervix. In this case, a repeat pap smear in the next few months may be required.

 Abnormal pap smear result

An abnormal pap smear result means your provider identified cells with abnormal changes caused by HPV. Minor or low-grade changes may sometimes revert to normal. On the other hand, serious or high-grade changes can progress into cancer. 

Your doctor may request further tests if the pap smear results are abnormal. This includes directly viewing the cervix with a colposcope. If the colposcopy reveals abnormal areas, a biopsy (taking out a small part of the cervix for further examination) may be done.

In the event that the biopsy shows evidence of precancerous cells, your doctor will treat you with a range of procedures. This may range from either burning or removing all or part of your cervix to the removal of the whole uterus, depending on your circumstances and reproductive intentions.

 Final thoughts

Cervical cancer is a preventable cancer, yet it kills thousands of women each year. It’s mainly caused by persistent infection by high-risk human papillomavirus strains.

Regular pap smears help detect abnormal cells or cervical cancer early, allowing for quick and effective treatment. 

Women between 21 and 65 are encouraged to go for routine pap smears. Your doctor might add other screening tests like HPV tests or colposcopy, depending on your pap test results.