Even though there is a ton of information out there there is still a lot of confusion on what is a pap smear, who needs it, how often we should have it, and what is it actually checking. Here are a few things to try to clarify some of these doubts.
What and where is the cervix?
The cervix is the tunnel-like structure at the lower part of the uterus. It is sometimes called the “neck” of the womb as it connects the main body of the uterus to the vagina and allows passage of fluids between them.
What is Cervical Cancer
Cervical Cancer is the 4th most common cancer in women worldwide. In the US over 13,000 women are diagnosed each year and 4,000 women die from it yearly. Low- and middle-income countries have even higher rates of both prevalence and mortality due to poor access to preventative measures like pap smears and HPV vaccination.
How to detect Cervical Cancer – The Pap Smear and HPV test
Screening can detect early-stage disease of cervical cancer. Currently there are three ways to test: the pap smear, testing for the high risk human papillomavirus (HPV) or co-testing.
- The Pap smear, Papanicolaou test or cervical cytology is a procedure to screen for cervical cancer. It has been the most successful cancer screening program in history. It gently removes cells from the surface of the cervix so they can be checked under a microscope for precancerous or cancerous changes. In the past and in some developing countries the conventional pap is used where the sample is smeared into a microscope slide after collection. Since this method is less accurate, more frequent screening might be needed. Most places nowadays use liquid-based cytology where the sample is placed in a bottle of preservative. This has better transfer, improves fixation, removes obscuring factors and is analyzed using pap stains that help differentiate the different types of cells. It may also use automated slide interpretation to select slides for further review by a cytopathologist.
- In addition to the pap smear, testing for HPV DNA is possible at the same time as the pap smear. Over 95% of cervical cancers are caused by HPV. There are over 200 types of HPV virus with some considered higher risk (like 16 and 18 accounting for 80%) for cervical cancer.
- Co-testing with pap smear and HPV together identifies 94.1% of cervical cancers and 99.7% of pre-cancers which is higher than either pap alone or HPV Alone.
Why is it important to screen for cervical cancer
- Reduces mortality – Since the introduction of the pap smear in 1941, the rate of cervical cancer has decreased over 70%. It used to be the leading cause of cancer death in women but now it has dropped to be the 15th most frequent!
- Reduces incidence by detecting pre-cancerous cells.
- Since the development of the Pap test, Co-testing with the HPV-DNA test increases detection rate which is why the latest guidelines in most developed countries with access to co-testing recommend screening every 3-5years depending on age and risk factors. Detecting cervical cancer early gives a better chance at a cure.
What are the potential harms
We cannot discuss the importance of the pap smear without also mentioning the potential harms.
- Risks of treatment on pregnancy outcomes – treatment with ablation or excision have been linked to infertility due to scarring, increased pregnancy loss, preterm delivery, preterm premature rupture of membranes, perinatal mortality.
- Patient discomfort – choosing a provider that understands and respects the experience for each woman and does within what is possible the best attempt at minimizing discomfort.
- Psychosocial consequences – there are high levels of anxiety associated with the test itself but also with abnormal results, the need for colposcopy and further surveillance for mild abnormalities, as well as high anxiety and confusion with HPV infection. Women with history of sexual abuse may even be at a bigger impact. Finding a sensitive examiner with good bedside manner and technique will help ease the process.
- Rising health care costs – There are monetary costs associated with the result of screening that leads to further testing, biopsies and increased surveillance testing. However there are opportunity costs where some private practitioners may take benefit for more frequent testing or testing women where it is not recommended.
- False-positive results
Who should have a Pap smear
Different countries may have slightly different guidelines depending on the type of test available and how accessible it is. In the US different organizations have made similar recommendations which include screening women with average risk factors include:
- Women 21 to 65 should be screened regardless of initiation of sexual activity or high risk behaviors. However, you and your doctor can decide when is the best time for you to begin testing.
- Women with abnormal pap smears or cervical cancer may need more frequent screening
- Women with HIV infection may need more frequent screening
- Women with unexplained vaginal bleeding or bleeding after intercourse
Who should NOT have a Pap smear
- Women under 21 years of age
- Women with hysterectomies for reasons other than cancer
What are some risk factors
There are some individual cases that may increase the risk of cervical cancer and the timing of screening may change. These include:
- Contracting human papilloma virus (HPV)
- Abnormal pap smear
- Smoking
- HIV or AIDS
- Exposure to diethylstilbestrol (DES) before birth
- Immunosuppressed women (weaker immune system) – Includes women on cancer treatment, on steroids or immunotherapy for autoimmune disease or with organ transplants
- Using birth control pills for over 5 years
- Giving birth to 3 or more children
- Having multiple sex partners
Step by Step
1. You will be asked to lie down on an exam table in what is called a lithotomy position where the legs are bent at 90 degrees at the hip and knees and feet are held by foot rests. Tip: The further down you go on the table without falling, where you are hanging a little, helps your uterus tilt in a way that it’s easier for the examiner to look at your cervix. For some people making a fists under the tailbone helps to tilt even more. Some women have retroverted uteri and the cervix may be harder to find so I always let my patients know where it is so they can guide a future examiner.
2. A plastic or metal speculum will be inserted into the vagina in a closed position. Most of the time it will be lubricated for comfort. Tip: There are different size specula. I try to use the smallest possible although most women may tolerate a medium size. If you know you have vaginal dryness, have not been sexually active for a long time or just know it is a bit narrow, request a small speculum. Conversely, if you know your cervix is very deep, request a longer speculum. Both ways will avoid too much moving of the speculum, having to switch it and may help minimize discomfort.
3. Once the speculum has been introduced it will be opened to visualize the cervix.
4. A broom-like brush will be inserted into the vagina to collect cells from the cervix.
5. The sample is then placed in a solution (if liquid-based is available) where it is taken to the lab to look under the microscope for signs of disease.
After the pap smear
Based on the results you will be guided into the next step. Remember they are looking at both the cells (cytology) and the HPV status. Here are some (but not all) the possibilities:
- Cytology normal, HPV negative – will need follow up in 3-5 years depending on age.
- Cytology normal, HPV positive – may need follow up in 1 year or colposcopy depending on type of HPV or previous history
- Abnormal pap, HPV positive – will frequently require a colposcopy
- Abnormal pap, HPV negative – depending on how severe the abnormality is or the age either a follow up in 1 year or colposcopy will be recommended
Whether you are new to pelvic exams and cervical cancer screen or you have had them in the past I hope this information is useful. The most important is that you understand what is happening to your body, why is important to screen and when is not necessary and also that you find someone who is respectful and sensitive to this exam and listen to your needs.
