Cervical Cancer Screening – Pap Smear
Cervical cancer is cancer of the entrance to the uterus (womb). Globally, it is the 4th most common cancer amongst women. (1)
Women, in particular those who have been or are currently sexually active should undergo regular screening for cervical cancer.
To understand the importance of regular cervical cancer screening, let us first understand how cervical cancer develops.
Cervical cancer usually develops slowly over time.
It often starts out when a group of cells at the cervix start to display an abnormal appearance. They are also known as “pre-cancer” cells. Research has shown that in more than 90% of cases this process is caused by a virus called the Human Papilloma Virus. (2) There are more than 100 strains of HPV virus, of which it has been found that 13 of them can cause cervical cancer; in particular, the high risk types being 16 and 18. (3) HPV infection is very common in both men and women and most people are not aware that they carry the virus. It is passed on easily during sexual contact.
During the pre-cancerous stage, a woman usually would not experience any symptoms.
Over time, the abnormal cells increase in number and grow out of control and gradually take over more healthy tissue to form cancer, which can spread deeper into the cervix and even to surrounding areas and other organs. (4)
To significantly lower your risk of cervical cancer and safeguard your health, there are 2 important things you should do:
- Take the cervical cancer vaccination
- Have regular screening – it allows for early detection and prompt intervention
Cervical cancer screening is done through the following:
- Pap smear – to detect pre-cancerous changes or early cancer
- HPV testing – to identify women who are infected with HPV and therefore at high risk of developing cervical cancer
Who should have cervical cancer screening?
All women who have ever been sexually active can potentially develop cervical cancer. This is regardless of family history.
Also, women who have completed their cervical cancer vaccination should still undergo regular screening.
- Women 25 to 29 years of age should undergo a Pap smear every 3 years
- Women 30 to 69 years of age should have HPV testing every 5 years (5)
- Alternatively, some women 30 and over may choose to do both a Pap smear and HPV testing (co-testing) every 5 years
In general, cervical cancer screening via HPV testing is recommended only for women aged 30 and above. This is because there is a high rate of HPV detection among women before the age of 30, which often leads to further testing and unnecessary interventions, even though approximately 90 percent of HPV infections would eventually clear on its own. (6)
A woman can be discharged from screening at 69 years of age if she has:
- 3 consecutive negative Pap smear tests or
- 2 consecutive negative HPV tests or co-testing in the last 10 years, with the most recent test being done within the last 5 years (7)
Exceptions to the above recommendations on stopping screening may apply for those who had previously been found to have certain types of precancerous changes. Your doctor will advise you accordingly.
Women who are at higher risk of HPV and therefore cervical cancer:
- Having had multiple sex partners
- Weakened Immune System- e.g. HIV patients, autoimmune diseases, those on immune suppression drugs, organ transplant patients
- Patients who fall under this category should check with their doctor as their screening routine differs from the general population. (8,9)
In the rest of this article, we shall discuss about Pap smears in greater detail.
What is a Pap Smear?
A Pap smear is a quick procedure which involves your doctor using a brush to collects cells from the cervix to look for early cancer or abnormal cells that have a higher likelihood of developing into cancer in the future.
The Pap test may also detect inflammation changes and vaginal infections such as certain bacteria and yeast.
The Pap smear is not used as a screening test for endometrial cancer. However, occasionally the results may inform us about an abnormality of the endometrium- the lining of the uterus. (10)
How to prepare for a Pap smear?
Avoid vaginal intercourse for at least 2 days before your test.
Avoid using vaginal medications, creams, spermicides, lubricants, tampons or douching for at least 2 days before your pap smear, unless instructed by your doctor.
Shaving or removal of pubic hair before your appointment is not necessary.
To obtain a clean sample of cervical cells to prevent inaccurate results, a Pap smear should not be done just before, during or right after your menses.
Thus, schedule your Pap smear during this period: 2 weeks after the first day of your menstrual period, up to about a week before your next menstrual period is due.
If you prefer a lady doctor, do check with the clinic beforehand if a female doctor is available.
As you would need to undress from waist down, wear easily removable clothing on the day of your appointment.
Pass urine before the test: Pap smears may cause mild discomfort due to a sensation of pressure in the pelvic area. Urinating beforehand can relieve some of this pressure. In some cases, your doctor might require a urine sample for other testing purposes, thus check with the doctor or staff before going to the restroom.
The Pap smear is a simple and safe procedure conducted in your doctor’s consultation room. Most of the time it takes no more than a few minutes. Mild discomfort may be expected but the test usually does not cause significant discomfort or pain.
- For the doctor to perform the test, you will need to undress from waist down and lie on your back on the examination bed, with your knees bent and legs apart.
- A small disposable plastic instrument called a speculum is inserted into your vagina to allow the doctor to directly visualise the cervix, this ensure a good sample can be taken.
- Some patients may experience discomfort, pressure, or even slight pain during this part of the process. Your doctor will put an appropriate amount of lubricating gel on the speculum before inserting it into your vagina, to lessen any discomfort.
- It is also important to take deep breaths and try to relax your pelvic muscles during the process. Being tense would make you more likely to squeeze your pelvic muscles, which in turn would add pressure to your pelvic region and may cause more discomfort. Let your doctor know if there is significant pain or discomfort.
- A small disposable brush with soft flexible bristles is used to rotate against the middle of your cervix to collect a sample of cells.
- The cell samples are then sent to the laboratory for analysis.
- Usually, the results will be ready in 1 week.
It is not uncommon to have slight bleeding after a Pap smear, which normally resolves within a day or so. It may be a good idea to bring along a panty liner or small sanitary pad.
If, however, you are experiencing heavy or prolonged bleeding, or severe pain or cramps after the test, seek medical attention straight away.
Pap smear results
As previously mentioned, for those 25-29 years old, a Pap smear should be done once every 3 years, if results are normal. In the case of abnormal results, your doctor may advise you to repeat the Pap test in 6 or 12 months, or undergo a HPV test thereafter.
No abnormal or cancer cells seen. However, as with any lab test, Pap smear results are not accurate a hundred percent of the time and can fail to detect abnormal cells. But since cervical cancer usually takes more than a decade to develop from the pre-cancerous state (11), abnormalities can still be picked up on your next screening test. It is therefore crucial to have regular cervical screening as per the recommended schedule for your age. In addition, even if the last Pap smear result was normal, all women should seek medical help immediately if they develop any vaginal symptoms.
- Inflammation changes
Often caused by a fungal or bacterial infection. In most cases, your doctor will prescribe a course of medications to treat the infection and repeat the Pap smear in 6 months. If there is persistent inflammation after 2 repeat Pap smears despite treatment, you might need to see a gynaecologist for further evaluation with a colposcopy – a procedure where the cervix is examined under magnification for a closer look at areas of abnormality and sometimes tissue sampling (biopsy) will be performed.
- Atypical cells
The cells seen from the Pap smear were different or did not look entirely normal but did not meet the criteria to fall into the categories below.
It may be caused by a vaginal infection or HPV infection.
The laboratory may proceed with testing for high-risk HPV strains if such cells are seen.
If high risk HPV strains are present, this should be followed up with a colposcopy.
If high risk HPV is not found, the individual can return to the routine screening schedule.
- Low grade: cervical cells show mildly abnormal changes, that often will not need treatment.
- High grade: serious changes of the cervical cells which are more likely to progress to cancer and thus will usually require treatment (12)
In such instances where precancerous findings are seen, a colposcopy is needed. With high grade changes, the gynaecologist may even remove the abnormal tissues to prevent progression. The good news is that it often can be treated with simple procedures carried out in your gynaecologist’s office.
Abnormal cells that may have come from a cancerous lesion on the cervix. Urgent follow up with a Gynaecologist is needed. (13)
Prevention is always better than cure, therefore HPV vaccination and regular cervical cancer screening is of utmost importance!
- William, W., Ware, A., Basaza-Ejiri, A. H., & Obungoloch, J. (2019). A pap-smear analysis tool (PAT) for detection of cervical cancer from pap-smear images. Biomedical engineering online, 18(1), 16. https://doi.org/10.1186/s12938-019-0634-5
- Fang, W. H., Yen, C. F., Hu, J., Lin, J. D., & Loh, C. H. (2016). The utilization and barriers of Pap smear among women with visual impairment. International journal for equity in health, 15, 65. https://doi.org/10.1186/s12939-016-0354-4
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