Women’s health preventive cancer screening: pap smears

Sharon McNeill MD August, 2015

Medicine changes quickly. Over the course of my (short) 11 years in training and practice there have been great advances in many areas! However, sometimes with these changes, we fail to explain the reasons behind the change & the benefit of the new advancement to the general public… and it can lead to anxiety for our patients, as well as long discussions in the office. My hope is to explain current thoughts on preventive health screenings— starting with women’s health: pap smears, mammograms… and moving into general recommendations for everyone. Remember, medicine changes- we learn, we correct and we amend based on new information; so for 2015- here are the current thoughts and recommendations.

Why do we care about cervical cancer?
In the US every year there are about 13,000 new cases of invasive cervical cancer and 4,100 deaths related to cervical cancer. With the help of Pap smear screening – In developed countries over the past 50 years we have seen a 75% reduction in cervical cancer! Unfortunately, worldwide over half a million cases are still diagnosed every year and around 260,000 women die. In developing countries, cervical cancer is still the 2nd most common cancer in women and is the 3rd most common cause of cancer death… We have work to do!

What is a Papanicolaou ‘Pap’ smear?
The Papanicolaou stain was developed by Dr. George Papanicolaou in the early 1920s. It is useful for looking at many different types of cells we most commonly hear about it in relation to the “Pap smear”. This test takes a sample of cells from the outer (and inner, depending on the quality of the sample) cervix. In the past, the sample was immediately ‘smeared’ onto a slide and sent to the pathologist to look at the cells under the microscope. Today, most often these cells are placed into a liquid preservative solution and the cells are placed on a slide once they arrive in the lab. This newer method also allows testing for HPV on the same sample.

In addition to getting information about the cervical cells themselves, the pathology report also gives us information on the quality of the sample we collected, what types of cells were seen and comments about inflammation or infections that were picked up. This is not a great way to do sexually transmitted infection screening, but sometimes we do find something. The cervix has two kinds of cells: squamous and glandular; there can be abnormalities in either or both.
Below are the different results we may get back regarding the squamous cells:
Negative for intraepithelial lesion (normal)
Atypical squamous cells of uncertain significance (cells look a little funny, but not in a concerning way)
Atypical squamous cells- cannot exclude high grade lesion (cell look funny, with concerning features)
Low grade cervical intraepithelial lesion (mild pre-cancerous changes)
High grade cervical intraepithelial lesion (moderate to severe pre-cancerous changes)
Squamous cell carcinoma (cancer)

The glandular cells can be endocervical, endometrial or simply ‘glandular;’ since we don’t always see these on a pap smear, there is often no specific comment. Below are the findings we get back if the pathologist notices something worth mentioning:
Atypical
Atypical, favor neoplastic (some features that look like cancer)
Adenocarcinoma in situ (cancer that hasn’t become invasive)
Adenocarcinoma (cancer)

By screening women at regular intervals we can pick up pre-cancerous changes and treat it before invasive cancer develops. Did you catch that? By doing a Pap smear and picking up early changes we can PREVENT cancer! Can you imagine if we had this ability in lung or breast cancer? The Pap smear has truly been a game changer for women around the globe!

What about HPV screening?

First of all, what is the Human Papilloma Virus (HPV)?
This is a family of DNA viruses- first discovered to be the likely cause for cervical cancer in the early 1980s. There are more than 40 types – some that rarely cause any problems, others that lead to warts and still others that can lead to cancer. HPV 16 and 18 cause about three quarters of the world’s cases of cervical cancer while other high risk strains account for nearly all of the rest. It doesn’t just affect women; warts and cancers can affect the mouth, throat, penis, anus— any area where the virus has direct contact. HPV is the most common sexually transmitted infection. It is estimated that 80% of people will be infected with at least one strain in their lifetime. Depending on the strain of HPV and a person’s overall health, it may take 10 or more years for an infection to lead to cancer.

The first HPV DNA test was approved in the US in 1999. Since then, the tests have become more sensitive and detailed and can tell us not only if there is an HPV infection, but also if it is one of the high risk strains.

Now that we have the ability to detect HPV BEFORE there are precancerous changes on a pap smear, we can closely monitor women at higher risk for developing cancer and do screening less often for women at low risk. THIS is why we have been able to stop routine annual pap smears and for some women screen as infrequently as every 5 years!

Screening guidelines:
It’s more important than ever to have a primary care provider or gynecologist keeping track of you! Each person truly is unique in their risks and need for Pap smear screening. It used to be that all women were screened every year starting at the time of first sexual contact. We now know that people are able to recover from HPV infections and that pre-cancerous changes can return to normal! Giving the body time to heal before we jump to screening prevents unnecessary anxiety and treatments. We now routinely start screening at age 21.
For low risk women, pap screening is recommended every 3 years until age 30. We add on HPV testing for women age 25-29 if their pap smears come back abnormal. After age 30 for low risk women, we do both HPV and Pap smear testing every 5 years! This generation of young women will have far fewer pap smears than their mothers did while still experiencing lower rates of cervical cancer!

A word of caution: Screening is different than investigating. If you have symptoms of irregular bleeding, unexplained pain and frequent infections, you may then be screened before age 21 or have screening sooner than the usual 3-5 year intervals. If you have a history of abnormal pap smears or cancer, you will likely have more frequent pap smears for many years. Again, it’s important to know your history and have a doctor you trust keeping track of things too!
Future studies: In the future we may be doing fewer pap smears and more HPV testing. There is even hope for a urine-based HPV test! Make sure you have regular visits with your doctor so you can be aware of future updates!

Treatment: you have an abnormal pap smear &/or HPV infection, what is the next step?
You will want to have a discussion with your doctor about your specific results and risks of treatment. For many early changes, we simply watch more closely so you may have a repeat pap in 6 months or a year. For higher grade changes or changes that persist when we recheck, we do a simple procedure called a colposcopy. A colposcopy is done with the use of a colposcope, a microscope that can look directly at your cervix and vagina. Using this, along with different stains and colored lights, your doctor can look for concerning areas and take biopsies when necessary. Depending on the results of those biopsies, your doctor will discuss with you the options of a ‘watch and wait’ plan or immediate treatments. Cryotherapy (freezing abnormal cells), Loop electrosurgical excision procedure (LEEP), surgical conization or laser vaporization are all possible options depending on your particular case. If the cancer is severe, sometimes a hysterectomy, chemotherapy &/or radiation are needed (our goal is NOT to let it get to this point!)

Thankfully, our bodies heal! We estimate about 70% of HPV infections clear in 1 year and 90% by two years. Not smoking, eating a healthy diet (and maintaining a healthy weight) and limiting alcohol intake (or not drinking at all) will increase the chances of clearing the virus.

I don’t want to deal with this! What can I do to prevent HPV infection in the first place?
I’m glad you asked! The best methods we have for preventing HPV infection are:
• Vaccinate against the high risk HPV strains
• Practice safer sex by using condoms each and every time
• Limit the number of sexual partners

Of course, none of these methods will guarantee 100% protection, but together, they help tremendously! The CDC estimates that in the United State since the HPV vaccination first became available in 2006, teen rates of HPV have reduced by over 50%. We expect infection will continue to drop as more teens are vaccinated.

What is the story on HPV vaccination?
There are 3 approved vaccinations in the US:
• Gardasil
• Gardasil 9
• Cervarix
The newest Gardasil vaccine protects again NINE strains of HPV that commonly lead to cancer and warts. Numerous studies have shown no safety differences between HPV vaccination and placebo injection with saline- the most common side effects being minor injection site skin infections & irritation or fainting (felt to be due to mild pain or anxiety of the injection). Gardasil is seen as one of the safest vaccines we have ever made. And it is extremely effective as well! It appears that this vaccine is greater than 97.5% effective in producing antibodies, the proteins your body makes specifically to fight against the HPV strains it has been designed for. Antibody levels are detected for at least 8 years after receiving the vaccine series. There has been no evidence that teen sexual activity increases after the vaccine. The goal is to vaccinate boys and girls before sexual activity; before exposure to the virus. The vaccines are currently approved for the age range of 9-26, however there is good evidence that using the vaccines for older individuals is more than 90% effective at preventing cancer and the FDA is currently considering approving the vaccine for adults over 26. This vaccine PREVENTS cancer! In a time when we are looking for ways to cure cancer, we have an extremely safe and highly effective method for prevention! If you have not yet started or have only partially completed your vaccination series, please call us today to schedule a nurse visit & get caught up!

Summary:
Cervical cancer, thankfully, is not as crucial an issue as it was in the past due to advances in cancer screening, but awareness of it is still important. Most cervical cancer is caused by a virus that we can prevent with a vaccination! Following up with your doctor as directed for routine pap smears and/or HPV screening is extremely important!

References:
CDC website re: cervical cancer: http://www.cdc.gov/cancer/cervical/; HPV vaccination http://www.cdc.gov/hpv/vaccine.html and Human statistics: http://www.cdc.gov/mmwr/preview/mmwrhtml/mm63e1105a1.htm

The American Society for Colposcopy and Cervical Pathology guidelines: http://www.asccp.org/Guidelines

Should US Women be Screened for Cervical Cancer with Pap Tests, HPV Tests, or Both? Perkins, Rebecca MD, MSc and Stier, Elizabeth MD. Annals of Internal Medicine. 2014; 161:295-297

Screening for Cancer: Advice for High-Value Care From the American College of Physicians. Timothy Wilt MD, MPH et al., Annals of Internal Medicine 2015;162(10):718-725

HPV Vaccination for the Prevention of Cervical Intraepithelial Neoplasia. Kahn, Jessica MD, MPH The New England journal of Medicine 2009; 361 (3): 271-278

Safety of quadrivalent human papillomavirus vaccine administered routinely to females. Klein, NP et al. Archives of Pediatrics and Adolescent Medicine 2012; 161: 1140-1148.

Natural History of Cervicovaginal Papillomavirus Infection in Young Women. Gloria Ho PhD, et al. The New England journal of Medicine 1998; 338: 423-428

ACOG Committee Opinion No 463: Cervical cancer in adolescents: screening, evaluation & management. Obstetrics & Gynecology 2010; 116: 469-472.

Incidence of cervical cytological abnormalities with aging in the Women’s Health Initiative: a randomized controlled trial. Yasmeen, S et al. Obstetrics & Gynecology 2006; 108: 410-419.
Primary Cervical Cancer Screening with HPV: end of study results from the Athena study using HPV as the first-line screening test. Wright, TC et al. Gynecology Oncology 2015; 136: 189-97