By Mary Wellhoner, MD
At this point most women have heard of HPV, or human papillomavirus, but need guidance in understanding how it applies to their individual gynecologic care. Confusion abounds regarding how frequently Pap smear testing should be done, partly because as new information becomes available, protocols for testing are rapidly evolving. In addition, many women equate their yearly exam with the Pap test, but even if Pap and/or HPV testing is not needed every year, an annual visit and exam is still recommended for other preventive care: breast and colon cancer screening, birth control, STD screening, to name just a few, and many women benefit from getting their questions answered and their health concerns addressed.
As far as the Pap smear itself, in a nutshell, currently the recommendations are to start Pap smears at age 21. For sexually active women under 21, we recommend yearly and as needed screening for sexually transmitted infections, which are common in the younger age groups. Women between 21 and 30 need a Pap smear every three years. If their Pap smear is abnormal, then HPV testing will also be done on the sample. For women over 30, testing with both Pap and HPV should be done; if both are negative, co-testing with both Pap and HPV can safely be repeated in three years in most cases.
There is a lot to talk about here, but to begin to understand what HPV means to you, we need to get back to some of the basics about Pap smears. Pap smears were developed many decades ago as a screening test for cervical cancer. Unfortunately they don't detect other types of gyn cancer such as ovarian or endometrial cancer, but they have drastically reduced deaths from cervical cancer in parts of the world such as the United States were women are able to be screened regularly. The wonderful thing about the cervix is that we can actually see it, so we can detect cancer before it becomes advanced, unlike ovarian cancer, for instance, which remains hidden. In fact, the Pap smear is meant to detect precancerous changes, or dysplasia, so they can be treated before they even turn into cancer, similar to treatment of a superficial skin cancer before it invades under the surface.
With that being said, the Pap smear is only a screening test. It is a scraping of surface cells from the cervix, not a true biopsy, so it can sometimes miss things and it is not exact. If the Pap smear detects abnormal cells, we have to do actual small tissue biopsies of the cervix with a procedure called colposcopy to get the real story. Though Pap smears have improved somewhat over the years, they still have a very high false negative rate, which means they can miss things – as often as 30 or 40 percent of the time. Traditionally this is the main reason that we did the Pap smear every year. Cervical dysplasia does not grow very quickly, but doing the test every year helps to eliminate the problem of false negatives; in other words, if we miss it this year, we will probably catch it next year.
Enter HPV virus. We have known for at least 30 years that almost all cervical cancers are caused by the human papilloma virus, which is sexually transmitted but very common. (At least 50 percent of asymptomatic men are carrying and HPV virus.) So while Pap smears collect actual cervical cells to see if they are starting to look cancerous under the microscope, now we also have a test to detect the HPV virus. Some studies even show that testing for HPV alone may be more accurate than the Pap smear, but current recommendations revolve around some combination of these two tests.
Scientific knowledge about the HPV virus has grown exponentially in recent years. We now know that there are over 100 different types of the virus. Some of these types are associated with the development of cervical cancer and some are not. Currently when we do an HPV test, we are only testing for this group of the high-risk types of virus. In addition, we also now know that about 70% of cervical cancers are associated with just two types of the virus, types 16 and 18, and just in the past year we now have the ability to detect whether you have one of these very high risk types.
Most women have been exposed to some HPV viruses. While there is no cure for the virus, most of the time your immune system is able to clear the virus from your system within 2-3 years so that it is no longer detectable. It is only those women who aren’t able to clear it and who continue to have persistent high-risk virus in their system that are at risk for cervical cancer down the road. So it is generally those women with persistent high risk HPV, and particularly types 16 and 18, that are most at risk for eventually developing cervical cancer.
While there is more to talk about here, such as the HPV vaccine, this is getting long and will have to be continued next time. While current recommendations revolve around co-testing every three years for unaffected women, your individual screening plan depends on your personal history and risks and should be discussed with your provider. Regardless of Pap smear and HPV testing, women of all ages benefit from a yearly visit with a women’s health provider, and the new Health Act provides payment for this preventive visit without co-pay or deductible. “An ounce of prevention is worth a pound of cure.”
At this point most women have heard of HPV, or human papillomavirus, but need guidance in understanding how it applies to their individual gynecologic care. Confusion abounds regarding how frequently Pap smear testing should be done, partly because as new information becomes available, protocols for testing are rapidly evolving. In addition, many women equate their yearly exam with the Pap test, but even if Pap and/or HPV testing is not needed every year, an annual visit and exam is still recommended for other preventive care: breast and colon cancer screening, birth control, STD screening, to name just a few, and many women benefit from getting their questions answered and their health concerns addressed.
As far as the Pap smear itself, in a nutshell, currently the recommendations are to start Pap smears at age 21. For sexually active women under 21, we recommend yearly and as needed screening for sexually transmitted infections, which are common in the younger age groups. Women between 21 and 30 need a Pap smear every three years. If their Pap smear is abnormal, then HPV testing will also be done on the sample. For women over 30, testing with both Pap and HPV should be done; if both are negative, co-testing with both Pap and HPV can safely be repeated in three years in most cases.
There is a lot to talk about here, but to begin to understand what HPV means to you, we need to get back to some of the basics about Pap smears. Pap smears were developed many decades ago as a screening test for cervical cancer. Unfortunately they don't detect other types of gyn cancer such as ovarian or endometrial cancer, but they have drastically reduced deaths from cervical cancer in parts of the world such as the United States were women are able to be screened regularly. The wonderful thing about the cervix is that we can actually see it, so we can detect cancer before it becomes advanced, unlike ovarian cancer, for instance, which remains hidden. In fact, the Pap smear is meant to detect precancerous changes, or dysplasia, so they can be treated before they even turn into cancer, similar to treatment of a superficial skin cancer before it invades under the surface.
With that being said, the Pap smear is only a screening test. It is a scraping of surface cells from the cervix, not a true biopsy, so it can sometimes miss things and it is not exact. If the Pap smear detects abnormal cells, we have to do actual small tissue biopsies of the cervix with a procedure called colposcopy to get the real story. Though Pap smears have improved somewhat over the years, they still have a very high false negative rate, which means they can miss things – as often as 30 or 40 percent of the time. Traditionally this is the main reason that we did the Pap smear every year. Cervical dysplasia does not grow very quickly, but doing the test every year helps to eliminate the problem of false negatives; in other words, if we miss it this year, we will probably catch it next year.
Enter HPV virus. We have known for at least 30 years that almost all cervical cancers are caused by the human papilloma virus, which is sexually transmitted but very common. (At least 50 percent of asymptomatic men are carrying and HPV virus.) So while Pap smears collect actual cervical cells to see if they are starting to look cancerous under the microscope, now we also have a test to detect the HPV virus. Some studies even show that testing for HPV alone may be more accurate than the Pap smear, but current recommendations revolve around some combination of these two tests.
Scientific knowledge about the HPV virus has grown exponentially in recent years. We now know that there are over 100 different types of the virus. Some of these types are associated with the development of cervical cancer and some are not. Currently when we do an HPV test, we are only testing for this group of the high-risk types of virus. In addition, we also now know that about 70% of cervical cancers are associated with just two types of the virus, types 16 and 18, and just in the past year we now have the ability to detect whether you have one of these very high risk types.
Most women have been exposed to some HPV viruses. While there is no cure for the virus, most of the time your immune system is able to clear the virus from your system within 2-3 years so that it is no longer detectable. It is only those women who aren’t able to clear it and who continue to have persistent high-risk virus in their system that are at risk for cervical cancer down the road. So it is generally those women with persistent high risk HPV, and particularly types 16 and 18, that are most at risk for eventually developing cervical cancer.
While there is more to talk about here, such as the HPV vaccine, this is getting long and will have to be continued next time. While current recommendations revolve around co-testing every three years for unaffected women, your individual screening plan depends on your personal history and risks and should be discussed with your provider. Regardless of Pap smear and HPV testing, women of all ages benefit from a yearly visit with a women’s health provider, and the new Health Act provides payment for this preventive visit without co-pay or deductible. “An ounce of prevention is worth a pound of cure.”