Cervical Cancer Screening and Prevention
In the past 40 years, there has been a significant decrease in both the number of cases and the number of deaths associated with cervical cancer. In the 21st century, cervical cancer is one of the few malignancies that is now considered a preventable disease. This is possible through early detection programs and/or vaccination. Despite all of this, 12,280 women were diagnosed with cervical cancer in 2007 and 4,021 deaths occurred as a result of this disease. Although this still seems like a large figure for a highly preventable cancer, it is far less than what we have seen in the past and is no longer one of the most common cancers in women in the United States. By contrast, there will be an estimated 226,870 cases of breast cancers diagnosed, leading to 39,510 deaths in 2012. Unfortunately, cervical cancer still remains a significant problem in parts of the world that are less economically fortunate. Due to this, worldwide, cervical cancer still remains one of the most common cancers in women accounting for 275,000 deaths in 2008.
We have known for many years that there is a link between various degrees of sexual activity and cervical cancer. Recently we have been able to identify that up to 99% of cervical cancers are associated with certain types of the human papilloma virus (HPV). This virus is considered a sexually transmitted disease.
There are also other factors that can increase your risk for cervical cancer. These include: smoking, HIV infection, extended birth control use as the only means of contraception, and having given birth to over three children.
Symptoms of cervical cancer include abnormal vaginal discharge or bleeding.
It is widely accepted that cervical cancer screening has successfully decreased the development of cervical cancer and mortality associated with it. Recent advances in the link between HPV and cervical cancer has helped us further this cause. HPV is a sexually transmitted virus to the genital area. There is a strong association between HPV and development of cervical cancer. One study showed the presence of HPV in 93% of tumor specimens. HPV 16 was present in 50% of the specimens, HPV 18 in 14%, HPV 45 in 8%, and HPV 31 in 5%. HPV 16 was the predominant type in all countries except Indonesia, where HPV 18 was more common.
Based on this information, recent research has shown the benefits of HPV vaccinations. However, only certain age groups qualify for this vaccination. Ideally the vaccine should be administered before there is any exposure to genital HPV through sexual intercourse. The benefits of this vaccine decrease with increasing numbers of sexual partners. Routine HPV vaccination is recommended for females aged 11 to 12 years. Of note is that girls as young as 9 years of age may start the HPV vaccination series. HPV vaccination is also recommended for females aged 13 to 18 years to catch up on a missed vaccine or to complete the vaccination series. Although it is still safe to receive this vaccine after the age of 26, there is no evidence thus far of any benefit in this age group. Therefore, as it now stands, the HPV vaccine is not routinely recommended after the age of 26. Based on what we know so far there is also no benefit to men receiving this vaccination. These recommendations may change in the future as more research is done.
Based on the advances in cervical cancer screening, review of years of data on this subject, and recent information regarding the role of HPV in cervical cancer, the screening guidelines were recently updated. In March 2012, the American Cancer Society released these new guidelines for cervical cancer screening. The whole idea behind cervical cancer screening is to detect cervical cancer in its earlier stages in patients who do not yet show signs of cervical cancer. In recent years, due to this early detection, physicians have been able to diagnose and treat cervical cancer at much earlier stages thus increasing the potential for cure.
At the present time, there are two different types of screening modalities utilized: a pap smear and the HPV test. A pap smear is a method for detecting cells suspicious for turning into cancer or for detecting cervical cancer in its early stages. The HPV test can detect the certain strains of viruses that are known to eventually develop into cervical cancer.
The latest screening guidelines from the American Cancer Society now recommend that all women should begin cervical cancer screening at the age of 21. The most drastic change is that yearly pap smear are no longer required, since we now know that it can take years for cervical cancer to develop. More frequent testing can in turn lead to further unnecessary procedures. Women between the ages of 21 and 29 should undergo a pap smear every 3 years. In this age group, the HPV test should be performed only if the pap smear shows any abnormalities. A pap smear along with the HPV test should be performed every 5 years for women between the ages of 30 and 65. In this age group, if the HPV test is not done, then a pap smear should be done every 3 years. If a woman has had normal screening results, she no longer needs screening for cervical cancer after the age of 65.
Despite what we know of the benefits of the HPV vaccine for prevention of cervical cancer, the screening recommendations remain the same in a woman who has received this vaccine. This means that a woman who has received this vaccine must still continue to have screening the same as any women who never received such vaccine.
Despite the less frequent testing recommended in these new guidelines, women who are in the high risk category still need to be screened more often. The high risk category includes women who have had exposure to an agent called DES, those who have an HIV infection, those who have had a history of an organ transplant, and those who participate in excessive promiscuous sexual activity with multiple partners.
Additional posts by Kashif Ali, MD
- Ovarian Cancer – An Overview and Update, 31 Jan 2013 in Health & Wellness
- The Effects of Genetics on Breast Cancer: An Update, 13 Aug 2012 in Health & Wellness