Overview
Cervical cancers are among the most common cancerous (malignant) tumours. Fortunately, a large majority of women diagnosed with this disease are completely cured. This is because the tumours tend to grow slowly. Women are encouraged to have regular Pap tests, as this allows for early detection of tumours in most cases, and therefore plenty of time to treat them.
Girls and women aged 9 to 26 can also reduce their risk of cervical cancer by having the cervical cancer vaccine. Recommendations for Pap tests vary from province to province. All provincial programs target women between the ages of 18 and 69.
In a typical year, about 1,450 Canadian women are diagnosed with cervical cancer, and about 430 will not survive it. Most of those who die are in the oldest age groups, and almost all of them are people whose cancer had already spread before it was detected. This is only likely to happen if you don't have regular Pap smears done. The death rate from cervical cancer is now 90% lower than it was before the Pap smear was invented in 1941. The Pap test can actually tell in advance which people are likely to develop cervical cancer in the near future, allowing doctors to act to prevent the disease from appearing.
The tissues of the cervix are very prone to undergo abnormal changes, and many women have tumours or neoplasms (new growths) in these areas of the reproductive system. Only a minority of these changes are actually cancerous. Some are benign, which means that they won't multiply and spread to other organs, and therefore aren't cancerous. Others are considered precancerous, and may require surgical treatment similar to that used to cure cancer itself. Many women who don't actually have cancer still need to be treated by an oncologist (a doctor who treats cancer).
Preventing cancer may require a time-consuming series of diagnostic and surgical procedures. Similarly, women who have been cured of cervical cancer often need further treatment, especially if radiation was used. The latest prevention method is a vaccination against 4 common types of HPV. HPV, or human papillomavirus, is a sexually transmitted virus that can cause cervical cancer and other health problems. The vaccine prevents against the types of HPV that cause about 70% of all cervical cancers. It is a highly effective way to reduce the likelihood of developing a number of conditions caused by the human papillomavirus. The vaccination is available for girls and women 9 to 26 years of age.
Causes
We still don't fully understand what triggers cells to start dividing uncontrollably to form a tumour, but we have been able to observe certain patterns in people with cancer that tell us about risk factors.
Infection plays a major role in cervical cancer. The number one risk factor for cervical cancer is infection by the sexually transmitted human papillomavirus (HPV). Infection with HPV rarely leads to cervical cancer; infection is a common occurrence and the virus usually goes away by itself. However, it can remain and lead to cancer - and most cervical cancers are related to HPV. When cancer appears in the cervix, it's usually located at a site that's actively inflamed due to infection by this virus. Viruses insert their own DNA into human cells, altering their code. This may be what causes cells to multiply uncontrollably in cervical cancer.
It's been shown repeatedly that women who are young when they lose their virginity and women who have had many sexual partners are at higher risk of the disease. However, most people have been exposed to HPV in their lifetime.
People who smoke are at higher risk of this disease, as with most cancers. The risk also increases steadily with age. Women over age 65 are the most likely to develop cervical cancer. In Canadian studies, people with low incomes had consistently higher rates of cervical cancer. The most dramatic risk elevation was found in First Nations women, who are 2 to 6 times as likely to develop cervical cancer as non-Native women.
There's limited evidence that certain families have a higher risk of developing cervical cancer. It's likely that some cell types are more susceptible to HPV than others. Like many diseases, cervical cancer is probably caused by a combination of genetic and environmental factors.
Cervical dysplasia is a term that describes new growths of abnormal tissue that often appear in the cervix and sometimes forewarn of cancer. Today, a classification system called the Bethesda system is used to describe abnormalities on the Pap test. Although it is much more complicated than the previous system, it is more specific and exact with its details.
Symptoms
The Pap smear is an important test to have because abnormal cells and cancer of the cervix often produce no symptoms. The only symptom commonly seen is vaginal bleeding. This is most likely to occur after sexual intercourse, but any vaginal bleeding outside of normal menstruation should be investigated by a doctor.
Pain or a foul-smelling discharge may appear in late-stage cancer, but if these symptoms appear suddenly, without warning, it's far more likely to be an infection than a tumour. HPV infection typically produces no symptoms at all.
Treatment
Cervical cancers that are detected early enough - as most are nowadays - can be removed by surgery. The cure rate is very high, and only a small minority of cancers return after treatment. Nevertheless, a woman can expect to be monitored closely after successful treatment to make sure that the cancer is gone for good.
With larger cancers, more tissue must be removed. A tumour that's spread into the wall of the cervix usually requires hysterectomy (removal of the uterus). Small tumours can be treated with extrafascial hysterectomy, leaving some of the uterus (womb) intact. Somewhat larger tumours require radical hysterectomy, the complete removal of the uterus and cervix. If cancer has spread to nearby lymph nodes (a network of kidney-bean-shaped immune organs spread throughout the body), the affected nodes must be removed as well.
With more advanced tumours, doctors often recommend radiation therapy after surgery to kill any remaining cancer cells. Unfortunately, radiation can cause stenosis (closing) and dryness of the vagina. Regular stretching with a special device known as a dilator can help prevent vaginal stenosis. This can be done at home.
Very advanced or widespread tumours are often treated with radiation. In fact, cervical cancer can be cured by radiation alone, even when the tumour has spread.
In a few cases, the cancer has spread widely in the pelvis (i.e., to the bladder and rectum) but hasn't reached the lungs or other organs. Radiation therapy is usually tried first, but if this doesn't work, a surgical procedure called exenteration may be effective. Exenteration is a procedure in which all of the pelvic organs are removed, and the organs are replaced by artificial devices and grafts of the person's own tissue. This radical technique produces cure rates of about 50%.
The risk of cervical cancer can be greatly reduced if you avoid becoming infected with the papillomavirus. That said, the virus is a very common infection in both men and women, and only a very small percentage of infections cause any problems. Most people picked it up in adolescence or early adulthood, long before they or anyone else knew about its link to cervical cancer.
If you aren't infected, you can help stay that way by practising safe sex: use condoms. However, it's important to know that condoms only protect the areas that they cover. Since condoms do not cover all areas that may touch during sexual activity, HPV can still be spread by skin-to-skin contact even when someone is wearing a condom. Nonetheless, since condoms cover most of the genital areas that are in contact during sex, they reduce the risk of HPV even if they don't prevent it completely.
If you smoke, quitting will also improve your chances of avoiding cervical cancer.
Another way to prevent cervical cancer is through vaccination. The world's first vaccination against HPV was approved in Canada and the United States in 2006. The vaccination provides protection from 4 different types of human papillomavirus. In studies, it has proven to be very highly effective in preventing infection with 4 types of HPV that cause genital warts, cervical cancer, precancers of the cervix, and cancers of the vulva and vagina.
The vaccine is currently available for girls and women aged 9 to 26. Although the vaccine protects against future HPV infections, it does not affect existing infections in people with HPV. This means that girls who are not yet sexually active are the best candidates for the vaccine, since they have not yet been exposed to HPV. But women who are already sexually active can also benefit from the vaccine if they have not yet contracted HPV. The vaccination is given in 3 doses over a period of 6 months.
Other tips:
The way to test for cervical cancer is to use a Pap test, named not after the papillomavirus, but after the test's inventor, George Papanicolaou. Statistics suggest that Pap smears save the lives of at least 1,000 Canadian women each year. The test gives results that range from minor tissue inflammation due to hormones, to papilloma infection, abnormal cells, and cervical cancer. It can also sometimes detect uterine (endometrial) cancer. The test is simple and painless, involving no more than a gentle scrub with a small brush in the cervix.
If the results show abnormal tissue, the next step depends on the tissue's appearance. Some results are not quite normal but not very worrisome either. This is particularly likely around the time of menstruation, or in women who have some kind of genital infection other than papillomavirus. Your doctor may ask that the test be repeated after a few weeks. Often, results are normal the second time.
Other results need to be checked more thoroughly. If your doctor suspects abnormal cells or a tumour, the next step is usually colposcopy. This is similar to a standard gynecologic examination, except it's performed with a special microscope that shines a light on your cervix so the doctor can see it better, and dye is put on the cervix to highlight the abnormalities.
If there are lesions in the wall of the cervix that could be a abnormal cells or a tumour, a biopsy (tissue sample) will be needed. There are different types of biopsy procedures. Your doctor will advise which is the most suitable for your specific case. Small cancers can actually be removed entirely with these techniques. Sometimes, following colposcopy, women are told that they had cancer and that it's been removed. In most of these cases, no further treatment is necessary. The same outpatient procedures (i.e., no hospitalization involved) can remove abnormal cells.
At the moment, many provinces recommend Pap smear testing every 1 to 3 years for all women who have ever been sexually active. Specialist groups like the Society of Obstetricians and Gynecologists of Canada and the Gynecologic Oncologists of Canada state that this isn't frequent enough and recommend annual testing. Ask your doctor how often you should be tested in light of your particular circumstances.
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