ABC Health & Wellbeing

Fact File

Cervical cancer

by Markye Steffens

Cervical cancer is the second most common cancer in women worldwide, and the 13th most common cancer in women in Australia. But regular Pap smears and a new vaccine can prevent many cases.

Published 29/11/2005

[Image source: iStockphoto]

• Background
• Causes
• Symptoms
• Diagnosis
• Staging & Treatment
• Prognosis
• Screening, Prevention & Vaccine
• More info

Background

Cervical cancer is one of the good news cancer stories in Australia. Since the introduction of routine Pap smears and a national screening program, the number of deaths from cervical cancer annually has more than halved, demoting cervical cancer to the 13th most common cancer in women in Australia. At the moment, one in every 183 Australian women will develop cervical cancer by the age of 75.

Where is the cervix? It's the lower part of the uterus that extends into the vagina, often called the neck of the womb. The cervix connects the uterus to the vagina, and is important for producing moistness to lubricate the vagina and holding the baby in the uterus during pregnancy.

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Causes

Cervical cancer is one of the few cancers where we know what causes it, and that's through infection with a sexually transmitted virus called Human Papilloma Virus, or HPV.

Studies have shown that up to 80% of adults will at some point in their lives be infected with the HPV virus. So why do some women get cervical cancer and others don't?

Part of it comes down to which type of Papilloma Virus you're infected with. There are over one hundred types, about 40 of which infect the genital tract. Some of these cause genital warts, and around 15 types have the ability to cause cancer, including the main types HPV-16 and HPV-18.

Even if you do become infected with a cancer-causing type of Papilloma Virus, you won't necessarily develop cervical cancer. More often than not, the infection disappears after losing the battle with your immune system.

What's responsible for whether your immune system can beat this virus or not? Scientists aren't sure, but there are some known risk factors that may influence whether you go on to develop cervical cancer or not.

Your age Cervical cancer is most common in women over the age of 50. Precancerous changes on the cervix occur most commonly between the ages of 30 and 50.

Smoking Some studies suggest that smoking increases the risk of cervical cancer fourfold. Why? It may be because smoking introduces chemicals into the body that damage the cells of the cervix and make cancer more likely to develop.

DES DES (diethylstilboestrol) is a hormonal drug that was prescribed up until the early '70s to prevent miscarriage. Daughters of women who took DES when pregnant with them may have an increased chance of developing cervical cancer.

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Symptoms

One of the problems with cervical cancer is that early changes (pre-cancers and early cancers) rarely cause symptoms, which is why it's important to go for regular Pap smears (but more on that later.)

Symptoms often develop only when the cancer becomes invasive and invades nearby tissue. When this happens the most common symptom is abnormal vaginal bleeding, or bleeding between periods. This can include blood spots or light bleeding.

Other symptoms include:

• bleeding after intercourse;
• pain during intercourse;
• unusual vaginal discharge;
• vaginal bleeding after menopause;
• excessive tiredness;
• leg pain or swelling; and
• low back pain.

There are other conditions which can cause these symptoms, but you should go get checked by a doctor regardless. If you ignore symptoms you run the risk of the cancer progressing to a more advanced stage which may impact on the effectiveness of any treatment you might need.

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Diagnosis

Unlike some cancers, cervical cancer is slow growing and can take a long time to develop; the average is around ten years.

Early changes, which may or may not develop into cancer, appear as abnormal cells on the surface of the cervix and can be picked up by a Pap smear. If these pre-cancerous abnormalities are considered to be severe enough, they can be treated before they develop into cancer.

There are two types of cervical cancer proper, named after the type of cell they initially form in: squamous cell carcinoma, which is the most common type and forms in the cells on the surface of the cervix, and adenocarcinoma, which is less common and forms in the mucus-producing gland cells in the cervical canal.

Cervical cancer is also classed as microinvasive, which means the cancer has only superficially invaded the cervix and has not spread to other organs, or invasive, which means the cancer has spread deeper into the cervix and possibly into the vagina, surrounding lymph nodes or other tissues near the pelvic area.

If you're experiencing any of the symptoms of cervical cancer, your doctor will perform a series of tests to determine whether you have pre-cancerous or cancerous cells on your cervix, and the severity of the abnormality.

The first such test is a colposcopy, where your doctor takes a magnified look at the surface of your cervix with what looks like a pair of binoculars on a stand. If abnormal areas are found, your doctor may take a small piece of tissue to send to a pathologist to look at under a microscope. A biopsy is the only way to tell for sure whether the abnormal cells are pre-cancerous or cancerous.

If abnormal cells are found in your biopsy, the next step is to have a cone biopsy. This is usually done under general anaesthetic and involves removing a larger, cone shaped piece of tissue from your cervix. This may be done to either remove the abnormal cells from the cervix completely, or to find out whether the cancer is invasive and has spread deeper into the cervix.

There are other tests your doctor might do to see whether the cancer has spread to other areas in the pelvic area. These include an extensive physical examination, magnetic resonance imaging, and a computerised tomography (CT) scan.

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Staging and treatment

During the process of diagnosis, your doctor will find out how far the cancer has spread, and this will determine your treatment plan. Stage 0 means the cancer is only in the cells of the surface of the cervix, whereas Stage I means the cancer cells have invaded deeper into the cervix. Stages II through IV indicate the cancer has spread beyond the cervix to other tissues in the pelvic area or beyond.

Treatment for cervical cancer includes surgery, radiotherapy, and chemotherapy, and the best treatment depends on the extent of the disease at the time of diagnosis.

Most women will have some form of surgery to remove abnormal cells from their cervix. This can either be a cone biopsy, which can remove very early cervical cancers, or a hysterectomy, in which the uterus is removed. In a total hysterectomy the uterus and the cervix are removed, while in a radical hysterectomy the tissue adjacent to the cervix, some lymph nodes, the top part of the vagina and supporting ligaments are removed as well as the uterus and cervix.

For some women the treatment ends there, but what if you need more than surgery? Your doctor may recommend chemotherapy and/or radiotherapy if the cancer is more advanced and difficult to cure by surgery alone. Both treatments have a number of side effects which include tiredness, loss of appetite, and feeling nauseous.

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Prognosis

The earlier you catch cervical cancer, the better the prognosis and most women with early cervical cancer will be cured. For women with more advanced cervical cancer, there is still the possibility of a cure. Surgery is often successful in removing the cancer, and a combination of treatments can keep any remaining cancer under control for long periods of time.

If there is no invasive cancer present, that is, the abnormal cells are confined to the surface of the cervix, then the prognosis is usually excellent with complete cure.

If there is invasive cancer present, then although the situation is potentially, the prognosis depends on the extent of the disease. Studies have shown that the five-year relative survival rate for the earliest stages of invasive cervical cancer is 92%. That means that 92 out of every 100 patients with this stage of cancer will live at least five years after their cancer is diagnosed. If you combine all the stages together, the five-year survival rate is about 73%.

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Screening, prevention and a vaccine

Screening for cervical cancer is the best way to prevent it, and statistics show that 90% of cervical cancers are preventable for women who have a Pap smear every two years. Cervical cancer deaths are higher in countries were women do not have access to routine Pap smears, and in developing countries cervical cancer is the second-most common cancer in women. In Australia we're lucky; we have a program called the National Cervical Screening Program which works to encourage all Australian women to have regular Pap smears.

During a Pap smear, your doctor will take scraping of cells from the surface of the cervix, which are then sent to a pathologist for analysis. Having regular Pap smears means that abnormal cells that could become cancerous will almost definitely be found.

An effective vaccine is now available that prevents persistent infection in women who have not been exposed to HPV, such as girls who are not yet sexually active.

Called Gardasil, the vaccine has been shown to be 100 per cent effective against HPV types 6, 11, 16, and 18, which are responsible for 70 per cent of cervical cancer cases and 90 per cent of genital warts in women.

The vaccine involves three injections over a three-month period.

As of the beginning of 2007 the vaccine will be free for women aged between 18 to 26, available through their GP. From April 2007, it will also be given to 12-13 year-old girls at school as part of the National Immunisation Program, and there'll also be a government-funded catch up program for 13-18 year-old girls at school.

Women who have been vaccinated will still have to have Pap smears, to guard against developing cancer and abnormalities from the other types of HPV not prevented by the vaccine.

Reviewed by Gerry Wain, Director of Gynaecological Oncology at Westmead Hospital, Sydney, and Director, NSW Cervical Screening Program.

Updated 16/01/2007