Cervical cancer
What is the cervix?
The cervix is the extension of the uterus into the top part of the vagina. A small passage through the middle of the cervix leads into the cavity of the uterus. In a normal situation, squamous epithelium (a thin layer of ‘scaly' cells that covers the internal and external surfaces of the body, including body cavities, ducts and vessels) lines the cervix from this opening outwards. The inside of the cervix normally has a more fragile epithelium lining which under normal circumstances is not exposed to the environment.
Certain hormonal changes such as pregnancy and the oral contraceptive pill may cause the inner lining from inside the cervix to move temporarily outwards to be visible on the outside of the cervix. This is sometimes referred to as erosion by doctors, and may cause bleeding during the first trimester.
What is cervical cancer?
Cervical cancer usually arises from the outside cell layer of the cervix and is therefore of the squamous cell cancer type.
Reasons for the condition developing
The number one risk factor for cervical cancer is infection with HPV (genital warts virus). Any factor which increases a woman's risk of contracting HPV will increase the risk of cervical cancer.
Who is at risk?
Cervical cancer is common and occurs during childbearing years. Geographically, cervical cancer is found worldwide but it is especially common in women in Africa and the western world. It is also becoming more common in HIV-infected women and those who have certain subtypes of the genital warts virus - human papillomavirus (HPV).
Women are at increased risk for developing HPV if they:
- contracted sexually transmitted infections (STI)
- have intercourse without barrier contraceptives
- have multiple sexual partners
- have sex with a partner who has penile warts.
Smoking cigarettes doubles a woman's risk of getting cervical cancer, but is considered a ‘cumulative' (increasing) risk.
Further development of the cancer
This type of cervical cancer spreads by lymphatic spread to local and then more distant lymph nodes. Blood-borne cancer cells can spread to the lungs or to bones.
Symptoms of cervical cancer
It must be remembered that pre-cancerous lesions and early onset of cancer, called cervical intraepithelial lesions (pre-cancerous) and invasive carcinoma may have no symptoms. However, symptoms suggestive of cervical cancer are:
- abnormal vaginal discharge
- abnormal vaginal bleeding, which may be bleeding after sexual intercourse, inter-menstrual bleeding or bleeding after menopause. This type of bleeding may be no more than a spot of blood.
Diagnosis of cervical cancer
A pap smear is a screening test for cervical cancer. The pap smear is a method used to examine cells from the cervix. Your doctor will do a pelvic examination and use a brush or spatula to take cells from the cervix and transfer them onto a glass slide or add them to a preservative fluid (liquid-based cytology).
Cervical cancer is diagnosed by pap smear and by biopsy (taking tissue sample) from the affected area and then detecting the cancer cells under the microscope by adding a colouring agent. A cone biopsy (a core of tissue is removed from the cervix) is also often done as a confirmation of the cancer diagnosis. It detects the disease in its early stages, which has helped reduce the number of deaths relating to cervical cancer. If the patient is diagnosed with cervical cancer, other tests such as X-rays, bone scans and blood tests will be performed to evaluate whether the disease has spread to other organs.
Staging: determining how far the cancer has developed
Typically, cervical cancers develop slowly over a period of several years.
Once a diagnosis of cervical cancer is made, the next step in the evaluation is to assess the ‘stage' of the cancer. Staging is a system that describes the size of the cancer and any signs of spread. For all cancers, including cervical cancer, treatment and prognosis depend on the tumour stage.
In cervical cancers, the stage is based on the size of the cancer and the extent of its spread into the tissues surrounding the cervix, whether the vagina, side walls of the pelvis, or local lymph nodes are involved, and whether the cancer has spread to other organs (metastasized).
Treatment of cervical cancer
Early detection of precancerous lesions allows treatment to take place before cancer has actually developed. The treatment may vary from only regular pap smears, excision of abnormal cells with laser surgery or removal of uterus and cervix. Cervical cancer is usually preventable with regular pap smear screening for cervical cancer. This allows the very earlier non-cancerous stages of the condition (called dysplasia) to be treated in time.
Treatment of more severe cervical cancer
For more severe forms of pre-cancer states, which are closer to becoming frank cancer or for carcinoma in-situ, the treating doctor will advise on whether a local procedure such as removal of part of the cervix (cone biopsy) will be best or whether more extensive surgery such as hysterectomy should be carried out. A lot of this will depend on age and childbearing status.
Treatment differs from patient to patient and will be personalised for the patient by the treating doctors. For more invasive cervical cancer, successful treatment is radiotherapy and/or surgery to remove the cervix, uterus, tubes and ovaries together with a small segment of vagina. There are a number of ways to administer radiotherapy: externally (external beam radiation) to placing radioactive implants into the vagina which gives local radiotherapy, to the area where it is needed most.
In addition to surgery and laser as well as other local treatments, patients with more advanced disease need radiotherapy and chemotherapy. Many combinations of chemotherapy are used and some of these contain drugs such as cisplatin, ifosfamide, mitomycin, 5-fluorouracil and others.
What happens after treatment?
After treatment, monitoring of outcomes may be by regular visualisation and testing of the cervix through colposcopy (instrument with microscope which enables your doctor to magnify the cervix and look for abnormal areas) to check on the state of the existing cervical cells in advanced cervical cancer.
X-ray techniques are used in measuring the response of distant cancer (metastases) to treatment. General follow-up procedures may include the following:
- Physical examination every three months for the first year. Your follow-up visit interval will become longer the longer you are disease-free, every four months for one year, every six months for three years, and then annually. This usually involves a physical examination and a pap smear (cervical cytology).
- Annual chest X-ray; there is very little data to support the benefit of annual chest X-rays and many doctors do not recommend these.
- Other radiographic studies are performed if needed.
The cervical cancer symptoms that may require attention are pelvic pain from locally advanced disease. Diarrhoea may be a complication of treatment for this condition. Other body pains from bone metastases may cause problems, as may pain from liver or lung metastases.
References
eMedicine: cervical cancer
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