Cervical Cancer and HPV
Cancer is a growing health problem in developing countries. More than half the cancer deaths in the world in 1997 occurred in developing countries. Cervical and uterine cancers accounted for more than 50% of all cancers. Twenty per cent of all female deaths from cancer in India in 1990 were from cervical cancer, amounting to an estimated 61,000 deaths from this cause. The number of cervical cancer deaths in women in India is projected to increase to 79,000 by the year 2010.
What is cervical cancer?
The cervix is the neck of the uterus that opens into the vagina. Cervical cancer, also called cervical carcinoma, develops from abnormal cells on the surface of the cervix. Cervical cancer is usually preceded by dysplasia, precancerous changes in the cells on the surface of the cervix. These abnormal cells can progress to invasive cancer. Once the cancer appears it can progress through four stages. The stages are defined by the extent of spread of the cancer. The more the cancer has spread, the more extensive the treatment is likely to be.
How does it occur?
Infection with oncogenic human papilloma virus (HPV) is the major risk factor in the etiology of cervical cancer. Upto 99.8% of cervical cancer are associated with HPV. Approximately 30 types of HPV cause infection of genital mucosal sites, and these genital types are generally characterized as " high-risk types (e.g., HPV 16,18,31,33,35,39,45,51,52) which are associated very strongly with carcinoma cervix, and "low-risk" types (e.g., HPV 6,11,42,43,44) which are associated with genital warts and are unlikely to be associated with cervical carcinoma.
You are at greater risk for cervical cancer if:
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You or your sexual partner has or had a genital wart virus infection |
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You have had many sexual partners or began sexual activity before age 18. |
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You do not use condoms with new partners. |
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You had previous genital or vaginal cancer. |
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Your sexual partner's previous partner had cervical cancer or abnormal cervical cells. |
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Your sexual partner's previous partner had cervical cancer or abnormal cervical cells. |
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You smoke cigarettes. |
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Your immune defenses are low, such as in the case of people with transplants, people taking immunosuppressive drugs, or people with AIDS. |
What are the symptoms?
Early cervical cancer usually causes no symptoms. The cancer is usually detected by a Pap smear and pelvic exam (see below). This is why women should start having Pap smears and pelvic exams as soon as they become sexually active. Healthy young women who have never been sexually active should have their first annual pelvic exam by age 18.
Eventually, a woman who has cervical cancer will notice abnormal vaginal bleeding or a bloodstained discharge at unexpected times, such as between menstrual periods, after intercourse, or after menopause. Abnormal vaginal discharge may be cloudy or bloody or may contain mucus with a bad odor. Advanced stages of the cancer may cause pain.
How is it diagnosed?
Your doctor will take a Pap smear. During this test, your provider will use a small spatula and brush to gently scrape cells from the cervix. The cells are spread across a glass slide. The slide is sent to a lab where the cells are examined.
Your Pap smear may show cells that are:
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Normal |
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Mildly abnormal |
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Precancerous |
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Cancerous |
Mild abnormalities will most likely return to normal with minimal or no treatment. However, you should have follow-up Pap smears every few months as recommended by your doctor to make sure the cells have returned to normal.
Drawbacks of PAP smear:
The PAP smear does not detect the cause of all infections or diseases but reports mainly cellular abnormalities. The cytology is complex, depends upon obsever's interpretative skills. It is pone to sampling errors, which leads to false negative or inconclusive results.
If the Pap smear reveals more significant abnormalities, your doctor will want to look at the cervix with a colposcope.
A colposcope is a special type of microscope that allows your doctor to examine the vagina and cervix. During the examination, a sample of the abnormal tissue may be taken by cutting off a tiny piece of the cervix (a biopsy) or by taking scrapings from the lining of the cervical canal (endocervical curettage). The samples are sent to the lab to test for cancer cells.
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Limitations of Colposcopy: |
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Colposcopy has a low specificity (less than 50%) which leads to over treatment. There is wide range of inter and intra observe variation. There is also lack of reproducibility and it requires extensive training & experience. |
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HPV DNA Testing by Hybrid Capture II system |
This is done on cervical brushings taken by your doctor. It is a nucleic acid (DNA) hybridization based linear signal amplificaion technology, to detect viral DNA. It also can differentiate high-risk carcinogenic HPV from low-risk types, which aids in the correct management of the patients.
Presently this test is recommended by EUROGIN (European Research Organization of Genital Infection and Neoplasia) on patients of abnormal PAP smear because: HPV testing is objective and highly reproducible. The detection of high-risk HPV in 99.8% of cervical sample establishes the rationale for utilization of high-risk HPV testing in screening program. In fact this test hitherto available only in western countries has now been available recently by some advanced diagnostic centers in India.
How is it treated?
The earlier cervical cancer is diagnosed and treated, the greater the chances are that your ability to have children can be preserved.
The early precancerous changes can usually be treated easily with:
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Laser surgery |
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Cryosurgery (freezing treatments) |
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Electrocautery (burning with a wire) |
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Surgery to remove precancerous tissue |
Discuss the advantages and disadvantages of these treatments with your doctor
Cancer on the surface of the cervix is called cancer in situ of the cervix. Possible treatments for this type of cervical cancer are:
Cone biopsy of the cervix, which is removal of a cone- shaped piece of the cervix with a surgical knife, laser, or wire loop Hysterectomy, which is removal of the uterus.
Treatment of invasive cervical cancer depends on the extent of the cancer, your age and general health, and the risk that it will spread to other parts of the body. If the invasive cancer is small and involves only the cervix or uterus, your health care provider may recommend removing the uterus and cervix, upper vagina, and some surrounding tissue in the pelvis. The ovaries are usually removed also, but on rare occasions they are not removed so your normal hormone function may be preserved. (If your ovaries are removed, you may take estrogen after the surgery.) For more advanced cervical cancer, you may have combined radiation and chemotherapy.
