While medicine cannot point a single finger at the cause of cervical cancer, it does point at the link between cervical cancer and the human papilloma virus (HPV) and risk factors which increase chances of developing cervical cancer. HPV is responsible for over 90 per cent of all cervical cancer.
HPV in combination with nine other identified risk factors substantially increases the risk for cervical cancer. The remaining nine risk factors are normally found in combination in the ten per cent of cases where HPV is not a factor.
Women with none of the risk factors rarely contract cervical cancer. Women who have had HPV have an increased risk of developing cervical cancer.
What is cervical cancer?
Two types of cervical cancer are squamous cell cancer and adenocarcinoma. When both types of cancer are present in the cervix, it is called mixed carcinoma. 80 per cent of all cervical cancer is squamous cell cancer.
Cervical cancer is a slow-growing cancer which begins with changes in the cervical cells. While some pre-cancer cells (changed cervical cells) will disappear without treatment, more will continue to change and invade deeper into the cervix, developing into invasive cervical cancer.
Yearly, 11,000 American women are diagnosed with invasive cervical cancer. Of those, nearly 4,000 will die.
What are the risk factors?
1. Human papilloma virus (HPV)
Over 100 variants of HPV exists. Infections of two specific types of HPV (16 and 18) cause 70 per cent of cases of cervical cancer.
The majority of HPV infections go away on their own and do not cause cervical cancer. Frequent or persistent (lasting years) HPV infections increase the risk of developing cervical cancer.
HPV is transmitted through sex. Condom use lowers the risk of infection, but cannot guarantee protection.
Vaccinations against HPV 16 and 18 and the genital wart-causing HPV 6 and 11 are available and recommended for girls 12-18. These vaccines do not protect against all forms of HPV.
If a woman is sexually active, the only proven form of HPV infection prevention is a mutually monogamous sexual relationship with a non-infected partner.
2. Sexually transmitted diseases (STD)
STD increase the risk of cervical cancer, especially when in concert with HPV. Women with both genital herpes and HPV had double the risk for developing cervical cancer.
Chlamydia and HPV infections increase the risk for cervical cancer by 80 per cent.
3. Oral contraceptives (OC)
Since cancer depends on naturally occurring hormones, the use of oral contraceptives (birth control pills) influence the risk of developing cervical and breast cancers, while decreasing the risk of ovarian and uterine cancers.
International Agency for Research on Cancer (IARC) studied women with cervical cancer and found an increase risk in women even after discontinuing use of OC. IARC reports women with HPV infections who used OC for five years are four times more likely to develop cervical cancer. The study also showed women with HPV infections who used OC before age 20 or within the last five years also had higher risk.
Further studies show ten years after discontinuing OC use, cervical cancer risk returns to pre-use levels.
4. Sexual history
Having sex early (before age 16), with a man who has had multiple (more than 3) partners and/or with multiple partners increases the risk of cervical cancer by increasing exposure to HPV infection.
5. Smoking
Smoking cigarettes increases the risk of HPV abnormalities developing into cervical cancer.
6. Weakened immune system
Women with human immunodeficiency virus (HIV), and the resulting acquired immune deficiency syndrome (AIDS), or who take immune suppressing drugs are at higher risk of developing cervical cancer. Their bodies cannot fight HPV and STD infections.
7. Diesthylstilbestrol (DES) exposure
Women born or pregnant between 1938 and 1971 may have been exposed to DES, which has been linked to a rare form of cervical cancer. While no tests exist to test for DES exposure, self-assessment can help women and men determine whether they have been exposed.
8. Failing to take pap tests
In a pap, test a doctor scrapes cells from the cervix to be examined under a microscope. Menstruating and menopausal women should be screen for cervical cancer with a pap test once per year. Post menopausal women should be tested every three years.
Since the pap test can detect pre-cancer cells, women who are regularly tested often have their pre-cancer treated before it develops into cervical cancer.
9. Multiple pregnancies
Since pregnancy changes the cervix over time, studies show women who have had multiple children are at higher risk for cervical cancer. Women who have delivered more than five children are at even higher risk.
10. Genetics
Familial history plays a role in cancers. While most cervical cancer is caused by behavioral factors, mutations of certain genes can be responsible for an increase risk in developing cervical cancer. No single gene mutation has been identified as a cause for cervical cancer.