So far, it is not fully understood what causes cells to become abnormal and to grow without control. Some factors have been observed to increase the risk of developing cancer of the cervix.
HPV: The most important risk factor is the infection of the cervix with HPV. HPV is one of the most common sexually transmitted infections (STIs). It is estimated that 75% of individuals who are sexually active will have at least one HPV infection in their lifetime. While some types of HPV cause genital warts, other strains of the virus can infect the cervix and then cause abnormal changes within the cells that may slowly progress to cancer. It is important to note that most women diagnosed with cervical cancer had a previous HPV infection; however, not all women with an HPV infection will develop this type of cancer.
Sexual activity: Becoming sexually active at an early age is linked to a higher risk of cervical cancer. Also, certain sexual behaviours (such as having multiple sex partners and partners who have multiple partners) can increase a woman's likelihood of becoming infected with HPV, thereby increasing the risk of cervical cancer.
Smoking: People who smoke are at higher risk of cervical cancer, as well as other cancers. Both tobacco smoking and exposure to secondhand smoke (environmental tobacco smoke) have been associated with the development of cervical cancer. In fact, the risk increases with the length of time a woman smokes and the number of cigarettes consumed per day.
Weakened immune system: Our immune system helps our body fight infections. Therefore, medications and diseases that diminish the immune system can increase a woman's risk of HPV infections, thereby increasing the risk of cervical cancer. Examples of medications that suppress the immune systems are corticosteroids (used over a long period of time) and chemotherapy drugs. Women infected with the human immunodeficiency virus (HIV) have an increased risk of developing precancerous cervical changes with an HPV infection.
Diethylstilbestrol (DES): DES was a form of estrogen used during pregnancy between 1940 and 1971. Some studies have suggested that DES-exposed daughters may be at increased risk of developing precancerous cervical cancer and squamous cell carcinoma of the cervix.
Age: Most cases of cervical cancer tend to occur in women younger than 50 years of age.
Socioeconomic status: Women with lower incomes are at higher risk of developing cervical cancer because they are less likely to receive regular Pap test screenings.
Oral contraceptives: Using birth control pills for a long time (for example, more than 10 years) increases the risk of cervical cancer. This risk decreases once the pill is stopped.
Multiple births: Women who have given birth multiple times are at increased risk of cervical cancer, with the risk increasing as the number of births increase.
Other risk factors: Other possible factors have been associated with increased risk of cervical cancer. However, there is currently not enough evidence to consider them as main risk factors. These factors include having a family history of cervical cancer or a history of sexually transmitted infections.