The exact cause of cervical cancer is not fully understood, but it is believed to be caused by certain types of human papillomavirus (HPV), which are sexually transmitted infections.
There are over 100 different types of HPV, but only a few of them are known to cause cervical cancer. These types of HPV, called high-risk HPV, can infect the cervical cells and cause them to become abnormal. In most cases, the body’s immune system is able to clear the infection and the abnormal cells return to normal. However, in some cases, the infection persists and the abnormal cells continue to divide and grow, eventually forming a cancerous tumor.
Other factors that can increase a woman’s risk of developing cervical cancer include:
- Many sexual partners. The greater your number of sexual partners — and the greater your partner’s number of sexual partners — the greater your chance of acquiring HPV.
- Early sexual activity. Having sex at an early age increases your risk of HPV.
- Other sexually transmitted infections (STIs). Having other STIs — such as chlamydia, gonorrhea, syphilis and HIV/AIDS — increases your risk of HPV.
- A weakened immune system. You may be more likely to develop cervical cancer if your immune system is weakened by another health condition and you have HPV.
- Smoking. Smoking is associated with squamous cell cervical cancer.
- Exposure to miscarriage prevention drug. If your mother took a drug called diethylstilbestrol (DES) while pregnant in the 1950s, you may have an increased risk of a certain type of cervical cancer called clear cell adenocarcinoma.
- Long-term use of oral contraceptives. Oral contraceptives, also known as birth control pills, contain hormones that can change the way the cervix functions and make it more susceptible to HPV infections. Studies have shown that women who use oral contraceptives for a long period of time have a slightly increased risk of developing cervical cancer, particularly if they use the pills for more than five years. However, it is worth noting that the benefits of oral contraceptives, such as reduced risk of ovarian and endometrial cancer, may outweigh the risks.
- Having multiple full-term pregnancies. Women who have had multiple full-term pregnancies are at a slightly increased risk of developing cervical cancer. This is thought to be because the cervix undergoes changes during pregnancy that can make it more susceptible to HPV infections. Additionally, women who have had many pregnancies have more exposure to HPV over time.
- Having a family history of cervical cancer. Women who have a family history of cervical cancer, particularly a first-degree relative such as a mother or sister, may be at an increased risk of developing cervical cancer themselves. This may be due to genetic factors that make some women more susceptible to HPV infections or to cervical cell changes.
It is important to have regular cervical cancer screenings, such as Pap tests or HPV tests, to detect and treat precancerous changes in the cervix before they become cancerous. Vaccines that protect against certain types of HPV, such as HPV-16 and HPV-18, are also available and can help reduce the risk of cervical cancer.