What causes cervical cancer?

Cervical cancer is a serious health concern that affects thousands of women worldwide and often has no symptoms in its early stages. Understanding the underlying causes of this disease is important for effective prevention and early detection. In this article, we will look into the various risk factors and potential triggers that contribute to the development of cervical cancer, separating fact from fiction to empower you with the knowledge needed to safeguard your health.

The Human Papillomavirus (HPV) Infection

At the core of cervical cancer is the human papillomavirus (HPV) infection. This group of over 150 related viruses is the main reason behind the vast majority of cervical cancer cases. HPV can infect the cells of the cervix, and certain high-risk strains of the virus can alter the DNA of these cells, causing them to multiply uncontrollably and form tumours. While HPV is a widespread infection, affecting over 85% of the general population, not everyone with the virus will develop cervical cancer.

Symptoms of cervical cancer

As cervical cancer advances, some individuals may begin to experience subtle changes that could signal the presence of the disease. These can include:

• Unusual vaginal bleeding, such as bleeding after intercourse, between menstrual periods, or after menopause
• Changes in vaginal discharge, which may become watery, bloody, or have an unpleasant odour
• Discomfort or pain during sexual intercourse

Understanding HPV transmission

HPV is primarily transmitted through skin-to-skin contact, often during sexual activity. The virus can be spread through vaginal, anal, or oral sex, as well as by sharing sex toys. It’s important to note that HPV can be contracted even with a single sexual encounter, highlighting the importance of practising safe sex and maintaining a healthy sexual history.

High-Risk HPV types

While there are many types of HPV, there are high-risk types due to their strong association with cervical cancer. These high-risk HPV types, such as HPV 16 and 18, can integrate their genetic material into the host cell’s DNA, disrupting normal cellular processes and leading to the development of precancerous lesions and, ultimately cervical cancer.

Sexual history and cervical cancer risk

An individual’s sexual history can also play a significant role in their risk of developing cervical cancer. Factors such as early age of first sexual intercourse, multiple sexual partners, and having a partner with a history of multiple partners can all contribute to an increased likelihood of HPV infection and, consequently, cervical cancer.

Early sexual activity

Women who become sexually active at a young age, particularly before the age of 18, have a higher risk of developing cervical cancer later in life. This is likely due to the increased exposure to HPV and the delicateness of the cervix during adolescence when the cells lining the cervix are still undergoing maturation.

Multiple sexual partners

The more sexual partners an individual has, the greater their chances of being exposed to HPV and contracting the virus. This is because each new partner brings the potential for a new HPV infection, increasing the overall risk.

Weakened immune system and cervical cancer

The strength of an individual’s immune system plays a crucial role in the development of cervical cancer. A weakened immune system, whether due to HIV/AIDS, organ transplantation, or certain autoimmune disorders, can impair the body’s ability to effectively fight off HPV infections and prevent the progression of precancerous lesions to invasive cancer.

HIV and cervical cancer

HIV, the virus that causes AIDS, is particularly concerning when it comes to cervical cancer risk. HIV weakens the immune system, making it more difficult for the body to clear HPV infections and control the growth of precancerous abnormal cells. Women with HIV have a significantly higher risk of developing cervical cancer compared to those with a healthy immune system.

Autoimmune disorders and cervical cancer

Individuals with autoimmune disorders, such as lupus or rheumatoid arthritis, often take immunosuppressive medications to manage their condition. These drugs, while necessary for managing the autoimmune disease, can also compromise the body’s ability to fight off HPV infections and prevent the development of cervical cancer.

Smoking and cervical cancer

Smoking is another significant risk factor for cervical cancer. Tobacco use has been shown to increase the likelihood of developing the disease, as well as the progression of precancerous lesions to invasive cancer. The harmful chemicals found in cigarette smoke are believed to damage the DNA of cervical cells, making them more susceptible to HPV.

The link between smoking and immune system impairment

In addition to the direct cellular damage caused by tobacco, smoking also weakens the immune system, reducing the body’s ability to effectively clear HPV infections and prevent the development of cervical cancer. This dual impact of smoking on both the cervical cells and the immune system further heightens the risk.

Diethylstilbestrol (DES) exposure and cervical cancer

Another risk factor for cervical cancer that cannot be changed is exposure to the synthetic hormone diethylstilbestrol (DES) during pregnancy. DES was once prescribed to some pregnant women in the mid-20th century to prevent miscarriage, but it was later found to increase the risk of certain cancers, including clear-cell adenocarcinoma of the vagina and cancer of the cervix in the daughters of women who took the drug.

The lasting impact of DES exposure

While the use of DES during pregnancy was discontinued in 1971, the impact of this exposure can still be seen today. Women whose mothers took DES while pregnant with them have a higher risk of developing rare forms of vaginal and cervical cancer, even decades later. This highlights the importance of understanding one’s medical history and discussing any potential DES exposure with healthcare providers.

Family history and cervical cancer

Cervical cancer may also have a familial component, with some research suggesting that the disease can run in certain families. While the exact mechanisms are not fully understood, it is believed that genetic factors may play a role in an individual’s susceptibility to HPV infection and the development of cervical cancer.

Cervical cancer screening

HPV vaccination does not protect against all types of HPV that cause cervical cancer, so getting screened regularly is important.

Screening tests include cytology and HPV tests (also known as Pap tests or Pap smears). These tests can find high-risk HPV infections and abnormal cell changes as well as precancers. For these tests to be effective, people need to have regular screening and follow-up of abnormal test results.

Dietary factors and cervical cancer

While the primary risk factors for cervical cancer are related to HPV infection and sexual history, some studies have also suggested a potential link between certain dietary factors and the development of this disease.

The protective role of fruits and vegetables

Research indicates that a diet rich in fruits and vegetables may help reduce the risk of cervical cancer. The antioxidants and other beneficial compounds found in these foods are believed to support the immune system and potentially inhibit the growth of precancerous cells.

The importance of a balanced diet

Maintaining a balanced and nutritious diet, with a focus on incorporating a variety of fruits, vegetables, and other nutrient-dense foods, may play a role in supporting overall health and reducing the risk of cervical cancer. However, it’s important to note that dietary factors alone are not a substitute for regular cervical cancer screening tests and the management of other risk factors.

Intrauterine Device (IUD) use and cervical cancer

Interestingly, some research suggests that the use of an intrauterine device (IUD) may be associated with a lower risk of cervical cancer. While the exact mechanisms are not fully understood, it is thought that the presence of an IUD may somehow interfere with the development or progression of precancerous lesions.

The potential protective effect of IUDs

Studies have found that women who have ever used an IUD, even for a short period, may have a reduced risk of cervical cancer compared to those who have never used an IUD. However, it is important to note that IUDs do carry their own set of risks and should be discussed with a healthcare provider before considering their use.

Chlamydia infection and cervical cancer

Certain sexually transmitted infections, such as chlamydia, have also been linked to an increased risk of cervical cancer. While the exact relationship is not entirely clear, some research suggests that the presence of chlamydia infection may help HPV thrive and persist in the cervix, potentially contributing to the development of precancerous and cancerous lesions.

The potential role of chlamydia in HPV persistence

Chlamydia is a common bacterial infection that can be transmitted through sexual contact. Some studies have found that women with evidence of past or current chlamydia infection may have a higher risk of cervical cancer. The theory is that the presence of chlamydia may create an environment that is more favourable for HPV to establish and maintain a persistent infection, ultimately increasing the chances of cervical cancer development.

Oral contraceptive use and cervical cancer

Another potential risk factor for cervical cancer is the long-term use of oral contraceptives, commonly known as birth control pills. While the exact mechanisms are not fully understood, some research has suggested a link between prolonged oral contraceptive use and an increased risk of cervical cancer.

The importance of balancing risks and benefits

It is important to note that the increased risk associated with oral contraceptive use is relatively small, and the benefits of these medications, such as pregnancy prevention and menstrual regulation, may outweigh the potential risks for many women. Nonetheless, individuals must discuss the potential risks and benefits of oral contraceptive use with their healthcare providers, especially in the context of their overall cervical cancer risk profile.

Pregnancy and cervical cancer

Interestingly, the number of full-term pregnancies a woman has had may also influence her risk of developing cervical cancer. Women who have had three or more full-term pregnancies appear to have a higher risk of cervical cancer compared to those with fewer or no full-term pregnancies.

The potential factors at play

The reasons behind this association are not entirely clear, but it is thought that the hormonal changes and increased exposure to HPV during pregnancy may play a role. Additionally, the physical stress and strain of multiple pregnancies may potentially weaken the immune system, making it more difficult for the body to effectively clear HPV infections and prevent the development of cervical cancer.

Conclusion

Cervical cancer is a complex disease with many causes. While HPV infection remains the primary cause, a range of other risk factors, including sexual history, immune system status, smoking, and even dietary and reproductive factors, can all contribute to an individual’s likelihood of developing this malignancy.

By understanding the various causes and risk factors associated with cervical cancer, individuals can make informed decisions about their healthcare, prioritise regular screening, and take proactive steps to reduce their risk.

Sources

• Cervical cancer – Symptoms and causes – Mayo Clinic
• Causes of cervical cancer – NHS
• Cervical Cancer Risk Factors –  Risk Factors for Cervical Cancer – American Cancer Society