Cervical Cancer: Who is at high risk and how can it be prevented?

In 2020, the World Health Organization launched a global strategy to eliminate cervical cancer by 2030.

It is the fourth-most common cancer among women, with an estimated 350,000 deaths worldwide in 2022. More than 80,000 of these deaths occurred in sub-Saharan Africa.

Currently, one woman dies every two minutes from this disease, which is caused by the human papillomavirus (HPV). However, cervical cancer is preventable.

The global strategy is built on three pillars: vaccinating 90% of girls against HPV by age 15, ensuring 70% of women are screened by age 45, and providing appropriate management for 90% of women with invasive cancer.

Cervical cancer develops in the cervix, the lower part of the uterus that connects it to the vagina. Nearly 90% of cases result from persistent infection with HPV, a sexually transmitted virus.

Normally, cervical cells divide and grow in a controlled way. However, when a person has sexual contact with an HPV carrier, the outer cervical cells can become infected.

Continued exposure to the virus can cause these cells to grow uncontrollably, leading to pre-cancerous lesions, known as dysplasia.

Though these abnormal cells are not yet cancerous, they have the potential to become so if untreated. This process is gradual and can take years. In many cases, there are no symptoms until the later stages.

Although HPV is a common infection and the primary cause of cervical cancer, not everyone who is infected will develop the disease. Around 90% of HPV infections clear within a year.

About 10% of infections are oncogenic, meaning they can transform normal cells into cancerous ones. HPV infections may progress to cervical cancer or pre-cancer, where some cells develop abnormalities that make them more likely to become cancerous.

There are more than 100 known strains of HPV, with types 16 and 18 considered high risk. These two strains are responsible for over 70% of cervical cancer cases globally.

HPV infection is widespread among sexually active individuals and often occurs without symptoms. Its prevalence is particularly high among young women in the early years of sexual activity.

While most new infections resolve on their own, about 10% can persist, leading to pre-cancerous lesions within five to 10 years. In a minority of cases, these lesions may develop into invasive cancer over several years or even decades, with the highest risk observed between ages 35 and 55.

Factors that increase the risk of HPV exposure include early sexual activity, having multiple sexual partners, and smoking, which weakens the immune system and cellular integrity.

Individuals with compromised immune systems, such as those with HIV or those taking immunosuppressive medications, are also at higher risk of persistent HPV infection and the development of pre-cancerous cells.

What Can Women Do to Avoid Cervical Cancer?

Regular pap smears are crucial for early detection of pre-cancerous cells. In Kenya, health facilities offer pap smear tests, enabling timely intervention to prevent cervical cancer. Women who do not undergo pap smears miss an important opportunity for early detection and intervention.

This has led to the initiative to "vaccinate the child, screen the mother." The most effective defence against cervical cancer is HPV vaccination, which protects against the strains of the virus most likely to cause cervical cancer. Mothers are encouraged to undergo pap smear screening.

Ideally, vaccination should occur before sexual activity begins. It is recommended for preteens (aged 9–15) and can be given up to age 26 for those who have not been vaccinated previously.

Additionally, promoting safe sex practices, limiting sexual partners, and avoiding smoking to reduce HPV exposure risk are essential. Vaccinating both boys and girls is also important in the effort to eliminate cervical cancer.

What Are the Misconceptions About Cervical Cancer?

There are several common myths surrounding cervical cancer. One is that vaccination causes infertility. There is no scientific evidence to support this claim.

Another is the reluctance to discuss sexual and reproductive health openly. There is also a misconception that vaccination is only necessary for women with multiple sexual partners, which is not true.

Historical instances of medical exploitation have fuelled mistrust in healthcare systems, leading to scepticism about vaccination campaigns and screenings.

Embarrassment is a significant barrier to screening, along with a fatalistic attitude toward diagnosis, fear of test results, and the stigma associated with a cervical cancer diagnosis.

Current guidelines recommend two main approaches for managing women who screen positive for cervical pre-cancer: "screen and treat" or "screen, diagnose, and treat."

Both approaches begin with an initial screening test, usually a pap smear or HPV test, followed by treatment.

In the "screen and treat" approach, a positive screening test is followed by immediate treatment, often cryotherapy, which uses extreme cold to remove abnormal cells. Another option is the loop electrosurgical excision procedure (LEEP), which uses a wire loop heated by electric current to remove abnormal cells and tissue from the lower genital tract.

The "screen, diagnose, and treat" approach involves a confirmatory diagnostic test, such as a biopsy, to assess the severity of pre-cancerous lesions before proceeding with treatment. Cryotherapy and LEEP are effective for most women with positive cervical pre-cancer screening results, depending on the specific characteristics of the lesion.

For early-stage cancers, surgery is typically the first step, often a radical hysterectomy, which involves removing the uterus, cervix, part of the vagina, and surrounding tissues.

This is frequently followed by radiotherapy to reduce the risk of recurrence. However, for women with low-risk early-stage disease, the standard of care has shifted toward less radical, fertility-preserving surgeries, allowing the possibility of future pregnancies.

Ultimately, the eradication of cervical cancer requires vaccination, screening, and timely treatment.

Achieving this goal will require collaboration between communities, healthcare providers, international organizations, and governments.

Community education campaigns with culturally sensitive messaging can help dispel myths and emphasize the importance of HPV vaccination for girls as a preventive measure, not as a judgment on sexual behaviour.

Building trust is crucial and can be accomplished by involving trusted voices, such as healthcare providers, community leaders, and women who have been affected by cervical cancer.

Finally, integrating HPV vaccination into existing healthcare initiatives can streamline access, encourage routine childhood vaccinations, and help counter myths about the HPV vaccine.

The author, Dr Solomon Mutua is a Medical Oncologist at The Nairobi West Hospital