Cancer screening, and HPV vaccination – key to prevention
Dr Lata Kini, Lead Clinical Pathologist, CORE Diagnostics
Ask any 10 women in India whether they have ever undergone cervical cancer screening and about 9 of them would have not. Despite the readily available and convenient screening modalities in the form of Pap smear test or liquid based cytology that can help prevent cervical cancer or detect it in its asymptomatic stage, most women in India do not undergo regular cervical screening. As a result, an overwhelming number are diagnosed with the disease in an advanced or invasive stage, by when it becomes difficult to treat.
While cervical cancer is one of the deadliest cancers in women worldwide, it is also one of the easiest to prevent. However, lack of awareness about the disease, its causes, preventive measures as well as the need for screening makes it the leading cause of mortality due to cancer in women across the world. According to World Health Organization, more than 270,000 deaths are attributed to cervical cancer, with 85% occurring in developing countries like India. An estimated 132,000 new cases are diagnosed annually in India and 74,000 deaths are reported. India, therefore accounts for almost one third of the global cervical cancer deaths.
On a brighter note, most of these deaths can be prevented if cervical cancer screening becomes a norm in India, along with vaccination for sexually transmitted HPV virus that is the leading cause of cervical cancer.
Early cervical cancer has no symptoms
Cervical cancerÂ is the second most common cancer in women aged 15-44 years, affecting the cervix- the lower part of theÂ uterusÂ that connects it with the vagina. Most cases of cervical cancer are caused by sexually acquired infection of some strains of the Human Papilloma Virus (HPV).
With the advent of an authentic, non-invasive and cost effective screening technique, the incidence of this cancer has decreased manifolds, especially in the western world where most countries have instituted large scale screening programs for this disease. However, in India thousands of women continue to die every year from cervical cancer, particularly in rural areas where it still causes greater mortality than breast cancer.
If you are experiencing any abnormal vaginal discharge or bleeding, discomfort during sexual intercourse or general pelvic pain, make sure you consult your doctor immediately as these symptoms may be warning signs of cervical cancer. Other symptoms of the disease include loss of appetite, weight loss, fatigue, back pain, leg pain, swollen legs, bone fractures, and/or (rarely) leakage of urine or feces from the vagina. Bleeding after douching or after a pelvic examination is another common sign of cervical cancer.
Yet, in most cases cervical cancer does not present with any signs until it has spread well past the cervix to other parts of the body. The disease can be detected in pre-cancerous stage only through regular screening.
Cervical screening: The tests and guidelines
Cervical screening is the best way to detect cervical cancer at an early stage, and increases the rate of successful treatment.
Cervical cancer screening requires a doctor or a nurse who takes the exfoliated cells from the surface of the cervix and a pathologist who detects early changes of cancer, if present. Liquid based cytology (LBC) and PAP tests are the two main methods of cervical screening. Both these tests are non-invasive and essentially painless. These tests are important for disease prevention, as they help in detecting any abnormal cell growth in the cervix before it turns cancerous. Screening is recommended for women between 21 and 65 years as majority of women diagnosed with cervical cancer areÂ under 50 years of age; very few are over 65 years of age.
Â The guidelines:
- Cervical screening (PAP or LBC) should start at the age of 21 years and should be performed after every three years till the age of 65 years.
- It is discouraged before this age regardless of sexual initiation or other high risk factors.
- Women can also get a combined Human Papilloma virus (HPV) test and PAP test every 5 years starting at the age of 30 years.
- If any abnormality is detected, the testing should continue for 20 years from the time of detection.
About 6.6% of women are estimated to harbor cervical HPV infection at any given time. Almost 75% of all sexually active adults are likely to be infected with at least one HPV type in their lifetime.
While a majority of the HPV infections resolve on their own, some of them turn cancerous. It takes 15 to 20 years for cervical cancer to develop in women with normal immune systems. It can take only 5 to 10 years in women with weakened immune systems, such as those with an untreated HIV infection.
There are currently 2 vaccines that protect against both HPV 16 and 18, known to cause at least 70% of cervical cancers. Clinical trials have found these vaccines to be safe and effective in preventing infection with HPV 16 and 18. The vaccines must be administered before the first sexual activity. WHO recommends vaccination for girls aged 9-13 years as this is the most cost-effective public health measure against cervical cancer. If every female adheres to currentÂ HPV vaccination programs, cervical cancer rates will be reduced substantially.
However, HPV vaccination does not undo the need for cervical cancer screening, which is recommended for all women, even those who have undergone vaccination.
Other risk factors include:
- Long-term use of hormonal contraceptives
- Early initiation of sexual activity
- Multiple sex partners
- Tobacco smoking
- Co-infection with HIV
- Poor hygiene
- Diet low in antioxidants
Treatment options vary according to the stage of the cancer and other clinical factors that include maintaining fertility and pregnancy.
- Early cervical cancer is treated by various surgical modalities that include cryosurgery, laser surgery, cold knife conization, loop electrosurgical excision procedure, and hysterectomy.
- If the cancer spreads to the lymph nodes and lymph vessels, a radical hysterectomy with the removal of pelvic lymph nodes is done.
- Advanced cancers require surgery, radiation and chemotherapy. Various targeted drugs are also added to the chemotherapy regimen.