Cancer is the uncontrolled growth of body cells and can start almost anywhere in the human body. When cancer develops in the cervix of female it is termed as cervical cancer or cancer cervix. Cervix is the lower part of the uterus and connects the body of the uterus to the vagina (birth canal).The lower part of the cervix (ectocervix) lies within the vagina and the upper two thirds of the cervix (endocervix) lies above the vagina. Most cervical cancers originate in the area where the endocervix and ectocervix join.
Cervical cancer is the fourth most common cancer in women worldwide and second most common cancer in women living in less developed regions. World Health Organization (WHO) estimated 530 000 new cases of cervical cancer globally (estimations for 2012), with approximately 270 000 deaths (representing 7.5% of all female cancer deaths). More than 85% of these deaths occurred in low- and middle-income countries.
The highest estimated incidence rates for cervical cancer are in sub-Saharan Africa, Melanesia, Latin America and the Caribbean, south-central Asia and south-east Asia.
India has a population of 436.76 million women aged 15 years and older who are at risk of developing cervical cancer. Every year 122844 women are diagnosed with cervical cancer and 67477 die from the disease (estimations for 2012). In India cervical cancer is the second most common cancer among women and also the second most common cancer among women between 15 and 44 years of age.
Nearly all cases of cervical cancer can be attributable to Human papillomavirus (HPV) infection. HPV is a group of viruses and one of the causative agents in the sexually transmitted infections (STIs) in men and women with and without clinical lesions. HPV types (16 and 18) cause 70% of cervical cancers and precancerous cervical lesions worldwide.
Based on Indian studies about 82.7% of invasive cervical cancers showed the presence of HPVs 16 or 18 (Systematic reviews and meta-analyses of the literatures by ICO HPV Information Centre)*.
Other epidemiological risk factors for cervical cancer are early age at marriage, multiple sexual partners, multiple pregnancies, poor genital hygiene, malnutrition, use of oral contraceptives, and lack of awareness.
India also has the highest (age standardized) incidence rate as 22 (per 100,000 women per year) of cervical cancer in South Asia (estimations for 2012), compared to 19.2 in Bangladesh, 13 in Sri Lanka, and 2.8 in Iran.
Cervical cancer can be prevented by vaccinating all young females against the HPVs and by screening and treating precancerous lesions in women. In addition if cervical cancer is detected early and treated in earlier stages it can be cured.
* www.hpvcentre.net/statistics/reports/IND.pdf (Human Papillomavirus and Related Diseases Report, India, ICO Information Centre on HPV and Cancer (HPV Information Centre) 2015)
Women with early cervical cancers and pre-cancers usually have no symptom. Symptoms of cervical cancer appear only after the cancer has reached an advanced stage.
Symptoms may be:
These signs and symptoms are not specific, may be present in other conditions also, but still it is advised to consult health care professional at earliest. More severe symptoms may develop at advanced stages of cervical cancer.
There are several risk factors which increase the chances of developing cervical cancer.
The most important risk factor for cervical cancer is infection by the human papillomavirus (HPV).
Risk factors that may lead HPV infection to persist and progress to cancer:
Most of the cervical cancer and HPV infections in the early stages show no clinical signs and symptoms; precancerous lesions and early cancers can be detected by screening tests.
Screening for cervical cancer-There are 3 different types of screening tests:
Diagnostic tests for detection of cervical pre-cancer: some times, a diagnostic test is used for definitive diagnosis or confirmation of pre-cancer or cancer subsequent to positive screening results. Colposcopy, biopsy and endocervical curettage (ECC) are the commonly used diagnostic tests for cervical pre-cancer.
Cervical cancer stages-
WHO has recommended new guideline for screening and treatment to prevent cervical cancer in July 2021. The new guidelines recommend an HPV DNA based test as the preferred screening test instead of visual inspection with acetic acid (VIA) or Pap smear (cytology). WHO suggests that self-collected samples can be also used when providing HPV DNA testing.
If abnormal cells or lesions detected during screening tests, treatment is needed to excise them. It includes cryotherapy (destroying abnormal tissue on the cervix by freezing it) or Loop electrosurgical excision procedure (LEEP) when the patient is not eligible for cryotherapy.
When cancer is diagnosed, the treatment frequently requires a multidisciplinary approach with the involvement of a gynecologic oncologist, radiation oncologist, and medical oncologist. The treatment of cervical cancer varies with the stage of the disease.
Cervical cancer prevention and control: A comprehensive approach-
WHO recommends a comprehensive approach to cervical cancer prevention and control that includes three interdependent components: primary, secondary and tertiary prevention.
Primary prevention: reduce the risk of HPV infection
It begins with HPV vaccination of girls aged 9-13 years, before they become sexually active. Two HPV vaccines are there - a bivalent and a quadrivalent vaccine.The quadrivalent vaccine gives 100% protection against infection from HPV types 16 and 18, which are responsible for around 70% of all cervical cancers. It also protects against HPV types 6 and 11 that cause genital warts.
The vaccination schedule depends on the age of the vaccine recipient. WHO (March, 2016)a recommended schedule for both HPV vaccines is as-
(The vaccines cannot treat HPV infection or HPV-associated disease such as cancer, but it prevents the infection).
Some countries are vaccinating boys for prevention of genital cancers and genital warts in males.
Two vaccines (bivalent and a quadrivalent vaccine), which are licensed in more than a 120 countries, are available in India with the approval of Drug Controller General of India (DCGI). 63 countries have also included HPV vaccination to girls in their national immunization programmes. HPV vaccination for girls is recommended by Indian Academy of Pediatrics (IAP) and Federation of Obstetric and Gynaecological Societies of India (FOGSI) and Cancer foundation of India b.
Other preventive interventions may be recommended to boys and girls as appropriate are:
Male circumcision and the use of condoms have shown a significant protective effect against HPV transmission.
Secondary prevention: screening for and treating pre-cancer
Early detection, by screening all women in the target age group (30-49 years) followed by treatment of detected precancerous lesions can prevent the majority of cervical cancers. Cervical cancer screening should be an essential part of a woman’s routine health care. It detects pre-cancer and cancer among women who have no symptoms and may feel perfectly healthy. Important aspect of screening is that both precancerous lesions and early cervical cancers can be treated very successfully at this stage.
Tertiary prevention: treatment of invasive cervical cancer
The goal of tertiary prevention is to decrease the number of deaths due to cervical cancer. Women suspected of having invasive cervical cancer should be referred to facilities that offer cancer diagnosis and treatment. Appropriate treatment in early stage of cancer can result in cure. In advanced stage of cancer treatment and palliative care can improve quality of life, control symptoms and minimize pain suffering.
Five key messages (WHO)c :
New strategies for screening and treatment of cervical pre-cancer lesions for cervical cancer prevention by WHO:
The World Health Organization (WHO) has recommended the new guidelines for screening and treatment to prevent cervical cancer in July 2021. The new guidelines recommend an HPV DNA based test as the preferred test as primary screening test instead of visual inspection with acetic acid (VIA) or Pap smear (cytology).
For the general population of women-
Screen and Treat or Screen, Triage and Treat:
For women living with HIV:
Screen, triage and treat –only
(Screening and treatment approaches: