By Dr Sharad Ratna
Consultant Obstetrician and Gynaecologist
Senior Lecturer, Monash University
Master Reproductive Medicine and Fertility(UK),AM
What are the common facts about cervical cancer
Cervical cancer is the second most common female cancer worldwide, (after breast cancer) and the second most common cause of cancer deaths amongst Malaysian women and in the Asia Pacific region. Worldwide, cervical cancer is the second most common cancer in women over 15 years of age. One woman in the world dies of cervical cancer every 2 minutes. About 500,000 women globally are diagnosed with cervical cancer with an average of 270,000 deaths a year.
What causes cervical cancer
Almost all (99%) cervical cancer is caused by the Human Papilloma Virus(HPV). HPV is spread mainly through sexual contact. There are over 100 identified types of HPV most of which are harmless and exhibit no symptoms. There are 15 cancer-causing types which can lead to cervical cancer; HPV 16 and 18 together cause more than 70% of all cervical cancers in Asia Pacific and worldwide. Cancer-causing HPV types 16, 18, 45 and 31 together account for over 80% of cervical cancer cases in Asia Pacific.
Who is at risk of cervical cancer
Sexually active women are at risk of being affected by cervical cancer or more commonly by the early stages of the disease i.e cervical pre-cancer. Women at increased risk of developing cervical pre-cancer or cancer include women having several sexual partners, young women (less than 25 years of age and have had sexual intercourse at an early age of 16 years or less) or women having a male partner who has had several different sex partners
How can pap smears reduce the risk of cervical cancer
Eighty percent of cervical cancer presents at an advanced stage when the cancer may be incurable. Hence, regular cervical screening by routine cervical or pap smear examinations allows cervical cancer and pre-cancer to be detected at an early stage when immediate treatments are more effective. Effective cervical cancer screening programmes in some countries, such as, in the United Kingdom, have dramatically reduced the incidence and death from cervical cancer.
What is a pap smear test and cervical cancer screening
Cervical cancer screening involves routine Pap smear tests aimed at women with no symptoms. It is currently recommended that every woman who has had sexual intercourse have regular Pap smear tests so that problems can be detected at an early stage and thus treated before they become a serious condition like cervical cancer.
The pap smear test is a simple painless test in which cells from the cervix and vagina are examined for any abnormalities that can lead to cancer. Fortunately, some early changes in the cervix can be seen long before cancer develops. Once these changes are treated, cancer can be prevented. It is important that the pap smear examination or test is done by a properly trained and experienced medical personnel as accurate visualisation of the cervix and an appropriate sample must be taken for assessment. Nowadays, there are many screening centres in Malaysia that offer pap smear tests and other screening tests but these test are unfortunately carried out at times by untrained or non-medical personnel and this can be detrimental to the woman.
Colposcopy is one way a gynaecologist can look at the cervix through a special magnifying device that allows the gynaecologist to find problems on the cervix that cannot be seen by the naked eye alone. It is a relatively painless procedure in which the cervix is examined under magnification after a mild vinegar-like solution (acetic acid) is applied to the cervix. Biopsies of abnormal areas are taken for further evaluation and treatment can be performed based on these results.
How do cervical cancer vaccines protect against cervical cancer
Currently, there are 2 vaccines available to prevent cervical cancer. Cervical cancer vaccine helps prevent but does not treat these diseases. However, it is not a substitute for routine Pap smears for cervical cancer screening. It is estimated that in the absence of vaccination, the vast majority of sexually active people will become infected by HPV virus in their lifetime. Many people who have HPV may not show any signs or symptoms, hence they may transmit the virus unknowingly.
Cervarix® cervical cancer vaccine provides nearly 100% protection against HPV types 16 and 18 associated pre-cancerous lesions. Cervarix® induces a stronger and more sustained immune response than the other vaccine. Cervarix with AS04 adjuvant system provides cross protection against infection of HPV 45 & 31, which are the third and fourth most common types found in cervical cancer globally.(Cervarix® vaccine is indicated in females aged 10 to 25 years for prevention of cervical cancer by protecting against incident and persistent infections as well as lesions caused by cancer-causing HPV types 16 and 18. )The primary vaccination course consists of three doses, given at 0, 1 and 6 months. Most importantly, it is not a substitute for routine Pap smears for cervical cancer screening.
Gardasil®the other vaccine available is a vaccine that helps protect against HPV types 6, 11, 16 and 18 which are associated with cervical cancer, precancerous changes of the cervix and vulva, and genital warts. Children and adolescents aged 9 years and above can receive Gardasil®. The vaccine works best when given to persons with no prior HPV contact although possible benefits can be derived in persons who may have had previous HPV exposure. It is given as an injection and a complete course consists of 3 doses where the 2nd and 3rd doses are administered 2 months and 6 months after the 1st dose respectively.
These vaccines help prevent but does not treat these diseases. Again, it is not a substitute for routine Pap smears for cervical cancer screening.