What is cervical cancer?
Cervical cancer develops when abnormal cells in the cervix-lining multiply following viral infection. Abnormal cervical cells can form a lesion (group of abnormal cells) or lump (tumour). Malignant (cancerous) tumours can spread and grow into life-threatening cancer.
What causes cervical cancer?
- Unlike most cancers, almost all cases of cervical cancer are caused by a virus, which is why cervical cancer can be prevented by a vaccine.
- The virus that causes cervical cancers is the human papillomavirus (HPV), a common virus infecting up to 80% of the population at some time.1
- In most women, an HPV infection clears on its own. In some women, however, certain high-risk or oncogenic virus types remain and can cause cervical cancer.1
- Infection from HPV can also result in pre-cancerous lesions that can be detected through the National Cervical Screening Programme (NCSP) and present as abnormal pap smears (also referred to as smear tests).
- 70% of cervical cancer cases are attributed to high-risk HPV types 16 and 18.2
- In addition, there are different types of HPV that can result in the development of genital warts.
How common is cervical cancer?
- Worldwide, cervical cancer is the second-leading cause of cancer death in women.3
- Globally, each year around 500,000 women are diagnosed and nearly 300,000 die.3
New Zealand Incidence
- Regular screening reduces the chances of getting cervical cancer.
- Without it, one in 40 women would develop cervical cancer.
- With screening, one in 250 will develop cervical cancer.4
- Cervical cancer kills about 60 women a year.5
- One woman out of 85 would die from cervical cancer with no screening. Three yearly screening reduces this to about one in 770 women.4
- The death rate from cervical cancer for Maori women is four times as high as non-Maori women. The reason is not known however it is believed this is due to reduced compliance by Maori women with cervical screening.4
Who gets cervical cancer?
- In New Zealand, cervical cancer has the youngest age of first diagnosis compared to other cancers. It often occurs in women in their 40s and 50s, when many are still raising children and contributing to their families’ livelihoods and security.
- The 2004 audit found only a fifth of women with cervical cancer had been regularly screened, and only half had had a pap smear in the three years prior to their diagnosis.
- Maori, Pacific Island and low income women are at greatest risk as they are less likely to undergo cervical cancer screening.4
How is cervical cancer diagnosed?
- The pap smear is a simple check – usually conducted in a doctor’s office or clinic – that detects abnormal or cancerous cervical cells.
- Because the pap smear can detect cervical changes before they progress to cancer, it is credited with significantly reducing cervical cancer deaths.
- After 1 abnormal pap smear, women are advised to wait six months then repeat
- After a 2nd abnormal pap smear, women have a colposcopy (visual examination of the cervix and vagina using a lighted magnifying instrument (colposcope)).
- They are then given a range of options depending on the colposcopy result.
- Pap smear tests are not 100% accurate. In general cervical screening programmes are approximately 70% accurate.6
- Sometimes further tests do not find any cervical abnormalities that actually exist – but regular screening can help women and their healthcare providers overcome “false-negative” results.
- Pap smears sometimes show minor cervical abnormalities due to infection with low-risk HPV types, such 6 and 11. These results can be costly for the health system, but more importantly, cause unnecessary anxiety for patients who have to wait for follow-up testing and results before being cleared of having pre-cancer or cancer.
What are the symptoms of cervical cancer?
- Generally pre cancerous lesions of the cervix and cervical cancer are asymptomatic, hence the importance of having regular pap smears to detect cervical pre-cancers or cancers at a stage when they can be treated most effectively.
- As the disease progresses, women may notice one or more of the following symptoms:
- Abnormal vaginal bleeding
- Increased vaginal discharge
- Pelvic pain
- Pain during sexual intercourse
How are cervical cancer and pre-cancer treated?
- There are a number of treatment options available for cancerous and pre-cancerous cervical lesions. In each case, a woman and her healthcare provider determine the most appropriate treatment.
- Mild dysysplasia (CIN 1 - Cervical Intraepithelial Neoplasia)
- Pre-invasive stage (Stage 0 – Carcinoma in Situ)
- Moderate or severe dysplasia (CIN 2 or 3) when the cancer has affected only the outer layer of the lining of the cervix, treatment may include:
- Laser surgery to destroy abnormal cells.
- Cryosurgery to freeze cancerous and pre-cancerous lesions.
- Loop electrosurgical excision procedure (LEEP) using an electrical current to cut away abnormal cells.
- Conization surgically removes a cone-shaped piece of tissue from the cervix.
- Invasive stage (Stages 1-4) - when the cancer has penetrated beyond the cervix into the uterus and possibly other tissues and organs, treatment may include:
- Radiation to shrink tumours and destroy the cancer cells’ ability to reproduce.
- Chemotherapy to kill cancer cells, including those spread to distant organs.
- Partial, full or radical hysterectomy.
How can cervical cancer be prevented?
Prior to the development of the GARDASIL vaccine, the only form of cervical cancer prevention was to be regularly screened with the pap smear tests. However screening only detects precancerous and cancerous lesions. It does not prevent these lesions from occurring. Also there are significant NCSP compliance requirements by the population. References
1. Centers for Disease Control and Prevention. CDC Fact Sheet. Genital HPV Infection. Content Reviewed: May 2004. Technical Update: December 2, 2004. Centers for Disease Control Web site. Available at: http://www.cdc.gov/std/HPV/hpv.pdf. Accessed January 2005.
2. Muñoz N, Bosch FX, de Sanjosé S, et al. Epidemiologic classification of human papillomavirus types associated with cervical cancer. N Engl J Med. 2003; 348:518–527.
3. World Health Organisation. Geneva, Switzerland: WHO; 2003: 1-74.2. 1999: 1-22.
4. New Zealand Cancer Control Audit 2004
5. New Zealand Health Information Service (Statistics NZ figures from 1950 to 2002)
6. Chaco MS, Mattie ME, Schwartz PE. Cancer, 2003; 99:135-140.
TAPS no: PP3428.
Note: Information on this site is not intended to replace the advice given by your doctor or other health professional.