HPV and cervical cancer

• Genital human papillomavirus (HPV) infection is a very common sexually transmitted infection. Most HPV infections have no symptoms and resolve without treatment
• It is estimated that about 80% of sexually active women will become infected at some point in their lives and probably as many men
• Sexual behaviour is an important predictor of acquiring an infection. If used properly and consistently, condoms will give good protection against infection with HPV
• There are about 200 types of HPV. Over 40 types infect the anogenital area and of these about 15-20 types are termed ‘high risk’ Persistent infection with ‘high risk’ types can lead to abnormal precancerous cells developing. Without treatment these cells may progress to invasive cervical cancer
• HPV type 16 is reported to be the most common ‘high-risk’ type and may be found in approximately half of all cervical cancers. HPV type 18 may account for around 10 percent of cervical cancers. Other “high risk” HPV types that may cause cervical cancer include types 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, 68, 73
• Although there may be no symptoms, many women with HPV infection develop mild cytological abnormalities of the cervix, but most of these resolve without treatment. Most women (especially those under 30 years) who get HPV will clear it in 6-24 months without even knowing they had it
• Only women with a persistent infection (one which does not clear on its own) with a high risk HPV type are at risk of cervical cancer. However these abnormal cells (pre-cancer) can be detected by screening and removed at colposcopy
• Genital warts are caused by ‘low risk’ types of HPV that are not associated with cervical cancer
• There is no treatment for persistent HPV infection itself, however, there is treatment for precancerous cervical cell changes that HPV can cause
• Having a smear test every three years is the best way to detect changes to the cells of the cervix that may later lead to cancer
• In New Zealand, the most important risk factor for developing cervical cancer is never or only rarely having been screened (cervical smear testing)
• Having regular cervical smears can reduce a woman’s risk of developing cancer by 90 per cent
• Smoking can increase a woman’s risk of HPV becoming persistent and the development of cervical cancer.

HPV vaccine

• Immunisation is now available to help protect young women against the two common types of high-risk HPV (types 16 and 18) that cause up to 70% of cervical cancer
• Two HPV vaccines are licensed for use in New Zealand
• The Gardasil® vaccine is highly effective in protecting against infection with the HPV types 16 and 18 and also the two common types of low-risk HPV (types 6 and 11) and that cause up to 90% of genital warts but do not cause cervical cancer. It is licensed for use with girls aged between 9 and 26 years
• Another HPV vaccine (Cervarix®) is effective in protecting against infection with HPV types 16 and 18 but is not publicly funded.
  HPV vaccines are most effective if given before young women become sexually active
• Protection is expected to be long lasting. Ongoing studies show that five years after being immunised, protection from infection with these HPV types remains high
• HPV vaccines protect against infection with the genotypes in the vaccine provided the woman is not already infected with those genotypes. It is not a treatment
• The vaccine does not protect against all HPV types. A woman may still become infected with another HPV genotype not included in the vaccine
• Whether women choose to be immunised against HPV or not, they will still need to participate in regular cervical screening. Together, screening and immunisation will offer the most effective protection against cervical cancer
• The vaccine is included on the National Immunisation Schedule for girls in school year 8 (or age 12 if not given at school).  A catch-up programme is also offered to girls and young women born on or after 1 January 1990. This means it is available at no cost for girls of this age range
• The vaccine is given in three doses, usually an initial dose with follow-ups two months and six months afterwards
• The vaccine is widely used internationally and has been found to be safe in large clinical trials
• Women and men may choose to purchase this vaccine privately at a cost of about $450 - $500. More about the vaccine can be found at http://www.cervicalcancervaccine.govt.nz/

HVP testing

• In some situations, women having a cervical smear test will also be offered an HPV test
• HPV testing is an accurate way to tell if a high-risk type of HPV is present in a woman’s cervix
• The HPV test detects whether HPV genetic material (DNA) from any of the 13-14 types of HPV most commonly associated with cervical cancer is present in the specimen
• HPV testing is a useful addition to cytological examination of smear tests in some circumstances
• HPV testing helps to determine those women who need further assessment and those who don’t
• The HPV test is usually done at the same time as the cervical smear test using some of the same sample of cells from the liquid based specimen
• HPV testing is a very sensitive test. A negative test result indicates a woman is extremely unlikely to be at risk of developing cancer at this stage
• A positive HPV test means a woman has high risk HPV. She should be monitored to see that the infection goes away and that she does not develop abnormal cells. It does not mean that a woman has cancer. It is important that follow-up appointments are attended so any cell changes can be found and treated early
• There is currently no approved HPV test for men or in fact clinical utility for this
• More information  on HPV testing and the meaning of test results can be found in this fact sheet for women
• Screening for high risk HPV is usually carried out as recommended by the NCSP’s Guidelines for Cervical Screening in New Zealand
• The ongoing interactive effects of cervical screening and HPV immunisation will be monitored and will need to be carefully managed to ensure an optimal programme for New Zealand women.