Cervical screening is one of the most successful cancer prevention programmes. New Zealand changed to a simpler, more effective HPV-based test in September 2023. Understanding how the new system works helps you stay well informed about your own care.
Cervical cancer is one of the few human cancers that is almost entirely preventable through regular screening and vaccination. In New Zealand, approximately 160 women are diagnosed with cervical cancer each year, and about 50 women die from it. These numbers would be far higher without screening. The disease develops over a long period, often 10 to 20 years, from initial infection with a virus called human papillomavirus (HPV) to the development of precancerous changes and then invasive cancer. This lengthy window is precisely why screening works so well: we can detect the virus or early cell changes long before cancer develops, and treat them before any serious disease occurs.
When cervical cancer is detected by screening at an early stage, treatment is usually simple, highly effective, and has minimal impact on future fertility or health. The vast majority of women whose cervical cancer is detected early are cured. In contrast, cervical cancer detected late, at a stage where the cancer has spread beyond the cervix, is much more difficult to treat and carries a much worse prognosis. Without screening, cervical cancers typically present late because early changes cause no symptoms. By the time a woman notices bleeding or discharge, the cancer may already be advanced. This is why screening is so important: it detects disease before symptoms appear, when treatment is most effective.
The screening programme is designed to be acceptable to women by being convenient (free, locally available), accurate (modern testing is highly sensitive and specific), and to minimise unnecessary treatment. The schedule has been carefully designed to detect cancer risk while avoiding over-investigation.
HPV, or human papillomavirus, is a very common sexually transmitted infection. There are over 100 types of HPV, but only some are associated with cancer. The high-risk types (particularly HPV 16 and 18, along with several others) can cause changes in the cells of the cervix that may, if not cleared by the immune system, progress to cervical cancer over many years. Most sexually active people encounter HPV at some point during their lifetime. The good news is that most infections are cleared by the immune system within 1 to 2 years without causing any permanent damage. Only when the virus persists, usually because of certain genetic factors or immune system characteristics, does there become a risk of cell changes leading to cancer.
A crucial point to understand is that HPV infection itself causes no symptoms. You cannot tell you have HPV by how you feel. There is no vaginal discharge typical of HPV, no pain, no bleeding. This is why screening is essential: HPV can only be detected by a test. If you waited for symptoms, you would be waiting until the cancer had already developed, at which point treatment becomes much more complicated. Screening finds the virus before this happens.
The presence of high-risk HPV does not mean you have cancer or will definitely develop cancer. It means there is a risk that requires follow-up. This is why the screening programme is structured to identify women with persistent HPV infection and monitor them carefully. For most women, even those with HPV detected, no treatment is necessary beyond careful monitoring, because their immune system will clear the virus.
A cervical screening appointment takes only a few minutes. You will be asked to lie on an examination couch with your legs apart or in stirrups. A speculum, a plastic instrument shaped like a duck's bill, is gently inserted into the vagina. This spreads the walls of the vagina so the cervix can be visualised. Some people find this uncomfortable, though it should not be painful. If it is painful, tell your nurse or doctor immediately, as this might indicate an underlying issue. A speculum comes in different sizes, and your clinician can use a smaller size if the standard size is uncomfortable.
Once the cervix is visible, the clinician uses a soft brush or spatula to take a sample of cells from the cervix. This sample is placed into a liquid preservative and sent to a laboratory. The test itself takes about 1 to 2 minutes. You may feel a slight sensation as the sample is taken but it should not hurt. If you experience pain, again, tell your clinician.
Some women find the thought of the examination more worrying than the experience itself. If you have experienced trauma, feel anxious about the examination, or have specific concerns, tell your GP or nurse before the appointment. Many practices can adjust their approach, offer longer appointment times, or use different techniques such as self-sampling in certain circumstances. Your comfort and consent are important. You can also ask to have a support person present or request a female clinician if that would help you feel more comfortable.
HPV not detected. This means no high-risk HPV virus was found in your sample. Your risk of cervical cancer is very low. You should attend for screening again in 5 years as part of the routine programme. You can be reassured by this result.
HPV detected, no cell changes. This means the high-risk HPV virus is present in your cervix, but the cells of the cervix look normal under the microscope. This is actually quite common, and in most cases, your immune system is clearing the infection and it will disappear. You will be asked to come back for a repeat screening test in 12 months. This is not because something is necessarily wrong, but to confirm that the virus has been cleared. Most women with this result will have a negative HPV test at the 12-month check.
HPV detected with low-grade cell changes. This means HPV is present and there are minor changes in the appearance of the cervical cells. This does not mean cancer, it means there are early changes that require further assessment. You will be referred for colposcopy, which is a closer examination of the cervix using a special magnifying instrument. Colposcopy is not painful, though you may feel mild discomfort during the examination.
HPV detected with high-grade cell changes. This means more significant cell changes are present. You will be referred urgently for colposcopy and possibly treatment. Again, this is not a diagnosis of cancer, but rather early changes that need to be dealt with before they could progress to cancer.
Cervical cancer. This is an extremely rare finding from cervical screening because the whole point of screening is to detect disease before it becomes cancer. If cancer is found, you will be referred urgently to a gynaecology oncology specialist for further assessment and treatment.
All young people in New Zealand in Year 8 (ages 11-12) have access to the HPV vaccine, Gardasil 9, free of charge. This vaccine protects against nine strains of HPV: types 6, 11, 16, 18, 31, 33, 45, 52, and 58. Types 16 and 18 are responsible for the majority of cervical cancers, and the other types cause many of the remaining cases. Overall, the vaccine protects against the strains responsible for approximately 90% of cervical cancers worldwide.
The vaccine works by training the immune system to recognise and fight the HPV strains it protects against, before exposure to the virus occurs. It is most effective when given before someone becomes sexually active and encounters HPV naturally. The vaccine cannot treat an existing HPV infection, so it works as a preventive tool. Young women who were vaccinated still need to attend cervical screening, because no vaccine protects against all HPV strains, and some people may have been exposed to certain types of HPV before vaccination.
If you are a woman who received HPV vaccination as a teenager, you are at lower risk of cervical cancer than unvaccinated women, but your risk is not zero. You still need to attend cervical screening. The screening programme is designed to protect both vaccinated and unvaccinated women, and all women benefit from participation. Similarly, if you are a woman born before the vaccination programme began, you were never offered the vaccine, but you can still benefit greatly from cervical screening. The vaccine and the screening programme work synergistically, each providing protection that the other does not.
| Result | What it means | Next step |
|---|---|---|
| HPV not detected | No high-risk HPV found. Low risk. | Routine screen in 5 years |
| HPV detected, no cell changes | High-risk HPV present but cells look normal. Body likely clearing the virus. | Repeat screen in 12 months |
| HPV detected, low-grade cell changes | HPV present with minor cell changes. Early changes requiring assessment. | Colposcopy referral for closer examination |
| HPV detected, high-grade cell changes | HPV present with more significant cell changes. Requires specialist assessment. | Urgent colposcopy referral, possible treatment |
| Cervical cancer | Rare screening finding requiring urgent specialist care. | Urgent referral to gynaecology oncology |
Contact your GP promptly if you have any of the following symptoms:
These symptoms are not necessarily cervical cancer, but they should always be checked promptly. Early assessment of symptoms leads to better outcomes.
For further information or to book a cervical screening appointment, contact your GP or practice nurse. Healthline 0800 611 116 can provide general health information. If you identify as Maori or Pacific Islander, ask your GP or Healthline about programmes tailored to your community.