How is cervical cancer related to HPV?
The link is direct. The Centre for Health Protection states that about 90 per cent of cervical cancers in Hong Kong are caused by HPV types 16, 18, 31, 33, 45, 52 and 58, and that the nine-valent vaccine covers those seven genotypes.
HPV is a group of more than 150 virus types, about forty of which infect the genital organs. Infection itself is common and usually clears on its own; it is persistent infection with certain types that leads to pre-cancerous change and cancer. That is precisely why screening exists — the aim is not to find cancer but to find abnormality before cancer forms.
At what age should screening start?
The Department of Health’s Cervical Screening Programme recommends by age and sexual history rather than a single rule: women aged 25 to 29 and those aged 30 to 64 who have ever had sex follow different arrangements, and those aged 21 to 24 depend on risk factors.
| Age | Recommendation | Condition |
|---|---|---|
| 21 to 24 | Screening as assessed and advised by a doctor | Has had sex and carries risk factors for HPV infection or cervical cancer |
| 25 to 29 | After two consecutive normal annual cytology results, every three years | Has ever had sex |
| 30 to 64 | HPV testing every five years; or co-testing every five years; or, after two normal annual cytology results, cytology every three years | Has ever had sex |