Comparative analysis of characteristics of women with cervical cancer in high- versus low-incidence regions.

OBJECTIVE: To identify particular characteristics that might help explain the markedly higher rate of invasive cervical cancer in southern China as compared with Australia.
METHODS: One hundred eighty-five women with cervical cancer were recruited between 1999 and 2001: 106 from Guangzhou and Changsha (southern China), and 79 from Sydney (southeast Australia). Demographic and risk factor information was obtained by questionnaire; clinicopathologic data were extracted from hospital records. The human papillomavirus (HPV) status of cancer biopsies was ascertained by consensus PCR assays, direct sequencing and/or Amplicor trade mark hybridisation.
RESULTS: The mean age of the Chinese was significantly lower than the Australians (44 versus 53 years), although mean age at first sexual intercourse was similar. Australian women were more likely to smoke, to report multiple sexual partners and to have a history of sexually transmitted diseases (but not of genital warts). However, they were better educated, were more frequent users of barrier contraception and were far more likely to report regular Pap smears before diagnosis. The HPV positivity rate of Chinese cancers (83%) was less than Australian tumours (90%); but HPV 16 and 18 were the most common genotypes in both populations (59% and 77%), and predominated in cancers from younger women. HPV types 58 or 59 were amplified from 12 (14%) of the Chinese but from only one Australian cancer.
CONCLUSIONS: Cervical cancer is not only more common in China but also develops at a younger age than in Australia. While significant differences in some risk factors were observed, the much lower participation in cervical screening in southern China is likely to be of greatest consequence.