Human papillomavirus infection and invasive cervical cancer in Paraguay

HPV types 16 and 18 have been categorized as human carcinogens based on the ir strong associations with cervical cancer in previous case-control studie s. Recent IARC studies in the Philippines, Thailand and Morocco show strong associations between invasive cervical cancer and less common HPV types, i ncluding HPV 31, 33, 45, 51, 52 and 58, We present results of a further IAR C case-control study conducted in Asuncion, Paraguay, to examine the associ ation between specific HPV types and invasive cervical cancer as well as ri sk factors other than HPV, One-hundred thirteen incident histologically con firmed invasive cervical cancer cases and 91 age-matched hospital controls were recruited. A standardized questionnaire was administered to investigat e known and suspected risk factors for cervical cancer. For HPV status dete rmination, cervical biopsy specimens from case subjects and exfoliated cerv ical cells from control subjects were obtained. HPV DNA was ascertained usi ng a GP5+/6+ PCR-based assay capable of detecting more than 33 HPV types. O verall HPV prevalence was 97% in the cervical cancer cases and 20% in the c ontrol subjects. As a single infection, HPV 16 was the predominant type wit h a prevalence of 48% among case subjects and 5.5% among control subjects. Significant associations with the risk of cervical cancer were detected as follows: any HPV type (OR 114; 95% CI: 36-361); HPV 16 (OR = 910); HPV 18 ( infinite OR); HPV 31 (OR = 110); HPV 33 (OR = 261); HPV 45 (OR = 129); and HPV 58 (OR = 36). In the multivariate model, risk factors other than HPV si gnificantly associated with cervical cancer risk were a higher number of li fetime sexual partners, lower educational status and never having had a Pap smear. Strong associations were found between invasive cervical cancer and specific HPV types 16, 18, 31, 33, 45 and 58. Int. J. Cancer 85:486-491, 2 000. (C) 2000 Wiley-Liss, Inc.