Differences in the risk of cervical cancer and human papillomavirus infection by education level.
BACKGROUND
Cervical cancer risk is associated with low education even in an unscreened population, but it is not clear whether human papillomavirus (HPV) infection follows the same pattern.


METHODS
Two large multicentric studies (case-control studies of cervical cancer and HPV prevalence survey) including nearly 20 000 women. GP5+/GP6+ PCR was used to detect HPV.


RESULTS
Education level was consistently associated with cervical cancer risk (odds ratio (OR) for 0 and >5 years vs 1-5 years=1.50, 95% confidence interval (CI): 1.25-1.80 and 0.69, 95% CI: 0.57-0.82, respectively, P for trend <0.0001). In contrast, no association emerged between education level and HPV infection in either of the two IARC studies. A majority of the women studied had never had a Pap smear. The association between low education level and cervical cancer was most strongly attenuated by adjustment for age at first sexual intercourse and first pregnancy. Parity and screening history (but not lifetime number of sexual partners, husband's extramarital sexual relationships, and smoking) also seemed to be important confounding factors.


CONCLUSIONS
The excess of cervical cancer found in women with a low socio-economic status seems, therefore, not to be explained by a concomitant excess of HPV prevalence, but rather by early events in a woman's sexually active life that may modify the cancer-causing potential of HPV infection.
Franceschi
S
S
International Agency for Research on Cancer, 69372 Lyon cedex 08, France. franceschi@iarc.fr
Plummer
M
M
Clifford
G
G
de Sanjose
S
S
Bosch
X
X
Herrero
R
R
Muñoz
N
N
Vaccarella
S
S
D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D004522:Educational Status; D005260:Female; D006801:Humans; D016017:Odds Ratio; D027383:Papillomaviridae / Q000235:genetics / Q000302:isolation & purification; D030361:Papillomavirus Infections / Q000453:epidemiology* / Q000821:virology; D012044:Regression Analysis; D012307:Risk Factors; D002583:Uterine Cervical Neoplasms / Q000453:epidemiology* / Q000821:virology