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Differences in the risk of cervical cancer and human papillomavirus infection by education level.

Franceschi S, Plummer M, Clifford G, de Sanjose S, Bosch X, Herrero R, Muñoz N, Vaccarella S, International Agency for Research on Cancer Multicentric Cervical Cancer Study GroupsInternational Agency for Research on Cancer Human Papillomavirus Prevalence Surveys Study Gro - Br. J. Cancer (2009)

Bottom Line: In contrast, no association emerged between education level and HPV infection in either of the two IARC studies.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.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.

View Article: PubMed Central - PubMed

Affiliation: International Agency for Research on Cancer, 69372 Lyon cedex 08, France. franceschi@iarc.fr

ABSTRACT

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.

Conclusion: 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.

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Distribution of women with and without cervical cancer in the International Agency for Research on Cancer case–control studies and human papillomavirus prevalence surveys, according to education level, Pap smear history*, and study area. *In case–control studies, Pap smears taken 12 months before enrolment are excluded. †Study areas in Vietnam. ‡Study areas in Thailand. §Study areas in China.
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fig1: Distribution of women with and without cervical cancer in the International Agency for Research on Cancer case–control studies and human papillomavirus prevalence surveys, according to education level, Pap smear history*, and study area. *In case–control studies, Pap smears taken 12 months before enrolment are excluded. †Study areas in Vietnam. ‡Study areas in Thailand. §Study areas in China.

Mentions: Methods have been described earlier for the 11 individual studies carried out between 1985 and 1999 that have been included in this paper (Munoz et al, 1992; Eluf-Neto et al, 1994; Chaouki et al, 1998; Chichareon et al, 1998; Ngelangel et al, 1998; Rolon et al, 2000; Santos et al, 2001; Bayo et al, 2002; Franceschi et al, 2003; Hammouda et al, 2005). Briefly, eligible cases were residents in predefined study areas, or women attending reference hospitals with incident, histologically confirmed invasive cervical cancer. A total of 2446 cases were identified, including 140 adeno- or adenosquamous invasive cervical carcinomas from six study areas (Eluf-Neto et al, 1994; Chaouki et al, 1998; Chichareon et al, 1998; Ngelangel et al, 1998; Rolon et al, 2000; Santos et al, 2001). Control women were population based in the Spanish and Colombian studies (Munoz et al, 1992) and hospital or clinic based in other study areas. They were frequency matched by 5-year age group and did not include women admitted to hospital for cancers of the anogenital tract, breast and colon, smoking-related diseases (Munoz et al, 1992), or sexually transmitted infections (Hammouda et al, 2005). A total of 2390 control women were included between 1985 and 1999 (Figure 1).


Differences in the risk of cervical cancer and human papillomavirus infection by education level.

Franceschi S, Plummer M, Clifford G, de Sanjose S, Bosch X, Herrero R, Muñoz N, Vaccarella S, International Agency for Research on Cancer Multicentric Cervical Cancer Study GroupsInternational Agency for Research on Cancer Human Papillomavirus Prevalence Surveys Study Gro - Br. J. Cancer (2009)

Distribution of women with and without cervical cancer in the International Agency for Research on Cancer case–control studies and human papillomavirus prevalence surveys, according to education level, Pap smear history*, and study area. *In case–control studies, Pap smears taken 12 months before enrolment are excluded. †Study areas in Vietnam. ‡Study areas in Thailand. §Study areas in China.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2736843&req=5

fig1: Distribution of women with and without cervical cancer in the International Agency for Research on Cancer case–control studies and human papillomavirus prevalence surveys, according to education level, Pap smear history*, and study area. *In case–control studies, Pap smears taken 12 months before enrolment are excluded. †Study areas in Vietnam. ‡Study areas in Thailand. §Study areas in China.
Mentions: Methods have been described earlier for the 11 individual studies carried out between 1985 and 1999 that have been included in this paper (Munoz et al, 1992; Eluf-Neto et al, 1994; Chaouki et al, 1998; Chichareon et al, 1998; Ngelangel et al, 1998; Rolon et al, 2000; Santos et al, 2001; Bayo et al, 2002; Franceschi et al, 2003; Hammouda et al, 2005). Briefly, eligible cases were residents in predefined study areas, or women attending reference hospitals with incident, histologically confirmed invasive cervical cancer. A total of 2446 cases were identified, including 140 adeno- or adenosquamous invasive cervical carcinomas from six study areas (Eluf-Neto et al, 1994; Chaouki et al, 1998; Chichareon et al, 1998; Ngelangel et al, 1998; Rolon et al, 2000; Santos et al, 2001). Control women were population based in the Spanish and Colombian studies (Munoz et al, 1992) and hospital or clinic based in other study areas. They were frequency matched by 5-year age group and did not include women admitted to hospital for cancers of the anogenital tract, breast and colon, smoking-related diseases (Munoz et al, 1992), or sexually transmitted infections (Hammouda et al, 2005). A total of 2390 control women were included between 1985 and 1999 (Figure 1).

Bottom Line: In contrast, no association emerged between education level and HPV infection in either of the two IARC studies.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.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.

View Article: PubMed Central - PubMed

Affiliation: International Agency for Research on Cancer, 69372 Lyon cedex 08, France. franceschi@iarc.fr

ABSTRACT

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.

Conclusion: 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.

Show MeSH
Related in: MedlinePlus