The epidemiology of cervical neoplasia
La Vecchia, C.
Biomedicine and PharmacoTherapy 39(8): 426-433
1985
ISSN/ISBN: 0753-3322 PMID: 3841750 Document Number: 254167
Data from northern Italy are interpreted, along with indications from the literature, to examine the role of risk factors in development of invasive and preinvasive cervical cancer. This case-control data included 183 cases of histologically confirmed cervical neoplasia in women aged 19-71. Mortality has fallen since the 1950s, starting with younger age groups, but since the 1970s, this trend has flattened out, again, starting with younger age groups. Probably changes in life-style as well as less rigorous Pap smear testing are responsible. This study found that risk of moderate dysplasia is a function of time since last smear, but that of invasive cancer depends on the number of smears, suggesting that squamous carcinoma evolves from dysplastic lesions. Both pre-invasive and invasive cancer were positively related to number of sexual partners and age at 1st intercourse. Intraepithelial neoplasia was strongly associated with Condylomata acuminata (genital warts), and trichomoniasis, and (not significantly) with Herpes genitalis and salpingitis. Invasive cancer was not related to any venereal diseases. The risk of intraepithelial neoplasia was elevated within 20 years after starting smoking, but did not increase afterward. In contrast, the risk of cervical cancer was not increased for the first 20 years of smoking, but increased steadily thereafter, to 3-fold after 40 years of smoking. Beta-carotene intake (reflected by vegetable consumption) had a powerful negative association with invasive cervical cancer. No such relationship was apparent with retinol (preformed vitamin A, indicated by dairy and meat consumption).