The cytological screening turned out effective also for adenocarcinoma: a population-based case-control study in Trento, Italy

To evaluate the effectiveness of a cytological screening to prevent invasive cervical cancer in the province of Trento, a northern Italian area where a population-based cancer registry is active. The history of Pap test was evaluated through a case-control study in 61 population-based invasive cervical cancer patients, incident during 1995-2000, and in 244 age-matched (between 25 and 75 years old) controls. Women who had at least one Pap test had a reduced risk of invasive carcinoma of 80% (odds ratio= 0.20; 95% confidence intervals 0.10-0.40). The protection of a previous Pap test for both squamous cell carcinoma (odds ratio=0.23; 95% confidence intervals 0.09-0.58) and adenocarcinoma (odds ratio=0.24; 95% confidence intervals 0.07-0.78) was similar. The overall protective effect of the Pap test was not seen among younger women (<40 years). The protective effect of the Pap test seems to be stronger for shorter intervals. Our study confirms that Pap-test screening, particularly in middle-aged and older women, is an effective public health intervention with encouraging results also for the prevention of cervical adenocarcinoma.