From Which Age and with Which Interval Should Pap Smear Be Conducted?

To determine the incidence of pre invasive and invasive cervical lesions and the effective age of doing Pap smear in Kermanshah, western Iran this study was conducted.

A descriptive, cross sectional study was performed between March 2004- March 2007 and all Pap smears were analyzed according to Bethesda II system. Data were analyzed with SPSS software, mean and standard deviation tables. Effectiveness was estimated as ratio of number of HSIL and invasive carcinoma detected to all Pap smears.

A total of 148472 smears were analyzed. 99.7 % of smears were negative, only 0.3% had cytological abnormalities. ASCUS, LSIL, HSIL and carcinoma was 205.4, 73.4, 21.6 and 5.4 per 100,000 Pap smear, respectively. Incidence of HSIL was 4 times to carcinoma. The incidence of HSIL and carcinoma totally was 26.9 per 100,000 smears. Before age 35 yr, we had not any HSIL or carcinoma. Therefore, effectiveness of Pap smear before age 35 yr was zero. Most incidence of invasive cervical carcinoma was seen in age 45- 49 yr.

There was no HSIL or carcinoma before age 35, and since for changing one LSIL to HSIL to carcinoma it must pass more than 5 years, the results of this study suggest that Pap smear before 35 years old is not effective in Kermanshah and we suggest commencement of Pap smear in Kermanshah, from age 30 yr to diagnosis LSIL or ASCUS before changing to HSIL. Because there was no HSIL or carcinoma before age 35 yr, Pap smear before age 35 yr is not cost- effective.