Adenocarcinoma of the Uterine Cervix Detected Over Long-Term Mass Screening in Japan

We retrospectively reviewed the history, records of detailed examination and/or treatment, and cytologic/histologic specimens of 32 adenocarcinoma cases (0.006%) detected among 482,451 examinees in a mass screening for cervical cancer conducted over a 20-year period (1975-1994). The detection rate of adenocarcinoma had increased gradually until 1989 with the increase of total examinees but became markedly lower in the last five-year period (p = 0.0227), probably because of the significant decrease in the number of initial examinees (p<0.0001). The frequency of early-stage adenocarcinoma (stage 0 or Ia) was 37.5% (12/ 32), markedly higher than the 8.4% (7/83) of the adenocarcinoma cases treated at our institution during the same period (p = 0.0004). Glandular epithelial neoplasms were suggested by cervical smears at detection in only 5/12 (41.7%) of the early-stage adenocarcinoma cases and in 17/ 20 (85.0%) of the frankly invasive adenocarcinoma cases (p= 0.0184). Atypical glandular epithelial cells could not be found in the smears at detection from the remaining 10 cases. Atypical cells from coexisting squamous cell neoplasms were found. The rate of the histologic coexistence of squamous cell neoplasms was 9/12 (75.0%) in the earlystage group and 6/20 (30.0%) in the frankly invasive group (p = 0.0269). This rate tended to decrease with the progress of the stage. Mass screening can detect early-stage adenocarcinoma in cervical smears, but half or more of the cases are discovered in smears with atypical cells from coexisting squamous cell neoplasms and incidentally found later in histologic specimens. To improve the accuracy of detecting cervical adenocarcinomas, we should investigate the cytologic features of atypical glandular epithelial cells obtained from early-stage adenocarcinomas. The its epidemiologic profile of this cancer should be furthur delineated for efficient mass screening programs