Screening as a prognostic factor in cervical cancer: analysis of survival and prognostic factors based on Icelandic population data, 1964-1988.

Survival rates were computed for 376 women diagnosed with carcinoma of the uterine cervix between 1964 and 1988. The 5-year survival rate for the entire group was 63%. The effect of age at diagnosis, clinical stage, histopathology, year of diagnosis, and screening program attendance was studied by univariate analysis and simultaneously with a multivariate analysis, the Cox proportional hazards model. All these parameters had a significant effect on survival, with clinical stage as the strongest parameter followed by histology, year of diagnosis, age at diagnosis, and attendance at screening. Women who had attended the cervical screening program fared significantly better than those who had never attended. Patients treated in the late years of the study period had a significantly better survival rate, possibly indicating improved treatment. Young women had a significantly better prognosis than older women. Women with adenocarcinoma and anaplastic tumors had a significantly worse prognosis than women with squamous and adenosquamous carcinoma. The prognostic effect of screening was mainly attributed to the more favorable distribution of early stages and younger age at diagnosis among the screened women. After all the analyzed parameters had been adjusted for the nonattenders still had poorer prognosis.