Age distribution of cancer of the cervix uteri.

Age distribution of cancer of the cervix uteri The most recent cancer registration data for England and Wales, relating to 1971,1 show that the peak for invasive carcinoma of the cervix occurs in the age group 50-54 years. Since early diagnosis of this disease affects prognosis, we studied more recent registration data to see whether there has been a trend towards presentation at an earlier age, and whether we need to screen younger women than the 1971 data would suggest. We used cancer registration data for patients treated from 1975 to 1978 in hospitals in the Northwest Thames Region. The number of registrations for invasive carcinoma of the cervix was similar for the four years studied-Even though registration is not complete in this region, these annual figures can be considered random samples since any bias in the completeness of registration is a function not of the patient's age but of the efficiency of the hospital's cancer registry. The age distribution of the patients is similar for the individual years 1975-8, and the combined data on 1175 registrations are compared in the table with the data for England and Wales in 1971. The basis of comparison is the percentage of the total registrations in each age group-in this instance age-specific rates are not appropriate since many patients with cancer treated in the Northwest Thames Region do not live in the region. Indeed, the extent to which patients move across some regional boundaries for treatment is not always realised, with the result that statistics based on region of residence are sometimes assumed incorrectly to be accurate statistics on region of treatment. When compared with the 1971 national data, the Northwest Thames regional figures show a trend towards an increased proportion of registrations in the 20-29 and 30-39 age groups and a corresponding reduced proportion in the 40-49 and 50-59 age groups. This is most noticeable for invasive cancer, but there is a similar trend for carcinoma in situ. Of the regional registrations for carcinoma in situ, 25 % were in the age group 28-31 years and only 12 % at 24-27 and 18 %0 at 32-35 years. Comment The age distribution of a given cancer may be the result of a complex interaction of factors and a definite explanation of empirical observations cannot always be given. One factor, however, that could give rise to the different distributions seen in the table would …