Age distribution of cancer of the cervix uteriThe 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.
Material, methods, and resultsWe used cancer registration data for patients treated from 1975 to 1978 in hospitals in the North-west Thames Region. The number of registrations for invasive carcinoma of the cervix was similar for the four years studied-306 in 1975, 310 in 1976, 281 in 1977, and 278 in 1978. 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
CommentThe 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 be a significantly younger female population in the North-west Thames Region than in the country as a whole. Nationally, women in their 20s, 30s, 40s, and 50s formed 13 7%,', 11 9%', 11 1%o, and 11 9% of the total female population in 1975-7 (the figures were averaged over the three years); for 1971 the corresponding percentages are 13-80'%, 11 10%, 12 1%, and 1200%. The North-west Thames age distribution for the 20s, 30s, 40s, and 50s, also averaged over 1975-7, is 15-1%/, 13 0,' 1150%, and 1190/o. These slightly higher percentages of women in their 20s and 30s in the North-west Thames Regionless than 2%-are unlikely to account for the differences seen in the table. Furthermore, the female age distribution for the other three Registrations for carcinoma of the cervix uteri by age grouip for Enlgland and Wales and for the North-zvest Thanmes Region
