Screening for breast cancer.

The feasibility of mass population screening for breast cancer by clinical examination and x-ray mammography was studied. The results indicate that such a programme could be conducted effectively by non-medical staff and be safe from the dangers of irradiation. The response rate of women invited for screening suggests that such a service is acceptable to the general public. The additional work load produced by screening would not overburden the existing surgical services.     

Parity and breast cancer.

Data from the 1961 and 1971 Censuses in England and Wales were used to estimate the age distribution of women of various parities in 1976. Applying the age-specific incidences of breast cancer for women in England and Wales in 1975 gave the expected number of cases of that disease in 1976 and permitted an estimate of the mean age at diagnosis of breast cancer at each parity. This showed that the highest average age for breast cancer occurred in nulliparous women (65.9 years) and that the lowest age for the disease occurred in women who had borne two children (60.4 years). The figures obtained were similar to those reported in a separate study of women treated in Birmingham. The results of that study, however, may have been due to the age distribution in the population of women by parity, rather than any direct influence of parity on the speed of growth of breast cancer.     

How breast cancer presents.

A study of 501 new breast cancers in patients seen in a consulting surgical practice revealed that 87% were in patients 45 years of age or older. The patients had found 83% of the cancers. The distributions of size and stage were the same for the tumours found by the patients and those found by the referring physicians. Two thirds of the cancers had an associated visible clinical sign, demonstrating the importance of inspection in the examination of the breast. Dimpling, sometimes apparent only on manipulation of the tumour, was present with 264 of the cancers and was often associated with "minimal" lesions. Mammography was done for 63 of the breast cancers but it missed 27. Of the physician-found cancers 15 were in patients who had already had breast cancer, 4 were in patients presenting with symptomatic metastases and 14 were in women presenting with other disorders. Of the 52 cancers found by periodic examination 3 were locally advanced and 21 had axillary metastases, while among the 28 "early" cancers 12 were in women who were senile, mentally defective or psychotic. Only four of the cancers found by the physicians were in women under age 45; two were rapidly fatal, one had an axillary metastasis, and the fourth was in a woman who had had cancer of the opposite breast. The remaining 284 lesions found by periodic or routine examination in women under age 45 were benign. Thus, periodic or routine examination for unsuspected breast cancer in women under age 45 seems unjustified except in those who have already had breast cancer.