Benign breast tumors – frequency, epidemiology

The frequency of benign breast diseases cannot be accurately estimated. The subjectivity of any self-assessment of one’s own mammary glands, as well as discrepancies in the medical descriptions of breast diseases, make any clinical comparisons unreliable.

In order to ensure reproducible results, most studies rely on biopsy data for benign diseases. This approach is also subject to a systematic error, since not every woman with a nodal education in the mammary gland performs a biopsy; The biopsy decision is affected by the presence of other risk factors for a malignant tumor.

According to clinical data, benign breast changes are widespread, affecting approximately 50% of women. According to a case-control study conducted by Cole et al. From 1968 to 1969 in Boston, the age-standardized incidence of histologically confirmed cystic fibrosis mastopathy and fibroadenoma was 89.4 and 32.8% per 100,000 women per year, respectively.

The authors found that their frequency increased at the age of 45, and then sharply reduced. However, the results of this study were influenced by reliance on the results of the biopsy and, possibly, the underestimation of the frequency of such conditions in younger women.

Hislop and Elwood conducted a 30-year cohort survey of British Columbian nurses and found that by the age of 50, the cumulative risk of benign breast disease was 17% in women undergoing biopsy and 31% in women who had symptoms.

Davis summarized the results of 8 post-mortem studies conducted before 1964, and found that cystic mastopathy was observed in 58.5% of all 725 mammary glands studied in women who had no signs of their diseases during their lifetime. In 43% of women, cystic mastopathy was found in both glands. The overall frequency of large cysts was 21%, while the total frequency of macroscopic and microscopic cysts and cystic mastopathy with epithelial hyperplasia was 58.3 and 30.6%, respectively.

Kramer and Rush studied the mammary glands in women older than 30 years and found histological evidence of fibrocystic mastopathy in 67% of cases. Thus, although the frequency of clinical manifestations may decrease during the postmenopausal period, histological changes persist.