Risk factors and occult breast cancer in young women.

The National Cancer Institute guidelines for mammography in women 35--49 years old are challenged. Forty-nine occult breast cancer patients under 50 years of age were analyzed regarding risk factors and compared with an age-matched control group. Of the cancers, 86% would have been missed had NCI recommendations been followed. Results refuted the NCI guidelines and showed that late parity (over 28 years) and history of breast cancer in the extended family are statistically significant risk factors. Negative mode low-dose xeromammographic examinations permitted detection of 49 occult breast cancers, usually without axillary node metastases. Patients were screened because of risk factors enumerated in the article.