Mammographic parenchymal patterns: value as a predictor of hormone dependency and survival in breast cancer.

The relation between the parenchymal pattern of the breasts as demonstrated on a mammogram and the estrogen-receptor status of the primary tumor in 337 patients with operable invasive breast cancer has been studied. These factors have also been correlated with the response to endocrine therapy in 92 patients who subsequently developed secondary disease. It has been shown that patients with a DY pattern are more likely to develop tumors that are estrogen-receptor (ER) positive (p = 0.01). Patients with secondary disease who have a DY pattern are more likely to respond to endocrine therapy (p = 0.001). The DY pattern has been shown to be at least as good an indicator of the probability of response to endocrine therapy as the estrogen-receptor status, and a combination of the two factors better than either taken singly. In a series of 141 postmenopausal women, the DY pattern, as determined at the time of mastectomy, was associated with significantly improved survival (p = 0.001). Mammographic parenchymal pattern could form the basis for selecting patients for endocrine therapy where no estrogen-receptor assay is available.