ANALYSIS OF PARENCHYMAL DENSITY ON MAMMOGRAMS IN 1353 WOMEN 25-79 YEARS OLD

OBJECTIVE. This study was undertaken to determine the frequency and di stribution of dense mammograms. Factors' that may affect parenchymal d ensity of breasts among the diverse age groups of women who undergo ma mmography were also studied. MATERIALS AND METHODS. Mammograms of 1353 women between 25 and 79 years old who were grouped in 5-year age coho rts were reviewed. Breast density and the presence of benign calcifica tions were analyzed. RESULTS. Parenchymal density on mammograms decrea sed progressively in the patient cohorts 25-29 years old through 75-79 years old (Spearman correlation, p<.01). In the cohort of 25- through 29-year-old patients, 38% had predominantly (>50%) fatty breasts. In the cohort of 75- through 79-year-old patients, 76% had predominantly fatty breasts. Increased parenchymal density mammograms were more comm on in women who had smaller breasts, had had fewer than two pregnancie s, and underwent hormone replacement (p<.01). Forty nine percent of wo men 50-79 years old undergoing hormone replacement had predominantly d ense breasts, a percentage similar to that (48%) of the patient cohort of women 40-44 years old. Prevalence of benign calcifications also in creased with age, from 8% at ages 25-29 to 86% at ages 75-79 (p<.01). CONCLUSION, In our study, a significant percentage (38%) of women who were 25-39 years bid had predominantly fatty breast tissue that should not impede selective mammographic screening or diagnostic efforts in this age group.