Background: Ultrasound is the first-line breast imaging modality in younger patients and an adjunct to mammography in older patients. The objectives of this study were to evaluate the complementary value of ultrasound to mammography in breast cancer and to investigate the use of ultrasound in patients above and below the age of 50 years.
Methods: Clinical presentation and investigations for consecutive patients undergoing triple assessment at a symptomatic breast clinic were prospectively recorded between January 2000 and August 2003. Clinical data were compared with pathological findings. Patients were divided into two groups, above and below 50 years of age for subgroup analyses.
Results: A total of 999 of 2185 patients had both mammography and ultrasound investigations performed and constituted the study population. Subgroup analysis of the 2185 patients demonstrated that 99 of the 127 patients who were diagnosed with breast cancer had both investigations performed (median age 57.0, range: 34-89 years). Mammography was normal/benign in 14.1%, indeterminate in 29.3% and suspicious of cancer in 56.6% of patients. Adjunctive ultrasound was normal/benign in 13.1%, indeterminate in 6.1% and suspicious of cancer in 80.8% of patients. In these 99 patients, adjunctive ultrasound was more sensitive than mammogram alone (80.8% vs. 56.6%, p < 0.001). Ultrasound upgraded nine of 14 mammographically normal and 16 of 29 mammographically indeterminate X-rays to a cancer. Mammography appeared to be more sensitive in patients over 50 years compared with those patients under 50 years (62.5% vs. 45.7%, p = 0.10). The sensitivity of ultrasound was comparable between patients above and below the age of 50 years (82.8% vs. 77.1%, p = 0.60). Further subgroup analysis demonstrated a higher sensitivity with combined mammography and ultrasound compared with mammography alone in either patient group (below 50: 45.7%-->77.1% and above 50: 62.5%-->82.8%). These results also suggested that the difference in the sensitivities of mammography vs. the combined investigation approach was more marked in patients under 50 years of age (below 50 = 31.4% vs. above 50 = 20.3%).
Conclusion: Adjunctive ultrasound assessment improves breast cancer detection in women of all ages and should be routinely used in symptomatic breast clinics.