Tumor Size Measurements with Breast Magnetic Resonance Imaging (MRI) in Elderly Breast Cancer Patients: A Comparison of Breast MRI with Mammography and Ultrasound

Abstract

Background: With a rapid increase in the aging population around the world, there has been a surge in the number of elderly breast cancer patients. Magnetic resonance imaging (MRI) is commonly used in preoperative assessments for elderly patients. However, there has been no consensus on the accuracy of tumor size measurements by MRI. Objectives: To compare the accuracy of MRI versus conventional imaging methods, namely, mammography (MG) and ultrasound (US), in tumor size measurements in elderly patients and to determine the predictors of measurement accuracy. Patients and Methods: This study was conducted on 134 patients, aged 50 years or above (137 breasts with invasive cancer). The tumor size and T stage were assessed using MG, US, and MRI, and the results were compared with pathological findings. The tumor size differences between the imaging and pathological findings were classified as < 0.5 cm or > 0.5 cm. Differences in tumor size and T stage were analyzed based on age group (> 60 years vs. < 60 years), using chi-square test, Fisher's exact test, and Cohen's kappa coefficient. The diagnostic sensitivity, specificity, and accuracy were also measured. Multivariate logistic regression analysis was performed to evaluate the predictors that influenced tumor size differences. Results: Tumor size differences < 0.5 cm, T-stage agreement, and diagnostic performance for T stages > 2 were higher in the elderly group compared to the younger group on MRI. The T-stage agreement with the histopathological results was higher on MRI compared to conventional imaging methods. For diagnosis of T stages > 2, MRI showed the highest sensitivity, while US showed the highest specificity. The calcification type, dense breasts, and histological grade 3 were predictors of tumor size differences > 0.5 cm. Conclusion: The accuracy of tumor size measurements on MRI was higher in elderly patients aged > 60 years. The diagnostic accuracy further increased in elderly patients with non-dense breasts and mass-type lesions. In T-stage analysis, MRI showed the highest sensitivity, while US showed the highest specificity.