Invasive Ductal Breast Cancer, Tumor Size, And Its Correlation Between Physical Examination, Imaging Techniques, And Pathological Anatomy.

e11035 Background: The most frequent indication of magnetic resonance in breast cancer is the evaluation of tumoral extension. Several studies suggest that mammography and ultrasound underestimate tumor size. We try to analize the correlation between the tumor size of invasive ductal carcinomas in physical examination, mammography, magnetic resonance and pathological anatomy. Methods: We review the 290 magnetic resonance made in our Radiology Department from 1st January 2009 to 1st September 2010. 56 of them were applied as complementary study before surgery of suspected lesions of breast cancer. We made an analysis of paired test, and then a hypothesis test for equal sample testing, supported by an analysis of power curves. The paired test analysed were physical examination (PE)- mammography - magnetic resonance (MR) - pathological anatomy (PA). Results: A 100% were women; average of age of 54.1 years old. A 42.8% were premenopausal. Averages of tumor size: 18.3mm in PE; 18.8mm in mammography; 25.3mm in MR and 24.8mm in PA. The correlation between the tumor size in PE and PA is not statistically significant (p=0.05, 95% CI 11.07; 1.93), and also between the mammography and the PA (p=0.05, 95% CI 10.69; 1.47). The correlation between tumor size in mammography and MR is statistically significant (p=0.05, 95% CI -9.83; -3.26), and also between MR and PA (p=0.05, 95% CI -3.31; 4.25). We analysed the relation between clinical tumor size by MR and PA size, and in a 25% of the cases, the clinical and the pathological stage were different. The pathological was more advance in a 57.1% of them. Conclusions: Mammography underestimate the tumor size, with no correlation with the pathological tumor size. However, there is a good correlation between the tumor size in MR and the pathological size. The MR is the most reliable imaging technique to optimize the surgical and oncological treatment in patients with breast cancer.