Prognostic value of response evaluation based on breast MRI after neoadjuvant treatment: a retrospective cohort study.

OBJECTIVE: To investigate the impact of response evaluation after neoadjuvant chemotherapy (NAC) in breast cancer patients, assessed by both magnetic resonance imaging (MRI) and pathology, on disease-free survival (DFS). METHODS: This single-center, retrospective cohort study included consecutive breast cancer patients who underwent NAC and preoperative breast MRI. Resolution of invasive carcinoma in the breast and axilla was defined as complete pathological response (pCR). Radiological complete response (rCR) was defined as the absence of abnormal enhancement in the tumor site. Kaplan-Meier estimator was used to estimate the disease-free survival on 60 months. Cox regression analysis was used to estimate hazard ratio (HR) values. RESULTS: In total, 317 patients were included with a mean age of 47.3 years and a mean tumor size of 39.8 mm. The most common immunophenotype was luminal (44.9%), followed by triple-negative (26.8%). Overall, 126 patients (39.7%) had an rCR, while 119 (37.5%) had pCR; the radiological and pathological responses agreed in 252 cases (79.5%). During follow-up, patients who had rCR and pCR had a better DFS curve compared to patients with non-rCR and non-pCR, while those who had rCR or pCR presented an intermediate curve (Log-rank p = 0.003). Multivariate analysis showed a higher risk of recurrence in patients with non-rCR and non-pCR (HR: 5,626; p = 0.020) and those who had a complete response on MRI or pathology only (HR: 4,369; p = 0.067), when compared to patients with rCR and pCR. CONCLUSIONS: The association of MRI and pathological responses after NAC might better stratify the risk of recurrence and prognosis in breast cancer patients. KEY POINTS: • Association of response evaluation after neoadjuvant chemotherapy by pathology and MRI allows better stratification of prognosis. • Complete response to neoadjuvant chemotherapy on pathology and MRI was related to better disease-free survival. • Complete response on MRI or pathology only had a greater risk of recurrence.

MRI Features of Mucinous Cancer of the Breast: Correlation With Pathologic Findings and Other Imaging Methods.

OBJECTIVE: Mucinous breast carcinoma is an uncommon histologic type of invasive breast carcinoma that can be differentiated in pure and mixed forms, which have different prognosis and treatment. CONCLUSION: MRI features of both types of mucinous breast carcinomas are discussed, illustrated, and compared with pathologic findings and with other imaging methods, including mammography, ultrasound, and PET/CT.

Intramammary lymph nodes: normal and abnormal multimodality imaging features.

Intramammary lymph nodes (IMLN) are one of the most common benign findings at screening mammography. However, abnormal IMLN features, such as diminished or absent hilum, thickened cortex, not circumscribed margins, increased size or interval change, warrants additional follow-up or pathologic analysis to exclude malignancy. Some benign inflammatory conditions may be associated with imaging-detected suspected abnormal IMLN, such as reactive hyperplasia and silicone-induced lymphadenopathy. In patients with known breast cancer, IMLN are a potential site of locoregional spread, which can change the prognosis and management. In some cases, initial breast carcinomas can also mimic IMLN. Breast radiologists must also be aware of the typical and atypical characteristics of IMLN to suggest further investigation when it is necessary.

Breast metastases from extramammary malignancies: multimodality imaging aspects.

Breast metastases from extramammary cancers are rare and usually related to poor prognosis. The extramammary tumours most frequently exhibiting breast metastases are melanoma, lymphomas, ovarian cancer, lung and neuroendocrine tumours, and sarcomas. Owing to the lack of reliable and specific clinical or radiological signs for the diagnosis of breast metastases, a combination of techniques is needed to differentiate these lesions from primary breast carcinoma or even benign breast lesions. Multiple imaging methods may be used to evaluate these patients, including mammography, ultrasound, MRI, CT and positron emission tomography CT. Clinical and imaging manifestations are varied, depend on the form of dissemination of the disease and may mimic primary benign and malignant breast lesions. Haematologically disseminated metastases often develop as a circumscribed mass, whereas lymphatic dissemination often presents as diffuse breast oedema and skin thickening. Unlike primary carcinomas, breast metastases generally do not have spiculated margins, skin or nipple retraction. Microlobulated or indistinct margins may be present in some cases. Although calcifications are not frequently present in metastatic lesions, they occur more commonly in patients with ovarian cancer. Although rare, secondary malignant neoplasms should be considered in the differential diagnosis of breast lesions, in the appropriate clinical setting. Knowledge of the most common imaging features can help to provide the correct diagnosis and adequate therapeutic planning.

Role of MRI in the staging of breast cancer patients: does histological type and molecular subtype matter?

OBJECTIVE: To assess the role of MRI in the pre-operative staging of patients with different histological types and molecular subtypes of breast cancer, by the assessment of the dimensions of the main tumour and identification of multifocal and/or multicentric disease. METHODS: The study included 160 females diagnosed with breast cancer who underwent breast MRI for pre-operative staging. The size of the primary tumour evaluated by MRI was compared with the pathology (gold standard) using the Pearson's correlation coefficient (r). The presence of multifocal and/or multicentric disease was also evaluated. RESULTS: The mean age of patients was 52.6 years (range 30-81 years). Correlation between the largest dimension of the main tumour measured by MRI and pathology was worse for non-special type/invasive ductal carcinoma than for other histological types and was better for luminal A and triple-negative than for luminal B and Her-2 molecular subtypes. Multifocal and/or multicentric disease was present in 48 patients (30.0%), and it was more common in breast carcinomas classified as Her-2 molecular subtype. There was no statistically significant difference in the frequency of multifocal and/or multicentric tumours identified only by MRI in relation to histological type or molecular subtype. CONCLUSION: The results of this retrospective study demonstrated that histological types and molecular subtypes might influence the MRI assessment of breast cancers, especially in the evaluation of tumour size. ADVANCES IN KNOWLEDGE: The real benefit of MRI for treatment planning in patients with breast cancer may be different according to the histological type and molecular subtype.