MRI accuracy in residual disease evaluation in breast cancer patients treated with neoadjuvant chemotherapy
Introduction
Neoadjuvant chemotherapy was introduced in the 1970s and has now become a standard therapeutic option for breast cancer patients with locally advanced disease.1, 2, 3, 4 Patients with large breast cancer undergoing neoadjuvant chemotherapy might be candidates for radical therapy, or in the case of optimal response, might be treated with breast-conserving surgery with no increase in the local recurrence rate.1, 5, 6, 7 Futhermore neoadjuvant chemotherapy has improved disease-free survival in most patients and overall survival rates in patients with complete response.8, 9, 10, 11
An accurate measurement of tumour size before neoadjuvant chemotherapy is important for staging, treatment monitoring and determining patients’ prognoses. Careful evaluation of residual disease after chemotherapy is important to select the optimal surgical procedure and to identify women that do not show a significant response. If non-responders could be identified, their treatment could be changed to an alternative and potentially more effective regimen or definitive surgical treatment could be considered. Thus, accurate methods of assessment of response are needed to aid the management of patients undergoing neoadjuvant therapy.12, 13, 14
Evaluation of the extent of residual tumour after neoadjuvant chemotherapy based on clinical examination and conventional breast imaging (sonography and mammography) has been shown to be insufficiently sensitive and accurate due to chemotherapy-induced necrosis and fibrosis, and consequently, the tendency to overestimate the volume of residual disease, with important limits in treatment options.9, 12, 13, 15
Magnetic resonance imaging (MRI) has been shown to be more accurate than other imaging techniques for determining the size and extent of most breast malignancies when assessment is performed before surgery for cure.12, 13, 14, 16, 17, 18, 19
The great ability of dynamic MRI compared with conventional imaging in distinguishing fibrous from vascularized tissue is based on the evaluation of tissue morphology and signal intensity changes after contrast medium administration. The contrast medium, which has an intravascular and interstitial distribution, permeates the lesion and markedly increases the signal intensity with respect to the surrounding tissue, thus identifying the angiogenic foci. This is useful in the analysis of the degree of vascularization, and therefore of the viability of residual tumour.20, 21, 22, 23, 24
Recent studies have evaluated MRI accuracy in determining residual breast tumour after neoadjuvant chemotherapy. Generally MRI was shown to be a valid tool to assess residual disease but there are cases of MRI over- or underestimation.1, 10, 11, 19, 25, 26 Only a few studies have compared size measurements of residual tumour obtained on MRI with those obtained at pathology, and generally a good correlation was found.27, 28, 29, 30
The aim of the present study was to assess MRI accuracy in evaluating the presence and size of residual disease after neoadjuvant chemotherapy in a large patient population with large breast tumours, in order to obtain a statistically better study results and also to conduct a wide survey of the radiological patterns of response to neoadjuvant chemotherapy.
Section snippets
Materials and methods
From March 2000 to June 2003, 45 consecutive women (mean age: 53.7 years; range: 30–76 years) with breast cancer receiving neoadjuvant chemotherapy, were enrolled in the study. All patients gave their informed consent to the study and underwent MRI mammography before and after (within 15 days) neoadjuvant chemotherapy.
Results
According to TNM classification, the 45 patients included in the study were at the following stages: 14 at stage 2A, 14 at stage 2B, 11 at stage 3A, and six at stage 3B. Patients’ characteristics are summarized in Table 1.
Stage 2A patients received neoadjuvant chemotherapy because of small breast size or the peri-areolar tumour localization meant that only surgery could be curative.
The initial diagnosis was obtained with fine-needle aspiration cytology. Chemotherapy was perfomed with CMF-A-CMF
Discussion
Residual disease after neoadjuvant chemotherapy represents a critical prognostic factor in determining the success of therapy and an accurate evaluation of its size is essential for planning the correct surgical approach.8, 9, 10, 11, 12, 13, 14 A method suitable for monitoring the response to treatment should be able to provide data regarding changes in tumour size and in cellularity and vascularization. The pattern of contrast medium uptake is the parameter that should be considered in the
References (36)
- et al.
Multimodal therapy in locally advanced breast carcinoma
Am J Surg
(1990) - et al.
Pre-operative MR-mammography in breast cancer patients
Eur J Surg Oncol
(1999) An overview of interpretation strategies for breast MR imaging
Magn Reson Imaging Clin N Am
(2001)- et al.
MR mammography with pharmacokinetic mapping for monitoring of breast cancer treatment during neoadjuvant therapy
Magn Reson Imaging Clin N Am
(1994) - et al.
Neoadjuvant chemotherapy in women with invasive breast carcinoma: conceptual basis and fundamental surgical issues
J Am Coll Surg
(2000) - et al.
Contrast enhanced magnetic resonance imaging underestimates residual disease following neoadjuvant docetaxel based chemotherapy for breast cancer
Eur J Surg Oncol
(2004) - et al.
Evaluation of neoadjuvant chemotherapeutic response of locally advanced breast cancer by magnetic resonance imaging
Cancer
(1996) Evolving concepts in the systemic adjuvant treatment of breast cancer
Cancer Res
(1992)- et al.
Multimodality treatment of locally advanced breast carcinoma
Arch Surg
(1988) - et al.
Mastectomy as an adjuvant to chemotherapy for locally advanced or metastatic breast cancer
Arch Surg
(1982)
Conservative treatment feasibility with induction chemotherapy, surgery, and radiotherapy for patients with breast carcinoma larger than 3 cm
Cancer
Induction chemotherapy followed by breast conservation for locally advanced carcinoma of the breast
Cancer
Imaging in evaluation of response to neoadjuvant breast cancer treatment benefits of MRI
Breast Cancer Res Treat
Pathological assessment of response to induction chemotherapy in breast cancer
Cancer Res
Management of stage III primary breast cancer with primary chemotherapy, surgery, and radiation therapy
Cancer
MRI of breast cancer: influence of chemotherapy on sensitivity
Br J Radiol
Breast tumours: comparative accuracy of MR imaging relative to mammography and US for demonstrating extent
Radiology
Breast cancer measurements with magnetic resonance imaging, ultrasonography, and mammography
Breast Cancer Res Treat
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