Tumor Size of Invasive Breast Cancer on Magnetic Resonance Imaging and Conventional Imaging (Mammogram/Ultrasound): Comparison with Pathological Size and Clinical Implications

Abstract

Background and Aim: in landspitali university hospital, magnetic resonance imaging is used non-selectively in addition to mammogram and ultrasound in the preoperative assessment of breast cancer patients. The aim of this study was to assess invasive tumor size on imaging, compare with pathological size and evaluate the impact of magnetic resonance imaging on the type of surgery performed.Material and Methods: all women with invasive breast cancer, diagnosed in iceland, between 2007 and 2009 were reviewed retrospectively. in all, 438 of 641 (68%) patients diagnosed had preoperative magnetic resonance imaging. Twelve patients treated with neoadjuvant chemotherapy were excluded and 65 patients with multifocal or contralateral disease were assessed separately.Results: Correlations between microscopic and radiologic tumor sizes were relatively weak. all imaging methods were inaccurate especially for large tumors, resulting in an overall underestimation of tumor size for these tumors. magnetic resonance imaging under-and overestimated pathological tumor size by more than 10 mm in 16/348 (4.6%) and 26/348 patients (7.5%), respectively. in 19 patients (73%), overestimation of size was seen exclusively on magnetic resonance imaging. for tumors under-or overestimated by magnetic resonance imaging, the mastectomy rates were 56% and 65%, respectively, compared to an overall mastectomy rate of 43%. of 51 patients diagnosed with multifocal disease on pathology, 19 (37%) were diagnosed by mammogram or ultrasound and 40 (78%) by magnetic resonance imaging resulting in a total detection rate of 84% (43 patients).

Relevance of breast MRI in determining the size and focality of invasive breast cancer treated by mastectomy: a prospective study

“…While in our study, the size was underestimated in 20.5% and overestimated in 23.9% of cases, Haraldsdottir et al [8] and Grimsby et al [10] underestimated size in 4.6 and 15% of cases and overestimated in 7.5 and 33% of cases, respectively. The presence of a single DCIS [7, 28] or associated with an invasive component was cited as a possible cause of overestimation of tumour size [10]; in our study, this was only found for high-grade DCIS, which is known to enhance on MRI, even in the lack of neoangiogenesis [29].…”

“…Because of this difference, we chose a 20% concordance value between MRI and histology, rather than an absolute figure. Unlike other teams, we found it more informative to establish a percentage match threshold of histological tumour size and not a fixed difference regardless of cancer size (roughly 5 mm [7, 10] or 10 mm [8] of the size determined by histology). Indeed, this calculation allows us to have very similar real measurements for small tumours (e.g.…”

“…Other authors [8, 10] have also reported equivalent proportions of over- and underestimation of tumour size. While in our study, the size was underestimated in 20.5% and overestimated in 23.9% of cases, Haraldsdottir et al [8] and Grimsby et al [10] underestimated size in 4.6 and 15% of cases and overestimated in 7.5 and 33% of cases, respectively.…”

Unifocal Invasive Lobular Carcinoma: Tumor Size Concordance Between Preoperative Ultrasound Imaging and Postoperative Pathology

“…Receptor status 25,26 in conjunction with extent of disease 24 is important when considering neoadjuvant therapy for ILCs, especially when breast conservation is considered 24,27–29 . Breast ultrasound is a widely available modality and can be used as a complement to further characterize lesions.…”

Breast MRI: State of the Art

“…Regardless, most studies conclude that size estimations with MRI are more reliable than those with clinical examination, mammography, or US. Accuracy decreases in larger cancers and is worse in NME than in mass lesions (75)(76)(77). It is important to realize that the pathologic reference standard has substantial limitations.…”