Tumor size estimation of the breast cancer molecular subtypes using imaging techniques

Abstract

Background and aim. In medical practice the classification of breast cancer is most commonly based on the molecular subtypes, in order to predict the disease prognosis, avoid over-treatment, and provide individualized cancer management. Tumor size is a major determiner of treatment planning, acting on the decision-making process, whether to perform breast surgery or administer neoadjuvant chemotherapy. Imaging methods play a key role in determining the tumor size in breast cancers at the time of the diagnosis.
 We aimed to compare the radiologically determined tumor sizes with the corresponding pathologically determined tumor sizes of breast cancer at the time of the diagnosis, in correlation with the molecular subtypes.
 Methods. Ninety-one patients with primary invasive breast cancer were evaluated. The main molecular subtypes were luminal A, luminal B, HER-2 positive, and triple-negative. The Bland–Altman plot was used for presenting the limits of agreement between the radiologically and the pathologically determined tumor sizes by the molecular subtypes.
 Results. A significantly proportional underestimation was found for the luminal A subtype, especially for large tumors. The p-values for the magnetic resonance imaging, mammography, and ultrasonography were 0.020, 0.030, and <0.001, respectively. No statistically significant differences were observed among the radiologic modalities in determining the tumor size in the remaining molecular subtypes (p > 0.05).
 Conclusion. The radiologically determined tumor size was significantly smaller than the pathologically determined tumor size in the luminal A subtype of breast cancers when measured with all three imaging modalities. The differences were more prominent with ultrasonography and mammography. The underestimation rate increases as the tumor gets larger.

Molecular subtypes of breast cancer: Can it be determinant for preoperative MRI planning?

“…The data about this issue are quite controversial in the literature. Gulten et al found that the pathological tumor size was larger in luminal A than in luminal B and others (32). Veli et al detected a larger tumor size in HER-2 overexpressing subtype (20).…”

Margin Assessment in Breast Conservative Surgery and Concordance between Frozen and Paraffin Section Results: A Retrospective Study

“…In another study done by Sezgın et al [22] reported that the mean age was 53.8 ± 13.4 years (median 51, range 31-90). The mean pathologically determined tumor size was 30.3 ±22.2mm (median 25mm, range 7-150mm); the tumor size was determined to be 29.4 ±21.1mm (median 24mm, range 6-138mm) with MRI, 20.1 ±8 mm (median 20mm, range 5-141mm) with MM, and 20.1 ± 11.4mm (median 18mm, range 5-66mm) with US.…”