Role of Shear Wave Elastography as Predictor of Immunohistochemistry Profile in Breast Cancer.

BACKGROUND

Breast cancer is a heterogeneous malignancy with varied molecular subtypes having divergent prognosis. Immunohistochemistry (IHC) is the guiding investigation for both prognosis and therapy. IHC although pertinent, still lacks ubiquity thus precluding the need for a readily available modality for assessment of tumor biology. Shear wave elastography (SWE) is a noninvasive ultrasound technique quantifying tissue stiffness, potentially reflecting tumor biology. The present study evaluated the role of SWE in predicting IHC profiles of breast cancers.

METHODS

A retrospective observational study was conducted over 6 months at a tertiary hospital. Thirty patients with histopathologically proven malignant breast lesions who underwent SWE were included. Elastographic parameters were correlated with IHC markers (estrogen receptor [ER], progesterone receptor [PR], HER2neu, and Ki-67). Statistical analyses included ANOVA, receiver operating characteristic (ROC) curve analysis, and logistic regression using the SPSS software version 30.0.

RESULTS

Mean patient age was 52 ± 10.7 years, with 80% patients presenting with ductal carcinoma. Hormone receptor-positive tumors exhibited significantly higher stiffness than negative ones (E max: P = 0.020 for ER, P = 0.011 for PR). Luminal A and B cancers showed higher E max (81.46 kPa) and E mean (47.33 kPa) than triple-negative breast cancers (TNBC) (E max 54.16 kPa, E mean 35.13 kPa). ROC analysis showed significant diagnostic abilities of SWE for TNBC (area under the curve [AUC] 0.783-0.789) and hormone-positive tumors (AUC 0.757-0.831). However, logistic regression revealed no independent predictive power of SWE parameters for IHC subtyping.

CONCLUSION

SWE demonstrates distinct stiffness profiles across breast cancer subtypes, with stiffer profiles for hormone receptor-positive tumors than triple-negative ones. While SWE offers adjunctive diagnostic value, it cannot currently replace histopathology for molecular characterization.