Diagnostic performance of TILs–US score and LPBC in biopsy specimens for predicting pathological complete response in patients with breast cancer

Tumor-infiltrating lymphocytes–ultrasonography (TILs–US) score is used to predict lymphocyte-predominant breast cancer (LPBC) in surgical specimens. We aimed to compare diagnostic performance of TILs–US score for predicting pathological complete response (pCR) with that of LPBC in biopsy specimens.

TILs ≥ 50% in biopsy specimens was defined as biopsy–LPBC, and TILs–US score ≥ 4 was categorized as TILs–US score-high. Basic nomogram for pCR was developed using stepwise logistic regression based on the smallest Akaike Information Criterion, and biopsy–LPBC and TILs–US score nomograms were developed by integrating biopsy–LPBC or TILs–US scores into a basic nomogram. The diagnostic performance of the nomograms for pCR was compared using area under the curve (AUC), categorical net reclassification improvement (NRI), and integrated discrimination improvement (IDI).

This retrospective study evaluated 118 patients with breast cancer, including 33 (28.0%) with biopsy–LPBC, 52 (44.1%) with TILs–US score-high, with 34 (28.8%) achieving pCR. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and AUC for predicting pCR were 0.53, 0.82, 2.96, 0.57, and 0.68, respectively, for biopsy–LPBC, and 0.76, 0.69, 2.47, 0.34, and 0.73, respectively, for TILs–US score. The biopsy–LPBC nomogram showed significant improvements in categorical NRI (p = 0.023) and IDI (p = 0.007) but not in AUC (p = 0.25), compared with the basic nomogram. The TILs–US nomogram exhibited significant improvements in AUC (p = 0.039), categorical NRI (p = 0.010), and IDI (p < 0.001).

The TILs–US score may serve as a novel marker for prediction of pCR in patients with breast cancer. An external validation study is warranted to confirm our findings.