Determination of breast cancer prognosis after neoadjuvant chemotherapy: comparison of Residual Cancer Burden (RCB) and Neo-Bioscore

Abstract

Background To compare RCB (Residual Cancer Burden) and Neo-Bioscore in terms of prognostic performance and see if adding pathological variables improve these scores. Methods We analysed 750 female patients with invasive breast cancer (BC) treated with neoadjuvant chemotherapy (NAC) at Institut Curie between 2002 and 2012. Scores were compared in global population and by BC subtype using Akaike information criterion (AIC), C-Index (concordance index), calibration curves and after adding lymphovascular invasion (LVI) and pre-/post-NAC TILs levels. Results RCB and Neo-Bioscore were significantly associated to disease-free and overall survival in global population and for triple-negative BC. RCB had the lowest AICs in every BC subtype, corresponding to a better prognostic performance. In global population, C-Index values were poor for RCB (0.66; CI [0.61–0.71]) and fair for Neo-Bioscore (0.70; CI [0.65–0.75]). Scores were well calibrated in global population, but RCB yielded better prognostic performances in each BC subtype. Concordance between the two scores was poor. Adding LVI and TILs improved the performance of both scores. Conclusions Although RCB and Neo-Bioscore had similar prognostic performances, RCB showed better performance in BC subtypes, especially in luminal and TNBC. By generating fewer prognostic categories, RCB enables an easier use in everyday clinical practice.

Development, verification, and comparison of a risk stratification model integrating residual cancer burden to predict individual prognosis in early-stage breast cancer treated with neoadjuvant therapy

“…This is likely because of the distribution difference of heterogeneity in different races, the discrepancy of NAC therapeutic guidelines in different countries, and the predictive improvement of our model after including RCB and LVI. 16 , 17…”

“…AJCC stage, grade, ER expression, HER2 status and treatment, Ki-67 expression, and LVI have been determined as independent predictors in BC patients who received NAC. [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] T stage and N stage, which indicate primary and metastatic lymph node burden, respectively, have been seen as predictors in several studies. 15,18 The model we constructed incorporated AJCC stage, which takes together these two factors.…”

“…45 Recently, Laas et al reported that Neo-Bioscore had better performance in the overall population compared with RCB, but that RCB showed better performance in subtype-specific groups, especially for luminal BC and TNBC. 16 However, a study conducted by Dana-Farber Cancer Institute showed that RCB is superior to the Neo-Bioscore for stratifying patients into different survival outcomes. 17 Intriguingly, the AUROC values of five models applied to the patients in our center were inferior to those of the model.…”

“…[13][14][15] However, almost all these studies are seemly dated because human epidermal growth factor receptor 2 (HER2)-targeted therapies and informative pathological measurement were not taken into consideration in that case. [6][7][8][9][10][11][12]16,17 A nomogram created for the population in the recent clinical guidelines is therefore urgently required and comparisons of the novel model with previous models are crucial.…”

“…Basic and predictive parameters for formulating a model specific to patients with BC encompass clinical stage, histology type, grade, the expression of ER, progesterone receptor (PR), Ki-67, and HER2, residual tumor burden [including pathological complete remission (pCR) status, pathological AJCC stage], and lymphovascular invasion (LVI). [6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] Among these indicators, residual tumor appears especially important not only because it shows a negative correlation with prognosis but also its cancer burden ranges from single cancer cell to large diameters of tumor in these patients, which, in part, could lead to a great degree of heterogeneity in BC population after NAC. Several randomized studies and meta-analysis demonstrated that patients achieving pCR during the NAC have longer diseasefree survival (DFS) and overall survival (OS) than those with residual cancer.…”