Nottingham Clinico-Pathological Response Index (NPRI) after Neoadjuvant Chemotherapy (Neo-ACT) Accurately Predicts Clinical Outcome in Locally Advanced Breast Cancer

A dedicated structured data set for reporting of invasive carcinoma of the breast in the setting of neoadjuvant therapy: recommendations from the International Collaboration on Cancer Reporting (ICCR)

AIMS

The International Collaboration on Cancer Reporting (ICCR), a global alliance of major (inter-)national pathology and cancer organisations, is an initiative aimed at providing a unified international approach to reporting cancer. ICCR recently published new data sets for the reporting of invasive breast carcinoma, surgically removed lymph nodes for breast tumours and ductal carcinoma in situ, variants of lobular carcinoma in situ and low-grade lesions. The data set in this paper addresses the neoadjuvant setting. The aim is to promote high-quality, standardised reporting of tumour response and residual disease after neoadjuvant treatment that can be used for subsequent management decisions for each patient.

METHODS

The ICCR convened expert panels of breast pathologists with a representative surgeon and oncologist to critically review and discuss current evidence. Feedback from the international public consultation was critical in the development of this data set.

RESULTS

The expert panel concluded that a dedicated data set was required for reporting of breast specimens post-neoadjuvant therapy with inclusion of data elements specific to the neoadjuvant setting as core or non-core elements. This data set proposes a practical approach for handling and reporting breast resection specimens following neoadjuvant therapy. The comments for each data element clarify terminology, discuss available evidence and highlight areas with limited evidence that need further study. This data set overlaps with, and should be used in conjunction with, the data sets for the reporting of invasive breast carcinoma and surgically removed lymph nodes from patients with breast tumours, as appropriate. Key issues specific to the neoadjuvant setting are included in this paper. The entire data set is freely available on the ICCR website.

CONCLUSIONS

High-quality, standardised reporting of tumour response and residual disease after neoadjuvant treatment are critical for subsequent management decisions for each patient.

Pathology of neoadjuvant therapy and immunotherapy testing for breast cancer

Neoadjuvant chemotherapy (NACT) has become the standard of care for high-risk breast cancer, including triple-negative (TNBC) and HER2-positive disease. As a result, handling and reporting of breast specimens post-NACT is part of routine practice, and it is important for pathologists to recognise the changes in tumour cells, tumour-associated stroma and background breast tissue induced by NACT. Familiarity with characteristic stromal features enables identification of the pre-treatment tumour site and allows confident diagnosis of pathological complete response (pCR) which is important for decisions concerning adjuvant therapy. Neoadjuvant endocrine therapy (NAET) is used less frequently than NACT; however, the SARS-COVID-19 pandemic has changed practice, with increased use as bridging therapy if surgery is delayed. NAET also induces characteristic changes in the tumour and stroma. Changes in the tumour microenvironment following NACT and NAET are also described. Immunotherapy is approved for use in advanced TNBC, and there are several trials exploring its role in early TNBC in the neoadjuvant setting. The current biomarker to determine eligibility for treatment with immune checkpoint inhibitors is programmed death ligand-1 (PD-L1) immunohistochemistry; however, this is complicated by lack of standardisation with different drugs linked to tests using different antibodies with different scoring systems. The situation in the neoadjuvant setting is further complicated by improved pCR rates for PD-L1-positive tumours in both immune therapy and placebo arms. Alternative biomarkers are urgently needed to identify which patients will derive benefit from immunotherapy and key candidates are discussed.

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

Background

A favorable model for predicting disease-free survival (DFS) and stratifying prognostic risk in breast cancer (BC) treated with neoadjuvant chemotherapy (NAC) is lacking. The aim of the current study was to formulate an excellent model specially for predicting prognosis in these patients.

Patients and methods

Between January 2012 and December 2015, 749 early-stage BC patients who received NAC in Xijing hospital were included. Patients were randomly assigned to a training cohort (n = 563) and an independent cohort (n = 186). A prognostic model was created and subsequently validated. Predictive performance and discrimination were further measured and compared with other models.

Results

Clinical American Joint Committee on Cancer stage, grade, estrogen receptor expression, human epidermal growth factor receptor 2 (HER2) status and treatment, Ki-67 expression, lymphovascular invasion, and residual cancer burden were identified as independent prognostic variables for BC treated with NAC. The C-index of the model consistently outperformed other available models as well as single independent factors with 0.78, 0.80, 0.75, 0.82, and 0.77 in the training cohort, independent cohort, luminal BC, HER2-positive BC, and triple-negative BC, respectively. With the optimal cut-off values (280 and 360) selected by X-tile, patients were categorized as low-risk (total points ≤280), moderate-risk (280 < total points ≤ 360), and high-risk (total points >360) groups presenting significantly different 5-year DFS of 89.9%, 56.9%, and 27.7%, respectively.

Conclusions

In patients with BC, the first model including residual cancer burden index was demonstrated to predict the survival of individuals with favorable performance and discrimination. Furthermore, the risk stratification generated by it could determine the risk level of recurrence in whole early-stage BC cohort and subtype-specific cohorts, help tailor personalized intensive treatment, and select comparable study cohort in clinical trials.

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Establishing the first risk stratification nomogram for BC treated with NAC and validate its performance in BC cohorts.

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Incorporating residual cancer burden index into predictive nomogram for the first time.

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Predictive model can be utilized to predict DFS for all early-stage BC treated with NAC.

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Performing a continuous rather than categorized model to predict individual survival.

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The risk stratification can be used to select comparable population in trial design.

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

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.

Predictors of Pathological Complete Response to Neoadjuvant Chemotherapy in Iranian Breast Cancer Patients

Background:

Achievement of pathologic complete response (pCR) in breast cancer patients receiving neoadjuvant chemotherapy (NAC) is associated with both overall survival and disease-free survival. The aim of present study was to identify clinical and pathological factors associated with achieving pCR in Iranian breast cancer patients receiving NAC.

Methods:

A retrospective review of all breast cancer patients treated with neoadjuvant chemotherapy between April 2012 and September 2016 at our institution was performed; 207 cases were evaluable for analysis. pCR was defined as having no residual invasive tumor in the breast surgical specimen removed following neoadjuvant therapy.

Results:

In univariate analysis, factors associated with pCR were age less than 35 years (p = 0.03), absence of Lymphovascular invasion (LVI) (p = 0.002) and negative hormone receptor status (p = 0.003). Hormone receptor status (P = 0.01; OR, 2.45; CI, 1.20 - 4.99) and LVI (P = 0.001; OR, 0.22; CI, 0.10 - 0.46) remained predictive variables in multivariate analysis after correction for the other variables.

Conclusions:

In conclusion, the results of this study suggests that presence of Lymphovascular invasion and positive hormone receptor status are associated with poorer response to neoadjuvant chemotherapy in breast cancer patients.

Lymphovascular invasion after neoadjuvant chemotherapy is strongly associated with poor prognosis in breast carcinoma

PURPOSE

Few studies evaluated the prognostic value of the presence of lymphovascular invasion (LVI) after neoadjuvant chemotherapy (NAC) for breast cancer (BC).

METHODS

The association between LVI and survival was evaluated in a cohort of BC patients treated by NAC between 2002 and 2011. Five post-NAC prognostic scores (ypAJCC, RCB, CPS, CPS + EG and Neo-Bioscore) were evaluated and compared with or without the addition of LVI.

RESULTS

Out of 1033 tumors, LVI was present on surgical specimens in 29.2% and absent in 70.8% of the cases. Post-NAC LVI was associated with impaired disease-free survival (DFS) (HR 2.54; 95% CI 1.96-3.31; P < 0.001), and the magnitude of this effect depended on BC subtype (P_interaction = 0.003), (luminal BC: HR 1.83; P = 0.003; triple negative BC: HR 3.73; P < 0.001; HER2-positive BC: HR 6.21; P < 0.001). Post-NAC LVI was an independent predictor of local relapse, distant metastasis, and overall survival; and increased the accuracy of all five post-NAC prognostic scoring systems.

CONCLUSIONS

Post-NAC LVI is a strong independent prognostic factor that: (i) should be systematically reported in pathology reports; (ii) should be used as stratification factor after NAC to propose inclusion in second-line trials or adjuvant treatment; (iii) should be included in post-NAC scoring systems.

An audit of residual cancer burden reproducibility in a UK context

AIMS

The residual cancer burden score (RCB) is currently the preferred quantification tool for assessing residual disease following neoadjuvant chemotherapy (NACT) in breast cancer clinical trials. This has been shown to be highly reproducible at the MD Anderson Cancer Centre, where it was developed originally. We wanted to evaluate RCB in a UK context, where macroscopic handling of tissue may differ between sites.

METHODS AND RESULTS

The pathology slides from 90 post-NACT patients from Guy's and St Thomas' NHS Foundation Trust and the Royal Bournemouth Hospital were reviewed independently by two specialist breast histopathologists who recalculated the RCB for each case. Data were collated and analysed statistically for interobserver reproducibility, for both numerical and categorical RCB. Overall, agreement between pathologists was 'good' [kappa = 0.775; 95% confidence interval (CI) = 0.668-0.882]. The overall concordance for continuous RCB score and for categorical RCB group was statistically significant (Spearman's correlation coefficient = 0.9497; 95% CI = 0.9235-0.9671; P < 0.0001 and Spearman's correlation coefficient = 0.9145; 95% CI = 0.8712-0.9437; P < 0.0001, respectively). Discordance could not be attributed to any one component of the RCB calculation.

CONCLUSIONS

These data suggest that the RCB score is reproducible in a UK context. Further data comparing it to other quantification systems is required, however, before any superiority can be established.

Lymphovascular invasion is an independent predictor of survival in breast cancer after neoadjuvant chemotherapy

Various prognostic indicators have been investigated in neoadjuvant chemotherapy (NAC)-treated invasive breast cancer (BC). Our study examines if lymphovascular invasion (LVI) is an independent predictor of survival in women receiving NAC. We performed a retrospective analysis in 166 women with operable invasive BC who underwent adriamycin- and taxane-based NAC between 2000 and 2013. The presence of LVI was noted in breast excisions following NAC. Associations between progression-free and overall survival and LVI and other clinicopathologic variables were assessed. Median follow-up was 31 months (range 1.4-153 months) with a total of 56 events and 24 deaths from any cause. LVI was found in 74 of 166 patients (45 %). In univariate analysis, the presence of LVI was associated with worse progression-free survival (HR 3.37, 95 % CI 1.87-6.06, p < 0.01) and overall survival (HR 4.35, 95 % CI 1.61-11.79, p < 0.01). In multivariate models adjusting for breast cancer subtype, LVI was significantly associated with a decrease in progression-free survival (HR 3.76, 95 % CI 2.07-6.83, p < 0.01) and overall survival (HR 5.70, 95 % CI 2.08-15.64, p < 0.01). When stratified by subtype, those with hormone receptor or HER2-positive BCs with no LVI had the most favorable progression-free and overall survival. Those with both LVI and triple-negative BC had the worst progression-free and overall survival. LVI is an important prognostic marker and is associated with worse clinical outcome in breast cancer patients receiving NAC.

The prognostic value of the neoadjuvant response index in triple-negative breast cancer: validation and comparison with pathological complete response as outcome measure

The Neoadjuvant response index (NRI) has been proposed as a simple measure of downstaging by neoadjuvant treatment in breast cancer. It was previously found to predict recurrence-free survival (RFS) in triple-negative (TN) breast cancer. It was at least as accurate as the standard binary system, the absence or presence of a pathological complete remission (pCR), which is the commonly employed outcome measure. The NRI was evaluated in an independent consecutive series of patients to validate the previous findings. Univariable and multivariable analyses were done to assess the predictive value of clinical parameters and of the NRI for RFS. We combined the original and validation series of patients to build a multivariable predictive model for RFS after neoadjuvant chemotherapy in TN breast cancer. The validation set (N = 108) confirmed that patients with a higher-than-median NRI (>0.7) had excellent RFS (P = 0.002), similar to that of patients who had achieved a pCR. Multivariable analysis in 191 patients showed that the NRI was a strong independent predictor of RFS (P = 0.0002), with N-stage (P = 0.001) and T-stage (P = 0.014) ranking second and third, respectively. Importantly, among patients who did not achieve a pCR (NRI values below 1), higher NRI values were still associated with better RFS. The NRI is a simple method and a practical tool to predict RFS in TN breast cancer patients treated with neoadjuvant chemotherapy. It adds prognostic information to the presence or absence of pCR and could be useful to compare the efficacies of different chemotherapy regimens.