Pre-treatment hormonal receptor status and Ki67 index predict pathologic complete response to neoadjuvant trastuzumab/taxanes but not disease-free survival in HER2-positive breast cancer patients

Exploring the effectiveness of molecular subtypes, biomarkers, and genetic variations as first-line treatment predictors in Asian breast cancer patients: a systematic review and meta-analysis

BACKGROUND

Breast cancer incidence has been on the rise significantly in the Asian population, occurring at an earlier age and a later stage. The potential predictive value of molecular subtypes, biomarkers, and genetic variations has not been deeply explored in the Asian population. This study evaluated the effect of molecular subtype classification and the presence or absence of biomarkers and genetic variations on pathological complete response (pCR) after neoadjuvant treatment in Asian breast cancer patients.

METHODS

A systematic search was conducted in MEDLINE (PubMed), Science Direct, Scopus, and Cochrane Library databases. Studies were selected if they included Asian breast cancer patients treated with neoadjuvant chemotherapy and contained data for qualitative or quantitative analyses. The quality of the included studies was assessed using the Newcastle Ottawa Scale. Following the random effects model, pooled odds ratios or hazard ratios with 95% confidence intervals for pCR were analysed using Review Manager Software. Heterogeneity between studies was assessed using Cochran's Q-test and I2 test statistics.

RESULTS

In total, 19,708 Asian breast cancer patients were pooled from 101 studies. In the neoadjuvant setting, taxane-anthracycline (TA) chemotherapy showed better pCR outcomes in triple-negative breast cancer (TNBC) (p<0.0001) and human epidermal growth factor receptor 2 enriched (HER2E) (p<0.0001) than luminal breast cancer patients. Similarly, taxane-platinum (TP) chemotherapy also showed better pCR outcomes in TNBC (p<0.0001) and HER2E (p<0.0001). Oestrogen receptor (ER)-negative, progesterone receptor (PR)-negative, HER2-positive and high Ki-67 were significantly associated with better pCR outcomes when treated with either TA or TP. Asian breast cancer patients harbouring wildtype PIK3CA were significantly associated with better pCR outcomes when treated with TA in the neoadjuvant setting (p=0.001).

CONCLUSIONS

In the neoadjuvant setting, molecular subtypes (HER2E and TNBC), biomarkers (ER, PR, HER2, HR, Ki-67, nm23-H1, CK5/6, and Tau), and gene (PIK3CA) are associated with increased pCR rates in Asian breast cancer patients. Hence, they could be further explored for their possible role in first-line treatment response, which can be utilised to treat breast cancer more efficiently in the Asian population. However, it needs to be further validated with additional powered studies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42021246295.

A Review of Trastuzumab Biosimilars in Early Breast Cancer and Real World Outcomes of Neoadjuvant MYL-1401O versus Reference Trastuzumab

The reduced cost of trastuzumab biosimilars has led to increased adoption for HER2-positive breast cancer. This review of trastuzumab biosimilars encompasses this development and real world clinical data in early breast cancer. In addition, we present a retrospective study evaluating the total pathological complete response (tpCR) rates (lack of residual invasive cancer in resected breast tissue and axillary nodes), of MYL-1401O to reference trastuzumab (TRZ) in the neoadjuvant setting for HER2+ early breast cancer (EBC) in Alberta, Canada. Neoadjuvant patients with HER2+ EBC treated with TRZ from November 2018–October 2019 and MYL-1401O from December 2019–September 2020 were identified. Logistic regression was used to control for variables potentially associated with tpCR: trastuzumab product, age, pre-operative T- and N-stage, grade, hormone receptor (HR)-status, HER2-status, chemotherapy regimen, and chemotherapy completion. tpCR was 35.6% in the MYL-1401O group (n = 59) and 40.3% in the TRZ (n = 77) group, p = 0.598. After controlling for clinically relevant variables, there was no significant difference in the odds of achieving tpCR in patients treated with TRZ versus MYL-1401O (OR 1.1, 95% CI 0.5–2.4, p = 0.850). tpCR rates were similar for patients treated with MYL-1401O compared to trastuzumab in our real world study of HER2+ neoadjuvant EBC and comparable to pivotal phase 3 trials.

Comparing Biomarkers for Predicting Pathological Responses to Neoadjuvant Therapy in HER2-Positive Breast Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

The predictive strength and accuracy of some biomarkers for the pathological complete response (pCR) to neoadjuvant therapy for HER2-positive breast cancer remain unclear. This study aimed to compare the accuracy of the HER2-enriched subtype and the presence of PIK3CA mutations, namely, TILs, HRs, and Ki-67, in predicting the pCR to HER2-positive breast cancer therapy.

METHODS

We screened studies that included pCR predicted by one of the following biomarkers: the HER2-enriched subtype and the presence of PIK3CA mutations, TILs, HRs, or Ki-67. We then calculated the pooled sensitivity, specificity, positive and negative predictive values (PPVs and NPVs, respectively), and positive and negative likelihood ratios (LRs). Summary receiver operating characteristic (SROC) curves and areas under the curve (AUCs) were used to estimate the diagnostic accuracy.

RESULTS

The pooled estimates of sensitivity and specificity for the HER2-enriched subtype and the presence of PIK3CA mutations, namely, TILs, HRs, and Ki-67, were 0.66 and 0.62, 0.85 and 0.27, 0.49 and 0.61, 0.54 and 0.64, and 0.68 and 0.51, respectively. The AUC of the HER2-enriched subtype was significantly higher (0.71) than those for the presence of TILs (0.59, p = 0.003), HRs (0.65, p = 0.003), and Ki-67 (0.62, p = 0.005). The AUC of the HER2-enriched subtype had a tendency to be higher than that of the presence of PIK3CA mutations (0.58, p = 0.220). Moreover, it had relatively high PPV (0.58) and LR+ (1.77), similar NPV (0.73), and low LR- (0.54) compared with the other four biomarkers.

CONCLUSIONS

The HER2-enriched subtype has a moderate breast cancer diagnostic accuracy, which is better than those of the presence of PIK3CA mutations, TILs, HRs, and Ki-67.

Pathologic Complete Response after Neoadjuvant Chemotherapy and Impact on Breast Cancer Recurrence and Survival: A Comprehensive Meta-analysis

PURPOSE

While various studies have highlighted the prognostic significance of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAT), the impact of additional adjuvant therapy after pCR is not known.

EXPERIMENTAL DESIGN

PubMed was searched for studies with NAT for breast cancer and individual patient-level data was extracted for analysis using plot digitizer software. HRs, with 95% probability intervals (PI), measuring the association between pCR and overall survival (OS) or event-free survival (EFS), were estimated using Bayesian piece-wise exponential proportional hazards hierarchical models including pCR as predictor.

RESULTS

Overall, 52 of 3,209 publications met inclusion criteria, totaling 27,895 patients. Patients with a pCR after NAT had significantly better EFS (HR = 0.31; 95% PI, 0.24-0.39), particularly for triple-negative (HR = 0.18; 95% PI, 0.10-0.31) and HER2+ (HR = 0.32; 95% PI, 0.21-0.47) disease. Similarly, pCR after NAT was also associated with improved survival (HR = 0.22; 95% PI, 0.15-0.30). The association of pCR with improved EFS was similar among patients who received subsequent adjuvant chemotherapy (HR = 0.36; 95% PI, 0.19-0.67) and those without adjuvant chemotherapy (HR = 0.36; 95% PI, 0.27-0.54), with no significant difference between the two groups (P = 0.60).

CONCLUSIONS

Achieving pCR following NAT is associated with significantly better EFS and OS, particularly for triple-negative and HER2+ breast cancer. The similar outcomes with or without adjuvant chemotherapy in patients who attain pCR likely reflects tumor biology and systemic clearance of micrometastatic disease, highlighting the potential of escalation/deescalation strategies in the adjuvant setting based on neoadjuvant response.See related commentary by Esserman, p. 2771.

Hormone receptor-negative as a predictive factor for pathologic complete response to neoadjuvant therapy in breast cancer

OBJECTIVE

To define a predictive factor for pathologic complete response, compare the oncologic outcomes associated with the degree of pathologic response after neoadjuvant chemotherapy, and to analyze pathologic complete response as a prognostic factor for overall survival and progression-free survival.

METHODS

A retrospective study of patients admitted to Hospital Estadual Mário Covas and Hospital Anchieta from 2008 to 2012, with locally advanced breast cancer. Hormone receptor status, HER2 status, histologic and nuclear grade, age upon diagnosis and histological type of the tumor were analyzed. Pathologic evaluation of the tumor was subdivided into pathologic complete response, defined by the absence of tumor; intermediate response, considered as a favorable stage; and poor response, considering low-responder patients. Data obtained were submitted to statistical analysis.

RESULTS

The study included 243 patients. There was an association of pathologic complete response with HER-2 negative, histological grade 3, stage III, hormone receptor negative, positive lymph node, older age and more advanced tumors. However, after multivariate analysis the only predictor of pathologic complete response was the presence of negative hormone receptor. By analyzing the prognostic factors, hormone receptor negative was considered as an independent risk factor, and pathologic complete response was considered as an independent protective factor.

CONCLUSION

Hormone receptor negative is predictive of pathologic complete response and is an isolated risk factor for lower progression-free survival and overall survival. Pathologic complete response is a protective factor for these same survival analyses.

Ki-67 labeling index is a predictive marker for a pathological complete response to neoadjuvant chemotherapy in breast cancer: A meta-analysis

BACKGROUND

A pathological complete response (pCR) after neoadjuvant chemotherapy (NCT) is a strong indicator of the benefit of therapy and presents an early surrogate for a favorable long-term outcome. It remains unclear whether Ki-67, a marker for tumor proliferation, can function as a predictor of the response to NCT in breast cancer. The objective of this meta-analysis was to compare the pCR rate and clinical outcomes in breast cancer patients with different Ki-67 labeling indexes (Ki-67 LI) who received NCT.

METHODS

Clinical studies were retrieved from the electronic databases of PubMed, Embase, Clinical Trials, Wanfang, and the Chinese National Knowledge Infrastructure, from their inception to July 31, 2017. Meta-analysis was performed on pool eligible studies to determine whether Ki-67 LI was associated with the pCR rate and clinical outcomes of breast cancer patients who were treated with NCT. Pooled analyses were performed using fixed effects models. Two reviewers screened all titles and abstracts and independently assessed all articles.

RESULTS

A total of 36 studies involving 6793 patients were included in the meta-analysis. Pooled analysis results revealed that patients with high Ki-67 LI exhibited significantly higher pCR rates (odds ratio [OR] = 3.94, 95% confidence interval [CI]: 3.33-4.67, P <.001) but poorer relapse-free survival (OR = 1.99, 95% CI: 1.39-2.85, P <.001) than those with low Ki-67 LI, but there was no significant difference in objective tumor response rate.

CONCLUSION

The meta-analysis reported here demonstrates that pretherapeutic Ki-67 LI is associated with pCR in breast cancer patients undergoing NCT. More phase III randomized clinical trials will be required to confirm our findings.

Predictive factors of pathologic complete response in HER2-positive and axillary lymph node positive breast cancer after neoadjuvant paclitaxel, carboplatin plus with trastuzumab

OBJECTIVE

This study was performed to investigate the proportion as well as the predictive factors of pathologic complete response in HER2-positive and axillary lymph node positive breast cancer after neoadjuvant paclitaxel, carboplatin plus with trastuzumab (PCH).

RESULTS

The pCR rate in the breast, axilla and both was 44.3% (39/88), 47.7% (42/88) and 34.1% (30/88), respectively. Patients with and without pCR were similar in term of age, BMI, menstrual status, family history, treatment cycles and tumor characteristics (laterality and size of tumor). Multivariate logistic regression demonstrated that pCR was significantly associated with HR negativity (HR = 5.587, 95% CI 2.25-3.889, p < 0.001), high Ki67 index (HR = 4.130, 95% CI 1.607-10.610, p = 0.003). Further investigation found that patients with HR-negative/high Ki67 index had higher pCR rate, compared to other patients (HR = 7.583, 95% CI 2.503-22.974, p < 0.001).

MATERIALS AND METHODS

88 consecutive Chinese HER2-positive/axillary lymph node-positive breast cancer patients with neodjuvant therapy regimen containing paclitaxel, carboplatin and trastuzumab were divided into two groups: pathological complete response (pCR) or non-pCR group. Clinico-pathological characteristics were compared and analyzed, and univariate and multivariate analyses were performed to detect the predictive factors of pCR.

CONCLUSIONS

Preoperative PCH regimen was an effective neoadjuvant therapy in HER2 positive and axillary lymph node positive patients, and patients coexisting with HR-negative and high Ki67 index may benefit more from this regimen.

Prognostic values of Ki-67 in neoadjuvant setting for breast cancer: a systematic review and meta-analysis

AIM

To assess the prognostic values of Ki-67 in neoadjuvant setting for breast cancer patients.

METHODS

PubMed and EMBASE were searched. Revman software was used to conduct random-effect model meta-analysis.

RESULTS

49 studies (14,076 patients) were included. High Ki-67 before and after neoadjuvant chemotherapy were associated with worse overall survival (OS; before: hazard ratio [HR]: 2.29; 95% CI: 1.42-3.69; after: HR: 2.24; 95% CI: 1.82-2.75) and disease-free survival (DFS; before: HR: 1.54; 95% CI: 1.23-1.95; after: HR: 2.08; 95% CI: 1.83-2.37). Low/no reduction or increase might be associated with worse DFS (HR: 2.13; 95% CI: 1.51-3.02) and OS.

CONCLUSION

Ki-67 before and after neoadjuvant chemotherapy, as well as the change could predict the prognosis for breast cancer patients.

The predictive value of Ki-67 before neoadjuvant chemotherapy for breast cancer: a systematic review and meta-analysis

AIM

To review the predictive values of Ki-67 before neoadjuvant chemotherapy (NAC) for breast cancer patients.

METHODS

PubMed and EMBASE were searched. Random-effect model meta-analysis was conducted using Revman software.

RESULTS

High Ki-67 was associated with more pathological complete responses (pCRs) events (odds ratio: 3.10; 95% CI: 2.52-3.81; 53 studies, 10,848 patients) regardless of HR⁺, HER2⁺ and triple-negative breast cancer types, the definitions of pCR and cut-off points for Ki-67. Ki-67 could predict pCR in those who received anthracyclines plus taxanes, and anthracyclines only, and those from Asia and Europe.

CONCLUSION

High Ki-67 before NAC was a predictor for pCR in neoadjuvant setting for breast cancer patients.

Combination of shear wave elastography and Ki-67 index as a novel predictive modality for the pathological response to neoadjuvant chemotherapy in patients with invasive breast cancer

PURPOSE

This study evaluated shear wave elastography (SWE) and SWE combined with the Ki-67 index as novel predictive modalities for the pathological response of invasive breast cancer to neoadjuvant chemotherapy (NAC).

METHODS

The prospective study recruited 66 eligible patients from July 2014 to November 2015. Tumour stiffness, which corresponds with tumour progression and invasiveness, was assessed by quantitative SWE 1 d before biopsy (time point t0, elasticity E0), 1 d before next NAC cycle (t1-t5, E1-E5), and 1 d before surgery (t6, E6). The relative changes in SWE parameters after the first and second NAC cycles were considered as the variables [ΔE (t1), ΔE (t2)]. The pathological response was classified according to the residual cancer burden (RCB) protocol. Correlations between RCB scores and variables were evaluated. The predictive diagnostic performances of SWE parameters, Ki-67 index, and the predictive RCB (predRCB) score determined by a linear regression model were compared.

RESULTS

Some immunohistochemical and molecular factors and SWE parameters were significantly different among the three RCB groups. The ΔE_mean (t2) and Ki-67 had significantly better diagnostic performance than other parameters regarding predicting the pathological response (the RCB-I response and RCB-III resistance). However, the correlation between ΔE_mean (t2) and Ki-67 index was significantly weaker as a diagnostic predictor (r = 0.29). We generated a new predictive modality, predRCB, which is a multivariable linear regression model that combines ΔE_mean (t2) and the Ki-67 index. The predRCB modality showed better diagnostic performance than SWE parameters and Ki-67 index alone.

CONCLUSION

Our findings highlight the potential utility for adding the Ki-67 index to the SWE results, which may improve the predictive power of SWE and facilitate personalising the treatment regimens of patients with breast cancer. These results should be validated in the future by performing a multicentre prospective study with a larger cohort.

Associations between sociodemographic and clinicopathological factors and breast cancer subtypes in a population-based study

PURPOSE

This study examines the factors distinguishing breast cancer (BC) subtypes.

METHODS

We examined subtypes in 629 women with invasive BC, diagnosed from 2006 to 2012, and enrolled in an epidemiological study in New Jersey. Using molecular characteristics from pathology reports, BCs were categorized as luminal A, luminal B, non-luminal HER2-expressing, or triple-negative breast cancer (TNBC) subtypes. Multinomial logistic models (luminal A as referent) were used to describe BC subtype associations.

RESULTS

Women with luminal B tumors were more likely to be younger at diagnosis [odds ratio (OR) 1.8, 95% confidence interval (CI) 1.0-3.4] and to have higher-grade (OR 2.6, 95% CI 1.5-4.7), larger (OR 1.9, 95% CI 1.0-3.6), and Ki67-positive tumors (OR 2.1, 95% CI 1.1-4.0). Women with non-luminal HER2-expressing BCs were more likely to have higher-grade tumors (OR 14.5, 95% CI 5.3-39.7). Women with TNBCs were more likely to be African-American (OR 1.9, 95% CI 1.0-3.4) and to have higher-grade (OR 9.7, 95% CI 5.1-18.4), larger (OR 2.2, 95% CI 1.0-4.8), and Ki67-positive (OR 2.9, 95% CI 1.6-5.2) tumors. Notably, compared to the luminal A subtype, luminal B, non-luminal HER2-expressing, and triple-negative subtypes were more frequently self-detected; however, these associations were attenuated in multivariable models.

CONCLUSIONS

These findings suggest that some BC subtypes were associated with features denoting more aggressive phenotypes, namely higher grade, larger size, and Ki67 positivity, and possibly patient self-detection among some women. These findings highlight a need for enhanced screening, particularly among younger women, racial/ethnic minorities, and lower socioeconomic subgroups.

Randomized trial of preoperative docetaxel with or without capecitabine after 4 cycles of 5-fluorouracil– epirubicin–cyclophosphamide (FEC) in early-stage breast cancer: exploratory analyses identify Ki67 as a predictive biomarker for response to neoadjuvant chemotherapy

This randomized, multicenter study compared the efficacy of docetaxel with or without capecitabine following fluorouracil/epirubicin/cyclophosphamide (FEC) therapy in operable breast cancer and investigated the role of Ki67 as a predictive biomarker. Patients were randomized to 4 cycles of docetaxel/capecitabine (docetaxel: 75 mg/m² on day 1; capecitabine: 1,650 mg/m² on days 1–14 every 3 weeks) or docetaxel alone (75 mg/m² on day 1 every 3 weeks) after completion of 4 cycles of FEC (5-fluorouracil 500 mg/m², epirubicin 100 mg/m² and cyclophosphamide 500 mg/m² on day 1 every 3 weeks). The primary endpoint was the pathological complete response (pCR) rate. Predictive factor analysis was conducted using clinicopathological markers, including hormone receptors and Ki67 labeling index (Ki67LI). A total of 477 patients were randomized; the overall response in the docetaxel/capecitabine and docetaxel groups was 88.3 and 87.4 %, respectively. There were no significant differences in the pCR rate (docetaxel/capecitabine: 23 %; docetaxel: 24 %; p = 0.748), disease-free survival, or overall survival. However, patients with mid-range Ki67LI (10–20 %) showed a trend towards improved pCR rate with docetaxel/capecitabine compared to docetaxel alone. Furthermore, multivariate logistic regression analysis showed pre-treatment Ki67LI (odds ratio 1.031; 95 % CI 1.014–1.048; p = 0.0004) to be a significant predictor of pCR in this neoadjuvant treatment setting. Docetaxel/capecitabine (after 4 cycles of FEC) did not generate significant improvement in pCR compared to docetaxel alone. However, exploratory analyses suggested that assessment of pre-treatment Ki67LI may be a useful tool in the identification of responders to preoperative docetaxel/capecitabine in early-stage breast cancer.

Female gender may predict response to FOLFIRINOX in patients with unresectable pancreatic cancer: a single institution retrospective review

FOLFIRINOX is a highly active regimen for the treatment of patients with unresectable pancreatic cancer. However, treatment with FOLFIRINOX is associated with relevant toxicity and predictors for response to therapy are warranted. We retrospectively analyzed 49 patients with unresectable pancreatic cancer treated with FOLFIRINOX in order to evaluate a possible predictive role of clinical parameters and tumor characteristics for response to chemotherapy. Tumor samples were characterized histopathologically before treatment and expression of p53 and Ki67 was analyzed using automated immunohistochemistry. Overall survival (OS) and progression-free survival (PFS) were estimated by the Kaplan-Meier method. The overall objective response rate was 55.1%, the disease control rate was 70.6%. Female gender was associated with a significantly higher disease control rate of 91.7 compared to 48.0% in male patients (p=0.001) which reached 100% in female patients when primarily treated compared to treatment after surgical resection and relapse (77.8%, p=0.057). For all patients median PFS was 3.5 months (95% CI, 2.7-4.3 months) and median OS was 13 months (95% CI, 9.4-16.6 months). Female patients showed a tendency towards a longer median PFS (5.0 months, 95% CI, 3.6-6.4 months) compared to males (3.0 months, 95% CI, 2.4-3.6 months) (p=0.099). Serum levels of CA19.9 and CEA were significantly higher in female patients compared to male patients (p=0.037, p=0.05). Tumors of patients with response to FOLFIRINOX showed a higher expression level of p53 and Ki67 as well as higher serum levels of CA19.9 compared to non-responders, which was statistically not significant. Our study indicates that female gender is a positive predictor for therapy response to FOLFIRINOX in patients with unresectable pancreatic cancer. Female gender in turn was associated with increased levels of tumor markers CEA and CA19.9 and patients with higher serum levels of CA19.9 were more responsive to FOLFIRINOX.

Axillary lymph node status, adjusted for pathologic complete response in breast and axilla after neoadjuvant chemotherapy, predicts differential disease-free survival in breast cancer

BACKGROUND

Our retrospective study in breast cancer patients evaluated whether integrating subtype and pathologic complete response (pcr) information into axillary lymph node restaging after neoadjuvant chemotherapy (nac) adds significance to its prognostic values.

METHODS

Patients included in the analysis had stage ii or iii disease, with post-nac axillary lymph node dissection (alnd), without sentinel lymph node biopsy before completion of nac, with definitive subtyping data and subtype-oriented adjuvant treatments. The ypN grading system was used to restage axillary lymph node status, and ypN0 was adjusted by pcr in both breast and axilla into ypN0(pcr) and ypN0(non-pcr). Univariate and multivariate survival analyses were performed.

RESULTS

Among the 301 patients analyzed, 145 had tumours that were hormone receptor-positive (hr+) and negative for the human epidermal growth factor receptor (her2-), 101 had tumours that were positive for her2 (her2+), and 55 had tumours that were triple-negative. The rate of pcr in both breast and axilla was 11.7%, 43.6%, and 25.5% respectively for the 3 subtypes. Compared with the non-pcr patients, the pcr patients had better disease-free survival (dfs) and overall survival (os): p = 0.002 for dfs and p = 0.011 for os. In non-pcr patients, dfs and os were similar in the ypN0(non-pcr) and ypN1 subgroups, and in the ypN2 and ypN3 subgroups. We therefore grouped the ypN grading results into ypN0(pcr) (n = 75), ypN0- 1(non-pcr) (n = 175), and ypN2-3 (n = 51). In those groups, the 3-year dfs was 98%, 91%, and 56%, and the 3-year os was 100%, 91%, and 82% respectively. The differences in dfs and os between those three subgroups were significant (all p < 0.05 in paired comparisons). Multivariate Cox regression showed that subtype and ypN staging adjusted by pcr were the only two independent factors predicting dfs.

CONCLUSIONS

Axillary lymph node status after nac, adjusted for pcr in breast and axilla, predicts differential dfs in patients without prior sentinel lymph node biopsy.