Outcome after neoadjuvant chemotherapy in Asian 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.

Illuminating the breast cancer survival rates among Southeast Asian women: A systematic review and meta-analysis spanning four decades

In Southeast Asia, breast cancer is the most prevalent cancer among women and ranks as the second leading cause of cancer-related deaths. This systematic review and meta-analysis, encompassing 27 observational cohort studies with a minimum one-year follow-up period, aimed to examine temporal trends in breast cancer survival rates. Among the subset of five out of eleven Southeast Asian nations with available data, our analysis revealed pooled survival rates of 88.8 % at 1 year, 73.8 % at 3 years, 70.8 % at 5 years, and 49.3 % at 10 years for breast cancer patients. The mean age at diagnosis was 50.77±10.07 years, with 52.81 % of patients presenting with positive lymph nodes. Notably, stages I and II remained predominant even five years post-diagnosis. Although an overall amelioration in survival rates transpired over the preceding four decades, a noticeable exception pertained to the 3-year rate, demonstrating limited improvement. These findings underscore the pressing need for enhanced research efforts, particularly in countries within the region that lack survival data, to enable accurate estimations. Furthermore, our review also emphasizes the crucial need for future comprehensive, well-designed studies to delve into the factors behind survival rate disparities in Southeast Asia and the younger age at diagnosis compared to other regions.

Invited commentary on "Neoadjuvant pertuzumab plus trastuzumab in combination with anthracycline-free chemotherapy regimen in patients with HER2 positive breast cancer: Real-world data from a single center in India"

The article "Neoadjuvant pertuzumab plus trastuzumab in combination with anthracycline-free chemotherapy regimen in patients with HER2 positive breast cancer: Real-world data from a single center in India" have presented the experience of neoadjuvant DCPH in Indian population. Though being a small retrospective study, results from this study have provided the medical community a real-world data on Asian (in particular Indian) population. In Hong Kong, we have reviewed our prospective database. 264 primary breast cancer patients underwent neoadjuvant chemotherapy followed by definitive breast surgery in my institution from 2005 to 2015. Mean age was 48.9 years old. Mean tumor size was 44.9 mm. 58 (22%) patients had HER2 positive invasive cancer. 16 (6.1%) were stage 1, 213 (80.7%%) were stage 2, the rest were stage 3 cancers. PCR rate was observed in 29 (11%) patients after neoadjuvant chemotherapy. Amongst which, PCR rate is higher in HER2 positive breast cancers (25.9%) followed by triple negative cancers (13.3%) and then luminal cancers (5.7%). Patients with HER2 positive cancers had 70.7% reduction of breast tumor volume on sonographic measurement after anti-HER2 neoadjuvant treatment. Breast cancers with HER2 positive cancers were associated with higher PCR rate (p= 0.029). Overall rate of breast conserving surgery (BCS) increased to from 14.7% to 30.5% after neoadjuvant treatment. Neoadjuvant systemic treatment results in significant tumor shrinkage in many patients. It has expanded the indication of BCS, although BCS rate in Asia remains relatively low due to personal choice and small breast volume in the population.

Predictors of Nodal Pathological Complete Response in Asian Women with Stage II-III Node-Positive Breast Cancer

BACKGROUND

Neoadjuvant chemotherapy (NAC) is increasingly used to treat node-positive (N+) breast cancer. Predictors of nodal pathological complete response (pCR) in Asian women are poorly described and there is variety in the management of the axilla after NAC. We evaluated predictors of nodal pCR and axillary management in a cohort of Asian N+ patients.

METHODS

Consecutive biopsy-proven N+ breast cancer patients treated with NAC were identified from the Shanghai Ruijin Hospital in China. Axillary lymph node dissection was performed on all patients, irrespective of the nodal response to NAC.

RESULTS

A total of 323 patients were included. Nodal pCR was achieved in 105 patients (33%), 15% of HR+/HER2- tumors, 38% of HR+/HER2+ tumors, 49% of HR-/HER2+ tumors, and 42% of HR-/HER2-tumors (p < 0.001). Factors associated with nodal pCR were (1) receptor status (HR+/HER2- [referent]: OR 3.42, 95% CI 1.43-8.16, p = 0.006 for HR+/HER2+; OR 4.19, 95% CI 1.85-9.50, p = 0.001 for HR-/HER2+; and OR 2.94, 95% CI 1.11-7.74, p = 0.029 for HR-/HER2-), (2) breast pCR (no pCR [referent]: OR 15.22, 95% CI 6.29-36.79, p < 0.001), and (3) absence of lymphovascular invasion (LVI [referent]: OR 9.04, 95% CI 2.09-39.18, p = 0.003).

CONCLUSION

This study confirmed expected predictors of nodal pCR in Asian women and the benefit of NAC in downstaging the axilla independently of ethnicity.

Association of plasma docetaxel levels with ABCB1 gene polymorphisms and tumour response in locally advanced breast cancer patients of South India on neo-adjuvant chemotherapy

BACKGROUND

Genetic factors could be attributed to the variability in docetaxel plasma levels and its subsequent therapeutic response. The objectives of this study were to assess the effect of ABCB1 gene polymorphisms [SNPs rs1045642 (C3435T) and rs1128503 (C1236T)] on docetaxel plasma levels and also to analyze the influence of docetaxel plasma levels on tumour response in the ethnically distinct South Indian population.

METHODS

104 locally advanced breast cancer (LABC) patients on docetaxel-based neo-adjuvant chemotherapy (NACT) were included. The plasma docetaxel levels were estimated using the validated reverse phase liquid chromatography with mass spectrometry (LC-MS/MS). DNA was extracted (phenol-chloroform extraction method) and the real-time PCR system using validated TaqMan® SNP genotyping assay method was used for genotyping. Tumour response was assessed by RECIST criteria based on the MRI images.

RESULTS

Patients with "CT/TT" genotype of the SNP C1236T had a C₀/C_t ratio of 1.6 times higher than those with "CC" genotype (13.5 ± 6.5 vs 8.3 ± 3.1, p = 0.002). Though not significant, patients with "CT/TT" genotype had greater initial plasma concentration (C₀) and area under the plasma concentration-time curve (AUC_0-t). Conversely, the SNP C3435T was not associated with the plasma docetaxel levels. Furthermore, the C₀ and normalized C₀ were found to be higher in tumour responders compared to non-responders (p < 0.05).

CONCLUSIONS

The plasma levels of docetaxel were significantly influenced by the SNP C1236T of ABCB1 gene coding for the MDR1 transporter (P-glycoprotein). The plasma levels of docetaxel were also found to influence its therapeutic effect.

Efficacy and safety of tailored and dose-dense adjuvant chemotherapy and trastuzumab for resected HER2-positive breast cancer: Results from the phase 3 PANTHER trial

BACKGROUND

Dose-dense (DD) adjuvant chemotherapy improves outcomes in early breast cancer (BC). However, there are no phase 3 randomized data to inform on its combination with trastuzumab for patients with human epidermal growth factor receptor 2 (HER2)-positive disease.

METHODS

This was a protocol-predefined secondary analysis of the randomized phase 3 Pan-European Tailored Chemotherapy (PANTHER) trial. Women 65 years old or younger with node-positive or high-risk, node-negative BC were randomized 1:1 to either tailored (according to hematologic nadirs) and DD epirubicin and cyclophosphamide followed by docetaxel or standard 5-fluorouracil, epirubicin, and cyclophosphamide plus docetaxel every 3 weeks. Patients with HER2-positive disease received 1 year of adjuvant trastuzumab. The primary endpoint was BC relapse-free survival. In addition, HER2-positive patients and an equal number of HER2-negative patients matched for age, treatment group, and institution who were enrolled at Swedish sites were asked to participate in a predefined study of cardiac safety and underwent echocardiography or multigated acquisition scanning and electrocardiography at the baseline and at 4 and 6 years of follow-up.

RESULTS

There were 342 HER2-positive patients; 335 received at least 1 dose of trastuzumab, and 29 patients discontinued trastuzumab prematurely. Relapse-free survival was not statistically significantly in favor of the tailored and DD group (hazard ratio, 0.68; 95% confidence interval, 0.37-1.27; P = .231). Cardiac outcomes after 4 and 6 years of follow-up did not differ significantly between HER2-positive and HER2-negative patients or between the 2 treatment groups.

CONCLUSIONS

The combination of DD chemotherapy and trastuzumab decreased the relative risk for relapse by 32% in comparison with standard treatment, a statistically nonsignificant difference. Its efficacy and safety merit further evaluation as part of both escalation and de-escalation strategies.

Are breast conservation treatment rates optimized for Asian women with symptomatic malignancies?

BACKGROUND

Published data indicate that 20-40% of patients undergo breast conservation treatment (BCT) in Asia, which is below an indicative benchmark of 50%. With an increasing body of evidence suggesting that BCT might be associated with improved survival outcomes, it is exigent to increase BCT utilization. This study was therefore undertaken to evaluate BCT rates for women presenting with symptomatic breast cancer and potential for de-escalation of surgical treatment.

METHODS

All patients who presented with symptomatic tumours and underwent surgical treatment at the authors' healthcare facility between January 2009 and December 2011 were included in this retrospective study. Standard wide excision was performed to achieve clear margins and reasonable cosmetic outcomes for BCT-eligible patients. Oncoplastic techniques such as therapeutic mammoplasty or volume replacement with flaps were not employed.

RESULTS

A total of 116 women presented with symptomatic breast cancer. The majority (92.2%) were Asian. Mean age at diagnosis was 48.3 years and mean tumour size was 23.4 mm. Ninety-five patients (81.9%) underwent BCT. Of the 22 patients, 13 (59%) who underwent neoadjuvant chemotherapy had sufficient tumour size downstaging to successfully undergo BCT instead of mastectomy.

CONCLUSION

It is possible for more than 80% of Asian women with symptomatic breast malignancies to undergo BCT, with the appropriate use of neoadjuvant medical therapy and surgical techniques. As increasing data indicate improved survival with BCT, this should be offered as the treatment of choice.

Is Multifocal Regression a Risk Factor for Ipsilateral Breast Tumor Recurrence in the Modern Era After Neoadjuvant Chemotherapy and Breast Conservation Therapy?

PURPOSE

Multifocal pattern of regression after neoadjuvant chemotherapy has been identified as a risk factor for ipsilateral breast tumor recurrence (IBTR). We aimed to determine the significance of multifocal regression as a predictor of IBTR after neoadjuvant chemotherapy and breast conservation therapy in the modern era.

METHODS AND MATERIALS

We retrospectively reviewed 346 patients treated between November 2009 and June 2017. Pattern of regression was categorized as pathologic complete response (pCR), unifocal (tumor present as a cohesive mass), limited multifocal (single cells or clusters of cells concentrated in 1 portion of the fibrotic area), or diffuse multifocal (cells spread over entire fibrotic area). IBTR was defined as new ipsilateral invasive or noninvasive breast tumor after breast conservation therapy. Predictive factors were analyzed using Cox regression.

RESULTS

Incidence of multifocal regression was 25.7% for the overall cohort and 12.2% for estrogen receptor (ER) negative/progesterone receptor (PR) negative/human epidermal growth factor receptor 2 (HER2) positive, 17.5% for triple-negative, 36.9% for ER+ or PR+/HER2-, and 38.5% for triple-positive (P < .001). With a median follow-up of 41.1 months, 4-year IBTR-free survival after pCR or unifocal regression versus multifocal regression was 94.1% versus 90.9% (P = .411). Pattern of regression (P = .010; compared to pCR, hazard ratio [HR] of 11.2 for diffuse multifocal regression, 1.65 for limited multifocal regression, and 3.81 for unifocal regression), phenotype (P = .001; compared to ER+ or PR+/HER2-, HR of 30.67 for ER-/PR-/HER2+, 25.30 for triple-negative, and 1.60 for triple-positive), and lack of nodal pCR (P = .004; HR of 3.78) predicted for IBTR on multivariate Cox regression. On multivariate subset analysis, pattern of regression and lymphovascular space invasion predicted for IBTR in hormone receptor-negative patients, but pattern of regression was not associated with IBTR for hormone receptor-positive patients.

CONCLUSIONS

Multifocal regression, hormone receptor-negative phenotype, and lack of nodal pCR predict for increased risk of IBTR after neoadjuvant chemotherapy. Although more common in hormone receptor-positive disease, multifocal regression was associated with worse outcome only in hormone receptor-negative patients.

Present and changing trends in surgical modalities and neoadjuvant chemotherapy administration for female breast cancer in Beijing, China: A 10-year (2006-2015) retrospective hospitalization summary report-based study

BACKGROUND

This study was conducted to describe present and changing trends in surgical modalities and neoadjuvant chemotherapy (NACT) in female breast cancer patients in China from 2006 to 2015.

METHODS

Data of 44 299 female breast cancer patients from 15 tertiary hospitals in Beijing were extracted from hospitalization summary reports. Surgeries were categorized into five modalities: breast-conserving surgery (BCS), simple mastectomy (SM), modified radical mastectomy (MRM), radical mastectomy (RM), and extensive radical mastectomy (ERM).

RESULTS

In total, 38 471 (86.84%) breast cancer patients underwent surgery: 22.64% BCS, 8.22% SM, 63.97% MRM, 4.24% RM, and 0.93% ERM. Older patients (> 60) underwent surgery more frequently than younger patients (< 60). The proportion of patients who underwent BCS was highest in the age ≥ 80 (39.24%) and < 40 (28.69%) subgroups and in patients with papillary carcinoma (35.48%), and lowest in the age 60- subgroup (18.17%) and in patients with Paget's disease (19.05%). SM was most frequently performed in patients with Paget's disease (29.00%), and MRM for ductal (64.99%), and lobular (63.78%) carcinomas. During the study period, the proportion of patients who underwent MRM dropped by 29.04%, SM and BCS increased from 15.78% and 30.83%, respectively, and NACT increased in all subgroups, particularly in patients with lymph node involvement (26.72%).

CONCLUSIONS

Surgical modalities varied significantly by age and histologic group. The use of BCS and SM increased dramatically, while MRM declined significantly. The proportion of patients treated with NACT has increased significantly, especially in patients with lymph node involvement.

Assessment of the predictive role of pretreatment Ki-67 and Ki-67 changes in breast cancer patients receiving neoadjuvant chemotherapy according to the molecular classification: a retrospective study of 1010 patients

PURPOSE

To assess the predictive role of pretreatment ki67 and Ki67 changes in breast cancer (BC) patients treated with neoadjuvant chemotherapy (NAC) in various molecular subtypes.

METHODS

1010 BC patients who had undergone anthracycline and taxane-based NAC from January 2012 to July 2017 were retrospectively analyzed. Clinical and pathological parameters of the patients were retrieved and the predictive factors for NAC response were evaluated.

RESULTS

705 patients showed clinical response (cRes), and 131 patients acquired pathologic complete response (pCR). Patients with higher pretreatment Ki67 (≥ 14%), tumor size ≥ 4 cm, and positive clinical nodal had better clinical therapy response, while patients with negative ER and PR, higher pretreatment Ki67 (≥ 14%), and tumor size < 4 cm were more probable to attain pCR. The pretreatment Ki67 could be used as a predictor of NAC only in luminal subtypes, and 25.5% were identified as an ideal cut-off point to differentiate the cRes from non-cRes cases. Although a decrease in Ki67 had been found in almost all molecular subtypes after NAC, no statistically significant differences were found in the decrease of Ki67 were validated between the cRes and non-cRes group in HER2-rich and triple-negative subtypes (P = 0.488 and P = 0.111, respectively).

CONCLUSIONS

The best cut-off for pretreatment Ki67 in predicting the connection with the tumor size lessening was 25.5% in luminal subtype. Aggressive adjuvant systemic treatments should be considered for patients with HER2-rich and triple-negative subtype who exhibit tumor shrinkage in NAC but still have high levels of Ki67.

Oncological outcome of complete response after neoadjuvant chemotherapy for breast conserving surgery: a systematic review and meta-analysis

BACKGROUND

With limited sample sizes and single-institution designs, how complete response (CR) after neoadjuvant chemotherapy (NAC) influences breast conserving surgery (BCS) and its value in prognosis are not clear.

METHODS

A systematic research review was conducted using electronic database. The rate of clinical complete response (cCR) in BCS after NAC and these pathological CR (PCR) and non-pCR BCS patients' local recurrence-free survival (LRFS), distance recurrence-free survival (DRFS), overall survival (OS), and disease-free survival (DFS) rates were collected. A pooled analysis was performed using a fixed or random effects model and a Q test to determine heterogeneity.

RESULTS

Sixteen studies with a total of 4639 patients were included. The pooled data revealed that cCR patients compared with non-cCR patients had significantly higher rates of BCS, with a summary estimate odds ratios (OR) of 4.54 (95% CI 2.03-10.17). The pooled data revealed that BCS patients who achieved pCR after NAC had significantly lower rates of LRFS (RR = 0.59, 95% CI 0.38-0.92) and DRFS (RR = 0.27, 95% CI 0.13-0.55). Better DFS (RR = 0.09, 95% CI 0.04-0.25) and OS (RR = 0.36, 95% CI 0.03-3.90) were also seen, but OS was not significantly different.

CONCLUSIONS

The rate of successful BCS is higher in the cCR group than in the non-cCR group, means cCR after NAC can encourage patients to receive BCS. The achievement of pCR after NAC in BCS patients was associated with a good prognosis in terms of LRFS and DRFS, but its value in DFS and OS requires further investigation.

Outcome after neoadjuvant chemotherapy in Asian breast cancer patients

We aim to identify clinicopathologic predictors for response to neoadjuvant chemotherapy and to evaluate the prognostic value of pathologic complete response (pCR) on survival in Asia. This study included 915 breast cancer patients who underwent neoadjuvant chemotherapy at five public hospitals in Singapore and Malaysia. pCR following neoadjuvant chemotherapy was defined as 1) no residual invasive tumor cells in the breast (ypT0/is) and 2) no residual invasive tumor cells in the breast and axillary lymph nodes (ypT0/is ypN0). Association between pCR and clinicopathologic characteristics and treatment were evaluated using chi-square test and multivariable logistic regression. Kaplan-Meier analysis and log-rank test, stratified by other prognostic factors, were conducted to compare overall survival between patients who achieved pCR and patients who did not. Overall, 4.4% of nonmetastatic patients received neoadjuvant chemotherapy. The median age of preoperatively treated patients was 50 years. pCR rates were 18.1% (pCR ypT0/is) and 14.4% (pCR ypT0/is ypN0), respectively. pCR rate was the highest among women who had higher grade, smaller size, estrogen receptor negative, human epidermal growth factor receptor 2-positive disease or receiving taxane-based neoadjuvant chemotherapy. Patients who achieved pCR had better overall survival than those who did not. In subgroup analysis, the survival advantage was only significant among women with estrogen receptor-negative tumors. Patients with poor prognostic profile are more likely to achieve pCR and particularly when receiving taxane-containing chemotherapy. pCR is a significant prognostic factor for overall survival especially in estrogen receptor-negative breast cancers.