High expression of post-treatment Ki-67 status is a risk factor for locoregional recurrence following breast-conserving surgery after neoadjuvant chemotherapy

The Evolution of Ki-67 and Breast Carcinoma: Past Observations, Present Directions, and Future Considerations

The 1983 discovery of a mouse monoclonal antibody-the Ki-67 antibody-that recognized a nuclear antigen present only in proliferating cells represented a seminal discovery for the pathologic assessment of cellular proliferation in breast cancer and other solid tumors. Cellular proliferation is a central determinant of prognosis and response to cytotoxic chemotherapy in patients with breast cancer, and since the discovery of the Ki-67 antibody, Ki-67 has evolved as an important biomarker with both prognostic and predictive potential in breast cancer. Although there is universal recognition among the international guideline recommendations of the value of Ki-67 in breast cancer, recommendations for the actual use of Ki-67 assays in the prognostic and predictive evaluation of breast cancer remain mixed, primarily due to the lack of assay standardization and inconsistent inter-observer and inter-laboratory reproducibility. The treatment of high-risk ER-positive/human epidermal growth factor receptor-2 (HER2) negative breast cancer with the recently FDA-approved drug abemaciclib relies on a quantitative assessment of Ki-67 expression in the treatment decision algorithm. This further reinforces the urgent need for standardization of Ki-67 antibody selection and staining interpretation, which will hopefully lead to multidisciplinary consensus on the use of Ki-67 as a prognostic and predictive marker in breast cancer. The goals of this review are to highlight the historical evolution of Ki-67 in breast cancer, summarize the present literature on Ki-67 in breast cancer, and discuss the evolving literature on the use of Ki-67 as a companion diagnostic biomarker in breast cancer, with consideration for the necessary changes required across pathology practices to help increase the reliability and widespread adoption of Ki-67 as a prognostic and predictive marker for breast cancer in clinical practice.

Differences in sensitivity to neoadjuvant chemotherapy among invasive lobular and ductal carcinoma of the breast and implications on surgery-A systematic review and meta-analysis

Meta-analysis of >87,000 patients demonstrates that patients with invasive lobular carcinoma of the breast are far less likely to achieve pCR of the breast or axilla compared to their ductal counterparts, receive less BCS and more frequently return positive margins.

BACKGROUND

Neoadjuvant chemotherapy (NACT) facilitates tumour downstaging, increases breast conserving surgery (BCS) and assesses tumour chemosensitivity. Despite clinicopathological differences in Invasive Ductal Carcinoma (IDC) and Invasive Lobular Carcinoma (ILC), decision making surrounding the use NACT does not take account of histological differences.

AIM

To determine the impact NACT on pathological complete response (pCR), breast conserving surgery (BCS), margin status and axillary pCR in ILC and IDC.

METHODS

A systematic review was performed in accordance with the PRISMA guidelines. Studies reporting outcomes among ILC and IDCs following NACT were identified. Dichotomous variables were pooled as odds ratios (ORs) with 95% confidence intervals_(CI) using the Mantel-Haenszel method. P-values <0.05 were statistically significant.

RESULTS

40 studies including 87,303 (7596 ILC [8.7%]and 79,708 IDC [91.3%]) patients were available for analysis. Mean age at diagnosis was 54.9 vs. 50.9 years for ILC and IDC, respectively. IDCs were significantly more likely to achieve pCR (22.1% v 7.4%, OR: 3.03 [95% CI 2.5-3.68] p < 0.00001), axillary pCR (23.6% vs. 13.4%, OR: 2.01 [95% CI 1.77-2.28] p < 0.00001) and receive BCS (45.7% vs. 33.3%, OR 2.14 [95% CI 1.87-2.45] p < 0.00001) versus ILCs. ILCs were significantly more likely to have positive margins at the time of surgery (36% vs 13.5%, OR 4.84 [95% CI 2.88-8.15] p < 0.00001).

CONCLUSION

This is the largest study comparing the impact of NACT among ILC and IDC with respect to pCR and BCS. ILC has different outcomes to IDC following NACT and incorporate it into treatment decisions and future clinical guidelines.

Factors Predicting Locoregional Recurrence After Neoadjuvant Chemotherapy and Nipple-Sparing/Skin-Sparing Mastectomy With Immediate Breast Reconstruction

Background

Few data are available on the risk factors of locoregional recurrence (LRR) after neoadjuvant chemotherapy (NACT) and immediate breast reconstruction (IBR) in breast cancer. Herein, we evaluated the factors predicting LRR in a large series of patients who underwent either nipple- (NSM) or skin-sparing mastectomy (SSM) with IBR after NACT.

Methods

We retrospectively analyzed 609 breast cancer patients who underwent NACT and NSM/SSM with IBR between February 2010 and June 2017. Factors associated with an increased risk of LRR were analyzed by univariate (chi-square or Fisher's exact test) and multivariate (Cox proportional hazard regression model) analyses.

Results

During a median follow-up of 63 months, LRR as the first event occurred in 73 patients, and the 5-year cumulative LRR rate was 10.8%. Multivariate analysis revealed post-NACT Ki67 ≥ 10% [hazard ratio (HR), 2.208; 95% confidence interval (CI), 1.295-3.765; P = 0.004], high tumor grade (HR, 1.738; 95% CI, 1.038-2.908; P = 0.035), and presence of lymphovascular invasion (LVI) (HR, 1.725; 95% CI, 1.039-2.864; P = 0.035) as independently associated with increased LRR risk. The 10-year LRR rate was 8.5% for patients with none of the three associated risk factors, 11.6% with one factor, 25.1% with two factors, and 33.7% with all three factors (P < 0.001).

Conclusions

Post-NACT Ki67 ≥ 10%, high tumor grade, and presence of LVI are independently associated with an increased risk of developing LRR after NACT and NSM/SSM with IBR. Future prospective trials are warranted to decrease the risk of LRR in patients with associated risk factors.

Correlation between outcome and extent of residual disease in the sentinel node after neoadjuvant chemotherapy in clinically fine-needle proven node-positive breast cancer patients

BACKGROUND

Whether the extent of residual disease in the sentinel lymph node (SLN) after neoadjuvant chemotherapy (NAC) influences the prognosis in clinically node-positive breast cancer (BC) patients remains to be ascertained.

METHODS

One hundred and thirty-four consecutive cN+/BC-patients received NAC followed by SLN biopsy and axillary lymph node dissection. Cumulative incidence of overall (OS) and disease-free (DFS) survival, BC-related recurrences and death from BC were assessed using the Kaplan-Meier method both in the whole patient population and according to the SLN status. The log rank test was used for comparisons between groups.

RESULTS

The SLN was identified in 123/134 (91.8%) patients and was positive in 98/123 (79.7%) patients. Sixty-five of them (66.3%) had other axillary nodes involved. SLN sensitivity and false-negative rate were 88.0% and 2.0%, Median follow-up was 10.2 years. Ten-year cumulative incidence of axillary, breast and distant recurrences, and death from BC were 6.5%, 11.9%, 33.4% and 31.3%, respectively. Ten-year OS and DFS were 67.3% and 55.9%. When stratified by SLN status, 10-year cumulative incidence of BC-related and loco-regional events, and death from BC were similar between disease-free SLN and micrometastatic SLN subgroups (28.9% vs 30.2%, p = 0.954; 21.6% vs 13.4%, p = 0.840; 12.9 vs 24.5%, p=0.494). Likewise, 10-year OS and DFS were comparable (80.0% vs 75.5%, p=0.975 and 68.0% vs 69.8, p=0.836). Both OS and DFS were lower in patients presenting a macrometastatic SLN (60.2% and 47.5%).

CONCLUSION

Outcome of patients with micrometastatic SLN was similar to that of patients with disease-free SLN, which was more favorable as compared to that of patients with macrometastatic SLN.

6 versus 12 months of adjuvant trastuzumab in HER2+ early breast cancer: A systematic review and meta-analysis

BACKGROUND

Adjuvant trastuzumab improves survival outcomes of human epidermal receptor 2 positive early breast cancer patients. Currently, administration of 12 months adjuvant trastuzumab is the standard therapy. However, whether 6 months treatment is non-inferior to the standard 12 months treatment remains controversial.

METHODS

Relevant records were searched in PubMed, Cochrane Library, Web of Science, and EMBASE through Jan 14, 2020. Pooled hazard ratios (HRs) and 95% confidence intervals (CIs) for disease-free survival (DFS) and overall survival (OS) were meta-analyzed. The primary endpoint was DFS with a non-inferiority hazard margin of 1.2 and the second was OS with 1.43.

RESULTS

Three randomized clinical studies met the inclusion criteria, including 3974 patients in 6 months group and 3976 in 12 months group. HR for DFS was 1.18 (95% CI 0.97-1.44, P = .09), with the non-inferiority margin comprised in the 95% CI. HR for OS was 1.14 (95% CI 0.98-1.32, P= .08), whereas the upper limit of 95% CI did not exceed the non-inferiority hazard margin.

CONCLUSION

Our analysis failed to show that 6 months treatment was non-inferior to 12 months treatment in improving the DFS. Although the non-inferiority of the 6-month adjuvant trastuzumab treatment was found for OS, considering that breast cancer patients should receive additional systematic therapies when disease progression or relapse happens, we suggest that 12 months adjuvant trastuzumab treatment should remain the standard therapeutic strategy for patients with early human epidermal receptor 2 positive breast cancer.

Impact on survival of estrogen receptor, progesterone receptor and Ki-67 expression discordance pre- and post-neoadjuvant chemotherapy in breast cancer

PURPOSE

To investigate whether estrogen receptor (ER), progesterone receptor (PR) and Ki-67 expression discordance before and after neoadjuvant chemotherapy (NAC) correlates with prognosis and treatment of breast cancer patients.

METHODS

The study cohort included 482 breast cancer patients at the Zhejiang Cancer Hospital from January 1, 2008, to December 31, 2018. Core needle biopsies and excised tissue biopsies pre- and post-NAC were obtained. Immunohistochemistry was used to determine ER, PR and Ki-67 status. The relationship between biomarker discordance before and after NAC and clinicopathological features was compared retrospectively.

RESULTS

ER (n = 482), PR (n = 482) and Ki-67 (n = 448) expression was assessed in the same lesion pre- and post-NAC. Discordance in the three markers pre- and post-NAC was observed in 50 (10.4%), 82 (17.0%) and 373 (77.4%) cases, respectively. Positive-to-negative PR expression changes were the most common type of discordance observed. The risk of death in patients with a PR positive-to-negative conversion was 6.58 times greater than for patients with stable PR expression. The risk of death in patients with increased Ki-67 expression following NAC treatment was 2.05 times greater than for patients with stable Ki-67 expression.

CONCLUSION

Breast cancer patients showed changes in ER, PR and/or Ki-67 status throughout NAC, and these changes possibly influenced disease-free survival and overall survival. A switch to negative hormone receptor expression with increased Ki-67 expression following NAC could be indicators of a worse prognosis. Biomarker expression investigations following NAC may potentially improve patient management and survival.

Oncologic Outcomes of Nipple-sparing Mastectomy and Immediate Reconstruction After Neoadjuvant Chemotherapy for Breast Cancer

OBJECTIVES

To evaluate the oncologic outcomes and risk factors for locoregional recurrence (LRR) and nipple-areola complex recurrence (NR) in a large series of breast cancer patients who underwent nipple-sparing mastectomy (NSM) and immediate reconstruction after neoadjuvant chemotherapy (NACT).

SUMMARY OF BACKGROUND DATA

The use of NSM and immediate reconstruction in breast cancer patients receiving NACT is increasing. However, the oncologic safety of this approach is unclear.

PATIENTS AND METHODS

A total of 310 breast cancer patients (319 breasts) who underwent NACT and NSM between February 2010 and November 2016 were retrospectively analyzed. Clinical and pathologic factors associated with increased risks of LRR and NR were analyzed using univariate (Chi-square or Fisher exact test) and multivariate (Cox proportional hazard regression model) analyses.

RESULTS

During a mean follow-up of 63 ± 22 months, 38 cases had LRR as the first event, including 6 cases of NR as the first event. The 5-year cumulative LRR and NR rates were 11.0% and 1.9%, respectively. In univariate analysis, clinical T stage, pathologic nodal status, histologic grade, lymphovascular invasion, and post-NACT Ki67 status were associated with increased LRR risk, and post-NACT Ki67 status was the only significant risk factor for NR. In multivariate analysis, post-NACT Ki67 ≥10% (hazard ratio, 4.245; 95% confidence interval, 1.865-9.663; P = 0.001) was an independent risk factor for LRR.

CONCLUSIONS

NSM and immediate reconstruction seem to be oncologically safe with acceptable LRR and NR rates for appropriately selected breast cancer patients treated with NACT. Post-NACT Ki67 ≥10% was associated with increased risk of LRR or NR, and therefore, necessitates cautious follow-up.

The reciprocal influences of prognosis between two types of surgical interventions and early breast cancer patients with diverse luminal subtypes: A meta-analysis

BACKGROUND

To investigate and compare the effects of breast-conserving therapy (BCT) and mastectomy on the disease recurrence and long-term survival in early-stage luminal breast cancer and the difference in prognosis across diverse luminal subtypes receiving single surgical modality.

METHODS

The databases of PubMed and Embase were retrieved to select eligible trials that were published from inception to 13 November 2018. The clinical trials that offered the details about recurrent disease and/or survival in luminal tumors underwent BCT or mastectomy met the inclusion criteria (n=24). With the random- or fixed-effect model basing on heterogeneity Chi test with its significant level of P < .1, pooled odds ratio (OR) with its 95% CI, and P value were identified for endpoints.

RESULTS

The analyzed data were constituted of 25 qualified trials with 13,032 unique women suffered from luminal cancers. The fixed-effect models were utilized. On the LRR regarding BCT versus mastectomy, the pooled data indicated no significant difference in luminal carcinomas (OR, 0.84; 95%CI, 0.43-1.64; P = .61; n = 867). In BCT cohort, the pooled data showed that there were some significant benefits favoring luminal A over luminal B in LR (OR, 0.61; 95%CI, 0.46-0.81; P = .0007; n = 5406), DM (OR, 0.53; 95%CI, 0.41-0.69; P < .00001; n = 4662), DFS (OR, 0.59; 95%CI, 0.36-0.96; P = .03; n = 776) and OS (OR, 0.65; 95%CI, 0.42-0.99; P = .05; n = 1149), but not in LRR (OR, 0.74; 95%CI, 0.48-1.13; P = .16; n = 3732), coupled with luminal A/B over luminal-HER2 in LRR (OR, 0.43; 95%CI, 0.25-0.76; P = .004; n = 890), DM (OR, 0.56; 95%CI, 0.35-0.90; P = .02; n = 1396), DFS (OR, 0.47; 95%CI, 0.27-0.83; P = .009; n = 532); in mastectomy cohort, there were apparent advantages of LRR (OR, 0.58; 95%CI, 0.36-0.92; P = .02; n = 1768), LR (OR,0.56; 95%CI, 0.38-0.83; P = .004; n = 1209), DM (OR, 0.58; 95%CI, 0.40-0.84; P = .004; n = 652) and OS (OR, 0.62; 95%CI, 0.43-0.89; P = .009; n = 652) in luminal A vs luminal B.

CONCLUSION

For early luminal breast cancer, the equality of LRR was achieved in BCT and mastectomy. In comparison, luminal A cancers benefit the most improved tumor re-appearence and survival in luminal diseases regardless of the option of surgical modality, whereas luminal-HER2 is affected by the worst clinical outcomes in them who follows BCT.

Post-neoadjuvant treatment and the management of residual disease in breast cancer: state of the art and perspectives

Achieving a pathologic complete response after neoadjuvant treatment is associated with improved prognosis in breast cancer. The CREATE-X trial demonstrated a significant survival improvement with capecitabine in patients with residual invasive disease after neoadjuvant chemotherapy, and the KATHERINE trial showed a significant benefit of trastuzumab-emtansine (TDM1) in human epidermal growth factor receptor 2 (HER2)-positive patients who did not achieve a pathologic complete response after neoadjuvant treatment, creating interesting alternatives of post-neoadjuvant treatments for high-risk patients. New agents are arising as therapeutic options for metastatic breast cancer such as the cyclin-dependent kinase inhibitors and the immune-checkpoint inhibitors, but none has been incorporated into the post-neoadjuvant setting so far. Evolving techniques such as next-generation sequencing and gene expression profiles have improved our knowledge regarding the biology of residual disease, and also on the mechanisms involved in treatment resistance. The present manuscript reviews the current available strategies, the ongoing trials, the potential biomarker-guided approaches and the perspectives for the post-neoadjuvant treatment and the management of residual disease after neoadjuvant treatment in breast cancer.

Clinical decision making in postmastectomy radiotherapy in node negative breast cancer

For decades, postmastectomy radiotherapy (PMRT) has been recommended for node positive [N(+)] breast cancer patients; nevertheless, the beneficial effect of PMRT for treatment of node negative [N(−)] disease remains under discussion. Nowadays, the biology of breast cancer and the risk factors (RFs) for locoregional failure (LRF) must be included in the decision on whether or not to carry out PMRT. For these reasons, the present review aims to evaluate the rationale use of PMRT in N(−) patients and discuss which subgroups may further benefit from the treatment in present times where the decision must be personalised, according to the RFs of locoregional recurrence (LRR). To perform the analysis, we ponder that LRR of over 10% should be considered unacceptable due to the fact that LRRs generate great morbidity in patients. For this purpose, we consider that routine RT in these patients is not recommended, although there are subgroups of patients with high LRR, in which PMRT could be beneficial.

Eph A10-modified pH-sensitive liposomes loaded with novel triphenylphosphine-docetaxel conjugate possess hierarchical targetability and sufficient antitumor effect both in vitro and in vivo

Mitochondrial-targeting therapy was considered to be a promising approach for the efficient treatment of cancer while positive charge induced nonspecific cytotoxicity severely limits its application. To overcome this drawback, a novel mitochondria targeted conjugate triphenylphosphine-docetaxel (TD) has been synthesized successfully and incorporated it into liposomes (EPSLP/TD), which possessed excellent pH-sensitive characteristic, EphA 10 mediated active targetability as well as mitochondria-targeting capability. EPSLP/TD was characterized to have a small particle size, high-encapsulation efficiency and excellent pH-sensitive characteristic. Compared with DTX-loaded liposomes (EPSLP/DTX), EPSLP/TD possessed higher cytotoxicity against MCF-7 cell line. Mitochondrial-targeting assay demonstrated mitochondria-targeting moiety triphenylphosphine (TPP) could efficiently deliver DTX to mitochondria. Western immunoblotting assay indicated that EPSLP/TD could efficiently deliver antitumor drug to mitochondria and induce cell apoptosis via mitochondria-mediated apoptosis pathway. In vivo antitumor study demonstrated EPSLP/TD owed excellent in vivo antitumor activity. Histological assay demonstrated EPSLP/TD showed strongly apoptosis inducing effect, anti-proliferation effect and anti-angiogenesis effect. This work investigated the potential of hierarchical targeting pH-sensitive liposomes is a suitable carrier to activate mitochondria-mediated apoptosis pathway for cancer therapy.

Critical review of axillary recurrence in early breast cancer

Around 2% of early breast cancer cases treated with axillary lymph node dissection (ALND) underwent axillary recurrence (AR) and it has a deleterious effect in prognosis. Different scenarios have incorporated Sentinel Lymph Node (SLN) Biopsy (SLNB) instead of ALND as part of the standard treatment and more effective systemic treatment has also been incorporated in routine management after first curative surgery and after regional recurrence. However, there is concern about the effect of SLNB alone over AR risk and how to predict and treat AR. SLN biopsy (SLNB) has been largely accepted as a valid option for SLN-negative cases, and recent prospective studies have demonstrated that it is also safe for some SLN-positive cases and both scenarios carry low AR rates. Different studies have identified clinicopathological factors related to aggressiveness as well as high-risk molecular signatures can predict the development of locoregional recurrence. Other publications have evaluated factors affecting prognosis after AR and find that time between initial treatment and AR as well as tumor aggressive behavior influence patient survival. Retrospective and prospective studies indicate that treatment of AR should include local and systemic treatment for a limited time.

Ki67 Changes Identify Worse Outcomes in Residual Breast Cancer Tumors After Neoadjuvant Chemotherapy

BACKGROUND

Several breast cancer (BC) trials have adopted pathological complete response (pCR) as a surrogate marker of long-term treatment efficacy. In patients with luminal subtype, pCR seems less important for outcome prediction. BC is a heterogeneous disease, which is evident in residual tumors after neoadjuvant-chemotherapy (NAC). This study evaluates changes in Ki67 in relation to disease-free survival (DFS) and overall survival (OS) in patients without pCR.

SUBJECTS, MATERIALS, AND METHODS

Four hundred thirty-five patients with stage IIA-IIIC BC without pCR after standard NAC with anthracycline and paclitaxel were analyzed. We analyzed the decrease or lack of decrease in the percentage of Ki67-positive cells between core biopsy samples and surgical specimens and correlated this value with outcome.

RESULTS

Twenty-five percent of patients presented with luminal A-like tumors, 45% had luminal B-like tumors, 14% had triple-negative BC, 5% had HER2-positive BC, and 11% had triple-positive BC. Patients were predominantly diagnosed with stage III disease (52%) and high-grade tumors (46%). Median Ki67 level was 20% before NAC, which decreased to a median of 10% after NAC. Fifty-seven percent of patients had a decrease in Ki67 percentage. Ki67 decrease significantly correlated with better DFS and OS compared with no decrease, particularly in the luminal B subgroup. Multivariate analysis showed that nonreduction of Ki67 significantly increased the hazard ratio of recurrence and death by 3.39 (95% confidence interval [CI] 1.8-6.37) and 7.03 (95% CI 2.6-18.7), respectively.

CONCLUSION

Patients without a decrease in Ki67 in residual tumors after NAC have poor prognosis. This warrants the introduction of new therapeutic strategies in this setting.

IMPLICATIONS FOR PRACTICE

This study evaluates the change in Ki67 percentage before and after neoadjuvant chemotherapy (NAC) and its relationship with survival outcomes in patients with breast cancer who did not achieve complete pathological response (pCR). These patients, a heterogeneous group with diverse prognoses that cannot be treated using a single algorithm, pose a challenge to clinicians. This study identified a subgroup of these patients with a poor prognosis, those with luminal B-like tumors without a Ki67 decrease after NAC, thus justifying the introduction of new therapeutic strategies for patients who already present a favorable prognosis (luminal B-like with Ki67 decrease).

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.

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.