Prognostic value of receptor conversion after neoadjuvant chemotherapy in breast cancer patients: a prospective observational study

HER2-positive is an independent indicator for predicting pathological complete response to neoadjuvant therapy and Ki67-changed after neoadjuvant chemotherapy predicts favorable prognosis in Chinese women with locally advanced breast cancer

The growing body of evidence suggests that breast cancer (BC) who achieve pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) may experience a more favorable prognosis. The objective of this study is to investigate the correlation between clinicopathologic parameters of locally advanced breast cancer (LABC) patients and the outcomes of NAC, with the aim of identifying predictive indicators for pCR. Additionally, we seek to examine the conversion of IHC markers in pCR patients following NAC and its impact on the prognosis of BC patients. We conducted a study involving 126 patients with LABC. Clinicopathological parameters associated with pCR were subjected to univariate and multivariate analysis. Kaplan-Meier (KM) curves and the log-rank test were used to compare the statistical difference in prognosis in different groups of patients. Additionally, we used difference and consistency tests to examine the conversion of immunohistochemistry (IHC) markers following NAC. The status of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and molecular subtypes of BC were associated with pCR in the univariate analysis (all P < .05), which may be potential markers to predict pCR. HER2 was identified as an independent factor for predicting pCR in the multivariate analysis. The pCR rate of HER2-positive patients who received NAC combined targeted therapy was higher than that of patients who only received NAC (P = .003). The disease-free survival (DFS) rate of TNBC patients who achieved pCR was significantly higher than that of non-pCR TNBC patients (P = .026). The IHC marker conversion after NAC mainly existed in PR (P = .041). Ki67 expression decreased in the luminal B subtype and increased in the HER2 enriched subtype after NAC (all P < .001). Patients with Ki67 expression change after NAC had longer overall survival (OS) and DFS than unchanged patients (all P < .05). HER2-positive is an independent indicator for predicting pCR, and HE2-positive patients who received NAC combined targeted therapy were favorable to achieving pCR. IHC markers of BC patients exhibit varying degrees of alterations after NAC, and changes in Ki67 expression after NAC could serve as a marker to predict a better prognosis.

Prognostic impact of reduced HER2 protein expression in post-neoadjuvant therapy resection specimens: A single institution experience and review of the literature

BACKGROUND

Retesting for Human epidermal growth factor receptor-2 (HER2) in post-neoadjuvant therapy resection is variable, and data is conflicting regarding the prognostic significance of changes in HER2 expression pre and post therapy.

METHODS

We identified 104 patients with localized HER2 IHC 3+ breast cancer who received neoadjuvant trastuzumab(T)/pertuzumab(P) containing chemotherapy at Yale Cancer Center between 2012 and 2022. Patients were divided into 3 cohorts by response and HER2 IHC in the residual disease: Cohort 1 pathologic complete response (pCR), Cohort 2 pre-treatment IHC 3+/post treatment IHC 1+/2+, and Cohort 3 pre-treatment IHC 3+/post-treatment IHC 3+. Kaplan-Meier survival analysis was performed to assess recurrence free survival at 36 months.

RESULTS

The overall pCR rate was 62.5% (65/104), while 37.5% (39/104) of patients had residual disease (RD). Among patients with RD, 58.9% (23/39) remained IHC 3+ and 41.1% (16/39) had reduced HER2 expression IHC1+ or 2+. In patients with HER2 IHC 3+ RD, 26% (6/23) developed local recurrence or distant metastasis while none of patients with post NAT HER2 IHC 1+ or 2+ RD had relapse (p = 0.0309). In patients with pCR, 6.15% (4/65) had recurrence. Kaplan-Meier survival analysis revealed superior disease-free survival in patients with reduced HER2 IHC expression compared to those with remained IHC 3+ (log rank p = 0.004).

CONCLUSION

We conclude that reduced HER2 expression by IHC following neoadjuvant treatment was associated with lower recurrence rates in HER2 IHC 3+ breast cancer. If confirmed, RD HER2 IHC expression could be used as a prognostic biomarker to stratify patients in adjuvant trials and identify patients who may benefit from more intensive adjuvant therapy and post therapy surveillance.

Receptor conversion and survival in breast cancer liver metastases

BACKGROUND

Breast cancer liver metastases (BCLM) is a common cause of breast cancer-related death. The prognostic and predictive value of receptor expression and St Gallen classification is challenged by receptor status discordance in distant metastases. The aim of this study was to determine the rate of receptor conversion from breast cancer to BCLM and the impact on survival.

METHOD

Patients registered with BCLM in two Swedish national cancer registers were recruited retrospectively. Data on receptor expression in primary breast cancer and BCLM were collected, as well as information about predictive factors for survival. The rate of receptor and subtype conversion was analyzed. A Cox regression model was used to investigate predictive factors for survival.

RESULTS

A cohort of 132 patients with BCLM was identified. Estrogen receptor (ER), progesterone receptor (PgR) and HER2 converted in 17, 33 and 10%, respectively. PgR was lost in BCLM while 8/10 HER2 conversions went from negative to positive. The BC subtype was re-classified in 21% of the BCLM. Median survival after BCLM was 13 months and HER2 amplification was associated with improved survival (HR 0.28 CI 0.085-0.90). The highest predictive value (Harrell´s C-index) was obtained when including both BC and BCLM status.

CONCLUSIONS

Receptor and subtype conversions are common in BCLM, and a liver biopsy is warranted to tailor BCLM treatment. HER2 amplification is associated with improved survival in a BCLM cohort.

Clinical implications of receptor conversions in breast cancer patients who have undergone neoadjuvant chemotherapy

PURPOSE

In this study, we aimed to determine the incidence of receptor conversions after neoadjuvant chemotherapy (NAC) for breast cancer and assess the rate at which receptor conversion leads to changes in adjuvant therapy regimens.

METHODS

We performed a retrospective review of female breast cancer patients treated with NAC at an academic breast center between January 2017 and October 2021. Patients with residual disease on surgical pathology and complete receptor status information for both pre-NAC and post-NAC specimens were included. Incidence of receptor conversions, defined as a change in at least one hormone receptor (HR) or HER2 status compared to preoperative specimens, was tabulated, and adjuvant therapy modalities were reviewed. Factors associated with receptor conversion were analyzed using chi-square tests and a binary logistic regression.

RESULTS

Of the 240 patients with residual disease after NAC, 126 (52.5%) had receptor testing repeated. After NAC, 37 specimens (29%) had a receptor conversion. Receptor conversion resulted in the addition or removal of an adjuvant therapy in 8 patients (6%), indicating a number needed to screen of 16. Prior history of cancer, receipt of initial biopsy at an outside site, HR-positive tumors, and a pathologic stage of II or lower were factors associated with receptor conversions.

CONCLUSION

HR and HER2 expression profiles frequently change after NAC and drive adjustments in adjuvant therapy regimens. Repeat testing of HR and HER2 expression should be considered in patients who receive NAC, especially in patients with early stage, HR-positive tumors whose initial biopsies were performed externally.

Pre- and Post-Neoadjuvant Clinicopathological Parameters Can Help in the Prognosis and the Prediction of Response in HER2+ and Triple Negative Breast Cancer

Neoadjuvant treatment (NAT) is one of the most widely used options for HER2+ and triple negative (TN) early breast cancer (BC). Since around half of the patients treated with NAT do not achieve a pathologically complete response (pCR), biomarkers to predict resistance are urgently needed. The correlation of clinicopathological factors with pCR was studied in 150 patients (HER2 = 81; TN = 69) and pre- and post-NAT differences in tumour biomarkers were compared. Low estrogen receptor (ER) expression, high tumour-infiltrating lymphocytes (TILs) and low cT-stage were associated with pCR in HER2+ tumours (p = 0.022; p = 0.032 and p = 0.005, respectively). Furthermore, ER expression was also associated with residual cancer burden (RCB; p = 0.046) in the HER2+ subtype. Similarly, pre-NAT, low progesterone receptor expression (PR; 1-10%) was associated with higher RCB (p < 0.001) in TN tumours. Only clinical and pathological T-stage (cpT-stage) had prognostic capacity in HER2+ tumours, whereas pre-NAT cpT-stage and post-NAT TILs had this capacity for the prognosis of TN tumours. We conclude that ER and PR expression may help predict response to NAT in HER2 and TN BC and should be taken into account in residual tumours. Also, changes observed in the phenotype after NAT suggest the need to reevaluate biomarkers in surviving residual tumour cells.

Survival differences between HER2-0 and HER2-low-expressing breast cancer - A meta-analysis of early breast cancer patients

BACKGROUND

HER2-low (human epidermal growth factor receptor 2) breast cancer takes up 40-50% in all breast cancer subtypes. The survival difference between HER2-low and HER2-zero breast cancers remain uncertain. Therefore, the aim of this study was to compare survival outcome of the two subtypes and to explore the impact of hormone receptor status.

METHODS

A comprehensive medical literature search was performed by searching PubMed, EMBASE, and the Cochrane Libraries up to August 2022. We included observational studies reporting hazard ratios (HRs) with corresponding 95% confidence intervals (CIs). The results of individual studies were pooled by random-effects models using Stata 16.0. Seventeen articles with a total of 78984 breast cancer patients were included in the meta-analysis.

RESULTS

We observed a statistically significant association between low HER2 expression and better breast cancer survival outcomes (OS: HR: 0.83; 95% confidence interval: 0.75, 0.90; DFS/RFS: HR: 0.83; 95% confidence interval: 0.75, 0.91). In a subgroup analysis, we found that HER2-low patients had better survival outcomes relative to hormone receptor-positive breast cancer patients (OS: HR: 0.87; 95% confidence interval: 0.81, 0.93; DFS/RFS: HR: 0.91; 95% confidence interval: 0.85, 0.96). Similarly, in triple-negative breast cancer patients, we also observed a positive association between HER2 low expression and better survival (OS: HR: 0.85; 95% confidence interval: 0.71, 0.98; DFS/RFS: HR: 0.85; 95% confidence interval: 0.74, 0.95).

CONCLUSIONS

Our study showed that HER2-low breast cancer had better survival outcomes compared to HER2 negative breast cancer in patients with early stage breast cancer, regardless of hormone receptor status.

REGISTRATION

This meta-analysis was registered with PROSPERO (CRD42022335704) on June 10, 2022.

AVAILABILITY OF DATA AND MATERIALS

All data generated or analysed during this study are included in this published article [and its supplementary information files].

The changes of subtype markers between first and second primary breast cancers

BACKGROUND

Previous studies investigated the changes of subtype markers [estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2)] in several clinical settings, but not for second primary breast cancer (SPBC) after first primary breast cancer (FPBC).

METHODS

A total of 15,390 patients with SPBC were preliminarily selected from the Surveillance, Epidemiology, and End Results Program, and 3777 patients with complete information on three subtype markers in both FPBC and SPBC were included in the final analyses. The changes of subtype markers and their prognostic implications and potential influential factors were well investigated.

RESULTS

The overall change rates of ER, PR, and HER2 between FPBC and SPBC were 23.0% (867/3777), 35.0% (1322/3777), and 18.3% (691/3777), respectively. Gains of ER, PR, and HER2 after negative index markers were 48.7% (364/748), 37.9% (418/1103), and 11.5% (370/3211), while losses of markers after positive index markers were 16.6% (503/3029), 33.8%(904/2674), and 56.7%(321/566). Loss of ER was significantly associated with increased mortality (18.1% vs. 7.9%, p < 0.001), while gain of ER was significantly associated with decreased mortality (11.5% vs. 23.2%, p < 0.001). Similar results were observed for changes of PR status. However, loss of HER2 was significantly associated with decreased mortality (8.7% vs. 16.3%, p = 0.014), and no significant association was observed between the gain of HER2 and the prognosis of SPBC. Multivariate competing risk analyses showed similar results. HER2 status in FPBC, chemotherapy, and radiotherapy was significantly associated with changes of ER/PR (all p < 0.05), and no available therapies associated with HER2 change.

CONCLUSION

The changes of subtype markers are observed in a considerable proportion of patients and has statistically significant prognostic implications. Biopsies should be taken as a routine procedure for better therapy management.

Clinical significance and prognostic value of receptor conversion after neoadjuvant chemotherapy in breast cancer patients

The hormone receptor (HR) status and human epidermal growth hormone receptor 2 (HER2) status of patients with breast cancer may change following neoadjuvant chemotherapy (NAC). We retrospectively analyzed the clinical data of 294 patients with stage II/III breast cancer to evaluate the clinical significance and prognostic value of receptor transformation after NAC in breast cancer patients. Pathological complete response after NAC was achieved in 10.7% of patients. HR, estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67 conversion rates were 9.2%, 6.5%, 13.0%, 4.4%, and 33.7%, respectively. Patients with stable HR (P = 0.01) and HER2 (P = 0.048) expression had more favorable overall survival (OS). Low or reduced Ki-67 expression was associated with better disease-free survival (DFS) (P < 0.001) and OS (P < 0.01). Multivariate analysis showed that the number of lymph nodes after NAC, HR conversion, and radiotherapy were independent prognostic factors for overall survival. HR conversion implied a higher risk of death [hazard ratio, 2.56 (95% confidence interval: 1.19-5.51); P = 0.016]. Patients with HR conversion after NAC who received endocrine therapy had better DFS (P = 0.674) and OS (P = 0.363) than those who did not receive endocrine therapy, even if the HR changed from positive to negative. In conclusion, pathological testing should be performed before and after NAC, and even patients with HR conversion after NAC might benefit from endocrine therapy.

Hormone Receptor and HER2 Status Switch in Non-pCR Breast Cancer Specimens after Neoadjuvant Therapy

Introduction

This project aimed to identify the frequency of a switch of hormone receptor (HR) and/or HER2 status after neoadjuvant chemotherapy (NAC) for early breast cancer.

Methods

Tumor samples from patients without pathological complete response (non-pCR) were evaluated. Pathological complete response (pCR) was defined as no invasive tumor in breast and lymph nodes (ypT0/is ypN0). HR and HER2 status determined before NAC was compared with the corresponding receptor status determined in the surgical specimen after NAC.

Results

245 consecutive patients with primary invasive breast cancer, treated with NAC with/without targeted therapy between January 1, 2016 and December 31, 2019, at the LMU Breast Center, Munich, Germany, were identified. In 128 patients (52%), surgery revealed non-pCR after completed NAC. In 35 cases (27%), a switch of either HR and/or HER2 status between the initial biopsy and the surgical specimen was detected. Twenty cases had a switch in HR status, while 15 cases had a switch in HER2 status.

Conclusion

In a substantial number (27%) of non-pCR cases, a switch in biomarker status after completed neoadjuvant treatment was detected. These results are consistent with prior evidence. Yet, routine reevaluation of HR and HER2 status is not recommended in guidelines so far. Future research needs to address the impact of HR and HER2 status switch on therapy adaptation and on subsequent patient outcome. Particularly, in view of the recent therapy advances, it will be critical to evaluate whether individualization of treatment concepts based on the biology of the non-pCR specimens is preferable to the initial therapy concept based on the pathology at primary diagnosis.

Biomarker Dynamics and Long-Term Treatment Outcomes in Breast Cancer Patients with Residual Cancer Burden after Neoadjuvant Therapy

A residual cancer burden after neoadjuvant therapy (NAT) for breast cancer (BC) is associated with worse treatment outcomes compared to patients who achieved pathologic complete remission. This single-institutional retrospective study of 767 consecutive patients, including 468 patients with assessable residual cancer burden (aRCB) after NAT, with a median follow-up of 36 months, evaluated the biomarkers assessed before NAT from a biopsy and after NAT from a surgical specimen, their dynamics, and effect on long-term outcomes in specific breast cancer subtypes. The leading focus was on proliferation index Ki-67, which was significantly altered by NAT in all BC subtypes (p < 0.001 for HER2 positive and luminal A/B HER2 negative and p = 0.001 for TNBC). Multivariable analysis showed pre-NAT and post-NAT Ki-67 as independent predictors of survival outcomes for luminal A/B HER2 negative subtype. For TNBC, post-NAT Ki-67 was significant alone, and, for HER2 positive, the only borderline association of pre-NAT Ki-67 was observed in relation to the overall survival. Steroid and HER2 receptors were re-assessed just in a portion of the patients with aRCB. The concordance of both assessments was 92.9% for ER status, 80.1% for PR, and 92.2% for HER2. In conclusion, these real-world data of a consecutive cohort confirmed the importance of biomarkers assessment in patients with aRCB, and the need to consider specific BC subtypes when interpreting their influence on prognosis.

HER2 changes to positive after neoadjuvant chemotherapy in breast cancer: A case report and literature review

BACKGROUND

As the most common cancer in women, breast cancer is the leading cause of death. Most patients are initially diagnosed as stage I-III. Among those without distant metastases, 64% are local tumors and 27% are regional tumors. Patients in stage IIA-IIIC and those who meet the breast-conserving criterion with the exception of tumor size can consider neoadjuvant chemotherapy (NACT). It is worth noting that the status of tumor cell biomarkers is not consistently static. Endocrine-related estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) encoded by erythroblastic leukemia viral oncogene homolog 2 gene can all alter from positive to negative or vice versa, especially in luminal B subtype after NACT. In addition, determination of HER2 status currently mainly relies on immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), but FISH is commonly used when the result of IHC is uncertain. HER2 is regarded as negative when the IHC result is 0/1+ without the addition of FISH. To the best of our knowledge, this is the first report of a case harboring HER2 status transformation and IHC1+ with positive amplification by FISH after NACT.

CASE SUMMARY

A 49-year-old woman discovered a mass in her right breast and underwent diagnostic workup. Biopsies of the right breast lesion and axillary lymph nodes were obtained. The results pointed to invasive ductal carcinoma with the IHC result for ER (80%), PR (60%), Ki-67 (20%) and ambiguous expression of HER2 (IHC 2+) with negative amplification by FISH (HER2/CEP17 ratio of 1.13). She underwent surgery after NACT. The pathological findings of the surgically resected sample supported invasive ductal carcinoma with the tumor measuring 1.1 cm × 0.8 cm × 0.5 cm and had spread to one of fifteen dissected lymph nodes. Retesting of the specimen showed that the tumor was positive for ER (2+, 85%) and PR (2+, 10%) but negative for HER2 by IHC (1+). Also Ki-67 had dropped to 2%. The patient was regularly monitored every 3 mo without evidence of recurrence.

CONCLUSION

Biomarker status should be reassessed after NACT especially in luminal subtypes.

Loss of HER2-positivity following neoadjuvant targeted therapy for breast cancer is not associated with inferior oncologic outcomes

BACKGROUND

Patients with human epidermal growth factor receptor 2 (HER2)-positive breast cancer are treated with trastuzumab-based neoadjuvant therapy (NAT); some patients with residual disease post-NAT show loss of HER2 amplification and has been inconsistently associated with oncologic outcomes.

METHODS

We queried our multi-institutional cancer registry for women with HER2-positive breast cancer undergoing NAT from 2011 to 2018. Clinicopathologic, treatment-related, and outcomes data were collected. Kaplan-Meier and Cox proportional hazards analysis were used to evaluate oncologic outcomes.

RESULTS

A total of 348 patients were identified; 166 (48%) had a pathologic complete response. Of the 182 patients with residual disease, 87 (48%) were HER2-positive, 34 (19%) were HER2-negative, and 61 (33%) were HER2-unknown, with a median follow-up of 44 months. There were no factors associated with HER2 loss apart from age. On Kaplan-Meier analysis, estimated 5-year recurrence-free survival (RFS) and overall survival (OS) for patients with HER2-positive residual disease was 81% and 92%, respectively, and 74% (log rank p = 0.75) and 81% (p = 0.35) in patients with HER2-negative residual disease.

CONCLUSION

The loss of HER2-positivity following NAT is not associated with worse 5-year RFS or OS. We do not recommend retesting HER2 status following NAT for the purpose of clinical management; these patients should complete targeted adjuvant therapy.

Concordance Between ER, PR, HER2 neu Receptors Before and After Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Background

Introducing neoadjuvant chemotherapy (NCT) in a breast cancer patient may be associated with changes in estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth hormone receptor 2 (HER2) status.

Method

In our prospective cohort study, we evaluated the impact of change in estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth hormone receptor 2 (HER2) on the prognosis of breast cancer patients treated with neoadjuvant chemotherapy (NCT). We investigated 110 patients with locally advanced breast cancer for ER, PR and HER2 status of their lesions before and after NCT.

Result

For hormone receptor status (HR) (which include ER, PR) of the residual tumor of the patients after receiving NCT, 12 (10.9%) of them changed from HR (+) to HR (−) and 15 (13.6%) changed from HR (−) to HR (+). For HER2 status after NCT, 8 (7.3%) patients changed from HER2 (+) to HER2 (−) and 9 (8.2%) patients changed from HER2 (−) to HER2 (+). Triple negative (TN) tumor phenotype changes occurred in 17 (15.5%) patients. Patients for whom the HR status changed from positive to negative had poor prognosis for both disease-free survival (DFS) and overall survival (OS) in univariate survival analysis.

Conclusion

Changes in ER, PR, HER2 status and tumor phenotype in breast cancer patients after NCT had a negative prognostic impact and were associated with a poor prognosis.

Alterations in Breast Cancer Biomarkers Following Neoadjuvant Therapy

INTRODUCTION

Biomarker changes in patients with residual disease (RD) after neoadjuvant systemic therapy (NAT) have unclear consequences. This study examined the prevalence of biomarker [hormone receptor (HR) and HER2] change and its effect on disease-free survival (DFS) and overall survival (OS).

PATIENTS AND METHODS

A total of 303 patients treated with NAT from 2008 to 2016 were identified from a prospective database. Biomarker status at diagnosis was determined and retested after NAT in patients with RD. DFS and OS were compared among three groups: no biomarker change, clinically insignificant change in either ER or PR without alteration in HR status, and clinically significant change in at least one biomarker with resultant change in HR or HER2 status. Subgroups with no change and HR change were examined [HR+HER2- no change, triple negative (TN) no change, HR+HER2- to TN, TN to HR+HER2].

RESULTS

Overall, 61.4% of patients had RD. Of these, 32.8% had changes in at least one biomarker. At median follow up of 5.48 years, no biomarker change was associated with improved DFS compared with changes in HR or HER2 status (p = 0.043). In addition, no biomarker change (p = 0.005) and clinically insignificant changes in biomarker status (p = 0.019) were associated with improved OS compared with clinically significant changes in HR or HER2 status. Among subgroups, HR+HER2- to TN was associated with worse DFS (p = 0.029) and OS (p = 0.008) compared with HR+HER2- no change.

CONCLUSIONS

Among those with RD, biomarker status change was common and impacted survival in subgroups of HR+ or TN disease. Retesting biomarkers after NAT has prognostic implications.

Prognostic significance of estrogen, progesterone and HER2 receptors' status conversion following neoadjuvant chemotherapy in patients with locally advanced breast cancer: Results from a tertiary Cancer Center in Saudi Arabia

Background

The prognostic impact of neoadjuvant chemotherapy (NAC) on the receptor expression status in patients with locally advanced breast cancer (LABC) is still not fully understood. We aimed to evaluate the changes in hormone (estrogen and progesterone) receptor (HR) and human epidermal growth factor receptor 2 (HER2) status post-NAC and their correlation with survival.

Methods

Patients with LABC who have received NAC between 2008 and 2015 and have been followed up till December 2019 at the Oncology Center, King Saud University, KSA were analyzed retrospectively. biomarker analysis of ER, PR & HER2 were done using immunohistochemistry (IHC) and Fluorescent in situ hybridization.

Results

Ninety-one patients fulfilled the inclusion criteria. HR status changed in 21(23.1%) patients, with a significant difference between patients with stable receptors and those with any receptor conversion; p = 0.000. Five (5.5%) initially HER2 negative tumors became HER2 positive and 10 (11%) initially HER2 positive tumors became HER2 negative after NAC. The difference in HER2 expression level before and after NAC was not statistically significant (p = 0.302). Univariate analysis relating patients’ characteristics and 10-years disease-free survival (DFS) showed only significant correlations with the expressions of ER, PR, and any receptor conversion, (ER and/or PR) p< 0.001, p< 0.001, and p = 0.001; respectively. In the univariate analysis, none of the clinicopathological features showed a significant correlation with the OS except for the molecular subtypes P<0.001.

Conclusions

Patients with LABC have significant changes in the ER and PR receptor status following NAC. Post-NAC expressions change of ER and PR (ER and/or PR) are correlated to DFS. Retesting of the hormone receptors should be considered after NAC in Saudi patients with LABC.

Hormone Receptor Loss in Breast Cancer: Molecular Mechanisms, Clinical Settings, and Therapeutic Implications

Hormone receptor-positive breast cancer (HR+ BC) accounts for approximately 75% of new BC diagnoses. Despite the undisputable progresses obtained in the treatment of HR+ BC in recent years, primary or acquired resistance to endocrine therapies still represents a clinically relevant issue, and is largely responsible for disease recurrence after curative surgery, as well as for disease progression in the metastatic setting. Among the mechanisms causing primary or acquired resistance to endocrine therapies is the loss of estrogen/progesterone receptor expression, which could make BC cells independent of estrogen stimulation and, consequently, resistant to estrogen deprivation or the pharmacological inhibition of estrogen receptors. This review aims at discussing the molecular mechanisms and the clinical implications of HR loss as a result of the therapies used in the neoadjuvant setting or for the treatment of advanced disease in HR+ BC patients.

Prognostic Significance of HER2 Expression Changes Following Neoadjuvant Chemotherapy in Saudi Patients With Locally Advanced Breast Cancer

BACKGROUND

Progesterone receptor (PR), estrogen receptor (ER), and human epidermal growth factor receptor 2 (HER2) significantly influence disease prognosis and therapeutic response in patients with breast cancer. Neoadjuvant chemotherapy (NACT) can change the receptor status, affecting the disease characteristics.

PATIENTS AND METHODS

A retrospective chart review was carried out at a single tertiary care hospital in Riyadh, Kingdom of Saudi Arabia, from December 2008 to December 2014, where 91 adult female patients diagnosed with locally advanced breast cancer planning to receive NACT were included. Original pathology and surgical histopathology reports were assessed, and patients were followed up to recurrence, death, or until December 2019. An expression for the ER, PR, and HER2 was carried out in pre and post NACT specimens by an experienced pathologist, and all HER2 with 2+ immunohistochemistry was sent for fluorescence in situ hybridization as per American Society of Clinical Oncology guidelines.

RESULTS

ER pre- and postoperatively changed from positive to negative in 17.6% of patients and from negative to positive in 1.1% of patients (P < .001). ER status remained stable in 81.3% of patients. PR changed from positive to negative in 13.2% of patients, and from negative to positive in 3.3% of patients (P < .001), whereas it remained stable in 83.5% of patients. HER2 changed from positive to negative in 11% of patients, and from negative to positive in 5.5% of patients (P < .001), and it remained stable in 83.5% of patients. No significant association was found between overall survival and disease-free-survival with HER2 expression change.

CONCLUSION

NACT can induce changes in the ER, PR, and HER2 status, which should be evaluated post-NACT to choose the optimal treatment regimens.

Effect of neoadjuvant therapy on breast cancer biomarker profile

BACKGROUND

Breast cancer clinical management requires the assessment of hormone receptors (estrogen (ER) and progesterone receptor (PR)), human epidermal growth factor receptor 2 (HER2) and cellular proliferation index Ki67, by immunohistochemistry (IHC), in order to choose and guide therapy according to tumor biology. Many studies have reported contradictory results regarding changes in the biomarker profile after neoadjuvant therapy (NAT). Given its clinical implications for the disease management, we aimed to analyze changes in ER, PR, HER2, and Ki67 expression in paired core-needle biopsies and surgical samples in breast cancer patients that had either been treated or not with NAT.

METHODS

We included 139 patients with confirmed diagnosis of invasive ductal breast carcinoma from the Colombian National Cancer Institute. Variation in biomarker profile were assessed according to NAT administration (NAT and no-NAT treated cases) and NAT scheme (hormonal, cytotoxic, cytotoxic + trastuzumab, combined). Chi-squared and Wilcoxon signed-rank test were used to identify changes in biomarker status and percentage expression, respectively, in the corresponding groups.

RESULTS

We did not find any significant variations in biomarker status or expression values in the no-NAT group. In cases previously treated with NAT, we did find a statistically significant decrease in Ki67 (p < 0.001) and PR (p = 0.02605) expression. When changes were evaluated according to NAT scheme, we found a significant decrease in both Ki67 status (p = 0.02977) and its expression values (p < 0.001) in cases that received the cytotoxic treatment.

CONCLUSIONS

Our results suggest that PR and Ki67 expression can be altered by NAT administration, whereas cases not previously treated with NAT do not present IHC biomarker profile variations. The re-evaluation of these two biomarkers after NAT could provide valuable information regarding treatment response and prognosis for breast cancer patients.

HER2 status in breast cancer: changes in guidelines and complicating factors for interpretation

Human epidermal growth factor receptor 2 (HER2) protein overexpression and/or HER2 gene amplification is found in about 20% of invasive breast cancers. It is a sole predictive marker for treatment benefits from HER2 targeted therapy and thus, HER2 testing is a routine practice for newly diagnosed breast cancer in pathology. Currently, HER2 immunohistochemistry (IHC) is used for a screening test, and in situ hybridization is used as a confirmation test for HER2 IHC equivocal cases. Since the American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines on HER2 testing was first released in 2007, it has been updated to provide clear instructions for HER2 testing and accurate determination of HER2 status in breast cancer. During HER2 interpretation, some pitfalls such as intratumoral HER2 heterogeneity and increase in chromosome enumeration probe 17 signals may lead to inaccurate assessment of HER2 status. Moreover, HER2 status can be altered after neoadjuvant chemotherapy or during metastatic progression, due to biologic or methodologic issues. This review addresses recent updates of ASCO/CAP guidelines and factors complicating in the interpretation of HER2 status in breast cancers.

Predictive and Prognostic Roles of Pathological Indicators for Patients with Breast Cancer on Neoadjuvant Chemotherapy

Currently, neoadjuvant chemotherapy is a standard therapeutic strategy for breast cancer, as it can provide timely and individualized chemo-sensitivity information and is beneficial for custom-designing subsequent treatment strategies. To accurately select candidates for neoadjuvant chemotherapy, the association between various immunohistochemical biomarkers of primary disease and tumor response to neoadjuvant chemotherapy has been investigated, and results have shown that certain pathological indicators evaluated after neoadjuvant chemotherapy are associated with long-term prognosis. The Food and Drug Administration (FDA) has recommended that complete pathological response can be used as a surrogate endpoint for neoadjuvant chemotherapy, which is related to better prognosis. Considering that residual tumor persists in the majority of patients after neoadjuvant chemotherapy, the value of various pathological indicators of residual disease in predicting the long-term outcomes is being extensively investigated. This review summarizes and compares various predictive and prognostic indicators for patients who have received neoadjuvant chemotherapy, and analyzes their efficacy in different breast cancer subtypes.

Prognostic value of receptor status conversion following neoadjuvant chemotherapy in breast cancer patients: a systematic review and meta-analysis

Biomarkers of breast cancer such as hormone receptors (HR) and human epidermal growth factor 2 (HER2) can be altered after neoadjuvant chemotherapy (NAC). However, whether the conversion of these receptors affects the prognosis of patients remains to be determined. We sought to evaluate the prognostic value of HR and HER2 receptors before and after NAC and to analyze their clinical implications. Relevant studies were used to calculate the pooled hazard ratios, 95% confidence interval (95% CI). This meta-analysis included eight studies with 2847 patients. Compared to patients with HR+ → +, patients with HR+ → - have shorter disease free survival (DFS) (hazard ratio = 2.64, 95% CI 1.86-3.75) and overall survival (OS) (hazard ratio = 2.99, 95% CI 1.97-4.54). Furthermore, patients with HR- → + tend to achieve better DFS (hazard ratio = 0.83, 95% CI 0.60-1.17) compared to patients with HR- → -. Patients with HR- → + gain better OS (hazard ratio = 0.67, 95% CI 0.46-0.99) compared to patients exhibiting HR- → -. When comparing patients with HER2+ → - to patients with HER2+ → +, patients with HER2+ → - tended to achieve better DFS (hazard ratio = 1.65, 95% CI 1.08-2.53) though results for OS (hazard ratio = 1.16, 95% CI 0.54-2.49) were not statistically significant. Our data strongly support the need for redetection of HR and HER2 receptor status of surgical sample following neoadjuvant therapy. Changes in HR status induced by NAC can be used as a prognostic factor in breast cancer patients for predicting both OS and DFS. HER2 change may also be valuable for predicting prognosis. Further research should explore therapeutic strategies for those presenting receptor status conversion.

Breast Cancer Biomarkers: Challenges in Routine Estrogen Receptor, Progesterone Receptor, and HER2/neu Evaluation

Context.—

Evaluation of estrogen receptor (ER), progesterone receptor (PR), and HER2/neu (HER2) biomarkers is standard of care for all cases of newly diagnosed invasive, recurrent, and metastatic breast cancer. Repeat analysis is also performed in select cases per College of American Pathologists/American Society of Clinical Oncology guidelines and other clinical indications. However, in specific scenarios, preanalytic and analytic variables may pose distinct challenges to testing.

Objective.—

To provide a review of select challenges in the testing of commonly performed breast cancer biomarkers ER, PR, and HER2 and outline best practices for overcoming these challenges.

Data Sources.—

Review of College of American Pathologists/American Society of Clinical Oncology recommendations, current literature, and personal experience of the author.

Conclusions.—

Attention must be given to specimen handling to ensure accurate ER, PR, and HER2 biomarker assessment and appropriate management of breast cancer patients.

[Clinical challenges and implications of intratumor heterogeneity]

Tumors display a high, albeit variable, grade of intratumor heterogeneity, both from a clinical and a morphological viewpoint. Furthermore, recent methods of large-scale molecular analysis demonstrate to what extent tumors can also be heterogeneous from a molecular perspective. This is of paramount importance for patients as it has a great impact on the success of so-called precision therapies and explains the reason for a significant number of therapeutic failures in modern oncology. We present an up-to-date review of the latest findings in a group of tumors with a high social impact, commonly seen in the daily routine of the pathology laboratory.

Neutralization of BCL-2/XL Enhances the Cytotoxicity of T-DM1 In Vivo

One of the most recent advances in the treatment of HER2+ breast cancer is the development of the antibody-drug conjugate, T-DM1. T-DM1 has proven clinical benefits for patients with advanced and/or metastatic breast cancer who have progressed on prior HER2-targeted therapies. However, T-DM1 resistance ultimately occurs and represents a major obstacle in the effective treatment of this disease. Because anti-apoptotic BCL-2 family proteins can affect the threshold for induction of apoptosis and thus limit the effectiveness of the chemotherapeutic payload, we examined whether inhibition of BCL-2/XL would enhance the efficacy of T-DM1 in five HER2-expressing patient-derived breast cancer xenograft models. Inhibition of BCL-2/XL via navitoclax/ABT-263 significantly enhanced the cytotoxicity of T-DM1 in two of three models derived from advanced and treatment-exposed metastatic breast tumors. No additive effects of combined treatment were observed in the third metastatic tumor model, which was highly sensitive to T-DM1, as well as a primary treatment-exposed tumor, which was refractory to T-DM1. A fifth model, derived from a treatment naïve primary breast tumor, was sensitive to T-DM1 but markedly benefited from combination treatment. Notably, both PDXs that were highly responsive to the combination therapy expressed low HER2 protein levels and lacked ERBB2 amplification, suggesting that BCL-2/XL inhibition can enhance sensitivity of tumors with low HER2 expression. Toxicities associated with combined treatments were significantly ameliorated with intermittent ABT-263 dosing. Taken together, these studies provide evidence that T-DM1 cytotoxicity could be significantly enhanced via BCL-2/XL blockade and support clinical investigation of this combination beyond ERBB2-amplified and/or HER2-overexpressed tumors.

Pathologic complete response and overall survival in breast cancer subtypes in stage III inflammatory breast cancer

Purpose

To analyze the influence of hormone receptors (HR) and Human Epidermal growth factor Receptor-2 (HER2)-based molecular subtypes in stage III inflammatory breast cancer (IBC) on tumor characteristics, treatment, pathologic response to neoadjuvant chemotherapy (NACT), and overall survival (OS).

Methods

Patients with stage III IBC, diagnosed in the Netherlands between 2006 and 2015, were classified into four breast cancer subtypes: HR+/HER2− , HR+/HER2+ , HR−/HER2+ , and HR−/HER2− . Patient-, tumor- and treatment-related characteristics were compared. In case of NACT, pathologic complete response (pCR) was compared between subgroups. OS of the subtypes was compared using Kaplan–Meier curves and the log-rank test.

Results

1061 patients with stage III IBC were grouped into subtypes: HR+/HER2− (N = 453, 42.7%), HR−/HER2− (N = 258, 24.3%), HR−/HER2+ (N = 180,17.0%), and HR+/HER2+ (N = 170,16.0%). In total, 679 patients (85.0%) received NACT. In HR−/HER2+ tumors, pCR rate was highest (43%, (p < 0.001). In case of pCR, an improved survival was observed for all subtypes, especially for HR+/HER2+ and HR−/HER2+ tumor subtypes. Trimodality therapy (NACT, surgery, radiotherapy) improved 5-year OS as opposed to patients not receiving this regimen: HR+/HER2− (74.9 vs. 46.1%), HR+/HER2+ (80.4 vs. 52.6%), HR−/HER2+ (76.4 vs. 29.7%), HR−/HER2− (47.6 vs. 27.8%).

Conclusions

In stage III IBC, breast cancer subtypes based on the HR and HER2 receptor are important prognostic factors of response to NACT and OS. Patients with HR−/HER2− IBC were less likely to achieve pCR and had the worst OS, irrespective of receiving most optimal treatment regimen to date (trimodality therapy).

Real-world data on discordance between estrogen, progesterone, and HER2 receptor expression on diagnostic tumor biopsy versus tumor resection material

PURPOSE

The estrogen (ER), progesterone (PR), and HER2 status are essential in guiding treatment decisions in breast cancer patients. In daily life, the ER/PR/HER2 status is expected to be commonly tested twice, i.e., at diagnosis using material from tumor needle biopsies, and after tumor resection using full tumor tissue material. This study explored the discordance of ER/PR/HER2 between tumor needle biopsies and full tumor resection material using real-world patient-level data from Dutch breast cancer patients.

METHODS

Pathology reports of 11,054 breast cancer patients were derived from PALGA (Dutch Pathology Registry). Discordance was calculated for multiple combinations of the ER/PR/HER2 receptor status. The influence of patient and tumor characteristics on the probability of having discordant test results was analyzed using multiple logistic regression models (separately for ER, PR and HER2).

RESULTS

For 1279 patients (14.4%), at least one of the receptors (ER/PR/HER2) was determined on both biopsy and tumor tissue material. The majority had concordant test results for ER (n = 916; 94.8%), PR (n = 1170; 86.7%), and HER2 (n = 881; 98.1%). Patients having an ER- and HER2-positive but PR-negative biopsy classification, BR grade III, and < 10% tumor tissue remaining after neoadjuvant therapy (NAT) have the highest probability of ER discordant test results (OR 4.991; p = 83.31%). The probability of discordance in PR is based on different sets of patient and tumor characteristics. Potential cost savings from omitting multiple tests if concordance can be perfectly predicted can be up to €205,000 yearly.

CONCLUSIONS

Double testing of ER/PR/HER2 is less common than expected. Discordance in ER/PR/HER2 test results between tumor needle biopsy taken at the time of diagnosis and tumor resection material is very low, especially in patients not receiving any form of neoadjuvant therapy. These results imply that a substantial number of tests can potentially be omitted in specific subgroups of breast cancer patients.

Neoadjuvant chemotherapy reduces the expression rates of ER, PR, HER2, Ki67, and P53 of invasive ductal carcinoma

To analyze whether neoadjuvant chemotherapy (NAC) changes the expression rates of invasive ductal carcinoma (IDC) markers: estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), Ki67, and P53.This was a retrospective study of 112 IDC patients who underwent NAC (docetaxel+epirubicin/pirarubicin+cyclophosphamide) but without pathological complete response (pCR) in 2012 to 2013 at the First Affiliated Hospital of Chongqing Medical University. The IDC subtypes and tumor protein markers were analyzed by immunohistochemistry (IHC). Specific changes in tumor protein markers before/after NAC were compared.The decrease in the positive rate of Ki-67 was the most significant, from 75.9% before NAC to 41.1% after NAC (P < .001). The positive rate of HER2 decreased from 42.0% before NAC to 32.1% after NAC (P = .04). The positive rate of ER decreased from 66.1% before NAC to 56.2% after NAC (P = .04). Increased number of metastatic lymph nodes (P = .006) and body mass index (BMI) (P = .028) seemed to be related to conversion of PR (positive to negative). There was statistical association between the Ki-67 (positive to negative) with the age greater or equal to 50 (P = .015). The BMI greater or equal to 24 (P = .021), age greater or equal to 50 (P = .047), and blood type A (P = .038) were independently associated with conversion of P53 (positive to negative). The BMI greater or equal to 24 (P = .004), number of metastatic lymph nodes greater or equal to 1 (P = .029) and TNM stages I-II (P = .008) were statistically associated with change of HER2 (positive to negative).In patients without pCR, NAC leads to changes in Ki-67, HER2, and hormone receptor (HR) expression. Age, BMI, number of metastatic lymph nodes, and TNM stage are associated with some changes of markers.

Prognostic value of pathologic complete response and the alteration of breast cancer immunohistochemical biomarkers after neoadjuvant chemotherapy

Neoadjuvant chemotherapy(NCT) has become the standard treatment for breast cancer. The information about the tumor's sensitivity to chemotherapy and prognostic significance based on response to therapy can be provided after individualized neoadjuvant treatment. The biomarkers are key factors in the decision-making process regarding treatment as well as important prognostic indicators. Studies have shown that patients who achieve pathological complete response(pCR) after NCT have a better prognosis. For patients who do not achieve pCR, the pathological characteristics of the residual tumor can make an effect on the survival. Furthermore, the immunohistochemical (IHC) markers of the residual diseases after primary systemic therapy might be different from the primary tumor. Estrogen receptor (ER), progesterone receptor (PR), and Ki67 can usually change after NCT, while human epidermal growth factor receptor 2(HER2) seems to be more stable. The relationship between changes in breast cancer molecular biomarkers and the prognosis after neoadjuvant therapy is not yet clear. The article will make a review about it.

Delay to Formalin Fixation (Cold Ischemia Time) Effect on Breast Cancer Molecules

OBJECTIVES

The gold standard of examining breast biomarkers, including estrogen receptor (ER)/progesterone receptor (PR)/human epidermal growth factor receptor 2 (HER2)/Ki-67, is to perform these assays on formalin-fixed, paraffin-embedded tissue. However, preanalytical variables may confound these assays. One of these factors is delay to formalin fixation (DFF). The purpose of this review is to evaluate each study that investigated the effect of DFF on breast biomarkers and other molecules.

METHODS

Thirteen primary research articles were identified by the literature search. The credibility of the studies was judged based on the degree of controlling other confounding factors. Nine studies had a prospective design with a high number of controlled variables.

RESULTS

Most of the studies concluded that DFF had an effect on ER/PR/HER2. Some of these studies showed that DFF had negative effect on other markers used either clinically or for research purposes.

CONCLUSIONS

The vast majority of the studies agree that DFF has negative effect on breast biomarkers.

Effects of core needle biopsy and subsequent neoadjuvant chemotherapy on molecular alterations and outcome in breast cancer

Objectives

The aim of our study is to evaluate the effect of core needle biopsy (CNB) and subsequent neoadjuvant chemotherapy (NAC) on the expression of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth hormone receptor 2 (HER2) and Ki67 in breast cancer, and the associated influencing factors.

Materials and methods

In this retrospective cohort study, 143 patients with primary operable breast cancer who received NAC were included. ER, PR, HER2 and Ki67 statuses were compared between pretreatment and posttreatment residual samples. A control group of paired core and excision tumors from 123 patients who did not receive NAC within the same study period was also assessed. Data on patients’ clinicopathologic features were collected to identify associated influencing factors.

Results

Ki67 value significantly increased in excision tumors compared with paired core samples in controls without presurgery treatment (P<0.01), which was associated with the pathologic lymph node status and the interaction of PR and HER2 status (P=0.008 and 0.028, respectively). In 143 patients who underwent NAC, a significant decrease was observed in the expression of PR and Ki67 after NAC (P=0.003 and P<0.01, respectively). Further subgroup analysis showed that PR decrease was more obvious in premenopausal patients and Luminal A patients (P=0.006 and 0.002, respectively).

Conclusion

Core samples could provide more reliable information on determination of molecular subtype than surgical excisions. Decreases in PR and Ki67 expression following NAC could be used as positive prognostic factors. We recommend repeat testing of these biologic markers following NAC for the sake of better disease management. To the best of our knowledge, this is the most comprehensive study to analyze the effect of neoadjuvant chemotherapy on molecular alteration and its associated influencing factors after reporting a CNB-associated Ki67 increase in the same study.

Negative Conversion of Progesterone Receptor Status after Primary Systemic Therapy Is Associated with Poor Clinical Outcome in Patients with Breast Cancer

Purpose

Alteration of biomarker status after primary systemic therapy (PST) is occasionally found in breast cancer. This study was conducted to clarify the clinical implications of change of biomarker status in breast cancer patients treated with PST.

Materials and Methods

The pre-chemotherapeutic biopsy and post-chemotherapeutic resection specimens of 442 breast cancer patients who had residual disease after PST were included in this study. The association between changes of biomarker status after PST and clinicopathologic features of tumors, and survival of the patients, were analyzed.

Results

Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status changed after PST in 18 (4.1%), 80 (18.1%), and 15 (3.4%) patients,respectively. ER and PR mainly underwent positive to negative conversion,whereas HER2 status underwent negative to positive conversion. Negative conversion of ER and PR status after PST was associated with reduced disease-free survival. Moreover, a decline in the Allred score for PR in post-PST specimens was significantly associated with poor clinical outcome of the patients. HER2 change did not have prognostic significance. In multivariate analyses, negative PR status after PST was found to be an independent adverse prognostic factor in the whole patient group, in the adjuvant endocrine therapy-treated subgroup, and also in pre-PST PR positive subgroup.

Conclusion

ER and HER2 status changed little after PST, whereas PR status changed significantly. In particular, negative conversion of PR status was revealed as a poor prognostic indicator, suggesting that re-evaluation of basic biomarkers is mandatory in breast cancer after PST for proper management and prognostication of patients.

Neoadjuvant Chemotherapy Exerts Selection Pressure Towards Luminal Phenotype Breast Cancer

BACKGROUND

Breast cancer (BC) phenotype after neoadjuvant chemotherapy (NAC) has not been extensively described and few data exist on whether expression of the primary tumor hormone receptors, HER2 and Ki-67 changes as a result of chemotherapy.

MATERIALS AND METHODS

We analyzed specimens from all BC patients treated with anthracycline/taxane-based NAC at our Institution between January 2010 and March 2015 (n = 325). The expression of estrogen receptor (ER), progesterone receptor (PR), HER2 and Ki-67 was determined in pre- and post-NAC specimens. McNemar's test was used to compare paired proportions.

RESULTS

Among patients with residual disease after NAC, basal phenotype was luminal A, luminal B, HER2 positive and triple negative in 44, 111, 74 and 27 cases, respectively. PR-positive tumors decreased from 68.0% in the initial biopsy sample to 61.7% in the surgical specimen (p = 0.024). A Ki-67 of < 20% increased from 23.6% to 45% (p < 0.001). ER expression changed from positive to negative in 5% and from negative to positive in 16.7% of cases. Overall, 30% of cases underwent subtype changes, 79% of them towards luminal differentiation.

CONCLUSIONS

The switch towards luminal phenotype suggests some kind of endocrine effect of NAC. Our findings raise renewed interest in combinatorial cytotoxic chemotherapy with concomitant or rather sequential endocrine therapy, either alone or with targeted agents.

Reverse engineering of triple-negative breast cancer cells for targeted treatment

OBJECTIVE

Targeting the human epidermal growth factor receptor HER2 has increased survival in HER2-positive breast cancer patients. In the contrast, for triple-negative breast cancer (TNBC) patients, no targeted agents are available. We hypothesized that artificial overexpression of HER2 in TNBC cells might induce sensitivity to anti-HER2 agents in these cells.

METHODS

TNBC cell lines were transduced using lentiviral HER2 overexpression particles. Functionality of HER2 was determined by protein analysis and localization studies. The tumorigenic potential of HER2 overexpressing cells was assessed by analysis of proliferation, migration and invasion capacity. Response to chemotherapeutic agents and anti-HER2 agents was determined by cell viability assays.

RESULTS

We demonstrated functional overexpression of HER2 in TNBC cell lines of different subtypes. Whereas in cell types with more pronounced epithelial features (e.g. MDA-MB-468) HER2 overexpression increases proliferation and migration, in mesenchymal cell lines (MDA-MB-231 and BT-549) HER2 was able to further increase invasive potential. No changes were found in cancer stem cell characteristics or in response to chemotherapy, a trait of TNBC. When treated with anti-HER2 agents, however, HER2 overexpressing TNBC cells showed increased sensitivity to these agents.

CONCLUSION

This proof-of-principle study demonstrates that reverse engineering of TNBC cells might offer a novel targeted treatment strategy for this most aggressive subtype of breast cancer.

Epidemiology and survival outcome of breast cancer in a nationwide study

Breast cancer is among the most prevalent cancers in Taiwan. The National Health Insurance database was used to identify patients with breast cancer and estimate the yearly prevalence and incidence of breast cancer between 1997 and 2013. Joinpoint regression analysis was used for the annual percentage change of incidence, prevalence, and survival outcome. Among 12,181,919 female beneficiaries in 2013, the prevalence was 834.37 per 100,000 persons (95% confidence interval, 829.28–839.45) and the incidence was 93.00 per 100,000 person-year (95% confidence interval, 91.27–94.73). The average annual percentage change of the age-standardized breast cancer incidence was 3.5 per 100,000 person-years (3.1–3.8; P < 0.05), suggesting an increase in breast cancer incidence over the study period. The 5-year mortality rate was 4.5% in 1997 and 4.4% in 2008. The 5-year mortality rate among patients with Charlson comorbidity index > 1 was 39.1% (19.2%–59.1%) in 1997 and 21.1% (15.7%-32.0%) in 2008, with an annual percentage change of –0.8 (–1.3 to 2.9), suggesting that the mortality rate was gradually decreasing in patients with comorbidities. In conclusion, 1 in 120 women in Taiwan has breast cancer and the incidence is rising, while the annual percentage change of breast cancer prevalence is decreasing. The mortality rate of breast cancer was essentially stable, but the 1-year, 2-year, and 5-year mortality rates in people with Charlson comorbidity index > 1 were declined.

Adding Adjuvant Systemic Treatment after Neoadjuvant Therapy in Breast Cancer: Review of the Data

PURPOSE OF REVIEW

Residual disease after neoadjuvant chemotherapy is a poor prognostic factor; however, proven strategies to reduce recurrence risk and improve overall survival in this patient population are limited. Previous studies of residual disease have illustrated the importance of tumor intrinsic subtypes in treatment response and mechanisms of resistance. This review summarizes the rationale for various therapeutic approaches as well as completed and ongoing clinical trials for this high-risk group of patients.

RECENT FINDINGS

Regimens utilizing additional chemotherapy and targeted therapies (such as PARP inhibitors or bisphosphonates) have met with limited efficacy. Notably, a recently published randomized study of capecitabine in patients with residual disease demonstrated an improvement in disease-free survival and overall survival. While the results for capecitabine are promising, particularly for patients with triple-negative disease, the generalizability of these findings is an open question. Meanwhile, ongoing trials with novel agents that target specific tumor subtypes and the biology of residual disease may improve outcomes for other patient populations.

The ABC7 regimen: a new approach to metastatic breast cancer using seven common drugs to inhibit epithelial-to-mesenchymal transition and augment capecitabine efficacy

Breast cancer metastatic to bone has a poor prognosis despite recent advances in our understanding of the biology of both bone and breast cancer. This article presents a new approach, the ABC7 regimen (Adjuvant for Breast Cancer treatment using seven repurposed drugs), to metastatic breast cancer. ABC7 aims to defeat aspects of epithelial-to-mesenchymal transition (EMT) that lead to dissemination of breast cancer to bone. As add-on to current standard treatment with capecitabine, ABC7 uses ancillary attributes of seven already-marketed noncancer treatment drugs to stop both the natural EMT process inherent to breast cancer and the added EMT occurring as a response to current treatment modalities. Chemotherapy, radiation, and surgery provoke EMT in cancer generally and in breast cancer specifically. ABC7 uses standard doses of capecitabine as used in treating breast cancer today. In addition, ABC7 uses 1) an older psychiatric drug, quetiapine, to block RANK signaling; 2) pirfenidone, an anti-fibrosis drug to block TGF-beta signaling; 3) rifabutin, an antibiotic to block beta-catenin signaling; 4) metformin, a first-line antidiabetic drug to stimulate AMPK and inhibit mammalian target of rapamycin, (mTOR); 5) propranolol, a beta-blocker to block beta-adrenergic signaling; 6) agomelatine, a melatonergic antidepressant to stimulate M1 and M2 melatonergic receptors; and 7) ribavirin, an antiviral drug to prevent eIF4E phosphorylation. All these block the signaling pathways - RANK, TGF-beta, mTOR, beta-adrenergic receptors, and phosphorylated eIF4E - that have been shown to trigger EMT and enhance breast cancer growth and so are worthwhile targets to inhibit. Agonism at MT1 and MT2 melatonergic receptors has been shown to inhibit both breast cancer EMT and growth. This ensemble was designed to be safe and augment capecitabine efficacy. Given the expected outcome of metastatic breast cancer as it stands today, ABC7 warrants a cautious trial.

Alterations of biomarker profiles after neoadjuvant chemotherapy in breast cancer: tumor heterogeneity should be taken into consideration

Tumor biomarkers including estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and Ki-67 are routinely tested in breast cancer patients and their status guides clinical management and predicts prognosis. A few retrospective studies have suggested that neoadjuvant chemotherapy (NAC) in breast cancer may change the status of biomarker expression, which in turn will affect further management of these patients. In this study we take advantage of a relatively large cohort and aim to study the effect of NAC on biomarker expression and explore the impact of tumor size and lymph node involvement on biomarker status changes. We collected 107 patients with invasive breast cancer who received at least three cycles of NAC. We retrospectively performed and scored the immunohistochemistry (IHC) of ER, PR, HER2 and Ki-67 using both the diagnostic core biopsies before NAC and excisional specimens following NAC. HER2 gene status was assessed by fluorescence in situ hybridization for cases with IHC result of 2+. We demonstrated that there was a significant decrease in expression of PR (P = 0.013) and Ki-67 (P = 0.000) in post-NAC specimens compared to pre-NAC core biopsies. In addition, cases with large tumor size (≥2cm) and cases with lymph node metastasis were more frequently to have biomarker changes. Finally we studied cases with HER2 status changes after NAC treatments in detail and emphasized the nature of tumor heterogeneity.

Breast cancer biomarkers before and after neoadjuvant chemotherapy: does repeat testing impact therapeutic management?

In patients treated with neoadjuvant chemotherapy (NAC), there is no consensus on retesting biomarkers within the excision specimen. Our aim was to investigate the clinical relevance of biomarker changes post-NAC at a large tertiary medical center. A retrospective search was performed to identify cases from 2012 to 2015 with needle biopsy-confirmed invasive breast carcinoma treated with NAC and subsequent excision containing residual invasive tumor. Biomarkers (estrogen receptor [ER], progesterone receptor [PR], and HER2/neu [HER2]) were performed on all pre-NAC biopsies. One hundred fifty-four NAC-treated cases were identified in which 83 (54%) had repeat testing of at least 1 biomarker on the surgical specimen. Twenty-five (30%) of 83 repeated cases demonstrated changes in pre-NAC biopsy versus post-NAC resection biomarker status. There was no impact of age or grade on biomarker status changes. Tumors that were triple negative at biopsy were more likely to remain triple negative. Clinically relevant changes were identified including the following: (1) ER negative to ER positive, 2 (3%) of 75; (2) PR negative to PR positive with ER negative both pre- and post-NAC, 2 (3%) of 73; and (3) HER2 negative to positive, 1 (1%) of 77. Four of 5 of the changes led to modifications of the adjuvant treatment regimen, including the addition of adjuvant tamoxifen, anastrazole, or trastuzumab. In summary, post-NAC biomarker repeat testing in patients with breast cancer impacts therapeutic management in a small subset of patients and therefore, repeat testing may be considered for patients that are hormone receptor and/or HER2 negative before NAC.

Reproductive factors and hormone receptor status among very young (<35 years) breast cancer patients

The prognosis for breast cancer occurs in young women is usually poor. The impact of different reproductive factors on disease characteristics is still largely unknown. We analyzed 261 patients aged ≤35 years old who were treated at the Cancer Hospital of Fudan University, Shanghai, China. The relationships between certain reproductive factors (age at menarche, parity, number of children, breastfeeding, history of abortion, age at first full-term pregnancy and oral contraceptive (OC) use) and disease characteristics were evaluated. Compared with patients who experienced fewer full-term pregnancies (<2 times), the patients with more full-term pregnancies (≥2 times) exhibited higher percentage of ER-positive tumors (61.5%) (P = 0.015), and patients whose age of menarche was ≥15 years exhibited a greater chance of PR-positive tumors (64.8%) (P = 0.036) compared with those whose age of menarche was <15 years old. Additionally, patients who had taken OCs were more likely to present with late-stage tumors (II stage or later) (87.5%) (P = 0.002) than patients who had never taken OCs. Our study provides evidence that women with more full-term pregnancies and later age at menarche are more possible to exhibit hormone receptor-positive tumors. Additionally, patients who have taken OCs are more likely to present with advanced disease.