Neoadjuvant endocrine therapy for luminal breast tumors: State of the art, challenges and future perspectives

Body mass index and clinical outcomes in breast cancer patients undergoing endocrine therapy: A meta-analysis and Mendelian randomization study

OBJECTIVE

The relationship between breast cancer prognosis, Body Mass Index (BMI), and endocrine therapy outcomes remains inconclusive. This study examines BMI's impact on survival outcomes in breast cancer patients receiving endocrine therapy through Mendelian randomization (MR) and a comprehensive clinical data review.

METHODS

A meta-analysis of clinical studies up to January 2024 investigated the association between obesity and the efficacy and safety of endocrine therapy. Additionally, a two-sample MR approach using genetic variants evaluated the causal effect of BMI on survival in breast cancer patients undergoing endocrine therapy.

RESULTS

Meta-analysis of eight studies (n = 12,673) found that BMI generally does not affect therapy outcomes. However, subgroup analysis showed that overweight patients on anastrozole had shorter disease-free survival (DFS) than normal-weight patients (Hazard Ratio (HR) = 1.21, P = 0.03), increased fatigue (Risk Ratio (RR) = 0.91, P = 0.03), and higher nausea with cyclin-dependent kinase 4/6(CDK4/6)inhibitors (Risk Ratio, RR = 0.69, P < 0.0001). Normal-weight patients on tamoxifen had a greater risk of bone pain (RR = 1.25, P = 0.03). Further MR analysis revealed no causal link between BMI and 5-year or 15-year survival rates in endocrine-treated patients (5-year HR = 0.7923, 95 % Confidence Interval (CI)[0.2053, 3.0581], P = 0.7355; 15-year HR = 0.9793, 95 % CI [0.7121, 1.3469], P = 0.898).

CONCLUSION

Current meta-analysis and MR findings suggest no significant link between BMI and the overall efficacy of endocrine therapy in breast cancer. However, BMI should be considered in anastrozole therapy due to differential effects on DFS and adverse events.

Molecular characterisation of the residual disease after neoadjuvant endocrine therapy in ER+/HER2- breast cancer uncovers biomarkers of tumour response

BACKGROUND

Neoadjuvant endocrine therapy (NET) in oestrogen receptor-positive /HER2-negative breast cancer (ER+/HER2- BC) allows real-time evaluation of treatment sensitivity by monitoring tumour response and offers the opportunity of personalised therapy. However, the lack of reproducible biomarkers to assess response and long-term prognosis after NET is a significant barrier to increase its indications.

METHODS

In this study we searched for clinically relevant molecular reporters of response to NET in a multicentre population of ER+/HER2- BC patients (n = 87) by using: PAM50 gene expression panel and immunohistochemical evaluation of key proteins involved in tumorigenesis.

RESULTS

Our PAM50 analyses show that tumours changing from luminal A to normal-like subtype after NET presented better radiological and pathological tumour responses, a significant larger decrease in Ki67 at surgery, lower preoperative endocrine prognostic index score (PEPI) and lower tumour cellularity size (TCS) than those with persistent luminal A status. Patients with the highest response to NET showed the largest decrease in PAM50-derived risk of recurrence (ROR) following NET. In addition, the percentage of p53 positive cells was associated with decreased response to NET.

CONCLUSIONS

Our findings highlight the change of intrinsic subtype from luminal A to normal-like after NET as a putative biomarker characterising the patient population that obtains the highest benefit from NET. Our study also suggests that changes in PAM50-derived ROR score and p53 evaluation could also help to identify those patients. Thus, this study uncovers potential biomarkers of response to NET and prognosis, which should be validated in independent cohorts, helping to the implementation of NET in the clinical practice.

Application status and research progress of targeted therapy drugs for hormone receptor-positive breast cancer

Breast cancer (BC) is the most common malignant tumor in women and the leading cause of cancer-related deaths in women. As one of the most common subtypes of breast cancer, patients with hormone receptor-positive (HR+) breast cancer usually experience disease progression over an extended period of time, triggering the search for therapeutic strategies other than endocrine therapy. In recent years, continuous research on various targets has led to dramatic changes in the treatment of hormone receptor-positive breast cancer patients, resulting in prolonged clinical survival. With the redefinition of human epidermal growth factor-2 (HER2) expression, more precise and individualized treatment is possible. This review comprehensively reviews targeted therapies and critical clinical trials for HR+ breast cancer and tracks the latest advances. It also provides valuable insights into the future direction of targeted therapies.

Relationship between the ultrasound features of different molecular subtypes of breast cancer and positive PD-1/PD-L1 expression

OBJECTIVES

To analyze differences in programmed cell death protein 1/ligand 1 (PD-1/PD-L1) expression, as well as the relationships between ultrasound/contrast-enhanced ultrasound characteristics and PD-1/PD-L1 expression, among invasive breast cancer molecular subtypes.

METHODS

The study included 172 invasive breast cancer patients with surgical resection and pathological confirmation at the First Affiliated Hospital of Xinjiang Medical University from June 2016 to April 2022. PD-1/PD-L1 expression was detected by immunohistochemistry. All patients underwent conventional ultrasound and some underwent contrast-enhanced ultrasound examination before resection.

RESULTS

PD-1 and PD-L1 were expressed in 112 and 121 cases, respectively. The luminal B and HER-2 subtypes had the lowest and highest PD-1 expression rates, respectively. The luminal B and triple-negative subtypes had the lowest and highest PD-L1 expression rates, respectively. Among 112 PD-1-positive cases, most luminal B cases exhibited ill-defined margins, while distant metastasis was more common in triple-negative cases. Among 121 PD-L1-positive cases, many HER-2-positive and triple-negative cases presented as large masses (diameter ≥ 2 cm), while luminal B cases were more likely to show calcification. Most luminal B PD-L1-positive cases displayed indistinct margins on contrast-enhanced ultrasound.

CONCLUSIONS

PD-1 expression differed among molecular subtypes of invasive breast cancer. Ultrasound/contrast-enhanced ultrasound features correlated with PD-1/PD-L1 expression in different breast cancer subtypes.

Neoadjuvant Radiotherapy and Endocrine Therapy for Oestrogen Receptor Positive Breast Cancers: The Neo-RT Feasibility Study

AIMS

To establish the safety and feasibility of delivering neoadjuvant radiotherapy and endocrine therapy for oestrogen receptor-positive breast cancers with palpable size 20mm or greater, for which radiotherapy might facilitate more conservative surgery.

MATERIALS AND METHODS

A single-arm feasibility study was conducted. Patients received whole breast radiotherapy with or without radiotherapy to nodal areas. Dose/fractionation was 40Gy in 15 fractions over 3 weeks, with or without either a simultaneous integrated boost to 48Gy or sequential boost to the tumour bed. This was followed by endocrine treatment for 20 weeks, then surgery. The primary endpoint of the study was the proportion of patients successfully completing neoadjuvant radiotherapy and endocrine treatment followed by breast surgery. Response and toxicity endpoints including mastectomy rate, peri/postoperative complications, and pathological response were also evaluated. The primary analysis is descriptive. The study regimen would be considered feasible if more than 70% of patients completed treatment, while it might not be considered feasible if less than 50% did so. With a one-sided 5% significance level and 80% power, a maximum of 43 patients would be required to detect a rate of ≤50% vs ≥70%.

RESULTS

14 patients were recruited out of the planned 43. Due to slow recruitment, particularly during the COVID-19 pandemic, the decision was made to stop the trial in October 2021. One registered patient was found to be ineligible before starting treatment. 13/13 patients (100%, 90% CI: 75.3%, 100%) who received any trial treatment successfully completed all trial treatments. The lower bound of the Clopper-Pearson (exact) 90% confidence interval was 79%, indicating that the primary endpoint would have been met if the planned recruitment had been achieved. 3/13 patients underwent mastectomy. 7/13 had more conservative surgery than had been planned at baseline. 4/13 patients experienced any peri/postoperative complication. The only acute radiotherapy toxicities reported were grade 1/2 dermatitis and grade 1 fatigue. Long-term breast outcomes were clinician assessed as none/mild at all timepoints in 12/13 patients. All tumours showed evidence of some pathological response to treatment, but none had a pathological complete response.

CONCLUSION

This treatment schedule is likely feasible. It is difficult to draw strong conclusions on safety/toxicity given the small numbers, but these seem in keeping with other recent reports of neoadjuvant breast radiotherapy.

Identifying predictors of treatment response and molecular changes induced by neoadjuvant chemotherapy and endocrine therapy in hormone receptor-positive/HER2-negative breast cancer: the NEOENDO translational study

BACKGROUND

Predictors of response to neoadjuvant chemotherapy (NACT) and endocrine therapy (NET) in hormone receptor-positive (HoR+)/human epidermal growth factor receptor 2 (HER2)-negative breast cancer (BC) are required. Also, pathological and molecular changes induced by both strategies and their impact on patients' outcomes have not been reported so far.

PATIENTS AND METHODS

In a cohort of 186 patients with early-stage HoR+/HER2-negative BC treated with NACT or NET, we assessed the association of baseline main clinicopathological features and PAM50 gene expression (GE), intrinsic subtypes (IS) and risk-of-relapse (ROR-P) score with pathological outcomes according to treatment strategy. Molecular NACT/NET-induced changes were described and compared, along with their associations with event-free survival (EFS). Comparison of the two cohorts after propensity score matching (PSM) was used as sensitivity analysis. Molecular changes were confirmed in cell lines.

RESULTS

NACT was associated with higher rates of residual cancer burden (RCB)-0/I than NET in the overall population (38.2% versus 13.5%, P < 0.001) and after PSM (P = 0.036). PAM50 non-luminal IS were the only independent and positive predictor of RCB-0/I (P = 0.024) in the NACT cohort, while MMP11 messenger RNA levels were the only independent and negative predictor (P = 0.014) in the NET cohort. Both treatments shifted the tumor types toward less aggressive forms (i.e. PAM50 luminal A/normal-like), lowered the risk of recurrence in terms of ROR-P, up-regulated selected immune genes and PAM50 basal-like-related genes/signature and significantly downregulated proliferation-/luminal-/HER2-related genes/signatures, though NACT more than NET. Molecular findings were confirmed after PSM. A net reduction in proliferation-related genes and ROR-P was confirmed in cell lines with chemotherapy and endocrine therapy. Different baseline molecular features associated with diverse kind of responses (ROR-P downstaging, Ki67 reduction or pathological responses) with NACT and NET. Decreasing ROR-P and transitioning the tumor subtype to resemble normal tissue (i.e. PAM50 normal-like) suggested improved EFS.

CONCLUSIONS

NACT was more effective in the molecular and dimensional tumor 'downstaging' than NET but baseline molecular features associated with differential responses according to treatment strategy. Examining baseline and post-treatment GE might help tailor more personalized and effective care.

Machine learning radiomics based on intra and peri tumor PA/US images distinguish between luminal and non-luminal tumors in breast cancers

PURPOSE

This study aimed to evaluate a radiomics model using Photoacoustic/ultrasound (PA/US) imaging at intra and peri-tumoral area to differentiate Luminal and non-Luminal breast cancer (BC) and to determine the optimal peritumoral area for accurate classification.

MATERIALS AND METHODS

From February 2022 to April 2024, this study continuously collected 322 patients at Shenzhen People's Hospital, using standardized conditions for PA/US imaging of BC. Regions of interest were delineated using ITK-SNAP, with peritumoral regions of 2 mm, 4 mm, and 6 mm automatically expanded using code from the Pyradiomic package. Feature extraction was subsequently performed using Pyradiomics. The study employed Z-score normalization, Spearman correlation for feature correlation, and LASSO regression for feature selection, validated through 10-fold cross-validation. The radiomics model integrated intra and peri-tumoral area, evaluated by receiver operating characteristic curve(ROC), Calibration and Decision Curve Analysis(DCA).

RESULTS

We extracted and selected features from intratumoral and peritumoral PA/US images regions at 2 mm, 4 mm, and 6 mm. The comprehensive radiomics model, integrating these regions, demonstrated enhanced diagnostic performance, especially the 4 mm model which showed the highest area under the curve(AUC):0.898(0.78-1.00) and comparably high accuracy (0.900) and sensitivity (0.937). This model outperformed the standalone clinical model and combined clinical-radiomics model in distinguishing between Luminal and non-Luminal BC, as evidenced in the test set results.

CONCLUSION

This study developed a radiomics model integrating intratumoral and peritumoral at 4 mm region PA/US model, enhancing the differentiation of Luminal from non-Luminal BC. It demonstrated the diagnostic utility of peritumoral characteristics, reducing the need for invasive biopsies and aiding chemotherapy planning, while emphasizing the importance of optimizing tumor surrounding size for improved model accuracy.

Prediction of response to neoadjuvant chemotherapy by MammaTyper® across breast cancer subtypes: A retrospective cross-sectional study

BACKGROUND

Neoadjuvant chemotherapy (NACT) is widely used in the treatment of triple-negative and HER2-positive breast cancer (BC), but its use in estrogen receptor (ER) and/or progesterone receptor (PR) positive/HER2-negative BC is questioned because of the low pathologic complete response (pCR) rates. This retrospective study assessed the mRNA-based MammaTyper® assay's capability of predicting pCR with NACT, and ER, PR, Ki67, and HER2 status at immunohistochemical (IHC) through transcriptomics.

METHODS

Diagnostic biopsies from 76 BC patients treated at the Cremona Hospital between 2012-2018 were analyzed. Relative mRNA expression levels of ERBB2, ESR1, PGR, and MKI67 were measured using the MammaTyper® kit and integrated into a pCR score. Predicting capability of pCR and standard IHC biomarkers could be assessed with ROC curves in 75 and 76 patients, respectively.

RESULTS

Overall, 68.0% patients obtained a MammaTyper® high-score and 32.0% a MammaTyper® low-score. Among high-score patients, 62.7% achieved pCR, compared to 16.7% in the low-score group (p = 0.0003). The binary MammaTyper® score showed good prediction of pCR in the overall cohort (area under curve [AUC] = 0.756) and in HR+/HER2-negative cases (AUC = 0.774). In cases with residual disease, the continuous MammaTyper® score correlated moderately with residual tumor size and decrease in tumor size. MammaTyper® showed substantial agreement with IHC for ESR1/ER and ERBB2/HER2, and moderate agreement for PGR/PR and MKI67/Ki67.

CONCLUSION

Overall, MammaTyper® pCR score may serve as a standardized tool for predicting NACT response in HR+/HER2-negative BC, potentially guiding treatment strategies. Additionally, it could provide a more standardized and reproducible assessment of ER, PR, HER2, and Ki67 status.

Unraveling the clinicopathological and molecular changes induced by neoadjuvant chemotherapy and endocrine therapy in hormone receptor-positive/HER2-low and HER2-0 breast cancer

BACKGROUND

The characterization and comparison of gene expression and intrinsic subtype (IS) changes induced by neoadjuvant chemotherapy (NACT) and endocrine therapy in hormone receptor-positive (HR+)/human epidermal growth factor receptor 2 (HER2)-low versus HR+/HER2-0 breast cancer (BC) has not been conducted so far. Most evidence on the association of HER2 status with pathologic responses and prognosis in HR+/HER2-negative BC is controversial and restricted to NACT-treated disease. Similarly, a temporal heterogeneity in HER2 status has been described only with NACT.

METHODS

We retrospectively recruited a consecutive cohort of 186 patients with stage I-IIIB HR+/HER2-negative BC treated with neoadjuvant therapy (NAT). Available diagnostic biopsies and surgical samples were characterized for main pathological features, PAM50 IS and ROR-P score, and gene expression. Associations with pathologic complete response, residual cancer burden-0/I, event-free survival (EFS) and overall survival (OS) based on HER2 status were assessed. Pre/post pathologic/molecular changes were analyzed in matched samples.

RESULTS

The HER2-low (62.9%) and HER2-0 (37.1%) cohorts did not differ significantly in main baseline features, treatments administered, breast-conserving surgery, pathologic complete response and residual cancer burden-0/I rates, EFS, and OS. NAT induced, regardless of HER2 status, a significant reduction of estrogen receptor/progesterone receptor and Ki67 levels, a down-regulation of PAM50 proliferation- and luminal-related genes/signatures, an up-regulation of selected immune genes, and a shift towards less aggressive IS and lower ROR-P. Moreover, 25% of HER2-0 changed to HER2-low and 34% HER2-low became HER2-0. HER2 shifts were significant after NACT (P < 0.001), not neoadjuvant endocrine therapy (P = 0.063), with consistent ERBB2 mRNA level dynamics. HER2 changes were not associated with EFS/OS.

CONCLUSIONS

HER2-low and HER2-0 status change after NAT in ∼30% of cases, mostly after NACT. Targeted adjuvant strategies should be investigated accordingly. Molecular downstaging with current chemo/endocrine agents and immunotherapy should not rely on HER2 immunohistochemical levels in HR+/HER2-negative BC. Instead, HER2-low-targeted approaches should be explored to pursue more effective and/or less toxic dimensional downstaging.

Radiological, pathological and surgical outcomes after neoadjuvant endocrine treatment in patients with ER-positive/HER2-negative breast cancer with a clinical high risk and a low-risk 70-gene signature

OBJECTIVE

This study aims to evaluate the response to and surgical benefits of neoadjuvant endocrine therapy (NET) in ER+/HER2-breast cancer patients who are clinically high risk, but genomic low risk according to the 70-gene signature (MammaPrint).

METHODS

Patients with ER+/HER2-invasive breast cancer with a clinical high risk according to MINDACT, who had a genomic low risk according to the 70-gene signature and were treated with NET between 2015 and 2023 in our center, were retrospectively analyzed. RECIST 1.1 criteria were used to assess radiological response using MRI or ultrasound. Surgical specimens were evaluated to assess pathological response. Two breast cancer surgeons independently scored the eligibility of breast conserving therapy (BCS) pre- and post- NET.

RESULTS

Of 72 included patients, 23 were premenopausal (100% started with tamoxifen of which 4 also received OFS) and 49 were postmenopausal (98% started with an aromatase inhibitor). Overall, 8 (11%) showed radiological complete response. Only 1 (1.4%) patient had a pathological complete response (RCB-0) and 68 (94.4%) had a pathological partial response (RCB-1 or RCB-2). Among the 26 patients initially considered for mastectomy, 14 (53.8%) underwent successful BCS. In all 20 clinical node-positive patients, a marked axillary lymph node was removed to assess response. Four out of 20 (20%) patients had a pathological complete response of the axilla.

CONCLUSION

The study showed that a subgroup of patients with a clinical high risk and a genomic low risk ER+/HER2-breast cancer benefits from NET resulting in BCS instead of a mastectomy. Additionally, NET may enable de-escalation in axillary treatment.

Cyclin-Dependent Kinase 4/6 Inhibitors Plus Endocrine Therapy versus Endocrine Therapy Alone for HR-Positive, HER-2-Negative Early Breast Cancer: Meta-Analysis of Phase III Randomized Clinical Trials

BACKGROUND

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors are approved for advanced breast cancer combined with endocrine therapy (ET). The efficacy of CDK4/6 inhibitors plus ET in hormone estrogen-positive, human epidermal growth factor 2-negative (HR+/HER2-) early-stage breast cancer (esBC) is still to be confirmed.

METHODS

We performed a systematic review and a meta-analysis to investigate the efficacy of CDK4/6i plus ET in esBC. Main outcomes included invasive disease-free survival (iDFS), distant relapse-free survival (DRFS), and overall survival (OS). We included only phase III randomized controlled trials. We used RStudio version 4.2.3, and we considered p < 0.05 to be statistically significant.

RESULTS

Four studies were selected, including 14,168 patients, of which 7089 were treated with CDK4/6i plus ET and 7079 received ET monotherapy. Regarding patient characteristics, 6828 (48.2%) were premenopausal. Compared with ET alone, iDFS rates (HR 0.81; 95% CI: 0.67, 0.98; p = 0.034) were significantly in favor of CDK4/6 inhibitors plus ET. However, there were no significant differences in DRFS (HR 0.79; 95% CI: 0.58, 1.07; p = 0.132) nor OS (HR 0.96; 95% CI: 0.69, 1.35; p = 0.829).

CONCLUSIONS

Our results show that the addition of CDK4/6 inhibitors is associated with a significant benefit for HR+/HER2- esBC patients in iDFS. More studies and longer follow-up are needed to assess overall survival benefits.

Case report: Primary CDK4/6 inhibitor and endocrine therapy in locally advanced breast cancer and its effect on gut and intratumoral microbiota

Locally advanced breast cancer poses significant challenges to the multidisciplinary team, in particular with hormone receptor (HR) positive, HER2-negative tumors that classically yield lower pathological complete responses with chemotherapy. The increasingly significant use of CDK 4/6 inhibitors (CDK4/6i) plus endocrine therapy (ET) in different breast cancer settings has led to clinical trials focusing on this strategy as a primary treatment, with promising results. The impact of the microbiota on cancer, and vice-versa, is an emerging topic in oncology. The authors report a clinical case of a postmenopausal female patient with an invasive breast carcinoma of the right breast, Luminal B-like, staged as cT4cN3M0 (IIIB). Since the lesion was considered primarily inoperable, the patient started letrozole and ribociclib. Following 6 months of systemic therapy, the clinical response was significant, and surgery with curative intent was performed. The final staging was ypT3ypN2aM0, R1, and the patient started adjuvant letrozole and radiotherapy. This case provides important insights on primary CDK4/6i plus ET in locally advanced unresectable HR+/HER2- breast cancer and its potential implications in disease management further ahead. The patient's gut microbiota was analyzed throughout the disease course and therapeutic approach, evidencing a shift in gut microbial dominance from Firmicutes to Bacteroidetes and a loss of microbial diversity following 6 months of systemic therapy. The analysis of the intratumoral microbiota from the surgical specimen revealed high microbial dissimilarity between the residual tumor and respective margins.

Chemotherapy combined with endocrine neoadjuvant therapy for hormone receptor-positive local advanced breast cancer: a case report and literature review

Background

Early studies have revealed antagonistic effects associated with stacking chemotherapy (CT) and endocrine therapy (ET), thereby conventional wisdom does not advocate the simultaneous combination of these two treatment modalities. Limited clinical studies exist on the combined use of neoadjuvant CT (NACT) and neoadjuvant ET (NET), and there are no reported instances of concurrent neoadjuvant treatment for locally advanced breast cancer (LABC) using capecitabine and fulvestrant (FUL).

Case presentation

We reported a 54-year-old woman who was diagnosed with hormone receptor-positive (HR+) LABC at our hospital. After neoadjuvant treatment involving two distinct CT regimens did not lead to tumor regression. Consequently, the patient was transitioned to concurrent capecitabine and FUL therapy. This change resulted in favorable pathological remission without any significant adverse events during treatment.

Conclusions

A novel approach involving concurrent neoadjuvant therapy with CT and endocrine therapy may offer a potentially effective treatment avenue for some cases with HR+ LABC.

Experimental Studies on the Therapeutic Potential of Vaccinium Berries in Breast Cancer-A Review

Breast cancer (BC) is the largest contributor to cancer deaths in women worldwide. Various parts of plants, including fruits, are known for their therapeutic properties and are used in traditional medicine. Fruit species exhibit anticancer activities due to the presence of bioactive natural compounds such as flavonoids and carotenoids. The Vaccinium spp. are fleshy berry-like drupes and are rich in bioactive compounds, with flavonols, flavanols, chalcones, and phenolic acids as the major groups of compounds. While there is clear evidence linking Vaccinium berries with a decreased risk of BC both in in vivo and in vitro experiments, the exact mechanisms involved in the protective effects of Vaccinium spp. rich extracts on BC cells are not fully understood. Thus, the purpose of this review is to highlight the mechanisms of action involved in the therapeutic potential of Vaccinium berries against BC in experimental models.

Ki-67 index after neoadjuvant endocrine therapy as a prognostic biomarker in patients with ER-positive/HER2-negative early breast cancer: a systematic review and meta-analysis

BACKGROUND

Neoadjuvant treatment discriminates responders, but pathologic complete response is uncommon in oestrogen receptor (ER)-positive/HER2-negative early breast cancer. We aimed to assess the prognostic value of Ki-67 index after neoadjuvant endocrine therapy (NET).

METHODS

We conducted a systematic literature search of PubMed, Embase, CENTRAL, and conference proceedings up to 22nd August 2023 to identify studies reporting the association of Ki-67 index after NET with recurrence-free survival (RFS) and/or overall survival (OS) in women with ER-positive/HER2-negative early breast cancer. We combined RFS and OS hazard ratios (HRs) with 95% confidence intervals (CIs).

RESULTS

Twelve studies including 7897 patients were analysed. Most studies were clinical trials (n = 7547) including only postmenopausal women (n = 3953) treated with aromatase inhibitor (n = 3359). Three studies evaluated Ki-67 in a preplanned core biopsy at 2-4 weeks of NET (n = 3348), while nine evaluated Ki-67 in the surgical specimen (n = 4549) after 2-24 weeks of NET. Median follow-up ranged between 37 and 95 months for RFS and 62-84 months for OS. High Ki-67 index after NET was significantly associated with worse RFS (HR 2.48, 95% CI 1.86-3.30) and OS (HR 2.66, 95% CI 1.65-4.28). A sensitivity analysis including three studies that measured Ki-67 in a preplanned core biopsy showed similar association with RFS (HR 2.41, 95% CI 1.77-3.30).

CONCLUSIONS

High Ki-67 after NET is associated with worse survival outcomes, even after a short course of NET, emphasising the prognostic value of this biomarker in women with ER-positive/HER2-negative early breast cancer.

The Role of Sentinel Lymph Node Biopsy in Breast Cancer Patients Who Become Clinically Node-Negative Following Neo-Adjuvant Chemotherapy: A Literature Review

BACKGROUND

In clinically node-positive (cN+) breast cancer (BC) patients who become clinically node-negative (cN0) following neoadjuvant chemotherapy (NACT), sentinel lymph node biopsy (SLNB) after lymphatic mapping with lymphoscintigraphy is not widely accepted; therefore, it has become a topic of international debate.

OBJECTIVE

Our literature review aims to evaluate the current use of this surgical practice in a clinical setting and focuses on several studies published in the last six years which have contributed to the assessment of the feasibility and accuracy of this practice, highlighting its importance and oncological safety. We have considered the advantages and disadvantages of this technique compared to other suggested methods and strategies. We also evaluated the role of local irradiation therapy after SLNB and state-of-the-art SLN mapping in patients subjected to NACT.

METHODS

A comprehensive search of PubMed and Cochrane was conducted. All studies published in English from 2018 to August 2023 were evaluated.

RESULTS

Breast units are moving towards a de-escalation of axillary surgery, even in the NACT setting. The effects of these procedures on local irradiation are not very clear. Several studies have evaluated the oncological outcome of SLNB procedures. However, none of the alternative techniques proposed to lower the false negative rate (FNR) of SLNB are significant in terms of prognosis.

CONCLUSIONS

Based on these results, we can state that lymphatic mapping with SLNB in cN+ BC patients who become clinically node-negative (ycN0) following NACT is a safe procedure, with a good prognosis and low axillary failure rates.