Neoadjuvant Therapy of Cyclin-Dependent Kinase 4/6 Inhibitors Combined with Endocrine Therapy in HR+/HER2- Breast Cancer: A Systematic Review and Meta-Analysis

Efficacy and safety of neoadjuvant therapy for HR-positive/HER2-negative early breast cancer: a Bayesian network meta-analysis

BACKGROUND

Neoadjuvant treatment for hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer is controversial and requires a comprehensive analysis for optimal therapy assessment. Therefore, a two-step Bayesian network meta-analysis (NMA) was performed to compare the efficacy and safety of different neoadjuvant regimens.

RESEARCH DESIGN AND METHODS

Phase II/III randomized clinical trials comparing various neoadjuvant therapies for HR+/HER2- breast cancer were included. NMA and pairwise meta-analyses were conducted using Stata (version 14), R (version 4.2.3), and Review Manager 5.4.

RESULTS

Twenty-eight studies (5,625 patients) were eligible. NMA of objective response rate (ORR) indicated the highest SUCRA for chemotherapy (CT) and chemotherapy with anthracycline (CT(A)). Pathologic complete response (PCR) NMA demonstrated significant PCR improvement with chemotherapy regimens containing programmed cell death protein-1 and programmed cell death ligand-1 inhibitors (PD-1i/PD-L1i) and poly ADP-ribose polymerase inhibitors (PARPi). Combined analysis considering both the ORR and safety highlighted CT(A)'s efficacy and toxicity balance.

CONCLUSIONS

CT(A) and CT showed improved ORR compared with alternative regimens. CT(A) combined with PD-1/PD-L1 or PARP inhibitors significantly increased PCR rates. Comprehensive assessment of both ORR and safety indicated that CT(A) represents an optimal neoadjuvant therapy for HR+/HER2- breast cancer, whereas AI + CDK4/6 inhibitors rank solely behind chemotherapy.

REGISTRATION

PROSPERO Registration: CRD42024538948. International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) registration number INPLASY202440092.

Case report: An ultrasound-based approach as an easy tool to evaluate hormone receptor-positive HER-2-negative breast cancer in advanced/metastatic settings: preliminary data of the Plus-ENDO study

Background

Hormone receptor-positive tumors are unlikely to exhibit a complete pathological tumor response. The association of CDK 4/6 inhibitor plus hormone therapy has changed this perspective.

Case presentation

In this study, we retrospectively reviewed the charts of patients with a diagnosis of luminal A/B advanced/metastatic tumors treated with a CDK 4/6 inhibitor-based therapy. In this part of the study, we present clinical and ultrasound evaluation. Eight female patients were considered eligible for the study aims. Three complete and five partial responses were reported, including a clinical tumor response of 50% or more in five out of nine assessed lesions (55%). All patients showed a response on ultrasound. The mean lesion size measured by ultrasound was 27.1 ± 15.02 mm (range, 6-47 mm) at the baseline; 16.08 ± 14.6 mm (range, 0-40 mm) after 4 months (T1); and 11.7 ± 12.9 mm (range, 0-30 mm) at the 6 months follow-up (T2). Two patients underwent surgery. The radiological complete response found confirmation in a pathological complete response, while the partial response matched a moderate residual disease.

Conclusion

The evaluation of breast cancer by ultrasound is basically informative of response and may be an easy and practical tool to monitor advanced tumors, especially in advanced/unfit patients who are reluctant to invasive exams.

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.

CD10 expression as a potential predictor of pathological complete response in ER-negative and triple-negative breast cancer patients treated with anthracycline-based neoadjuvant chemotherapy

BACKGROUND

Neoadjuvant chemotherapy (NCT) can induce a pathological complete response (pCR) in breast cancer patients, leading to improved outcomes. However, predicting which patients will achieve pCR remains a challenge. CD10, a myoepithelial marker, has shown diagnostic and prognostic value in metastatic tumors. Its potential as a predictor of chemosensitivity to anthracycline-based NCT in breast cancer is unknown.

AIM

This retrospective study aimed to investigate the potential of CD10 cancer cell expression as a predictive marker of chemosensitivity in breast cancers treated with anthracycline-based neoadjuvant chemotherapy.

METHODS

We analyzed 130 patients with invasive ductal carcinoma who received anthracycline-based NCT. CD10 expression was assessed by immunohistochemistry on pre-treatment biopsies. Statistical analysis evaluated the association between CD10 expression and pCR rates.

RESULTS

Univariate analysis revealed that ER-positive and CD10-negative tumors had lower pCR rates [OR 7.4830 (95% CI 2.7762-20.1699); p = 0.0001]. Multivariate analysis confirmed ER status as a strong predictor of poor response [OR 0.085 (95% CI 0.024-0.30); p < 0.001] and CD10 expression as a predictor of a favourable response [OR 0.11 (0.8-0.19); p = 0.049]. CD10 expression significantly predicted pCR in ER-negative cases [OR 0.1098 (0.0268-0.4503); p = 0.0022] and triple-negative breast cancer [OR 0.0966 (95% CI 0.0270-0.3462); p = 0.0003]. Concordance was observed between core biopsies and excised samples.

CONCLUSION

Positive CD10 cancer cell expression may predict increased response to anthracycline-based neoadjuvant chemotherapy in ER-negative and triple-negative breast cancer cases. Further research is needed to validate these findings in larger cohorts and determine the clinical utility of CD10 as a predictive marker.

Neoadjuvant nivolumab + palbociclib + anastrozole for oestrogen receptor-positive/human epidermal growth factor receptor 2-negative primary breast cancer: Results from CheckMate 7A8

BACKGROUND

Preclinical data suggest synergistic activity with the combination of programmed death-1 and cyclin-dependent kinase 4/6 blockade in oestrogen receptor-positive/human epidermal growth factor 2-negative (ER+/HER2-) breast cancer. The noncomparative phase 1b/2 CheckMate 7A8 study (NCT04075604) evaluated neoadjuvant treatment with nivolumab, palbociclib, and anastrozole in patients with ER+/HER2- breast cancer. Here, we report outcomes from the safety run-in phase.

METHODS

Patients with histologically confirmed, untreated ER+/HER2- breast cancer, primary tumour ≥2 cm, ECOG performance status ≤1, and eligible for post-treatment surgery received nivolumab 480 mg intravenously every 4 weeks, palbociclib 125 mg or 100 mg orally once daily for 3 weeks per cycle, and anastrozole 1 mg orally once daily for five 4-week cycles, or until disease progression. The primary endpoint was the proportion of patients with dose-limiting toxicities (DLTs) within 4 weeks of treatment initiation.

RESULTS

At safety data review, 21 patients were treated (palbociclib 125-mg group: n = 9; palbociclib 100-mg group: n = 12). DLTs were reported in 2 (22.2%) and 0 patients in the palbociclib 125-mg and 100-mg groups, respectively. Across both groups, 9 patients discontinued treatment due to toxicity (grade 3/4 hepatic adverse events [n = 6], grade 3 febrile neutropaenia [n = 1], grade 1 pneumonitis [n = 1], and grade 3 rash and grade 2 immune-mediated pneumonitis [n = 1]). Consequently, the study was closed early.

CONCLUSIONS

Neoadjuvant treatment with nivolumab, palbociclib, and anastrozole showed a high incidence of grade 3/4 hepatotoxicity and treatment discontinuation, indicating that this combination should not be further pursued for treatment of primary ER+/HER2- breast cancer.

Neoadjuvant docetaxel and capecitabine (TX) versus docetaxel and epirubicin (TE) for locally advanced or early her2-negative breast cancer: an open-label, randomized, multi-center, phase II Trial

PURPOSE

The combination of taxanes and anthracyclines is still the mainstay of chemotherapy for early breast cancer. Capecitabine is an active drug with a favorable toxicity profile, showing strong anti-tumor activity against metastatic breast cancer. This trial assessed the efficacy and safety of the TX regimen (docetaxel and capecitabine) and compared it with the TE (docetaxel and epirubicin) regimen in locally advanced or high risk early HER2-negative breast cancer.

PATIENTS AND METHODS

This randomized clinical trial was conducted at five academic centers in China. Eligible female patients were randomly assigned (1:1) to the TX (docetaxel 75 mg/m² d1 plus capecitabine 1000 mg/m² twice d1-14, q3w) or TE (docetaxel 75 mg/m² d1 plus epirubicin 75 mg/m² d1, q3w) groups for four cycles. The primary endpoint was a pathological complete response in the breast (pCR). Secondary endpoints included pCR in the breast and axilla, invasive disease-free survival (iDFS), overall survival (OS), and safety.

RESULTS

Between September 1, 2012, and December 31, 2018, 113 HER2-negative patients were randomly assigned to the study groups (TX: n = 54; TE: n = 59). In the primary endpoint analysis, 14 patients in the TX group achieved a pCR, and nine patients in the TE group achieved a pCR (25.9% vs. 15.3%), with a not significant difference of 10.6% (95% CI -6.0-27.3%; P = 0.241). In a subgroup with high Ki-67 score, TX increased the pCR rate by 24.2% (95% CI 2.2-46.1%; P = 0.029). At the end of the 69-month median follow-up period, both groups had equivalent iDFS and OS rates. TX was associated with a higher incidence of hand-foot syndrome and less alopecia, with a manageable toxicity profile.

CONCLUSION

The anthracycline-free TX regimen yielded comparable pCR and long-term survival rates to the TE regimen. Thus, this anthracycline-free regimen could be considered in selected patients.

TRIAL REGISTRATION

ACTRN12613000206729 on 21/02/2013, retrospectively registered.

Clinicopathological characteristics and loss of mismatch repair protein expression in Chinese upper tract urothelial carcinomas

Expression of DNA mismatch repair (MMR) protein (MLH1, PMS2, MSH2, and MSH6) in upper tract urothelial carcinoma (UTUC) has been explored in Western cohorts, but it is rarely reported in Eastern cohorts. We aimed to assess the loss of MMR protein expression among Chinese UTUC patients and study its clinicopathological implications. We enrolled 175 UTUC patients at our center and tested the expression of MMR proteins by immunohistochemistry. Then, we explored these patients' clinicopathological characteristics. We found loss of MMR proteins in 19 (10.9%) of 175 patients in our cohort (6 MSH2 and MSH6, 2 MSH6 alone, 6 MSH2 alone, 3 MLH1 and PMS2, and 2 PMS2 alone). Loss of MMR proteins was not a significant prognostic factor of relapse-free survival for these patients. In addition, patients with lower T stage or with bladder cancer history were more likely to have loss of MMR protein expression. At last, two metastatic patients (MSH2 and MSH6 loss; MSH2 loss) with loss of MMR protein experienced tumor recession after several cycles of anti-PD-1 immunotherapy. In conclusion, this is the largest Chinese UTUC cohort study to date that explores the loss of MMR protein expression. The rate of MMR loss observed was comparable to that in the Western UTUC cohort, supporting universal UTUC screening in China. Furthermore, a subset of advanced UTUCs with MMR protein loss are probably immunogenic, for whom single or combined immunotherapy may be potential therapeutic options in the future.