BREAst Cancer Personalised NuTrition (BREACPNT): dietary intervention in breast cancer survivors treated with endocrine therapy - a protocol for a randomised clinical trial

INTRODUCTION

Breast cancer survivors treated with adjuvant endocrine therapy commonly experience weight gain, which has been associated with low adherence to therapy and worse breast cancer prognosis. We aim to assess whether a personalised postprandial glucose targeting diet will be beneficial for weight management as compared with the recommended Mediterranean diet in this patient population METHODS AND ANALYSIS: The BREAst Cancer Personalised NuTrition study is a phase-2 randomised trial in hormone receptor positive patients with breast cancer, treated with adjuvant endocrine therapy. The study objective is to assess whether dietary intervention intended to improve postprandial glycaemic response to meals results in better weight and glycaemic control in this population as compared with the standard recommended Mediterranean diet. Consenting participants will be assigned in a single blinded fashion to either of two dietary arms (Mediterranean diet or an algorithm-based personalised diet). They will be asked to provide a stool sample for microbiome analysis and will undergo continuous glucose monitoring for 2 weeks, at the initiation and termination of the intervention period. Microbiome composition data will be used to tailor personal dietary recommendations. After randomisation and provision of dietary recommendations, participants will be asked to continuously log their diet and lifestyle activities on a designated smartphone application during the 6-month intervention period, during which they will be monthly monitored by a certified dietitian. Participants' clinical records will be followed twice yearly for 5 years for treatment adherence, disease-free survival and recurrence.

ETHICS AND DISSEMINATION

The study has been approved by the ethics committee in the Sheba medical centre (file 5725-18-SMC, Ramat Gan, Israel) and the Weizmann Institutional Review Board (file 693-2, Rehovot, Israel). The findings of this study will be published in a peer reviewed publication.

TRIAL REGISTRATION NUMBER

NCT04079270.

Abstract P1-08-25: Evaluating an ex vivo organ culture system for predicting response to neoadjuvant chemotherapy in breast cancer patients

Background. Neoadjuvant chemotherapy (NACT) is increasingly administered for high-risk breast cancer patients. Yet, oncologists lack an effective method for assessing response to treatment beyond clinicpathological features. Organ tissue slices freshly obtained from the tumor and incubated in appropriate media, recapitulate the tumor’s heterogeneity and may provide a superior ex-vivo model for predicting response/resistance to treatment. While these models were tested in metastatic tumors, no studies up to date have been reported in early breast cancer or for NACT. These tests have short turnaround time (7-9 days), critical for the neoadjuvant setting. Here we aimed to prove the feasibility of performing cResponse assay, an ex vivo organ culture (EVOC), on freshly derived pre-treatment core needle biopsies and to evaluate it as a tool for predicting response to NACT in breast cancer. Methods. Pre-treatment tumor biopsies were obtained from breast cancer patients about to undergo NACT at the time of routine tumor clip marking. The fresh samples were immediately placed in cold medium, sliced into 250um sections and cultured in multiwell plates. The samples were treated with the clinically administered therapies or a vehicle control. The various therapies included Doxorubicin (A), Paclitaxel (T), Cytoxan (C) and in TN cases, Carboplatin (Cr), as single agents or in combination in clinically administered ratios. After 4 days of treatment, tumor slices were fixed and stained to allow morphological analysis. A trained pathologist examined the stained slides and scored the viable cancer cells. A response-score was generated and compared to the pathological result (pCR status and RCB class) of the patient at surgery.Results. Tumor samples from 15 breast cancer patients were examined. The cohort median age was 42 (32—82), LN involvement 9/15, subtypes status: 9 HR+, 2 TNBC, 3 HR+HER2+ and 1 HR-HER2+. Nine samples were either excluded due to insufficient viable cancer cells or necrosis and one sample failed technically. Five samples (2 TNBC, 2 HR+ and 1 HR+HER2+) were adequate for analysis and obtained cResponse scores. The HR+HER2+ case received a different protocol than actually tested, thus was not compared. For the four successful cases, the cResponse score was highly concordant with response to therapy (Table I). For the two TNBC samples, a maximal cResponse score (100) was demonstrated for AC-T or AC-TC combination and both patients achieved complete response (pCR, RCB-0) at surgery. Notably, in one patient, the assay predicted maximal response for the TC combination, suggesting that this protocol could be sufficient. For the HR+ patients, one patient demonstrated a strong cResponse to AC-T (85) and achieved near complete response (RCB-I), while the second patient demonstrated a moderate cResponse score (70) and achieved partial pathological response (RCB-II). Conclusions. We provide initial evidence for the feasibility and validity of an EVOC platform to predict response to NACT in breast cancer. Further optimizations are needed to increase the assay’s success rates. We expect the results to set the ground for a clinical trial, examining the utility of the cResponse test as predictive biomarker in determining NACT. This technology may provide a tool for the oncologist to select the most efficient therapies, maximizing pCR rates and minimizing toxicity from ineffective drugs, eventually improving prognosis of breast cancer patients.

Table IPatientSubtypeBest cResponse scoreBest treatmentsPathological ResponseRCB classNAT-2HR+70AC-T/AC/CPartialRCB-IINAT-3TN100AC-TCr/TCrpCRRCB-0NAT-12TN100A/AC-TpCRRCB-0NAT-16HR+85AC-TPartialRCB-I

Citation Format: Einav Nili Gal-Yam, Miri Sklair-Levi, Yaeli Vachnish, Nora Balint-Lahat, Dana Morzaev-Sulzbach, Michal Bakalenik-Gavry, Renata Fearmann, Osnat Halshtok, Anat Shalmon, Michael Gotlieb, Yael Yagil, Keren Levanon, Rinat Bernstein-Molho, Amit Itay, Tali Shapira-Rotenberg, Opher Globus, Iris Barshack, Seth Salpeter, Vered Bar, Sara Aharon, Lubov Turovsky, Adi Zundelevich, Giuseppe Mallel, Hamutal Shahar, Hagit Shapira, Maya Dadiani. Evaluating an ex vivo organ culture system for predicting response to neoadjuvant chemotherapy in breast cancer patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P1-08-25.

Chemotherapy Shifts the Balance in Favor of CD8+ TNFR2+ TILs in Triple-Negative Breast Tumors

Triple-negative breast cancer (TNBC) is primarily treated via chemotherapy; in parallel, efforts are made to introduce immunotherapies into TNBC treatment. CD4+ TNFR2+ lymphocytes were reported as Tregs that contribute to tumor progression. However, our published study indicated that TNFR2+ tumor-infiltrating lymphocytes (TNFR2+ TILs) were associated with improved survival in TNBC patient tumors. Based on our analyses of the contents of CD4+ and CD8+ TILs in TNBC patient tumors, in the current study, we determined the impact of chemotherapy on CD4+ and CD8+ TIL subsets in TNBC mouse tumors. We found that chemotherapy led to (1) a reduction in CD4+ TNFR2+ FOXP3+ TILs, indicating that chemotherapy decreased the content of CD4+ TNFR2+ Tregs, and (2) an elevation in CD8+ TNFR2+ and CD8+ TNFR2+ PD-1+ TILs; high levels of these two subsets were significantly associated with reduced tumor growth. In spleens of tumor-bearing mice, chemotherapy down-regulated CD4+ TNFR2+ FOXP3+ cells but the subset of CD8+ TNFR2+ PD-1+ was not present prior to chemotherapy and was not increased by the treatment. Thus, our data suggest that chemotherapy promotes the proportion of protective CD8+ TNFR2+ TILs and that, unlike other cancer types, therapeutic strategies directed against TNFR2 may be detrimental in TNBC.

The predictive potential of the spatial signature of lymphocytes in breast cancer patients

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Background: Tumor-infiltrating lymphocytes in breast cancer have emerged as both a prognostic and a potentially predictive immunotherapy biomarker. Advancements in artificial intelligence can extract pathology-based spatial immune fingerprints for use as treatment decision support tools. Methods: We examined 908 primary breast cancer patients with whole slide images (WSI) available from TCGA database. Digital structuring of WSIs included automated detection of lymphocytes, tumor and tumor adjacent stroma, using deep learning-based semantic segmentation. Prognosis was defined as progression free interval (PFI). A Cox Survival analysis was used to detect prognostic spatial features. We used principal component analysis (PCA) to reduce and decorrelate significant features. The resulting PCA features were used to fit the final model. The model was then validated on an independent database of WSI of breast lumpectomies, from two tertiary hospitals in Israel. Results: The analysis included 908 WSI. The average age was 58.4 years old, with a majority of early stage breast cancer (76.7%, stage I and II). The detection performance for tumor area and lymphocytes reached F1 scores of 99% and 97% respectively, in comparison to human annotation. In the Kaplan Meier (KM) analysis of 414 early stage luminal breast cancers, a high number of lymphocyte clusters (LC) and a high ratio between stromal lymphocyte density and tumor lymphocyte density (LD-S/LD-T) were significantly associated with longer PFI (p = 0.005 and p = 0.038, respectively). Based on these features, two continuous PCA features were added to the multivariate model, and remained significantly associated with PFI after adjusting for age (HR = 1.19, 95% CI 1.05-1.35; HR = 1.26 95% CI 1.03-1.55). The validation set was underpowered (n = 79) and data is still being collected. In a preliminary KM analysis of 37 early stage luminal breast cancer cases from the validation set, LD-S/LD-T was significantly associated with longer PFI (p = 0.046). Conclusions: In our study, LC and LD-S/LD-T, presumably surrogate measures of peritumoral lymphocytes, were found significantly associated with longer PFI.

TNFR2+ TILs are significantly associated with improved survival in triple-negative breast cancer patients

In view of the relatively limited efficacy of immunotherapies targeting the PD-1-PD-L1 axis in triple-negative breast cancer (TNBC) and of published reports on tumor-promoting roles of TNFR2+ tumor-infiltrating lymphocytes (TNFR2+ TILs), we determined the incidence of TNFR2+ TILs in TNBC patient tumors, their association with disease outcome and relations with PD-1+ TILs. Using a cohort of treatment-naïve TNBC patients with long follow-up (n = 70), we determined the presence of TNFR2+ TILs and PD-1+ TILs by immunohistochemistry. TILs (≥ 1% of cellular mass) and TNFR2+ TILs (≥ 1% of total TILs) were detected in 96% and 74% of tumors, respectively. The presence of TILs at > 5% of tumor cell mass ("Positive TILs"), as well as of positive TNFR2+ TILs (> 5%), was independently associated with good prognosis, and combination of both parameters demonstrated superior outcome relative to their lower levels. PD1+ TILs (> 5/hot spot) were detected in 63% of patients. High levels of PD-1+ TILs (> 20/hot spot) showed an unfavorable disease outcome, and in their presence, the favorable outcome of positive TNFR2+ TILs was ablated. Thus, TNFR2+ TILs are strongly connected to improved prognosis in TNBC; these findings suggest that TNFR2+ TILs have favorable effects in TNBC patients, unlike the tumor-promoting roles attributed to them in other cancer systems. Overall, our observations propose that the TNFR2+ TIL subset should not be targeted in the course of TNBC therapy; rather, its beneficial impacts may become into power when anti-PD-1 regimens-that may potentiate immune activities-are administered to TNBC patients.