Tumor sensitization to chemotherapy through a dietary intervention targeted on lipids

Malgré les avancées thérapeutiques récentes, un nombre significatif de patients décèdent de leur cancer suite au développement de métastases. Les molécules conventionnelles de chimiothérapie ont un rôle pivot à ce stade, mais leur efficacité qui est dépendante de la dose, est limitée par leur toxicité aux tissus non tumoraux, par manque de spécificité. L’enjeu est de développer des approches spécifiques qui augmentent la toxicité de ces molécules pour les tumeurs sans affecter les autres tissus. L’acide docosahexaènoïque (DHA) est capable d’augmenter la sensibilité des tumeurs à la chimiothérapie de façon spécifique sans sensibiliser les tissus non tumoraux. Ce travail de thèse présente 1) une synthèse des études existantes supportant cette hypothèse, 2) l’évaluation de la faisabilité d’une supplémentation orale en DHA au cours de la chimiothérapie chez des patientes présentant un cancer du sein métastasé, 3) l’exploration des mécanismes impliqués dans la sensibilisation spécifique des tumeurs, 4) l’effet du DHA sur la perte de poids en cours de traitement, et 5) le profil d’incorporation du DHA au niveau des tumeurs et la relation avec son taux plasmatique.Despite great therapeutic improvements, a significant proportion of patients still die from cancer, mainly because of the development of metastases. At this stage, treatments rely heavily on conventional chemotherapy, but their efficacy, which is dose-dependent, is limited by its toxicity to non-tumor tissues, as a result of their poor selectivity. The challenge is to develop approaches aimed at increasing chemotherapy cytotoxicity to tumor tissue while not affecting non-tumor tissues. Docosahexaenoic acid (DHA), a lipid of marine origin, has the potential to selectively sensitize tumor tissue to anticancer drugs without sensitizing nontumor tissues. This manuscript reports 1) a review of existing studies supporting this hypothesis, 2) an assessement of the feasiblility of supplementing breast cancer patients with DHA during an anthracycline-based chemotherapy for metastases, 3) an exploration of the mechanisms involved in the selective sensitization of tumors by DHA, 4) the effect of DHA on weight loss related to chemotherapy, and 5) the profile of DHA incorporation into tumor tissue and the relation with its level in plasma

Augmentation de la sensibilité des tumeurs à la chimiothérapie par manipulation nutritionnelle

Malgré les avancées thérapeutiques récentes, un nombre significatif de patients décèdent de leur cancer suite au développement de métastases. Les molécules conventionnelles de chimiothérapie ont un rôle pivot à ce stade, mais leur efficacité qui est dépendante de la dose, est limitée par leur toxicité aux tissus non tumoraux, par manque de spécificité. L enjeu est de développer des approches spécifiques qui augmentent la toxicité de ces molécules pour les tumeurs sans affecter les autres tissus. L acide docosahexaènoïque (DHA) est capable d augmenter la sensibilité des tumeurs à la chimiothérapie de façon spécifique sans sensibiliser les tissus non tumoraux. Ce travail de thèse présente 1) une synthèse des études existantes supportant cette hypothèse, 2) l évaluation de la faisabilité d une supplémentation orale en DHA au cours de la chimiothérapie chez des patientes présentant un cancer du sein métastasé, 3) l exploration des mécanismes impliqués dans la sensibilisation spécifique des tumeurs, 4) l effet du DHA sur la perte de poids en cours de traitement, et 5) le profil d incorporation du DHA au niveau des tumeurs et la relation avec son taux plasmatique.Despite great therapeutic improvements, a significant proportion of patients still die from cancer, mainly because of the development of metastases. At this stage, treatments rely heavily on conventional chemotherapy, but their efficacy, which is dose-dependent, is limited by its toxicity to non-tumor tissues, as a result of their poor selectivity. The challenge is to develop approaches aimed at increasing chemotherapy cytotoxicity to tumor tissue while not affecting non-tumor tissues. Docosahexaenoic acid (DHA), a lipid of marine origin, has the potential to selectively sensitize tumor tissue to anticancer drugs without sensitizing nontumor tissues. This manuscript reports 1) a review of existing studies supporting this hypothesis, 2) an assessement of the feasiblility of supplementing breast cancer patients with DHA during an anthracycline-based chemotherapy for metastases, 3) an exploration of the mechanisms involved in the selective sensitization of tumors by DHA, 4) the effect of DHA on weight loss related to chemotherapy, and 5) the profile of DHA incorporation into tumor tissue and the relation with its level in plasma.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

Sensibilisation de métastases de cancers du sein à la chimiothérapie de type FEC par une intervention nutritionnelle par l'acide docosahexaènoïque (DHA) (résultats d'un essai clinique de phase II)

TOURS-BU Médecine (372612103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Should a Multigene Signature be Used in all Luminal Early Breast Cancers

International audienceBackground: Multigene signatures refine the risk of recurrence and guide adjuvant chemotherapy decision in luminal breast cancers. The decision to perform the assay is highly variable among oncologists. In order to guide the appropriate clinical group in whom to perform a genomic signature, our study analyzed in a homogeneous cohort which clinical risk groups triggered the use of the PAM50-based signature and their concordance with the genomic risk. Methods: A real life cohort of 222 early breast cancer patients with hormone receptor positive and HER2 negative disease had a commercial PAM50-based assay (Prosigna®) performed at our institution. The assay provided the risk group, the 10-year risk of distant recurrence and the intrinsic molecular subtype of breast cancer. Results: Based on nodal involvement, Ki67, tumor grade, mitotic index, and tumor size, no clinical pattern could identify a specific genomic risk group. The discordance with the genomic risk was high in patients with clinical low risk tumors, both in node negative and node positive patients. Up to 60% of them had a 10% or more risk of distant recurrence. Moreover, we identified a subgroup of luminal A tumors with a high genomic risk of recurrence. Genomic risk and intrinsic subtype were strong determinants of chemotherapy decision. Conclusions: Clinical profiles could not reliably identify genomic risk groups and guide the decision to use a multigene signature. Significant discordance with the genomic risk was observed within low clinical risk and luminal A tumors

Proteomic profile of high-risk luminal A early breast cancers.

International audienceBackground: Breast cancer is a heterogeneous disease with a wide range of outcomes. Among the intrinsic breast cancer subtypes, luminal A tumors are considered to have a favorable prognosis. However, molecular studies characterizing the genomic landscape of luminal A tumors revealed a molecular heterogeneity within this subtype, which also translated to variability in survival. A better understanding of the biology of this tumor subgroup is therefore needed to determine the appropriate therapeutic strategy. The aims of the study were to determine the frequency of high-risk luminal A tumors in a real life cohort of early breast cancers and provide a proteomic characterization of this subgroup using a mass spectrometry approach. Methods: 222 early breast cancer patients with hormone receptor positive and HER2 negative tumors treated at our institution had a PAM50-based genomic assay Prosigna to estimate their risk of recurrence. This assay assigned each tumor sample to an intrinsic molecular subtype of breast cancer. Luminal A and B tumors were analyzed with MALDI mass spectrometry imaging combined with microproteomics, a spatially-resolved on-tissue shotgun proteomic technology, to determine the proteomic profiles of both cancer cells and stroma. Results: Among the 129 luminal A breast cancers identified in our cohort, 67 (51%) had a risk of distant recurrence of 10% or more (32% had a 10% to 15% risk, and 19% a risk greater than 15%). High-risk luminal A tumors had a distinctive proteomic profile compared to low-risk luminal A or to luminal B tumors. Overexpression of the methionine biosynthesis pathway was the main differential protein expression observed in cancer cells and stroma of high-risk luminal A. Inflammation mediated by chemokine and cytokine signaling pathway and integrin signaling were also overexpressed in high risk luminal A compared to luminal B. In the stroma of luminal B tumors, EGR signaling, Ras and FGF pathways and angiogenesis were overexpressed compared to high-risk luminal A tumors. Conclusions: Real life data showed a significant proportion of high-risk luminal A breast cancers. MALDI mass spectrometry proteomics revealed distinctive tumor and microenvironment profiles in this breast cancer subgroup

Fallopian tube lesions as potential precursors of early ovarian cancer: a comprehensive proteomic analysis

Abstract Ovarian cancer is the leading cause of death from gynecologic cancer worldwide. High-grade serous carcinoma (HGSC) is the most common and deadliest subtype of ovarian cancer. While the origin of ovarian tumors is still debated, it has been suggested that HGSC originates from cells in the fallopian tube epithelium (FTE), specifically the epithelial cells in the region of the tubal-peritoneal junction. Three main lesions, p53 signatures, STILs, and STICs, have been defined based on the immunohistochemistry (IHC) pattern of p53 and Ki67 markers and the architectural alterations of the cells, using the Sectioning and Extensively Examining the Fimbriated End Protocol. In this study, we performed an in-depth proteomic analysis of these pre-neoplastic epithelial lesions guided by mass spectrometry imaging and IHC. We evaluated specific markers related to each preneoplastic lesion. The study identified specific lesion markers, such as CAVIN1, Emilin2, and FBLN5. We also used SpiderMass technology to perform a lipidomic analysis and identified the specific presence of specific lipids signature including dietary Fatty acids precursors in lesions. Our study provides new insights into the molecular mechanisms underlying the progression of ovarian cancer and confirms the fimbria origin of HGSC

Atezolizumab and paclitaxel as first line therapy in advanced triple-negative breast cancer patients included in the French early access program

Abstract Following the results of the IMpassion130 trial, an early access program (EAP) was opened in France, allowing patients with PD-L1-positive advanced triple negative breast cancer (aTNBC) to receive a combination of paclitaxel and atezolizumab as first line therapy. This EAP was later discontinued when the IMpassion131 trial read out with negative results. We performed a retrospective multicentric analysis in patients who were prospectively enrolled in the French EAP. Efficacy and toxicity data were obtained on 64 patients treated from August 2019 to August 2020 in 10 French cancer centers. Median progression-free survival (PFS) and overall survival (OS) were 4.1 months (95% CI [3.0–5.8]) and 17.9 months (95% CI [12.4–NR]), respectively. The 6-months PFS rate was 28% (95% CI [16–40%]) (N = 18/64), while N = 33/64 patients (52%, 95% CI [38–63%]) experienced a tumor response. Exploratory subgroup analyses retrieved that corticosteroid use at inclusion in the EAP, before treatment initiation, was the only independent unfavorable prognostic factor for PFS (HR 2.7, 95% CI [1.3–5.6]). No new safety signal was observed. This real-life study, unique by its setting (EAP granted by anticipation and later withdrawn), suggests atezolizumab and paclitaxel has a limited efficacy in PD-L1-positive aTNBC, especially in patients receiving corticosteroids as comedication before treatment start

Determinants of DHA incorporation into tumor tissue during dietary DHA supplementation.

International audienceDocosahexaenoic acid (DHA), upon incorporation into tumor tissue, has the potential to sensitize tumors to the effects of chemotherapy or radiation therapy. Although DHA has usually been supplied to tumor tissue in the diet, appropriate dietary conditions required to obtain optimal tumor levels have not been established. Hence, we studied mammary tumor tissue responses in rats fed various durations and doses of DHA. Rats fed a palm oil enriched diet (diet 0) were switched to diets providing either 0.8 g DHA/day (diet 1) or 1.5 g DHA/day (diet 2). Tumor tissue fatty acid composition was analysed at baseline (diet 0), at weeks 1, 4 and 9 during diet 1 and at week 4 during diet 2. Dietary DHA supplementation differentially increased DHA within phospholipids (PL) and triacylglycerol (TAG) fractions in tumors. DHA level equilibrated between 2 and 4 weeks in PL while DHA increase was more progressive in TAG and did not reach a steady state. A higher dose of DHA further increased DHA content in tumor PL and TAG (P = 0.018 and P < 0.001, respectively). DHA concentration in plasma PL was positively correlated with DHA in tumor PL (r = 0.72; P = 0.0003) and TAG (r = 0.64; P = 0.003). We conclude that dietary DHA supplementation enhances tumor content of DHA in a time- and dose-dependent manner, and that the DHA level in plasma PL could be used as a proxy for tumor DHA. These findings have implications for dietary DHA supplementations in cancer patients