Patient-Reported Outcomes in OlympiA: A Phase III, Randomized, Placebo-Controlled Trial of Adjuvant Olaparib in gBRCA1/2 Mutations and High-Risk Human Epidermal Growth Factor Receptor 2-Negative Early Breast Cancer

PURPOSE

The OlympiA randomized phase III trial compared 1 year of olaparib (OL) or placebo (PL) as adjuvant therapy in patients with germline BRCA1/2, high-risk human epidermal growth factor receptor 2-negative early breast cancer after completing (neo)adjuvant chemotherapy ([N]ACT), surgery, and radiotherapy. The patient-reported outcome primary hypothesis was that OL-treated patients may experience greater fatigue during treatment.

METHODS

Data were collected before random assignment, and at 6, 12, 18, and 24 months. The primary end point was fatigue, measured with the Functional Assessment of Chronic Illness Therapy-Fatigue scale. Secondary end points, assessed with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, Core 30 item, included nausea and vomiting (NV), diarrhea, and multiple functional domains. Scores were compared between treatment groups using mixed model for repeated measures. Two-sided P values <.05 were statistically significant for the primary end point. All secondary end points were descriptive.

RESULTS

One thousand five hundred and thirty-eight patients (NACT: 746, ACT: 792) contributed to the analysis. Fatigue severity was statistically significantly greater for OL versus PL, but not clinically meaningfully different by prespecified criteria (≥3 points) at 6 months (diff OL v PL: NACT: -1.3 [95% CI, -2.4 to -0.2]; P = .022; ACT: -1.3 [95% CI, -2.3 to -0.2]; P = .017) and 12 months (NACT: -1.6 [95% CI, -2.8 to -0.3]; P = .017; ACT: -1.3 [95% CI, -2.4 to -0.2]; P = .025). There were no significant differences in fatigue severity between treatment groups at 18 and 24 months. NV severity was worse in patients treated with OL compared with PL at 6 months (NACT: 6.0 [95% CI, 4.1 to 8.0]; ACT: 5.3 [95% CI, 3.4 to 7.2]) and 12 months (NACT: 6.4 [95% CI, 4.4 to 8.3]; ACT: 4.5 [95% CI, 2.8 to 6.1]). During treatment, there were some clinically meaningful differences between groups for other symptoms but not for function subscales or global health status.

CONCLUSION

Treatment-emergent symptoms from OL were limited, generally resolving after treatment ended. OL- and PL-treated patients had similar functional scores, slowly improving during the 24 months after (N)ACT and there was no clinically meaningful persistence of fatigue severity in OL-treated patients.

TGF-β1 potentiates Vγ9Vδ2 T cell adoptive immunotherapy of cancer

Despite its role in cancer surveillance, adoptive immunotherapy using γδ T cells has achieved limited efficacy. To enhance trafficking to bone marrow, circulating Vγ9Vδ2 T cells are expanded in serum-free medium containing TGF-β1 and IL-2 (γδ[T2] cells) or medium containing IL-2 alone (γδ[2] cells, as the control). Unexpectedly, the yield and viability of γδ[T2] cells are also increased by TGF-β1, when compared to γδ[2] controls. γδ[T2] cells are less differentiated and yet display increased cytolytic activity, cytokine release, and antitumor activity in several leukemic and solid tumor models. Efficacy is further enhanced by cancer cell sensitization using aminobisphosphonates or Ara-C. A number of contributory effects of TGF-β are described, including prostaglandin E2 receptor downmodulation, TGF-β insensitivity, and upregulated integrin activity. Biological relevance is supported by the identification of a favorable γδ[T2] signature in acute myeloid leukemia (AML). Given their enhanced therapeutic activity and compatibility with allogeneic use, γδ[T2] cells warrant evaluation in cancer immunotherapy.

PARP inhibition enhances tumor cell-intrinsic immunity in ERCC1-deficient non-small cell lung cancer

The cyclic GMP-AMP synthase/stimulator of IFN genes (cGAS/STING) pathway detects cytosolic DNA to activate innate immune responses. Poly(ADP-ribose) polymerase inhibitors (PARPi) selectively target cancer cells with DNA repair deficiencies such as those caused by BRCA1 mutations or ERCC1 defects. Using isogenic cell lines and patient-derived samples, we showed that ERCC1-defective non-small cell lung cancer (NSCLC) cells exhibit an enhanced type I IFN transcriptomic signature and that low ERCC1 expression correlates with increased lymphocytic infiltration. We demonstrated that clinical PARPi, including olaparib and rucaparib, have cell-autonomous immunomodulatory properties in ERCC1-defective NSCLC and BRCA1-defective triple-negative breast cancer (TNBC) cells. Mechanistically, PARPi generated cytoplasmic chromatin fragments with characteristics of micronuclei; these were found to activate cGAS/STING, downstream type I IFN signaling, and CCL5 secretion. Importantly, these effects were suppressed in PARP1-null TNBC cells, suggesting that this phenotype resulted from an on-target effect of PARPi on PARP1. PARPi also potentiated IFN-γ-induced PD-L1 expression in NSCLC cell lines and in fresh patient tumor cells; this effect was enhanced in ERCC1-deficient contexts. Our data provide a preclinical rationale for using PARPi as immunomodulatory agents in appropriately molecularly selected populations.

Abstract 2986: E-cadherin/ROS1 inhibitor synthetic lethality in breast cancer

The E-cadherin (CDH1) tumour suppressor gene encodes a calcium-dependent cell-cell adhesion glycoprotein, which has roles in maintaining cell polarity, differentiation, cell migration and survival. E-cadherin dysfunction is a feature common to many epithelial tumours, with the highest incidence occurring in diffuse gastric cancer (50%) and lobular breast cancer (63%) and can occur via CDH1 mutation, deletion or epigenetic silencing. Although E-cadherin dysfunction is relatively common, precision medicine approaches that exploit this pathogenic alteration are not yet available. Using genetic and small-molecule perturbation screens in breast tumour cells with CRISPR-Cas9 engineered CDH1 mutations, we identified a synthetic lethal interaction between E-cadherin deficiency and inhibition of the tyrosine kinase ROS1. Using data from large-scale genetic screens in molecularly diverse breast tumour cell lines, we found that the E-cadherin/ROS1 synthetic lethality was not only robust in the face of considerable molecular heterogeneity but was also elicited with clinical ROS1 inhibitors including foretinib and crizotinib. ROS1 inhibitors induced mitotic abnormalities and multinucleation in E-cadherin defective cells, phenotypes that were associated with a defect in cytokinesis and aberrant p120-catenin phosphorylation and localisation. In vivo, ROS1 inhibitors produced profound anti-tumour effects in multiple, distinct, models of E-cadherin defective breast cancer. This data therefore provides the pre-clinical rationale for assessing ROS1 inhibitors such as the licensed drug crizotinib in appropriately stratified patients.

Citation Format: Ilirjana Bajrami, Rebecca Marlow, Marieke van de Ven, Rachel Brough, Helen N. Pemberton, Jessica Frankum, Fei Fei Song, Rumana Rafiq, Asha Konde, Malini Menon, James Campbell, Aditi Gulati, Rahul Kumar, Stephen J. Pettitt, Mark D. Gurden, Marta Llorca Cardenosa, Irene Chong, Patrycja Gazinska, Fredrik Wallberg, Elinor J. Sawyer, Lesley-Ann Martin, Mitch Dowsett, Spiros Linardopoulos, Colm Ryan, Patrick W. Derksen, Jos Jonkers, Andrew N.J. Tutt, Alan Ashworth, Christopher J. Lord. E-cadherin/ROS1 inhibitor synthetic lethality in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2986.

Abstract P1-07-03: Mesenchymal subtype negatively associates with the presence of immune infiltrates within a triple negative breast cancer classifier

Introduction: Lehmann and colleagues (Lehmann et al., 2011) devised a gene expression classification system for triple negative breast cancer (TNBC) consisting of seven subtypes—IM, BL1, BL2, LAR, M, MSL, and UNS (unselected). We (Ring et al., 2016) recently modified this original algorithm of 2188 gene subtyping into a 101-gene algorithm. In addition to a reduction of genes, the 101-gene algorithm has two methodological differences: first, the immunomodulatory (IM) signature was treated not as a subtype but rather as a binary feature of one of the other subtypes (e.g. BL1/IM+, LAR/IM-); second, when tumors—by a predefined correlation coefficient—showed traits of more than one subtype, both subtypes were reported as “dual subtypes.”

Aim: Our aim was to apply the 101-gene algorithm for TNBC subtyping and to establish the relation of TNBC subtypes with their IM-status across several independent data sets.

Methods: 951 patients from four independent TNBC cohorts with available gene expression data were analyzed by the 101-gene algorithm. Of these 848 were classified with at least one subtype.

Results: The distribution of the 5 TNBC subtypes in both single and dual subtypes was 47%,10%,15%,18%,11%, for BL1, BL2, LAR, M, and MSL respectively. The majority of cases gave only one subtype (572, 67%) with M (Mesenchymal) being 9% (n=54) of these. Given this frequency of 9% of M as a baseline, in the remaining 276 (33%) cases with dual subtypes, the expectation that M would be one of the two is 11% (64 subtype calls). However, M is one of the two of the dual subtypes at a much higher frequency of 40% (222 subtype calls, Chi-Squared, P&lt;0.0001). IM+ is a common feature across these cohorts (n=310 or 37%). When examining the IM feature within the patients exhibiting the M subtype as either a single subtype or one of the two dual subtypes (n=276, 33%), IM positive tumors are never of the M phenotype (Chi-Squared, p&lt;0.0001).

Conclusions: We further have confirmed with the 101-gene algorithm that the IM signature inversely associates with the M subtype as it has been observed with the 2188 gene algorithm (Lehmann et al., 2016). Moreover, the M signature is occasionally a confounder of other subtypes however still identifies those tumors negative for immune infiltrates. This raises important opportunities to understand the relationships between intrinsic tumor biology reflected in TNBC subtypes and their interaction with variable immune cell stroma which are the subject of ongoing analyses.

Citation Format: Grigoriadis A, Quist J, Mirza H, Cheang MC, Ring BZ, Hout DR, Bailey DB, Seitz RS, Tutt AN. Mesenchymal subtype negatively associates with the presence of immune infiltrates within a triple negative breast cancer classifier [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-07-03.

Signatures of mutational processes in human cancer

All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362 mutations from 7,042 cancers and extracted more than 20 distinct mutational signatures. Some are present in many cancer types, notably a signature attributed to the APOBEC family of cytidine deaminases, whereas others are confined to a single cancer class. Certain signatures are associated with age of the patient at cancer diagnosis, known mutagenic exposures or defects in DNA maintenance, but many are of cryptic origin. In addition to these genome-wide mutational signatures, hypermutation localized to small genomic regions, 'kataegis', is found in many cancer types. The results reveal the diversity of mutational processes underlying the development of cancer, with potential implications for understanding of cancer aetiology, prevention and therapy.

Signatures of mutational processes in human cancer

All cancers are caused by somatic mutations; however, understanding of the biological processes generating these mutations is limited. The catalogue of somatic mutations from a cancer genome bears the signatures of the mutational processes that have been operative. Here we analysed 4,938,362 mutations from 7,042 cancers and extracted more than 20 distinct mutational signatures. Some are present in many cancer types, notably a signature attributed to the APOBEC family of cytidine deaminases, whereas others are confined to a single cancer class. Certain signatures are associated with age of the patient at cancer diagnosis, known mutagenic exposures or defects in DNA maintenance, but many are of cryptic origin. In addition to these genome-wide mutational signatures, hypermutation localized to small genomic regions, 'kataegis', is found in many cancer types. The results reveal the diversity of mutational processes underlying the development of cancer, with potential implications for understanding of cancer aetiology, prevention and therapy.

BRCA1 dysfunction in sporadic basal-like breast cancer

Basal-like breast cancers form a distinct subtype of breast cancer characterized by the expression of markers expressed in normal basal/myoepithelial cells. Breast cancers arising in carriers of germline BRCA1 mutations are predominately of basal-like type, suggesting that BRCA1 dysfunction may play a role in the pathogenesis of sporadic basal-like cancers. We analysed 37 sporadic breast cancers expressing the basal marker cytokeratin 5/6, and age- and grade-matched controls, for downregulation of BRCA1. Although BRCA1 promoter methylation was no more common in basal-like cancers (basal 14% vs controls 11%, P=0.72), BRCA1 messenger RNA expression was twofold lower in basal-like breast cancers compared to matched controls (P=0.008). ID4, a negative regulator of BRCA1, was expressed at 9.1-fold higher levels in basal-like breast cancer (P<0.0001), suggesting a potential mechanism of BRCA1 downregulation. BRCA1 downregulation correlated with the presence of multiple basal markers, revealing heterogeneity in the basal-like phenotype. Finally, we found that 63% of metaplastic breast cancers, a rare type of basal-like cancers, had BRCA1 methylation, in comparison to 12% of controls (P<0.0001). The high prevalence of BRCA1 dysfunction identified in this study could be exploited in the development of novel approaches to targeted treatment of basal-like breast cancer.

Enteropathy associated T cell lymphoma presenting as an isolated CNS lymphoma three years after diagnosis of coeliac disease: T cell receptor polymerase chain reaction studies failed to show the original enteropathy to be a clonal disorder

A case of enteropathy associated T cell lymphoma is reported in a 45 year old woman, presenting with isolated disease in the CNS, three years after diagnosis of coeliac disease. Initial staging showed no evidence of gastrointestinal tract lymphoma. A presumptive diagnosis of T cell primary cerebral lymphoma was made and the patient was treated with combination chemotherapy and craniospinal radiotherapy. The patient relapsed, seven months after treatment, with small bowel lymphoma. The immunophenotype and T cell receptor polymerase chain reaction analysis confirmed the same tumour as in the CNS. Retrospective polymerase chain reaction analysis of intraepithelial lymphocytes in the duodenal biopsy sample, taken at the time of diagnosis of coeliac disease, failed to show evidence of a clonal T cell proliferation.