Florine A. Eggink

POLE Proofreading Mutations Elicit an Antitumor Immune Response in Endometrial Cancer

Purpose: Recent studies have shown that 7% to 12% of endometrial cancers are ultramutated due to somatic mutation in the proofreading exonuclease domain of the DNA replicase POLE. Interestingly, these tumors have an excellent prognosis. In view of the emerging data linking mutation burden, immune response, and clinical outcome in cancer, we investigated whether POLE-mutant endometrial cancers showed evidence of increased immunogenicity. Experimental Design: We examined immune infiltration and activation according to tumor POLE proofreading mutation in a molecularly defined endometrial cancer cohort including 47 POLE-mutant tumors. We sought to confirm our results by analysis of RNAseq data from the TCGA endometrial cancer series and used the same series to examine whether differences in immune infiltration could be explained by an enrichment of immunogenic neoepitopes in POLE-mutant endometrial cancers. Results: Compared with other endometrial cancers, POLE mutants displayed an enhanced cytotoxic T-cell response, evidenced by increased numbers of CD8+ tumor-infiltrating lymphocytes and CD8A expression, enrichment for a tumor-infiltrating T-cell gene signature, and strong upregulation of the T-cell cytotoxic differentiation and effector markers T-bet, Eomes, IFNG, PRF, and granzyme B. This was accompanied by upregulation of T-cell exhaustion markers, consistent with chronic antigen exposure. In silico analysis confirmed that POLE-mutant cancers are predicted to display more antigenic neoepitopes than other endometrial cancers, providing a potential explanation for our findings. Conclusions: Ultramutated POLE proofreading-mutant endometrial cancers are characterized by a robust intratumoral T-cell response, which correlates with, and may be caused by an enrichment of antigenic neopeptides. Our study provides a plausible mechanism for the excellent prognosis of these cancers. Clin Cancer Res; 21(14); 3347–55. ©2015 AACR.

Immunological profiling of molecularly classified high-risk endometrial cancers identifies POLE-mutant and microsatellite unstable carcinomas as candidates for checkpoint inhibition

ABSTRACT High-risk endometrial cancer (EC) is an aggressive disease for which new therapeutic options are needed. Aims of this study were to validate the enhanced immune response in highly mutated ECs and to explore immune profiles in other EC subgroups. We evaluated immune infiltration in 116 high-risk ECs from the TransPORTEC consortium, previously classified into four molecular subtypes: (i) ultramutated POLE exonuclease domain-mutant ECs (POLE-mutant); (ii) hypermutated microsatellite unstable (MSI); (iii) p53-mutant; and (iv) no specific molecular profile (NSMP). Within The Cancer Genome Atlas (TCGA) EC cohort, significantly higher numbers of predicted neoantigens were demonstrated in POLE-mutant and MSI tumors compared with NSMP and p53-mutants. This was reflected by enhanced immune expression and infiltration in POLE-mutant and MSI tumors in both the TCGA cohort (mRNA expression) and the TransPORTEC cohort (immunohistochemistry) with high infiltration of CD8+ (90% and 69%), PD-1+ (73% and 69%) and PD-L1+ immune cells (100% and 71%). Notably, a subset of p53-mutant and NSMP cancers was characterized by signs of an antitumor immune response (43% and 31% of tumors with high infiltration of CD8+ cells, respectively), despite a low number of predicted neoantigens. In conclusion, the presence of enhanced immune infiltration, particularly high numbers of PD-1 and PD-L1 positive cells, in highly mutated, neoantigen-rich POLE-mutant and MSI endometrial tumors suggests sensitivity to immune checkpoint inhibitors.

CD103+ intraepithelial T cells in high-grade serous ovarian cancer are phenotypically diverse TCRαβ+ CD8αβ+ T cells that can be targeted for cancer immunotherapy

CD103+ tumor-infiltrating lymphocytes (TIL) have been linked to specific epithelial infiltration and a prolonged survival in high-grade serous epithelial ovarian cancer (HGSC). However, whether these cells are induced as part of an ongoing anti-HGSC immune response or represent non-specifically expanded resident or mucosal lymphocytes remains largely unknown. In this study, we first confirmed that CD103+ TIL from HGSC were predominantly localized in the cancer epithelium and were strongly correlated with an improved prognosis. We further demonstrate that CD103+ TIL were almost exclusively CD3+ TCRαβ+ CD8αβ+ CD4- T cells, but heterogeneously expressed T cell memory and differentiation markers. Activation of peripheral T cells in the presence of HGSC was sufficient to trigger induction of CD103 in over 90% of all CD8+ cells in a T cell receptor (TCR)- and TGFβR1-dependent manner. Finally, CD103+ TIL isolated from primary HGSC showed signs of recent activation and dominantly co-expressed key immunotherapeutic targets PD-1 and CD27. Taken together, our data indicate CD103+ TIL in HGSC are formed as the result of an adaptive anti-tumor immune response that might be reactivated by (dual) checkpoint inhibition.

Improved outcomes due to changes in organization of care for patients with ovarian cancer in the Netherlands

OBJECTIVES Objectives of this study were to evaluate the effect of changes in patterns of care, for example centralization and treatment sequence, on surgical outcome and survival in patients with epithelial ovarian cancer (EOC). METHODS Patients diagnosed with FIGO stage IIB-IV EOC (2004-2013) were selected from the Netherlands Cancer Registry. Primary outcomes were surgical outcome (extent of macroscopic residual tumor after surgery) and overall survival. Changes in treatment sequence (primary debulking surgery and adjuvant chemotherapy (PDS+ACT) or neo-adjuvant chemotherapy and interval debulking surgery (NACT+IDS)), hospital type and annual hospital volume were also evaluated. RESULTS Patient and tumor characteristics of 7987 patients were retrieved. Most patients were diagnosed with stage III-IV EOC. The average annual case-load per hospital increased from 8 to 28. More patients received an optimal cytoreduction (tumor residue≤1cm) in 2013 (87%) compared to 2004 (55%, p<0.001). Complete cytoreduction (no macroscopic residual tumor), registered since 2010, increased from 42% to 52% (2010 and 2013, respectively, p<0.001). Optimal/complete cytoreduction was achieved in 85% in high volume (≥20 cytoreductive surgeries annually), 80% in medium (10-19 surgeries) and 71% in small hospitals (<10 surgeries, p<0.001). Within a selection of patients with advanced stage disease that underwent surgery the proportion of patients undergoing NACT+IDS increased from 28% (2004) to 71% (2013). Between 2004 and 2013 a 3% annual reduction in risk of death was observed (HR 0.97, p<0.001). CONCLUSION Changes in pattern of care for patients with EOC in the Netherlands have led to improvement in surgical outcome and survival.

The impact of centralization of services on treatment delay in ovarian cancer: A study on process quality

Objective Emphasis on improving healthcare quality has led to centralization of services for patients suspected of ovarian cancer. As centralization of services may induce treatment delays, we aimed to assess compliance with health system interval guidelines in patients suspected of ovarian cancer. Design Evaluation of health system intervals, comparison between direct and indirect referrals and between 2013 and 2014. Setting A managed clinical network (MCN) comprising 11 hospitals in the Netherlands. Participants Patients that were treated for ovarian cancer within the University Medical Center Groningen in 2013 and 2014. Intervention Introduction of an MCN to centralize services for patients suspected of ovarian cancer. Main Outcome Measure Compliance with national guidelines regarding health system intervals. Results Between 2013 and 2014 a clinically relevant improvement in compliance with guidelines was demonstrated. Within this period, median treatment intervals decreased from 34 to 29 days, and the percentage of patients in which treatment interval guidelines were met increased from 63.5 to 72.2%. New regulations and increased awareness of health system intervals inspired changes in local practice leading to improved compliance with guidelines. Compliance was highest in patients that were directly referred to our academic hospital. Conclusion Evaluation of health system intervals in patients suspected of ovarian cancer was feasible and may be applicable to other MCNs. Though compliance with guidelines improved within the study period, there is potential for improvement. To facilitate real-time evaluation of compliance with national guidelines establishing uniformity of electronic patient files in the MCN is deemed essential.

Compliance with adjuvant treatment guidelines in endometrial cancer : Room for improvement in high risk patients

OBJECTIVES Compliance of physicians with guidelines has emerged as an important indicator for quality of care. We evaluated compliance of physicians with adjuvant therapy guidelines for endometrial cancer patients in the Netherlands in a population-based cohort over a period of 10years. METHODS Data from all patients diagnosed with endometrial cancer between 2005 and 2014, without residual tumor after surgical treatment, were extracted from the Netherlands Cancer Registry (N=14,564). FIGO stage, grade, tumor type and age were used to stratify patients into risk groups. Possible changes in compliance over time and impact of compliance on survival were assessed. RESULTS Patients were stratified into low/low-intermediate (52%), high-intermediate (21%) and high (20%) risk groups. Overall compliance with adjuvant therapy guidelines was 85%. Compliance was highest in patients with low/low-intermediate risk (98%, no adjuvant therapy indicated). The lowest compliance was determined in patients with high risk (61%, external beam radiotherapy with/without chemotherapy indicated). Within this group compliance decreased from 64% in 2005-2009 to 57% in 2010-2014. In high risk patients with FIGO stage III serous disease compliance was 55% (chemotherapy with/without radiotherapy indicated) and increased from 41% in 2005-2009 to 66% in 2010-2014. CONCLUSION While compliance of physicians with adjuvant therapy guidelines is excellent in patients with low and low-intermediate risk, there is room for improvement in high risk endometrial cancer patients. Eagerly awaited results of ongoing randomized clinical trials may provide more definitive guidance regarding adjuvant therapy for high risk endometrial cancer patients.

TGF-β induced CXCL13 in CD8+ T cells is associated with tertiary lymphoid structures in cancer

Coordinated immune responses against human tumors are frequently characterized by tertiary lymphoid structures (TLS) which predict improved prognosis. The development of TLS is dependent on the chemokine CXCL13, reported to be secreted by dendritic cells and follicular helper T cells only. We report the unexpected finding that CXCL13 is also secreted by activated CD8+ T cells following stimulation by transforming growth factor beta (TGF-β). Using single cell RNA sequencing we found that expression of CXCL13 in CD8+ T cells was restricted to the intraepithelial CD103+ population. Accordingly, CD8+ T cells activated in the presence of TGF-β simultaneously upregulated CD103 and secreted CXCL13. CXCL13 expression was strongly correlated with neo-antigen burden and cytolytic gene signatures in bulk tumors. In line with this, TLS were abundant in neo-antigen-high, CD103+ T cell-enriched tumors. TGF-β thus appears to play a role in coordinating immune responses against human tumors through CD8-dependent CXCL13-associated formation of TLS.

Corrigendum to "Less-favourable prognosis for low-risk endometrial cancer patients with a discordant pre- versus post-operative risk stratification" [Eur J Cancer 78 (2017) 82-90]

The authors regret that reference 5 (Milam et al., 2011) in the original article was included in the reference list incorrectly, and it should not have been included. The authors apologise for any inconvenience caused.

Surgery for patients with newly diagnosed advanced ovarian cancer: which patient, when and extent?

Purpose of review Cytoreduction to no residual disease is the mainstay of primary treatment for advanced epithelial ovarian cancer (AdvEOC). This review addresses recent insights on optimal patient selection, timing, and extent of surgery, intended to optimize cytoreduction in patients with AdvEOC. Recent findings Clinical guidelines recommend primary cytoreductive surgery (PCS) for AdvEOC patients with a high likelihood of achieving complete cytoreduction with acceptable morbidity. In line with this, preoperative prediction markers such as cancer antigen-125, histologic and genomic factors, innovative imaging modalities, and the performance of a diagnostic laparoscopy have been suggested to improve clinical decision-making with regard to optimal timing of cytoreductive surgery. To determine whether these strategies should be incorporated into clinical practice validation in randomized clinical trials is essential. Summary The past decade has seen a paradigm shift in the number of AvdEOC patients that are being treated with upfront neoadjuvant chemotherapy instead of PCS. However, although neoadjuvant chemotherapy may reduce morbidity at the time of interval cytoreductive surgery, no favorable impact on survival has been demonstrated and it may induce resistance to chemotherapy. Therefore, optimizing patient selection for PCS is crucial. Furthermore, surgical innovations in patients diagnosed with AvdEOC should focus on improving survival outcomes.

Abstract 1687: Systemic immunological changes during first line chemotherapy in patients with high-grade serous ovarian cancer

Ovarian cancer remains the most lethal gynecological malignancy and new therapeutic strategies are urgently needed. High-grade serous ovarian cancer (HGSC), in particular, is associated with a five-year survival of only 40%. A promising new approach for treating HGSC is immunotherapy, which has resulted in complete and durable responses, albeit in a minority of patients. One potential approach for improving these response rates is by combining chemo- and immunotherapy. Indeed, carboplatin/taxol chemotherapy was shown to augment immune responses in cervical cancer patients by depleting circulating myeloid suppressor cells. As patients with HGSC are treated in first line with similar carboplatin/taxol chemotherapy, we explored the effects of chemotherapy on systemic immunity in HGSC patients. Within this prospective observational study, 75 patients with suspected ovarian cancer were included. Blood was collected at three different time points during first line chemotherapy treatment, namely: prior to chemotherapy, between the third and fourth cycle of chemotherapy and 4-6 weeks after the sixth cycle of chemotherapy. All patients received 6 cycles of carboplatin/taxol chemotherapy and cytoreductive surgery (either as primary debulking, or after 3 cycles of neo-adjuvant chemotherapy). Peripheral blood mononuclear cells were isolated and analyzed for a total of 36 immune markers using 9 flow cytometry panels, in total analyzing 49 immune cell subsets. Results were compared to an age-matched cohort consisting of women surgically treated for a benign disease, and a cohort of healthy young volunteers. 75 patients have been included so far from which 22 were diagnosed with benign disease, 3 were diagnosed with another malignancy, and 50 were diagnosed with OC. Of the 50 OC patients, 18 were diagnosed with HGSC and from 9 HGSC patients, multiple time points were available for analysis of chemotherapy-dependent changes in the immune cell subsets. All patients developed leukopenia as a result of chemotherapeutic treatment. Age-related changes in lymphocyte and myeloid cell subsets were observed in all HGSC patients and patients with benign disease. Chemotherapy-dependent depletion of myeloid cells was observed in a subset of patients. Depletion of myeloid subsets was equally distributed among monocytes, macrophages and dendritic cells. No HGSC- or chemotherapy-dependent changes in T cell subsets or migration and activation markers were observed. Taken together, we observed no major systemic changes in immune cell subsets during carboplatin/taxol chemotherapy treatment, suggesting that combined chemo-immunotherapeutic strategies could be feasible during first line treatment of HGSC. Citation Format: Fenne L. Komdeur, Florine A. Eggink, Ninke Leffers, Hagma H. Workel, Kim L. Brunekreeft, Annechien Plat, Marco de Bruyn, Hans W. Nijman. Systemic immunological changes during first line chemotherapy in patients with high-grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1687. doi:10.1158/1538-7445.AM2017-1687