PIK3R1W624R Is an Actionable Mutation in High Grade Serous Ovarian Carcinoma

Identifying cancer drivers and actionable mutations is critical for precision oncology. In epithelial ovarian cancer (EOC) the majority of mutations lack biological or clinical validation. We fully characterized 43 lines of Patient-Derived Xenografts (PDXs) and performed copy number analysis and whole exome sequencing of 12 lines derived from naïve, high grade EOCs. Pyrosequencing allowed quantifying mutations in the source tumours. Drug response was assayed on PDX Derived Tumour Cells (PDTCs) and in vivo on PDXs. We identified a PIK3R1W624R variant in PDXs from a high grade serous EOC. Allele frequencies of PIK3R1W624R in all the passaged PDXs and in samples of the source tumour suggested that it was truncal and thus possibly a driver mutation. After inconclusive results in silico analyses, PDTCs and PDXs allowed the showing actionability of PIK3R1W624R and addiction of PIK3R1W624R carrying cells to inhibitors of the PI3K/AKT/mTOR pathway. It is noteworthy that PIK3R1 encodes the p85α regulatory subunit of PI3K, that is very rarely mutated in EOC. The PIK3R1W624R mutation is located in the cSH2 domain of the p85α that has never been involved in oncogenesis. These data show that patient-derived models are irreplaceable in their role of unveiling unpredicted driver and actionable variants in advanced ovarian cancer.

Transcriptional Characterization of Stage I Epithelial Ovarian Cancer: A Multicentric Study

Stage I epithelial ovarian cancer (EOC) represents about 10% of all EOCs. It is characterized by a complex histopathological and molecular heterogeneity, and it is composed of five main histological subtypes (mucinous, endometrioid, clear cell and high, and low grade serous), which have peculiar genetic, molecular, and clinical characteristics. As it occurs less frequently than advanced-stage EOC, its molecular features have not been thoroughly investigated. In this study, using in silico approaches and gene expression data, on a multicentric cohort composed of 208 snap-frozen tumor biopsies, we explored the subtype-specific molecular alterations that regulate tumor aggressiveness in stage I EOC. We found that single genes rather than pathways are responsible for histotype specificities and that a cAMP-PKA-CREB1 signaling axis seems to play a central role in histotype differentiation. Moreover, our results indicate that immune response seems to be, at least in part, involved in histotype differences, as a higher immune-reactive behavior of serous and mucinous samples was observed with respect to other histotypes.

Abstract GMM-023: PATIENT DERIVED XENOGRAFTS (PDXS) AND PDX DERIVED TUMOR CELLS (PDTC) ALLOW THE IDENTIFICATION OF ACTIONABLE CANCER GENES AND TREATMENT OPTIONS FOR PLATINUM REFRACTORY/RESISTANT OVARIAN CARCINOMAS

Patients with advanced ovarian cancers have experienced little improvement in overall survival with standard treatments even after the incorporation of anti-angiogenic therapies. Besides anti-PARP inhibitors, matching individual critical genomic alterations with the best available drugs has not advanced as in other cancers, likely because a handful of cancer-related genes are mutated at high frequency, while many more are found mutated at much lower frequencies. This so called “mutation tail” is not only long but also mostly unexplored.

We used Patient Derived Xenografts (PDXs) to identify actionable cancer genes and PDX Derived Tumor Cells (PDTCs) to accelerate the discovery of treatment options. We envisioned that the alleged weakness of PDX models, i.e. lack of human stromal and immune cells, might be instrumental to identify mutations in cancer and to test approved or experimental targeted drugs as monotherapy or in different combinations to link biomarkers to treatments.

Forty-nine PDX lines from metastatic epithelial ovarian carcinomas have been propagated and fully characterized as far as histology, immunohistochemistry of epithelial and high-grade serous-specific markers and presence of TP53 and BRCA1/2 mutations.

Copy number variations (CNV) analysis and Whole Exome Sequencing (WES) were carried out PDX lines derived from naïve metastatic high-grade epithelial ovarian carcinomas, which came out to be refractory/resistant to platinum drugs. We studied non-synonymous mutations with allele frequencies ≥0.1. Only mutations in cancer genes listed in databases were further analyzed. SNPdb allowed ruling out polymorphisms. SIFT and PROVEAN softwares predicted deleterious or damaging effects onto the protein sequences. DGIdb helped selecting actionable genes.

We identified in one PDX line, a possibly loss-of-function mutation of the PIK3R1 gene (encoding the p85alpha regulatory subunit of PI3K) had an allele frequency=0.9 in early and late passages. Moreover, in two micro-dissected FFPE samples of the source tumor this mutation had an allele frequency nearly identical to that of the mutated TP53. Hence, PIK3R1W624R could be a trunk mutation in the PDX line and possibly in the human counterpart.

Treatment options were assayed ex-vivo, on short-term cultures of PDTCs of the PIK3R1W624R PDX line. Buparlisib, a pan-class I PI3K inhibitor, showed the ability to block proliferation of PDTCs and the growth in vivo of PDXs in regression preclinical trial. These data proofed-the-concept that a PDX-based pipeline is able to unveil actionable pathways for the treatment of advanced/metastatic ovarian cancer.

Citation Format: Martina Olivero, Jessica Erriquez, Maddalena Arigoni, Sonia Capellero, Concetta D'Ambrosio, Gloria Mittica, Fulvio Borella, Dionyssios Katsaros, Silvana Privitera, Enrico Berrino, Tiziana Venesio, Giorgio Valabrega, Raffaele Calogero and Maria Flavia Di Renzo. PATIENT DERIVED XENOGRAFTS (PDXS) AND PDX DERIVED TUMOR CELLS (PDTC) ALLOW THE IDENTIFICATION OF ACTIONABLE CANCER GENES AND TREATMENT OPTIONS FOR PLATINUM REFRACTORY/RESISTANT OVARIAN CARCINOMAS [abstract]. In: Proceedings of the 12th Biennial Ovarian Cancer Research Symposium; Sep 13-15, 2018; Seattle, WA. Philadelphia (PA): AACR; Clin Cancer Res 2019;25(22 Suppl):Abstract nr GMM-023.

Adjuvant chemoradiotherapy versus radiotherapy alone in women with high-risk endometrial cancer (PORTEC-3): patterns of recurrence and post-hoc survival analysis of a randomised phase 3 trial

BACKGROUND

The PORTEC-3 trial investigated the benefit of combined adjuvant chemotherapy and radiotherapy versus pelvic radiotherapy alone for women with high-risk endometrial cancer. We updated the analysis to investigate patterns of recurrence and did a post-hoc survival analysis.

METHODS

In the multicentre randomised phase 3 PORTEC-3 trial, women with high-risk endometrial cancer were eligible if they had International Federation of Gynaecology and Obstetrics (FIGO) 2009 stage I, endometrioid grade 3 cancer with deep myometrial invasion or lymphovascular space invasion, or both; stage II or III disease; or stage I-III disease with serous or clear cell histology; were aged 18 years and older; and had a WHO performance status of 0-2. Participants were randomly assigned (1:1) to receive radiotherapy alone (48·6 Gy in 1·8 Gy fractions given on 5 days per week) or chemoradiotherapy (two cycles of cisplatin 50 mg/m² given intravenously during radiotherapy, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m² given intravenously), by use of a biased coin minimisation procedure with stratification for participating centre, lymphadenectomy, stage, and histological type. The co-primary endpoints were overall survival and failure-free survival. Secondary endpoints of vaginal, pelvic, and distant recurrence were analysed according to the first site of recurrence. Survival endpoints were analysed by intention-to-treat, and adjusted for stratification factors. Competing risk methods were used for failure-free survival and recurrence. We did a post-hoc analysis to analyse patterns of recurrence with 1 additional year of follow-up. The study was closed on Dec 20, 2013; follow-up is ongoing. This study is registered with ISRCTN, number ISRCTN14387080, and ClinicalTrials.gov, number NCT00411138.

FINDINGS

Between Nov 23, 2006, and Dec 20, 2013, 686 women were enrolled, of whom 660 were eligible and evaluable (330 in the chemoradiotherapy group, and 330 in the radiotherapy-alone group). At a median follow-up of 72·6 months (IQR 59·9-85·6), 5-year overall survival was 81·4% (95% CI 77·2-85·8) with chemoradiotherapy versus 76·1% (71·6-80·9) with radiotherapy alone (adjusted hazard ratio [HR] 0·70 [95% CI 0·51-0·97], p=0·034), and 5-year failure-free survival was 76·5% (95% CI 71·5-80·7) versus 69·1% (63·8-73·8; HR 0·70 [0·52-0·94], p=0·016). Distant metastases were the first site of recurrence in most patients with a relapse, occurring in 78 of 330 women (5-year probability 21·4%; 95% CI 17·3-26·3) in the chemoradiotherapy group versus 98 of 330 (5-year probability 29·1%; 24·4-34·3) in the radiotherapy-alone group (HR 0·74 [95% CI 0·55-0·99]; p=0·047). Isolated vaginal recurrence was the first site of recurrence in one patient (0·3%; 95% CI 0·0-2·1) in both groups (HR 0·99 [95% CI 0·06-15·90]; p=0·99), and isolated pelvic recurrence was the first site of recurrence in three women (0·9% [95% CI 0·3-2·8]) in the chemoradiotherapy group versus four (0·9% [95% CI 0·3-2·8]) in the radiotherapy-alone group (HR 0·75 [95% CI 0·17-3·33]; p=0·71). At 5 years, only one grade 4 adverse event (ileus or obstruction) was reported (in the chemoradiotherapy group). At 5 years, reported grade 3 adverse events did not differ significantly between the two groups, occurring in 16 (8%) of 201 women in the chemoradiotherapy group versus ten (5%) of 187 in the radiotherapy-alone group (p=0·24). The most common grade 3 adverse event was hypertension (in four [2%] women in both groups). At 5 years, grade 2 or worse adverse events were reported in 76 (38%) of 201 women in the chemoradiotherapy group versus 43 (23%) of 187 in the radiotherapy-alone group (p=0·002). Sensory neuropathy persisted more often after chemoradiotherapy than after radiotherapy alone, with 5-year rates of grade 2 or worse neuropathy of 6% (13 of 201 women) versus 0% (0 of 187). No treatment-related deaths were reported.

INTERPRETATION

This updated analysis shows significantly improved overall survival and failure-free survival with chemoradiotherapy versus radiotherapy alone. This treatment schedule should be discussed and recommended, especially for women with stage III or serous cancers, or both, as part of shared decision making between doctors and patients. Follow-up is ongoing to evaluate long-term survival.

FUNDING

Dutch Cancer Society, Cancer Research UK, National Health and Medical Research Council, Project Grant, Cancer Australia Grant, Italian Medicines Agency, and the Canadian Cancer Society Research Institute.

Clinico-pathological features of gynecological myopericytoma: a challenging diagnosis in an exceptional location

Myopericytomas (MPC) are rare mesenchymal tumors, originating from the perivascular myoid cells. They predominantly occur in the skin and superficial soft tissues of the extremities, while visceral involvement is rare. Histological features and clinical course are usually benign. To the best of our knowledge, MPC is still an uncharacterized tumor entity of the female internal genital tract. We describe three MPC cases involving the female internal genital tract: (1) a uterine wall MPC arising in a 49-year-old woman with progressive pelvic/abdominal pain; (2) a cervix MPC of a 49-year-old woman who presented with metrorrhagia, and (3) a MPC presenting as a simple ovarian cyst in a 26-year-old woman with pain located in the left iliac fossa. All patients were surgically treated, and recurrence occurred in two cases. The histological and immunohistochemical findings, supporting the diagnosis of MPC, are presented; in particular, one case showed characteristics pointing towards an uncertain biological behavior/low-grade malignancy. A literature search was conducted to identify previous reports of gynecological MPC and for possible alternative diagnoses. Leiomyoma, epithelioid leiomyoma, angioleiomyoma, perivascular epithelioid cell tumor, solitary fibrous tumor, and low-grade endometrial stromal sarcoma should be considered in the differential diagnosis. Awareness of possible occurrence of this rare neoplasm in the female genital tract is important to reach a correct diagnosis in the spectrum of mesenchymal tumors. Considering the risk of recurrence, we recommend careful evaluation of surgical margins and complete surgical removal whenever possible.

Abstract 3545: High expression of miR-30a is associated with favorable breast cancer survival

Introduction: MicroRNAs (miRNAs) are single-stranded, small non-coding RNAs, consisting of about 20 nucleotides and studies have shown that miRNAs may play important roles in the development and progression of cancer. Members of the miR-30 family, including miR-30a, are reported to play different roles as oncogenes or tumor suppressor genes depending on the type of cancer in several studies. We studied miR-30a expression in breast cancer in relation to disease features and patient survival.

Methods: We measured miR-30a expression in tumor samples of 509 breast cancer patients by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). Using the study-specific tertile distribution as cut-off, miR-30a expression data were grouped into low, medium, and high three categories. Hazards ratios (HRs) and 95% confidence intervals (CIs) were calculated to assess the association between miR-30a expression and breast cancer survival using the Cox proportional hazards regression model, and the analysis was adjusted for age at surgery, tumor grade, disease stage, and hormone receptor status. Overall survival (OS) was defined as the time interval from the date of surgery to the date of death or last follow-up. Disease-free survival (DFS) was the time interval from surgery to recurrence or last follow-up. We also retrieved breast cancer provisional data in The Cancer Genome Atlas (TCGA) using the web-based tool cBioPortal (http://www.cbioportal.org/index.do) and analyzed the association between miR-30a and breast cancer survival.

Results: Patients with estrogen receptor (ER)-positive tumors had higher expression of miR-30a compared to those with ER-negative tumors (p = 0.0080). Patients with progesterone receptor (PR)-positive tumors also had higher miR-30a expression than those with PR-negative tumors (p = 0.0038). Survival analysis showed that patients with high expression of miR-30a had 58% reduction in risk of relapse (HR = 0.42, 95% CI = 0.21-0.83, p = 0.013) compared to those with low expression. This association remained significant (HR = 0.43, 95% CI = 0.21-0.89, p = 0.023) after adjustment for age at surgery, disease stage, tumor grade, and hormone receptor status. A significant association between miR-30a and overall survival was also observed in the TCGA data (HR = 0.60, 95% CI = 0.41-0.88, p = 0.0088).

Conclusions: Our results suggest that high expression of miR-30a may reduce the risk of breast cancer relapse and miR-30a may act as a tumor suppressor in breast cancer.

Citation Format: Yuki Obata, Dionyssios Katsaros, Nicoletta Biglia, Yi Shen, Yuanyuan Fu, Zhanwei Wang, Herbert Yu. High expression of miR-30a is associated with favorable breast cancer survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3545.

Low expression of WWC1, a tumor suppressor gene, is associated with aggressive breast cancer and poor survival outcome

The WW and C2 domain containing 1 (WWC1) gene encodes a protein named WWC1 (or KIBRA), which is involved in the Hippo signaling pathway. WWC1 is often lost in triple-negative breast cancer and has been shown to suppress tumor metastasis. In this study, 470 breast cancer patients were recruited and WWC1 expression in the tumor samples was measured with quantitative reverse transcriptase PCR. Associations of WWC1 expression with breast cancer survival were analyzed using the Cox proportional hazards regression model and Kaplan-Meier survival analysis. The relationship between WWC1 expression and methylation was evaluated in a dataset from The Cancer Genome Atlas. Using our microarray data on gene expression and the Ingenuity Pathway Analysis, we predicted the WWC1-associated signaling pathways in breast cancer. Our results showed that low expression of WWC1 was significantly associated with advanced-stage diseases, high-grade tumors, and estrogen receptor- or progesterone receptor-negative status. Compared to those with high expression, patients with low WWC1 had higher risk of breast cancer relapse [hazard ratio (HR) = 2.06, 95% confidence interval (CI): 1.26-3.37] and higher risk of death (HR = 2.76, 95% CI: 1.51-5.03). The association with relapse-free survival remained significant after adjustment for disease stage, tumor grade, and hormone receptor status and was replicated in a public dataset. Analysis of high-throughput gene expression data indicated that WWC1 was involved in the Hippo signaling pathway. Online data also suggested that DNA methylation was inversely associated with WWC1 expression. The study confirmed that low WWC1 expression was associated with aggressive breast cancer and poor survival outcomes.

Results from neoadjuvant chemotherapy followed by surgery compared to chemoradiation for stage Ib2-IIb cervical cancer, EORTC 55994

5503

Background: Conflicting evidence on the value of neoadjuvant chemotherapy followed by surgery compared to concomitant chemoradiation in Stage IB2-IIB cervical carcinoma led to this multinational multicenter trial. As the trial is approaching completion of its follow-up, preliminary results are presented. Methods: Between May 2002 and June 2014 a total of 620 patients with FIGO stage Ib2-IIb were randomized between neoadjuvant chemotherapy followed by surgery (NACTS, arm 1, N=311) with standard concomitant chemoradiotherapy (CCRT, arm 2, N=309) . In arm 1, radical hysterectomy was required within 6 weeks after completion of cisplatin-based chemotherapy with a cumulative minimum of 225mg/m2, in arm 2, radiation consisted of 45-50 Gy plus boost concurrent with weekly cisplatin chemotherapy (40 mg/m2 per week). Primary endpoint was 5-yrs overall survival (OS). Results: Median follow-up time was 8.2 years ( 95% CI = 7.8 yrs – 8.6 yrs)) and similar between both arms. A total of 191 deaths (31%) occurred. Age, stage and histological cell type were balanced in both arms. Protocol treatment was completed in 459 (74%) patients (71% for NACTS; 82% for CCRT). In arm 1 238 (76%) patients underwent surgery. Main reasons for not having surgery as per protocol, were toxicity (25/74, 34%), progressive disease (18/74, 24%) and insufficient response to NACT (12/74, 16%). Additional radiotherapy was given to 113 patients (36.3%) in arm 1; additional surgery performed in 9 patients (2.9%) in arm 2. Short term severe adverse events (≥G3) occurred more frequently in arm 1 than in arm 2 (35% vs 21%, p < 0.001). The 5 year OS was 72% in arm 1 and 76% in arm 2 (not statistically significant, difference = 4.0% (95%CI: -4% - 12%); HR 0.87, 95%CI: 0.65-0.15, p=0.332). Conclusions: These preliminary results revealed no difference in 5-year OS between NACTS and CCRT, indicating that quality of life and long term toxicity are important to decide optimal treatment. The final results will be available by April 2019, including long-term toxicity and treatment effect across prognostic factors. Clinical trial information: NCT00039338.

Clinical consequences of upfront pathology review in the randomised PORTEC-3 trial for high-risk endometrial cancer

Background

In the PORTEC-3 trial, women with high-risk endometrial cancer (HR-EC) were randomised to receive pelvic radiotherapy (RT) with or without concurrent and adjuvant chemotherapy (two cycles of cisplatin 50 mg/m² in weeks 1 and 4 of RT, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m²). Pathology review was required before patient enrolment. The aim of this analysis was to evaluate the role of central pathology review before randomisation.

Patients and methods

A total of 1295 cases underwent pathology review to confirm HR-EC in the Netherlands (n = 395) and the UK (n = 900), and for 1226/1295 (95%) matching review and original reports were available. In total, 329 of these patients were enrolled in the PORTEC-3 trial: 145 in the Netherlands and 184 in the UK, comprising 48% of the total PORTEC-3 cohort of 686 participants. Areas of discrepancies were evaluated, and inter-observer agreement between original and review opinion was evaluated by calculating the kappa value (κ).

Results

In the 1226 pathology reviews, 6356 selected items were evaluable for both original and review pathology. In 43% of cases at least one pathology item changed after review. For 102 patients (8%), this discrepancy led to ineligibility for the PORTEC-3 trial, most frequently due to differences in the assessment of histological type (34%), endocervical stromal involvement (27%) and histological grade (19%). Lowest inter-observer agreement was found for histological type (κ = 0.72), lymph-vascular space invasion (κ = 0.72) and histological grade (κ = 0.70).

Conclusion

Central pathology review by expert gynaeco-pathologists changed histological type, grade or other items in 43% of women with HR-EC, leading to ineligibility for the PORTEC-3 trial in 8%. Upfront pathology review is essential to ensure enrolment of the target trial-population, and to avoid over- or undertreatment, especially when treatment modalities with substantial toxicity are involved.

This study is registered with ISRCTN (ISRCTN14387080, www.controlled-trials.com) and with ClinicalTrials.gov (NCT00411138).

ERα upregulates the expression of long non-coding RNA LINC00472 which suppresses the phosphorylation of NF-κB in breast cancer

PURPOSE

Low expression of long intergenic non-coding RNA LINC00472 in breast cancer is associated with aggressive tumors and unfavorable disease outcomes in multiple clinical datasets, but the reasons for these associations were unknown.

METHODS

To study the mechanisms underlying the lncRNA's connection to breast cancer, we investigated the molecular targets and regulation of LINC00472 in breast cancer cells, and analyzed relevant molecular features in relation to patient survival. Gene expression profiles of breast cancer cells overexpressing LINC00472 were analyzed for its regulatory pathways and downstream targets. Effects of LINC00472 overexpression on cell behaviors were evaluated in vitro and in vivo. Meta-analysis was performed using online datasets and our own study.

RESULTS

Analysis of LINC00472 transcriptome revealed ERα upregulation of LINC00472 expression, and an ERα-binding site in the LINC00472 promoter was identified. Evaluation of LINC00472 overexpression also indicated a possible link between LINC00472 and NF-κB. Cell experiments confirmed that LINC00472 suppressed the phosphorylation of p65 and IκBα through binding to IKKβ, inhibiting its phosphorylation. High LINC00472 expression inhibited tumor growth both in vitro and in vivo and suppressed aggressive tumor cell behaviors in vitro. Suppressing LINC00472 expression in ER-positive tumor cells increased cell aggressive behaviors. Tamoxifen treatment of ER-positive cells inhibited ERα and LINC00472 expression and increased p65 and IκBα phosphorylation. Meta-analysis showed that LINC00472 expression were higher in ER-positive than ER-negative tumors and that high expression was associated with better disease outcomes in ER-positive patients.

CONCLUSIONS

The study demonstrates that ERα upregulates LINC00472 which suppresses the phosphorylation of NF-κB, and suggests that endocrine treatment may lower LINC00472 and increase NF-κB activities, leading to tumor progression and disease recurrence.

Abstract 3102: Identification of actionable cancer genes and treatment options for metastatic ovarian carcinomas using patient-derived xenografts and PDX-derived tumor cells

Patients with advanced ovarian cancers have experienced little improvement in overall survival with standard treatments even after the incorporation of anti-angiogenic therapies. Besides anti-PARP inhibitors, matching individual critical genomic alterations with the best available drugs has not advanced as in other cancers, likely because a handful of cancer-related genes are mutated at high frequency, while many more are found mutated at much lower frequencies. This so called “mutation tail” is not only long but also mostly unexplored.

We used Patient Derived Xenografts (PDXs) to identify actionable cancer genes and PDX Derived Tumor Cells (PDTCs) to accelerate the discovery of treatment options. We envisioned that the alleged weakness of PDX models, i.e. lack of human stromal and immune cells, might be instrumental to identify mutations in cancer and to test approved or experimental targeted drugs as monotherapy or in different combinations to link biomarkers to treatments.

Fourty-nine PDX lines from metastatic epithelial ovarian carcinomas have been propagated and fully characterized as far as histology, immunohistochemistry of epithelial and high-grade serous-specific markers and presence of TP53 and BRCA1/2 mutations.

Copy number variations (CNV) analysis and Whole Exome Sequencing (WES) were carried out of 12 PDX lines derived from naïve metastatic high-grade serous epithelial ovarian carcinomas. We studied non-synonymous mutations with allele frequencies ≥0.1. Only mutations in cancer genes listed in databases were further analyzed. SNPdb allowed ruling out polymorphisms. SIFT and PROVEAN softwares predicted deleterious or damaging effects onto the protein sequences. DGIdb helped selecting actionable genes.

We identified mutations in 1-4 cancer genes in 8/12 PDX lines. In one PDX line, a possibly loss-of-function mutation of the PIK3R1 gene (encoding the p85alpha regulatory subunit of PI3K) had an allele frequency=0.9 in early and late passages. Moreover, in two micro-dissected FFPE samples of the source tumor this mutation had an allele frequency nearly identical to that of the mutated TP53. Hence, PIK3R1W624R could be a trunk mutation in the PDX line and possibly in the human counterpart.

Treatment options were assayed ex-vivo, on short-term cultures of PDTCs of the PIK3R1W624R PDX line. Buparlisib, a pan-class I PI3K inhibitor, showed the ability to block proliferation of PDTCs and the growth in vivo of PDXs in regression preclinical trial. These data proofed-the-concept that a PDX-based pipeline is able to unveil actionable pathways for the treatment of advanced/metastatic ovarian cancer.

Citation Format: Martina Olivero, Jessica Erriquez, Maddalena Arigoni, Sonia Capellero, Concetta D'Ambrosio, Gloria Mittica, Fulvio Borella, Dionyssios Katsaros, Silvana Privitera, Enrico Berrino, Tiziana Venesio, Giorgio Valabrega, Raffaele Calogero, Maria Flavia Di Renzo. Identification of actionable cancer genes and treatment options for metastatic ovarian carcinomas using patient-derived xenografts and PDX-derived tumor cells [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 3102.

A predictive score for optimal cytoreduction at interval debulking surgery in epithelial ovarian cancer: a two- centers experience

Background

Optimal cytoreduction (macroscopic Residual Tumor, RT = 0) is the best survival predictor factor in epithelial ovarian cancer (EOC). It doesn’t exist a consolidated criteria to predict optimal surgical resection at interval debulking surgery (IDS). The aim of this study is to develop a predictive model of complete cytoreduction at IDS.

Methods

We, retrospectively, analyzed 93 out of 432 patients, with advanced EOC, underwent neoadjuvant chemotherapy (NACT) and IDS from January 2010 to December 2016 in two referral cancer centers. The correlation between clinical-pathological variables and residual disease at IDS has been investigated with univariate and multivariate analysis. A predictive score of cytoreduction (PSC) has been created by combining all significant variables. The performance of each single variable and PSC has been reported and the correlation of all significant variables with progression free survival (PFS) has been assessed.

Results

At IDS, 65 patients (69,8%) had complete cytoreduction with no residual disease (R = 0). Three criteria independently predicted R > 0: age ≥ 60 years (p = 0.014), CA-125 before NACT > 550 UI/dl (p = 0.044), and Peritoneal Cancer Index (PCI) > 16 (p < 0.001). A PSC ≥ 3 has been associated with a better accuracy (85,8%), limiting the number of incomplete surgeries to 16,5%. Moreover, a PCI > 16, a PSC ≥ 3 and the presence of R > 0 after IDS were all significantly associated with shorter PFS (p < 0.001, p < 0.001 and p = 0.004 respectively).

Conclusions

Our PSC predicts, in a large number of patients, complete cytoreduction at IDS, limiting the rate of futile extensive surgeries in case of presence of residual tumor (R > 0). The PSC should be prospectively validated in a larger series of EOC patients undergoing NACT-IDS.

High expression of long non-coding RNA MALAT1 in breast cancer is associated with poor relapse-free survival

PURPOSE

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been identified as a prognostic marker for the metastasis of early-stage non-small cell lung cancer (NSCLCs). We studied MALAT1 expression in breast cancer in relation to disease features and patient survival.

METHODS

Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) was used to measure MALAT1 expression in tumor samples of 509 breast cancer patients. Hazards ratios (HRs) and 95% confidence intervals (CIs) were calculated to assess the association between MALAT1 expression and breast cancer survival using the Cox proportional hazards regression model, and the analysis was adjusted for age at surgery, tumor grade, disease stage, and hormone receptor status. Meta-analysis of multiple microarray datasets from online databases and our own study was performed to evaluate the association of MALAT1 with breast cancer survival.

RESULTS

Patients with low-grade or ER-positive tumors had higher expression of MALAT1 compared to those with high-grade (p = 0.013) or ER-negative (p = 0.0002) tumors. Patients with PR-positive tumors also had higher MALAT1 expression than those with PR-negative tumors (p < 0.0001). In patients with positive hormone receptors or low tumor grade, tumors with high MALAT1 expression were more likely to recur. Survival analysis showed that patients with high expression of MALAT1 had a twofold increase in risk of relapse (p = 0.0083) compared to those with low expression. This association remained significant after adjustment for age at surgery, disease stage, tumor grade, and hormone receptor status. Meta-analysis showed that high MALAT1 expression was associated with poor relapse-free survival in patients with hormone receptor-positive tumors (HR 1.44, 95% CI 1.08-1.92).

CONCLUSIONS

High expression of lncRNA MALAT1 is associated with breast cancer relapse and may play a role in tumor progression.

Xenopatients show the need for precision medicine approach to chemotherapy in ovarian cancer

Platinum-based chemotherapy is the recommended first-line treatment for high-grade serous (HGS) epithelial ovarian cancer (EOC). However, most patients relapse because of platinum refractory/resistant disease. We aimed at assessing whether other drugs, commonly used to treat relapsed HGS-EOC and poorly active in this clinical setting, might be more effective against chemotherapy-naïve cancers. We collected couples of HGS-EOC samples from the same patients before and after neo-adjuvant platinum-based chemotherapy. Samples were propagated as Patient Derived Xenografts (PDXs) in immunocompromised mice ("xenopatients"). Xenopatients were treated in parallel with carboplatin, gemcitabine, pegylated liposomal doxorubicin (PLD) and trabectedin. PDXs derived from a naïve HSG-EOC showed responsiveness to carboplatin, trabectedin and gemcitabine. The PDXs propagated from a tumor mass of the same patient, grown after carboplatin therapy, did no longer respond to trabectedin and gemcitabine and showed heterogeneous response to carboplatin. In line, the patient experienced clinically platinum-sensitivity first and then discordant responses of different tumor sites to platinum re-challenge. Loss of PDX responsiveness to drugs was associated with 4-fold increase of NR2F2 gene expression. PDXs from another naïve tumor showed complete response to PLD, which was lost in the PDXs derived from a mass grown in the same patient after platinum-based chemotherapy. This patient showed platinum refractoriness and responded poorly to PLD as second-line treatment. PDX response to PLD was associated with high expression of TOP2A protein. PDXs demonstrated that chemotherapy-naïve HGS-EOC might display susceptibility to agents not used commonly as first line treatment. Data suggest the importance of personalizing also chemotherapy.

Abstract P5-07-03: Withdrawn

This abstract was withdrawn by the authors.

Variation in gynecological oncology follow-up practice: Attributable to cancer centers or to patient characteristics? A Piedmont Regional Oncology Network Study

Aims and background

Although guidelines recommend minimalist follow-up, there is wide variability in gynecological oncology practice. The aims of this study were to describe between-center differences in the follow-up of endometrial, ovarian, and uterine cervical cancer; to identify the determinants of test prescription; to estimate the related costs; and to assess the weight of center habits and patient characteristics as sources of unexplained variability.

Methods and study design

The medical records of patients treated between August 2004 and July 2005 for gynecological malignancies and followed up for the detection of recurrent disease were retrospectively collected from 29 centers of the Piedmont Oncology Network. Multivariate multilevel analyses were performed to study the determinants of test prescription and costs.

Results

Analyses were performed on 351 patients (median follow-up: 578 days). The unexplained variability in computed tomography prescriptions (26%), ultrasound prescriptions (17%), and total cost of follow-up (15%) can be attributed to center habits, independenty of the clinical characteristics of the patients.

Conclusions

Much of the unexplained variability in the follow-up for gynecological malignancies is attributable to different habits of centers belonging to a cancer network. These results prompted us to design a multicenter randomized controlled trial to compare minimalist versus intensive follow-up programs in endometrial cancer.

High PTPN13 expression in high grade serous ovarian carcinoma is associated with a better patient outcome

Background

Chromosome 4q loss of heterozygosity (LOH) is frequently observed in high-grade serous ovarian carcinoma (HGSOC). However, this LOH has not been clearly associated with the inactivation of any tumor suppressor gene(s). As the tumor suppressor gene PTPN13 is located on chromosome 4q21, we investigated its expression in HGSOC.

Methods

PTPN13 protein expression was investigated by immunohistochemistry (IHC) in normal ovary epithelium and in 30 HGSOC samples, whereas PTPN13 mRNA expression was quantified by RT-PCR in another independent cohort of 28 HGSOC samples. Patients in both cohorts were followed for more than 8.5 years.

Results

PTPN13 protein expression was lower in one third of HGSOC samples compared with normal ovary epithelium. In both cohorts, high PTPN13 expression level (mRNA or protein) in the tumor was associated with favorable outcome and significantly longer survival (HR=0.27; p=0.0087 and HR=0.42; p=0.03, respectively).

Conclusion

This study demonstrates, for the first time, that high PTPN13 expression level is a prognostic indicator of favorable outcome in patients with HGSOC. This finding, in conjunction with our previous mechanistic studies, suggests that PTPN13 loss, possibly by 4q LOH, enhances HGSOC aggressiveness and highlight the interest of studying PTPN13 signaling in HGSOC to identify new potential therapeutic targets.

Final results of the international randomized PORTEC-3 trial of adjuvant chemotherapy and radiation therapy (RT) versus RT alone for women with high-risk endometrial cancer

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Background: Women with high-risk endometrial cancer (HREC) are at increased risk of distant metastasis and endometrial cancer-related death. The randomized PORTEC-3 intergroup trial was initiated to investigate the benefit of adjuvant chemotherapy during and after radiotherapy (CTRT) versus pelvic radiotherapy (RT) alone for women with HREC. Methods: Women with HREC (FIGO stage I grade 3 with deep myometrial invasion and/or LVSI; stage II or III; or serous/clear cell histology) were randomly allocated (1:1) to RT (48.6 Gy in 1.8 Gy fractions) or CTRT (two cycles of cisplatin 50 mg/m² in week 1 and 4 of RT, followed by four cycles of carboplatin AUC5 and paclitaxel 175 mg/m² at 3-week intervals) with stratification for participating center, lymphadenectomy, stage, and histological type. The co-primary endpoints were overall survival (OS) and failure-free survival (FFS). The Kaplan-Meier method, log-rank test and Cox regression analysis were used for final analysis according to intention-to-treat. PORTEC-3 is registered with ISRCTN (ISRCTN14387080) and ClinicalTrials.gov (NCT00411138). Results: 686 women were enrolled between 2006 and 2013. 26 women were excluded; 13 withdrew consent early and 13 were ineligible, which left 660 patients in the analysis, with a median follow up time of 60.2 months (IQR 47.1–72.9): 330 CTRT and 330 RT. Three- and five-year OS for CTRT vs. RT was 84.4% versus 83.9%, and 81.8% versus 76.7%; overall HR 0.79 [95% CI 0.57-1.12, p=0.183]. Three-year FFS was 79.7% (CTRT) versus 71.8% (RT), and at 5 years 75.5% versus 68.9%, overall HR for FFS 0.77 [0.58-1.03, p=0.078]. Patients with stage III EC had lower 5-year FFS and OS compared to stage I-II (FFS 63.9% vs 78.9%, p<0.001, and OS 74.3% vs 83.1%, p=0.003). They also had greatest benefit of CTRT: 5-year FFS for stage III was 69.3% for CTRT vs 58.0% for RT [95% CI 0.45-0.97, p=0.032], and 5-year OS for stage III was 78.7 % vs 69.8% (p=0.114). Conclusions: Adjuvant chemotherapy given during and after pelvic radiotherapy for treatment of HREC did not significantly improve 5-year FFS and OS, compared with RT alone. For women with stage III EC FFS was however significantly improved with CTRT by 11% at 5 years. Follow-up will continue to evaluate long-term outcomes. Clinical trial information: NCT00411138.

lncRNAs as Novel Indicators of Patients' Prognosis in Stage I Epithelial Ovarian Cancer: A Retrospective and Multicentric Study

Purpose: Stage I epithelial ovarian cancer (EOC) represents about 10% of all EOCs and is characterized by good prognosis with fewer than 20% of patients relapsing. As it occurs less frequently than advanced-stage EOC, its molecular features have not been thoroughly investigated. We have demonstrated that in stage I EOC miR-200c-3p can predict patients' outcome. In the present study, we analyzed the expression of long non-coding RNAs (lncRNA) to enable potential definition of a non-coding transcriptional signature with prognostic relevance for stage I EOC.Experimental Design: 202 snap-frozen stage I EOC tumor biopsies, 47 of which relapsed, were gathered together from three independent tumor tissue collections and subdivided into a training set (n = 73) and a validation set (n = 129). Median follow up was 9 years. LncRNAs' expression profiles were correlated in univariate and multivariate analysis with overall survival (OS) and progression-free survival (PFS).Results: The expression of lnc-SERTAD2-3, lnc-SOX4-1, lnc-HRCT1-1, and PVT1 was associated in univariate and multivariate analyses with relapse and poor outcome in both training and validation sets (P < 0.001). Using the expression profiles of PVT1, lnc-SERTAD2-3, and miR-200c-3p simultaneously, it was possible to stratify patients into high and low risk. The OS for high- and low-risk individuals are 36 and 123 months, respectively (OR, 15.55; 95% confidence interval, 3.81-63.36).Conclusions: We have identified a non-coding transcriptional signature predictor of survival and biomarker of relapse for stage I EOC. Clin Cancer Res; 23(9); 2356-66. ©2016 AACR.

Long non-coding RNAs, ASAP1-IT1, FAM215A, and LINC00472, in epithelial ovarian cancer

OBJECTIVE

Long non-coding RNAs (lncRNAs) are a class of non-protein coding transcripts that has gained significant attention lately due to their important biological actions and potential involvement in cancer. Ovarian cancer is a devastating disease with poor prognosis, and our understanding of lncRNA's involvement in the malignancy is limited. To further our knowledge, we measured the expression of three lncRNAs, ASAP1-IT1, FAM215A, and LINC00472, in tumor samples, and analyzed their associations with disease characteristics and patient survival.

METHODS

Two hundred sixty-six patients diagnosed with primary epithelial ovarian cancers were recruited for the study. Fresh-frozen tumor samples were obtained from the patients at tumor resection and analyzed by RT-qPCR for expression of ASAP1-IT1, FAM215A, and LINC00472. Associations of lncRNA expression with patient survival were determined using Cox proportional hazards regression models.

RESULTS

We observed high expression of ASAP1-IT1, FAM215A and LINC00472 more frequently in low grade tumors and early stage disease compared to high grade tumors and late stage disease, respectively. High expression of ASAP1-IT1 and FAM215A were associated with favorable overall survival, and the survival association with ASAP1-IT1 was independent of tumor grade and disease stage. Analyses of online data also demonstrated similar survival associations with ASAP1-IT1 and FAM215A, suggesting that these lncRNAs may be involved in ovarian cancer progression.

CONCLUSIONS

LncRNAs may play appreciable roles in ovarian cancer and more research is needed to elucidate their biological mechanisms and clinical implications in tumor characterization as well as disease prognosis and treatment.

Toxicity and quality of life after adjuvant chemoradiotherapy versus radiotherapy alone for women with high-risk endometrial cancer (PORTEC-3): an open-label, multicentre, randomised, phase 3 trial

BACKGROUND

About 15% of patients with endometrial cancer have high-risk features and are at increased risk of distant metastases and endometrial cancer-related death. We designed the PORTEC-3 trial to investigate the benefit of adjuvant chemoradiotherapy compared with radiotherapy alone for women with high-risk endometrial cancer.

METHODS

PORTEC-3 was a multicentre, open-label, randomised, international trial. Women with high-risk endometrial cancer were randomly allocated (1:1) to radiotherapy alone (48·6 Gy) in 1·8 Gy fractions five times a week or chemoradiotherapy (two cycles concurrent cisplatin 50 mg/m(2) and four adjuvant cycles of carboplatin area under the curve [AUC] 5 and paclitaxel 175 mg/m(2)) using a biased coin minimisation procedure with stratification for participating centre, lymphadenectomy, stage of cancer, and histological type. The primary endpoints of the PORTEC-3 trial were overall survival and failure-free survival analysed in the intention-to-treat population. This analysis focuses on 2-year toxicity and health-related quality of life as secondary endpoints; analysis was done according to treatment received. Health-related quality of life was assessed with the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire Core 30 (EORTC QLQ-C30) the cervix cancer module and chemotherapy and neuropathy subscales of the ovarian cancer module at baseline, after radiotherapy and at 6, 12, 24, 36, and 60 months after randomisation. Adverse events were graded with Common Terminology Criteria for Adverse Events version 3.0. The study was closed on Dec 20, 2013, after achieving complete accrual, and follow-up remains ongoing for the primary outcomes analysis. This trial is registered with ISRCTN.com, number ISRCTN14387080, and with ClinicalTrials.gov, number NCT00411138.

FINDINGS

Between Sept 15, 2006, and Dec 20, 2013, 686 women were randomly allocated in the PORTEC-3 trial. Of these, 660 met eligibility criteria, and 570 (86%) were evaluable for health-related quality of life. Median follow-up was 42·3 months (IQR 25·8-55·1). At completion of radiotherapy and at 6 months, EORTC QLQ-C30 functioning scales were significantly lower (worse functioning) and health-related quality of life symptom scores higher (worse symptoms) for the chemoradiotherapy group compared with radiotherapy alone, improving with time. At 12 and 24 months, global health or quality of life was similar between groups, whereas physical functioning scores remained slightly lower in patients who received chemoradiotherapy compared with patients who received radiotherapy alone. At 24 months, 48 (25%) of 194 patients in the chemoradiotherapy group reported severe tingling or numbness compared with 11 (6%) of 170 patients in the radiotherapy alone group (p<0·0001). Grade 2 or worse adverse events were found during treatment in 309 (94%) of 327 patients in the chemoradiotherapy group versus 145 (44%) of 326 patients in the radiotherapy alone group, and grade 3 or worse events were found in 198 (61%) of 327 patients in the chemoradiotherapy group versus 42 (13%) of 326 patients in the radiotherapy alone group (p<0·0001), with most of the grade 3 adverse events being haematological (45%). At 12 and 24 months, no significant differences in grade 3 or worse adverse events were found between groups; only grade 2 or higher sensory neuropathy adverse events persisted at 24 months (25 [10%] of 240 patients in the chemoradiotherapy group vs one [<1%] of 247 patients in the radiotherapy alone group; p<0·0001).

INTERPRETATION

Despite the increased physician and patient-reported toxicities, this schedule of adjuvant chemotherapy given during and after radiotherapy in patients with high-risk endometrial cancer is feasible, with rapid recovery after treatment, but with persistence of patient-reported sensory neurological symptoms in 25% of patients. We await the analysis of primary endpoints before final conclusions are made.

FUNDING

Dutch Cancer Society, Cancer Research UK, National Health and Medical Research Council, Project Grant, Cancer Australia Grant, Italian Medicines Agency, and Canadian Cancer Society Research Institute.

Abstract LB-042: Xenopatients help in redefining medical therapeutic algorithms in high risk ovarian cancer

Platinum-based chemotherapy is the recommended first-line treatment for high-grade serous (HGS) epithelial ovarian cancer (EOC). However, most patients relapse because of platinum refractory/resistant disease. We aimed at assessing whether other drugs, commonly used to treat relapsed HGS-EOC and poorly active in this clinical setting, might be more effective against chemotherapy-naïve cancers. We collected samples of advanced HGS-EOC from the same patients before and after neo-adjuvant platinum-based chemotherapy. Samples were propagated as Patient Derived Xenografts (PDXs) in immunocompromised mice (“xenopatients”). Xenopatients were treated with carboplatin, gemcitabine, pegylated liposomal doxorubicin (PLD) and trabectedin. One patient was studied who experienced clinically platinum-sensitivity first and then discordant responses of different tumor sites to platinum re-challenge. PDXs derived from this patient before chemotherapy showed responsiveness to carboplatin, trabectedin and gemcitabine. The PDXs from the same patient after chemotherapy did no longer respond to trabectedin and gemcitabine and showed a heterogeneous response to carboplatin. Expression profiling showed that loss of responsiveness to drugs of the post-chemotherapy PDXs was associated with the up-regulation of NR2F2 gene expression. A second patient with platinum refractory HGS-EOC responded poorly to PLD as second-line treatment. PDXs obtained from this patient's tumor before chemotherapy showed a complete response to PLD, which was lost in the post-chemotherapy PDXs. Response to PLD was associated with the over-expression of the TOP2A protein, which was lost in the post-chemotherapy PDXs. Thus, PDXs demonstrated that chemotherapy-naïve HGS-EOC might display susceptibility to agents not used commonly as first line treatment. These data suggest the importance of tailoring chemotherapy.

Citation Format: Jessica Erriquez, Martina Olivero, Gloria Mittica, Maria Stella Scalzo, Marco Vaira, Michele De Simone, Riccardo Ponzone, Dionyssios Katsaros, Massimo Aglietta, Raffaele Calogero, Maria Flavia Di Renzo, Giorgio Valabrega. Xenopatients help in redefining medical therapeutic algorithms in high risk ovarian cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr LB-042.

A prognostic regulatory pathway in stage I epithelial ovarian cancer: new hints for the poor prognosis assessment

BACKGROUND

Clinical and pathological parameters of patients with epithelial ovarian cancer (EOC) do not thoroughly predict patients' outcome. Despite the good outcome of stage I EOC compared with that of stages III and IV, the risk assessment and treatments are almost the same. However, only 20% of stage I EOC cases relapse and die, meaning that only a proportion of patients need intensive treatment and closer follow-up. Thus, the identification of cell mechanisms that could improve outcome prediction and rationalize therapeutic options is an urgent need in the clinical practice.

PATIENTS AND METHODS

We have gathered together 203 patients with stage I EOC diagnosis, from whom snap-frozen tumor biopsies were available at the time of primary surgery before any treatment. Patients, with a median follow-up of 7 years, were stratified into a training set and a validation set.

RESULTS AND CONCLUSIONS

Integrated analysis of miRNA and gene expression profiles allowed to identify a prognostic cell pathway, composed of 16 miRNAs and 10 genes, wiring the cell cycle, 'Activins/Inhibins' and 'Hedgehog' signaling pathways. Once validated by an independent technique, all the elements of the circuit resulted associated with overall survival (OS) and progression-free survival (PFS), in both univariate and multivariate models. For each patient, the circuit expressions have been translated into an activation state index (integrated signature classifier, ISC), used to stratify patients into classes of risk. This prediction reaches the 89.7% of sensitivity and 96.6% of specificity for the detection of PFS events. The prognostic value was then confirmed in the external independent validation set in which the PFS events are predicted with 75% sensitivity and 94.7% specificity. Moreover, the ISC shows higher classification performance than conventional clinical classifiers. Thus, the identified circuit enhances the understanding of the molecular mechanisms lagging behind stage I EOC and the ISC improves our capabilities to assess, at the time of diagnosis, the patient risk of relapse.