Abstract 3641: The predictive and prognostic roles of DNA damage response genes in epithelial ovarian cancer

Background: Despite platinum-based chemotherapy, 5-year survival of advanced stage ovarian cancer patients is only 15-30%. Exposure to platinum-based chemotherapeutics induces double strand DNA breaks (DSBs) and subsequently leads to activation of the DNA damage response (DDR). Therefore inhibition of components of the DDR may lead to better response to therapy. Aim of this study was to investigate in a large series of ovarian cancer patients the predictive and prognostic role of the activation status of four DDR-proteins- ATM, a key controller in the DDR, and three ATM substrates, including Chk2, 53BP1 and γ-H2AX, of which the latter is a direct readout for DNA damage. Methods: Expression of phospho-ATM, Chk2, phospho-Chk2, 53BP1, phospho-53BP1 and γ-H2AX was immunohistochemically assessed in 309 patients with chemo-naive ovarian cancer. Expression levels were related to clinicopathological characteristics and survival. Response to platinum-based chemotherapy was analyzed by defining two populations with either an optimal therapy response or a very poor therapy response. Both groups consisted of patients with advanced stage ovarian cancer, >2 cm residual disease after primary surgery and were all treated with platinum-based chemotherapy. The responder group had a well-defined PFS of more than 18 months while the non-responder group had a PFS of less than 6 months. Results: In the two well-defined groups with the largest contrast regarding response to treatment, positive γ-H2AX expression (OR=0.193; p=0.036) and positive Chk2 expression (OR=0.149; p=0.011) were related to a good response to platinum-based chemotherapy. In advanced stage patients, phospho-53BP1 expression was independently related to a worse disease-specific survival (HR=1.905; p= 0.044). Conclusion: High DDR protein expression in advanced stage ovarian cancers suggests a high degree of genomic instability, while the negative prognostic impact of phospho-53BP1 may be due to enhanced repair capacity of chemotherapy-induced DSBs on the long term.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3641. doi:1538-7445.AM2012-3641

The role of ATM and 53BP1 as predictive markers in cervical cancer

Treatment of advanced-stage cervical cancers with (chemo)radiation causes cytotoxicity through induction of high levels of DNA damage. Tumour cells respond to DNA damage by activation of the 'DNA damage response' (DDR), which induces DNA repair and may counteract chemoradiation efficacy. Here, we investigated DDR components as potential therapeutic targets and verified the predictive and prognostic value of DDR activation in patients with cervical cancer treated with (chemo)radiation. In a panel of cervical cancer cell lines, inactivation of ataxia telangiectasia mutated (ATM) or its substrate p53-binding protein-1 (53BP1) clearly gave rise to cell cycle defects in response to irradiation. Concordantly, clonogenic survival analysis revealed that ATM inhibition, but not 53BP1 depletion, strongly radiosensitised cervical cancer cells. In contrast, ATM inhibition did not radiosensitise non-transformed epithelial cells or non-transformed BJ fibroblasts. Interestingly, high levels of active ATM prior to irradiation were related with increased radioresistance. To test whether active ATM in tumours prior to treatment also resulted in resistance to therapy, immunohistochemistry was performed on tumour material of patients with advanced-stage cervical cancer (n = 375) treated with (chemo)radiation. High levels of phosphorylated (p-)ATM [p = 0.006, hazard ratio (HR) = 1.817] were related to poor locoregional disease-free survival. Furthermore, high levels of p-ATM predicted shorter disease-specific survival (p = 0.038, HR = 1.418). The presence of phosphorylated 53BP1 was associated with p-ATM (p = 0.001, odds ratio = 2.206) but was not related to any clinicopathological features or survival. In conclusion, both our in vitro and patient-related findings indicate a protective role for ATM in response to (chemo)radiation in cervical cancer and point at ATM inhibition as a possible means to improve the efficacy of (chemo)radiation.

Abstract 4171: The role of ATM and 53BP1 as predictive markers and therapeutic targets in advanced stage cervical cancer

Chemoradiation is the standard of care for advanced stage cervical cancer patients and induces cytotoxicity by inducing high levels of DNA breaks in the tumor. The ability of tumor cells to repair therapy-induced DNA damage may counteract the effects of chemoradiation. The pathway responsible for DNA double strand break repair is called the ‘DNA damage response’.

In vitro we observed robust radiation-induced G1 and G2 cell cycle arrests in cervical cancer cell lines, despite the expression of HPV oncogenes, which impact the DNA damage response through rapid p53 degradation. Moreover, the DNA damage checkpoint protein ATM and its substrate 53BP1 are required for proper induction of cell cycle checkpoint arrests. Yet, when long-term survival effects were measured, inhibition of ATM, but not 53BP1, strongly sensitized cervical cancer cells to irradiation. To validate the putative role of ATM and 53BP1 in advanced stage cervical cancer we investigated presence and activity of ATM as well as 53BP1 in relation to response-to-treatment in a large, well documented, series of advanced stage cervical cancer patients (n=375). We found that high levels of ATM were related to poor response to chemoradiation (P=0.013). Importantly, high phosho-ATM immunostaining, reflecting active ATM, predicted poor responses to chemoradiation even better (P=0.004). In addition, high phospho-ATM levels predicted shorter disease-specific survival (P=0.020).

Although presence of phosphorylated 53BP1 did relate to phospho-ATM (P=0.001), it was not significantly related to any clinicopathological features or survival.

Combined, our data suggest the prognostic value of ATM signaling for responses to chemoradiation and point at ATM inhibition as a potential therapeutic target to increase treatment efficacy in advanced stage cervical cancers.

Acknowledgements

This research is supported by the Dutch Cancer Society (RUG 2007-3719) and the Netherlands Organization for Scientific Research (NWO-VENI 916.76.062).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4171. doi:10.1158/1538-7445.AM2011-4171

Involvement of the TGF-beta and beta-catenin pathways in pelvic lymph node metastasis in early-stage cervical cancer

PURPOSE

Presence of pelvic lymph node metastases is the main prognostic factor in early-stage cervical cancer patients, primarily treated with surgery. Aim of this study was to identify cellular tumor pathways associated with pelvic lymph node metastasis in early-stage cervical cancer.

EXPERIMENTAL DESIGN

Gene expression profiles (Affymetrix U133 plus 2.0) of 20 patients with negative (N(0)) and 19 with positive lymph nodes (N(+)), were compared with gene sets that represent all 285 presently available pathway signatures. Validation immunostaining of tumors of 274 consecutive early-stage cervical cancer patients was performed for representatives of the identified pathways.

RESULTS

Analysis of 285 pathways resulted in identification of five pathways (TGF-β, NFAT, ALK, BAD, and PAR1) that were dysregulated in the N(0), and two pathways (β-catenin and Glycosphingolipid Biosynthesis Neo Lactoseries) in the N(+) group. Class comparison analysis revealed that five of 149 genes that were most significantly differentially expressed between N(0) and N(+) tumors (P < 0.001) were involved in β-catenin signaling (TCF4, CTNNAL1, CTNND1/p120, DKK3, and WNT5a). Immunohistochemical validation of two well-known cellular tumor pathways (TGF-β and β-catenin) confirmed that the TGF-β pathway (positivity of Smad4) was related to N(0) (OR: 0.20, 95% CI: 0.06-0.66) and the β-catenin pathway (p120 positivity) to N(+) (OR: 1.79, 95%CI: 1.05-3.05).

CONCLUSIONS

Our study provides new, validated insights in the molecular mechanism of lymph node metastasis in cervical cancer. Pathway analysis of the microarray expression profile suggested that the TGF-β and p120-associated noncanonical β-catenin pathways are important in pelvic lymph node metastasis in early-stage cervical cancer.

Prognostic significance of tumor-infiltrating T-lymphocytes in primary and metastatic lesions of advanced stage ovarian cancer

PURPOSE

Ovarian cancer patients with intra-tumoral CD3(+) T-lymphocytes in primary tumor tissue have a better prognosis. This study aims to analyze the presence and relative influence of three important T-lymphocyte subsets, tumor-infiltrating CD8(+) cytotoxic T-lymphocytes (CTL), CD45R0(+) memory T-lymphocytes, and FoxP3(+) regulatory T-lymphocytes (Treg), in primary tumor tissue and omental metastases of patients with ovarian cancer.

EXPERIMENTAL DESIGN

The number of CD8(+), CD45R0(+), and FoxP3(+) T-lymphocytes was determined by immunohistochemistry on a tissue micro array containing ovarian tumor tissue and/or omental metastases obtained at primary debulking surgery from 306 FIGO stage I-IV ovarian cancer patients. Immunohistochemistry data were correlated to clinicopathological parameters and survival data.

RESULTS

High number of CD8(+) CTL and a high CD8(+)/FoxP3(+) ratio in ovarian-derived tumor tissue were associated with increased disease-specific survival and proved to be independent prognostic factors in multivariate analyses. In advanced stage patients, the presence of CD8(+) CTL, CD45R0(+) memory T-lymphocytes, FoxP3(+) Treg or a high CD8(+)/FoxP3(+) ratio in ovarian-derived tumor tissue was associated with an increased disease specific survival in univariate analysis, as was the presence of CD45R0(+) memory T-lymphocytes and FoxP3(+) Treg in omental metastases. Furthermore, in advanced stage patients CD8(+) cytotoxic and FoxP3(+) regulatory T-lymphocytes infiltrating ovarian-derived tumor tissue were independent predictors of increased prognosis.

CONCLUSIONS

T-lymphocytes infiltrating primary and metastatic ovarian cancer sites are associated with improved prognosis. These associations are especially distinct in advanced stage patients, underlining the potential for immunotherapy as a broadly applicable therapeutic strategy.

A robust ex vivo model for evaluation of induction of apoptosis by rhTRAIL in combination with proteasome inhibitor MG132 in human premalignant cervical explants

Development of medical therapies for high-grade cervical intraepithelial neoplasia (CIN II/III) is hampered by the lack of CIN II/III cell lines. Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induces apoptosis upon binding to its receptors DR4 or DR5. Proteasome inhibition by MG132 sensitized cervical cancer cell lines to recombinant human (rh)TRAIL. In our study, we aimed to develop an ex vivo model for CIN II/III and to investigate the apoptosis-inducing effect of rhTRAIL and/or MG132 in cervical explants from CIN II/III patients. A short-term ex vivo culture system was optimized for cervical biopsies, in which explants from normal cervix and CIN II/III lesions were exposed to either rhTRAIL (1 microg/ml), MG132 (5 microM) or the combination and compared to untreated explants for apoptosis induction. Normal cervix (n = 90) and CIN II/III (n = 24) explants could be reproducibly put in culture and kept viable for up to 7 days using a transwell membrane system. CIN II/III explants (n = 5) were highly sensitive to rhTRAIL plus MG132 (mean % apoptosis: 91 +/- 5) compared to normal cervix (n = 10) treated with rhTRAIL plus MG132 (mean % apoptosis: 24 +/- 10, p < 0.0001), while monotherapy with either rhTRAIL, MG132 or medium resulted in a mean % apoptosis <10 in both CIN II/III and normal cervix. Our ex vivo model system allows preclinical evaluation of (topical) medical therapies for CIN II/III. A strong synergistic apoptosis-inducing effect of the combination of rhTRAIL and MG132, especially in CIN II/III lesions indicates that rhTRAIL combined with proteasome inhibitors deserves exploration as medical treatment for CIN II/III.

Serum Cytokine Profiling as a Diagnostic and Prognostic Tool in Ovarian Cancer: A Potential Role for Interleukin 7

PURPOSE

To evaluate if serum cytokine levels could be used as diagnostic or prognostic markers in ovarian cancer.

EXPERIMENTAL DESIGN

A cytokine bead array was done to simultaneously analyze 14 cytokines in the sera of 187 ovarian cancer patients with complete clinicopathologic data and follow-up, 45 patients with benign ovarian tumors, and 50 healthy controls. Serum levels of the well-known serum tumor marker CA-125 were routinely measured in all patients.

RESULTS

Serum levels of CA-125, interleukin 6 (IL-6), IL-7, and IL-10 were elevated in ovarian cancer patients compared with patients with benign ovarian tumors. Analyzing the cytokines in combination with CA-125 showed that a combination of IL-7 and CA-125 serum levels could accurately predict 69% of the ovarian cancer patients, without falsely classifying patients with benign pelvic mass. The cytokines IL-6, IL-7, IL-8, IL-10, monocyte chemotactic protein-1 (MCP-1), and IP-10 and CA-125 were associated with disease-free and overall survival in univariate analysis. In multivariate analysis, IL-7 and IP-10 were independent predictors of overall survival, although after inclusion of the clinicopathologic parameters, only stage and residual disease remained as independent predictors of survival.

CONCLUSIONS

IL-7 levels were found to be strongly associated with ovarian cancer and could be used in combination with CA-125 to distinguish between malignant and benign ovarian tumors.

Lymphvascular space involvement: an independent prognostic factor in endometrial cancer

PURPOSE OF INVESTIGATION

To evaluate whether lymphvascular space involvement (LVSI) is a risk factor for relapse of disease and lymph node metastasis in endometrial cancer.

METHODS

From 1978 till 2003, 609 patients with epithelial endometrial cancer were treated at the Groningen University Medical Center. The association of LVSI and relapse of disease was evaluated in the total group of 609 patients and in a 'low' and 'high' risk stage I endometrial cancer group. In 239 surgically staged patients, the relation of LVSI and lymph node metastasis was investigated.

RESULTS

The median age at diagnosis was 63 years (range 27-92 years) with a median follow-up of 58 months (range 0-236 months). More than half of the patients (56%) received adjuvant radiotherapy. LVSI was present in 123 patients (25,6%), and a prognostic factor for relapse of disease (multivariate analysis, P < 0.0001). In the 'low' and 'high' risk stage I endometrial cancer patients an increase of 2.6 times in relapse of disease was observed in the presence of LVSI. LVSI positive tumors were more likely to have metastasized to the pelvic lymph nodes (multivariate analysis, P = 0.001). In patients with proven negative nodes, LVSI was a prognostic factor for relapse of disease (univariate analysis, P = 0.02).

CONCLUSION

LVSI is a predictor of nodal disease and an independent prognostic factor for relapse of disease in all stages of endometrial cancer. Patients with stage I endometrial cancer with positive LVSI are at risk for relapse of disease and might therefore benefit from adjuvant therapy.

CONTENT

The presence of lymphvascular space involvement (LVSI) in endometrial cancer is significantly and independently associated with an increased risk of pelvic lymph node metastases and/or relapse of disease.

Toward New Strategies to Select Young Endometrial Cancer Patients for Mismatch Repair Gene Mutation Analysis

Purpose: To determine the frequency of mismatch repair (MMR) gene germline mutations in endometrial cancer patients who were diagnosed at less than 50 years of age; to relate the presence of mutations to family history, histopathologic data, presence of tumor microsatellite instability (MSI), and immunostaining; and to formulate criteria for genetic testing in these patients.

Patients and Methods: Endometrial cancer patients (N = 58), who were diagnosed at less than 50 years of age, were included and questioned about their family history. Mutation analysis of the MLH1, MSH2, and MSH6 genes was performed (denaturing gradient gel electrophoresis and sequence analysis to detect small mutations and multiplex ligation-dependent probe amplification to detect large deletions or duplications). For MSI analysis, five consensus markers were used, and immunostaining of the three MMR proteins was performed.

Results: In five of 22 patients with a positive first-degree family history for hereditary nonpolyposis colorectal cancer (HNPCC)-related cancers, pathogenic germline mutations were found (one MLH1, three MSH2, and one MSH6). Four mutation carriers belonged to families fulfilling the revised Amsterdam criteria. No mutations were found in the 35 patients without such family history (P = .006). MSI was detected in 20 of 57 cancers, among which four were from mutation carriers. In 23 of 51 cancers, one or more MMR protein was absent; in all five mutation carriers, immunostaining indicated the involved MMR gene.

Conclusion: In 23% of the young endometrial cancer patients with at least one first-degree relative with an HNPCC-related cancer, an MMR gene mutation was detected. Therefore, presence of an HNPCC-related cancer in a first-degree relative seems to be an important selection criterion for mutation analysis. Subsequent immunostaining of MMR proteins will point to the gene(s) that should be analyzed.

Serum squamous cell carcinoma antigen and CYFRA 21-1 in cervical cancer treatment

PURPOSE

To analyze whether serum squamous cell carcinoma (SCC) antigen and cytokeratin-19 fragments (CYFRA) levels can assist in selecting patients with locally advanced cervical cancer who will benefit from combined treatment or additive surgery.

METHODS AND MATERIALS

Of 114 patients with cervical cancer Stage IB-IV, the first 39 patients received radiotherapy, the following 75 patients received identical radiotherapy plus concomitant chemotherapy (3 cycles of carboplatin and 5-fluorouracil). SCC antigen and CYFRA 21-1 serum levels were measured before treatment, after therapy, and during follow-up. Baseline tumor markers were related to tumor stage and size and clinical outcome.

RESULTS

Before treatment, SCC antigen was elevated (>1.9 microg/L) in 60% and CYFRA 21-1 (>2.2 microg/L) in 46% of patients. For all patients, disease-free survival (DFS) was better after combined treatment (67% vs. 43%, p < 0.0005). For patients with elevated baseline SCC antigen, DFS was better after combination therapy (67% vs. 27%, p = 0.001) which resulted more frequently in a normal SCC antigen (93% vs. 65%, p = 0.004). In contrast, in those with a normal baseline CYFRA 21-1, combined therapy resulted in a better DFS (p = 0.04). Patients who achieved a normal SCC antigen or CYFRA 21-1 after treatment had a better DFS (respectively 63 vs. 17% and 64 vs. 30%). Elevated SCC antigen posttreatment indicated residual tumor in 11/12 patients (92%), elevated CYFRA 21-1 in 7/10 patients (70%). Forty-seven patients had a tumor recurrence. At recurrence, SCC antigen was raised in 70% and CYFRA 21-1 in 69%.

CONCLUSIONS

In patients with an elevated pretreatment SCC antigen, SCC antigen normalized more frequently with combined treatment and those patients had a better DFS. Elevated SCC antigen or CYFRA 21-1 levels after treatment completion indicated residual tumor in respectively 92% and 70%. The presence of elevated posttreatment levels of SCC antigen or CYFRA 21-1 indicates the need for additional salvage surgery. SCC antigen proved to be superior to CYFRA 21-1 in predicting DFS and disease recurrence.