Xavier Muracciole

Correlation Between O6-Methylguanine-DNA Methyltransferase and Survival in Inoperable Newly Diagnosed Glioblastoma Patients Treated With Neoadjuvant Temozolomide

PURPOSE This phase II study evaluated the efficacy and safety of a 7-day on/7-day off regimen of temozolomide before radiotherapy (RT) in patients with inoperable newly diagnosed glioblastoma. PATIENTS AND METHODS Patients received temozolomide (150 mg/m2/d on days 1 to 7 and days 15 to 21 every 28 days; 7 days on/7 days off) for up to four cycles before conventional RT (2-Gy fractions to a total of 60 Gy) and for four cycles thereafter or until disease progression. The primary end point was tumor response. Tumor tissue from 25 patients was analyzed for O6-methylguanine-DNA methyltransferase (MGMT) expression. RESULTS Twenty-nine patients with a median age of 60 years were treated, and 28 were assessable for response. Seven (24%) of 29 patients had a partial response, nine patients (31%) had stable disease, and 12 patients (41%) had progressive disease. Median progression-free survival (PFS) time was 3.8 months, and median overall survival (OS) time was 6.1 months. Patients with low MGMT expression, compared with patients with high MGMT expression, had a significantly higher response rate (55% v 7%, respectively; P = .004) and improved PFS (median, 5.5 v 1.9 months, respectively; P = .009) and OS (median, 16 v 5 months, respectively; P = .003). The most common grade 3 and 4 toxicities were thrombocytopenia (20%) and neutropenia (17%). CONCLUSION This dose-dense temozolomide regimen resulted in modest antitumor activity with an acceptable safety profile in the neoadjuvant setting, and expression of MGMT correlated with response to temozolomide. However, this treatment approach seems to be inferior to standard concomitant RT plus temozolomide.

PAI-1 and EGFR expression in adult glioma tumors: Toward a molecular prognostic classification

PURPOSE Molecular classification of gliomas is a major challenge in the effort to improve therapeutic decisions. The plasminogen activator system, including plasminogen activator inhibitor type 1 (PAI-1), plays a key role in tumor invasion and neoangiogenesis. Epidermal growth factor receptor (EGFR) is involved in the control of proliferation. The contribution of PAI-1 and EGFR to the survival of gliomas was retrospectively investigated. METHODS AND MATERIALS Fifty-nine adult gliomas treated by neurosurgery and conventional irradiation were analyzed, including 9 low-grade (2) and 50 high-grade (3-4) tumors (WHO classification). PAI-1 was measured on cytosols and EGFR on solubilized membranes using ELISA methods. RESULTS High PAI-1 levels were strongly associated with high histologic grade (p < 0.001) and histologic necrosis (p < 0.001). PAI-1 also correlated positively with patient age (p = 0.05) and negatively with Karnofsky index (p = 0.01). By univariate analysis of the high-grade population, higher PAI-1 (p < 0.0001) and EGFR values (p = 0.02) were associated with shorter overall survival. Only PAI-1 was an independent factor in multivariate analysis. Grade 3 tumors with low PAI-1 (100% 3-year overall survival rate) presented the same clinical outcome as the low-grade tumors. CONCLUSIONS In this prognostic study, PAI-1 and EGFR expression revealed similarities and differences between high-grade gliomas that were not apparent by traditional clinical criteria. These data strongly support that biologic factors should be included in glioma classification and the design of clinical trials to treat more homogeneous populations.

Neural cell adhesion molecule expression in renal cell carcinomas: relation to metastatic behavior

Neural cell adhesion molecule (NCAM), a member of the immunoglobulin superfamily, is expressed by a subgroup of renal cell carcinomas (RCCs) and by a limited number of adult organs, including the central nervous system (CNS) and adrenal gland. Because the major function of NCAM is homophilic adhesion between homotypic and heterotypic cells, we hypothesized that NCAM-expressing RCCs should preferentially metastasize to the CNS and adrenal gland. We did a retrospective immunohistochemical analysis of NCAM expression both in 338 primary renal tumors, including 249 conventional RCCs and 31 metastases of conventional RCCs. In primary renal tumors, NCAM was expressed by only 38 (15.2%) conventional RCCs and by no other histological subtypes of renal tumor. This expression correlated with a higher risk of adrenal and CNS metastases (P <0.001). NCAM expression also correlated with tumor size (P <0.001), renal vein involvement (P = 0.02), perirenal invasion (P = 0.02), and Fuhrman grading (P < 0.001). Finally, patients with NCAM-expressing RCCs had a lower survival rate (P = 0.006), especially in the first 2 years after surgery. NCAM expression is of interest both for evaluating the prognosis of patients with conventional RCCs and for determining a subgroup of patients at high risk for adrenal and CNS metastases.

Adrenomedullin, an autocrine/paracrine factor induced by androgen withdrawal, stimulates 'neuroendocrine phenotype' in LNCaP prostate tumor cells

Neuroendocrine (NE) differentiation in prostate cancer (CaP) has been reported to be an early marker associated with the development of androgen independence. The mechanisms by which CaP acquires NE properties are poorly understood. In this study, a putative role of adrenomedullin (AM) in the NE differentiation was investigated. The expression of AM and AM receptors (calcitonin receptor-like receptor (CRLR)/receptor activity modifying protein-2 and -3 (RAMP2 and RAMP3) was evaluated after experimental manipulation of androgen status. Levels of AM mRNA and immunoreactive AM (ir-AM) increased four- to sevenfold in androgen-sensitive LNCaP cells after androgen withdrawal in vitro and in LNCaP xenografts in animals after castration. Treatment of LNCaP cells with androgen analogue (dihydrotestosterone; 10−9 M) prevented the increase in AM mRNA and ir-AM levels. Interestingly, the expression of CRLR, RAMP2 and RAMP3 is not regulated by androgen status. We demonstrate that in the presence of serum, AM is able to induce an NE phenotype in LNCaP cells via CRLR/RAMP2 and RAMP3, which includes extension of neuritic processes and expression of the neuron-specific enolase (NSE), producing cGMP in a dose-dependent manner, which is mediated by a pertussis toxin-sensitive GTP-binding protein. 8-bromo-cGMP mimicked the effects of AM on cell differentiation. We demonstrate that AM induces a G-kinase Iα translocation to the nucleus. The protein kinase G inhibitor KT-5823 inhibited the neurite outgrowth induced by both AM and 8-bromo-cGMP. In noncastrated animals, administration of AM enhanced expression of NSE and chromogranin A in LNCaP xenografts with a significant increase of NSE levels in serum and no changes in tumor growth. In castrated animals, intraperitoneal injection of AM resulted in a 240±18% (P<0.001) increase in tumor volume 36 days after treatment, indicating that the nature of effect of AM in CaP depends on the presence or absence of endogenous androgen. Together, these results demonstrate that AM may function as a mediator of NE-like differentiation in culture as well as in vivo and indicate that its production may be important for tumor resurgence following androgen ablation.

Radiosurgery and Carcinogenesis Risk

The definition of radiation-induced tumors is based on indirect criteria. They were defined initially by Cahan: the tumors must occur at the irradiated site after a time of latency longer than 5 years and be of a different pathological type from the initially irradiated tumor. The central nervous system belongs to sensitive tissue and it seems that a threshold dose does not exist. Thus, the relative risk varies from 1.57 to 8.75 for a dose of 1 Gy. It increases with the time of observation with a maximum of 18.4 between 20 and 25 years. Thus the cerebral radiation-induced tumors would be dependent on low dose for large volumes of healthy cerebral tissue (tineas, acute leukemia), and high dose for small volumes as irradiated benign lesions (pituitary tumors, meningiomas). Several factors influence the incidence of these radiation-induced tumors, of which the age at exposure and individual susceptibility are related to heredity. To date, 3 cases of radio-associated glioblastoma and 5 cases of transformed vestibular schwannoma related to radiosurgery were reported in the literature. They do not present all the traditional criteria. Thus, we reported through our experience 2 cases illustrating these problems to confront them with the published data. The long-term risk of radiation-induced tumor requires a time of observation between 5 and 30 years. This risk is estimated at less than 1 per 1,000. It must be communicated to each patient and counterbalanced with the operational risk of a benign tumor (1 per 100 of perioperative mortality) or the hemorrhagic risk of an untreated arteriovenous malformation (1 per 100 per year).

Molecular analysis integrating different pathways associated with androgen-independent progression in LuCaP 23.1 xenograft

After therapeutic hormone deprivation, most prostate cancer (PrCa) cells develop androgen-independent (AI) growth. PrCa is highly heterogeneous and multifocal, suggesting that several molecular processes or pathways may be contributing to AI. The human LuCaP 23.1 xenograft model retains clinical hallmarks of PrCa, including heterogeneous growth, PSA production, androgen-responsiveness and progression to AI. In this work, we studied the effect of androgen depletion (castration) on the growth of LuCaP 23.1 xenografts. A total of 100 nude mice were implanted and analysed for their growth profiles before and after castration. By 11 and 15 weeks, tumours were harvested and assessed for molecular marker expression specific for PrCa. Prior to castration we found 37 fast growing (FG) tumours (948.9±76.9 mm3) and 63 slow growing (SG) tumours (229.6±18.4 mm3), a previously undescribed result for this PrCa model. Quantitative RT–PCR showed that in comparison to SGs, FGs contained high HER1, uPA and thymidilate synthetase (TS) expression with low levels of 5α-reductase 2 mRNA. All FG tumours progressed rapidly to AI growth 5 weeks after castration (FG-P). In SG castrated tumours, 66% of tumours (SG-P) showed retarded progression (by 12 weeks) to AI, whereas 34% responded to castration (SG-R). Molecular analysis permitted us to define distinct molecular profiles integrating different pathways associated with AI progression. FG-P, and a subgroup of SG-P tumours, presented significantly high levels of peptidylglycine α-amidating monooxygenase (PAM), HER1, HER2, TS, and uPA mRNA, all of which correlated with AR expression. The second subgroup of SG-P tumours showed overexpression of the antiapoptotic gene Bcl-2. A third subgroup of SG-P tumours showed significant expression of hypoxia-related gene (adrenomedullin) after castration. This work permitted to define distinct molecular profiles related to different AI growth in the LuCaP 23.1 xenograft.

Mathematical modeling of cancer immunotherapy and its synergy with radiotherapy

Combining radiotherapy with immune checkpoint blockade may offer considerable therapeutic impact if the immunosuppressive nature of the tumor microenvironment (TME) can be relieved. In this study, we used mathematical models, which can illustrate the potential synergism between immune checkpoint inhibitors and radiotherapy. A discrete-time pharmacodynamic model of the combination of radiotherapy with inhibitors of the PD1-PDL1 axis and/or the CTLA4 pathway is described. This mathematical framework describes how a growing tumor first elicits and then inhibits an antitumor immune response. This antitumor immune response is described by a primary and a secondary (or memory) response. The primary immune response appears first and is inhibited by the PD1-PDL1 axis, whereas the secondary immune response happens next and is inhibited by the CTLA4 pathway. The effects of irradiation are described by a modified version of the linear-quadratic model. This modeling offers an explanation for the reported biphasic relationship between the size of a tumor and its immunogenicity, as measured by the abscopal effect (an off-target immune response). Furthermore, it explains why discontinuing immunotherapy may result in either tumor recurrence or a durably sustained response. Finally, it describes how synchronizing immunotherapy and radiotherapy can produce synergies. The ability of the model to forecast pharmacodynamic endpoints was validated retrospectively by checking that it could describe data from experimental studies, which investigated the combination of radiotherapy with immune checkpoint inhibitors. In summary, a model such as this could be further used as a simulation tool to facilitate decision making about optimal scheduling of immunotherapy with radiotherapy and perhaps other types of anticancer therapies. Cancer Res; 76(17); 4931-40. ©2016 AACR.

Expression and role of adrenomedullin in renal tumors and value of its mRNA levels as prognostic factor in clear-cell renal carcinoma

Antiangiogenic therapies are used for advanced clear‐cell renal carcinomas (cRCC), but without curative possibilities, underlining the need for new therapeutic targets. Adrenomedullin (AM), a multifunctional peptide, is highly expressed in several tumors and plays an important role in angiogenesis and tumor growth through its receptors: calcitonin receptor‐like receptor/receptor activity‐modifying protein 2 and 3 (CLR/RAMP2 and CLR/RAMP3). In this study, real‐time quantitative reverse‐transcription‐PCR showed AM mRNA levels were higher in cRCC and in chromophobe renal carcinomas (chRCC) than in normal renal tissue. Interestingly, AM mRNA expression in cRCC correlated strongly with VEGF‐A mRNA expression. Immunohistochemically, AM, CLR and RAMP2 were localized in the carcinomatous epithelial compartment of cRCC. Interestingly, RAMP3 immunostaining was found only in the inflammatory cells that infiltrated tumors, suggesting a cross talk between tumor cells and the microenvironment. We also observed that cRCC cells BIZ and 786‐O expressed and secreted AM into the culture medium. In vitro, exogenous AM treatment stimulated cell proliferation, migration and invasion, indicating the cell can respond to AM. The action of AM was specific and was mediated by the CLR/RAMP2 and CLR/RAMP3 receptors. Clinical data showed the prognostic value of AM. High AM mRNA levels were associated with an increased risk of relapse after curative nephrectomy for cRCC. These findings highlight the implication of the AM pathway in the metastatic process and the prognostic relevance of AM in cRCC and point to a potential new therapeutic target.

Gamma Knife Radiosurgery of Brain Metastasis from Breast Cancer

The incidence of brain metastasis in patients with metastatic breast cancer ranges from 14 to 16%.Age, number of metastatic sites, short disease-free survival and molecular subtypes are associated with the occurrence of brain metastasis. Patients classified in the triple-negative group more frequently presented brain metastasis as the first site (26%) than those in the human epidermal growth factor receptor 2 (HER2)-positive (6%) or luminal (12%) subtypes. Whole brain radiation therapy (WBRT) is still the standard treatment for breast cancer patients with brain metastasis. The 1- and 2-year survival rates of patients with brain metastasis were 25 and 10%, respectively, with a median survival of 6 months. In selected patients with single brain metastasis, majority of lung cancer, three randomized controlled trials underlined the significant survival benefit in adding local treatment such as surgery or stereotactic radio surgery to WBRT. Similarly, the upfront stereotactic radiosurgery (SRS) alone did not affect survival rate in three other randomized studies and represents an alternative treatment for patients with stage 1-4. Metastatic breast cancer patients with Karnofsky Performance Scale ≥70, single or oligometastatic brain metastases and well-controlled extracranial disease or favorable disease-specific graded prognostic assessment group presented a median overall survival of 16 months. Delaying WBRT could spare patients of neurocognitive toxicity due to full-dose whole brain irradiation. Nevertheless, the real WBRT neurocognitive impact is still unclear. These patients should be followed with serial magnetic resonance image every 3 months and treated with WBRT or additional SRS at recurrence to control brain disease.

Patterns of failure after radiotherapy for pediatric patients with intracranial ependymoma

PURPOSE To investigate the patterns of failure after radiotherapy for pediatric intracranial ependymoma and their correlation with dose parameters. METHODS Between 2000 and 2013, 206 patients were treated in France. MRI scans at relapse were registered to the original planning CTs for topographic analysis of failure patterns. To compare relapse patients (RP) with non relapse patients (NRP), several dose parameters were derived from dose volume histograms. RESULTS Over a median follow-up of 53.8months, 84 patients presented with relapse. Topographic analysis showed 50 patients with local relapse in the radiation field, 6 in the edge of field, 6 locoregional outside the field, 10 in the spine, 5 supratentorial and 7 local and distant. The median coverage, target coverage and homogeneity indices did not differ significantly between RP and NRP. The median volume of in-field relapse was 1.25cc [0.11, 27], with a median dose of 57.83Gy [50.04, 61.69]. CONCLUSIONS Local relapse in the tumor bed and the higher dose regions was the predominant pattern of failure. Improving coverage of the target volume and increasing the dose to the high radioresistant regions, taking into consideration other clinical and biological pronostic factors, may be an effective way of reducing local failures.