Jayant S. Goda

Neoadjuvant radiotherapy for locally advanced and high-risk prostate cancer.

Men presenting with high-risk or locally advanced prostate cancer may benefit from a combination of radiotherapy and surgery to maximize local control. Adjuvant radiotherapy following surgery has improved biochemical progression-free survival, metastasis-free survival, lengthened the time to hormone therapy use and improved overall survival in three randomized-phase III trials. One surprising result of the Southwest Oncology Group (SWOG) 8794 trial and the European Organisation for Research and Treatment of Cancer (EORTC) 22911 trial is that treatment failure was mainly a result of lack of local control. This finding has led to a new appreciation of local control as a determinant of survival and the role for combined modality approaches within a multidisciplinary team in the treatment of high-risk and locally advanced prostate cancer. One emerging novel approach is the use of preoperative or intraoperative radiotherapy in addition to best surgical and systemic treatments. Preliminary results from clinical trials indicate low rates of intraoperative toxic effects, an advantage of short treatment times and smaller image-guided radiotherapy treatment volumes when compared with postoperative radiotherapy. Potential disadvantages include over-treatment of patients and lack of data on long-term toxic effects. We present the published treatment approaches and rational for preoperative and intraoperative radiotherapy and compare these methods to the utility of postoperative radiotherapy.

Radiation-induced homotypic cell fusions of innately resistant glioblastoma cells mediate their sustained survival and recurrence

Understanding of molecular events underlying resistance and relapse in glioblastoma (GBM) is hampered due to lack of accessibility to resistant cells from patients undergone therapy. Therefore, we mimicked clinical scenario in an in vitro cellular model developed from five GBM grade IV primary patient samples and two cell lines. We show that upon exposure to lethal dose of radiation, a subpopulation of GBM cells, innately resistant to radiation, survive and transiently arrest in G2/M phase via inhibitory pCdk1(Y15). Although arrested, these cells show multinucleated and giant cell phenotype (MNGC). Significantly, we demonstrate that these MNGCs are not pre-existing giant cells from parent population but formed via radiation-induced homotypic cell fusions among resistant cells. Furthermore, cell fusions induce senescence, high expression of senescence-associated secretory proteins (SASPs) and activation of pro-survival signals (pAKT, BIRC3 and Bcl-xL) in MNGCs. Importantly, following transient non-proliferation, MNGCs escape senescence and despite having multiple spindle poles during mitosis, they overcome mitotic catastrophe to undergo normal cytokinesis forming mononucleated relapse population. This is the first report showing radiation-induced homotypic cell fusions as novel non-genetic mechanism in radiation-resistant cells to sustain survival. These data also underscore the importance of non-proliferative phase in resistant glioma cells. Accordingly, we show that pushing resistant cells into premature mitosis by Wee1 kinase inhibitor prevents pCdk1(Y15)-mediated cell cycle arrest and relapse. Taken together, our data provide novel molecular insights into a multistep process of radiation survival and relapse in GBM that can be exploited for therapeutic interventions.

Efficacy of Stereotactic Conformal Radiotherapy vs Conventional Radiotherapy on Benign and Low-Grade Brain Tumors: A Randomized Clinical Trial

Importance Evidence for application of stereotactic and other conformal radiotherapy techniques in treating brain tumors is largely based on data derived from dosimetric, retrospective, or small prospective studies. Therefore, we conducted a randomized clinical trial of stereotactic conformal radiotherapy (SCRT) compared with conventional radiotherapy (ConvRT) evaluating clinically meaningful end points. Objective To compare neurocognitive and endocrine functional outcomes and survival at 5 years in young patients with residual and/or progressive benign or low-grade brain tumors treated with SCRT and ConvRT techniques. Design, Setting, and Participants This phase 3 randomized clinical trial enrolled 200 young patients (ages 3-25 years) with residual or progressive benign or low-grade brain tumors at a single center between April 2001 to March 2012. Patients were randomly allocated (1:1) to either SCRT (n = 104) or ConvRT (n = 96) arms. Interventions Patients were randomly assigned to either high-precision SCRT or ConvRT to a dose of 54 Gy in 30 fractions over 6 weeks. Main Outcomes and Measures Detailed neuropsychological and neuroendocrine assessments were performed at preradiotherapy baseline, at 6 months, and annually thereafter until 5 years on longitudinal follow-up. Change in these functional parameters was compared between the 2 arms as the primary end point and overall survival (OS) as the secondary end point. Results In total, 200 young patients (median [interquartile range] age, 13 [9-17] years; 133 males and 67 females) were enrolled. Mean full-scale or global intelligence quotient (IQ) and performance IQ scores over a period of 5 years were significantly superior in patients treated with SCRT compared with those treated with ConvRT (difference in slope = 1.48; P = .04 vs difference in slope = 1.64; P = .046, respectively). Cumulative incidence of developing new neuroendocrine dysfunction at 5 years was significantly lower in patients treated with SCRT compared with ConvRT (31% vs 51%; P = .01) while developing a new neuroendocrine axis dysfunction in patients with preexisting dysfunction in at least 1 axis at baseline was also significantly lower in the SCRT arm compared with the ConvRT arm (29% vs 52%; P = .02). Five-year OS in SCRT and ConvRT arms was 86% and 91%, respectively (P = .54). Conclusions and Relevance In young patients with residual and/or progressive benign or low-grade brain tumors requiring radiotherapy for long-term tumor control, SCRT compared with ConvRT achieves superior neurocognitive and neuroendocrine functional outcomes over 5 years without compromising survival. Trial Registration clinicaltrials.gov Identifier: NCT00517959

Role of Radiation Therapy in Patients With Relapsed/Refractory Diffuse Large B-Cell Lymphoma: Guidelines from the International Lymphoma Radiation Oncology Group

Approximately 30% to 40% of patients with diffuse large B-cell lymphoma (DLBCL) will have either primary refractory disease or relapse after chemotherapy. In transplant-eligible patients, those with disease sensitive to salvage chemotherapy will significantly benefit from high-dose therapy with autologous stem cell transplantation. The rationale for considering radiation therapy (RT) for selected patients with relapsed/refractory DLBCL as a part of the salvage program is based on data regarding the patterns of relapse and retrospective series showing improved local control and clinical outcomes for patients who received peritransplant RT. In transplant-ineligible patients, RT can provide effective palliation and, in selected cases, be administered with curative intent if the relapsed/refractory disease is localized. We have reviewed the indications for RT in the setting of relapsed/refractory DLBCL and provided recommendations regarding the optimal timing of RT, dose fractionation scheme, and treatment volume in the context of specific case scenarios.

Impact of oligodendroglial component in glioblastoma (GBM-O): Is the outcome favourable than glioblastoma?

BACKGROUND Prognosis of patients with glioblastoma with oligodendroglial component (GBM-O) is not well defined. We report our experience of patients of GBM-O treated at our center. METHODS Between January 2007 and August 2013, out of 817 consecutive patients with glioblastoma (GBM), 74 patients with GBM-O were identified in our prospectively maintained database. An experienced neuropathologist revaluated the histopathology of all these 74 patients and the diagnosis of GBM-O was eventually confirmed in 57 patients. Patients were uniformly treated with maximal safe resection followed by focal radiotherapy with concurrent and adjuvant temozolamide (TMZ). RESULTS At a median follow up of 16 months, median overall survival (OS) and progression free survival (PFS) of the entire cohort was 23 months and 13 months respectively. Near total excision was performed in 30/57 (52.6%). On univariate analysis, age < 50 years was a significant favourable prognostic factor for OS (p = 0.009) and PFS (p = 0.017), while patients with near total resection had a significantly better PFS (p = 0.017), patients who completed a minimum of 6 cycles of adjuvant TMZ had significantly better OS (p = 0.000) and PFS (p = 0.003). On multivariate analysis, none of the above factors were significant except for patient who had completed a minimum of 6 cycles of TMZ (OS; p = 0.000 & PFS; p = 0.015). A comparative analysis of GBM-O patients with a similarly treated cohort of 105 GBM patients during the same period revealed significantly better median OS in favour of GBM-O (p = 0.01). CONCLUSIONS Our experience suggests patients with GBM-O have a more favourable clinical outcome as compared to GBM.

Histological spectrum of oligodendroglial tumors: Only a subset shows 1p/19q codeletion

Background: Canonical oligodendroglial tumors (ODGs) are characterized genetically by chromosomes 1p/19q codeletion. Aims: This study was essentially aimed at the detection of frequency of 1p/19q codeletion in the different histological spectrum of ODG tumors in a large cohort of Indian patients. Materials and Methods: All the ODG tumors evaluated for 1p/19q by fluorescence in-situ hybridization (FISH) during 2009–2015 were correlated with histology, immunohistochemical expression for p53 protein and clinical features. Results: A total of 676 cases included both pediatric (n = 18) and adult (n = 658) patients. Histologically, 346 pure ODGs [oligodendroglioma (OD) and anaplastic oligodendroglioma (AOD)] and 330 mixed ODGs [oligoastrocytomas (OA), anaplastic oligoastrocytomas (AOA) and glioblastoma with oligodendroglioma component (GBM-O)] were included. 1p/19q co-deletion was noted in 69% (60/87), 55.9% (145/259), 18.2% (18/99), 10.5% (18/172), and in 5.1% (3/59) cases of OD, AOD, OA, AOA, and GBM-O, respectively. In the pediatric age-group, 1p/19q codeletion was seen in 25% (2/8) of pure ODGs and in 10% (1/10) of mixed ODGs. In adults, it was observed in 60% (203/338) cases of pure ODGs and in 11.9% (38/320) cases of mixed ODGs. In adults, pure ODG histology (P = 0.00), frontal location (P = 0.004), calcification [in pure ODGs] (P = 0.03), and lack of p53 protein overexpression (P = 0.00) showed significant statistical correlation with 1p/19q codeletion. Conclusions: This study is unique in being one of the largest on ODGs for 1p/19q co-deletion including both pediatric and adult age groups of Indian patients. The results showed co-deletion in 60% of adult ODGs and 25% of pediatric pure ODGs. This reemphasizes the occurrence of 1p/19q codeletion, even though rare, in the pediatric age group.

Toxicological safety evaluation of 3,3′-diselenodipropionic acid (DSePA), a pharmacologically important derivative of selenocystine

ABSTRACT Diselenodipropionic acid (DSePA), a pharmacologically important derivative of selenocystine was evaluated for acute toxicity, mutagenic safety and metabolic stability. The estimated median oral lethal dose (LD50) cut‐off of DSePA in mice and rat models was ˜200 mg/kg and ˜25 mg/kg respectively, which is considerably higher than the reported oral LD50 dose of its parent compound. Subsequently DSePA treatment in absence and presence of rat liver S9 fraction was found to be non‐mutagenic at the tested doses up to 1 mM in rifampicin resistance assay and up to 6 mM in Ames test. In vitro degradation studies indicated that DSePA was more stable in S9 fraction of human compared to rat. The kinetic parameters Km and Vmax of DSePA degradation estimated using rat S9 fraction was 9.81 &mgr;M and 1.06 nmol/ml/min respectively. Further, DSePA treatment (1–50 &mgr;M) with or without rat S9 fraction did not induce any toxicity in human intestinal epithelial cells (Int 407) while showing comparable bioactivity of glutathione peroxidase (GPx) level. In conclusion, superior metabolic stability of DSePA in human S9 fraction with a concomitant lack of mutagenic effects suggests that it may be a suitable derivative of selenocytine for future biological studies. HighlightsLD50 of DSePA (oral) is 200 and 25 mg/kg body‐weight for mice and rat respectively.DSePA is relatively more stable in human S9 fraction compared to rat S9 fraction.DSePA with and without metabolic transformation was found to be non‐mutagenic.S9‐derived degradation of DSePA did not affect its toxicity and bioactivity in cells.

Enhanced proteasomal activity is essential for long term survival and recurrence of innately radiation resistant residual glioblastoma cells

Therapy resistance and recurrence in Glioblastoma is due to the presence of residual radiation resistant cells. However, because of their inaccessibility from patient biopsies, the molecular mechanisms driving their survival remain unexplored. Residual Radiation Resistant (RR) and Relapse (R) cells were captured using cellular radiation resistant model generated from patient derived primary cultures and cell lines. iTRAQ based quantitative proteomics was performed to identify pathways unique to RR cells followed by in vitro and in vivo experiments showing their role in radio-resistance. 2720 proteins were identified across Parent (P), RR and R population with 824 and 874 differential proteins in RR and R cells. Unsupervised clustering showed proteasome pathway as the most significantly deregulated pathway in RR cells. Concordantly, the RR cells displayed enhanced expression and activity of proteasome subunits, which triggered NFkB signalling. Pharmacological inhibition of proteasome activity led to impeded NFkB transcriptional activity, radio-sensitization of RR cells in vitro, and significantly reduced capacity to form orthotopic tumours in vivo. We demonstrate that combination of proteasome inhibitor with radio-therapy abolish the inaccessible residual resistant cells thereby preventing GBM recurrence. Furthermore, we identified first proteomic signature of RR cells that can be exploited for GBM therapeutics.

Study of interaction of GNR with glioblastoma cells

Radiation resistance is one of the major causes of recurrence and failure of radiotherapy. Different methods have been used to increase the efficacy of radiation therapy and at the same time restrict the radiation resistivity. From last few years nanoparticles have played a key role in the enhancement of radiosensitization. The densely packed nanoparticles can selectively scatter or absorb the high radiations, which allow better targeting of cellular components within the tumor hence resulting in increased radiation damage to the cancer cells. Glioblastoma multiforme (GBM) is one of the highly radioresistant brain cancer. Current treatment methods are surgical resection followed by concurrent chemo and radiation therapy. In this study we have used in-house engineered gold nano rodes (GNR) and analyzed their effect on U-87MG cell lines. MTT assay was employed to determine the cytotoxic concentration of the nanoparticles. Raman spectroscopy was used to analyze the effect of gold nanoparticles on glioma cells, which was followed by transmission electron microscopic examinations to visualize their cellular penetration. Our data shows that GNR were able to penetrate the cells and induce cytotoxicity at the concentration of 198 μM as determined by MTT assay at 24 post GNP treatment. Additionally, we show that Raman spectroscopy, could classify spectra between untreated and cells treated with nanoparticles. Taken together, this study shows GNR penetration and cytotoxicity in glioma cells thereby providing a rationale to use them in cancer therapeutics. Future studies will be carried out to study the biological activity of the formulation as a radiosensitizer in GBM.

Molecular features unique to glioblastoma radiation resistant residual cells may affect patient outcome - a short report

PurposePreviously we have shown, using a primary glioblastoma (GBM) cell model, that a subpopulation of innately radiation resistant (RR) GBM cells survive radiotherapy and form multinucleated and giant cells (MNGCs) by homotypic fusions. We also showed that MNGCs may cause relapse. Here, we set out to explore whether molecular characteristics of RR cells captured from patient-derived primary GBM cultures bear clinical relevance.MethodsPrimary cultures were derived from 19 naive GBM tumor samples. RR cells generated from these cultures were characterized using various cell biological assays. We also collected clinicopathological data of the 19 patients and assessed associations with RR variables using Spearman’s correlation test and with patient survival using Kaplan-Meier analysis. Significance was determined using a log-rank test.ResultsWe found that SF2 (surviving fraction 2) values (p = 0.029), days of RR cell formation (p = 0.019) and percentage of giant cells (p = 0.034) in the RR population independently correlated with a poor patient survival. We also found that low ATM (Ataxia-telangiectasia mutated) expression levels in RR cells showed a significant (p = 0.002) negative correlation with SF2 values. A low ATM expression level in RR cells along with a high tumor volume was also found to negatively correlate with patient survival (p = 0.011). Finally, we found that the ATM expression levels in RR cells independently correlated with a poor patient survival (p = 0.014).ConclusionsOur data indicate that molecular features of innately radiation resistant GBM cells independently correlate with clinical outcome. Our study also highlights the relevance of using patient-derived primary GBM cultures for the characterization of RR cells that are otherwise inaccessible for analysis.