Yaacov Lawrence | Tel Aviv University (original) (raw)

Papers by Yaacov Lawrence

International Journal of Radiation Oncology Biology Physics, 2013

Despite recent advances in the management of high-grade and recurrent gliomas, survival remains p... more Despite recent advances in the management of high-grade and recurrent gliomas, survival remains poor. Antiangiogenic therapy has been shown to be efficacious in the treatment of high-grade gliomas both in preclinical models and in clinical trials. We sought to determine the safety and maximum tolerated dose of sorafenib when combined with both radiation and temozolomide in the primary setting or radiation alone in the recurrent setting. This was a preclinical study and an open-label phase I dose escalation trial. Multiple glioma cell lines were analyzed for viability after treatment with radiation, temozolomide, or sorafenib or combinations of them. For patients with primary disease, sorafenib was given concurrently with temozolomide (75 mg/m(2)) and 60 Gy radiation, for 30 days after completion of radiation. For patients with recurrent disease, sorafenib was combined with a hypofractionated course of radiation (35 Gy in 10 fractions). Cell viability was significantly reduced with the combination of radiation, temozolomide, and sorafenib or radiation and sorafenib. Eighteen patients (11 in the primary cohort, 7 in the recurrent cohort) were enrolled onto this trial approved by the institutional review board. All patients completed the planned course of radiation therapy. The most common toxicities were hematologic, fatigue, and rash. There were 18 grade 3 or higher toxicities. The median overall survival was 18 months for the entire population. Sorafenib can be safely combined with radiation and temozolomide in patients with high-grade glioma and with radiation alone in patients with recurrent glioma. The recommended phase II dose of sorafenib is 200 mg twice daily when combined with temozolomide and radiation and 400 mg with radiation alone. To our knowledge, this is the first publication of concurrent sorafenib with radiation monotherapy or combined with radiation and temozolomide.

We prospectively utilized the Dose Verification System with radiopaque MOSFET dosimeters in twent... more We prospectively utilized the Dose Verification System with radiopaque MOSFET dosimeters in twenty patients undergoing IMRT with daily image guidance. Dose measurements consistently higher than 6% above predicted values were observed for 3 of 20 patients and while review of daily IGRT revealed acceptable alignment of the prostate target volumes and implanted dosimeters, significant anatomic changes within the treated region were detected. Repeat CT simulation and radiation planning resulted in resolution of the discrepancy.

$Research paper thumbnail of 216 Phase I study of panobinostat and fractionated stereotactic re-irradiation therapy (FSRT) for recurrent high grade gliomas$

European Journal of Cancer, 2014

British Journal of Cancer, 2011

BACKGROUND: Patients with high-grade gliomas are treated with surgery followed by chemoradiation.... more BACKGROUND: Patients with high-grade gliomas are treated with surgery followed by chemoradiation. The risk factors and implications of neurological side effects are not known. METHODS: Acute and late X grade 3 neurological toxicities (NTs) were analysed among 2761 patients from 14 RTOG trials accrued from 1983 to 2003. The association between acute and late toxicity was analysed using a stepwise logistic regression model. The association between the occurrence of acute NT and survival was analysed as an independent variable. RESULTS: There were 2610 analysable patients (86% glioblastoma, 10% anaplastic astrocytoma). All received a systemic agent during radiation (83% chemotherapy, 17% biological agents). Median radiation dose was 60 Gy. There were 182 acute and 83 late NT events. On univariate analysis, older age, poor performance status, aggressive surgery, pre-existing neurological dysfunction, poor mental status and twice-daily radiation were associated with increased acute NT. In a stepwise logistic regression model the occurrence of acute NT was significantly associated with late NT (OR ¼ 2.40; 95% CI ¼ 1.2 -4.8; P ¼ 0.014). The occurrence of acute NT predicted poorer overall survival, independent of recursive partitioning analysis class (median 7.8 vs 11.8 months). INTERPRETATION: Acute NT is significantly associated with both late NT and overall survival.

Prostate Cancer and Prostatic Diseases, 2013

BACKGROUND: The worldwide incidence of diabetes mellitus is rapidly increasing. There is recent i... more BACKGROUND: The worldwide incidence of diabetes mellitus is rapidly increasing. There is recent interest in the influence of glucose metabolism on oncogenesis. We investigated the role of diabetes mellitus and the metabolic syndrome (MS) on prostate cancer development. METHODS: This study consisted of 11 541 men with coronary heart disease screened to participate in a secondary cardiac prevention trial. MS was defined according to modified NCEP/ATP III criteria. Multivariable regression analysis accounting for competing risks was performed using a modified Cox proportional hazard model in order to assess the association between diabetes, the MS and the subsequent development of prostate cancer. RESULTS: At baseline, subjects were classified into one of the four groups: (1) 6119 (53%) with neither diabetic mellitus nor MS, (2) 3376 (29%) with the MS but without diabetes, (3) 560 (5%) with diabetes mellitus but without MS and (4) 1486 (13%) with both conditions. Median follow-up was 12.7 years (range 0-15.7 years). During follow-up, 459 new cases of prostate cancer were recorded. The age-adjusted hazard ratio (HR) for prostate cancer was reduced in diabetic patients compared with those without diabetes, 0.54 and 95% confidence interval of 0.40-0.73. No significant association was noted between the presence of MS and prostate cancer development. On multivariate analysis, diabetes mellitus continued to protect against the development of prostate cancer, this was more pronounced in the absence of MS (HR ¼ 0.43, P ¼ 0.01 for diabetes in the absence of MS; HR ¼ 0.64, P ¼ 0.08 in the presence of MS). CONCLUSIONS: The results of this study indicate an inverse association between type 2 diabetes mellitus and prostate cancer risk.

The Lancet Oncology, 2008

Hypoxia in prostate cancer: observation to intervention. By - Yaacov Richard Lawrence, Adam P Dic... more Hypoxia in prostate cancer: observation to intervention. By - Yaacov Richard Lawrence, Adam P Dicker.

Journal of Neuro-Oncology, 2014

Perform a phase I study to evaluate the safety, and tolerability of vorinostat, an HDAC inhibitor... more Perform a phase I study to evaluate the safety, and tolerability of vorinostat, an HDAC inhibitor, when combined with whole brain radiation treatment (WBRT) in patients with brain metastasis. A multi-institutional phase I clinical trial enrolled patients with a histological diagnosis of malignancy and radiographic evidence of brain metastasis. WBRT was 37.5 Gy in 2.5 Gy fractions delivered over 3 weeks. Vorinostat was administrated by mouth, once daily, Monday through Friday, concurrently with radiation treatment. The vorinostat dose was escalated from 200 to 400 mg daily using a 3?3 trial design. Seventeen patients were enrolled, 4 patients were excluded from the analysis due to either incorrect radiation dose (n = 1), or early treatment termination due to disease progression (n = 3). There were no treatment related grade 3 or higher toxicities in the 200 and 300 mg dose levels. In the 400 mg cohort there was a grade 3 pulmonary embolus and one death within 30 days of treatment. Both events were most likely related to disease progression rather than treatment; nonetheless, we conservatively classified the death as a dose limiting toxicity. We found Vorinostat administered with concurrent WBRT to be well tolerated to a dose of 300 mg once daily. This is the recommended dose for phase II study.

Journal of Neuro-Oncology, 2012

Optic nerve gliomas (ONG) are rare astrocytic neoplasms. A paucity of literature exists on the ep... more Optic nerve gliomas (ONG) are rare astrocytic neoplasms. A paucity of literature exists on the epidemiology and outcomes of ONG. Here, we present a series of 445 cases of ONG obtained from the Surveillance, epidemiology and end results (SEER) database. Data on patient and tumor characteristics as well as initial treatment with surgery or radiation were extracted from the SEER Database. Survival rates were calculated using the Kaplan-Meier method. A multivariate analysis was performed to determine independent prognostic factors predicting mortality hazard ratios (HRs) using Cox proportional hazards modeling. The median age range at diagnosis was 5-9 years. Twenty percent of patients were over the age of 20 years. Amongst patients with information available on tumor grade (n = 131), 83% had a low-grade tumors and 17% had a high-grade tumors. Sixteen percent of patients received radiation therapy and 18.4% of patient underwent a sub-or gross total resection. The 5 year overall survival was 96% and 20% for patients with low-and high-grade tumors, respectively. In a multivariate analysis, grade was the only significant predictor of overall survival (HR 29.3, CI: 4.3, 205.4, P \ 0.001). Age at diagnosis, receipt of radiation therapy, and extent of surgical resection were not significantly correlated with overall survival. In conclusion, ONG are rare tumors seen predominantly in children. The overall prognosis of high-grade tumors remains poor in all age groups despite multi-modality treatment.

Journal of Medical Imaging and Radiation Oncology, 2013

Introduction: Over one third of cancer patients receive radiation therapy (RT) at some point. Our... more Introduction: Over one third of cancer patients receive radiation therapy (RT) at some point. Our purpose was to quantify the risks to patients associated with enrolment onto RT-based phase I trials. Methods: All phase I and phase I/II clinical trials involving RT published in English between 2001 and 2010 were identified via a PubMed search. For pragmatic reasons, we focused on trials from 2001, 2005 and 2009. For each trial we calculated a 'toxicity ratio' equal to the number of grade 3/4/5 toxic events divided by the number of patients in the trial. Linear regression was used to determine which variables were associated with higher toxicity ratios. Results: There were a total of 33 treatment-related deaths, and 1812 acute grade 3/4 toxicities among the 2994 subjects in 98 trials. The median toxicity ratio over 98 trials was 0.46 (95% confidence interval (CI) 0.34 to 0.58). Multivariate regression analysis showed that toxicity ratios were significantly higher in trials with chemotherapy (P = 0.002) and in trials for cancers of the head-and-neck (P < 0.001). The median toxicity ratio in chemotherapy trials was 0.60 (95% CI: 0.48 to 0.72) compared with trials without chemotherapy 0.08 (95% CI: 0.03 to 0.13). Conclusions: Although the risk of grade 5 toxicity is low, the risk of major toxicity is significant in phase I RT trials. These values are comparable to published risk estimates for phase I non-RT trials.

International Journal of Radiation Oncology*Biology*Physics, 2012

Purpose: To test the hypothesis that radiotherapy (RT) improves the outcome of patients with unre... more Purpose: To test the hypothesis that radiotherapy (RT) improves the outcome of patients with unresected, nonmetastatic bronchoalveolar carcinoma (BAC) by performing a populationbased analysis within the Surveillance, Epidemiology, and End Results (SEER) registry. Methods and Materials: Inclusion criteria were as follows: patients diagnosed with BAC, Stage IeIII, between 2001 and 2007. Exclusion criteria included unknown stage, unknown primary treatment modality, Stage IV disease, and those diagnosed at autopsy. Demographic data, treatment details, and overall survival were retrieved from the SEER database. Survival was analyzed using the Kaplan-Meier method and logerank test. Results: A total of 6933 patients with Stage IeIII BAC were included in the analysis. The median age at diagnosis was 70 years (range, 10e101 years). The majority of patients were diagnosed with Stage I (74.4%); 968 patients (14%) did not undergo surgical resection. Unresected patients were more likely to be older (p < 0.0001), male (p Z 0.001), black (p < 0.0001), and Stage III (p < 0.0001). Within the cohort of unresected patients, 300 (31%) were treated with RT. The estimated 2-year overall survival for patients with unresected, nonmetastatic BAC was 58%, 44%, and 27% in Stage I, II, and III, respectively. Factors associated with improved survival included female sex, earlier stage at diagnosis, and use of RT. Median survival in those not receiving RT vs. receiving RT was as follows: Stage I, 28 months vs. 33 months (n Z 364, p Z 0.06); Stage II, 18 months vs. not reached (n Z 31, nonsignificant); Stage III, 10 months vs. 17 months (n Z 517, p < 0.003). Conclusions: The use of RT is associated with improved prognosis in unresected Stage IeIII BAC. Less than a third of patients who could have potentially benefited from RT received it, suggesting that the medical specialists involved in the care of these patients underappreciate the importance of RT. Ó 2012 Elsevier Inc.

International Journal of Radiation Oncology*Biology*Physics, 2010

We have reviewed the published data regarding radiotherapy (RT)-induced brain injury. Radiation n... more We have reviewed the published data regarding radiotherapy (RT)-induced brain injury. Radiation necrosis appears a median of 1-2 years after RT; however, cognitive decline develops over many years. The incidence and severity is dose and volume dependent and can also be increased by chemotherapy, age, diabetes, and spatial factors. For fractionated RT with a fraction size of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2.5 Gy, an incidence of radiation necrosis of 5% and 10% is predicted to occur at a biologically effective dose of 120 Gy (range, 100-140) and 150 Gy (range, 140-170), respectively. For twice-daily fractionation, a steep increase in toxicity appears to occur when the biologically effective dose is &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;80 Gy. For large fraction sizes (&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=2.5 Gy), the incidence and severity of toxicity is unpredictable. For single fraction radiosurgery, a clear correlation has been demonstrated between the target size and the risk of adverse events. Substantial variation among different centers&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; reported outcomes have prevented us from making toxicity-risk predictions. Cognitive dysfunction in children is largely seen for whole brain doses of &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=18 Gy. No substantial evidence has shown that RT induces irreversible cognitive decline in adults within 4 years of RT.

International Journal of Radiation Oncology*Biology*Physics, 2011

Cancer, 2013

BACKGROUND: Over the past 2 decades, significant progress has been made in the field of metastati... more BACKGROUND: Over the past 2 decades, significant progress has been made in the field of metastatic colorectal cancer (mCRC) regarding new imaging techniques, surgical interventions, and systemic therapy. It is not known whether the benefit from these interventions has extended overall survival (OS) within the general mCRC population. A population-based survival analysis of newly diagnosed patients who presented with mCRC was therefore performed. METHODS: Survival statistics were extracted from the Surveillance, Epidemiology, and End Results (SEER) database for patients diagnosed with mCRC between 1988 and 2008. Demographic variables collected included age, race, and tumor grade. Survival was analyzed using the Kaplan-Meier method and extended Cox proportional hazard model as appropriate. RESULTS: The study population consisted of 42,347 patients diagnosed with mCRC between 1988 and 2008 (52% women; mean age, 67 years). The 1-and 2-year estimated OS rates were 44% and 22%, respectively. Prognostic variables included race, sex, age, tumor location, and year of diagnosis. Median OS improved from 8 months to 14 months between 1988 and 2008. Significant improvements in OS were seen for all disease sites, but especially for descending colon cancers. Whereas the median OS increased by 13 months in patients 50 years of age and by 7 months in patients 51-70 years of age, the median OS of patients >70 years of age increased by only 1 month between 1988 and 2008. CONCLUSIONS: There has been a continuous improvement in OS of patients diagnosed with mCRC between 1988 and 2008, especially for left-sided tumors. Little improvement has been seen in patients over 70 years of age. Cancer 2013;000:000-000.

Background: Treatment of high-grade glioma consists of fractionated radiation therapy (RT) ± chem... more Background: Treatment of high-grade glioma consists of fractionated radiation therapy (RT) ± chemotherapy. The incidence/significance of neurological toxicity (NT) in this disease is not known. We evaluated the relationship between acute and chronic NT, and ultimate outcome, as well as risk factors for NT from the RTOG database.American Society of Clinical Oncology (ASCO) 46th Annual Meeting June 4-8, Chicago, IL.