Deletion of Slc6a14 reduces cancer growth and metastatic spread and improves survival in KPC mouse model of spontaneous pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is lethal. There is a dire need for better therapeutic targets. Cancer cells have increased demand for sugars, amino acids, and lipids and therefore up-regulate various nutrient transporters to meet this demand. In PDAC, SLC6A14 (an amino acid transporter (AAT)) is up-regulated, affecting overall patient survival. Previously we have shown using in vitro cell culture models and in vivo xenograft mouse models that pharmacological inhibition of SLC6A14 with α-methyl-l-tryptophan (α-MLT) attenuates PDAC growth. Mechanistically, blockade of SLC6A14-mediated amino acid transport with α-MLT leads to amino acid deprivation, eventually inhibiting mTORC1 signaling pathway, in tumor cells. Here, we report on the effect of Slc6a14 deletion on various parameters of PDAC in KPC mice, a model for spontaneous PDAC. Pancreatic tumors in KPC mice show evidence of Slc6a14 up-regulation. Deletion of Slc6a14 in this mouse attenuates PDAC growth, decreases the metastatic spread of the tumor, reduces ascites fluid accumulation, and improves overall survival. At the molecular level, we show lower proliferation index and reduced desmoplastic reaction following Slc6a14 deletion. Furthermore, we find that deletion of Slc6a14 does not lead to compensatory up-regulation in any of the other amino transporters. In fact, some of the AATs are actually down-regulated in response to Slc6a14 deletion, most likely related to altered mTORC1 signaling. Taken together, these results underscore the positive role SLC6A14 plays in PDAC growth and metastasis. Therefore, SLC6A14 is a viable drug target for the treatment of PDAC and also for any other cancer that overexpresses this transporter.

α-Methyl-l-tryptophan as a weight-loss agent in multiple models of obesity in mice.

α-Methyl-L-tryptophan (α-MLT) is currently in use as a tracer in its 11C-labeled form to monitor the health of serotonergic neurons in humans. In the present study, we found this compound to function as an effective weight-loss agent at pharmacological doses in multiple models of obesity in mice. The drug was able to reduce the body weight when given orally in drinking water (1 mg/ml) in three different models of obesity: normal mice on high-fat diet, Slc6a14-null mice on high-fat diet, and ob/ob mice on normal diet. Only the l-enantiomer (α-MLT) was active while the d-enantiomer (α-MDT) had negligible activity. The weight-loss effect was freely reversible, with the weight gain resuming soon after the withdrawal of the drug. All three models of obesity were associated with hyperglycemia, insulin resistance, and hepatic steatosis; α-MLT reversed these features. There was a decrease in food intake in the treatment group. Mice on a high-fat diet showed decreased cholesterol and protein in the serum when treated with α-MLT; there was however no evidence of liver and kidney dysfunction. Plasma amino acid profile indicated a significant decrease in the levels of specific amino acids, including tryptophan; but the levels of arginine were increased. We conclude that α-MLT is an effective, reversible, and orally active drug for the treatment of obesity and metabolic syndrome.

SLC6A14 deficiency is linked to obesity, fatty liver, and metabolic syndrome but only under conditions of a high-fat diet.

SLC6A14 is a Na+/Cl--coupled transporter for neutral/cationic amino acids, expressed in ileum and colon. A single-nucleotide polymorphism (SNP), rs2011162 (-22,510C > G), in SLC6A14 coding for the 3'-untranslated region (3'-UTR) is associated with obesity in humans. But the impact of this polymorphism on the transporter expression and its connection to obesity are not known. Our objective was to address these issues. The impact of rs2011162 (-22,510C > G) on SLC6A14 expression was monitored using a luciferase reporter. The link between Slc6a14 and obesity was investigated in wild type and Slc6a14-/- mice when fed a normal diet or a high-fat diet. The obesity-associated 3'-UTR polymorphism reduced SLC6A14 expression. With a high-fat diet, Slc6a14-/- mice gained more weight than wild type mice. With normal diet, there was no difference between the two genotypes. The gain in body weight with the high-fat diet in Slc6a14-/- mice was accompanied with metabolic syndrome. With the high-fat diet, Slc6a14-/- mice showed increased food intake, developed fatty liver, and altered plasma amino acid profile. The high-fat diet-associated hepatic steatosis in Slc6a14-/- mice showed male preponderance. We conclude that the 3'-UTR SNP in SLC6A14 associated with obesity decreases the expression of SLC6A14 and that the deficiency of SLC6A14 is linked to obesity. This is supported by the findings that Slc6a14-/- mice develop obesity, fatty liver, and metabolic syndrome. This connection is evident only with a high-fat diet. Therefore, dietary/pharmacologic interventions that induce SLC6A14 expression in the intestinal tract might have potential for obesity prevention.1.

Hereditary hemochromatosis promotes colitis and colon cancer and causes bacterial dysbiosis in mice.

Hereditary hemochromatosis (HH), an iron-overload disease, is a prevalent genetic disorder. As excess iron causes a multitude of metabolic disturbances, we postulated that iron overload in HH disrupts colonic homeostasis and colon-microbiome interaction and exacerbates the development and progression of colonic inflammation and colon cancer. To test this hypothesis, we examined the progression and severity of colitis and colon cancer in a mouse model of HH (Hfe-/-), and evaluated the potential contributing factors. We found that experimentally induced colitis and colon cancer progressed more robustly in Hfe-/- mice than in wild-type mice. The underlying causes were multifactorial. Hfe-/- colons were leakier with lower proliferation capacity of crypt cells, which impaired wound healing and amplified inflammation-driven tissue injury. The host/microflora axis was also disrupted. Sequencing of fecal 16S RNA revealed profound changes in the colonic microbiome in Hfe-/- mice in favor of the pathogenic bacteria belonging to phyla Proteobacteria and TM7. There was an increased number of bacteria adhered onto the mucosal surface of the colonic epithelium in Hfe-/- mice than in wild-type mice. Furthermore, the expression of innate antimicrobial peptides, the first-line of defense against bacteria, was lower in Hfe-/- mouse colon than in wild-type mouse colon; the release of pro-inflammatory cytokines upon inflammatory stimuli was also greater in Hfe-/- mouse colon than in wild-type mouse colon. These data provide evidence that excess iron accumulation in colonic tissue as happens in HH promotes colitis and colon cancer, accompanied with bacterial dysbiosis and loss of function of the intestinal/colonic barrier.

Yellow-Gold Polarized Light Microscopy May Improve Accuracy of Pathological Staging of Colorectal Adenocarcinoma.

Introduction Polarized light (PL) has been used in pathology for multiple reasons, including the demonstration of foreign bodies, the evaluation of crystals, and the demonstration of fibrosis. We incidentally found that yellow-gold polarization routinely occurs surrounding desmoplastic scar tissue abutting the invasive glands of colonic adenocarcinoma. We hypothesized that evaluating the use of polarized light over a series of invasive adenocarcinomas of the large intestine might produce evidence of its utility. Methods Large intestinal resections with invasive adenocarcinoma were reviewed with yellow-gold polarized light microscopy by two surgical pathologists postoperatively between January 2017 and March 2019. Specimens were examined under yellow-gold polarized light to evaluate invasion from the submucosa into the muscularis propria, from the muscularis propria into pericolic fat, and to the serosa. The diagnosed location, T stage, history of radiotherapy, mucinous features, and grade were recorded. Photographs were taken when images were deemed to be of value. The two-tailed Fisher's exact test was used to compare the invasion detection of the tumor into fat in scar tissue in colorectal cancer. Results A total of 75 large intestinal resections with invasive adenocarcinoma from 75 patients were accessioned. Concerning the initial stage, three (4%) were T1, nine (12%) were T2, 46 (61%) were T3, and 17 (22%) were T4. A history of previous radiation treatment was seen in 10 (13%). Two (2%) were poorly differentiated. Nine (12%) were mucinous carcinomas; mucinous areas were seen to pose difficulty in 12 (16%). Overall, one out of nine, initially staged as T2, was upstaged to T3 (11%), with the addition of yellow-gold polarized light microscopy. One tumor was downstaged from T2 to T1 (11%). For many T2 and T3 tumors, invasion into the muscularis propria was better defined by yellow-gold polarized light. Conclusion Yellow-gold polarized light microscopy may be a useful adjunct to conventional microscopy in more precisely staged pathological colorectal cancer specimens.

Chronic exposure to excess iron promotes EMT and cancer via p53 loss in pancreatic cancer.

Based on the evidence that hemochromatosis, an iron-overload disease, drives hepatocellular carcinoma, we hypothesized that chronic exposure to excess iron, either due to genetic or environmental causes, predisposes an individual to cancer. Using pancreatic cancer as our primary focus, we employed cell culture studies to interrogate the connection between excess iron and cancer, and combined in vitro and in vivo studies to explore the connection further. Ferric ammonium citrate was used as an exogenous iron source. Chronic exposure to excess iron induced epithelial-mesenchymal transition (EMT) in normal and cancer cell lines, loss of p53, and suppression of p53 transcriptional activity evidenced from decreased expression of p53 target genes (p21, cyclin D1, Bax, SLC7A11). To further extrapolate our cell culture data, we generated EL-KrasG12D (EL-Kras) mouse (pancreatic neoplastic mouse model) expressing Hfe+/+ and Hfe-/- genetic background. p53 target gene expression decreased in EL-Kras/Hfe-/- mouse pancreas compared to EL-Kras/Hfe+/+ mouse pancreas. Interestingly, the incidence of acinar-to-ductal metaplasia and cystic pancreatic neoplasms (CPN) decreased in EL-Kras/Hfe-/- mice, but the CPNs that did develop were larger in these mice than in EL-Kras/Hfe+/+ mice. In conclusion, these in vitro and in vivo studies support a potential role for chronic exposure to excess iron as a promoter of more aggressive disease via p53 loss and SLC7A11 upregulation within pancreatic epithelial cells.

DFseq: Distribution-Free Method to Detect Differential Gene Expression for RNA-Sequencing Data.

Many current RNA-sequencing data analysis methods compare expressions one gene at a time, taking little consideration of the correlations among genes. In this study, we propose a method to convert such an one-dimensional comparison approach into a two-dimensional evaluation of the ratio of standard deviations (SD) of two constructed random variables. This method allows the identification of differentially expressed genes while controlling a preset significance level conditional on the read count mean-variance relationship. Meanwhile, correlations among genes are naturally accommodated due to the clustering of genes with similar distribution in the proposed σ-σ plot. The proposed distribution-free method is designated as DFseq, because it does not depend on a parametric distribution to fit read count. As a result, compared with parametric methods, DFseq can effectively handle genes with a bimodal-like distribution and/or genes with excessive 0 read counts, as well as genes with outlying observations. Besides, DFseq is an ideal platform for comparing performance of different differential gene expression detection methods.

Operative Management of T1b Gallbladder Carcinoma with Concurrent Hepatic Anastomosing Hemangioma.

We report a case of stage T1b gallbladder carcinoma with concurrent hepatic anastomosing hemangioma managed by operative resection. We review the work-up and surgical management of this patient. We also discuss the relevant literature of both gallbladder cancer and hepatic anastomosing hemangioma, a recently described and rare variant of capillary hemangioma.

Isolated Asymptomatic Metastatic Melanoma to the Colon: A Case Report.

Metastatic melanoma is generally rare, and the colon is a very rare metastatic site. We report a case of asymptomatic, isolated metastatic melanoma to the colon. Asymptomatic patients are usually not expected to have metastatic lesions in the colon. Ninety-five percent of large bowel metastases are identified during a postmortem examination. Our patient was found to have metastatic melanoma to the colon during a follow-up colonoscopy done for the surveillance of colon polyps. An awareness that patients with melanoma may possibly develop colon metastases is needed.

Novel Treatment of Melanoma: Combined Parasite-Derived Peptide GK-1 and Anti-Programmed Death Ligand 1 Therapy.

Recent successes in the development of new therapies for metastatic melanoma, such as mitogen-activated protein kinase pathway inhibitors, anticytotoxic T lymphocyte-associated antigen-4, and programmed cell death protein 1/programmed cell death ligand 1 (PD-L1) pathway-blocking antibodies, as well as combination strategies, all yielded promising results, changing the continually evolving landscape of therapeutic options for patients with melanoma. One promising new treatment modality is based on the use of immunomodulatory monoclonal antibodies that enhance the function of components of the antitumor immune response such as T cells or block immunologic checkpoints that restrain effective antitumor immunity. Program death-1 receptor and its ligand, PD-L1, is a major mechanism by which a tumor suppresses T cell-mediated antitumor immune responses. Studies in mice have shown that GK-1, an 18 amino acid peptide from Taenia crassiceps cisticerci, has the potential to be used as a primary or adjuvant component for the treatment of cancers by stimulating proinflammatory cytokines. The authors hypothesized that treatment with GK-1 in combination with anti-PD-L1 will increase survival in mice bearing melanoma tumors. C57BL/6 mice were injected with B16-F10-luc2 cells and separated into four groups: control, GK-1, anti-PD-L1, and GK-1/anti-PD-L1. The tumor sizes were measured and monitored using calipers and bioluminescence. The GK-1 peptide in combination with anti-PD-L1 showed significantly longer survival (34 days) compared with the other groups (23-27 days). This means an increase; survival increased 47.82% in the mice treated with GK-1+anti-PD-L1, 21.7% in mice treated with GK-1 alone, and 6.08% in those mice treated with anti-PD-L1 only. Blood samples were collected at days 0, 14, and at euthanization or end of the experiment and monitored for cytokines using mouse-specific V-PLEX Proinflammatory Panel. A decrease in TNF-α, IL-4, IL-5, IL-6, and IL-10 serum levels was observed in the GK-1/anti-PD-L1 combination group that may explain the beneficial effects of the combination treatment in prolonging the life of mice bearing melanoma. The data indicate that GK-1/anti-PD-L1 combined therapy affectively increases survival and warrants further clinical investigations.

Rare Occurrence of a Poorly Differentiated Neuroendocrine Tumor of the Bladder.

Neuroendocrine tumors rarely occur in the urinary bladder. They can be carcinomatous, subdivided into small cell and large cell pathology. Small cell carcinoma of the bladder is a rarity that may present at an advanced pathologic stage. No treatment regimens have been standardized for local or metastatic disease. Review of the recent literature shows equivalent survival data for localized disease treated with chemoradiotherapy combined with either bladder sparing surgery or radical cystectomy. Patients with significant comorbidities are an additional challenge. We report a case of poorly differentiated neuroendocrine tumor of the bladder, which could not be classified as small or large cell carcinoma, complicated by significant comorbidities. After management with transurethral resection of the tumor, adjuvant chemotherapy, and radiation, the patient is alive and asymptomatic nearly 1 year after initial TURBT with no evidence of disease recurrence.

The Peridural Membrane of the Human Spine is Well Innervated.

There is evidence that low back pain may originate from a peridural membrane (PDM) at the inferior and medial aspect of neural foramen of the lumbar spine. The objective of this investigation was to determine if this membrane contains neural elements suggestive of sensory innervation with nociceptive function. Spines of four embalmed and three non-embalmed human cadavers were dissected using a sagittal approach to the neural foramen. Seventeen samples of the peridural membrane overlying the neural foramen were collected for immunohistochemistry (IHC) examination by light microscopy and transmission electron microscopy (TEM). Chromagin tagged antibodies to protein gene product 9.5 (PGP9.5) and S-100, and fluorescent antibodies to substance P and calcitonin gene related peptide (CGRP) were used to label neural structures in tissue sections cut from paraffin embedded blocks. This approach allows good visualization of all neural elements, small sensory, and nociceptive nerve fibers in particular. Neural elements were found in all samples. Marked presence of small nerve fibers was observed in 12 of 15 samples. IHC and TEM evaluation revealed myelinated as well as unmyelinated fibers in the peridural membrane. CGRP and substance P immunoreactive fibers indicative of nociceptive function were abundant. These findings confirm and expand evidence that the peridural membrane in human is well innervated and contains sensory nociceptive nerve fibers suggestive of a nociceptive function of the membrane.

Countries with high circumcision prevalence have lower prostate cancer mortality.

The present study determined the relationship of male circumcision (MC) prevalence with prostatic carcinoma mortality rate in the 85 countries globally for which data on each were available. MC prevalence in different countries were obtained from a WHO report and allocated to WHO categories of 81%-100%, 20%-80%, and 0%-19%. Prostatic carcinoma mortality data were from Globoscan, gross national income per capita as well as male life expectancy were from a World Bank report, and percentages of Jews and Muslims by country were from the Pew Research Institute and the North American Jewish Data Bank. Negative binomial regression was used to estimate prostatic carcinoma mortality rate ratios. Compared to countries with 81%-100% MC prevalence, prostatic carcinoma mortality rate was higher in those with MC prevalence of 0%-19% (adjusted OR [adjOR] =1.82; 95% CI 1.14, 2.91) and 20%-80% (adjOR = 1.80; 95% CI, 1.16, 2.78). Higher Muslim percentage (adjOR = 0.92 [95% CI 0.87, 0.98] for each 10% increase) and longer life expectancy (adjOR = 0.82 [95% CI 0.72, 0.93] for each 5 additional years) were associated with lower prostatic carcinoma mortality. Higher gross national income per capita (adjOR = 1.10 [95% CI 1.01, 1.20] for double this parameter) correlated with higher mortality. Compared with American countries, prostatic carcinoma mortality rate was similar in Eastern Mediterranean countries (adjOR = 1.02; 95% CI 0.58, 1.76), but was lower in European (adjOR = 0.60; 95% CI 0.50, 0.74) and Western Pacific countries (adjOR = 0.54, 95% CI 0.37, 0.78). Thus, prostate cancer mortality is significantly lower in countries in which MC prevalence exceeds 80%.

Hormone Replacement Therapy, Likely Neither Angel Nor Demon.

PURPOSE: A decline in breast cancer incidence has been attributed to the reduction in hormone replacement therapy (HRT) prescriptions since the publication of the landmark WHIT paper in 2003. Concurrently, a relationship between HRT and cerebrovascular disease incidence has also been suggested. No generalized analysis of HRT prescription rates and breast cancer incidence rates that included more than seven years of data. We hypothesized that detailed analysis of SEER data would clarify the relationship between HRT use and breast cancer incidence. Given the large decline in HRT prescription rates uncovered, analyses of potential complications were also conducted, with the understanding that a small effect or one limited to a subpopulation, such as a single race, might not be detected. METHODS: Incidence rates (per 100,000 women) and standard errors for ductal and lobular breast carcinomas, and endometrioid /endometrial carcinomas in women over 50 years were obtained from the Surveillance, Epidemiology, and End Results (SEER) database 1992-2012. From the Medical Expenditure Panel Survey 1996-2012 weighted counts and standard errors of hormone replacement therapy (HRT) prescriptions for women over 50 years were obtained. Using the National Hospital Discharge Survey (NHDS), 1996-2010 weighted counts and standard errors of femoral neck fractures, total hip replacements, acute myocardial infarctions, and cerebral infarctions were obtained for 50+ year men and women. Weighted counts and standard errors were divided by US census figures and multiplied by 100,000. Joinpoint regression was used to analyze rates. MAIN RESULTS: Beginning 2001, HRT prescription rates dropped dramatically, 2001-2012 AAPC -14.9 (95% CI -17.4, -12.4). Breast cancer rates, which began to decline in 1999, increased after 2003; 2012 rates were similar to those seen in 2001 for both ductal, AAPC 0.1 (-0.4, 0.6) and lobular, AAPC 0.5 (-0.4, 1.5), carcinoma. Endometrial carcinoma rates increased, 2001-2012 AAPC 3.5 (3.1, 3.8), arguing against a negative effect of HRT discontinuation of endometrial carcinoma. Tests for parallelism failed to detect APC differences among genders for femoral neck fractures (P = 0.24), for total hip replacements (P = 0.11), for myocardial infarctions (P = 0.10), or for cerebral infarctions (P = 0.19), precluding any assignment of general effect on these disorders by HRT. CONCLUSIONS: Using SEER data, we demonstrated that changes in breast cancer rates cannot be explained by HRT prescription rate changes.

Implications on clinical management of the small renal mass in patients 80 years of age and older based on a retrospective review of the SEER database.

PURPOSE: Incidental detection of small renal masses has increased in recent years with increased use of various imaging modalities, and a substantial number of diagnoses are made in the elderly population. Minimally invasive surgical procedures have previously been established as options with excellent long-term oncological results, but surveillance strategies have more recently been introduced as alternatives for surgical intervention. This study reviews the outcomes for elderly patients treated with observation or surgery for small renal masses in order to better elucidate optimal management strategies. METHODS: A total of 4647 patients from the SEER database met criteria for inclusion in this study. Cumulative incidences of RCC-specific mortality and non-RCC-related mortality were estimated, and frequency distributions by tumor size and surgical status were calculated. RESULTS: No difference in RCC-related mortality was observed among all treatment groups, including surveillance, for tumors 1-30 mm in size. RCC-related mortality was significantly lower for surgically treated patients for all other tumor size groups. Mortality unrelated to RCC was significantly higher in patients undergoing surveillance compared to those undergoing surgical intervention for tumor sizes 1-30 or 1-40 mm. CONCLUSIONS: A small renal mass in patients of 80+ years of age is best defined as up to 3 cm in size. For these patients, observation appears be a valid, if not preferential strategy. Patients 80+ years of age with renal masses greater than 3 cm still appear to benefit from surgical intervention.

Treatment of Hepatic Epithelioid Hemangioendothelioma: Finding Uses for Thalidomide in a New Era of Medicine.

Hepatic epithelioid hemangioendothelioma (HEH) is extremely rare, occurring in 1 to 2 per 100,000, with chemotherapy options not well defined. Our case involved a 49-year-old female who had hepatic masses and metastasis to the lungs with a liver biopsy revealing HEH. After developing a rash from sorafenib, thalidomide was started with the progression of disease stabilized. Resection is only an option in 10% of the cases; therefore, chemotherapy is the only line of treatment. Newer chemotherapy alternatives are targeting angiogenesis via the vascular endothelial growth factor. Thalidomide was first used as an antiemetic, but, sadly, soon linked to phocomelia birth defects. Given the mechanism of action against angiogenesis, thalidomide has a valid role in vascular tumors. In conclusion, the use of thalidomide as chemotherapy is novel and promising, especially in the setting of a rare vascular liver tumor such as HEH.

Osteoclastic giant cell tumor of the pancreas.

INTRODUCTION: Pancreatic giant cell tumors are rare, with an incidence of less than 1% of all pancreatic tumors. Osteoclastic giant cell tumor (OGCT) of the pancreas is one of the three types of PGCT, which are now classified as undifferentiated carcinoma with osteoclast-like giant cells. PRESENTATION OF CASE: The patient is a 57 year old woman who presented with a 3 week history of epigastric pain and a palpable abdominal mass. Imaging studies revealed an 18cm×15cm soft tissue mass with cystic components which involved the pancreas, stomach and spleen. Exploratory laparotomy with distal pancreatectomy, partial gastrectomy and splenectomy was performed. Histology revealed undifferentiated pancreatic carcinoma with osteoclast-like giant cells with production of osteoid and glandular elements. DISCUSSION: OGCT of the pancreas resembles benign-appearing giant cell tumors of bone, and contain osteoclastic-like multinucleated cells and mononuclear cells. OGCTs display a less aggressive course with slow metastasis and lymph node spread compared to pancreatic adenocarcinoma. Due to the rarity of the cancer, there is a lack of prospective studies on treatment options. Surgical en-bloc resection is currently considered first line treatment. The role of adjuvant therapy with radiotherapy or chemotherapy has not been established. CONCLUSION: Pancreatic giant cell tumors are rare pancreatic neoplasms with unique clinical and pathological characteristics. Osteoclastic giant cell tumors are the most favorable sub-type. Surgical en bloc resection is the first line treatment. Long-term follow-up of patients with these tumors is essential to compile a body of literature to help guide treatment.

Odds of death after glioblastoma diagnosis in the United States by chemotherapeutic era.

Bevacizumab (BZM) and temozolomide (TMZ) have been shown to be beneficial in the treatment of patients with glioblastoma. We sought evidence for the benefit of BZM in the general patient population at large. The Surveillance, Epidemiology, and End Results SEER database was queried for patients diagnosed with glioblastoma between 2000 and 2009, divided into a pre-TMZ era (January 2000-June 2003), a transitional era (July 2003-March 2005), a TMZ era (April 2005-October 2007), and a BZM-TMZ era (November 2007-December 2009). Binomial logit regression analyzed odds of death, taking into account age at diagnosis, tumor size, gender, race, marital status, radiotherapy, and extensive surgery. Compared with the pre-TMZ era, odds of death were decreased in the TMZ era by 12% (97.5% CI [confidence interval] 3-20%) 6 months after diagnosis and 36% (30-42%) a year after diagnosis; corresponding values for BZM-TMZ were 31% (24-37%) and 50% (45-55%). For era comparisons, decreases in odds of death were larger at 12 than 6 months; the opposite was true for extensive surgery and radiotherapy (P < 0.025, Wald χ(2) test, for each analysis). For both 6 and 12 month comparisons, odds of death in the BZM-TMZ era were lower than in the TMZ era (P < 0.025, Wald χ(2) test, for each analysis). The results provide evidence that TMZ positively impacted survival of glioblastoma patients and that the addition of BZM further improved survival, this lends support to the addition of BZM to the chemotherapeutic armamentarium. Evaluation of odds of death is an attractive alternative to Cox regression when proportional hazards assumptions are violated and follow-up is good.