Racial disparities in rates of invasiveness of resected intraductal papillary mucinous neoplasms in the United States

BACKGROUND

Racial and ethnic disparities have been observed in the multidisciplinary management of pancreatic ductal adenocarcinoma. Intraductal papillary mucinous neoplasm is the most common identifiable precursor to pancreatic ductal adenocarcinoma, where early surgical intervention before the development of an invasive intraductal papillary mucinous neoplasm improves survival. The association of race/ethnicity with the risk of identifying invasive intraductal papillary mucinous neoplasms during resection has not been previously defined.

METHODS

The American College of Surgeons National Quality Improvement Program targeted pancreatectomy database (2014-2021) was queried for patients with race/ethnicity data who underwent resection of an intraductal papillary mucinous neoplasm. Backward Wald logistic regression modeling (P ≤ 0.05 for entry; P > .10 for removal) was used to identify independent predictors of invasion.

RESULTS

A total of 4,505 cases of resected intraductal papillary mucinous neoplasms were identified, with 923 (20.5%) demonstrating invasive intraductal papillary mucinous neoplasms. The cohort of individuals other than non-Hispanic Whites were significantly more likely to have invasive intraductal papillary mucinous neoplasms (White, 19.9%; Black, 24.2%; Asian, 23.7%; Hispanic, 22.6%; P = .026). Such disparity could not be explained by greater comorbidity, as non-White patients were significantly younger (age <65 years: 41.7% vs 33.2%, P < .001) and had better physical status (American Society of Anesthesiologists score ≤2: 28.8% vs 25.2%, P = .053). After controlling for clinicodemographic variables, being an individual of race/ethnicity other than White was independently associated with higher odds of invasive intraductal papillary mucinous neoplasms (odds ratio, 1.280; 95% confidence interval, 1.046-1.566; P = .017). No differences in postoperative morbidity were observed.

CONCLUSION

In a national cohort of patients with resected intraductal papillary mucinous neoplasms, individuals who identified as being of race/ethnicity other than White were significantly more likely to have invasive intraductal papillary mucinous neoplasms during surgical resection.

Unplanned Hospitalization and Subsequent Mortality in Lung Cancer Patients Undergoing Concomitant Chemo-/Immuno-Therapy and Radiotherapy: An Analysis of Over 10,000 Patients in a Nationwide Database

PURPOSE/OBJECTIVE(S)

Radiotherapy (RT) and concomitant chemotherapy (CHT) is a major modality for treating many malignancies including lung cancer and is associated with toxicity-related unplanned hospitalization (UPH). Previous investigations of factors associated with UPH have been single institutional retrospective studies and none assessed the role of concurrent immunotherapy (IO). Here, we aimed to identify factors associated with UPH and in-hospital mortality by leveraging a multi-institutional nationwide database.

MATERIALS/METHODS

The Vizient® Clinical Data Base which includes data from 98% of the AAMC hospitals and 110 cancer hospitals, was queried for lung cancer patients (any histology) treated in 2019-2021 with RT+CHT/IO. Endpoints were UPH and mortality during or within 30 days of completion of RT. The variables included age, sex, race, ethnicity, income level (quartile), an education level (quartile), any concomitant CHT or IO drugs, RT technique (3D vs. IMRT vs. SBRT), obesity, prior hospitalization within 3 months, prior oncologic surgery within 3 months, prior CHT and/or IO within 3 months, insurance types, hospital types (Rural vs. Urban, AAMC vs. non-AAMC, NCCN vs. non-NCCN, bed size tertile). Logistic regression was performed to identify variables associated with UPH and in-hospital mortality. Data from the Vizient Clinical Data Base used with permission of Vizient, Inc. All rights reserved.

RESULTS

A total of 10,337 patients were included. The rate of UPH and mortality among UPH was 24.5% and 3.2%, respectively. Factors associated with UPH included other races (vs. White, OR 1.44; 95% CI 1.11-1.88; p<0.001), living in a low income zip code (OR 1.7; 95% CI 1.39-2.09; p = 0.0006), living in a zip code with lower education attainment (OR 0.71; 95% CI 0.58-0.86; p = 0.0007), CHT/IO types (cis-etoposide vs. carbo-Taxol, OR 1.33; 95% CI 1.13-1.57; p<0.0001), obesity (OR 1.71; 95% CI 1.53-1.92; p<0.0001), prior hospitalization (OR 2.0; 95% CI 1.80-2.22; p<0.0001), prior oncologic surgery (OR 0.34; 95% CI 0.22-0.52; p<0.0001), other primary payers (vs. commercial; OR 1.75; 95% CI 1.37-2.23; p<0.0001), rural hospital (OR 1.3; 95% CI 1.07-1.62, p<0.01), small bed size (OR 0.59; 95% CI 0.5-0.71; p<0.0001). Factors associated with in-hospital mortality included CHT/IO type (p<0.0001, but cis-etoposide vs. carbo-taxol no difference), prior hospitalization (OR 0.34; 95% CI 0.2-0.56; p<0.0001), AAMC (OR 2.12; 95% CI 1.23-3.67; p = 0.007), bed size (OR 0.58; 95% CI 0.38-0.88; p<0.01).

CONCLUSION

In the largest study to date regarding UPH and in-hospital mortality related to lung RT, we identified factors contributing to these endpoints. Future prospective studies are warranted to develop strategies to prevent these complications in high-risk populations.

HCRN GI16-288: A phase II trial of perioperative CV301 vaccination in combination with nivolumab and systemic chemotherapy for resectable hepatic-limited metastatic colorectal cancer—Preliminary efficacy and correlative results

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Background: Novel strategies to improve the efficacy of immune checkpoint inhibitors in microsatellite stable (MSS) mCRC are needed. CV301 is a vector-based vaccine that expresses carcinoembryonic antigen (CEA) and mucin 1 (MUC1), and in a phase II study in resected hepatic limited mCRC significantly improved OS compared with unvaccinated contemporary controls. Methods: In this multi-center randomized phase II study, patients with previously untreated resectable hepatic-limited mCRC were randomized to perioperative nivolumab + mFOLFOX +/- CV301 (Arm B) with a primary endpoint of 3-year OS. Treatment included mFOLFOX-nivo (+/- CV) x 4 cycles followed by resection, then 8 more cycles of mFOLFOX-nivo followed by maintenance nivo monthly for two years in both arms, and CV boosters concurrently with mFOLFOX, and then every 3 months for two years in arm B. Secondary endpoints of ORR (following induction pre-resection), PRR, and safety were determined. Correlative analyses included immune cell quantification using Immunoscore and T-cell clonality. Results: 17 patients were enrolled prior to premature closure for slow accrual (8 arm A, 9 arm B). At the time of data cutoff, 5 patients remained on treatment and no deaths had occurred. One patient was removed from study due to protocol non-compliance. The median age was 61, majority were male (59% vs 41%), and ECOG PS 0-1 (71% 0, 17% 1). All patients had complete surgical resection. Four patients (24%) experienced a SAE related to drug. The TRAE rate was 40.3%,. No AEs delayed/prevented surgical resection. The ORR in arm A was 50% (including 4 CR) and 87.5% in arm B (including 7 CR) (p=0.129, NS). There was no significant difference in pathologic response (p=0.9047). Correlative analyses demonstrated the Immunoscore CD3/CD8 predicted response to mFOLFOX + nivolumab, but did not correlate with response to CV301, though CV301 may induce a shift to predominantly cytotoxic CD8+ T cells. While there was no significant difference in T cell repertoire, clonality, fraction (TCFr) or richness, patients in arm B had significant decreases in blood TCFr and increase in tumor TCFr with treatment; those with CR had higher TCFr and clonality. Conclusions: The addition of CV301 to perioperative nivolumab and mFOLFOX was safe, did not delay or prevent surgical resection, and gave a higher response (p=ns due to sample size). Changes in T cells suggest a vaccine response. Clinical trial information: NCT03547999 . [Table: see text]

High-risk MSI-H stage II colon cancer: Treatment patterns and outcomes

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Background: For resected stage II MSI-high (MSI-H) colorectal cancer (CRC) without high-risk features (HRF), standard of care recommendation per NCCN guidelines is observation. For tumors with HRF, the prognostic significance and impact of adjuvant therapy remains uncertain. The NCDB was queried to assess outcomes. Methods: Adult patients with stage II MSI-H CRC, surgically resected between 2010 and 2017, were identified in the NCDB. Univariate and multivariate Cox proportional hazards models and Kaplan Meier survival curves were generated to assess impact of HRF, clinical and demographic variables, and chemotherapy use on overall survival (OS). Results: 9634 patients with stage II MSI-H CRC who met criteria were identified. In multivariate analysis T4 tumor status, < 12 lymph nodes (LN) examined, perineural invasion (PNI) and positive margins were associated with worse OS, as were older age and increased comorbidity index (CDCC). Poor differentiation and lymphovascular invasion (LVI) were not associated with OS. No OS difference was observed between T4a vs T4b tumors or based upon tumor sidedness, tumor size, or sex. Excluding poor differentiation (33%) and LVI (17%), HRFs were present in 26% of cases: 21% (n = 2033) had 1 HRF and 5% (n = 505) had > 1 HRF. HRFs were associated with decreased 5-year OS. For 1 HRF OS was 66% (HR 1.48, p < 0.0001) and for > 1 HRF OS was 54% (HR 2.31, p < .0001), compared to 77% with 0 HRFs. HRF presence was associated with increased chemotherapy use: 46% for > 1 HRF, 26% for 1 HRF, and 8% with 0 HRFs. pT4 tumors (T4b > T4a) and younger age were also associated with increased chemotherapy use. By age group, chemotherapy was utilized in 31% of those < 50, 27% of those 51-60, 17% of those 61-70 and 6% of those > 70 years old. In the overall population, chemotherapy administration was associated with improved OS on multivariate analysis compared with no treatment (N = 1344; HR 0.76, p < 0.0001). 69% of patients received multi-agent chemotherapy. However, survival was similar between those receiving single-agent vs multi-agent chemotherapy (HR 1.2, p = 0.2016). In patients < 60 years old, chemotherapy use was associated with decreased OS (HR 1.4, p = 0.0156). Conclusions: In this retrospective, uncontrolled large database survey, HRFs are associated with decreased OS in stage II MSI-H CRC. This data indicates that poor differentiation and LVI do not independently worsen outcomes, but that the presence of multiple HRFs bears relevance. Though chemotherapy was associated with improved OS, the association is reversed in the < 60 year old population; this analysis cannot fully control for extent of disease and PS, among other factors. Chemotherapy should be judiciously administered in Stage II MSI-H CRC with HRFs. Immunotherapy trials are justified.[Table: see text]

A Method to Estimate the Distribution of Proteins across Multiple Compartments Using Data from Quantitative Proteomics Subcellular Fractionation Experiments

Knowledge of cellular location is key to understanding the biological function of proteins. One commonly used large-scale method to assign cellular locations is subcellular fractionation, followed by quantitative mass spectrometry to identify proteins and estimate their relative distribution among centrifugation fractions. In most of such subcellular proteomics studies, each protein is assigned to a single cellular location by comparing its distribution to those of a set of single-compartment reference proteins. However, in many cases, proteins reside in multiple compartments. To accurately determine the localization of such proteins, we previously introduced constrained proportional assignment (CPA), a method that assigns each protein a fractional residence over all reference compartments (Jadot Mol. Cell Proteomics 2017, 16(2), 194-212. 10.1074/mcp.M116.064527). In this Article, we describe the principles underlying CPA, as well as data transformations to improve accuracy of assignment of proteins and protein isoforms, and a suite of R-based programs to implement CPA and related procedures for analysis of subcellular proteomics data. We include a demonstration data set that used isobaric-labeling mass spectrometry to analyze rat liver fractions. In addition, we describe how these programs can be readily modified by users to accommodate a wide variety of experimental designs and methods for protein quantitation.

PRMT5 Interacting Partners and Substrates in Oligodendrocyte Lineage Cells

The protein arginine methyl transferase PRMT5 is an enzyme expressed in oligodendrocyte lineage cells and responsible for the symmetric methylation of arginine residues on histone tails. Previous work from our laboratory identified PRMT5 as critical for myelination, due to its transcriptional regulation of genes involved in survival and early stages of differentiation. However, besides its nuclear localization, PRMT5 is found at high levels in the cytoplasm of several cell types, including oligodendrocyte progenitor cells (OPCs) and yet, its interacting partners in this lineage, remain elusive. By using mass spectrometry on protein eluates from extracts generated from primary oligodendrocyte lineage cells and immunoprecipitated with PRMT5 antibodies, we identified 1196 proteins as PRMT5 interacting partners. These proteins were related to molecular functions such as RNA binding, ribosomal structure, cadherin and actin binding, nucleotide and protein binding, and GTP and GTPase activity. We then investigated PRMT5 substrates using iTRAQ-based proteomics on cytosolic and nuclear protein extracts from CRISPR-PRMT5 knockdown immortalized oligodendrocyte progenitors compared to CRISPR-EGFP controls. This analysis identified a similar number of peptides in the two subcellular fractions and a total number of 57 proteins with statistically decreased symmetric methylation of arginine residues in the CRISPR-PRMT5 knockdown compared to control. Several PRMT5 substrates were in common with cancer cell lines and related to RNA processing, splicing and transcription. In addition, we detected ten oligodendrocyte lineage specific substrates, corresponding to proteins with high expression levels in neural tissue. They included: PRC2C, a proline-rich protein involved in methyl-RNA binding, HNRPD an RNA binding protein involved in regulation of RNA stability, nuclear proteins involved in transcription and other proteins related to migration and actin cytoskeleton. Together, these results highlight a cell-specific role of PRMT5 in OPC in regulating several other cellular processes, besides RNA splicing and metabolism.

BTCRC-GI20-457: A phase II study of atezolizumab and bevacizumab in Child-Pugh B7 hepatocellular carcinoma (the AB7 Trial)

TPS493

Background: Both the incidence and death rate of hepatocellular carcinoma (HCC) are on the rise in the United States, and overall, the prognosis is grim. First-line treatment options for patients with advanced disease previously included tyrosine kinase inhibitors (TKIs) which have resulted in a median overall survival (OS) of less than a year. Combinations of immune checkpoint inhibitors (CPIs) with vascular endothelial growth factor (VEGFR) inhibitors are of interest given the known effects of VEGF in the tumor microenvironment, including promoting inhibitory immune cells, suppressing maturation of dendritic cells, decreasing cytotoxic T cell responses, and altering lymphocyte development and trafficking. The phase III IMbrave150 trial investigated the combination of atezolizumab (A) and bevacizumab (B) as compared to sorafenib (S) in previously untreated locally advanced or metastatic HCC patients, and resulted in significantly improved OS (mOS: 19.2 mos AB vs 13.4 mos S), PFS (mPFS: 6.9 mos AB vs 4.3 mos S), and response rates (ORR: 29.8% AB vs 11.3% S), and a meaningful improvement in duration of response (mDOR: 18.1 mos AB vs 14.9 mos S). Notably, patients with class Child-Pugh B liver dysfunction were excluded from this study, although they are clinically abundant. We hypothesize the combination of AB will be safe and well tolerated in patients with locally advanced or metastatic HCC with Child-Pugh class B7 liver dysfunction. In addition, we expect efficacy will be similar to that demonstrated by the IMbrave150 study, and that ctDNA will correlate with, and possibly predict, clinical outcomes. Methods: This will be a single arm phase II study investigating the safety of the combination of AB in patients with previously untreated locally advanced or metastatic HCC with Child-Pugh B7 liver dysfunction. Patients must also be ECOG PS 0-1 and without clinically significant ascites or hepatic encephalopathy, untreated esophageal/gastric varices (assessed by EGD within the prior 6 months), or recent significant bleeding. We will enroll 50 patients with the primary endpoint of grade 3-5 treatment-related adverse event rate by CTCAE v5. Secondary endpoints include ORR, disease control rate (DCR), DOR, progression free survival (PFS), and OS. Correlative studies include tumor molecular signature by next generation sequencing (NGS) tissue analysis and ctDNA levels to correlate both with each other and with clinical benefit. Patients will receive A 1,200 mg IV and B 15 mg/kg IV every 3 weeks until disease progression or intolerable toxicity. Tumor imaging reassessment will occur every 3 cycles. Archival or fresh tumor biopsy will be required at baseline, and plasma for ctDNA will be collected with each imaging reassessment. The trial is being conducted at sites throughout the Big Ten Cancer Research Consortium (Big Ten CRC) and is currently screening eligible subjects (NCT04829383). Clinical trial information: NCT04829383.

Preoperative pembrolizumab for MSI high, EBV positive or PD-L1 positive locally advanced gastric cancer followed by surgery and adjuvant chemoradiation with pembrolizumab: Interim results of a phase 2 multi-center trial (NCT03257163)

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Background: Despite advances in therapy, outcomes of patients with gastric cancer in the US remain poor. Recent data demonstrated that certain subtypes of gastric cancer are less responsive to perioperative chemotherapy. Preliminary data suggest that patients with microsatellite unstable tumors (MSI-H), EBV expressing tumors, and tumors with high PD-L1 expression may benefit from immunotherapy. We initiated a clinical trial to evaluate the benefit of PD-1 checkpoint immunotherapy in this subset of patients with resectable gastric cancer. Methods: Interim analysis performed on this phase 2 multi-institutional clinical trial (NCT03257163) is presented. Patients with clinically staged T2-T4, N0-N3, M0 gastric adenocarcinoma are evaluated for loss of mismatch repair proteins, expression of EBV or PDL1 expression with CPS > 1%. Consented patients receive 2 cycles of neoadjuvant pembolizumab followed by surgical resection. Following surgery, patients receive adjuvant chemoradiation (45 Gy) with 5 cycles of capecitabine and concurrent pembrolizumab, followed by up to 1 year of pembrolizumab. The primary endpoint is disease-free survival. Results: Of the 15 patients currently enrolled (planned enrollment = 40), 6 patients were MSI-H, 2 EBV (+), and 7 had PDL1 expression with CPS > 1%. Two patients did not undergo surgical resection as 1 patient was found to have peritoneal disease at time of exploration and second was deemed too frail to proceed with surgery. In the 13 patients who underwent surgical resection, all are alive without evidence of recurrent disease (follow up 1 month – 22 months). After 2 cycles of pembrolizumab, 2 patients with MSI-H tumors had pathologic complete response. Clinical T stage was downstaged in 5 patients and clinical N stage was downstaged in 2 patients. PD-1 checkpoint immunotherapy was well tolerated with minimal need for dose reduction and limited toxicity. Conclusions: Early results from our phase 2 clinical trial show immunotherapy to be well tolerated with limited toxicity. Following 2 cycles of pembrolizumab, 2 patients with MSI-H had complete pathologic response and above a third of our patients were downstaged. No recurrences have been observed in the short-term follow-up of surgically resected patients. Clinical trial information: NCT03257163.

Evaluating clinical responses to BRAF inhibition in BRAF/TERT promoter mutated melanoma

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Background: Combined BRAF/MEK inhibition results in improved progression free and overall survival in BRAF mutated melanoma, but significant response is not universally observed. TERT promoter activating mutations often co-occur with BRAF mutations and have been associated with aggressive features and poorer prognosis. The TERT promotor inhibits apoptosis via a mechanism dependent upon BRAF mutant MAPK activation. Preclinical data in mouse models suggests that BRAF/TERT genetic duet melanomas are associated with improved response to BRAF/MEK inhibition as compared with BRAF mutant/TERT-WT melanomas. Methods: We performed a single center retrospective analysis of adults with melanoma with confirmed BRAF mutations +/- TERT promoter mutations. Responses and progression free survival in response to BRAF/MEK inhibition was assessed. Differences in RR and PFS were compared using Kaplan-Meier and Log-Rank. Results: 52 cases of BRAF/TERT genetic duet and BRAF mutated/TERT-WT melanomas were assessed. A total of 24 patients received BRAF/MEK inhibitors over the course of treatment meeting criteria for study inclusion; 9 (37.5%) BRAF/TERT genetic duet and 15 (62.5%) BRAF mutated/TERT-WT. BRAF V600E was present in 19/24 (79.2%) and V600K in 5/24 (20.8%). In the genetic duets, TERT -146C > T was present in 4/9 (44.4%), -124C > T in 2/9 (22.2%), -139_-138CC > TT in 2/9 (22.2%), and a SNV in 1/9 (11.1%). Mean age at diagnosis was 56 ± 13.5 years and 62.5% were male. ECOG PFS was 0-1 in 15/24 (62.5%), 2-3 in 6/24 (25%), and unreported in 3/24 (12.5%). Mean LDH at start of therapy was 391 (range 81-1664). At initial diagnosis 20.8% were Stage I, 25% Stage II, 37.5% Stage III, and 16.7% Stage IV. Two or more sites of disease were present in 10/24 (41.7%) and 2/24 (8.3%) had CNS metastases. BRAF/MEK directed therapy was first line in 6/24 (25%) of patients, others received prior immunotherapy. No significant differences between groups were observed in baseline demographics, disease state at diagnosis, or treatment history. In BRAF/TERT genetic duet melanomas CR was observed in 1/9 (11.1%), PR in 7/9 (77.8%), and NR in 1/9 (11.1%). In BRAF mutated/TERT-WT CR was observed in 3/15 (20%), PR in 11/15 (73.3%), and NR in 1/15 (6.7%). BRAF/TERT genetic duets were observed to initially have somewhat better PFS on first exposure to BRAF/MEK directed therapy but the PFS curves crossed at about 5 months with no significant difference observed overall (p = 0.40). Conclusions: This study is the first to report on outcomes of BRAF/MEK directed therapy in BRAF/TERT genetic duet vs BRAF mutated/TERT-WT melanomas in humans. While preclinical data from mouse models observed an improved response to BRAF/MEK inhibition in genetic duet tumors, no significant difference was observed. Our study is limited by small sample size. A multicenter analysis may be of interest to better understand the effects of BRAF inhibition in patients with BRAF/TERT genetic duet melanoma.

Evaluation of a Gene Expression Profiling Assay in Primary Cutaneous Melanoma

BACKGROUND

A significant proportion of deaths from cutaneous melanoma occur among patients with an initial diagnosis of stage 1 or 2 disease. The Decision-Dx Melanoma (DDM) 31-gene assay attempts to stratify these patients by risk of recurrence. This study aimed to evaluate this assay in a large single-institution series.

METHODS

A retrospective chart review of all patients who underwent surgery for melanoma at a large academic cancer center with DDM results was performed. Patient demographics, tumor pathologic characteristics, sentinel node status, gene expression profile (GEP) class, and recurrence-free survival (RFS) were reviewed. The primary outcomes were recurrence of melanoma and distant metastatic recurrence.

RESULTS

Data from 361 patients were analyzed. The median follow-up period was 15 months. Sentinel node biopsy was performed for 75.9% (n = 274) of the patients, 53 (19.4%) of whom tested positive. Overall, 13.6% (n = 49) of the patients had recurrence, and 8% (n = 29) had distant metastatic recurrence. The 3- and 5-year RFS rates were respectively 85% and 75% for the class 1A group, 74% and 47% for the class 1B/class 2A group, and 54% and 45% for the class 2B group. Increased Breslow thickness, ulceration, mitoses, sentinel node biopsy positivity, and GEP class 2B status were significantly associated with RFS and distant metastasis-free survival (DMFS) in the univariate analysis (all p < 0.05). In the multivariate analysis, only Breslow thickness and ulceration were associated with RFS (p < 0.003), and only Breslow thickness was associated with DMFS (p < 0.001).

CONCLUSION

Genetic profiling of cutaneous melanoma can assist in predicting recurrence and help determine the need for close surveillance. However, traditional pathologic factors remain the strongest independent predictors of recurrence risk.

Neoadjuvant therapy is associated with lower margin positivity rates after Pancreaticoduodenectomy in T1 and T2 pancreatic head cancers: An analysis of the National Cancer Database

BACKGROUND

Neoadjuvant therapy (NAT) for T1/T2 pancreatic adenocarcinoma (PDAC) prior to pancreaticoduodenectomy remains controversial. We compared positive margin rates in patients with clinical T1&T2 tumors who did and did not receive NAT.

METHODS

The National Cancer Database (NCDB) found clinical T1&T2 PDAC patients who underwent pancreaticoduodenectomy from 2004 to 2014. Univariate and multivariate regression determined factors associated with a positive margin and survival.

RESULTS

9795 patients underwent surgery for clinical T1 or T2 pancreatic head adenocarcinoma. 8472 patients had data regarding use of neoadjuvant and adjuvant therapies; of which, 774 (9.1%) received NAT and 435 (5.1%) received both chemotherapy and radiation therapy. NAT was found to lower positive margin rates from 21.8 to 15.5% (p < 0.0001) and when radiation was added this rate dropped to 13.4%. Positive margins were associated with worse overall survival (14.9 vs. 23.9 months; HR 1.702, p < 0.0001).

CONCLUSIONS

NAT is associated with a reduced positive margin rate in patients with T1 and T2 tumors. These findings support ongoing and future clinical trials of NAT in T1 and T2, early stage PDAC to determine impacts on survival.

Subcategorizing T1 Staging in Pancreatic Adenocarcinoma Predicts Survival in Patients Undergoing Resection: An Analysis of the National Cancer Database

Purpose: According to the American Joint Committee on Cancer (AJCC) 7th edition, T1 staging of pancreatic adenocarcinoma (PC) is defined as tumor limited to the pancreas, ≤2 cm. The AJCC 8th edition subcategorizes T1 staging into T1a (≤5 mm), T1b (≤1 cm), and T1c (≤2 cm) for PC despite the absence of supporting evidence. We sought to determine whether this new subcategorization has prognostic significance. Methods: A retrospective review of patients undergoing definitive surgery for PC was performed by using the National Cancer Database (NCDB) from 2004 to 2014. Kaplan-Meier survival was computed for the subcategories. Multivariable analysis (MVA) was performed by using stepwise regression. Results: The NCDB captured 41,552 stages I and II patients who underwent definitive surgery for PC in this 10-year period. A total of 2090 of these patients were pathological T1N0. The 5-year overall survival (OS) for patients with T1a (n = 319), T1b (n = 296), and T1c (n = 1309) PC was 68.8%, 57%, and 46.6%, respectively. This subcategorization lost significance on MVA and when focused on T1N1-2 patients. Recategorizing T stage into T1a (≤1 cm) and T1b (≤2 cm) resulted in statistical significance on MVA. Conclusion: Subcategorization of the T1 stage into T1a, T1b, and T1c in resected PC does differentiate OS in patients with node-negative disease. We support the AJCC 8th edition T1 stage subcategorization, while understanding that it does not differentiate OS on MVA. When this is further subcategorized into T1a (≤1 cm) and T1b (≤2 cm), it predicts OS in resected, node-negative patients on MVA.

5-Year Update of a Multi-Institution, Prospective Phase 2 Hypofractionated Postmastectomy Radiation Therapy Trial

PURPOSE

Hypofractionation in the setting of postmastectomy radiation (PMRT) is not currently the standard of care in most countries. Here we present a 5-year update of our multi-institutional, phase 2 prospective trial evaluating a novel 15-day hypofractionated PMRT regimen.

METHODS AND MATERIALS

Patients were enrolled to receive 3.33 Gy daily to the chest wall (or reconstructed breast) and regional lymphatics in 11 fractions with an optional 4-fraction mastectomy scar boost. The primary endpoint was freedom from grade 3 or higher late non-reconstruction-related radiation toxicities. Toxicities were scored using Common Terminology Criteria for Adverse Events v4.0. Secondary endpoints included local and locoregional recurrence rates, cosmesis, and reconstruction complications.

RESULTS

After enrolling 69 patients with stage II-IIIa breast cancer, 67 women were eligible for analysis. At a median follow up of 54 months, there were no acute or late grade 3 and 4 nonreconstruction reported toxicities. The grade 2 or greater late toxicity rate was only 12% and comprised grade 2 pain, fatigue, and lymphedema that persisted beyond 6 months after completion of radiation therapy. Only 3 women (4.6%) experienced a chest wall or nodal recurrence as a first site of relapse. Freedom from local failure, including local failure after distant relapse, was 92% at 5 years, and the 5-year overall survival was 90%.

CONCLUSIONS

This is the first prospective trial conducted in the United States to demonstrate the safe and effective use of hypofractionated PMRT. We have demonstrated a low complication rate while achieving excellent local control. Toxicity was better than anticipated based on previously published series of PMRT toxicities. Although our fractionation was novel, the radiobiological equivalent dose is similar to other hypofractionation schedules. This trial was the basis for the creation of Alliance A221505 (RT CHARM), which is currently accruing patients in a phase 3 randomized design.

Comparative Analysis of Quantitative Mass Spectrometric Methods for Subcellular Proteomics

Knowledge of intracellular location can provide important insights into the function of proteins and their respective organelles, and there is interest in combining classical subcellular fractionation with quantitative mass spectrometry to create global cellular maps. To evaluate mass spectrometric approaches specifically for this application, we analyzed rat liver differential centrifugation and Nycodenz density gradient subcellular fractions by tandem mass tag (TMT) isobaric labeling with reporter ion measurement at the MS2 and MS3 level and with two different label-free peak integration approaches, MS1 and data independent acquisition (DIA). TMT-MS2 provided the greatest proteome coverage, but ratio compression from contaminating background ions resulted in a narrower accurate dynamic range compared to TMT-MS3, MS1, and DIA, which were similar. Using a protein clustering approach to evaluate data quality by assignment of reference proteins to their correct compartments, all methods performed well, with isobaric labeling approaches providing the highest quality localization. Finally, TMT-MS2 gave the lowest percentage of missing quantifiable data when analyzing orthogonal fractionation methods containing overlapping proteomes. In summary, despite inaccuracies resulting from ratio compression, data obtained by TMT-MS2 assigned protein localization as well as other methods but achieved the highest proteome coverage with the lowest proportion of missing values.

Analysis of Brain and Cerebrospinal Fluid from Mouse Models of the Three Major Forms of Neuronal Ceroid Lipofuscinosis Reveals Changes in the Lysosomal Proteome

Treatments are emerging for the neuronal ceroid lipofuscinoses (NCLs), a group of similar but genetically distinct lysosomal storage diseases. Clinical ratings scales measure long-term disease progression and response to treatment but clinically useful biomarkers have yet to be identified in these diseases. We have conducted proteomic analyses of brain and cerebrospinal fluid (CSF) from mouse models of the most frequently diagnosed NCL diseases: CLN1 (infantile NCL), CLN2 (classical late infantile NCL) and CLN3 (juvenile NCL). Samples were obtained at different stages of disease progression and proteins quantified using isobaric labeling. In total, 8303 and 4905 proteins were identified from brain and CSF, respectively. We also conduced label-free analyses of brain proteins that contained the mannose 6-phosphate lysosomal targeting modification. In general, we detect few changes at presymptomatic timepoints but later in disease, we detect multiple proteins whose expression is significantly altered in both brain and CSF of CLN1 and CLN2 animals. Many of these proteins are lysosomal in origin or are markers of neuroinflammation, potentially providing clues to underlying pathogenesis and providing promising candidates for further validation.

Comparative effectiveness of radical prostatectomy with adjuvant radiotherapy versus radiotherapy plus androgen deprivation therapy for men with advanced prostate cancer

BACKGROUND

Men with locally advanced prostate cancer (LAPCa) or regionally advanced prostate cancer (RAPCa) are at high risk for death from their disease. Clinical guidelines support multimodal approaches, which include radical prostatectomy (RP) followed by radiotherapy (XRT) and XRT plus androgen deprivation therapy (ADT). However, there are limited data comparing these substantially different treatment approaches. Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data, this study compared survival outcomes and adverse effects associated with RP plus XRT versus XRT plus ADT in these men.

METHODS

SEER-Medicare data were queried for men with cT3-T4N0M0 (LAPCa) or cT3-T4N1M0 (RAPCa) prostate cancer. Propensity score methods were used to balance cohort characteristics between the treatment arms. Survival analyses were analyzed with the Kaplan-Meier method and Cox proportional hazards models.

RESULTS

From 1992 to 2009, 13,856 men (≥65 years old) were diagnosed with LAPCa or RAPCa: 6.1% received RP plus XRT, and 23.6% received XRT plus ADT. At a median follow-up of 14.6 years, there were 2189 deaths in the cohort, of which 702 were secondary to prostate cancer. Regardless of the tumor stage or the Gleason score, the adjusted 10-year prostate cancer-specific survival and 10-year overall survival favored men who underwent RP plus XRT over men who underwent XRT plus ADT. However, RP plus XRT versus XRT plus ADT was associated with higher rates of erectile dysfunction (28% vs 20%; P = .0212) and urinary incontinence (49% vs 19%; P < .001).

CONCLUSIONS

Men with LAPCa or RAPCa treated initially with RP plus XRT had a lower risk of prostate cancer-specific death and improved overall survival in comparison with those men treated with XRT plus ADT, but they experienced higher rates of erectile dysfunction and urinary incontinence.

Solar particle event storm shelter requirements for missions beyond low Earth orbit

Protecting spacecraft crews from energetic space radiations that pose both chronic and acute health risks is a critical issue for future missions beyond low Earth orbit (LEO). Chronic health risks are possible from both galactic cosmic ray and solar energetic particle event (SPE) exposures. However, SPE exposures also can pose significant short term risks including, if dose levels are high enough, acute radiation syndrome effects that can be mission- or life-threatening. In order to address the reduction of short term risks to spaceflight crews from SPEs, we have developed recommendations to NASA for a design-standard SPE to be used as the basis for evaluating the adequacy of proposed radiation shelters for cislunar missions beyond LEO. Four SPE protection requirements for habitats are proposed: (1) a blood-forming-organ limit of 250 mGy-equivalent for the design SPE; (2) a design reference SPE environment equivalent to the sum of the proton spectra during the October 1989 event series; (3) any necessary assembly of the protection system must be completed within 30 min of event onset; and (4) space protection systems must be designed to ensure that astronaut radiation exposures follow the ALARA (As Low As Reasonably Achievable) principle.

Abstract B211: Cellular zinc homeostatic mechanisms function as an off switch for zinc metallochaperone-mediated reactivation of mutant p53

The p53 transcription factor functions as one of cancer’s most potent tumor suppressors and is the most frequently mutated gene in human cancer. The majority of p53 mutations (&gt;70%) are missense that generate a defective protein found at high levels in cells that is targetable. Restoration of wild type structure and function of mutant p53 with a small molecule (so-called reactivation) is a highly sought after goal in anticancer drug development. The p53 protein requires the binding of a single zinc ion to fold properly, and mutations that impair the protein’s ability to bind zinc (and cause it to misfold) are highly prevalent in cancer. We recently discovered a new class of small-molecule zinc chelators named zinc metallochaperones (ZMCs) that reactivate zinc-deficient mutant p53 through a novel mechanism involving both zinc ionophore activity to raise intracellular zinc concentrations and donation to restore zinc binding to mutant p53. This induces a wild type conformation change and a p53-mediated apoptotic program. The lead compound (ZMC1) displays a transient pharmacodynamics (p21 levels) in vitro. We hypothesized that the regulation of these pharmacodynamics is governed by cellular zinc homeostatic mechanisms that function to restore zinc to its physiologic picomolar levels. We examined the entire suite of zinc homeostatic genes in response to ZMC1 and manipulated several metallothionein genes by knockout and knockdown. The net effect of this was to increase the peak and duration of intracellular zinc levels that lead to a more potent and sustained duration of p21 expression. This translated to increased sensitivity to ZMC1. We further postulated that this pharmacodynamics would allow the drug to function with very minimal exposure, and colony formation studies in vitro indicated that a 2-hour exposure was as effective as a 72-hour exposure. We then sought to translate this mechanism in vivo using a genetically engineered murine model of KPC pancreatic cancer (Pdx-1Cre; KrasG12D) that expresses either the p53R172H (zinc deficient) allele or p53R270H (non-zinc deficient). Pharmacokinetic (PK) studies of the drug revealed a short half-life (15 minutes) indicating a minimal exposure. Despite this, daily, intermittent dosing at the maximum tolerated dose resulted in a statistically significant increase in the overall survival of the KPC-p53R172H mice while having no such effect in the KPC-p53R270H. We sought to improve the efficacy of ZMC1 by preloading it with zinc in a 2:1 molar ratio based on the crystal structure. The drug-zinc complex (Zn-1) increased the median survival of KPCp53-R172H mice from 26 days to 35 days (ZMC1 monomer versus Zn-1). These studies indicate that cellular zinc homeostatic mechanisms function as an “off” switch for ZMCs, which has important implications for the translation of ZMCs in humans. Principally, this allows the drug to function with minimal exposure, which minimizes potential zinc toxicity. ZMC1 as monotherapy improves survival in an allele-specific mutant p53 manner. Furthermore, ZMC1 can be optimized by synthesizing it complexed with zinc. Overall, this “off” switch is novel for a targeted molecular therapeutic and represents a significant departure from the traditional paradigm where the goal is to develop a compound that binds the target with a PK profile that provides maximal exposure.

Citation Format: Xin Yu, Samuel Kogan, Ying Chen, Ashley T. Tsang, Tracy Withers, Hongxia Lin, Chunxia Chen, Dirk F. Moore, Joseph Bertino, Chang Chan, Darren R. Carpizo. Cellular zinc homeostatic mechanisms function as an off switch for zinc metallochaperone-mediated reactivation of mutant p53 [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr B211.

Proteomic Analysis of Brain and Cerebrospinal Fluid from the Three Major Forms of Neuronal Ceroid Lipofuscinosis Reveals Potential Biomarkers

Clinical trials have been conducted for the neuronal ceroid lipofuscinoses (NCLs), a group of neurodegenerative lysosomal diseases that primarily affect children. Whereas clinical rating systems will evaluate long-term efficacy, biomarkers to measure short-term response to treatment would be extremely valuable. To identify candidate biomarkers, we analyzed autopsy brain and matching CSF samples from controls and three genetically distinct NCLs due to deficiencies in palmitoyl protein thioesterase 1 (CLN1 disease), tripeptidyl peptidase 1 (CLN2 disease), and CLN3 protein (CLN3 disease). Proteomic and biochemical methods were used to analyze lysosomal proteins, and, in general, we find that changes in protein expression compared with control were most similar between CLN2 disease and CLN3 disease. This is consistent with previous observations of biochemical similarities between these diseases. We also conducted unbiased proteomic analyses of CSF and brain using isobaric labeling/quantitative mass spectrometry. Significant alterations in protein expression were identified in each NCL, including reduced STXBP1 in CLN1 disease brain. Given the confounding variable of post-mortem changes, additional validation is required, but this study provides a useful starting set of candidate NCL biomarkers for further evaluation.

Hypofractionated Postmastectomy Radiation Therapy Is Safe and Effective: First Results From a Prospective Phase II Trial

Purpose Conventionally fractionated postmastectomy radiation therapy (PMRT) takes approximately 5 to 6 weeks. Data supporting hypofractionated PMRT is limited. We prospectively evaluated a short course of hypofractionated PMRT, in which therapy was completed in 15 treatment days. Patients and Methods We delivered PMRT at a dose of 36.63 Gy in 11 fractions of 3.33 Gy over 11 days to the chest wall and the draining regional lymph nodes, followed by an optional mastectomy scar boost of four fractions of 3.33 Gy. Our primary end point was freedom from any grade 3 or higher toxicities. We incorporated early stopping criteria on the basis of predefined toxicity thresholds. Results We enrolled 69 women with stage II to IIIa breast cancer, of whom 67 were eligible for analysis. After a median follow-up of 32 months, there were no grade 3 toxicities. There were 29 reported grade 2 toxicities, with grade 2 skin toxicities being the most frequent (16 of 67; 24%). There were two patients with isolated ipsilateral chest wall tumor recurrences (2 of 67; crude rate, 3%). Three-year estimated local recurrence-free survival was 89.2% (95% CI, 0.748 to 0.956). The 3-year estimated distant recurrence-free survival was 90.3% (95% CI, 0.797 to 0.956). Forty-one patients had chest wall reconstructions; three had expanders removed for infection before radiation therapy. The total rate of implant loss or failure was 24% (9 of 38), and the unplanned surgical correction rate was 8% (3 of 38), for a total complication rate of 32%. Conclusion To our knowledge, our phase II prospective study offers one of the shortest courses of PMRT reported, delivered in 11 fractions to the chest wall and nodes and 15 fractions inclusive of a boost. We demonstrated low toxicity and high local control with this schedule. On the basis of our data, we have designed a cooperative group phase III prospective, randomized trial of conventional versus hypofractionated PMRT that will activate soon.

A Basic ApoE-Based Peptide Mediator to Deliver Proteins across the Blood-Brain Barrier: Long-Term Efficacy, Toxicity, and Mechanism

We have investigated delivery of protein therapeutics from the bloodstream into the brain using a mouse model of late-infantile neuronal ceroid lipofuscinosis (LINCL), a lysosomal disease due to deficiencies in tripeptidyl peptidase 1 (TPP1). Supraphysiological levels of TPP1 are delivered to the mouse brain by acute intravenous injection when co-administered with K16ApoE, a peptide that in trans mediates passage across the blood-brain barrier (BBB). Chronic treatment of LINCL mice with TPP1 and K16ApoE extended the lifespan from 126 to >294 days, diminished pathology, and slowed locomotor dysfunction. K16ApoE enhanced uptake of a fixable biotin tracer by brain endothelial cells in a dose-dependent manner, suggesting that its mechanism involves stimulation of endocytosis. Pharmacokinetic experiments indicated that K16ApoE functions without disrupting the BBB, with minimal effects on overall clearance or uptake by the liver and kidney. K16ApoE has a narrow therapeutic index, with toxicity manifested as lethargy and/or death in mice. To address this, we evaluated variant peptides but found that efficacy and toxicity are associated, suggesting that desired and adverse effects are mechanistically related. Toxicity currently precludes direct clinical application of peptide-mediated delivery in its present form but it remains a useful approach to proof-of-principle studies for biologic therapies to the brain in animal models.

Chronic Enzyme Replacement to the Brain of a Late Infantile Neuronal Ceroid Lipofuscinosis Mouse Has Differential Effects on Phenotypes of Disease

Late infantile neuronal ceroid lipofuscinosis (LINCL) is a fatal inherited neurodegenerative disease caused by loss of lysosomal protease tripeptidyl peptidase 1 (TPP1). We have investigated the effects of chronic intrathecal (IT) administration using enzyme replacement therapy (ERT) to the brain of an LINCL mouse model, in which locomotor function declines dramatically prior to early death. Median lifespan was significantly extended from 126 days to >259 days when chronic IT treatment was initiated before the onset of disease. While treated animals lived longer and showed little sign of locomotor dysfunction as measured by stride length, some or all (depending on regimen) still died prematurely. One explanation is that cerebrospinal fluid (CSF)-mediated delivery may not deliver TPP1 to all brain regions. Morphological studies support this, showing delivery of TPP1 to ventral, but not deeper and dorsal regions. When IT treatment is initiated in severely affected LINCL mice, lifespan was extended modestly in most but dramatically extended in approximately one-third of the cohort. Treatment improved locomotor function in these severely compromised animals after it had declined to the point at which animals normally die. This indicates that some pathology in LINCL is reversible and does not simply reflect neuronal death.

Abstract A22: Racial/ethnic and insurance-based disparities in receipt of long-term follow-up care information among a population-based sample of breast and colorectal cancer patients in New Jersey

Background: Follow-up information for cancer patients transitioning from active treatment to survivorship care is important for ensuring patient engagement and appropriate care coordination. Few studies have examined whether disparities exist in the receipt of information on late and long-term effects among diverse cancer patients during the initial Affordable Care Act implementation period, a time when care quality and care coordination gained increased attention.

Methods: We conducted mail surveys between September 2015 and June 2016 in a population-based sample of breast cancer (BC) and colorectal cancer (CRC) cases from the New Jersey State Cancer Registry to understand cancer care experiences. We included cases diagnosed in 2012-2014. Sampling was stratified by age (21-64 years vs. &gt; 64 years) and oversampled for cases with Medicaid coverage or uninsured at the time of diagnosis. We examined overall patient-reported responses about receiving follow-up care information and also whether receipt of follow-up information differed by race/ethnicity or insurance type. Significant differences between groups were determined at p &lt;0.05 level using chi-squared and t-tests.

Results: A total of 180 breast and 60 colorectal cancer cases participated in the study. Approximately 13% of cases were Hispanic, 7% non-Hispanic black, and 68% non-Hispanic white. At the time of diagnosis, 14% of BC and 22% of CRC patients were uninsured. A high proportion of breast cancer (84%) and colorectal (77%) cancer cases received detailed information from their cancer care provider about the need for regular follow-up care and monitoring post-treatment. Similarly, high proportions (96% and 90%) of BC and CRC patients, respectively, received written instructions on when to return for checkups. A much smaller proportion of patients of both cancer types combined reported receipt of written summaries of their cancer treatment (42%), detailed discussion with their providers about the late or long-term effects of treatment (58%) or lifestyle and health recommendations (54%). We observed significant differences in the receipt of follow-up information by insurance status but not race/ethnicity. For example, having a detailed discussion of the late or long-term side effects from treatment with providers were lower among uninsured (49%) and Medicare patients (54%) compared to privately-insured (64%) and Medicaid patients (71%). Similarly, a higher proportion of uninsured patients (34%) and Medicaid patients (30%) did not discuss the emotional of social needs related to their cancer treatment at all with their doctor compared to a lower proportion of privately-insured patients (25%).

Conclusions: Our findings from a diverse population-based sample of recently diagnosed BC and CRC cases provide insight on patient reported experiences of care during the initial Affordable Care Act implementation period. Although it is reassuring that the majority of patients received information about the need for regular follow-up and when to return for check-ups, it is alarming that roughly half of the participants in our sample did not get a summary of their treatment or detailed information from their doctor about the long-term effects of their care. These results suggest the need to improve care coordination and follow-up efforts among specific disadvantaged subgroups, particularly in settings serving uninsured or underinsured groups. Policy and intervention efforts should focus on addressing how to better coordinate care between oncologists and primary care providers, particularly for underserved cancer patients, as the number of cancer survivors continue to grow nationally.

Citation Format: Jennifer Tsui, Antoinette M. Stroup, Carolina Lozada, David Rotter, Natalia L. Herman, Dirk F. Moore, Grace L. Lu-Yao. Racial/ethnic and insurance-based disparities in receipt of long-term follow-up care information among a population-based sample of breast and colorectal cancer patients in New Jersey. [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr A22.

Accounting for Protein Subcellular Localization: A Compartmental Map of the Rat Liver Proteome

Accurate knowledge of the intracellular location of proteins is important for numerous areas of biomedical research including assessing fidelity of putative protein-protein interactions, modeling cellular processes at a system-wide level and investigating metabolic and disease pathways. Many proteins have not been localized, or have been incompletely localized, partly because most studies do not account for entire subcellular distribution. Thus, proteins are frequently assigned to one organelle whereas a significant fraction may reside elsewhere. As a step toward a comprehensive cellular map, we used subcellular fractionation with classic balance sheet analysis and isobaric labeling/quantitative mass spectrometry to assign locations to >6000 rat liver proteins. We provide quantitative data and error estimates describing the distribution of each protein among the eight major cellular compartments: nucleus, mitochondria, lysosomes, peroxisomes, endoplasmic reticulum, Golgi, plasma membrane and cytosol. Accounting for total intracellular distribution improves quality of organelle assignments and assigns proteins with multiple locations. Protein assignments and supporting data are available online through the Prolocate website (http://prolocate.cabm.rutgers.edu). As an example of the utility of this data set, we have used organelle assignments to help analyze whole exome sequencing data from an infant dying at 6 months of age from a suspected neurodegenerative lysosomal storage disorder of unknown etiology. Sequencing data was prioritized using lists of lysosomal proteins comprising well-established residents of this organelle as well as novel candidates identified in this study. The latter included copper transporter 1, encoded by SLC31A1, which we localized to both the plasma membrane and lysosome. The patient harbors two predicted loss of function mutations in SLC31A1, suggesting that this may represent a heretofore undescribed recessive lysosomal storage disease gene.

Abstract 4305: Short-term outcomes of abiraterone in community settings

Introduction: About 32% of men with high-risk prostate cancer have comorbidities, conditions that may be under-represented in randomized clinical trials (RCTs). Because men enrolled on RCTs are often excluded if they have multiple comorbidities, these patients may be at higher risk for serious toxicities from cancer therapies that the results of RCTs may not reflect. This study was undertaken to test the hypothesis that 90-day mortality rates in men undergoing treatment with abiraterone (a novel agent for treating castration-resistant prostate cancer) in the community settings is higher than that observed in the pivotal trial.

Methods: SEER-Medicare linked data with Medicare Drug Event File during the period 2006-2012 were used to identify patients who filled prescriptions for abiraterone during the study period and these patients were followed through 12/31/2013 for overall mortality. Ninety-day mortality after abiraterone initiation among patients with Charlson score 0 was compared to that in the pivotal abiraterone trial published in the New England Journal of Medicine 2011.

Results: We identified 1,106 patients who took abiraterone during the study period. Among them, 484 (43.8%) were age 75 or older at the time of abiraterone initiation and 61 (5.5%) had comorbidity score 2 or higher. Hospitalization rates among those who had abiraterone were 0.09 per person month during the 6-month window before the initiation of abiraterone and 0.12 per person month within 3 months of drug initiation. The top five diagnoses for hospital admission after drug initiation were general symptoms (ICD-9 780), malignant neoplasm of prostate (ICD-9 185), respiratory abnormality (ICD-9 786), care involving rehabilitation (ICD-9 V57), and urinary tract infection (ICD-9 599). The 90-day all-cause mortality after drug initiation was 14.5% (95% 12.4% - 16.5%) in the entire study cohort, 13.0% (95% CI 10.4% - 15.7%) among those under age 75 and 16.3% (13.0% - 19.6%) among those 75 or older. The 90-day mortality was 15.5% (95% CI 12.2% - 18.8%), 12.8% (95% CI 6.2% - 19.3%), and 18.0% (95% CI 8.3% - 27.8%) among patients with comorbidity score 0, 1, and 2+ respectively. The 90-day mortality among patients with comorbidity 0 in the community settings is substantially higher than those found in the pivotal trial abiraterone arm (risk ratio 2.03; 95% CI 1.48 - 2.78) and control arm (risk ratio 1.43; 1.01 - 2.03).

Conclusion: This first US national study shows that 90-day mortality after abiraterone among relatively healthy patients in the community settings is twice that observed in the pivotal trial abiraterone arm. Further studies are needed to improve selection of eligible patients and post-treatment monitoring.

Citation Format: Grace L. Lu-Yao, Dirk F. Moore, Yong Lin, Timothy R. Rebbeck, Kitaw Demissie, David Rotter, Kimberly A. McGuigan, Anthony V. D’Amico. Short-term outcomes of abiraterone in community settings. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4305.

Primary radiotherapy vs conservative management for localized prostate cancer--a population-based study

BACKGROUND

Radiotherapy is the most common curative cancer therapy used for elderly patients with localized prostate cancer. However, the effectiveness of this approach has not been established. The purpose of this study is to evaluate the long-term outcomes of primary radiotherapy compared with conservative management in order to facilitate treatment decisions.

METHOD

This population-based study consisted of 57,749 patients with T1-T2 prostate cancers diagnosed during 1992-2007. We utilized an instrumental variable (IV) analytical approach with competing risk models to evaluate the outcomes of primary radiotherapy vs conservative management. The IV was comprised of combined health service areas with high- and low-use areas corresponding to the top and bottom tertile in radiotherapy usage rates.

RESULTS

In patients with low-/intermediate-risk prostate cancer, 10-year prostate cancer-specific and overall survival was similar in high- and low-radiotherapy use areas (96.1 vs 95.4% and 56.6 vs 56.3%, respectively). In patients with high-risk disease, however, areas with high-radiotherapy use had a higher 10-year cancer-specific survival (90.2 vs 88.1%, difference 2.1%; 95% CI 0.3-4.0%) and 10-year overall survival (53.3 vs 50.2%, difference 3.1%; 95% CI 1.3-6.3%). Results were similar irrespective of the type of radiotherapy used. To assess the robustness of our choice of IV, we repeated the IV analytical approach using different IVs (using the median utilization rate as the cutoff) and found the results to be similar.

CONCLUSIONS

Among men >65 years of age, the benefit of primary radiotherapy for localized disease is largely confined to patients with high-risk prostate cancer (Gleason scores 7-10).

Short-Course Hypofractionated Radiation Therapy With Boost in Women With Stages 0 to IIIa Breast Cancer: A Phase 2 Trial

PURPOSE

Conventionally fractionated whole-breast irradiation (WBI) with a boost takes approximately 6 to 7 weeks. We evaluated a short course of hypofractionated (HF), accelerated WBI in which therapy was completed in 3 weeks inclusive of a sequential boost.

METHODS AND MATERIALS

We delivered a whole-breast dose of 36.63 Gy in 11 fractions of 3.33 Gy over 11 days, followed by a lumpectomy bed boost in 4 fractions of 3.33 Gy delivered once daily for a total of 15 treatment days. Acute toxicities were scored using Common Terminology Criteria for Adverse Events version 4. Late toxicities were scored using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale. Cosmesis was scored using the Harvard Cosmesis Scale. Our primary endpoint was freedom from locoregional failure; we incorporated early stopping criteria based on predefined toxicity thresholds. Cosmesis was examined as a secondary endpoint.

RESULTS

We enrolled 83 women with stages 0 to IIIa breast cancer. After a median follow-up of 40 months, 2 cases of isolated ipsilateral breast tumor recurrence occurred (2 of 83; crude rate, 2.4%). Three-year estimated local recurrence-free survival was 95.9% (95% confidence interval [CI]: 87.8%-98.7%). The 3-year estimated distant recurrence-free survival was 97.3% (95% CI: 89.8%-99.3%). Three-year secondary malignancy-free survival was 94.3% (95% CI: 85.3%-97.8%). Twenty-nine patients (34%) had grade 2 acute toxicity, and 1 patient had a late grade 2 toxicity (fibrosis). One patient had acute grade 3 dermatitis, whereas 2 patients experienced grade 3 late skin toxicity. Ninety-four percent of evaluable patients had good or excellent cosmesis.

CONCLUSIONS

Our phase 2 institutional study offers one of the shortest courses of HF therapy, delivered in 15 fractions inclusive of a sequential boost. We demonstrated expected low toxicity and high local control rates with good to excellent cosmetic outcomes. This fractionation scheme is feasible and well tolerated and offers women WBI in a highly convenient schedule.

Diagnosis and Treatment of Acute Gout at a University Hospital Emergency Department

Background :

Acute gout attacks account for a substantial number of visits to the emergency department (ED). Our aim was to evaluate acute gout diagnosis and treatment at a University Hospital ED.

Methods :

Our study was a retrospective chart review of consecutive patients with a diagnosis of acute gout seen in the ED 1/01/2004 - 12/31/2010. We documented: demographics, clinical characteristics, medications given, diagnostic tests, consultations and whether patients were hospitalized. Descriptive and summary statistics were performed on all variables.

Results :

We found 541 unique ED visit records of patients whose discharge diagnosis was acute gout over a 7 year period. 0.13% of ED visits were due to acute gout. The mean patient age was 54; 79% were men. For 118 (22%) this was their first attack. Attack duration was ≤ 3 days in 75%. Lower extremity joints were most commonly affected. Arthrocentesis was performed in 42 (8%) of acute gout ED visits.

During 355 (66%) of ED visits, medications were given in the ED and/or prescribed. An anti-inflammatory drug was given during the ED visit during 239 (44%) visits. Medications given during the ED visit included: NSAIDs: 198 (56%): opiates 190 (54%); colchicine 32 (9%) and prednisone 32 (9%). During 154 (28%) visits an anti-inflammatory drug was prescribed. Thirty two (6%) were given no medications during the ED visit nor did they receive a prescription. Acute gout rarely (5%) led to hospitalizations.

Conclusion :

The diagnosis of acute gout in the ED is commonly clinical and not crystal proven. Anti-inflammatory drugs are the mainstay of treatment in acute gout; yet, during more than 50% of ED visits, anti-inflammatory drugs were not given during the visit. Thus, improvement in the diagnosis and treatment of acute gout in the ED may be required.

Fifteen-year Outcomes Following Conservative Management Among Men Aged 65 Years or Older with Localized Prostate Cancer

BACKGROUND

To understand the threat posed by localized prostate cancer and the potential impact of surgery or radiation, patients and healthcare providers require information on long-term outcomes following conservative management.

OBJECTIVE

To describe 15-yr survival outcomes and cancer therapy utilization among men 65 years and older managed conservatively for newly diagnosed localized prostate cancer.

DESIGN, SETTINGS, AND PARTICIPANTS

This is a population-based cohort study with participants living in predefined geographic areas covered by the Surveillance, Epidemiology, and End Results program. The study includes 31 137 Medicare patients aged ≥65 yr diagnosed with localized prostate cancer in 1992-2009 who initially received conservative management (no surgery, radiotherapy, cryotherapy, or androgen deprivation therapy [ADT]). All patients were followed until death or December 31, 2009 (for prostate cancer-specific mortality [PCSM]) and December 31, 2011 (for overall mortality).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Competing-risk analyses were used to examine PCSM, overall mortality, and utilization of cancer therapies.

RESULTS AND LIMITATIONS

The 15-yr risk of PCSM for men aged 65-74 yr diagnosed with screening-detected prostate cancer was 5.7% (95% confidence interval [CI] 3.7-8.0%) for T1c Gleason 5-7 and 22% (95% CI 16-35%) for Gleason 8-10 disease. After 15 yr of follow-up, 24% (95% CI 21-27%) of men aged 65-74 yr with screening-detected Gleason 5-7 cancer received ADT. The corresponding result for men with Gleason 8-10 cancer was 38% (95% CI 32-44%). The major study limitations are the lack of data for men aged <65 yr and detailed clinical information associated with secondary cancer therapy.

CONCLUSIONS

The 15-yr outcomes following conservative management of newly diagnosed Gleason 5-7 prostate cancer among men aged ≥65 yr are excellent. Men with Gleason 8-10 disease managed conservatively face a significant risk of PCSM.

PATIENT SUMMARY

We examined the long-term survival outcomes for a large group of patients diagnosed with localized prostate cancer who did not have surgery, radiotherapy, cryotherapy, or androgen deprivation therapy in the first 6 mo after cancer diagnosis. We found that the 15-yr disease-specific survival is excellent for men diagnosed with Gleason 5-7 disease. The data support conservative management as a reasonable choice for elderly patients with low-grade localized prostate cancer.

Outcome-volume relationships and transhiatal esophagectomy: minimizing "failure to rescue"

Background

The objective of this study is to describe the system and technical factors that enabled our moderate size transhiatal esophagectomy program to achieve low mortality rates.

Methods

A retrospective chart review was conducted on 200 consecutive patients who underwent transhiatal esophagectomy at Robert Wood Johnson University Hospital. Primary outcomes included operative times, estimated blood loss, frequency and nature of complications, and lengths of stay in the hospital and the intensive care unit.

Results

In general, surgical outcomes tended to improve over the course of this study. We identified decreased operative time, intra-operative blood loss, frequency of complications, and lengths of intensive care unit and hospital stay as the program matured. Through coordinated actions of the surgical and anesthesia teams, all intraoperative injuries were responded to in an effective, emergent fashion and all but one patient was saved. This resulted in an inhospital and 30-day mortality rate of only 0.5%.

Conclusions

Our study suggests that a dual attending approach, focus on avoiding “failure to rescue”, increased volume, and a surgeon driven commitment to quality improvement may lead to low mortality rates after transhiatal esophagectomy.

Fifteen-year survival outcomes following primary androgen-deprivation therapy for localized prostate cancer

IMPORTANCE

One in 6 American men will be diagnosed as having prostate cancer during their lifetime. Although there are no data to support the use of primary androgen-deprivation therapy (ADT) for early-stage prostate cancer, primary ADT has been widely used for localized prostate cancer, especially among older patients.

OBJECTIVE

To determine the long-term survival impact of primary ADT in older men with localized (T1/T2) prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

This was a population-based cohort study of 66,717 Medicare patients 66 years or older diagnosed from 1992 through 2009 who received no definitive local therapy within 180 days of prostate cancer diagnosis. The study was conducted in predefined US geographical areas covered by the Surveillance, Epidemiology, and End Results (SEER) Program. Instrumental variable analysis was used to assess the impact of primary ADT and control for potential biases associated with unmeasured confounding variables. The instrumental variable comprised combined health services areas with various usage rates of primary ADT. The analysis compared survival outcomes in the top tertile areas with those in the bottom tertile areas.

MAIN OUTCOMES AND MEASURES

Prostate cancer-specific survival and overall survival.

RESULTS

With a median follow-up of 110 months, primary ADT was not associated with improved 15-year overall or prostate cancer-specific survival following the diagnosis of localized prostate cancer. Among patients with moderately differentiated cancers, the 15-year overall survival was 20.0% in areas with high primary ADT use vs 20.8% in areas with low use (difference: 95% CI, -2.2% to 0.4%), and the 15-year prostate cancer survival was 90.6% in both high- and low-use areas (difference: 95% CI, -1.1% to 1.2%). Among patients with poorly differentiated cancers, the 15-year cancer-specific survival was 78.6% in high-use areas vs 78.5%, in low-use areas (difference: 95% CI, -1.8% to 2.4%), and the 15-year overall survival was 8.6% in high-use areas vs 9.2% in low-use areas (difference: 95% CI, -1.5% to 0.4%).

CONCLUSIONS AND RELEVANCE

Primary ADT is not associated with improved long-term overall or disease-specific survival for men with localized prostate cancer. Primary ADT should be used only to palliate symptoms of disease or prevent imminent symptoms associated with disease progression.

Pilot study of angiogenic response to yttrium-90 radioembolization with resin microspheres

PURPOSE

To investigate the impact of radioembolization with yttrium-90 resin microspheres on the regulation of angiogenesis through observation of serial changes in a spectrum of angiogenic markers and other cytokines after therapy.

MATERIALS AND METHODS

This prospective pilot study enrolled 22 patients with liver-dominant disease deriving from biopsy-proven hepatocellular carcinoma (HCC) (n = 7) or metastatic colorectal carcinoma (mCRC) (n = 15). Circulating angiogenic markers were measured from serum samples drawn at baseline and at time points after therapy ranging from 6 hours to 120 days. Using multiplex enzyme-linked immunosorbent assay, several classic angiogenesis factors (vascular endothelial growth factor [VEGF], angiopoietin-2 [Ang-2], basic fibroblast growth factor [bFGF], platelet-derived growth factor subunit BB [PDGF-BB], thrombospondin-1 [Tsp-1]) and nonclassic factors (follistatin, leptin, interleukin [IL]-8) were evaluated.

RESULTS

Increases in cytokine levels ≥ 50% over baseline were observed in more than half of all patients studied for many cytokines, including classic angiogenic factors such as VEGF, Ang-2, and Tsp-1 as well as nonclassic factors IL-8 and follistatin (range, 36%-82% for all cytokines). Baseline cytokine levels in patients with overall survival (OS) < 6 months differed significantly from patients with longer survival for Ang-2 (P = .033) and IL-8 (P = .041). Patients with OS ≤ 6 months exhibited transient increases in VEGF and PDGF-BB after therapy compared with patients with OS > 6 months.

CONCLUSIONS

Radioembolization is associated with early transient increases in many angiogenic cytokines. In this small sample size, some of these changes were associated with worse OS. This research has important implications for future studies of radioembolization with antiangiogenic therapy performed during and after the procedure.

Cancer-specific survival after metastasis following primary radical prostatectomy compared with radiation therapy in prostate cancer patients: results of a population-based, propensity score-matched analysis

BACKGROUND

Data regarding the difference in the clinical course from metastasis to prostate cancer-specific mortality (PCSM) following radical prostatectomy (RP) compared with radiation therapy (RT) are lacking.

OBJECTIVE

To examine the association between primary treatment modality and prostate cancer-specific survival (PCSS) after metastasis.

DESIGN, SETTING, AND PARTICIPANTS

We used the Surveillance Epidemiology and End Results-Medicare linked database from 1994 to 2007 for patients diagnosed with localized prostate cancer (PCa). We used cancer stage and Gleason score to stratify patients into low and intermediate-high risks.

INTERVENTION

Radical prostatectomy or radiation therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Our outcome is time from onset of metastases to PCSM. Propensity score matching and Cox regression were used to analyze the PCSM hazard for the RP group compared with the RT group.

RESULTS AND LIMITATIONS

Our study consisted of 66,492 men diagnosed with PCa, 51,337 men receiving RT, and 15,155 men undergoing RP within 1 yr of cancer diagnosis. During the study period, 2802 men were diagnosed as having metastatic disease. A total of 916 men with metastases were included in the propensity-matched cohort; of these men, 186 died from PCa. During the follow-up, for the low-risk patients, the adjusted PCSS after metastasis was 86.2% and 79.3% in the RP and RT groups, respectively; for the intermediate-high-risk patients, the PCSS after metastasis was 76.3% and 63.3% in the RP and RT groups, respectively. The hazard ratios estimating the risk of PCSM between the RP and RT groups were 0.64 (95% confidence interval [CI], 0.36-1.16) and 0.55 (95% CI, 0.39-0.77) for the low- and intermediate-high-risk groups, respectively. Because of the nature of observational studies, the results may be affected by residual confounders and treatment indication.

CONCLUSIONS

Following the development of metastases, men who received primary RP have a longer PCSS than men who received primary RT. Our results may have implications for the timing and nature of local PCa treatment.

Extending the mannose 6-phosphate glycoproteome by high resolution/accuracy mass spectrometry analysis of control and acid phosphatase 5-deficient mice

In mammals, most newly synthesized lumenal lysosomal proteins are delivered to the lysosome by the mannose 6-phosphate (Man6P) targeting pathway. Man6P -containing proteins can be affinity-purified and characterized using proteomic approaches, and such studies have led to the discovery of new lysosomal proteins and associated human disease genes. One limitation to this approach is that in most cell types the Man6P modification is rapidly removed by acid phosphatase 5 (ACP5) after proteins are targeted to the lysosome, and thus, some lysosomal proteins may escape detection. In this study, we have extended the analysis of the lysosomal proteome using high resolution/accuracy mass spectrometry to identify and quantify proteins in a combined analysis of control and ACP5-deficient mice. To identify Man6P glycoproteins with limited tissue distribution, we analyzed multiple tissues and used statistical approaches to identify proteins that are purified with high specificity. In addition to 68 known Man6P glycoproteins, 165 other murine proteins were identified that may contain Man6P and may thus represent novel lysosomal residents. For four of these lysosomal candidates, (lactoperoxidase, phospholipase D family member 3, ribonuclease 6, and serum amyloid P component), we demonstrate lysosomal residence based on the colocalization of fluorescent fusion proteins with a lysosomal marker.

Fracture after androgen deprivation therapy among men with a high baseline risk of skeletal complications

WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Receipt of androgen deprivation therapy (ADT) has been associated with an increased risk of skeletal-associated complications, such as a decrease in bone mineral density and an increase in fracture risk. Many men with pre-existing health conditions receive ADT as their primary treatment because they are considered to be inappropriate candidates for attempted curative treatments. However, several chronic health conditions, such as diabetes, rheumatoid disease and chronic liver disease, are strong predictors for osteoporosis and fractures. We undertook the present study aiming to quantify the impact of treating men with ADT who carry known risk factors for skeletal complications. Among these high-risk men, more than 58% develop at least one fracture after ADT within the 12 years of follow-up. Men who sustained a fracture within 48 months experienced an almost 40% higher risk of mortality than those who did not. Our findings suggest that treating men with a high fracture risk at baseline with long-term ADT may have serious adverse consequences.

OBJECTIVE

To quantify the impact of androgen deprivation therapy (ADT) in men with a high baseline risk of skeletal complications and evaluate the risk of mortality after a fracture.

PATIENTS AND METHODS

We studied 75994 men, aged ≥ 66 years, with localized prostate cancer from the Surveillance, Epidemiology and End Results-Medicare linked data. Cox proportional hazard models were employed to evaluate the risk.

RESULTS

Men with a high baseline risk of skeletal complications have a higher probability of receiving ADT than those with a low risk (52.1% vs 38.2%, P < 0.001). During the 12-year follow-up, more than 58% of men with a high risk and 38% of men with a low risk developed at least one fracture after ADT. The dose effect of ADT is stronger among men who received ADT only compared to those who received ADT with other treatments. In the high-risk group, the fracture rate increased by 19.9 per 1000 person-years (from 52.9 to 73.0 person-years) for men who did not receive ADT compared to those who received 18 or more doses of gonadotropin-releasing hormone agonist among men who received ADT only, and by 14.2 per 1000 person-years (from 45.2 to 59.4 person-years) among men who received ADT and other treatments. Men experiencing a fracture had a 1.38-fold higher overall mortality risk than those who did not (95% CI, 1.34-1.43).

CONCLUSIONS

Men with a high baseline risk of skeletal complications developed more fractures after ADT. The mortality risk is 40% higher after experiencing a fracture. Consideration of patient risk before prescribing ADT for long-term use may reduce both fracture risk and fracture-associated mortality.

Physical dynamics controlling variability in nearshore fecal pollution: fecal indicator bacteria as passive particles

We present results from a 5-h field program (HB06) that took place at California's Huntington State Beach. We assessed the importance of physical dynamics in controlling fecal indicator bacteria (FIB) concentrations during HB06 using an individual based model including alongshore advection and cross-shore variable horizontal diffusion. The model was parameterized with physical (waves and currents) and bacterial (Escherichia coli and Enterococcus) observations made during HB06. The model captured surfzone FIB dynamics well (average surfzone model skill: 0.84 {E. coli} and 0.52 {Enterococcus}), but fell short of capturing offshore FIB dynamics. Our analyses support the hypothesis that surfzone FIB variability during HB06 was a consequence of southward advection and diffusion of a patch of FIB originating north of the study area. Offshore FIB may have originated from a different, southern, source. Mortality may account for some of the offshore variability not explained by the physical model.

Proteomic analysis of mouse models of Niemann-Pick C disease reveals alterations in the steady-state levels of lysosomal proteins within the brain

Niemann-Pick C disease (NPC) is a neurodegenerative lysosomal disorder characterized by storage of cholesterol and other lipids caused by defects in NPC1, a transmembrane protein involved in cholesterol export from the lysosome, or NPC2, an intralysosomal cholesterol transport protein. Alterations in lysosomal activities have been implicated in NPC pathogenesis therefore the aim of this study was to conduct a proteomic analysis of lysosomal proteins in mice deficient in either NPC1 or NPC2 to identify secondary changes that might be associated with disease. Lysosomal proteins containing the specific mannose 6-phosphate modification were purified from wild-type and Npc1(-/-) and Npc2(-/-) mutant mouse brains at different stages of disease progression and identified by bottom-up LC-MS/MS and quantified by spectral counting. Levels of a number of lysosomal proteins involved in lipid catabolism including prosaposin and the two subunits of β-hexosaminidase were increased in both forms of NPC, possibly representing a compensatory cellular response to the accumulation of glycosphingolipids. Several other lysosomal proteins were significantly altered, including proteases and glycosidases. Changes in lysosomal protein levels corresponded with similar alterations in activities and transcript levels. Understanding the rationale for such changes may provide insights into the pathophysiology of NPC.

Severe genitourinary toxicity following radiation therapy for prostate cancer--how long does it last?

PURPOSE

Radiation therapy is a common treatment for localized prostate cancer but long-term data are sparse on treatment related toxicity compared to observation. We evaluated the time course of grade 2-4 genitourinary toxicities in men treated with primary radiation or observation for T1-T2 prostate cancer.

MATERIALS AND METHODS

We performed a population based cohort study using Medicare claims data linked to SEER (Surveillance, Epidemiology and End Results) data. Cumulative incidence functions for time to first genitourinary event were calculated based on the competing risks model with death before any genitourinary event as a competing event. The generalized estimating equation method was used to evaluate the risk ratios of recurrent events.

RESULTS

Of the study patients 60,134 received radiation therapy and 25,904 underwent observation. The adjusted risk ratio for genitourinary toxicity was 2.49 (95% CI 2.00-3.11) for 10 years and thereafter. Patients who had required prior procedures for obstruction/stricture, including transurethral prostate resection, before radiation therapy were at significantly increased risk for genitourinary toxicity (risk ratio 2.78, 95% CI 2.56-2.94).

CONCLUSIONS

This study demonstrates that the increased risk of grade 2-4 genitourinary toxicities attributable to radiation therapy persists 10 years after treatment and thereafter. Patients who required prior procedures for obstruction/stricture were at higher risk for genitourinary toxicity than those without these preexisting conditions.

Does primary androgen-deprivation therapy delay the receipt of secondary cancer therapy for localized prostate cancer?

BACKGROUND

Despite evidence that shows no survival advantage, many older patients receive primary androgen-deprivation therapy (PADT) shortly after the diagnosis of localized prostate cancer (PCa).

OBJECTIVE

This study evaluates whether the early use of PADT affects the subsequent receipt of additional palliative cancer treatments such as chemotherapy, palliative radiation therapy, or intervention for spinal cord compression or bladder outlet obstruction.

DESIGN, SETTING, AND PARTICIPANTS

This longitudinal population-based cohort study consists of Medicare patients aged ≥ 66 yr diagnosed with localized PCa from 1992 to 2006 in areas covered by the Surveillance Epidemiology and End Results (SEER) program. SEER-Medicare linked data through 2009 were used to identify the use of PADT and palliative cancer therapy.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Instrumental variable analysis methods were used to minimize confounding effects. Confidence intervals were derived from the bootstrap estimates.

RESULTS AND LIMITATIONS

This study includes 29 775 men who did not receive local therapy for T1-T2 PCa within the first year of cancer diagnosis. Among low-risk patients (Gleason score 2-7 in 1992-2002 and Gleason score 2-6 in 2003-2006) with a median age of 78 yr and a median follow-up of 10.3 yr, PADT was associated with a 25% higher use of chemotherapy (hazard ratio [HR]: 1.25; 95% confidence interval [CI], 1.08-1.44) and a borderline higher use of any palliative cancer treatment (HR: 1.07; 95% CI, 0.97-1.19) within 10 yr of diagnosis in regions with high PADT use compared with regions with low PADT use. Because this study was limited to men >65 yr, the results may not be applicable to younger patients.

CONCLUSIONS

Early treatment of low-risk, localized PCa with PADT does not delay the receipt of subsequent palliative therapies and is associated with an increased use of chemotherapy.

Late gastrointestinal toxicities following radiation therapy for prostate cancer

BACKGROUND

Radiation therapy is commonly used to treat localized prostate cancer; however, representative data regarding treatment-related toxicities compared with conservative management are sparse.

OBJECTIVE

To evaluate gastrointestinal (GI) toxicities in men treated with either primary radiation or conservative management for T1-T2 prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

We performed a population-based cohort study, using Medicare claims data linked to the Surveillance Epidemiology and End Results data. Competing risk models were used to evaluate the risks.

MEASUREMENTS

GI toxicities requiring interventional procedures occurring at least 6 mo after cancer diagnosis.

RESULTS AND LIMITATIONS

Among 41,737 patients in this study, 28,088 patients received radiation therapy. The most common GI toxicity was GI bleeding or ulceration. GI toxicity rates were 9.3 per 1000 person-years after three-dimensional conformal radiotherapy, 8.9 per 1000 person-years after intensity-modulated radiotherapy, 5.3 per 1000 person-years after brachytherapy alone, 20.1 per 1000 person-years after proton therapy, and 2.1 per 1000 person-years for conservative management patients. Radiation therapy is the most significant factor associated with an increased risk of GI toxicities (hazard ratio [HR]: 4.74; 95% confidence interval [CI], 3.97-5.66). Even after 5 yr, the radiation group continued to experience significantly higher rates of new GI toxicities than the conservative management group (HR: 3.01; 95% CI, 2.06-4.39). Because our cohort of patients were between 66 and 85 yr of age, these results may not be applicable to younger patients.

CONCLUSIONS

Patients treated with radiation therapy are more likely to have procedural interventions for GI toxicities than patients with conservative management, and the elevated risk persists beyond 5 yr.

Treatment profile and complications associated with cryotherapy for localized prostate cancer: a population-based study

The aim of this study was to assess the treatment patterns and 3-12-month complication rates associated with receiving prostate cryotherapy in a population-based study. Men >65 years diagnosed with incident localized prostate cancer in Surveillance Epidemiology End Results (SEER)-Medicare-linked database from 2004 to 2005 were identified. A total of 21,344 men were included in the study, of which 380 were treated initially with cryotherapy. Recipients of cryotherapy versus aggressive forms of prostate therapy (ie, radical prostatectomy or radiation therapy) were more likely to be older, have one co-morbidity, low income, live in the South and be diagnosed with indolent cancer. Complication rates increased from 3 to 12 months following cryotherapy. By the twelfth month, the rates for urinary incontinence, lower urinary tract obstruction, erectile dysfunction and bowel bleeding reached 9.8, 28.7, 20.1 and 3.3%, respectively. Diagnoses of hydronephrosis, urinary fistula or bowel fistula were not evident. The rates of corrective invasive procedures for lower urinary tract obstruction and erectile dysfunction were both <2.9% by the twelfth month. Overall, complications post-cryotherapy were modest; however, diagnoses for lower urinary tract obstruction and erectile dysfunction were common.

Patterns and correlates of prostate cancer treatment in older men

BACKGROUND

Although elderly men, particularly patients with low-risk prostate cancer and a life expectancy less than 10 years, are unlikely to benefit from prostate cancer active therapy, treatment rates in this group are high.

METHODS

By using the population-based Surveillance, Epidemiology, and End Results program linked to Medicare data from 2004 to 2005, we examined the effects of clinical and nonclinical factors on the selection of prostate cancer active therapy (ie, radical prostatectomy, external beam radiation therapy, brachytherapy, or androgen deprivation therapy) in men aged≥75 years with a new diagnosis of localized prostate cancer. Multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for receiving prostate cancer active therapy.

RESULTS

The majority of men aged≥75 years were treated with prostate cancer active therapy (81.7%), which varied by disease risk level: low, 72.2%; intermediate, 83.7%; and high, 86.4%. Overall, in older men, the percentage of the total variance in the use of prostate cancer active therapy attributable to clinical and nonclinical factors was minimal, 5.1% and 2.6%, respectively. In men with low-risk disease, comorbidity status did not affect treatment selection, such that patients with 1 or 2+ comorbidities were as likely to receive prostate cancer active therapy as healthy men: OR=0.98; 95% CI, 0.76-1.27 and OR=1.19; 95% CI, 0.84-1.68, respectively. Geographic location was the most powerful predictor of treatment selection (Northeast vs Greater California: OR=2.41; 95% CI, 1.75-3.32).

CONCLUSION

Clinical factors play a limited role in treatment selection among elderly patients with localized prostate cancer.

Impact of comorbidity on survival among men with localized prostate cancer

PURPOSE

To provide patients and clinicians more accurate estimates of comorbidity-specific survival stratified by patient age, tumor stage, and tumor grade.

PATIENTS AND METHODS

We conducted a 10-year competing risk analysis of 19,639 men 66 years of age and older identified by the Surveillance, Epidemiology, and End Results (SEER) program linked to Medicare program files. All men were diagnosed with localized prostate cancer and received no surgery or radiation within 180 days of diagnosis. The analysis was stratified by tumor grade and stage and by age and comorbidity at diagnosis classified using the Charlson comorbidity index. Underlying causes of death were obtained from SEER.

RESULTS

During the first 10 years after diagnosis, men with moderately and poorly differentiated prostate cancer were more likely to die from causes other than their disease. Depending on patient age, Gleason score, and number of comorbidities present at diagnosis, 5-year overall mortality rates for men with stage T1c disease ranged from 11.7% (95% CI, 10.2% to 13.1%) to 65.7% (95% CI, 55.9% to 70.1%), and prostate cancer-specific mortality rates ranged from 1.1% (95% CI, 0.0% to 2.7%) to 16.3% (95% CI, 13.8% to 19.4%). Ten-year overall mortality rates ranged from 28.8% (95% CI, 25.3% to 32.6%) to 94.3% (95% CI, 87.4% to 100%), and prostate cancer-specific mortality rates ranged from 2.0% (95% CI, 0.0% to 5.3%) to 27.5% (95% CI, 21.5% to 36.5%).

CONCLUSION

Patients and clinicians should consider using comorbidity-specific data to estimate the threat posed by newly diagnosed localized prostate cancer and the threat posed by competing medical hazards.

Classification of subcellular location by comparative proteomic analysis of native and density-shifted lysosomes

One approach to the functional characterization of the lysosome lies in the use of proteomic methods to identify proteins in subcellular fractions enriched for this organelle. However, distinguishing between true lysosomal residents and proteins from other cofractionating organelles is challenging. To this end, we implemented a quantitative mass spectrometry approach based on the selective decrease in the buoyant density of liver lysosomes that occurs when animals are treated with Triton-WR1339. Liver lysosome-enriched preparations from control and treated rats were fractionated by isopycnic sucrose density gradient centrifugation. Tryptic peptides derived from gradient fractions were reacted with isobaric tag for relative and absolute quantitation eight-plex labeling reagents and analyzed by two-dimensional liquid chromatography matrix-assisted laser desorption ionization time-of-flight MS. Reporter ion intensities were used to generate relative protein distribution profiles across both types of gradients. A distribution index was calculated for each identified protein and used to determine a probability of lysosomal residence by quadratic discriminant analysis. This analysis suggests that several proteins assigned to the lysosome in other proteomics studies are not true lysosomal residents. Conversely, results support lysosomal residency for other proteins that are either not or only tentatively assigned to this location. The density shift for two proteins, Cu/Zn superoxide dismutase and ATP-binding cassette subfamily B (MDR/TAP) member 6, was corroborated by quantitative Western blotting. Additional balance sheet analyses on differential centrifugation fractions revealed that Cu/Zn superoxide dismutase is predominantly cytosolic with a secondary lysosomal localization whereas ATP-binding cassette subfamily B (MDR/TAP) member 6 is predominantly lysosomal. These results establish a quantitative mass spectrometric/subcellular fractionation approach for identification of lysosomal proteins and underscore the necessity of balance sheet analysis for localization studies.

Abstract B11: Risk of fracture and androgen deprivation therapy

Background: Extended use of androgen deprivation therapy (ADT) is common among elderly men; however, the associated long-term toxic effects have not been well documented.

Methods: We conducted a population based cohort study by analyzing a total of 46,587 men diagnosed with localized prostate cancer and survived at least 5 years after diagnosis in the Surveillance, Epidemiology, and End Results (SEER) -Medicare program to estimate the risk of fracture among men who received long-term ADT.

Results: More than 46% of ADT users received more than 25 months of treatment. The hazard ratio (HR) of hospitalized fracture was 1.47 (95 percent confidence interval, 1.29 to 1.67) among men receiving 36 or more doses of Gonadotropin-releasing hormone (Gn-RH) agonist. Men treated with ADT were associated with a 57.8% increase in the risk of multiple fractures after the first 24 months of treatment. Older age, higher comorbidity, history of fracture and stoke were independently associated with increased fracture risk. Men who were 75 years of age or older and received GnRH agonist for more than 24 months were associated with a 3.63 times risk of having fracture, compared with those aged 66 to 74 and have ADT shorter than 24 months.

Conclusion: Men who are older and with comorbidity are more likely to received long-term ADT than attempted curative treatment. However, those men are also at substantial risk of fracture. The increased risk of fracture along with ADT should be carefully evaluated before initiating a treatment.

Citation Information: Cancer Prev Res 2010;3(12 Suppl):B11.

Occupational exposure to organic solvents during bridge painting

Exposure to volatile organic compounds (VOCs) from bridge painting was measured in New York City and New Jersey during the summer and fall seasons from 2005 to 2007. The effect of painting activities (paint coating layer, confinement setup, and application method) and meteorological conditions (temperature, humidity, and wind speed) on solvent exposure to aromatic, ketone, ester, and alkane compounds were individually evaluated. Mixed-effect models were used to examine the combination effects of these factors on the air concentration of total VOCs as the individual compound groups were not present in all samples. Air concentration associated with spraying was not affected by meteorological conditions since spraying was done in a confined space, thus reducing their impact on solvent air concentration. The mixed models for brushing and rolling samples included two fixed factors, i.e. application method and temperature, and one random factor, i.e. sampling day. An independent dataset (daily air samples) was used to validate the mixed model constructed for brushing and rolling samples. The regression line of the predicted values and actual measurements had a slope of 1.32 +/- 0.15 for daily brushing and rolling samples, with almost all points being within the 95% confidence bands. The constructed model provides practical approaches for estimating the solvent exposure from brushing and rolling activities among construction painters. An adjusted mean air concentration derived from the activity-specific spray samples was the best estimate for that painting application.