Citations

AbstractAimRestorative proctocolectomy with ileal‐pouch anal anastomosis is the procedure of choice for ulcerative colitis. Unfortunately, up to 10% of pouches will fail, requiring either reconstruction or excision. While several series have reported on the aetiology of pouch failure, no study to date has focused on the postoperative complications associated with pouch excision.MethodsPatients who had excision of ileoanal reservoir with ileostomy (CPT code 45136) were included. Data abstracted included preoperative, operative and postoperative variables. A Kaplan–Meier curve of pouch survival was performed.ResultsIn all, 147 patients met the inclusion criteria for the study. The median age of patients was 47 years (73 women), and 132 had a diagnosis of ulcerative colitis at the time of colectomy. The most common indications for pouch excision were sepsis (n = 46; 31%) and Crohn's disease (n = 37; 25%). 84 (57%) patients experienced short‐term (< 30 days) postoperative complications, the most common of which was a surgical site infection (n = 32; 21%); 55 (37%) patients had long‐term complications (> 30 days) postoperatively, the most common of which was a return to the operating room (n = 19; 13%) largely for perineal wounds. Thirty‐day mortality was zero. 4.8%, 47.6%, 65.3% and 84.4% of patients had undergone pouch excision by 1, 5, 10 and 20 years from the time of pouch construction, respectively.ConclusionsPouch excision has a high rate of both short‐ and long‐term postoperative complications. Patients should be appropriately counselled to set expectations accordingly. In view of these findings we suggest that this operation should ideally be performed at a high volume centre with the availability of a multidisciplinary surgical team.

SummaryCD49d is a surface integrin that is expressed on chronic lymphocytic leukaemia (CLL) cells, and strongly correlates with more aggressive disease. Given its association with cell‐cell adhesion and leucocyte trafficking, we hypothesized that patients with high CD49d expression would experience a clinical course dominated by lymphadenopathy. CD49d expression was measured by flow cytometry and considered positive if expressed by ≥30% of CLL cells. The study included 797 newly diagnosed CLL/small lymphocytic leukaemia patients; 279 (35%) were CD49d positive. CD49d‐positive patients were more likely to present with lymphadenopathy (P < 0·001); a finding that persisted after adjusting for fluorescence in situ hybridisation (FISH) and IGHV mutation status [odds ratio (OR) 2·51; 95% confidence interval (CI) 1·64–3·83; P < 0·001]. Among CLL Rai 0 patients, CD49d positivity was associated with shorter time to development of lymphadenopathy (3·2 years vs not reached, P < 0·01). This association was maintained after adjusting for either FISH [hazard ratio (HR) 2·18; 95% CI 1·25–3·81; P = 0·006) or IGHV status (HR 2·02; 95% CI 1·11–3·69; P = 0·02) individually, but was attenuated when adjusting by both (HR 1·72; 95% CI 0·88–3·38; P = 0·11).These data demonstrate that CD49d‐positive CLL patients experience a disease course dominated by lymphadenopathy. These findings could have implications for therapy selection and disease monitoring.

Background— It is not known whether abnormal blood pressure (BP) responses during dobutamine stress echocardiography (DSE) are associated with abnormal test results, nor if such results indicate obstructive coronary artery disease (CAD). We sought to define the frequency of abnormal BP responses during DSE and their impact on accuracy of test results. Methods and Results— We studied 21 949 patients who underwent DSE at Mayo Clinic, Rochester, MN, grouped by peak systolic BP achieved during the test. We also analyzed a subgroup who underwent coronary angiography within 30 days after positive DSE. The positive predictive value of DSE was calculated for each BP group. Patients with hypertensive response (n=1905; 9%) were more likely to have positive DSE than those with normal (n=19 770; 90%) or hypotensive (n=274; 1%) BP responses (32% versus 21% versus 23%, respectively; P <0.0001). Angiography, performed in 1126 patients, showed obstructive CAD (≥50% stenosis) in 814 patients and severe CAD (≥70% stenosis) in 708 patients. Positive predictive value of DSE was similar for patients who had hypertensive and normal BP responses (69% versus 73%; P =0.3), considering 50% stenosis cut point. The proportion of severe CAD (≥70% stenosis) was lower in patients who had hypertensive response compared with those who had normal BP response (54% versus 65%; P =0.005). Conclusions— Patients with hypertensive response during DSE are more likely to have stress-induced myocardial ischemia compared with those with normal or hypotensive BP responses but are not more likely to have false-positive DSE results. They are, however, less likely to have higher grade or multivessel CAD.

668 Background: Ramucirumab is a human IgG1 monoclonal antibody antagonist of VEGFR-2. Overall survival (OS) and progression-free survival (PFS) in 2nd line FOLFIRI based treatment for metastatic colorectal cancer (mCRC) were improved with RAM therapy versus PBO in the RAISE trial. Recent work suggests mCRC primary tumor location is both prognostic and predictive; with improved OS and therapy-specific sensitivity observed in left (L)- vs right (R)-sided tumors. Given these findings, the RAISE trial data was subjected to post-hoc analysis to determine if sidedness influenced RAM efficacy. Methods: Primary tumor site was obtained. L-CRC was defined as the splenic flexure, descending and sigmoid colon, and rectum, while R-CRC included transverse, ascending colon and cecum. OS/PFS in L and R subgroups were analyzed via Kaplan-Meier method and unstratified log-rank test (treatments within subgroup), unstratified Cox proportional hazards model (estimate hazard ratio [HR] and 95% CI), and Wald test (treatment-by-subgroup interaction). Results: Tumor location was available for 1012/1072 (94%) patients, 699 L- and 313 R-CRC. Baseline characteristics were balanced between arms. RAM treatment enhanced L-CRC median OS by 2.5 mo (median 14.5 vs 12.0 mo) with a HR (95% CI) = 0.807 (0.675, 0.965), P = 0.019; compared to a 1.1 mo increase in median OS in R-CRC vs PBO (12.7 vs 11.6) with a HR (95% CI) = 0.971 (0.750, 1.258), P = 0.823; and, RAM enhanced L-CRC median PFS by 1.6 mo (6.0 vs 4.4 mo) and HR (95% CI) = 0.776 (0.664, 0.906), P = 0.001 compared to a 1.1 mo increase in median PFS R-CRC vs PBO (5.6 vs 4.5) with a HR (95% CI) = 0.855 (0.674, 1.084), P = 0.197. The treatment-by-subgroup interaction for both OS and PFS was not significant ( P = 0.276, 0.578, respectively). Conclusions: Despite L-CRC patients having longer OS/PFS and a seemingly stronger RAM treatment effect than R-CRC, the non-significant interaction test cannot verify sidedness as being predictive of RAM efficacy. The current study confirms ramucirumab benefits mCRC patients regardless primary tumor location. Clinical trial information: NCT01183780.

576 Background: Anal squamous cell carcinoma (ASCC) is rare, accounting for 1% of gastrointestinal malignancies, but the incidence is rising. Risk factors for the development of ASCC in patients with Crohn’s disease (CD) include immunotherapy, increased duration of disease, and chronic fistulizing perianal disease. We sought to understand management strategies for ASCC in the setting of CD. Methods: A retrospective review from 2001-2016 was conducted for ICD-9/10 codes pertaining to Crohn’s disease (CD) (555.9/ K50) and ASCC (154.3/C44.520). Adult patients with a diagnosis of CD at the time of ASCC diagnosis were included. Results: A total of 7 patients (5 female) were included with a median age of 50 years. The majority presented with perianal pain (4) and bleeding (3). The mean duration of CD was 20 years, and all patients had perianal disease for > 10 years. Five patients had perianal fistulizing disease at the time of ASCC presentation. Clinical stage at diagnosis of ASCC was stage 0 (n = 1), I (n = 1), II (n = 1), III (n = 2), IV (n = 1), and unknown (n = 1). All patients were treated with Nigro protocol which included radiation (50-55Gy), 5-fluorouracil, and mitomycin; 1 patient received cisplatin due to concurrent Non-Hodgkin’s Lymphoma. Three patients required fecal diversion during radiation due to significant perianal disease. Two patients experienced complications related to radiation including anal and vaginal stenosis and an anovaginal fistula. One additional patient required an APR with rectus abdominis myocutaneous flap for uncontrolled CD after treatment. During follow-up, 3 of the 7 patients undergoing definitive chemoradiation developed residual or recurrent disease and required salvage APR. All patients were alive at last follow-up, 2 with metastatic disease. 5-year disease free survival was 56%. Conclusions: Patients with ASCC in the setting of CD may be managed with the standard Nigro protocol, but complications from radiation are common in this setting. Three of seven patients required salvage surgery for residual or recurrent disease, and an additional patient required APR for palliation of CD symptoms. Given the aggressive nature of ASCC in this population, surveillance guidelines are necessary.

Abstract Breast cancer risks conferred by many germline missense variants in the BRCA1 and BRCA2 genes, often referred to as variants of uncertain significance (VUS), have not been established. In this study, associations between 19 BRCA1 and 33 BRCA2 missense substitution variants and breast cancer risk were investigated through a breast cancer case–control study using genotyping data from 38 studies of predominantly European ancestry (41,890 cases and 41,607 controls) and nine studies of Asian ancestry (6,269 cases and 6,624 controls). The BRCA2 c.9104A&gt;C, p.Tyr3035Ser (OR = 2.52; P = 0.04), and BRCA1 c.5096G&gt;A, p.Arg1699Gln (OR = 4.29; P = 0.009) variant were associated with moderately increased risks of breast cancer among Europeans, whereas BRCA2 c.7522G&gt;A, p.Gly2508Ser (OR = 2.68; P = 0.004), and c.8187G&gt;T, p.Lys2729Asn (OR = 1.4; P = 0.004) were associated with moderate and low risks of breast cancer among Asians. Functional characterization of the BRCA2 variants using four quantitative assays showed reduced BRCA2 activity for p.Tyr3035Ser compared with wild-type. Overall, our results show how BRCA2 missense variants that influence protein function can confer clinically relevant, moderately increased risks of breast cancer, with potential implications for risk management guidelines in women with these specific variants. Cancer Res; 77(11); 2789–99. ©2017 AACR.

Abstract The extracellular matrix (ECM) is increasingly recognized as having a key role in cancer development. Advances in biomaterials design and preparation have led to highly defined sophisticated platforms that can recapitulate key features of the complex tumor microenvironment. We have developed a biomaterial tumor mimic that recapitulates systematically the main characteristics and heterogeneities of glioblastoma ECM. With the use of these 3D in vitro platforms we seek to understand the key features that make this cancer so challenging to treat. We are using this device in three different ways: (1) to further understand how particularities of brain tumor ECM affect cancer cells and assist in the diagnostic of different GBM tumor types, (2) provide new models for drug screening to afford more personalized therapies and (3) study the mechanisms of resistance to current therapies in order to identify more effective combinatorial treatments and new therapeutic targets. Glioblastoma (GBM) tumors are highly heterogeneous, both cell composition and ECM biophysical properties are key factors in cancer cell malignancy and treatment outcomes. Hyaluronic acid (HA), is the main component of the brain extracellular matrix and GBM is associated with aberrant HA secretion and overexpression of receptors associated with HA, such as CD44 and EGFR. We use a microfluidic system to culture GBM patient-derived cells within gelatin based hydrogels that contained gradually increasing concentrations of HA, in order to recreate the heterogeneity of the tumor mass. Cell proliferation and gene expression analyses demonstrate that biomimetic hydrogels support xenograft culture; cells remain viable, active, and upregulate matrix remodeling genes and others related to tumor growth. More importantly, we found that GBM cells respond to changes in the ECM composition presenting different gene expression profiles (VEGF, IL6, MMP2, MMP9, HAS3, CD44) depending on the particularities of every tumor, such as EGFR overexpression or PTEN suppression. These findings pave the way for new clinical tools that allow a more precise cataloging of GBM tumor types and tailoring treatments to individual patients. We have also used these platforms to evaluate potential therapeutic strategies for different GBM xenograft cells and to study the mechanisms of cell resistance. For this purpose, we first focused on the epidermal growth factor receptor (EGFR), which has been identified as a molecular target and associated with worse clinical outcomes. Amplification, overexpression and mutation of the EGFR tyrosine kinase has been identified in 50% of GBM patients. The genetic aberration of EGFR (EGFR+) often comes with the overexpression of the mutant EGFR variant III (EGFRvIII). We characterized the 3D in vitro behavior of 3 patient-derived xenografts that represent these EGFR variants: GBM10 (EGFR, wild type), GBM12 (EGFR+) and GBM6 (EGFRvIII). We studied the relationship between the HA contained in the surrounding matrix and response of GBM cells to a tyrosine kinase inhibitor (TKI), erlotinib. We demonstrate that an interaction exists between CD44 and EGF receptors. Results indicate that while EGFR+ cells are sensitive to TKI in HA hydrogels, HA seems to collaborate with EGFRvIII signaling to stir cell activity. Our results indicate that a combination of both bound and cell secreted soluble HA may influence GBM sensitivity and resistance to erlotinib. Moreover, immunoblots that analyze PI3K pathway support the hypothesis that matrix-bound HA is a key factor in the negative response of vIII tumors to EGFR inhibitors, and that the benefits of EGFR inhibition in GBMs may be found in combination to other inhibitors of ECM signaling. In summary, we demonstrate that engineered tumor avatar biomaterials can be used to reproduce some of the main characteristics of brain tumor microenvironment and become a valuable tool in the mechanistic studies of tumor development and treatment efficacy. Citation Format: Sara Pedron, Amanda M. Pritchard, Jann N. Sarkaria, Mark A. Schroeder, Brendan A. Harley. Engineered biomaterials as essential tools to determine the mechanisms of resistance to tyrosine kinase inhibitors in glioblastoma. [abstract]. In: Proceedings of the AACR Special Conference on Engineering and Physical Sciences in Oncology; 2016 Jun 25-28; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2017;77(2 Suppl):Abstract nr B05.

Abstract Background: While genomic alterations are central players in tumor progression, proteins are the targets for precision therapy. The degree by which “actionable” genomic alterations translate into activated/altered proteins and pathway is still under investigation. Using a multi-OMIC approach from the SideOut 2 metastatic breast cancer (MBC) trial, this study explored the concordance between selected “actionable” genomic alterations and protein expression/activation. Methods: Snap frozen biopsies from 29 MBC patients enrolled in a prospective phase II trial were used for this analysis. Exome WES and RNASeq data was processed using an in-house developed pipeline and identified amplification of CCND1 (6/29), FGFR1 (4/29), and FGF 3, 4, 5, and 19 (4/29) as some of most frequent “actionable” genomic alterations in our MBC cohort. Signaling analysis of the 29 cases was performed using Reverse Phase Protein Microarray coupled with Laser Capture Microdissection. Protein expression/phosphorylation was measured in a continuous scale and classified based on quartile distribution. Concordance between CCND1 amplification and Cyclin D1 expression, along with the activation of FOXM1 T600 and Rb S780, was explored. Amplification of the FGFR1 locus or its ligands was correlated with the level of activation/phosphorylation of FGFR1 Y653/654. Results: While Cyclin D1 protein expression was greater than the population mean for 4/6 (67%) patients with CCND1 amplification, only 2/6 (33%) patients with CCND1 amplification had Cyclin D1 level within the top quartile of the population (n=29). FOXM1 T600 activation was independent from CCND1 amplification, with high levels of FOXM1 T600 predominantly in the CCND1 wild-type population. Only 1/6 (17%) patients with CCND1 amplification had FOXM1 T600 level similar to the top quartile of the population while a second patient was above the population median. Activation of Rb S780 was above the population median, but below the top quartile, in 2/6 (33%) CCND1 amplified patients. Similarly, none of the patients with activation of FGFR Y653/654 equal to the top quartile harbored an FGFR1 amplification. Only 1/4 (25%) patients carrying an FGFR1 amplification had an activation of FGFR Y653/654 above the population median. Similarly, 1/4 (25%) patients with FGF ligand amplification showed FGFR Y653/654 level within the top quartile while three patients had FGFR Y653/654 activation below the population median. No significant results were found between proteomic (below/above the median) and genomic characteristics by Fisher test (p&gt;0.05). Conclusion: Molecular genotyping of “actionable” cancer targets alone may be insufficient in predicting whether the actual drug target protein is expressed and/or activated in any given patient's tumor. Although these results need further validation, the combination of genomic and proteomic data may represent a more informative approach for identifying real molecular drivers of individual lesions as well as “actionable” protein/phosphoprotein targets in the absence of genomic events. Multi-OMIC approaches may lead to more effective stratification in precision medicine trials. Citation Format: Pierobon M, Wong S, Reeded A, Anthony S, Robert N, Northfelt DW, Jahanzeb M, Vocila L, Wulfkuhle J, Dunetz B, Aldrich J, Byron S, Craig D, Liotta L, Carpten J, Petricoin EF. A multi-OMIC analysis to explore the impact of “actionable” genomic alterations on protein pathway activation: Clinical implication for precision medicine in metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-07-09.