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Gastrointestinal Cancers in Young Survivors of Lymphoma: Implications for Earlier Screening
ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS of apoptosis, which is the predominate mode of hepatocellular death from IRI. the goal of the present study was to investigate the role of BH3-only proteins in IRI utilizing a murine model of diet-induced hepatic steatosis. Methods: Male Bim/Bid wild type (WT) and double knockout (dko) mice were fed a high-fat diet (HFD; 60% kilocalories from fat; D12492, Research Diets) ad libitum. After 5 weeks, each animal underwent 60 minutes of 70% warm hepatic ischemia followed by 6 hours of reperfusion. Animals were then sacrificed to collect serum and hepatic tissue for transaminase and triglyceride (TG) content, respectively. Lean controls fed standard chow provided baselines to assess for the development of steatosis and its effect on IRI in both WT and dko mice. Data were analyzed using student’s t-test and reported as mean 6SEM. P value 0.05 was considered significant. Results: Following 5 weeks of HFD, both groups had increased hepatic TG levels (WT: 59.5 69.1 mg/mg protein; dko: 61.9 612.8 mg/mg protein) compared to their lean controls (WT: 31.8 61.5 mg/mg protein; dko: 37.2 63.4 mg/mg protein). the difference in the degree of steatosis between WT and dko mice fed HFD was insignificant (p ¼ 0.89). Steatotic WT mice suffered significantly greater IRI compared to their lean counterparts (p ¼ 0.044 and 0.042 for AST and ALT, respectively) Figure 1. Absence of Bim/Bid proteins significantly attenuated IRI in the setting of steatosis (p ¼ 0.031 and 0.028 for AST and ALT, respectively). in steatotic dko mice, IRI was comparable to lean WT mice (p ¼ 0.285 and 0.502 for AST and ALT, respectively). Conclusions: A murine model of hepatic steatosis is inducible through dietary modification. Hepatic steatosis accentuates IRI. in absence of BH3-only proteins, the accentuation of IRI caused by steatosis is mitigated to levels comparable with lean mice. BH3-only proteins are significant mediators of IRI in the setting of steatosis and may represent novel targets for ameliorating IRI.
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neoadjuvant chemoradiation (CRT). Here, our objective was to determine the incidence of specific KRAS gene mutations with concurrent TP53 gene mutations. Methods: Two hundred patients with AJCC Stage I-III rectal cancer from two prospective clinical trials were assessed. Pre-treatment tumor biopsies were obtained via endoscopy during initial clinical evaluation. Tumor DNA was extracted and KRAS and TP53 mutation status was determined by PCR and sequencing. All patients then underwent preoperative chemotherapy followed by radiation; and then followed by surgery. Response was evaluated according to AJCC guidelines. Surgical specimens without residual disease were determined to have a pathologic complete response (pCR). Results: Overall, 107 (53.5%) patients had TP53 gene mutation, and 73 (36.5%) had KRAS gene mutation; 33 (16.5%) patients had concurrent TP53 and KRAS mutation. Patients with concomitant TP53 and KRAS mutations had the lowest pCR rate when compared to patients with single mutations or wild-type TP53 and KRAS genes(9.1% vs. 35.3%; p¼0.002). We then assessed the codon locations of KRAS mutation and discovered that mutations in codon 12 occurred in 49 (24.5%) patients, codon 13 in 14 (7%) patients, and codon 61 in 7 (3.5%) patients. Patients with codon 12 mutations were less likely to have concurrent TP53 gene mutation compared to patients with either KRAS codon 13 or 61 mutations (38.8% vs. 66.6%; p¼0.0211). Conclusions: Our study confirms that tumors with both KRAS and TP53 mutations are less likely to respond to CRT. in addition, our data suggests that tumors with KRAS codon 12 mutation are less likely to occur with TP53 gene mutation. the association of select genetic alterations may affect tumor response to neoadjuvant therapy.
TABLE 1 Correlation of KRAS and TP53 Gene Mutations Factors
Total
Total Population 200 KRAS Status Wild-type 127 Any KRAS Mutation 73 Codon 12 Mutations 49 Codon 13 or 61 21 Mutations
Wild-type TP53 Mutant TP53 N (%) N (%) p-value 93 (46.5%)
107 (53.5%)
53 (41.7%) 40 (54.8%) 30 (61.2%) 7 (33.3)
74 (58.3%) 33 (45.2%) 19 (38.8%) 14 (66.6%)
0.0795 0.0211 0.2504
39.2. Gastrointestinal Cancers in Young Survivors of Lymphoma: Implications for Earlier Screening. L. R. Smith, E. Feliberti, R. Perry; Eastern Virginia Medical School, Norfolk, VA 38.10. Columbian Surgical Society - Unplanned Reoperations in General Surgery: Risk Factors and Outcomes. O. Guevara
ONCOLOGY 5: COLORECTAL 39.1. Detection of KRAS Codon 12 Mutations is not Associated with Concurrent Detection of TP53 Mutations in Patients With Rectal Cancer. M. N. Duldulao, K. Choy, E. M. Ko, K. Carter, W. Lee, W. Li, Z. Chen, J. Kim, J. GarciaAguilar; City of Hope National Medical Center, Duarte, CA Introduction: We have previously shown that rectal cancer patients with both TP53 and KRAS gene mutations are resistant to
Introduction: Survivors of lymphomas are at greater risk for developing various malignancies later in life. This study sought to determine if patients diagnosed under the age of 40 would benefit from earlier screening for gastrointestinal (GI) malignancies. Methods: Analysis of the Surveillance Epidemiology and End Results (SEER) database using data accrued from 1973-2008. Patients younger than 40 years old who were diagnosed with Hodgkin’s (HL) or Non-Hodgkin’s Lymphoma (NHL) between 1973 and 1993 were included. the incidence of various GI cancers in these patients was obtained. Standardized incidence ratios using the SEERStat software were generated to identify more frequent and early age-onset second malignancies in this cohort. Results: In this time period, 27,339 HL patients and 138,474 NHL patients were identified, among whom 8,892 HL and 7,606 NHL patients were less than 40 years old. Their average age and race were similar but there were more males in the NHL group (54% vs 68%). The 5-year survival among HL and NHL
304
ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS
patients younger than 40 was 90% and 65% respectively. In HL patients under 40, the SIR for esophageal (EC), gastric (GC) and colorectal (CRC) cancers were increased at 4.2, 8.5 and 1.9 (all p<0.05), while the corresponding SIR in the NHL group were not increased (1.0, 1.5 and 0.74, respectively, p¼NS). HL patients diagnosed in their teens were at significantly greater risk for all three cancers (SIR 29.5, 22.3, 5.5; p<0.05). The mean age at diagnosis of EC, GC and CRC as a second malignancy were 42, 34 and 44 respectively for patients diagnosed with HL in their teens, and 49, 42 and 47 respectively for those diagnosed with HL in their 20’s. The average latency for patients under 40 between diagnosis of HL and the secondary diagnosis of EC, GC and CRC was 23, 19 and 22 years respectively. Of those in HL group who developed EC, GC and CRC, 60, 76 and 67% received radiation during their initial treatment. Conclusions: Patients who develop and survive HL at a young age develop cancers of the stomach, esophagus and colon/rectum earlier and at a higher rate than the general population. This group of patients may benefit from earlier screening for these cancers.
colony forming assays of untreated and treated cells (0 - 6 Gy IR). Five-wk old athymic female Balb/c nude mice were inoculated with 2X106HT-29 colorectal cancer cells. Once tumors formed, mice were randomized to one of fourtreatments: (1) control, (2) IR [2 Gy X 5], (3) JS-K [20 uM/Kg i.p.], (4) JS-K + IR. Tumor load was measured weekly and at the end of treatment. Mice were sacrificed for final tumor load measurement following treatment. Results: Clonogenic assays demonstrated that HT-29 JS-K treated cells were more sensitive to IR at 4 Gy (SF-4 ¼ 0.35) vs. untreated cells (SF-6 ¼ 0.45) and at 6 Gy (SF-6 ¼ 0.21 vs. 0.29 in treated and untreated cells respectively; Fig. 1B). Following 40 days of treatment there was a 28 fold difference in tumor growth in control mice compared to a 14fold difference in mice receiving JS-K + IR (p < 0.001; Fig. 1C). Conclusions: The nitric oxide donor JS-K demonstrates antitumor activity against rectal cancer in vitro and in vivo. The mechanism of action leading to this response remains to be investigated.
39.3. Effect of Postoperative Complications on Survival of Patients Treated for Rectal Cancer. S. B. Stringfield, G. E. Leverson, E. F. Foley, B. A. Harms, C. P. Heise, G. D. Kennedy; University of Wisconsin Department of Surgery, Madison, WI Introduction: Rectal cancer is a common and lethal disease. Surgical resection after chemoradiation remains the standard of care, and is followed by adjuvant chemotherapy in patients at high risk for recurrence. the rate of complications following surgery for rectal cancer remains unacceptably high. We wanted to evaluate the effect of complications on overall survival. We hypothesized that delay in initiation of chemotherapy following surgery for rectal cancer negatively impacts survival. Methods: From 1995-2010, 301 patients underwent surgical resection of rectal cancer at our institution. A retrospective clinical review was conducted focusing on the timing of chemotherapy following surgery and the factors that delayed or prevented therapy. This data was correlated with cancer-specific survival. Categorical variables were analyzed via the Chi-square test. Multivariable analyses were performed. A p<0.05 was considered significant. Results: Among the 301 patients, 30 were known to have a delay in administration of chemotherapy, defined as >56 days following surgery. Of those delays, 50% were due to surgical complications. at follow-up, patients with a delay in chemotherapy were significantly more likely to be deceased from rectal cancer as compared to patients who did not have a delay in administration (48% v 16% mortality, p<0.0018). Conclusions: Delays in initiation of chemotherapy following surgical resection of rectal cancer can have a significant impact on cancer-specific mortality. The most common cause of delay is due to surgical complications. Decreases in rates of surgical complications could have an impact on survival.
39.4. Radiosensitization of Colorectal HT-29 Cells and Xenografts by the Nitric Oxide Donor JS-K. S. Huerta, X. Gao; University of Texas Southwestern Medical Center, Dallas, TX Introduction: HT-29 colorectal cancer cells are highly resistant to ionizing radiation. Nitric oxide (NO) donors have demonstrated substantial radiosensitizing activity against colorectal cancer in vitro and in vivo. JS-K (Fig. 1A) is an NO donor that releases 1.7 moles of NO in the presence of glutathione (GSH). JS-K seems to have selective cytotoxicity against cancer cells. In the present report, we evaluated the activity of JS-K in vitro and in vivo against HT-29 colorectal cancer cells. Methods: HT-29 cell survival was assessed by
39.5. Deletion of P38-alpha MAPK Within Enterocytes Promotes Colon Tumorigenesis. D. Wakeman, J. E. Schneider, J. Liu, W. S. Wandu, J. Guo, C. R. Erwin, T. S. Stappenbeck, B. W. Warner; Washington University School of Medicine, St. Louis, MO Introduction: Colorectal cancer is the second leading cause of cancer-related death in the United States. p38-alpha MAPK (p38) is a tumor suppressor known to be mutated in human cancers, but its specific role in colorectal cancer is not completely understood. in some studies, p38 inhibits enterocyte proliferation and activates apoptosis in the intestine. Therefore, we sought to test the hypothesis that intestinal disruption of p38 would lead to increased tumorigenesis in the colon. Methods: p38 was deleted in mice specifically in the intestinal mucosa using a tamoxifen-inducible Cre system under control of the villin promoter. An azoxymethane (AOM) and dextran sodium sulfate (DSS) protocol was used to drive tumor development. Four groups of mice were studied: wild type (WT) mice given water, WT mice given DSS (WT DSS), p38-null mice given water, and p38-null mice administered DSS (KO DSS). Tumor measurements were made from photographs of colons removed at sacrifice using computer software. Results: Both WT and p38-null mice developed tumors after treatment with AOM and DSS. While WT DSS (7 of 14) were statistically just as likely as the KO DSS (9 of 11) mice to develop colonic tumors (p¼.2), the KO DSS group had significantly more tumors (1.1 +/- 0.4 colonic tumor per mouse vs 3.7 +/- 0.9, p¼.008). KO DSS mice had nearly four-times the total tumor burden as WT DSS mice (4.8 +/- 1.8 cm2 of colonic tumors vs 17.4 ¼/- 5.6, p¼.03). WT DSS and KO DSS groups had a similar degree of colon inflammation. Conclusions: Deletion of p38-alpha MAPK within the colonic mucosa leads to a hyperplastic state promoting greater tumor development. Since the severity of colitis was not augmented in mice with p38 deficiency, tumor development is likely mediated by impaired cell cycle regulation within the colonic epithelium. Manipulation of p38-alpha MAPK activity may provide a novel treatment and/or prevention strategy in the management of colorectal cancer.
303
neoadjuvant chemoradiation (CRT). Here, our objective was to determine the incidence of specific KRAS gene mutations with concurrent TP53 gene mutations. Methods: Two hundred patients with AJCC Stage I-III rectal cancer from two prospective clinical trials were assessed. Pre-treatment tumor biopsies were obtained via endoscopy during initial clinical evaluation. Tumor DNA was extracted and KRAS and TP53 mutation status was determined by PCR and sequencing. All patients then underwent preoperative chemotherapy followed by radiation; and then followed by surgery. Response was evaluated according to AJCC guidelines. Surgical specimens without residual disease were determined to have a pathologic complete response (pCR). Results: Overall, 107 (53.5%) patients had TP53 gene mutation, and 73 (36.5%) had KRAS gene mutation; 33 (16.5%) patients had concurrent TP53 and KRAS mutation. Patients with concomitant TP53 and KRAS mutations had the lowest pCR rate when compared to patients with single mutations or wild-type TP53 and KRAS genes(9.1% vs. 35.3%; p¼0.002). We then assessed the codon locations of KRAS mutation and discovered that mutations in codon 12 occurred in 49 (24.5%) patients, codon 13 in 14 (7%) patients, and codon 61 in 7 (3.5%) patients. Patients with codon 12 mutations were less likely to have concurrent TP53 gene mutation compared to patients with either KRAS codon 13 or 61 mutations (38.8% vs. 66.6%; p¼0.0211). Conclusions: Our study confirms that tumors with both KRAS and TP53 mutations are less likely to respond to CRT. in addition, our data suggests that tumors with KRAS codon 12 mutation are less likely to occur with TP53 gene mutation. the association of select genetic alterations may affect tumor response to neoadjuvant therapy.
TABLE 1 Correlation of KRAS and TP53 Gene Mutations Factors
Total
Total Population 200 KRAS Status Wild-type 127 Any KRAS Mutation 73 Codon 12 Mutations 49 Codon 13 or 61 21 Mutations
Wild-type TP53 Mutant TP53 N (%) N (%) p-value 93 (46.5%)
107 (53.5%)
53 (41.7%) 40 (54.8%) 30 (61.2%) 7 (33.3)
74 (58.3%) 33 (45.2%) 19 (38.8%) 14 (66.6%)
0.0795 0.0211 0.2504
39.2. Gastrointestinal Cancers in Young Survivors of Lymphoma: Implications for Earlier Screening. L. R. Smith, E. Feliberti, R. Perry; Eastern Virginia Medical School, Norfolk, VA 38.10. Columbian Surgical Society - Unplanned Reoperations in General Surgery: Risk Factors and Outcomes. O. Guevara
ONCOLOGY 5: COLORECTAL 39.1. Detection of KRAS Codon 12 Mutations is not Associated with Concurrent Detection of TP53 Mutations in Patients With Rectal Cancer. M. N. Duldulao, K. Choy, E. M. Ko, K. Carter, W. Lee, W. Li, Z. Chen, J. Kim, J. GarciaAguilar; City of Hope National Medical Center, Duarte, CA Introduction: We have previously shown that rectal cancer patients with both TP53 and KRAS gene mutations are resistant to
Introduction: Survivors of lymphomas are at greater risk for developing various malignancies later in life. This study sought to determine if patients diagnosed under the age of 40 would benefit from earlier screening for gastrointestinal (GI) malignancies. Methods: Analysis of the Surveillance Epidemiology and End Results (SEER) database using data accrued from 1973-2008. Patients younger than 40 years old who were diagnosed with Hodgkin’s (HL) or Non-Hodgkin’s Lymphoma (NHL) between 1973 and 1993 were included. the incidence of various GI cancers in these patients was obtained. Standardized incidence ratios using the SEERStat software were generated to identify more frequent and early age-onset second malignancies in this cohort. Results: In this time period, 27,339 HL patients and 138,474 NHL patients were identified, among whom 8,892 HL and 7,606 NHL patients were less than 40 years old. Their average age and race were similar but there were more males in the NHL group (54% vs 68%). The 5-year survival among HL and NHL
304
ASSOCIATION FOR ACADEMIC SURGERY AND SOCIETY OF UNIVERSITY SURGEONS—ABSTRACTS
patients younger than 40 was 90% and 65% respectively. In HL patients under 40, the SIR for esophageal (EC), gastric (GC) and colorectal (CRC) cancers were increased at 4.2, 8.5 and 1.9 (all p<0.05), while the corresponding SIR in the NHL group were not increased (1.0, 1.5 and 0.74, respectively, p¼NS). HL patients diagnosed in their teens were at significantly greater risk for all three cancers (SIR 29.5, 22.3, 5.5; p<0.05). The mean age at diagnosis of EC, GC and CRC as a second malignancy were 42, 34 and 44 respectively for patients diagnosed with HL in their teens, and 49, 42 and 47 respectively for those diagnosed with HL in their 20’s. The average latency for patients under 40 between diagnosis of HL and the secondary diagnosis of EC, GC and CRC was 23, 19 and 22 years respectively. Of those in HL group who developed EC, GC and CRC, 60, 76 and 67% received radiation during their initial treatment. Conclusions: Patients who develop and survive HL at a young age develop cancers of the stomach, esophagus and colon/rectum earlier and at a higher rate than the general population. This group of patients may benefit from earlier screening for these cancers.
colony forming assays of untreated and treated cells (0 - 6 Gy IR). Five-wk old athymic female Balb/c nude mice were inoculated with 2X106HT-29 colorectal cancer cells. Once tumors formed, mice were randomized to one of fourtreatments: (1) control, (2) IR [2 Gy X 5], (3) JS-K [20 uM/Kg i.p.], (4) JS-K + IR. Tumor load was measured weekly and at the end of treatment. Mice were sacrificed for final tumor load measurement following treatment. Results: Clonogenic assays demonstrated that HT-29 JS-K treated cells were more sensitive to IR at 4 Gy (SF-4 ¼ 0.35) vs. untreated cells (SF-6 ¼ 0.45) and at 6 Gy (SF-6 ¼ 0.21 vs. 0.29 in treated and untreated cells respectively; Fig. 1B). Following 40 days of treatment there was a 28 fold difference in tumor growth in control mice compared to a 14fold difference in mice receiving JS-K + IR (p < 0.001; Fig. 1C). Conclusions: The nitric oxide donor JS-K demonstrates antitumor activity against rectal cancer in vitro and in vivo. The mechanism of action leading to this response remains to be investigated.
39.3. Effect of Postoperative Complications on Survival of Patients Treated for Rectal Cancer. S. B. Stringfield, G. E. Leverson, E. F. Foley, B. A. Harms, C. P. Heise, G. D. Kennedy; University of Wisconsin Department of Surgery, Madison, WI Introduction: Rectal cancer is a common and lethal disease. Surgical resection after chemoradiation remains the standard of care, and is followed by adjuvant chemotherapy in patients at high risk for recurrence. the rate of complications following surgery for rectal cancer remains unacceptably high. We wanted to evaluate the effect of complications on overall survival. We hypothesized that delay in initiation of chemotherapy following surgery for rectal cancer negatively impacts survival. Methods: From 1995-2010, 301 patients underwent surgical resection of rectal cancer at our institution. A retrospective clinical review was conducted focusing on the timing of chemotherapy following surgery and the factors that delayed or prevented therapy. This data was correlated with cancer-specific survival. Categorical variables were analyzed via the Chi-square test. Multivariable analyses were performed. A p<0.05 was considered significant. Results: Among the 301 patients, 30 were known to have a delay in administration of chemotherapy, defined as >56 days following surgery. Of those delays, 50% were due to surgical complications. at follow-up, patients with a delay in chemotherapy were significantly more likely to be deceased from rectal cancer as compared to patients who did not have a delay in administration (48% v 16% mortality, p<0.0018). Conclusions: Delays in initiation of chemotherapy following surgical resection of rectal cancer can have a significant impact on cancer-specific mortality. The most common cause of delay is due to surgical complications. Decreases in rates of surgical complications could have an impact on survival.
39.4. Radiosensitization of Colorectal HT-29 Cells and Xenografts by the Nitric Oxide Donor JS-K. S. Huerta, X. Gao; University of Texas Southwestern Medical Center, Dallas, TX Introduction: HT-29 colorectal cancer cells are highly resistant to ionizing radiation. Nitric oxide (NO) donors have demonstrated substantial radiosensitizing activity against colorectal cancer in vitro and in vivo. JS-K (Fig. 1A) is an NO donor that releases 1.7 moles of NO in the presence of glutathione (GSH). JS-K seems to have selective cytotoxicity against cancer cells. In the present report, we evaluated the activity of JS-K in vitro and in vivo against HT-29 colorectal cancer cells. Methods: HT-29 cell survival was assessed by
39.5. Deletion of P38-alpha MAPK Within Enterocytes Promotes Colon Tumorigenesis. D. Wakeman, J. E. Schneider, J. Liu, W. S. Wandu, J. Guo, C. R. Erwin, T. S. Stappenbeck, B. W. Warner; Washington University School of Medicine, St. Louis, MO Introduction: Colorectal cancer is the second leading cause of cancer-related death in the United States. p38-alpha MAPK (p38) is a tumor suppressor known to be mutated in human cancers, but its specific role in colorectal cancer is not completely understood. in some studies, p38 inhibits enterocyte proliferation and activates apoptosis in the intestine. Therefore, we sought to test the hypothesis that intestinal disruption of p38 would lead to increased tumorigenesis in the colon. Methods: p38 was deleted in mice specifically in the intestinal mucosa using a tamoxifen-inducible Cre system under control of the villin promoter. An azoxymethane (AOM) and dextran sodium sulfate (DSS) protocol was used to drive tumor development. Four groups of mice were studied: wild type (WT) mice given water, WT mice given DSS (WT DSS), p38-null mice given water, and p38-null mice administered DSS (KO DSS). Tumor measurements were made from photographs of colons removed at sacrifice using computer software. Results: Both WT and p38-null mice developed tumors after treatment with AOM and DSS. While WT DSS (7 of 14) were statistically just as likely as the KO DSS (9 of 11) mice to develop colonic tumors (p¼.2), the KO DSS group had significantly more tumors (1.1 +/- 0.4 colonic tumor per mouse vs 3.7 +/- 0.9, p¼.008). KO DSS mice had nearly four-times the total tumor burden as WT DSS mice (4.8 +/- 1.8 cm2 of colonic tumors vs 17.4 ¼/- 5.6, p¼.03). WT DSS and KO DSS groups had a similar degree of colon inflammation. Conclusions: Deletion of p38-alpha MAPK within the colonic mucosa leads to a hyperplastic state promoting greater tumor development. Since the severity of colitis was not augmented in mice with p38 deficiency, tumor development is likely mediated by impaired cell cycle regulation within the colonic epithelium. Manipulation of p38-alpha MAPK activity may provide a novel treatment and/or prevention strategy in the management of colorectal cancer.