Radiation therapy for retroperitoneal sarcoma

Retroperitoneal soft-tissue sarcoma is an uncommon cancer of mesodermal origin, which is difficult to treat owing to its location and proximity to vital structures. Complete gross resection, often involving en bloc resection, is the standard of care as it represents the only treatment that improves overall survival. Unlike extremity sarcoma, retroperitoneal soft-tissue sarcoma tumor mortality is from local recurrence. Radiation therapy is the only adjuvant treatment that has improved local control in several institutional series. However, there remains no definitive prospective, randomized trial that establishes the role of adjuvant radiation versus no radiation. Owing to significant radiation morbidity with adjacent organs, especially the small bowel, there exists no consensus on radiation timing, delivery method or dosing. Recent and current protocols use preoperative external-beam radiation with or without a method of focal boost dosing. Methods of boost dosing include brachytherapy, intraoperative radiation therapy and intensity-modulated radiation therapy. Further studies are needed to definitively include radiation therapy in the standard treatment of retroperitoneal soft-tissue sarcoma and to find the optimal balance between acceptable radiation toxicity and effective local control in treatment protocols.

Abstract 2446: The effects of dacomitinib (PF-299) on pancreatic ductal adenocarcinoma (PDAC) and cancer-associated fibroblasts (CAFs)

Background: PF-299 is an oral irreversible small molecule that is an effective inhibitor of the ErbB pathway, which has been shown to play a critical role in pancreatic ductal adenocarcinoma (PDAC) pathogenesis. Indirect activation of Epidermal Growth Factor Receptor (EGFR) signaling through ErbB3 heterodimerization and stromal ligand production has been shown to act as an escape mechanism for EGFR directed therapies. This phenomenon may explain the modest clinical benefit of anti-EGFR drugs in PDAC. We have previously shown that CAFs are responsible for the secretion of ErbB pathway ligands. The addition of CAFs to PDAC xenografts improves the tumor modeling and adds testing stringency to novel targeted therapies. We hypothesize that PF-299 inhibition of multiple ErbB receptors results in effective inhibition of PDAC tumor progression.

Materials: AsPC-1, BxPC-3, C3, Panc-1 and Panc-1+ErbB3 (stable ErbB3 transfected cell line) PDAC cells were treated with different concentrations of PF-299. PDAC cell proliferation and ErbB signaling was analyzed in vitro. Subcutaneous xenografts were developed using the AsPC-1 and BxPC-3 cell lines alone and in combination with CAFs. CAFs were obtained from surgically resected PDAC tissue. Xenografts were analyzed for tumor growth and tumor-associated ErbB signaling after treatment with PF-299.

Results: In vitro, PF-299 effectively inhibited AsPC-1, BxPC-3, C3, Panc-1 and Panc-1+ErbB3 cell proliferation in a dose-dependent manner (1-10 μM). PF-299 decreased migration of AsPC-1 cells by 54%, while the addition of CAFs (in co-culture) increased cell migration by 13% in the PF-299 treated group compared to an increase of 273% in the control group. In vivo, tumor proliferation of AsPC-1 and BxPC-3 xenografts was significantly inhibited by PF-299 treatment (p=0.04 and p=0.002, respectively). Combination of AsPC-1/BxPC-3+CAFs xenografts increased initial tumor size by 22.5% (p=0.17) for the AsPC-1 cell line and by 11.6% (p=0.46) for the BxPC-3 cell line compared to cells without CAFs. The AsPC-1+CAFs PF-299 treated tumors were 4.1% smaller than placebo treated tumors (p=0.99), while BxPC-3+CAFs PF-299 treated tumor were 26% smaller than the placebo treated group (p=0.05). Immunoblot analysis of AsPC-1/BxPC-3+CAFs xenografts confirmed PF-299 mediated inhibition of both EGFR and ErbB3 mediated signaling.

Conclusion: We demonstrated that PF-299 targets multiple ErbB receptors, including ErbB3. PF-299 significantly inhibited PDAC cell proliferation, migration and tumor progression by targeting EGFR and ErbB3 signaling. CAFs may provide a novel addition to current models by increasing tumor virulence while pan-ErbB receptor targeting may improve therapeutic approaches to PDAC.

Citation Format: Brett L. Broussard, Alevtina Mikhaylina, Juan P. Arnoletti, Martin J. Heslin, Andrey Frolov. The effects of dacomitinib (PF-299) on pancreatic ductal adenocarcinoma (PDAC) and cancer-associated fibroblasts (CAFs). [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2446. doi:10.1158/1538-7445.AM2013-2446

Endoscopic ultrasound evaluation in the surgical treatment of duodenal and peri-ampullary adenomas

AIM: To investigate endoscopic ultrasound (EUS) for predicting depth of mucosal invasion and to analyze outcomes following endoscopic and transduodenal resection.

METHODS: Records of 111 patients seen at our institution from November 1999 to July 2011 with the post-operative pathological diagnosis of benign ampullary and duodenal adenomas were reviewed. Records of patients who underwent preoperative EUS for diagnostic purposes were identified. The accuracy of EUS in predicting the absence of muscular invasion was assessed by comparing EUS reports to the final surgical pathological results. In addition, the incidence of the post-operative complications over a period of 30 d and the subsequent long-term outcome (recurrence) over a period of 30 mo associated with endoscopic and transduodenal surgical resection was recorded, compared and analyzed.

RESULTS: Among 111 patients with benign ampullary and duodenal adenomas, 47 underwent preoperative EUS for 29 peri-ampullary lesions and 18 duodenal lesions. In addition, computed tomography was performed in 18 patients, endoscopic retrograde cholangio-pancreatography in 10 patients and esophagogastroduodenoscopy in 22 patients. There were 43 patients with sporadic adenomas and 4 patients with familial adenomatous polyposis (FAP)/other polyposis syndromes. In 38 (81%, P < 0.05) patients, EUS reliably identified absence of submucosal and muscularis invasion. In 4 cases, EUS underestimated submucosal invasion that was proven by pathology. In the other 5 patients, EUS predicted muscularis invasion which could not be demonstrated in the resected specimen. EUS predicted tumor muscularis invasion with a specificity of 88% and negative predictive value of 90% (P < 0.05). Types of resection performed included endoscopic resection in 22 cases, partial duodenectomy in 9 cases, transduodenal ampullectomy with sphincteroplasty in 10 cases and pancreaticoduodenectomy in 6 cases. The main post-operative final pathological results included villous adenoma (n = 5), adenoma (n = 8), tubulovillous adenoma (n = 10), tubular adenoma (n = 20) and hyperplastic polyp (n = 2). Among the 47 patients who underwent resection, 8 (17%, 5 of which corresponded to surgical resection) developed post-procedural complications which included retroperitoneal hematoma, intra-abdominal abscess, wound infection, delayed gastric emptying and prolonged ileus. After median follow-up of 20 mo there were 6 local recurrences (13%, median follow-up = 20 mo) 4 of which were in patients with FAP.

CONCLUSION: EUS accurately predicts the depth of mucosal invasion in suspected benign ampullary and duodenal adenomas. These patients can safely undergo endoscopic or local resection.

Soft tissue sarcoma, version 2.2012: featured updates to the NCCN guidelines

The major changes to the 2012 and 2011 NCCN Guidelines for Soft Tissue Sarcoma pertain to the management of patients with gastrointestinal stromal tumors (GISTs) and desmoid tumors (aggressive fibromatosis). Postoperative imatinib following complete resection for primary GIST with no preoperative imatinib is now included as a category 1 recommendation for patients with intermediate or high risk of recurrence. The panel also reaffirmed the recommendation for preoperative use of imatinib in patients with GISTs that are resectable with negative margins but associated with significant surgical morbidity. Observation was included as an option for patients with resectable desmoid tumors that are small and asymptomatic, not causing morbidity, pain, or functional limitation. Sorafenib is included as an option for systemic therapy for patients with desmoid tumors.

Neuroendocrine tumors

Neuroendocrine tumors comprise a broad family of tumors, the most common of which are carcinoid and pancreatic neuroendocrine tumors. The NCCN Neuroendocrine Tumors Guidelines discuss the diagnosis and management of both sporadic and hereditary neuroendocrine tumors. Most of the recommendations pertain to well-differentiated, low- to intermediate-grade tumors. This updated version of the NCCN Guidelines includes a new section on pathology for diagnosis and reporting and revised recommendations for the surgical management of neuroendocrine tumors of the pancreas.

By the pricking of my thumbs, something wicked this way comes: sporadic cancers versus eponymous hereditary cancer predisposition syndromes

Advances in cancer genomics have led to the recognition of a growing number of high-penetrance single-gene cancer predisposition syndromes. Frequently, the suspicion for a hereditary syndrome is raised by a strongly positive family history. However, other features, such as younger-than-usual age at diagnosis and rare histology should also prompt consideration of a genetic syndrome. Common malignancies frequently show a positive family history without an eponymous syndrome being recognized. This article reports on a case with an unusual constellation of malignancies with distinctive pathologies, which raised suspicion for an eponymous cancer pre-disposition syndrome. Absent a positive family history, a de novo mutation-an alteration in a gene that is present for the first time in a family member as a result of a mutation in a germ cell of one of the parents or in the fertilized ovum-was suspected. The authors discuss indications for genetic counseling and testing, limitations, and the evidence that supports the recommendations as formulated by working groups and the NCCN. Most frequently, these recommendations are reasonable statements based on the natural history of the disease, but without population-based studies for many rare syndromes, the actual penetrance, variable expressivity, and actual associated cancer risk are unknown.

Targeting ErbB3-mediated stromal-epithelial interactions in pancreatic ductal adenocarcinoma

Background:

We sought to investigate the role of ErbB3-mediated signalling on the interaction between pancreatic cancer-associated fibroblasts (CAF) and carcinoma cells in an effort to disrupt tumourigenic pancreatic ductal adenocarcinoma (PDAC) stromal–epithelial cross-communication.

Methods:

Primary CAF cultures were established from human PDAC surgical specimens. AsPC-1 pancreatic cancer cell murine subcutaneous xenografts were developed in the presence and absence of CAF and were subsequently treated with epidermal growth factor receptor (EGFR) inhibitors (erlotinib) and ErbB3 inhibitors (MM-121, monoclonal ErbB3 antibody).

Results:

Cancer-associated fibroblasts were found to secrete neuregulin-1 (NRG-1), which promoted proliferation via phosphorylation of ErbB3 and AKT in AsPC-1 PDAC cells. This signalling cascade was effectively inhibited both in vitro and in vivo by specific ErbB3 blockade with MM-121, with greater degree of tumourigenesis inhibition when combined with erlotinib. The CAF–AsPC-1 pancreatic cancer xenografts reached significantly greater tumour volume than those xenografts lacking CAF and were resistant to the anti-tumour effects of EGFR inhibition with erlotinib.

Conclusion:

Cancer-associated fibroblasts-derived NRG-1 promote PDAC tumourigenesis via ErbB3-AKT signalling and overcomes single-agent EGFR inhibition. Disruption of this stromally mediated tumourigenic mechanism is best obtained through combined EGFR-ErbB3 inhibition with both erlotinib and MM-121. We have identified the NRG-1/ErbB3 axis as an attractive molecular target for the interruption of tumourigenic stromal–epithelial interactions within the PDAC microenvironment.

ErbB3 expression promotes tumorigenesis in pancreatic adenocarcinoma

Historically, ErbB3 has been overlooked within the ErbB receptor family due to its perceived lack of tyrosine kinase activity. We have previously demonstrated that in pancreatic cancer ErbB3 is the preferred dimerization partner of EGFR, ErbB3 protein expression level directly correlates with the anti-proliferative effect of erlotinib (an EGFR-specific tyrosine kinase inhibitor), and transient knockdown of ErbB3 expression results in acquired resistance to EGFR-targeted therapy. In this study, we develop a stable isogenic model of ErbB3 expression in an attempt to decipher ErbB3's true contribution to pancreatic cancer tumorigenesis and to examine how this receptor affects cellular sensitivity to EGFR-targeted therapy. Analysis of the EGFR-ErbB3 heterodimer demonstrates that ligand-induced PI3K-AKT signaling is limited to ErbB3-expressing cells and that this signaling cascade can be partially abrogated by inhibiting EGFR function with erlotinib. Using our model of exogenous ErbB3 expression we showed a direct relationship between ErbB3 protein levels and increased pancreatic cancer cell proliferation in vitro. In vivo, ErbB3(+)PANC-1 xenografts had a significantly larger tumor volume than PANC-1 control xenografts (ErbB3-PANC-1) and displayed increased sensitivity to EGFR-targeted therapy. In pancreatic cancer, ErbB3 appears to be critically involved in EGFR signaling as evidenced by its profound effect on cellular proliferation and its ability to influence response to EGFR-targeted therapy.

Epidermal growth factor receptor (EGFR) intron 1 polymorphism and clinical outcome in pancreatic adenocarcinoma

BACKGROUND

Epidermal growth factor receptor (EGFR) intron 1 has a polymorphic region of CA repeats that is believed to be associated with increased EGFR expression, tumor aggressiveness, and worse survival in cancer patients.

METHODS

A large population of pancreatic adenocarcinoma patients was investigated to evaluate this polymorphism as a potential prognostic marker of clinical outcome. Deoxyribonucleic acid obtained from 50 resected pancreatic adenocarcinomas and from 85 diagnostic endoscopic ultrasound-guided fine-needle aspiration procedures corresponding to patients with unresectable tumors was included. The correlation between CA repeat length and EGFR messenger ribonucleic acid levels was also examined.

RESULTS

Analysis of the 135 patients revealed no correlation between EGFR intron 1 CA repeat length and tumor stage. There was no difference in overall patient survival when stratified by allele length. A correlation between EGFR intron 1 length and EGFR transcript and protein levels could not be established.

CONCLUSIONS

The length of the EGFR intron 1 CA repeats does not correlate with levels of EGFR expression and cannot be used as marker of clinical prognosis in pancreatic cancer patients.

Abstract 1171: Gastrointestinal stromal tumors (GIST) cell proliferation inhibition with combined adenoviral and molecular targeted therapy

Introduction: GIST, the most common mesenchymal malignancies of the GI tract, are characterized by gain-of-function mutations in KIT and PDGFRα receptors. Imatinib and sunitinib are tyrosine kinase inhibitors (TKI) currently approved for the treatment of GIST. Recent evidence suggests that GIST cells acquire secondary resistance to TKI through activation of alternative signaling pathways. We hypothesize that gene therapy with replicative vector oncolysis (virotherapy) can be utilized to improve efficacy of TKI and overcome GIST resistance to treatment.

Objectives: To determine if a panel of oncolytic adenoviruses in combination with imatinib and sunitinib, results in synergistic inhibition of GIST cell proliferation.

Results: GIST882 and GIST-T1 cells were subjected to imatinib and sunitinib treatment in combination with a panel of oncolytic adenoviruses (Ad5, Ad5RGD, Ad5pK7, and Ad5 - Ad3 fiber knob), to assess their inhibitory effects on cell proliferation. The Ad5/3 vector had the best rate of gene transfer and cytolytic effect. The greatest anti-proliferative effects were observed with 100 viral particles/cell of the Ad5/3 vector combined with TKI concentrations of 0.1 µM in GIST-T1 cell line. The combination of TKI and oncolytic adenoviruses showed greater inhibition of GIST cell proliferation (78% decrease) when compared to TKI alone (58% decrease) and viral therapy alone (23% decrease, p&lt;0.01). Successful ex vivo infection and oncolysis of GIST by Ad5/3 particles was confirmed in cells obtained from patient surgical specimens (n=4).

Conclusions: The oncolytic adenovirus Ad5/3 infects and inhibits GIST cell proliferation both in vitro and ex vivo. Virotherapy with Ad5/3 has synergistic anti-proliferative effects with TKI and may help overcome GIST resistance to KIT targeted therapy.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 1171.

Laparoscopic and open distal pancreatectomy: a comparison of outcomes

Laparoscopic (lap) pancreatic surgery has been increasingly reported since its introduction in 1992. A retrospective analysis of consecutive patients undergoing elective lap and open distal pancreatectomy from 2002 to 2007 was performed. Univariate analysis was completed to evaluate perioperative variables. Logistic regression analysis was used to model predictors of postoperative pancreatic fistula. One hundred forty-eight subjects underwent distal pancreatectomy; 98 completed open, 44 lap, and six converted to open. There was no significant difference in the incidence of postoperative morbidity or mortality between the surgical approaches. Decreased operative time (156 vs 200 minutes, P < 0.01), blood loss (157 vs 719 mL, P < 0.01), and length of stay (5.9 vs 8.6 days, P < 0.01) were seen in the lap group. There was no significant difference in the rate of all pancreatic fistula formation (50 vs 46%, P = 0.94) or clinically significant leaks (18 vs 19%, P = 0.97) between techniques. A preoperative biopsy-proven cancer, increasing body mass index, history of pancreatitis, and male gender were significant predictors of having a pancreatic fistula. Lap and open distal pancreatectomy are performed safely at high-volume pancreatic surgery centers. This report provides ongoing support of the feasibility and safety of the lap approach with improved perioperative outcomes and equivalent pancreatic fistula rate.

Laparoscopic and Open Distal Pancreatectomy: A Comparison of Outcomes

Laparoscopic (lap) pancreatic surgery has been increasingly reported since its introduction in 1992. A retrospective analysis of consecutive patients undergoing elective lap and open distal pancreatectomy from 2002 to 2007 was performed. Univariate analysis was completed to evaluate perioperative variables. Logistic regression analysis was used to model predictors of postoperative pancreatic fistula. One hundred forty-eight subjects underwent distal pancreatectomy; 98 completed open, 44 lap, and six converted to open. There was no significant difference in the incidence of postoperative morbidity or mortality between the surgical approaches. Decreased operative time (156 vs 200 minutes, P < 0.01), blood loss (157 vs 719 mL, P < 0.01), and length of stay (5.9 vs 8.6 days, P < 0.01) were seen in the lap group. There was no significant difference in the rate of all pancreatic fistula formation (50 vs 46%, P = 0.94) or clinically significant leaks (18 vs 19%, P = 0.97) between techniques. A preoperative biopsy-proven cancer, increasing body mass index, history of pancreatitis, and male gender were significant predictors of having a pancreatic fistula. Lap and open distal pancreatectomy are performed safely at high-volume pancreatic surgery centers. This report provides ongoing support of the feasibility and safety of the lap approach with improved perioperative outcomes and equivalent pancreatic fistula rate.

Radiofrequency ablation for unresectable tumors of the liver

Surgical resection of primary or metastatic tumors of the liver offers patients the best long-term survival. Liver resections may not be appropriate in patients with bilobar metastases, liver dysfunction, or severe comorbidities. Radiofrequency ablation (RFA) is a technique used to destroy unresectable hepatic tumors through thermocoagulation. We retrospectively reviewed a consecutive series of patients undergoing RFA with unresectable hepatic tumors for local recurrence and overall survival. Under an Institutional Review Board-approved protocol, all patients treated with RFA at the University of Alabama at Birmingham from September 1, 1998, to June 15, 2005, were identified. During this time period, 189 lesions in 107 patients were treated with RFA. Patients' charts were retrospectively reviewed. Data is presented as mean +/- SEM. Significance is defined as P < 0.05. Patient demographics revealed 62 per cent males and 38 per cent females with a mean age of 59 (+/- 1) years. Hepatocellular carcinoma (HCC) represented 54 per cent of the tumors treated. Metastatic colorectal cancer represented 22 per cent and the remaining 24 per cent were other metastatic tumors. Overall recurrence rates for all tumors after RFA was 53 per cent. Local recurrence rates for HCC, colorectal cancer, and other metastatic lesions were 27.6 per cent, 29.1 per cent, and 52 per cent, respectively. The morbidity rate for the procedure was 11 per cent. There was one mortality (0.9%) related to RFA. Laparoscopic RFA for HCC in Childs-Pugh Class C cirrhotics (n = 6) resulted in 50 per cent of patients being transplanted with no evidence of disease at a mean follow-up period of 14 months. RFA is a safe and effective way for treating HCC and other unresectable tumors in the liver that are not eligible for hepatic resection. More effective control of systemic recurrence will dictate survival in the majority of patients with metastatic cancers. Local ablation for HCC in cirrhotic patients may be an effective bridge to transplantation. Liver transplantation may still be the most effective long-term treatment for localized HCC.

Radiofrequency Ablation for Unresectable Tumors of the Liver

Surgical resection of primary or metastatic tumors of the liver offers patients the best long-term survival. Liver resections may not be appropriate in patients with bilobar metastases, liver dysfunction, or severe comorbidities. Radiofrequency ablation (RFA) is a technique used to destroy unresectable hepatic tumors through thermocoagulation. We retrospectively reviewed a consecutive series of patients undergoing RFA with unresectable hepatic tumors for local recurrence and overall survival. Under an Institutional Review Board-approved protocol, all patients treated with RFA at the University of Alabama at Birmingham from September 1, 1998, to June 15, 2005, were identified. During this time period, 189 lesions in 107 patients were treated with RFA. Patients’ charts were retrospectively reviewed. Data is presented as mean ± SEM. Significance is defined as P < 0.05. Patient demographics revealed 62 per cent males and 38 per cent females with a mean age of 59 (±1) years. Hepatocellular carcinoma (HCC) represented 54 per cent of the tumors treated. Metastatic colorectal cancer represented 22 per cent and the remaining 24 per cent were other metastatic tumors. Overall recurrence rates for all tumors after RFA was 53 per cent. Local recurrence rates for HCC, colorectal cancer, and other metastatic lesions were 27.6 per cent, 29.1 per cent, and 52 per cent, respectively. The morbidity rate for the procedure was 11 per cent. There was one mortality (0.9%) related to RFA. Laparoscopic RFA for HCC in Childs-Pugh Class C cirrhotics (n = 6) resulted in 50 per cent of patients being transplanted with no evidence of disease at a mean follow-up period of 14 months. RFA is a safe and effective way for treating HCC and other unresectable tumors in the liver that are not eligible for hepatic resection. More effective control of systemic recurrence will dictate survival in the majority of patients with metastatic cancers. Local ablation for HCC in cirrhotic patients may be an effective bridge to transplantation. Liver transplantation may still be the most effective long-term treatment for localized HCC.

Durable improvements in efficiency, safety, and satisfaction in the operating room

BACKGROUND

Enhanced productivity and efficiency in the operating room must be balanced with patient safety and staff satisfaction. In December 2004, transition to an expanded replacement hospital resulted in mandatory overtime, unpredictable work hours, and poor morale among operating room (OR) staff. A staff-retention crisis resulted, which threatened the viability of the OR and the institution. We report the changes implemented to efficiently deliver safe patient care in a supportive environment for surgeons and OR staff.

STUDY DESIGN

University of Alabama at Birmingham University Hospital OR data were evaluated for fiscal year 2004 and compared with fiscal years 2005 and 2006. Case volumes, number of operational ORs, and on-time case starts were evaluated. OR adverse events were tabulated. Percentage of registered nurse hires and staff departures served as a proxy for staff satisfaction.

RESULTS

Short, intermediate, and longterm strategies were implemented by an engaged OR management committee with the guidance of surgical, anesthesia, and hospital leadership. These included new block time release policies; use of traveling nurses until new staff could be hired and trained; and incentive-based, voluntary, employee-scheduled overtime. Mandatory nursing education time was blocked weekly. Enforcement of the National Patient Safety Goals were implemented and adjudicated with a "surgeon-of-the-day" system providing backup for nurse management. We demonstrated an increase in operations per year, on-time starts, and registered nurse hires in fiscal years 2005 and 2006. During this same time, we were able to markedly decrease the number of adverse events, admitting delays, and staff departures.

CONCLUSIONS

Change is difficult to accept but essential when vital clinical activities are impaired and at risk. To maintain important clinical environments like the OR in an academic center, we developed and implemented effective, data-driven changes. This allowed us to retain critical human resources and restore a supportive environment for the patients, the doctors, and the staff.

Primary colonic lymphoma

Surgical resection of primary colonic lymphoma can be an important therapeutic tool. We performed a nonrandomized retrospective descriptive study at the University hospital tertiary care center. From January 1990 to June 2002, a total of 15 patients with primary colonic lymphoma were identified from the tumor registry at University of Alabama at Birmingham and retrospectively reviewed under Institutional Review Board approved protocol. Demographic data, clinical features, treatment method (surgery and/or chemotherapy), recurrence rate, and survival were analyzed. The results are presented as mean +/- standard deviation or median and range. Differences in survival were evaluated by the log-rank test and the interval of disease-free survival was calculated using the Kaplan-Meier method. A P value of <0.05 was considered statistically significant. Main outcome measures included surgical results, morbidity, mortality, and recurrence rate. Mean age was 51.5 years (standard deviation 16.4), 33 per cent were male and 67 per cent were female. Presenting symptoms were diarrhea (53.5%), lower gastrointestinal bleeding (13.3%), and nausea and vomiting (46.7%) secondary to low-grade obstruction. Concomitant colorectal disease was present in one patient with ulcerative colitis. Preoperative diagnosis of lymphoma was made in 13 patients (87%) with colonoscopy and biopsy. CT scan was performed in all patients; and none had radiographic evidence of systemic extension. Only one patient had a history of lymphoproliferative disease and exposure to radiation. The most common disease location was the cecum (60%), followed by the right colon (27%), and the sigmoid colon (13%). The mean lactic dehydrogenase (LDH) value was 214.9 u/L (range 129-309). Thirty-three per cent of the patients had an LDH value that was above the upper normal limit. LDH returned to normal after treatment in all patients. Operations performed consisted of right hemicolectomy (13), total proctocolectomy with ileal J J-pouch (1), and sigmoid colectomy (1). Eighty-seven per cent had negative margins at the time of operation. Twelve patients received postoperative chemotherapy (80%). According to the clinical classification of primary non-Hodgkin lymphoma (NHL) of the gastrointestinal tract (Lugano, 1993) all patients corresponded to stage IE. Mean hospital stay was 6.4 days (range 3-26). There was no surgical mortality and the morbidity rate was 20 per cent (3 patients). One patient had a systemic recurrence (7%) approximately 4 months after surgical resection. Mean follow-up was 31 months (median 2-73). Surgical resection of localized, primary colonic lymphoma provides excellent local disease control and should be considered a primary treatment option. The role of chemotherapy remains controversial depending on the grade, stage, and extension of residual disease.