Abstract 1787: Statin therapy enhances the efficacy of HER2 directed antibody-drug conjugates in breast cancer

Antibody-drug conjugates (ADCs) targeting human epidermal growth factor receptor 2 (HER2) are a widely successful strategy for the treatment of HER2-positive breast cancer. Despite the demonstrated efficacy, intrinsic and acquired resistance to anti-HER2 ADCs remains a major challenge. The activity of ADCs is dependent upon the internalization of the HER2-ADC complex into specific subcellular compartments permissive for release of the chemotherapeutic payload. Previous studies have demonstrated that statins, a commonly used cholesterol-lowering medication, could increase plasma membrane-bound HER2 and improve trastuzumab efficacy in HER2-positive gastric cancer. In this study, we sought to characterize the impact of statins on the efficacy of HER2 ADCs. We performed in vitro internalization assays with trastuzumab emtansine (T-DM1) labeled with a pH-sensitive pHrodo fluorogenic dye to monitor T-DM1 entering lysosome whereupon payload DM1 is released, and found that combined treatment of T-DM1 and lovastatin potently enhanced T-DM1 internalization of T-DM1 into lysosome in HER2-amplified and HER2-low models. Consistent with the internalization assays, lovastatin increased cell death caused by T-DM1 and sensitized the HER2-low ZR75-1 cells to T-DM1 treatment in vitro. Using HER2-positive xenograft models, we found orally administrated lovastatin promoted T-DM1 uptake in tumors and enhanced T-DM1 efficacy in vivo. To investigate whether these results might be observed in the clinic, we conducted retrospective analyses on a cohort of 164 HER2 positive metastatic breast cancer patients treated at MSKCC who received T-DM1. Among these patients, 21 (12.8%) were taking statins concurrently with T-DM1, and the median progression-free survival in the patients who received statins was 14 months (95% confidence interval, 3.5-24 months) compared to 5.4 months (95% confidence interval, 3.9-7.0 months) in those who had no record of statin use (p=0.1). Overall, our findings demonstrate that statins potentiate the susceptibility of breast cancer cells to anti-HER2 ADCs by modulating HER2 membrane dynamics and HER2-ADC internalization, suggesting statin as a rational therapeutic partner for anti-HER2 ADC in HER2-positive breast cancer, especially those with relatively low HER2 expression.

Citation Format: Bo Liu, Joshua Z. Drago, Yi Rao, Patricia R. Pereira, Anton Safonov, Antonio Marra, Mehnaj S. Ahmed, Shanu Modi, Jorge S. Reis-Filho, Filippo Montemurro, Pedram Razavi, Jason S. Lewis, Sarat Chandarlapaty. Statin therapy enhances the efficacy of HER2 directed antibody-drug conjugates in breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1787.

Abstract P2-13-19: Statin modulation of antibody drug conjugate activity in breast cancer models and patients

Background: Membrane HER2 expression levels strongly influence the activity of anti-HER2 therapies directed at the HER2 extracellular domain (1,2). Tumoral cell-surface caveolin-1 (CAV-1) regulates receptor tyrosine kinase membrane trafficking mechanisms (1,3). In xenograft models, CAV-1 can be modulated with cholesterol-depleting drugs, such as statins. We hypothesized that preclinical and clinical use of statins might influence the expression of CAV-1 and thereby affect the efficacy of anti-HER2 antibody-drug conjugates (ADCs) in breast cancer. Methods: Preclinically, statins were given alone and in combination with HER2 antibody drug conjugates such as T-DM1 to assess HER2 levels, drug uptake, and antitumor efficacy in HER2-positive cancer models. Mice received an intravenous injection of T-DM1, oral doses of lovastatin, or a combination of T-DM1 and lovastatin, for 5 weeks. Clinically, we performed retrospective analyses of HER2-positive MBC patients at MSKCC who received T-DM1 and consented to molecular profiling and clinical data abstraction. Progression-free survival (PFS) on T-DM1 was estimated using Kaplan Meyer methods and compared using the log rank test. Univariable and multivariable Cox proportional hazards models were constructed using relevant clinical covariates. Results: Tumor models with high levels of CAV-1 exhibit low HER2 density on the cell surface and show low T-DM1 targeted immunoPET binding when compared with CAV-1-low tumors. Mechanistic studies showed that CAV-1 depletion in HER2-positive BC cells temporally stabilizes HER2 on the surface and delays T-DM1 recycling. In preclinical BC models, CAV-1 depletion induced by synthetic oligonucleotides or statins enhances T-DM1 binding and efficacy in tumors with incomplete HER2 membranous reactivity. For clinical analyses, a total of 164 patients who received T-DM1 were included in the final analysis. Twenty-one (12.8%) of these patients were recorded to be taking statins concurrently with T-DM1, as part of their routine clinical care. Compared with patients with no recorded statin use, patients receiving statins were older on average (median age 58 vs. 50 years, p = 0.007), but did not differ in their race, histologic breast cancer type, ER status, or T-DM1 treatment line. Median PFS on T-DM1 in the overall cohort was 5.5 months. Median PFS in patients who received statins was 14 months vs. 5.4 months in patients who had no recorded statin use (p = 0.1). In univariable Cox analysis, the association between statin use and PFS did not reach statistical significance (p=0.119). In a multivariable analysis including age, ER status, treatment line, and breast cancer histology, no variable reached statistical significance. However, statin use had the greatest observed degree of association with PFS (p = 0.17). Conclusions: Statins modulate surface HER2 levels and T-DM1 efficacy preclinically via CAV-1. Although only a numerical difference in outcomes was observed in the MSKCC cohort, the effect appeared meaningful and therefore assessment in larger patient cohorts is now underway. Based on the results of these forthcoming analyses, prospective trials may be justified that integrate these well-tolerated and low-cost agents into HER2 ADC treatment regimens. References:1-Pereira P. et al Nat Commun 9, 5137 (2018)2-Chew H.Y. et al Cell 180, 895 (2020)3-Pereira P. et al Clin Cancer Res 26, 6215 (2020)

Citation Format: Joshua Z Drago, Patricia R Pereira, Anton Safonov, Antonio Marra, Yi Rao, Bo Liu, Mehnaj Ahmed, Shanu Modi, Jorge Reis-Filho, Mark Robson, Filippo Montemurro, Pedram Razavi, Jason S Lewis, Sarat Chandarlapaty. Statin modulation of antibody drug conjugate activity in breast cancer models and patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P2-13-19.

Saccharomyces cerevisiae biomass as a source of next-generation food preservatives: Evaluating potential proteins as a source of antimicrobial peptides

Saccharomyces cerevisiae is the main biotechnological tool for the production of Baker's or Brewer's biomasses, largely applied in beverage and fermented-food production. Through its gene expression reprogramming and production of compounds that inactivate the growth of other microorganisms, S. cerevisiae is able to grow in adverse environments and in complex microbial consortia, as in fruit pulps and root flour fermentations. The distinct set of up-regulated genes throughout yeast biomass propagation includes those involved in sugar fermentation, ethanol metabolization, and in protective responses against abiotic stresses. These high abundant proteins are precursors of several peptides with promising health-beneficial activities such as antihypertensive, antioxidant, antimicrobial, immunomodulatory, anti-obesity, antidiabetes, and mitogenic properties. An in silico investigation of these S. cerevisiae derived peptides produced during yeast biomass propagation or induced by physicochemical treatments were performed using four algorithms to predict antimicrobial candidates encrypted in abundantly expressed stress-related proteins encoded by different genes like AHP1, TSA1, HSP26, SOD1, HSP10, and UTR2, or metabolic enzymes involved in carbon source utilization, like ENO1/2, TDH1/2/3, ADH1/2, FBA1, and PDC1. Glyceraldehyde-3-phosphate dehydrogenase and enolase II are noteworthy precursor proteins, since they exhibited the highest scores concerning the release of antimicrobial peptide candidates. Considering the set of genes upregulated during biomass propagation, we conclude that S. cerevisiae biomass, a food-grade product consumed and marketed worldwide, should be considered a safe and nonseasonal source for designing next-generation bioactive agents, especially protein encrypting antimicrobial peptides that display broad spectra activity and could reduce the emergence of microbial resistance while also avoiding cytotoxicity.

ImmunoPET Predicts Response to Met-targeted Radioligand Therapy in Models of Pancreatic Cancer Resistant to Met Kinase Inhibitors

Background: Pancreatic ductal adenocarcinoma (PDAC) has limited standard of care therapeutic options. While initially received with enthusiasm, results from targeted therapy with small molecule tyrosine kinases inhibitors (TKIs) have been mixed, in part due to poor patient selection and compensatory changes in signaling networks upon blockade of one or more kinase of tumors. Here, we demonstrate that in PDACs otherwise resistant to rational kinase inhibition, Met-directed immuno-positron emission tomography (immunoPET) can identify targets for cell-signaling independent targeted radioligand therapy (RLT). In this study, we use Met-directed immunoPET and RLT in models of human pancreatic cancer that are resistant to Met- and MEK-selective TKIs, despite over-expression of Met and KRAS-pathway activation. Methods: We assessed cell membrane Met levels in human patient samples and pancreatic ductal adenocarcinoma (PDAC) cell lines (BxPC3, Capan2, Suit2, and MIA PaCa-2) using immunofluorescence, flow cytometry and cell-surface biotinylation assays. To determine whether Met expression levels correlate with sensitivity to Met inhibition by tyrosine kinase inhibitors (TKIs), we performed cell viability studies. A Met-directed imaging agent was engineered by labeling Met-specific onartuzumab with zirconium-89 (Zr-89) and its in vivo performance was evaluated in subcutaneous and orthotopic PDAC xenograft models. To assess whether the immunoPET agent would predict for targeted RLT response, onartuzumab was then labeled with lutetium (Lu-177) as the therapeutic radionuclide to generate our [¹⁷⁷Lu]Lu-DTPA-onartuzumab RLT agent. [¹⁷⁷Lu]Lu-DTPA-onartuzumab was administered at 9.25MBq (250μCi)/20μg in three fractions separated by three days in mice subcutaneously engrafted with BxPC3 (high cell-membrane Met) or MIA PaCa-2 (low cell-membrane Met). Primary endpoints were tumor response and overall survival. Results: Flow cytometry and cell-surface biotinylation studies showed that cell-membrane Met was significantly more abundant in BxPC3, Capan2, and Suit2 when compared with MIA PaCa-2 pancreatic tumor cells. Crizotinib and cabozantinib, TKIs with known activity against Met and other kinases, decreased PDAC cell line viability in vitro. The TKI with the lowest IC₅₀ for Met, capmatinib, had no activity in PDAC lines. No additive effect was detected on cell viability when Met-inhibition was combined with MEK1/2 inhibition. We observed selective tumor uptake of [⁸⁹Zr]Zr-DFO-onartuzumab in mice subcutaneously and orthotopically engrafted with PDAC lines containing high cell-surface levels of Met (BxPC3, Capan2, Suit2), but not in mice engrafted with low cell-surface levels of Met (MIA PaCa-2). Significant tumor growth delay and overall survival benefit were observed in both BxPC3 and MIA PaCa-2 engrafted animals treated with RLT when compared to controls, however, the benefit was more pronounced and more durable in the BxPC3 engrafted animals treated with [¹⁷⁷Lu]Lu-DTPA-onartuzumab RLT. Conclusions: Our findings demonstrate that while over-expression of Met is not predictive of Met-directed TKI response, immunoPET can detect Met over-expression in vivo and predicts for therapeutic response to Met-selective RLT. This phenomenon can be exploited for other Met-overexpressing tumor types specifically, and to any differentially overexpressed surface molecule more broadly.

Preparation and Characterization of Nanoliposomes for the Entrapment of Bioactive Hydrophilic Globular Proteins

Liposome nanocapsules have been applied for many purposes in the pharmaceutical, cosmetic, and food industries. Attributes of liposomes include their biocompatibility, biodegradability, non-immunogenicity, non-toxicity, and ability to entrap both hydrophilic and hydrophobic compounds. The classical hydration of thin lipid films in an organic solvent is applied herein as a technique to encapsulate tarin, a plant lectin, in nanoliposomes. Nanoliposome size, stability, entrapment efficiency, and morphological characterization are described in detail. The nanoliposomes are prepared using 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine (DOPE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[amino(polyethylene glycol)-2000] (ammonium salt; DSPE-MPEG 2000), and cholesterylhemisuccinate (CHEMS) as the main constituents. Lipids are first dissolved in chloroform to obtain a thin lipid film that is subsequently rehydrated in ammonium sulfate solution containing the protein to be entrapped and incubated overnight. Then, sonication and extrusion techniques are applied to generate nanosized unilamellar vesicles. The size and polydispersity index of the nanovesicles are determined by dynamic light scattering, while nanovesicle morphology is assessed by scanning electron microscopy. Entrapment efficiency is determined by the ratio of the amount of unencapsulated protein to original amount of initially loaded protein. Homogeneous liposomes are obtained with an average size of 155 nm and polydispersity index value of 0.168. A high entrapment efficiency of 83% is achieved.

Liposomal Taro Lectin Nanocapsules Control Human Glioblastoma and Mammary Adenocarcinoma Cell Proliferation

The search for natural anticancer agents and nanocarrier uses are a part of the current strategies to overcome the side effects caused by chemotherapeutics. Liposomal nanocapsules loaded with purified tarin, a potential immunomodulatory and antitumoral lectin found in taro corms, were produced. Liposomes were composed by 1,2-dioleoyl-sn-glycerol-3-phosphoethanolamine, cholesterylhemisuccinate, and 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[folate(polyethylene glycol)-2000 prepared by thin-film hydration. Small unilamellar vesicles were achieved by sonication and extrusion. Scanning electron microscopy evidenced round-shaped nanocapsules presenting a smooth surface, 150 nm diameter and polydispersity index <0.2, estimated by dynamic light scattering. Tarin entrapment rates were over 80% and leakage of ~3% under 40 days of storage at 4 °C. Entrapped tarin exhibited an 83% release after 6 h at pH 4.6⁻7.4 and 36 °C. Both free and encapsulated tarin exhibited no in vitro toxicity against healthy mice bone marrow and L929 cells but stimulated the production of fibroblast-like and large round-shaped cells. Encapsulated tarin resulted in inhibition of human glioblastoma (U-87 MG) and breast adenocarcinoma (MDA-MB-231) proliferation, with an IC50 of 39.36 and 71.38 µg/mL, respectively. The effectiveness of encapsulated tarin was similar to conventional chemotherapy drugs, such as cisplatin and temozolide. Tarin liposomal nanocapsules exhibited superior pharmacological activity compared to free tarin as a potential chemotherapy adjuvant.

Tarin stimulates granulocyte growth in bone marrow cell cultures and minimizes immunosuppression by cyclo-phosphamide in mice

Chemotherapeutic drugs, such as cyclophosphamide, cause severe immunosuppression and patients become susceptible to infections. Based on this, the immunomodulatory potential of tarin, a lectin from Colocasia esculenta, was evaluated in bone marrow cell cultures and in cyclophosphamide-immunosuppressed mice. Tarin promoted maintenance of hematopoietic progenitors and repopulation of Gr1 cells in vitro which was supported by in vivo results. In immunosuppressed mice, tarin increased bone marrow cell numbers and altered cell profile distribution by enhancing the frequency of Gr1+ progenitors, including Ly6-CintLy6-Glo, and anticipating their proliferation/differentiation in mature cells, especially Ly6-CloLy6-Ghi. Bone marrow cells harvested from tarin-treated immunosuppressed mice proliferated in response to GM-CSF or G-CSF in vitro and, the low numbers of bone marrow cells in the G0 phase, combined with a high number cells undergoing apoptosis confirmed that tarin promoted a faster and intense proliferation/differentiation, even in the presence of CY-induced toxicity. As a result, tarin minimized leukopenia in immunosuppressed mice promoting a faster recovery of peripheral leucocytes and protected erythroid bone marrow cells from CY-cytotoxicity in a dose-dependent manner. Data suggest that tarin could be considered a potential adjuvant to decrease leukopenia and possibly ameliorate anemia, if carefully evaluated in human cancer cell lineages and in clinical trials.

Neurotoxicosis in horses associated with consumption of Trema micrantha

BACKGROUND

Trema micrantha is a tree widely distributed throughout the Americas. The tree produces highly palatable leaves that have been associated with natural poisoning in goats, sheep and horses, in which hepatic necrosis and hepatic encephalopathy have been observed.

OBJECTIVES

This study describes malacia and haemorrhage in the central nervous system (CNS) due to T. micrantha consumption, with minimal to absent hepatic lesions.

STUDY DESIGN

Retrospective case series.

METHODS

A total of 14 horses with a history of neurological signs and spontaneous consumption of T. micrantha leaves were submitted to necropsy and multiple samples were collected for histopathology. Details of clinical history and signs of the horses were obtained through inquiries to the owners and attending veterinarians.

RESULTS

All the 14 horses had neurological signs of ataxia, severe sialorrhoea, involuntary running movements, sternal and lateral recumbency, and death after a clinical course that lasted from 24 h to 9 days. For a few days prior to onset of clinical signs, all horses had spontaneously consumed, potentially toxic doses of T. micrantha leaves. All 14 brains had diffuse yellowish discoloration affecting the rhombencephalon, mesencephalon, diencephalon, telencephalon and corpus striatum. In all cases, the most severe lesions were observed in the pons. Spinal cord lesions were observed affecting the lumbar intumescence, which was swollen with darken and depressed areas at the dorsal and ventral horns, and at the sacral level, which on cut surface displayed a friable and yellowish grey matter. The lesions observed grossly in brain and spinal cord consisted microscopically of severe vasculitis and liquefactive necrosis of white and grey matter of the brainstem, cerebellum and spinal cord.

MAIN LIMITATIONS

This is a small retrospective series relying on clinical observations reported by owners and attending veterinarians. The mechanism of action of the plant toxin in the CNS is still unidentified.

CONCLUSION

T. micrantha poisoning in horses causes predominantly a neurological disease, with minimal to absent hepatic lesions.

High-resolution crystal structures of Colocasia esculenta tarin lectin

Tarin, the Colocasia esculenta lectin from the superfamily of α-d-mannose-specific plant bulb lectins, is a tetramer of 47 kDa composed of two heterodimers. Each heterodimer possesses homologous monomers of ~11.9 (A chain) and ~12.7 (B chain) kDa. The structures of apo and carbohydrate-bound tarin were solved to 1.7 Å and 1.91 Å, respectively. Each tarin monomer forms a canonical β-prism II fold, common to all members of Galanthus nivalis agglutinin (GNA) family, which is partially stabilized by a disulfide bond and a conserved hydrophobic core. The heterodimer is formed through domain swapping involving the C-terminal β-strand and the β-sheet on face I of the prism. The tetramer is assembled through the dimerization of the B chains from heterodimers involving face II of each prism. The 1.91 Å crystal structure of tarin bound to Manα(1,3)Manα(1,6)Man reveals an expanded carbohydrate-binding sequence (QxDxNxVxYx_4/6WX) on face III of the β-prism. Both monomers possess a similar fold, except for the length of the loop, which begins after the conserved tyrosine and creates the binding pocket for the α(1,6)-terminal mannose. This loop differs in size and amino-acid composition from 10 other β-prism II domain proteins, and may confer carbohydrate-binding specificity among members of the GNA-related lectin family.

Histopathological Diagnosis of Corneal Button Specimens: An Epidemiological Study

PURPOSE

To determine the most common histopathological diagnosis of corneal specimens from penetrating keratoplasty (PKP).

METHODS

The records of 500 corneal specimens submitted to biopsy at the Henry Witelson Ocular Pathology Laboratory, Montreal, Canada, from 1999 to 2004 were reviewed. Age, sex, clinical indications, and histopathological findings were analyzed.

RESULTS

Chronic keratitis (45.6%) was the most common pathological diagnosis, followed by corneal edema (25.8%), dystrophy (12.8%), keratoconus (KC) (9.2%), acute keratitis (5.6%), and degeneration (1.0%). Among the specimens with chronic keratitis, regraft was the most common clinical indication (39.0%). In the group of acute keratitis, ulcerative condition was the leading cause (75,0%). Fuchs' endothelial dystrophy represented 79.7% of the clinical diagnoses in the group of corneal dystrophies. The median patient age was 70-79 years, and the gender distribution was nearly symmetric.

CONCLUSION

The present study is important for determining the most common histopathological diagnoses of corneal button specimens and the correlation with the age, gender, and clinical indications of PKP.

Measurement of anterior lens growth after acute primary angle-closure glaucoma

CASE REPORT

We report a case of choroidal melanoma metastatic to the liver diagnosed by fine-needle aspiration. The biopsy sample was immunostained for COX-2 and c-kit.

COMMENTS

Accurate diagnosis and identification of potential therapeutic targets are important for subsequent therapy and can be achieved by radiologically guided fine-needle aspiration biopsy.

Orbital metastasis of urinary bladder carcinoma: a clinicopathologic report and review of the literature

A 53-year-old male presented with a progressive mass of the left orbit. His medical history included an invasive carcinoma of the bladder diagnosed three weeks earlier. An orbital biopsy was performed and the diagnosis was that of an orbital metastasis of urinary bladder carcinoma. The patient developed widespread metastatic disease and unfortunately died one month after the diagnosis of orbital metastasis. Orbital metastasis of urinary bladder carcinoma is associated with a poor prognosis and is more frequently observed in older people. In addition, it is five times more prevalent in men than in women.

Corneal Endothelial Deposits Associated with Rifabutin Use

PURPOSE

The aim of this study was to report on the possible development of corneal endothelial deposits resulting from the use of rifabutin.

METHODS

Case series consisting of 3 patients treated with rifabutin were retrospectively studied. Two of the patients were infected with human immunodeficiency virus. A corneal and external disease specialist performed a complete ophthalmologic exam and obtained medical histories of the patients.

RESULTS

All cases developed corneal endothelial deposits after previous use of rifabutin. The deposits were bilateral, yellow-white colored, stellate, and mainly peripheral.

CONCLUSIONS

In these 3 cases, the unique positive ocular finding was corneal endothelial deposits, which may be related to the use of rifabutin.

Transabdominal or totally extraperitoneal laparoscopic hernia repair?

Laparoscopic repair of inguinal hernias follows some principles that have already proven its efficiency, as a posterior approach and the prosthetic repair that allows a "tension-free" repair with consequent early return to work and low recurrence rate. To determine the most appropriate laparoscopic repair, we compared the transabdominal preperitoneal (TAPP) and the totally extraperitoneal (TEP) approach. Patients undergoing TAPP and TEP were compared regarding technical feasibility and difficulties, time until return to work and follow-up, including intraoperative and postoperative complications. Seventy-eight patients (108 hernias) were submitted to TAPP and 67 (100 hernias) were repaired through TEP. All data were analyzed by Yates-corrected chi-square test to qualitative analysis of each group and p < or = 0.05 was considered significant. Both procedures were indicated mainly for bilateral and/or recurrent hernias (68%). The operative time was shorter in TAPP (not statistically significant). Surgeons complained of more technical difficulties while performing the TEP approach (70% complaints of difficulty in TEP--four conversions to TAPP). There was no difference in hospital stay (mean of 30 h) and return to work (TAPP 7 days and TEP 5.5 days). Regarding the complication rate (TAPP = 20.5% and TEP = 13.5%; not significant), none were related to the pneumoperitoneum technique or its systemic effects. In the TAPP approach, two trocar site hernias occurred, and in the TEP approach, one severe cellulitis occurred, which was managed without surgical intervention. The mean follow-up period for each procedure was not the same, so the recurrence rates are not comparable statistically (rate of 1.85% in TAPP and 0 in TEP). Both techniques are safe and have the same advantages, but TAPP is easier: a better view of the anatomy is achieved, shortening the learning curve. We suggest that TAPP can be an adequate laparoscopic approach to groin hernias. A longer follow-up period and more cases are needed to determine recurrence rates.

Laparoscopy-assisted colonoscopic polypectomy

One of the most feared complications in the removal of moderate-sized or large sessile polyps is colonic perforation. Complete colonoscopic total excision of these kinds of polyps can be safely undertaken using laparoscopic assistance, which enables prompt diagnosis and treatment of perforation. Laparoscopy-assisted endoscopic polyp excision can be safely performed, avoiding critical septic complications and can also help in the selection of patients to appropriate colonic resection without increasing morbidity or mortality.