Maheswari Senthil

The American Society of Peritoneal Surface Malignancies evaluation of HIPEC with Mitomycin C versus Oxaliplatin in 539 patients with colon cancer undergoing a complete cytoreductive surgery

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) are gaining acceptance as treatment for selected patients with colorectal cancer with peritoneal carcinomatosis (CRCPC). Tremendous variations exist in the HIPEC delivery.

Alkylation of cysteine 468 in Stat3 defines a novel site for therapeutic development

Stat3 is a latent transcription factor that promotes cell survival and proliferation and is often constitutively active in multiple cancers. Inhibition of Stat3 signaling pathways suppresses cell survival signals and leads to apoptosis in cancer cells, suggesting direct inhibition of Stat3 function is a viable therapeutic approach. Herein, we identify a small molecule, C48, as a selective Stat3-family member inhibitor. To determine its mechanism of action, we used site-directed mutagenesis and multiple biochemical techniques to show that C48 alkylates Cys468 in Stat3, a residue at the DNA-binding interface. We further demonstrate that C48 blocks accumulation of activated Stat3 in the nucleus in tumor cell lines that overexpress active Stat3, leading to impressive inhibition of tumor growth in mouse models. Collectively, these findings suggest Cys468 in Stat3 represents a novel site for therapeutic intervention and demonstrates the promise of alkylation as a potentially effective chemical approach for Stat3-dependent cancers.

The Role of the Cancer Center When Using Lymph Node Count as a Quality Measure for Gastric Cancer Surgery

IMPORTANCE Cancer center recognition, offered as accreditation by the American College of Surgeons Commission on Cancer or the National Cancer Institute, and quality measure reporting purport to improve the quality of cancer care. For surgically resectable gastric cancer, removal of 15 or more lymph nodes has been associated with improved outcomes and has been endorsed as a gastric cancer quality measure. OBJECTIVES To determine whether cancer center classification is associated with compliance with the lymph node-count quality measure and the effect of compliance with the measure on overall survival. DESIGN, SETTING, AND PARTICIPANTS A retrospective review of prospectively collected population-based data from the Surveillance, Epidemiology, and End Results Cancer Registry of Greater California and California Cancer Registry was conducted. Participants included patients who underwent surgery for stage I to III gastric adenocarcinoma between January 1, 2004, and December 31, 2010. MAIN OUTCOMES AND MEASURES Compliance with removal of 15 or more lymph nodes and overall survival. RESULTS Of 3321 gastric cancer cases, 42.3% had a minimum of 15 lymph nodes removed. Hospitals with cancer program recognition treated 69.9% of the cases. In hospitals without cancer program approval, 34.8% of the patients had 15 or more lymph nodes removed compared with 45.5% in the facilities with cancer program approval. Logistic regression analysis demonstrated that patients undergoing gastrectomy had significantly higher odds of having 15 or more lymph nodes removed if they were younger (trend P < .001), Asian/other race/ethnicity (adjusted odds ratio [AOR], 1.24; 95% CI, 1.03-1.50), or non-Hispanic black (AOR, 1.37; 95% CI, 1.03-1.82) compared with non-Hispanic white, received diagnosis at a progressively higher stage (trend P < .001), or received diagnosis in a more recent year (trend P < .001). Removal of 15 or more lymph nodes was associated with cancer program recognition (vs no recognition) (odds ratio, 1.48; 95% CI, 1.25-1.74). Cox proportional hazards regression showed that improved survival was predicted by removal of 15 or more lymph nodes (hazard ratio [HR], 0.70; 95% CI, 0.63-0.78) but not by cancer program recognition (HR, 1.03; 95% CI, 0.92-1.15). CONCLUSIONS AND RELEVANCE Although adequate lymph node retrieval is more likely in hospitals with a recognized cancer program, survival outcome is associated with the lymph node count rather than with cancer program classification. Less than half of the cases reviewed in this study met the minimum lymph node-count guideline, indicating the need for process improvement for all hospitals.

Postoperative management after hepatic resection

Hepatic resection has become the mainstay of treatment for both primary and certain secondary malignancies. Outcomes after hepatic resection have significantly improved with advances in surgical and anesthetic techniques and perioperative care. Metabolic and functional changes after hepatic resection are unique and cause significant challenges in management. In-depth understanding of hepatic physiology is essential to properly address the postoperative issues. Strategies implemented in the postoperative period to improve outcomes include adequate nutritional support, proper glycemic control, and interventions to reduce postoperative infectious complications among several others. This review article focuses on the major postoperative issues after hepatic resection and presents the current management.

Aryl Hydrocarbon Receptor Ligand 5F 203 Induces Oxidative Stress That Triggers DNA Damage in Human Breast Cancer Cells.

Breast tumors often show profound sensitivity to exogenous oxidative stress. Investigational agent 2-(4-amino-3-methylphenyl)-5-fluorobenzothiazole (5F 203) induces aryl hydrocarbon receptor (AhR)-mediated DNA damage in certain breast cancer cells. Since AhR agonists often elevate intracellular oxidative stress, we hypothesize that 5F 203 increases reactive oxygen species (ROS) to induce DNA damage, which thwarts breast cancer cell growth. We found that 5F 203 induced single-strand break formation. 5F 203 enhanced oxidative DNA damage that was specific to breast cancer cells sensitive to its cytotoxic actions, as it did not increase oxidative DNA damage or ROS formation in nontumorigenic MCF-10A breast epithelial cells. In contrast, AhR agonist and procarcinogen benzo[a]pyrene and its metabolite, 1,6-benzo[a]pyrene quinone, induced oxidative DNA damage and ROS formation, respectively, in MCF-10A cells. In sensitive breast cancer cells, 5F 203 activated ROS-responsive kinases: c-Jun-N-terminal kinase (JNK) and p38 mitogen activated protein kinase (p38). AhR antagonists (alpha-naphthoflavone, CH223191) or antioxidants (N-acetyl-l-cysteine, EUK-134) attenuated 5F 203-mediated JNK and p38 activation, depending on the cell type. Pharmacological inhibition of AhR, JNK, or p38 attenuated 5F 203-mediated increases in intracellular ROS, apoptosis, and single-strand break formation. 5F 203 induced the expression of cytoglobin, an oxidative stress-responsive gene and a putative tumor suppressor, which was diminished with AhR, JNK, or p38 inhibition. Additionally, 5F 203-mediated increases in ROS production and cytoglobin were suppressed in AHR100 cells (AhR ligand-unresponsive MCF-7 breast cancer cells). Our data demonstrate 5F 203 induces ROS-mediated DNA damage at least in part via AhR, JNK, or p38 activation and modulates the expression of oxidative stress-responsive genes such as cytoglobin to confer its anticancer action.

Size of Extranodal Extension on Sentinel Lymph Node Dissection in the American College of Surgeons Oncology Group Z0011 Trial Era

IMPORTANCE Based on the American College of Surgeons Oncology Group Z0011 trial exclusion criteria, patients with T1N0 or T2N0 breast cancer with 1 or 2 positive sentinel lymph nodes (SLNs) are recommended to undergo axillary lymph node dissection if extranodal extension (ENE) is present. OBJECTIVE To determine the effect of ENE size on residual axillary nodal burden, disease recurrence, and survival in patients meeting Z0011 criteria. DESIGN, SETTING, AND PARTICIPANTS Retrospective cohort study between January 1, 2000, and December 31, 2012, at a single tertiary cancer center. Patients had T1 or T2 breast cancer with 1 or 2 positive SLNs. The ENE was classified as 2 mm or smaller or as larger than 2 mm. MAIN OUTCOMES AND MEASURES Nodal burden, disease recurrence, and overall survival. RESULTS Of 208 patients, 149 (71.6%) had no ENE, 21 (10.1%) had ENE 2 mm or smaller, and 38 (18.3%) had ENE larger than 2 mm on SLN dissection. The median follow-up time was 60 months (range, 1-158 months). The mean (SD) total number of positive lymph nodes differed significantly for the group with no ENE (1.72 [1.39]) vs the group with ENE 2 mm or smaller (3.22 [2.09]; P < .001) and vs the group with ENE larger than 2 mm (4.26 [5.01]; P < .001). Similar patterns were observed for mean (SD) nonsentinel lymph node metastases: 0.48 (1.30) for no ENE vs 1.91 (2.07) with ENE 2 mm or smaller (P = .02) and vs 2.95 (4.95) with ENE larger than 2 mm (P < .001). For the group without ENE vs the group with ENE 2 mm or smaller, there were no significant differences in recurrence (distant recurrence, 4 patients [2.7%] vs 1 patient [4.8%], respectively; P = .62) or in mortality (18 patients [12.1%] vs 4 patients [19.1%], respectively; P = .48). For the group without ENE vs the group with ENE larger than 2 mm, there were no significant differences in recurrence (distant recurrence, 4 patients [2.7%] vs 4 patients [10.5%], respectively; P = .19) or in mortality (18 patients [12.1%] vs 9 patients [23.7%], respectively; P = .07). CONCLUSIONS AND RELEVANCE Presence of ENE on SLN dissection is associated with N2 disease. Despite increased nodal burden, patients with 1 or 2 positive SLNs and ENE 2 mm or smaller demonstrated recurrence and survival rates similar to those of patients without ENE. Reporting of ENE size should be standardized and required.

Identification of a Natural Compound by Cell-Based Screening That Enhances Interferon Regulatory Factor-1 Activity and Causes Tumor Suppression

The transcription factor interferon regulatory factor-1 (IRF-1) is induced by many tumor-suppressive stimuli and can mediate antiproliferative and proapoptotic effects in cancer cells. Thus, identifying agents that enhance IRF-1 activity may be an effective approach to cancer therapy. A cell-based screening assay was developed to identify extracts and compounds that could enhance IRF-1 activity, using an IRF-1–dependent luciferase reporter cell line. Through this approach, we identified a natural product extract and a known active component of this extract, baicalein, which causes a marked increase in IRF-1–dependent reporter gene expression and IRF-1 protein, with modulation of known IRF-1 targets PUMA and cyclin D1. Baicalein causes suppression of growth in vitro in multiple cancer cell lines in the low micromolar range. IRF-1 plays a role in this growth suppression as shown by significant resistance to growth suppression in a breast cancer cell line stably transfected with short hairpin RNA against IRF-1. Finally, intraperitoneal administration of baicalein by repeated injection causes inhibition of growth in both xenogeneic and syngeneic mouse models of cancer without toxicity to the animals. These findings indicate that identifying enhancers of IRF-1 activity may have utility in anticancer therapies and that cell-based screening for activation of transcription factors can be a useful approach for drug discovery. Mol Cancer Ther; 10(10); 1774–83. ©2011 AACR.

Peritoneal carcinomatosis: limits of diagnosis and the case for liquid biopsy

Peritoneal Carcinomatosis (PC) is a late stage manifestation of several gastrointestinal malignancies including appendiceal, colorectal, and gastric cancer. In PC, tumors metastasize to and deposit on the peritoneal surface and often leave patients with only palliative treatment options. For colorectal PC, median survival is approximately five months, and palliative systemic therapy is able to extend this to approximately 12 months. However, cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS/HIPEC) with a curative intent is possible in some patients with limited tumor burden. In well-selected patients undergoing complete cytoreduction, median survival has been reported as high as 63 month. Identifying patients earlier who are either at risk for, or who have recently developed PC may provide them with additional treatment options such as CRS/HIPEC. PC is diagnosed late by imaging findings or often times during an invasive procedures such as laparoscopy or laparotomy. In order to improve the outcomes of PC patients, a minimally invasive, accurate, and specific PC screening method needs to be developed. By utilizing circulating PC biomarkers in the serum of patients, a “liquid biopsy,” may be able to be generated to allow a tailored treatment plan and early intervention. Exosomes, stable patient-derived nanovesicles present in blood, urine, and many other bodily fluids, show promise as a tool for the evaluation of labile biomarkers. If liquid biopsies can be perfected in PC, manifestations of this cancer may be more effectively treated, thus offering improved survival.

Down-regulation of LXR/RXR activation and negative acute phase response pathways in colon adenocarcinoma revealed by proteomics and bioinformatics analysis

BACKGROUND AND OBJECTIVE Deficiency of vitamin D could be a major cause of colon cancer as suggested as early as 1980 by Drs. Cedric and Frank Garland of the University of California and has recently been underscored by a large European case control study. Whether vitamin D deficiency is because of inadequate intake (food and sunshine) or because of vitamin D metabolism disorder in the patient body is unknown. A proteomics approach to identify protein pathways associated with vitamin D transportation and metabolism pathways will help us understand better the pathology of the colon cancer. METHODS Lysates of colon adenocarcinoma tissues and their matched healthy tissues, from seven colon cancer patients, have been evaluated by quantitative proteomics and bioinformatics analysis to determine protein expression profiles. Unsupervised hierarchical clustering and principle component analysis (PCA) were utilized for protein expression profiling and biomarker identification, while the reporter ion ratios from tandem-mass-tagging (TMT) labeled peptides were used for quantification. Ingenuity Pathway Analysis (IPA) was used to analyze protein pathways. RESULTS AND CONCLUSION Proteomics analyses demonstrated that the proteins involved in vitamin D/E binding, heme/iron binding and transportation, and lipid/steroid transportation/metabolic systems were down-regulated in colon cancer and the same set of proteins were down-regulated in the LXR/RXR activation and acute-phase response pathways, revealing a plausible mechanistic connection between vitamin D deficiency, iron homeostasis, and colon cancer.

Surgical and radiation therapy management of recurrent anal melanoma

BACKGROUND Melanoma of the anorectal mucosa is a rare but highly aggressive tumor. Its presenting symptoms are frequently confused with hemorrhoids, thereby causing a delay in diagnosis. Anorectal melanoma carries with it a very poor prognosis. There is a paucity of data investigating management options for anorectal melanoma, and even fewer data reporting recurrent or refractory cases. CASE PRESENTATION This case documents a 41-year-old female with a long history of hemorrhoids presenting with anorectal discharge. She was incidentally found have anorectal melanoma following surgical resection. Systemic diagnostic work-up demonstrated PET-avid lymphadenopathy in her right groin. She underwent right groin dissection. However, seven months later she recurred in her right groin and a new recurrent mass was found in her pelvis. She underwent a second groin dissection and resection of the pelvic recurrence. This was followed by a course of hypofractionated radiation therapy then systemic immunotherapy. DISCUSSION Surgery has been the mainstay of treatment. However, the extent of surgery has been the topic of investigation. Historically, radical resections have been performed but they result in high rates of post-operative morbidity. Newer studies have compared radical resection with wide local excisions and found comparable outcomes. Anorectal melanoma is frequently a systemic disease. The ideal systemic therapy regimen has not yet been determined but numerous studies show a benefit to multi-agent treatments. Radiation therapy is typically given in the post-operative or palliative setting. CONCLUSIONS Anorectal mucosal melanoma is a very rare but aggressive disease with a poor prognosis. The overall treatment goal should strive to optimize quality of life and tumor control while minimizing treatment-related morbidities.