Treatment of metastatic colon cancer: "the times they are A-changing"

Intraarterial Chemotherapy for Liver Metastases

Colorectal cancer (CRC) is one of the leading cancers globally in terms of both incidence and cancer-related mortality. Liver metastatic disease is the main prognostic driver for patients with CRC. The management options for liver metastatic CRC continue to evolve, particularly with the incorporation of locoregional therapies into the treatment paradigm. Hepatic arterial infusion (HAI) chemotherapy is one such liver directed approach used with the goal of converting patients to liver resection, reducing the risk of recurrence, treating recurrent disease, and most importantly improving overall survival. This article summarizes the role of HAI chemotherapy in the treatment of liver metastatic CRC.

Prediction of liver metastasis and recommended optimal follow-up nursing in rectal cancer

We aimed to analyze and investigate the clinical factors that influence the occurrence of liver metastasis in locally advanced rectal cancer patients, with an attempt to assist patients in devising the optimal imaging-based follow-up nursing. Between June 2011 and May 2021, patients with rectal cancer at our hospital were retrospectively analyzed. A random survival forest model was developed to predict the probability of liver metastasis and provide a practical risk-based approach to surveillance. The results indicated that age, perineural invasion, and tumor deposit were significant factors associated with the liver metastasis and survival. The liver metastasis risk of the low-risk group was higher at 6-21 months, with a peak occurrence time in the 15th month. The liver metastasis risk of the high-risk group was higher at 0-24 months, with a peak occurrence time in the 8th month. In general, our clinical model could predict liver metastasis in rectal cancer patients. It provides a visualization tool that can aid physicians and nurses in making clinical decisions, by detecting the probability of liver metastasis.

Long-Term Survivors of Metastatic Colorectal Cancer: A Tertiary Care Centre Experience

Background Prognosis of metastatic colorectal cancer (mCRC) is poor and goal of treatment is mainly palliative unless there is limited metastatic disease which is surgically resectable. Here, we report a case series of long-term survivors treated predominantly with chemotherapy.

Methods This is a single-center retrospective analysis of patients of mCRC. Records of metastatic colorectal cancer patients registered at Institute Rotary Cancer Hospital, All India Institute of Medical Sciences, New Delhi, between the year 2005 and 2015 were retrieved and reviewed. Inclusion criteria were patients who survived 5 years or more, treated mainly by chemotherapy, with either initial presentation as metastatic disease or those who progressed after initial surgery with or without adjuvant therapy. The details about the patient characteristics, treatment, and outcome were collected. The data were censored on September 30, 2020.

Results Records of 370 mCRC patients were reviewed. Thirty-one patients with all the available details fulfilled the criteria for inclusion in the study. Median age was 53 years (range, 22–74 years). Sixteen were women (51.6%). Twenty-four (77%) were newly diagnosed cases with initial presentation as metastatic disease. Commonest site of primary was on the left (21, 67.6%) followed by right side and transverse colon in 5 patients each. Liver was the most common site of metastasis ( n = 18, 58.06%). In metastatic setting, the most common chemotherapy regimen used in the first line was CAPOX ( n = 11, 35.48%). Only three patients could undergo metastatectomy. Monoclonal antibodies could be used only in 14 patients. Median overall survival (OS) of this cohort is 81.6 months (95% confidence interval [CI], 69.73–117.9).

Conclusion A small but significant proportion of mCRC patients may achieve and maintain durable responses and long term survival with use of combination of chemotherapy with or without biologics.

Intraarterial Chemotherapy for Liver Metastases

Colorectal cancer (CRC) is one of the leading cancers globally in terms of both incidence and cancer-related mortality. Liver metastatic disease is the main prognostic driver for patients with CRC. The management options for liver metastatic CRC continue to evolve, particularly with the incorporation of locoregional therapies into the treatment paradigm. Hepatic arterial infusion (HAI) chemotherapy is one such liver directed approach used with the goal of converting patients to liver resection, reducing the risk of recurrence, treating recurrent disease, and most importantly improving overall survival. This article summarizes the role of HAI chemotherapy in the treatment of liver metastatic CRC.

pH-Responsive Artesunate Polymer Prodrugs with Enhanced Ablation Effect on Rodent Xenograft Colon Cancer

Purpose

In this study, pH-sensitive poly(2-ethyl-2-oxazoline)-poly(lactic acid)-poly(β-amino ester) (PEOz-PLA-PBAE) triblock copolymers were synthesized and were conjugated with an antimalaria drug artesunate (ART), for inhibition of a colon cancer xenograft model.

Methods

The as-prepared polymer prodrugs are tended to self-assemble into polymeric micelles in aqueous milieu, with PEOz segment as hydrophilic shell and PLA-PBAE segment as hydrophobic core.

Results

The pH sensitivity of the as-prepared copolymers was confirmed by acid-base titration with pKb values around 6.5. The drug-conjugated polymer micelles showed high stability for at least 96 h in PBS and 37°C, respectively. The as-prepared copolymer prodrugs showed high drug loading content, with 9.57%±1.24% of drug loading for PEOz-PLA-PBAE-ART4. The conjugated ART could be released in a sustained and pH-dependent manner, with 92% of released drug at pH 6.0 and 57% of drug released at pH 7.4, respectively. In addition, in vitro experiments showed higher inhibitory effect of the prodrugs on rodent CT-26 cells than that of free ART. Animal studies also demonstrated the enhanced inhibitory efficacy of PEOz-PLA-PBAE-ART2 micelles on the growth of rodent xenograft tumor.

Conclusion

The pH-responsive artesunate polymer prodrugs are promising candidates for colon cancer adjuvant therapy.

Outcomes Among Minority Patients With Metastatic Colorectal Cancer in a Safety-net Health Care System

BACKGROUND

Metastatic colorectal cancer (CRC) outcomes continue to improve, but they vary significantly by race and ethnicity. We hypothesize that these disparities arise from unequal access to care.

MATERIALS AND METHODS

The Harris Health System (HHS) is an integrated health delivery network that provides medical care to the underserved, predominantly minority population of Harris County, Texas. As the largest HHS facility and an affiliate of Baylor College of Medicine's Dan L. Duncan Comprehensive Cancer Center, Ben Taub Hospital (BTH) delivers cancer care through multidisciplinary subspecialty that prioritize access to care, adherence to evidence-based clinical pathways, integration of supportive services, and mitigation of financial toxicity. We performed a retrospective analysis of minority patients diagnosed with and treated for metastatic CRC at BTH between January 2010 and December 2012. Kaplan-Meier survival curves were compared with survival curves from randomized control trials reported during that time period.

RESULTS

We identified 103 patients; 40% were black, 49% were Hispanic, and 12% were Asian or Middle Eastern. Thirty-five percent reported a language other than English as their preferred language. Seventy-four percent of patients with documented coverage status were uninsured. Eighty-four percent of patients received standard chemotherapy with a clinician-reported response rate of 63%. Overall survival for BTH patients undergoing chemotherapy was superior to that of subjects enrolled in the CRYSTAL (Cetuximab Combined with Irinotecan in First-Line Therapy for Metastatic Colorectal Cancer) trial (median, 24.0 vs. 19.9 months; P = .014).

CONCLUSION

HHS provides a health delivery infrastructure through which minority patients with socioeconomic challenges experience clinical outcomes comparable with highly selected patients enrolled in randomized control trials. Efforts to resolve CRC disparities should focus on improving access of at-risk populations to high-quality comprehensive cancer care.

Expression of CUEDC2 in colorectal cancer with different invasion and migration abilities

OBJECTIVE

To investigate CUE domain containing 2 ( CUEDC2) expression in colorectal cancer with different invasion and migration abilities.

METHODS

Fresh colon cancer tissues, obtained from patients with or without lymph node metastasis who were treated at the Department of General Surgery, Chinese People's Liberation Army General Hospital, and SW620 and HT29 colorectal cancer cell lines, were analysed for CUEDC2 expression.

RESULTS

Real-time polymerase chain reaction showed significantly higher CUEDC2 mRNA levels in colon cancer tissue from patients with ( n = 8) versus without ( n = 8) lymph node metastasis, and in SW620 versus HT29 cells. Western blots revealed significantly higher CUEDC2 protein levels in colon cancer tissues from patients with versus without lymph node metastasis, and in SW620 versus HT29 cells. Colorectal cancer tissues from patients with lymph node metastasis showed more intense immunohistochemical staining and moderate staining of cell nuclei and cytoplasm versus less intense/weak staining in tissues from patients without lymph node metastasis.

CONCLUSIONS

CUEDC2 is highly expressed in colorectal cancer tissues and colorectal cancer cell lines with high invasion and migration ability. CUEDC2 may be involved in promoting invasion and metastasis in colorectal cancer.

Leptomeningeal Carcinomatosis in Colorectal Cancer: The Mayo Clinic Experience

BACKGROUND

Leptomeningeal metastasis (LM) is an uncommon form of metastatic disease in many cancers. There remains a paucity of literature with regard to the course and management of LM in colorectal cancers (CRCs). The aim of this study was to estimate the incidence of LM in patients with CRC seen at our institution over a 15-year period, and to describe the clinical course and outcome of these cases.

METHODS

LM in CRC primary cases between 2000 and 2014 were identified in the Mayo Clinic databases. The charts were retrospectively reviewed.

RESULTS

Of 17,095 CRC primaries, we identified 10 patients with LM (0.058%) in this 15-year period. Nine cases were included in the analysis. Four had metastatic disease at the time of their initial CRC diagnosis. Median overall survival after CRC diagnosis was 25.7 months (range, 4.7-74.8 months). Median time to diagnosis of LM after CRC diagnosis was 25.3 months (range, 0-68.1 months). All patients had magnetic resonance imaging findings consistent with LM: 3 patients with spinal LM, 5 patients with intracranial LM, and 1 with both. Neurologic symptoms correlated with site of the lesions, with headache, cranial nerve palsy, lower extremity weakness, and gait disturbance among the most frequently reported. However, not all patients had neurologic findings, with LM lesions found incidentally in 2 cases. Seven patients (78%) had palliative radiotherapy for LM. Three patients continued to receive systemic chemotherapy after diagnosis of LM. Median survival after LM diagnosis was 7 weeks (range, 2-39 weeks).

CONCLUSIONS

LM is an exceedingly rare development in the natural course of CRC. It confers a poor prognosis with limited treatment options. At our institution, most patients had their disease addressed by palliative means, with many receiving radiotherapy to control their neurologic symptoms. Based on our series, supportive care remains a sensible approach to the management of LM in CRC.

A Novel Derivation Predicting Survival After Primary Tumor Resection in Stage IV Colorectal Cancer: Validation of a Prognostic Scoring Model and an Online Calculator to Provide Individualized Survival Estimation

BACKGROUND

A prognostic scoring model has been devised previously to predict survival following primary tumor resection in patients with metastatic colorectal cancer and unresectable metastases. This has yet to be validated.

OBJECTIVE

The main objectives of this study are to validate the proposed prognostic scoring model and create an interactive online calculator to estimate an individual's survival after primary tumor resection.

DESIGN

Clinical data and survival outcomes of patients were extracted from a prospectively maintained database. Patients were categorized into good, moderate, or poor survivor groups based on the previously proposed scoring algorithm. Discrimination was assessed and recalibration was performed, with the recalibrated model implemented as an interactive Web application to provide individualized survival probability.

SETTINGS

This study was conducted at a tertiary referral center.

PATIENTS

The study included 324 consecutive patients with metastatic colorectal carcinoma and unresectable metastases who underwent primary tumor resection between January 2008 and December 2013.

MAIN OUTCOME MEASURES

The primary outcome measured was overall survival.

RESULTS

Three hundred twenty-four patients were included in the study. Median survival in the good, moderate, and poor prognostic groups was 56.8, 25.7, and 19.9 months (log rank test, p = 0.003). The κ statistic was 0.638 and RD was 0.101. Significant differences in survival were found between the moderate and good prognostic groups (HR, 2.79; 95% CI, 1.51-5.15; p = 0.001) and between poor and good prognostic groups (HR, 4.12; 95% CI, 1.98-8.55; p < 0.001). The model was implemented as an interactive online calculator to provide individualized survival estimation after primary tumor resection (http://bit.ly/Stage4PrognosticScore).

LIMITATIONS

Selection bias and single-center data preclude the generalizability of the proposed model. Information regarding the severity or likelihood of developing symptoms from the primary tumor were also not accounted for in the prognostic scoring model proposed.

CONCLUSIONS

The prognostic scoring model provides good prognostic stratification of survival after primary tumor resection and may be a useful tool to predict survival after primary tumor resection. See Video Abstract at http://links.lww.com/DCR/A330.

Liver-directed therapy in metastatic colorectal cancer

INTRODUCTION

Colorectal cancer is a significant global health issue with over 1 million cases diagnosed annually throughout the world. 15% of patients diagnosed with colorectal cancer will have liver metastases and 60% will develop liver metastases if they have metastatic disease. Oligometastatic colorectal cancer confined to the liver represents an intermediate state in the evolution of metastatic capacity that opens the opportunity for local interventions. Areas covered: The literature supports long-term survival if patients undergo liver resection of colorectal metastases. This article reviews the liver-directed therapeutic strategies available for the management of metastatic liver disease including hepatic arterial infusion therapy, radiofrequency ablation, radiation therapy and transarterial chemoembolization. Expert commentary: Great advances have been made with the use of liver directed therapies. In the USA using hepatic arterial infusions with FUDR and Decadron along with systemic therapy, 5 year survivals after liver resection have improved. In Europe with the use of HAI of Oxaliplatin, more patients have been able to get to resection and have obtained higher survival rates, even in second line therapy. New advances in ablative therapy have improved results to get all disease treated at resection for the treatment of reccurrence.

Mutation location on the RAS oncogene affects pathologic features and survival after resection of colorectal liver metastases

BACKGROUND

In the past 3 decades, a better understanding of gene mutations and their role in carcinogenesis has led to improvement in our ability to treat patients with metastatic disease. The objective of the current study was to determine whether the location of a driver mutation within an affected gene impacts the biology of metastatic colorectal cancer.

METHODS

DNA was collected from 165 randomly selected specimens of patients who underwent margin-negative resection of colorectal liver metastases with curative intent. Sequenom analysis and Sanger sequencing were used to evaluate mutations in K/NRAS, PIK3CA, BRAF, and TP53.

RESULTS

BRAF mutation was associated with early recurrence and death, whereas no impact of TP53 or PIK3CA mutation was identified. Although K/NRAS mutation was associated with worse survival in this cohort, this difference was no longer evident when those who had received anti-EGFR therapy were excluded. When stratifying patients according to the exon on which K/NRAS was mutated, there were dramatic differences in both survival and pathologic features. Exon 4 mutations were associated with large, solitary metastases occurring at long disease-free intervals compared with exon 3 mutations, which presented with small, numerous lesions. Patients who had exon 4 mutations recurred infrequently and had significantly longer survival compared with those who had wild type or other mutations.

CONCLUSIONS

By using this model of curative-intent, margin-negative resection in patients at high risk of recurrence, the authors were able to establish a link between mutation location within the K/NRAS gene and the biology of metastatic colorectal cancer. Cancer 2017;123:568-575. © 2016 American Cancer Society.

Molecular profiling of cetuximab and bevacizumab treatment of colorectal tumours reveals perturbations in metabolic and hypoxic response pathways

Angiogenesis and epidermal growth factor receptor (EGFR) inhibition has been shown to have anti-tumour efficacy, and enhance the therapeutic effects of cytotoxic chemotherapy in metastatic colorectal cancer. The interplay of signalling alterations and changes in metabolism and hypoxia in tumours following anti-VEGF and anti-EGFR treatment is not well understood. We aimed to explore the pharmacodynamics of cetuximab and bevacizumab treatment in human colon carcinoma tumour cells in vitro and xenograft models through proteomic profiling, molecular imaging of metabolism and hypoxia, and evaluation of therapy-induced changes in tumour cells and the tumour microenvironment. Both cetuximab and bevacizumab inhibited tumour growth in vivo, and this effect was associated with selectively perturbed glucose metabolism and reduced hypoxic volumes based on PET/MRI imaging. Global proteomic profiling of xenograft tumours (in presence of cetuximab, bevacizumab, and combination treatments) revealed alterations in proteins involved in glucose, lipid and fatty acid metabolism (e.g., GPD2, ATP5B, STAT3, FASN), as well as hypoxic regulators and vasculogenesis (e.g., ATP5B, THBS1, HSPG2). These findings correlated with western immunoblotting (xenograft lysates) and histological examination by immunohistochemistry. These results define important mechanistic insight into the dynamic changes in metabolic and hypoxic response pathways in colorectal tumours following treatment with cetuximab and bevacizumab, and highlight the ability of these therapies to selectively impact on tumour cells and extracellular microenvironment.

Intra-patient Inter-metastatic Genetic Heterogeneity in Colorectal Cancer as a Key Determinant of Survival after Curative Liver Resection

Chromosomal instability is a well-defined hallmark of tumor aggressiveness and metastatic progression in colorectal cancer. The magnitude of genetic heterogeneity among distinct liver metastases from the same patient at the copy number level, as well as its relationship with chemotherapy exposure and patient outcome, remains unknown. We performed high-resolution DNA copy number analyses of 134 liver metastatic deposits from 45 colorectal cancer patients to assess: (i) intra-patient inter-metastatic genetic heterogeneity using a heterogeneity score based on pair-wise genetic distances among tumor deposits; and (ii) genomic complexity, defined as the proportion of the genome harboring aberrant DNA copy numbers. Results were analyzed in relation to the patients' clinical course; previous chemotherapy exposure and outcome after surgical resection of liver metastases. We observed substantial variation in the level of intra-patient inter-metastatic heterogeneity. Heterogeneity was not associated with the number of metastatic lesions or their genomic complexity. In metachronous disease, heterogeneity was higher in patients previously exposed to chemotherapy. Importantly, intra-patient inter-metastatic heterogeneity was a strong prognostic determinant, stronger than known clinicopathological prognostic parameters. Patients with a low level of heterogeneity (below the median level) had a three-year progression-free and overall survival rate of 23% and 66% respectively, versus 5% and 18% for patients with a high level (hazard ratio0.4, 95% confidence interval 0.2-0.8, P = 0.01; and hazard ratio0.3,95% confidence interval 0.1-0.7, P = 0.007). A low patient-wise level of genomic complexity (below 25%) was also a favorable prognostic factor; however, the prognostic association of intra-patient heterogeneity was independent of genomic complexity in multivariable analyses. In conclusion, intra-patient inter-metastatic genetic heterogeneity is a pronounced feature of metastatic colorectal cancer, and the strong prognostic association reinforces its clinical relevance and places it as a key feature to be explored in future patient cohorts.

The Preoperative Peripheral Blood Monocyte Count Is Associated with Liver Metastasis and Overall Survival in Colorectal Cancer Patients

Background

Colorectal cancer (CRC) is the third most common malignancy in males and the second most common in females worldwide. Distant metastases have a strong negative impact on the prognosis of CRC patients. The most common site of CRC metastases is the liver. Both disease progression and metastasis have been related to the patient’s peripheral blood monocyte count. We therefore performed a case-control study to assess the relationship between the preoperative peripheral blood monocyte count and colorectal liver metastases (CRLM).

Methods

Clinical data from 117 patients with colon cancer and 93 with rectal cancer who were admitted to the Chinese People’s Liberation Army General Hospital (Beijing, China) between December 2003 and May 2015 were analysed retrospectively, with the permission of both the patients and the hospital.

Results

Preoperative peripheral blood monocyte counts, the T and N classifications of the primary tumour and its primary site differed significantly between the two groups (P < 0.001, P < 0.001, P = 0.002, P < 0.001), whereas there were no differences in the sex, age, degree of tumour differentiation or largest tumour diameter. Lymph node metastasis and a high preoperative peripheral blood monocyte count were independent risk factors for liver metastasis (OR: 2.178, 95%CI: 1.148~4.134, P = 0.017; OR: 12.422, 95%CI: 5.076~30.398, P < 0.001), although the risk was lower in patients with rectal versus colon cancer (OR: 0.078, 95%CI: 0.020~0.309, P < 0.001). Primary tumour site (P<0.001), degree of tumour differentiation (P = 0.009), T, N and M classifications, TNM staging and preoperative monocyte counts (P<0.001) were associated with the 5-year overall survival (OS) of CRC patients. A preoperative peripheral blood monocyte count > 0.505 × 10⁹ cells/L, high T classification and liver metastasis were independent risk factors for 5-year OS (RR: 2.737, 95% CI: 1.573~ 4.764, P <0.001; RR: 2.687, 95%CI: 1.498~4.820, P = 0.001; RR: 4.928, 95%CI: 2.871~8.457, P < 0.001).

Conclusions

The demonstrated association between preoperative peripheral blood monocyte count and liver metastasis in patients with CRC recommends the former as a useful predictor of postoperative prognosis in CRC patients.

Targeted delivery of small interfering RNA to colon cancer cells using chitosan and PEGylated chitosan nanoparticles

Small interfering RNA (siRNA) molecules specifically target messenger RNA species, decreasing intracellular protein levels. β-Catenin protein concentrations are increased in 70-80% of colon tumors, promoting tumor progression. Chitosan exhibits low levels of toxicity and can be transported across mucosal membranes; therefore, our objective was to develop chitosan and poly(ethylene glycol)-grafted (PEGylated) chitosan nanoparticles, 100-150nm in diameter, encapsulating anti-β-catenin siRNA for transfection into colon cancer cells. Encapsulation efficiencies up to 97% were observed. Confocal microscopy visualized the entry of fluorescently-tagged siRNA into cells. Western blot analysis showed that both chitosan and PEGylated chitosan nanoparticles containing anti-β-catenin siRNA decreased β-catenin protein levels in cultured colon cancer cells. These results indicate that nanoparticles made with chitosan and PEGylated chitosan can successfully enter colon cancer cells and decrease the level of a protein that promotes tumor progression. These or similar nanoparticles may prove beneficial for the treatment of colon cancer in humans.

Regression of Stage IV Pancreatic Cancer to Curative Surgery and Introduction of a Novel Ex-Vivo Chemosensitivity Assay

Although data suggests little hope for survival when patients present with metastatic pancreatic cancer, recent advances in systemic therapy offer the possibility for dramatic tumor responses like those observed in other disease sites. Here, we present the case of a 50-year-old woman who presented with adenocarcinoma of the pancreas with two liver metastases and a CA 19-9 level of 1,659 U/mL. The patient received FOLFIRINOX (leucovorin, 5-fluorouracil, irinotecan, and oxaliplatin) with a dramatic reduction in CA 19-9 level to 23.9 U/mL, and complete regression of both liver metastases. The patient then received capecitabine with the maintenance of a normal CA19-9 over the next 12 months. With no evidence of distant disease, concurrent systemic and local therapy with capecitabine-based chemoradiation (CapeXRT) was performed followed by observation for eight months with normal CA 19-9 readings. A mild increase in CA 19-9 (143 U/mL) prompted a restaging demonstrating an active primary tumor but no distant disease. Therefore, a pancreaticoduodenectomy (PD or Whipple) was performed rendering this patient free of detectable cancer.

Our team has developed an ex-vivo chemosensitivity assay in which the tumor tissue from an individual patient can be rapidly examined for sensitivity to available systemic therapy treatment strategies. We tested this patient’s tumor for its sensitivity to gemcitabine (Gem) versus a combination of 5-fluorouracil, irinotecan, and oxaliplatin (FIRINOX). Remarkably, our assay confirmed a profound sensitivity of this patient’s tumor to the agents she had received.

A metastatic colon adenocarcinoma harboring BRAF V600E has a durable major response to dabrafenib/trametinib and chemotherapy

The subset of metastatic colorectal adenocarcinomas that harbor BRAF V600E mutations are aggressive tumors with significantly shortened survival and limited treatment options. Here we present a colorectal cancer patient whose disease progressed through standard chemotherapy and who developed liver metastasis. Comprehensive genomic profiling (FoundationOne^®) identified a BRAF V600E mutation in the liver lesion, as well as other genomic alterations consistent with colorectal cancers. Combination therapy of dabrafenib and trametinib with standard cytotoxic chemotherapy resulted in a durable major ongoing response for the patient. This report illustrates the utility of comprehensive genomic profiling with personalized targeted therapy for aggressive metastatic colorectal adenocarcinomas.

TroVax in colorectal cancer

Currently, the backbone of therapy for metastatic disease is cytotoxic chemotherapy, along with the recent addition of targeted therapy based on molecular markers with KRAS testing. Despite the improvement in survival for metastatic colon cancer, newer agents are still needed. The clinical activity of TroVax in metastatic colon cancer has been studied in a small number of clinical trials. There is evidence that supports the vaccine's ability to induce humoral and cellular responses, as demonstrated by positive 5T4 and MVA-specific antibody titers and cellular proliferation assays. Future strategies should focus on investigating the immunomodulatory effects of chemotherapy in conjunction with TroVax, understanding the optimal dosing and schedule of the combination, and examining potential predictive biomarkers to determine which patients may benefit from immunotherapy from those who do not.

Durable clinical benefit to trastuzumab and chemotherapy in a patient with metastatic colon adenocarcinoma harboring ERBB2 amplification

Somatic ERBB2 amplification or activating mutations occur in approximately 2-5% of metastatic colorectal adenocarcinomas and are presumed to be oncogenic drivers, but limited evidence exists to suggest these lesions are sensitive to targeted monotherapy in patients. Here we present the case of a patient with advanced CRC with pulmonary metastases, who had progressed on both standard of care cytotoxic chemotherapy and anti-EGFR targeted therapy. Comprehensive genomic profiling (FoundationOne(®)) identified amplification of ERBB2 and a TP53 mutation in the metastatic lesion. Treatment with trastuzumab with a chemotherapy backbone elicited stable disease/minor response in the patient over a one year course of therapy, reducing tumor burden and significantly improving quality of life. This report demonstrates the application of personalized targeted therapy guided by comprehensive genomic profiling in metastatic colorectal adenocarcinoma.

Hospital academic status and value of care for nonmetastatic colon cancer

PURPOSE

The relationship between oncologic hospital academic status and the value of care for stage II and III colon cancer is unknown.

METHODS

Retrospective SEER-Medicare analysis of patients age ≥ 66 years with stage II or III colon cancer and seen by medical oncology. Eligible patients were diagnosed 2000 to 2009 and followed through December 31, 2010. Hospitals reporting a major medical school affiliation in the NCI Hospital File were classified as academic medical centers. The association between hospital academic status and survival was assessed using Kaplan-Meier curves and Cox proportional hazards models. The association with mean cost of care was estimated using generalized linear models with log link and gamma family and with cost of care at various quantiles using quantile regression models.

RESULTS

Of 24,563 eligible patients, 5,707 (23%) received care from academic hospitals. There were no significant differences in unadjusted disease-specific median survival or adjusted risk of colon cancer death by hospital academic status (stage II hazard ratio = 1.12; 95% CI, 0.98 to 1.28; P = .103; stage III hazard ratio = 0.99; 95% CI, 0.90 to 1.08; P = .763). Excepting patients at the upper limits of the cost distribution, there was no significant difference in adjusted cost by hospital academic status.

CONCLUSION

We found no survival differences for elderly patients with stage II or III colon cancer, treated by a medical oncologist, between academic and nonacademic hospitals. Furthermore, cost of care was similar across virtually the full range of the cost distribution.

Monosegment ALPPS: A new variant of the techniques for rapid hepatic regeneration. Critical review of the initial results of our series

Associating Liver Partition and Portal vein ligation for Staged hepatectomy (ALPPS) is a novel surgical technique that provides fast and effective growth of liver remnant volume, allowing surgical resection of hepatic lesions initially considered unresectable. Short and long-term results and the convenience of carrying out this technique are issues that still remain under debate while waiting for the final outcomes of the multicenter registries with larger number of cases. The aim of this paper is to describe, from a critical point of view, the outcomes of the cases performed at our center (n=8). On the other hand, it is possible to leave only one hepatic segment as a liver remnant and we illustrate this new surgical procedure (ALPPS monosegment) performed in one patient.

Blockade of EGFR and MEK intercepts heterogeneous mechanisms of acquired resistance to anti-EGFR therapies in colorectal cancer

Colorectal cancers (CRCs) that are sensitive to the anti-epidermal growth factor receptor (EGFR) antibodies cetuximab or panitumumab almost always develop resistance within several months of initiating therapy. We report the emergence of polyclonal KRAS, NRAS, and BRAF mutations in CRC cells with acquired resistance to EGFR blockade. Regardless of the genetic alterations, resistant cells consistently displayed mitogen-activated protein kinase kinase (MEK) and extracellular signal-regulated kinase (ERK) activation, which persisted after EGFR blockade. Inhibition of MEK1/2 alone failed to impair the growth of resistant cells in vitro and in vivo. An RNA interference screen demonstrated that suppression of EGFR, together with silencing of MEK1/2, was required to hamper the proliferation of resistant cells. Indeed, concomitant pharmacological blockade of MEK and EGFR induced prolonged ERK inhibition and severely impaired the growth of resistant tumor cells. Heterogeneous and concomitant mutations in KRAS and NRAS were also detected in plasma samples from patients who developed resistance to anti-EGFR antibodies. A mouse xenotransplant from a CRC patient who responded and subsequently relapsed upon EGFR therapy showed exquisite sensitivity to combinatorial treatment with MEK and EGFR inhibitors. Collectively, these results identify genetically distinct mechanisms that mediate secondary resistance to anti-EGFR therapies, all of which reactivate ERK signaling. These observations provide a rational strategy to overcome the multifaceted clonal heterogeneity that emerges when tumors are treated with targeted agents. We propose that MEK inhibitors, in combination with cetuximab or panitumumab, should be tested in CRC patients who become refractory to anti-EGFR therapies.

MicroRNA-320b promotes colorectal cancer proliferation and invasion by competing with its homologous microRNA-320a

Colorectal cancer metastasis is believed to be associated with microRNA dysregulation. However, little is known as to how microRNAs regulate colorectal cancer proliferation, invasion and metastasis. In the present study, we compared the microRNA expression profiles between patients of colorectal cancer at diagnosis with and without liver metastasis. MicroRNA-320b was found to be among those up-regulated in the patient group with metastasis. We subsequently found that microRNA-320b, opposite of its homolog, microRNA-320a that differs by only a single nucleotide, functions in promoting colorectal cancer cell proliferation and invasion. Moreover, we found that overexpression of exogenous microRNA-320b can up-regulate the target genes of microRNA-320a including β-catenin, Neuropilin-1 and Rac-1, which are all known to promote tumor proliferation, invasion and metastasis. These results suggest that microRNA-320b may function in competing with microRNA-320a. Thus, our study has proposed one novel mechanism for controlling colorectal cancer proliferation and invasion through homologous competition between microRNAs. This mechanism may be important for colorectal cancer metastasis.

A phase II, randomized, double blind trial of calcium aluminosilicate clay versus placebo for the prevention of diarrhea in patients with metastatic colorectal cancer treated with irinotecan

PURPOSE

Calcium aluminosilicate clay (CASAD) is a naturally occurring clay that serves as a cation exchange absorbent. We hypothesized that oral administration of CASAD would reduce the rate of grade 3/4 diarrhea associated with irinotecan use for metastatic colorectal cancer (CRC) by adsorbing the SN-38 metabolite.

METHODS

Patients receiving irinotecan-based chemotherapy were randomized equally between CASAD and placebo arms in this multicenter trial in order to assess differences in the proportions of patients with grade 3/4 diarrhea within 6 weeks. Additionally, we compared symptom severity between the two arms using the M.D. Anderson Symptom Inventory.

RESULTS

Between May 2009 and May 2012, 100 patients were enrolled. In evaluable patients, 7 of 43 (16 %) on the CASAD arm compared to 3 of 32 (9 %) on the placebo arm experienced grade 3/4 diarrhea (P = 0.70). The rate of any diarrhea among all patients was similar (CASAD arm, 64 % vs. placebo arm, 70 %). The rate of study dropout was 14 % in the CASAD arm and 38 % in the placebo arm (P = 0.01). No differences were found in symptom severity, individual symptom items, and in serious adverse events between the two arms.

CONCLUSION

Compared to placebo, CASAD use was safe but ineffective in preventing diarrhea in metastatic CRC patients treated with irinotecan-containing chemotherapy regimens. There were no distinct signals in terms of patient symptoms between arms, but there was significantly more patient dropout in the placebo arm. Future CASAD trials will focus on the active treatment of diarrhea.

Patients' experiences of ongoing palliative chemotherapy for metastatic colorectal cancer: a qualitative study

BACKGROUND

Colorectal cancer is the second most common cause of cancer death in New Zealand. With new chemotherapy regimens, patients with metastatic colorectal cancer are now living longer with the condition and its treatment.

AIM

This study aimed to explore patients' experiences of extended palliative chemotherapy for metastatic colorectal cancer.

METHODS

A convenience sample of 10 outpatients who had been receiving palliative chemotherapy for more than 12 months from a teaching hospital and regional cancer centre in New Zealand participated in face-to-face semi-structured interviews. The data was analysed using a general inductive approach.

FINDINGS

Three key themes were identified: the importance of relationships, presenting a positive face, and life is for living. The importance of interpersonal relationships with health professionals and a sense of comradery with other chemotherapy patients positively affected the patients' experiences of treatment. Positivity was a key coping strategy that also has negative implications as patients may not reveal their concerns and needs.

CONCLUSION

The key to improving the care of people with advanced cancer is understanding their experiences of care. Communication between the patient, family, and health-care team ensures assumptions that misinterpret attributes of positivity are not made.

The effect of care setting in the delivery of high-value colon cancer care

BACKGROUND

The effect of care setting on value of colon cancer care is unknown.

METHODS

A Surveillance, Epidemiology, and End Results (SEER)-Medicare cohort study of 6544 patients aged ≥ 66 years with stage IV colon cancer (based on the American Joint Committee on Cancer staging system) who were diagnosed between 1996 and 2005 was performed. All patients were followed through December 31, 2007. Using outpatient and carrier claims, patients were assigned to a treating hospital based on the hospital affiliation of the primary oncologist. Hospitals were classified academic or nonacademic using the SEER-Medicare National Cancer Institute Hospital File.

RESULTS

Of the 6544 patients, 1605 (25%) received care from providers affiliated with academic medical centers. The unadjusted median cancer-specific survival was 16.0 months at academic medical centers versus 13.9 months at nonacademic medical centers (P < .001). After adjustment, treatment at academic hospitals remained significantly associated with a reduced risk of death from cancer (hazard ratio, 0.87; 95% confidence interval [95% CI], 0.82-0.93 [P < .001]). Adjusted mean 12-month Medicare spending was $8571 higher at academic medical centers (95% CI, $2340-$14,802; P = .007). The adjusted median cost was $1559 higher at academic medical centers; this difference was not found to be statistically significant (95% CI, -$5239 to $2122; P = .41). A small percentage of patients who received very expensive care skewed the difference in mean cost; the only statistically significant difference in adjusted costs in quantile regressions was at the 99.9th percentile of costs (P < .001).

CONCLUSIONS

Among Medicare beneficiaries with stage IV colon cancer, treatment by a provider affiliated with an academic medical center was associated with a 2 month improvement in overall survival. Except for patients in the 99.9th percentile of the cost distribution, costs at academic medical centers were not found to be significantly different from those at nonacademic medical centers.

Epidermal growth factor receptor: pathway, therapies, and pipeline

BACKGROUND

The epidermal growth factor receptor (EGFR) pathway is important in tumor growth, survival, and metastasis and is now the target of several therapeutic agents.

OBJECTIVES

This paper seeks to review the EGFR pathway, the study and use of EGFR-directed agents in non-small-cell lung cancer (NSCLC) and colorectal cancer (CRC), and related new drug development.

METHODS

PubMed was searched for English-language articles by MeSH and title terms of EGFR published from 2006 to 2013, using the limits of clinical trials as well as reviews. Reference lists were assessed for relevant articles, and guidelines were searched. Clinicaltrials.gov and meeting abstracts were queried for investigational agents. Eligible papers included those concerning EGFR biology, NSCLC or CRC studies involving EGFR-directed agents, and/or investigational drugs targeting EGFR and/or associated pathways.

RESULTS

The activity of oral tyrosine kinase inhibitors (TKIs) against EGFR has improved survival in NSCLC, and these agents particularly effective in cancers with an EGFR mutation. Resistance to TKIs is most commonly related to a second, T790M, mutation, or to MET amplification, with newer agents directed against these mechanisms. Conversely, in CRC, TKIs have been ineffective, whereas monoclonal antibodies have improved survival. Both primary and secondary KRAS mutations in CRC abrogate mAb effectiveness. Several targets, including MET, BRAF, and PI3K, may serve useful in combination with anti-EGFR drugs.

CONCLUSIONS

Exploitation of EGFR-directed therapies has offered improvement in survival and quality of life in NSCLC and CRC. New therapies directed at EGFR may offer further improvements. However, resistance mechanisms suggest that combination therapies or multitargeted agents will be crucial in making significant future advances.