Common variation near CDKN1A, POLD3 and SHROOM2 influences colorectal cancer risk

We performed a meta-analysis of five genome-wide association studies to identify common variants influencing colorectal cancer (CRC) risk comprising 8,682 cases and 9,649 controls. Replication analysis was performed in case-control sets totaling 21,096 cases and 19,555 controls. We identified three new CRC risk loci at 6p21 (rs1321311, near CDKN1A; P = 1.14 × 10(-10)), 11q13.4 (rs3824999, intronic to POLD3; P = 3.65 × 10(-10)) and Xp22.2 (rs5934683, near SHROOM2; P = 7.30 × 10(-10)) This brings the number of independent loci associated with CRC risk to 20 and provides further insight into the genetic architecture of inherited susceptibility to CRC.

EnROL: a multicentre randomised trial of conventional versus laparoscopic surgery for colorectal cancer within an enhanced recovery programme

BACKGROUND

During the last two decades the use of laparoscopic resection and a multimodal approach known as an enhanced recovery programme, have been major changes in colorectal perioperative care. Clinical outcome improves using laparoscopic surgery to resect colorectal cancer but until recently no multicentre trial evidence had been reported regarding whether the benefits of laparoscopy still exist when open surgery is optimized within an enhanced recovery programme. The EnROL trial (Enhanced Recovery Open versus Laparoscopic) examines the hypothesis that laparoscopic surgery within an enhanced recovery programme will provide superior postoperative outcomes when compared to conventional open resection of colorectal cancer within the same programme.

METHODS/DESIGN

EnROL is a phase III, multicentre, randomised trial of laparoscopic versus open resection of colon and rectal cancer with blinding of patients and outcome observers to the treatment allocation for the first 7 days post-operatively, or until discharge if earlier. 202 patients will be recruited at approximately 12 UK hospitals and randomised using minimization at a central computer system in a 1:1 ratio. Recruiting surgeons will previously have performed >100 laparoscopic colorectal resections and >50 open total mesorectal excisions to minimize conversion. Eligible patients are those suitable for elective resection using either technique. Excluded patients include: those with acute intestinal obstruction and patients in whom conversion from laparoscopic to open procedure is likely. The primary outcome is physical fatigue as measured by the physical fatigue domain of the multidimensional fatigue inventory 20 (MFI-20) with secondary outcomes including postoperative hospital stay; complications; reoperation and readmission; quality of life indicators; cosmetic assessments; standardized performance indicators; health economic analysis; the other four domains of the MFI-20. Pathological assessment of surgical quality will also be undertaken and compliance with the enhanced recovery programme will be recorded for all patients.

DISCUSSION

Should this trial demonstrate that laparoscopic surgery confers a significant clinical and/or health economic benefit this will further support the transition to this type of surgery, with implications for the training of surgeons and resource allocation.

TRIAL REGISTRATION

ISRCTN48516968.

ES5-3: Novel Approaches to Breast Cancer Management in Low-Income Countries

There is clear evidence that the global burden of cancer is increasingly affecting low and middle - income countries, effectively those nations who have least health infrastructure to deal with complex diseases like cancer. A new approach to cancer therapy is required that combines efficacy, reduced side effects, cost-effectiveness with a delivery mechanism that does not rely on access to distant and expensive regional cancer centres. To this end we propose to develop a combination oral chemotherapy formulation which is likely to offer a clinically useful advantage to patients suffering from breast cancer For almost half a century, systemic therapy of cancer has been dominated by the use of cytotoxic chemotherapeutics. Most of these drugs are DNA damaging agents or microtubule inhibitors that are designed to inhibit or kill rapidly dividing cells, often administered in single doses or short courses of therapy at the highest doses possible, with prolonged breaks (generally of 2–3 weeks in duration) between successive cycles of therapy. A reappraisal of the optimal way of administering chemotherapy is underway. Instead of using short bursts of toxic chemotherapy interspersed with long breaks to allow recovery from the harmful side effects, there is now a shift in thinking towards the view that more chronic or decelerated schedules of drug administration using much smaller individual doses than the MTD may be more effective — not only in terms of reducing certain toxicities, but perhaps also improving anti-tumour efficacy with an additional anti-endothelial cell effect, so-called ‘metronomic’ chemotherapy. We propose development of a flat dose, combination, oral chemotherapy formulation which will contain the following classes of antineoplastic agents, which have been shown to have activity in breast cancer. Fluoropyrimidines eg Capecitabine; Alkylating Agents eg Cyclophosphamide; Antiemetics eg Metoclopramide; administered continuously at doses inducing Grade 1 toxicity.

The drug doses will be carefully selected to provide moderately effective cancer control with reduced toxicity profiles. The clinical development pathway will be conducted in India and SubSaharan Africa with a view to providing a managed package of care which will allow delivery of the MetroPill to women with breast cancer in rural and minor urban settings rather than the regional cancer centres. We will train a cohort of district general hospital doctors/nurses to monitor and deliver the MetroPill, supported by a teaching package app and mobile phone technology to provide symptom support for patients. A phase 1 feasibility and pharmacokinetic study will be performed in 20–30 patients followed by single arm Phase 2 studies(n=40 patients) in breast cancer patients, which will report response rates, progression free survival and quality of life as a prelude to phase 3 trials. We believe that this is the sort of lateral approach we must consider if we are to take elements of cancer therapy to those regions which lie beyond the shadow of conventional cancer centres.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr ES5-3.

Refinement of the associations between risk of colorectal cancer and polymorphisms on chromosomes 1q41 and 12q13.13

In genome-wide association studies (GWASs) of colorectal cancer, we have identified two genomic regions in which pairs of tagging-single nucleotide polymorphisms (tagSNPs) are associated with disease; these comprise chromosomes 1q41 (rs6691170, rs6687758) and 12q13.13 (rs7163702, rs11169552). We investigated these regions further, aiming to determine whether they contain more than one independent association signal and/or to identify the SNPs most strongly associated with disease. Genotyping of additional sample sets at the original tagSNPs showed that, for both regions, the two tagSNPs were unlikely to identify a single haplotype on which the functional variation lay. Conversely, one of the pair of SNPs did not fully capture the association signal in each region. We therefore undertook more detailed analyses, using imputation, logistic regression, genealogical analysis using the GENECLUSTER program and haplotype analysis. In the 1q41 region, the SNP rs11118883 emerged as a strong candidate based on all these analyses, sufficient to account for the signals at both rs6691170 and rs6687758. rs11118883 lies within a region with strong evidence of transcriptional regulatory activity and has been associated with expression of PDGFRB mRNA. For 12q13.13, a complex situation was found: SNP rs7972465 showed stronger association than either rs11169552 or rs7136702, and GENECLUSTER found no good evidence for a two-SNP model. However, logistic regression and haplotype analyses supported a two-SNP model, in which a signal at the SNP rs706793 was added to that at rs11169552. Post-GWAS fine-mapping studies are challenging, but the use of multiple tools can assist in identifying candidate functional variants in at least some cases.

Validation study of a quantitative multigene reverse transcriptase-polymerase chain reaction assay for assessment of recurrence risk in patients with stage II colon cancer

PURPOSE

We developed quantitative gene expression assays to assess recurrence risk and benefits from chemotherapy in patients with stage II colon cancer.

PATIENTS AND METHODS

We sought validation by using RNA extracted from fixed paraffin-embedded primary colon tumor blocks from 1,436 patients with stage II colon cancer in the QUASAR (Quick and Simple and Reliable) study of adjuvant fluoropyrimidine chemotherapy versus surgery alone. A recurrence score (RS) and a treatment score (TS) were calculated from gene expression levels of 13 cancer-related genes (n = 7 recurrence genes and n = 6 treatment benefit genes) and from five reference genes with prespecified algorithms. Cox proportional hazards regression models and log-rank methods were used to analyze the relationship between the RS and risk of recurrence in patients treated with surgery alone and between TS and benefits of chemotherapy.

RESULTS

Risk of recurrence was significantly associated with RS (hazard ratio [HR] per interquartile range, 1.38; 95% CI, 1.11 to 1.74; P = .004). Recurrence risks at 3 years were 12%, 18%, and 22% for predefined low, intermediate, and high recurrence risk groups, respectively. T stage (HR, 1.94; P < .001) and mismatch repair (MMR) status (HR, 0.31; P < .001) were the strongest histopathologic prognostic factors. The continuous RS was associated with risk of recurrence (P = .006) beyond these and other covariates. There was no trend for increased benefit from chemotherapy at higher TS (P = .95).

CONCLUSION

The continuous 12-gene RS has been validated in a prospective study for assessment of recurrence risk in patients with stage II colon cancer after surgery and provides prognostic value that complements T stage and MMR. The TS was not predictive of chemotherapy benefit.

Challenges of cancer control in developing countries: current status and future perspective

Cancer is a global problem accounting for almost 13% of all deaths worldwide. This equates to over 7 million people a year, more than is caused by HIV/AIDS, TB and malaria combined. Now is the time to strengthen the health systems of developing countries to deal with cancer, to avoid a future crisis similar to the HIV/AIDS pandemic. In this article we discuss the current state of cancer in the developing world, how we need to advocate for a change in cancer control policy with the governments of developing nations/transnational governmental bodies (e.g., the UN and WHO etc) and how we think cancer care could be improved in developing countries. We feel the only way to overcome the growing burden of cancer in the developing world is working in partnership with, nongovernmental organizations, international nongovernmental organizations, transnational governmental bodies and governmental bodies.

Documenting the natural history of patients with resected stage II adenocarcinoma of the colon after random assignment to adjuvant treatment with edrecolomab or observation: results from CALGB 9581

PURPOSE

We conducted a randomized trial comparing adjuvant treatment with edrecolomab versus observation in patients with resected, low-risk, stage II colon cancer. This study also prospectively studied patient- and tumor-specific markers of treatment outcome.

PATIENTS AND METHODS

After surgical resection, patients with stage II colon cancer were randomly assigned to either five infusions of edrecolomab at 28-day intervals or observation without adjuvant therapy.

RESULTS

Final accrual included 1,738 patients; 865 patients received edrecolomab, and 873 patients were observed without adjuvant treatment. Median follow-up time was 7.9 years. There were no significant outcome differences between study arms (overall survival [OS], P = .71; disease-free survival, P = .64). The combined 5-year all-cause OS was 0.86 (95% CI, 0.84 to 0.88), and the combined 5-year disease-specific OS was 0.93 (95% CI, 0.91 to 0.94). The relationships between demographic and histopathologic factors and survival differed for all-cause and disease-specific survival outcomes, but no combined prognostic factor model was found to adequately classify patients at higher risk of recurrence or death as a result of colon cancer.

CONCLUSION

Edrecolomab did not prolong survival. Consequently, this large study with a long duration of follow-up provided unique data concerning the natural history of resected stage II colon cancer. Prognostic factors identified in previous retrospective and pooled analyses were associated with survival outcomes in this stage II patient cohort. Results from ongoing molecular marker studies may enhance our ability to determine the risk profile of these patients.

Multiple common susceptibility variants near BMP pathway loci GREM1, BMP4, and BMP2 explain part of the missing heritability of colorectal cancer

Genome-wide association studies (GWAS) have identified 14 tagging single nucleotide polymorphisms (tagSNPs) that are associated with the risk of colorectal cancer (CRC), and several of these tagSNPs are near bone morphogenetic protein (BMP) pathway loci. The penalty of multiple testing implicit in GWAS increases the attraction of complementary approaches for disease gene discovery, including candidate gene- or pathway-based analyses. The strongest candidate loci for additional predisposition SNPs are arguably those already known both to have functional relevance and to be involved in disease risk. To investigate this proposition, we searched for novel CRC susceptibility variants close to the BMP pathway genes GREM1 (15q13.3), BMP4 (14q22.2), and BMP2 (20p12.3) using sample sets totalling 24,910 CRC cases and 26,275 controls. We identified new, independent CRC predisposition SNPs close to BMP4 (rs1957636, P = 3.93×10(-10)) and BMP2 (rs4813802, P = 4.65×10(-11)). Near GREM1, we found using fine-mapping that the previously-identified association between tagSNP rs4779584 and CRC actually resulted from two independent signals represented by rs16969681 (P = 5.33×10(-8)) and rs11632715 (P = 2.30×10(-10)). As low-penetrance predisposition variants become harder to identify-owing to small effect sizes and/or low risk allele frequencies-approaches based on informed candidate gene selection may become increasingly attractive. Our data emphasise that genetic fine-mapping studies can deconvolute associations that have arisen owing to independent correlation of a tagSNP with more than one functional SNP, thus explaining some of the apparently missing heritability of common diseases.

Quinone oxidoreductase-2-mediated prodrug cancer therapy

DNA-damaging agents are widely used in cancer treatment despite their lack of tumor specificity. Human NQO2 (quinone oxidoreductase-2) is an atypical oxidoreductase because no endogenous electron donor has been identified to date. The enzyme converts CB1954 [5-(aziridin-1-yl)-2,4-dinitrobenzamide], in the presence of the synthetic nicotinamide cofactor analog EP0152R, to a cytotoxic bifunctional alkylating agent. NQO2 activity in hepatocellular tumor tissue is higher than that in other cancer types by a factor of 6 and higher than that in bone marrow by a factor of 20. Structural data from x-ray crystallography and nuclear magnetic resonance spectroscopy allowed us to construct a model of CB1954 and EP0152R binding to NQO2, which suggested an optimal infusion schedule for a phase I trial combining the two agents. Thirty-two patients were treated, and diarrhea and serum transaminase concentrations defined a maximum tolerated dose for the drug combination. There was a clear pharmacokinetic interaction, with EP0152R inducing a marked increase in clearance of CB1954, in keeping with model predictions. We detected DNA interstrand cross-links caused by nitroreduced CB1954 in tumor biopsies from treated patients, demonstrating that the activated prodrug exerts its cytotoxic properties through DNA base alkylation.

Roles of tetrahydrobiopterin in promoting tumor angiogenesis

Nitric oxide (NO), which is derived from endothelial NO synthase (eNOS), provides crucial signals for angiogenesis in the tumor microenvironment. Tetrahydrobiopterin (BH4) is an absolute requirement for eNOS activity. In this study, we investigated whether this activation is both maintained by a wild-type Ras/phosphatidylinositol 3-kinase (PI3K)/Akt-positive feedback loop in endothelial cells and affects tumor angiogenesis. We found that supplementation of BH4 (via the pterin salvage pathway with Sep) increased Akt/eNOS phosphorylation in both human eNOS-transfected COS-7 cells and endothelial cells concomitant with increases in NO production, cell proliferation, migration, and tube formation. This augmentation was abrogated by a PI3K inhibitor. Sepiapterin (Sep) also increased GTP-bound wild-type Ras and PI3K/Akt/eNOS activation, which was prevented by the eNOS inhibitor, Nω-Nitro-L-arginine methyl ester (L-NAME). Furthermore, expression of GTP cyclohydrolase I (the rate-limiting enzyme in de novo BH4 synthesis) under doxycycline control potentiated in vivo tumorigenesis, tumor cell proliferation, as well as angiogenesis. Conversely, both switching off GTP cyclohydrolase I expression as well as inhibiting its enzymatic activity significantly decreased eNOS expression and tumor vascularization. This study demonstrates an important role for BH4 synthesis in angiogenesis by the activation of eNOS for NO production, which is maintained by a PI3K/Akt-positive feedback loop through effects on wild-type Ras in endothelial cells. Our findings suggest that BH4 synthesis may be a rational target for antiangiogenesis therapy for tumors.

Phase III Randomized Trial Assessing Rofecoxib in the Adjuvant Setting of Colorectal Cancer: Final Results of the VICTOR Trial

Purpose

Laboratory and case-control studies suggest a pivotal role for the cyclooxygenase-2 (COX-2) pathway in colorectal carcinogenesis. The purpose of this study was to test whether the COX-2 inhibitor rofecoxib could reduce recurrence and improve survival when administered in the adjuvant setting of colorectal cancer (CRC).

Patients and Methods

Patients who had undergone potentially curative surgery and completion of adjuvant therapy for stage II and III CRC were randomly assigned to receive rofecoxib (20 mg daily) or placebo. The primary end point was overall survival (OS). Where formalin-fixed paraffin-embedded tumor tissue samples were available, COX-2 expression was evaluated by immunohistochemistry and correlated with clinical outcome.

Results

Two thousand four hundred thirty-four patients were entered onto the study. The trial was terminated early because of the worldwide withdrawal of rofecoxib. At this point, 1,167 patients had received rofecoxib and 1,160 patients had received placebo for median treatment durations of 7.4 and 8.2 months, respectively. For the rofecoxib and placebo arms, median follow-up times were 4.84 and 4.85 years, with 241 and 246 deaths and 297 and 329 recurrences, respectively. No difference was demonstrated in OS (hazard ratio [HR] = 0.97; 95% CI, 0.81 to 1.16; P = .75) or recurrence (HR = 0.89; 95% CI, 0.76 to 1.04; P = .15) comparing the two groups. Tumor COX-2 expression by immunohistochemistry was assessed for 871 patients, but neither prognostic nor predictive effects were observed.

Conclusion

In this study of abbreviated therapy in the adjuvant setting of CRC, rofecoxib did not improve OS or protect from recurrence in unselected patients. In addition, COX-2 expression did not correlate with prognosis overall or predict effectiveness of COX-2 inhibitors.

Regional hepatic chemotherapies in the treatment of colorectal cancer metastases to the liver

The liver is the most common site of metastatic spread of colorectal cancer (CRC). Liver may be the only site of spread in as many as 30% to 40% of patients with advanced disease and can be treated with regional therapies directed toward their liver tumors. Surgery is currently the only potentially curative treatment, with a 5-year survival rate as high as 30% to 40% in selected patients. However, fewer than 25% of cases are candidates for curative resection. A number of other locoregional therapies, such as radiofrequency or microwave ablation, cryotherapy, and chemotherapy, may be offered to patients with unresectable but isolated liver metastases. However, for most patients with metastatic spread beyond the liver, systemic chemotherapy rather than regional therapy is a more appropriate option. We review the status of various regional hepatic chemotherapies in the treatment of colorectal metastases to the liver in the light of the available, published prospective, randomized trials; this discipline has not yet been properly applied to the burgeoning use of locally ablative techniques. The regional strategies reviewed include portal venous infusion (PVI) of 5-fluorouracil (5-FU), intra-arterial chemotherapy (hepatic arterial infusion [HAI]), chemoembolization, and selective internal radiation therapy (SIRT).

Abstract 811: Stroma production within the primary tumor correlates with poor survival for stage I-II colon cancer patients

Background Recent models on metastatic invasion focus on the tumor-“host” interface, in particular the role of the stromal tissue. The stromal compartments are thought to play a major role in the process of wound healing, but there is also strong emphasis that CAF's (cancer-associated fibroblasts) are important promotors for tumor growth and progression. Assuming these models are correct we hypothesized that changes in the proportion of stroma in the primary tumor could reflect progression. We therefore investigated if the amount of intra-tumor stroma could be used as a candidate marker to identify which patients should be selected for adjuvant therapy and furthermore if treatment with a COX-2 inhibitor might improve patient outcome in those patients with high percentage of stroma (with or without chemotherapy)

Methods We have investigated the proportion of intra-tumor stroma on heamatoxylin-eosin (H&E) stained histological sections and distinguished between patients with a high amount of stroma (stroma-high) and patients with lower levels of stroma (stroma-low).

We have analyzed 135 stage I-II colon cancer patients for the proportion of tumor related stroma and for TGFβ-R2, SMAD4 and β-catenin, markers involved in pathways related to stromal production and epithelial-to-mesenchymal transition (EMT).

A series of 596 patients treated either with placebo or COX-2 inhibitor was also analyzed for proportion of stroma (VICTOR-trial).

Results

Of 135 analyzed patients 35 (25.7%) patients were stroma-high and 101 (74.3%) stroma-low. Significant differences in survival were observed between the two groups, with stroma-high patients showing poor survival (OS p&lt;0.0001, HZ 2.59; DFS p=0.0002, HZ 2.31).

A high-risk group (n=14) was identified with stroma-high and SMAD4 loss (OS p=0.008, HZ 7.98, CI 4.12-15.44, DFS p=0.005, HZ 6.57, CI 3.43-12.56); 12 of 14 (85.7%) patients died within 3 years. In a logistic-regression analysis a high proportion of stroma and SMAD4 loss were strongly related (HZ 5.42, CI 2.13-13.82, p&lt;0.001).

Results of the COX-2 inhibitor study are currently under evaluation but will be presented at the conference.

Conclusions: Conventional haematoxylin-eosin stained tumor slides contain more prognostic information than previously fathomed. This can be utilized by assessing the tumor-stroma ratio. The combination of analyzing the tumor-stroma ratio and staining for SMAD4 results in an independent parameter for confident prediction of clinical outcome. The inclusion of this parameter into standard pathological reports should be considered, in addition to the TNM classification.

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 811.

Malignant peritoneal mesothelioma. Is there a new treatment?

The authors report a novel, alternative approach to treat malignant peritoneal mesothelioma (MPeM) targeting, vascular endothelial growth factor (VEGF) using anti-VEGF (bevacizumab) chemotherapy combination.

Open access chemical and clinical probes to support drug discovery

Drug discovery resources in academia and industry are not used efficiently, to the detriment of industry and society. Duplication could be reduced, and productivity could be increased, by performing basic biology and clinical proofs of concept within open access industry-academia partnerships. Chemical biologists could play a central role in this effort.

Phase II studies of polymer-doxorubicin (PK1, FCE28068) in the treatment of breast, lung and colorectal cancer

Phase I studies of [N-(2-hydroxypropyl)methacrylamide] (HPMA) copolymer-doxorubicin previously showed signs of activity coupled with 5-fold decreased anthracycline toxicity in chemotherapy-refractory patients. Here we report phase II studies using a similar material (FCE28068) in patients with breast (n=17), non-small cell lung (NSCLC, n=29) and colorectal (n=16) cancer. Up to 8 courses of PK1 (280 mg/m(2) doxorubicin-equivalent) were given i.v., together with 123I-labelled imaging analogue. Toxicities were tolerable, with grade 3 neutropenia more prominent in patients with breast cancer (4/17, 23.5% compared with 5/62, 8.1% overall). Of 14 evaluable patients with breast cancer 3 had partial responses (PR), all anthracycline-naïve patients. In 26 evaluable patients with NSCLC, 3 chemotherapy-naïve patients had PR. In contrast, none of the 16 evaluable patients with colorectal cancer responded. Imaging of 16 patients (5 with breast cancer, 6 NSCLC, 5 colorectal cancer) showed obvious tumour accumulation in 2 metastatic breast cancers, although unfortunately no images were obtained from patients who responded. These results show 6/62 PR with limited side effects, supporting the concept that polymer-bound therapeutics can have modified and improved anticancer activities and suggesting the approach should be explored further for breast cancer and NSCLC.

Warfarin thromboprophylaxis in cancer patients with central venous catheters (WARP): an open-label randomised trial

BACKGROUND

The role and dose of anticoagulants in thromboprophylaxis for patients with cancer receiving chemotherapy through central venous catheters (CVCs) is controversial. We therefore assessed whether warfarin reduces catheter-related thrombosis compared with no warfarin and whether the dose of warfarin determines the thromboprophylactic effect.

METHODS

In 68 clinical centres in the UK, we randomly assigned 1590 patients aged at least 16 years with cancer who were receiving chemotherapy through CVCs to no warfarin, fixed-dose warfarin 1 mg per day, or dose-adjusted warfarin per day to maintain an international normalised ratio between 1.5 and 2.0. Clinicians who were certain of the benefit of warfarin randomly assigned patients to fixed-dose or dose-adjusted warfarin groups. The primary outcome was the rate of radiologically proven, symptomatic catheter-related thrombosis. Analysis was by intention to treat. This trial is registered as an International Standard Randomised Controlled Trial, number ISRCTN 50312145.

FINDINGS

Compared with no warfarin (n=404), warfarin (n=408; 324 [79%] on fixed-dose and 84 [21%] on dose-adjusted) did not reduce the rate of catheter-related thromboses (24 [6%] vs 24 [6%]; relative risk 0.99, 95% CI 0.57-1.72, p=0.98). However, compared with fixed-dose warfarin (n=471), dose-adjusted warfarin (n=473) was superior in the prevention of catheter-related thromboses (13 [3%] vs 34 [7%]; 0.38, 0.20-0.71, p=0.002). Major bleeding events were rare; an excess was noted with warfarin compared with no warfarin (7 vs 1, p=0.07) and with dose-adjusted warfarin compared with fixed-dose warfarin (16 vs 7, p=0.09). A combined endpoint of thromboses and major bleeding showed no difference between comparisons. We did not note a survival benefit in either comparison.

INTERPRETATION

The findings show that prophylactic warfarin compared with no warfarin is not associated with a reduction in symptomatic catheter-related or other thromboses in patients with cancer and therefore we should consider newer treatments.

FUNDING

Medical Research Council and Cancer Research UK.

Evolution of nonsurgical therapy for colorectal cancer

The management of colorectal cancer (CRC) has changed considerably in the past 15 years with the introduction of multiple novel active therapeutic agents. Chemotherapy regimens combining a fluoropyrimidine with either oxaliplatin or irinotecan are standard first-line and second-line therapy for advanced and metastatic disease. The first-line use of these combinations produces tumor response rates of approximately 50% and a median overall survival of approximately 20 months. Addition of bevacizumab to first-line treatment and addition of cetuximab to salvage therapy for patients who fail to respond to irinotecan have contributed to further increases in tumor response rates and enhanced progression-free survival. Such approaches have produced only marginal overall survival benefits, however, and entail considerable cost. Adjuvant chemotherapy, delivered after surgical resection of the primary tumor, increases cure rates by approximately 10% for stage III disease and approximately 3-4% for stage II disease. Encouraging reductions in local relapse rates have been observed in patients with early rectal cancer who have undergone chemoradiotherapy, and increasingly complex regimens are currently being explored in phase II clinical trials in an attempt to increase both the operability and long-term local control of CRC. The greater the therapeutic choice, the greater the cost (both financial and in terms of toxicity), thus the keener the clinical community becomes to develop biomarkers to select patient populations who will be most likely to benefit from a specific agent.

A phase II study of adoptive immunotherapy using dendritic cells pulsed with tumor lysate in patients with hepatocellular carcinoma

This is a phase II clinical trial investigating the safety and efficacy of intravenous vaccination with mature autologous dendritic cells (DCs) pulsed ex vivo with a liver tumor cell line lysate (HepG2) in patients with advanced hepatocellular carcinoma (HCC). HCC is an attractive target for immunotherapy as evidenced by an active recruitment of tumor-infiltrating lymphocytes that are capable of lysing autologous tumor cells in ex vivo studies. DCs are the most potent antigen-presenting cells, with the capacity to take up, process, and present tumor antigens to T cells and stimulate an immune response, thus providing a rational platform for vaccine development. Thirty-five patients with advanced HCC and not suitable for radical or loco-regional therapies received a maximum of six DC vaccinations each at 3-week intervals. In total, 134 DC infusions were administered with no significant toxicity and no evidence of autoimmunity. Twenty-five patients who received at least three vaccine infusions were assessed clinically for response. The radiologically determined disease control rate (combined partial response and stable disease >or=3 months) was 28%. In 17 patients the baseline serum alpha-fetoprotein (AFP) was >or= 1,000 ng/mL; in four of these patients, it fell to <30% of baseline following vaccination. In one patient there was a radiological partial response associated with a fall in AFP to <10% of baseline. Immune responses were assessed using an ELIspot assay of interferon-gamma (IFN-gamma) release. In several cases there was induction of T cell responses to the vaccine and/or AFP following vaccination.

CONCLUSION

Autologous DC vaccination in patients with HCC is safe and well tolerated with evidence of antitumor efficacy assessed radiologically and serologically, with generation of antigen-specific immune responses in some cases.