Final results of a phase III clinical trial on adjuvant intraportal infusion with heparin and 5-fluorouracil (5-FU) in resectable colon cancer (EORTC GITCCG 1983-1987). European Organization for Research and Treatment of Cancer. Gastrointestinal Tract Cancer Cooperative Group

Efficacy of various adjuvant chemotherapy methods in preventing liver metastasis from potentially curative colorectal cancer: A systematic review network meta-analysis of randomized clinical trials

PURPOSE

Various chemotherapy administration methods have been used to prevent liver metastasis (LM) in patients with colorectal cancer (CRC). This network meta-analysis evaluated the efficacy of these different methods in preventing LM in CRC patients who underwent curative surgery.

METHOD

A systematic search of randomized controlled trials reporting the efficacy of various adjuvant chemotherapy methods in patients with colorectal cancer who underwent curative surgery was conducted. The primary outcome was the LM rate.

RESULTS

This network meta-analysis included 19 studies reporting on 12,588 participants, comparing portal vein infusion chemotherapy (PVIC) versus hepatic arterial infusion chemotherapy (HAIC) versus systematic chemotherapy (SC) versus surgery alone. The HAIC group had the lowest LM rate when compared to the other three groups (odds ratio [OR] of PVIC vs. HAIC: 1.86; OR of SC vs. HAIC: 1.98; and HAIC vs. surgery alone: 0.43). The LM rate did not differ significantly between PVIC, SC, and surgery alone. The recurrence rates were lower for PVIC and HAIC than for surgery alone (the ORs for PVIC and HAIC were 0.73 [95% CI: 0.58-0.92] and 0.45 [95% CI: 0.26-0.77]). The mortality rates of patients undergoing PVIC and HAIC were lower than that of patients undergoing surgery alone (the ORs for PVIC and HAIC were 0.77 [95% CI: 0.64-0.93] and 0.49 [95% CI: 0.24-0.98]). Anastomotic leakage, cardiopulmonary leakage, diarrhea, nausea and vomiting, oral ulceration, wound infection, or ileus did not differ significantly between the four groups. PVIC showed the highest hepatic toxicity rate compared to those for SC, HAIC, and surgery alone.

CONCLUSION

HAIC might be a satisfactory method for preventing LM in patients with CRC undergoing curative surgery.

Recurrence Risk after Radical Colorectal Cancer Surgery-Less Than before, But How High Is It?

Simple Summary

Evidence indicates that recurrence risk after colon cancer today is less than it was when trials performed decades ago showed that adjuvant chemotherapy reduces the risk and prolong disease-free and overall survival. After rectal cancer surgery, local recurrence rates have decreased but it is unclear if systemic recurrences have. After a systematic review of available literature reporting recurrence risks after curative colorectal cancer surgery we report that the risks are lower today than they were in the past and that this risk reduction is not solely ascribed to the use of adjuvant therapy. Adjuvant therapy always means overtreatment of many patients, already cured by the surgery. Fewer recurrences mean that progress in the care of these patients has happened but also that the present guidelines giving recommendations based upon old data must be adjusted. The relative gains from adding chemotherapy are not altered, but the absolute number of patients gaining is less.

Abstract

Adjuvant chemotherapy aims at eradicating tumour cells sometimes present after radical surgery for a colorectal cancer (CRC) and thereby diminish the recurrence rate and prolong time to recurrence (TTR). Remaining tumour cells will lead to recurrent disease that is usually fatal. Adjuvant therapy is administered based upon the estimated recurrence risk, which in turn defines the need for this treatment. This systematic overview aims at describing whether the need has decreased since trials showing that adjuvant chemotherapy provides benefits in colon cancer were performed decades ago. Thanks to other improvements than the administration of adjuvant chemotherapy, such as better staging, improved surgery, the use of radiotherapy and more careful pathology, recurrence risks have decreased. Methodological difficulties including intertrial comparisons decades apart and the present selective use of adjuvant therapy prevent an accurate estimate of the magnitude of the decreased need. Furthermore, most trials do not report recurrence rates or TTR, only disease-free and overall survival (DFS/OS). Fewer colon cancer patients, particularly in stage II but also in stage III, today display a sufficient need for adjuvant treatment considering the burden of treatment, especially when oxaliplatin is added. In rectal cancer, neo-adjuvant treatment will be increasingly used, diminishing the need for adjuvant treatment.

Pleiotropic effects of heparins: does anticoagulant treatment increase survival in cancer patients?

The association between venous thromboembolism (VTE) and cancer has been recognized for more than 100 years. Numerous studies have been performed to investigate strategies to decrease VTE incidence and to establish whether treating VTE impacts cancer progression and overall survival. Accordingly, it is important to understand the role of the hemostatic system in tumorigenesis and progression, as there is abundant evidence associating it with cell survival and proliferation, tumor angiogenesis, invasion, and dissemination, and metastasis formation. In attempts to further the scientific evidence, several studies examine survival benefits in cancer patients treated with anticoagulant therapy, specifically treatment with vitamin K antagonists, unfractionated heparin, and low-molecular-weight heparin. Several studies and meta-analyses have been conducted with a special focus on brain tumors. However, no definitive conclusions have been obtained, and more well-designed clinical trials are needed.

Heparin blocks transfer of extracellular vesicles between donor and recipient cells

Extracellular vesicles (EVs) have been implicated in tumorigenesis. Biomolecules which can block EV binding and uptake into recipient cells may be of therapeutic value as well as enhance understanding of EV biology. Here, we show that heparin interacts with uptake of tumor-derived as well as non-tumor-derived EVs into recipient cells. Incubation of glioma cell-derived EVs with heparin resulted in micron-sized structures observed by transmission electron microscopy, with EVs clearly visible within these structures. Inclusion of heparin greatly diminished transfer of labeled EVs from donor to recipient tumor cells. We also show a direct interaction between heparin and EVs using confocal microscopy. We found that the block in EV uptake was at the level of cell binding and not internalization. Finally, incubation of glioma-derived EVs containing EGFRvIII mRNA with heparin reduced transfer of this message to recipient cells. The effect of heparin on EVs uptake may provide a unique tool to study EV function. It may also foster research of heparin or its derivatives as a therapeutic for disease in which EVs play a role.

Comparison of different adjuvant therapies for 9 resectable cancer types

PURPOSE

The objective of this study was to compare the clinical benefit across adjuvant therapies for cancer treatment, including adjuvant imatinib, and to quantify the results using the number-needed-to-treat (NNT) approach.

METHOD

We reviewed studies meeting the following criteria: 1) US and European randomized clinical trial populations consisting of patients with cancer who underwent surgical resection of the primary tumor and were considered cancer free; 2) comparators were either placebo or no treatment; and 3) recurrence-free survival (RFS) and overall survival (OS) rates were reported and showed benefit with the experimental treatment. The NNT was calculated as the inverse of the difference in event rate between the study groups in each trial.

RESULTS

We identified 26 adjuvant treatment trials in 9 cancer types. With longer follow-up (3 years vs 1 year), 62.5% of treatments compared with placebo showed a decreased RFS NNT, including imatinib (7 vs 4). The largest relative decrease in RFS NNT over time was 91% (with trastuzumab or cyclophosphamide therapy). Approximately 25% of the treatments resulted in an increase in RFS NNT over time. The RFS NNT for imatinib was lower than that for all other treatments at 3 years of follow-up and lower than that for all but 2 treatments at 1 year. At both year 1 and year 3, the NNT for OS ranged from 6 to 100. Imatinib had an OS NNT of 31 at 3 years.

CONCLUSION

With longer follow-up duration, most adjuvant cancer treatments showed a decreased NNT. Imatinib had one of the lowest NNTs among the adjuvant treatments at 1 and 3 years of follow-up using the RFS data.

Impact of venous thromboembolism and anticoagulation on cancer and cancer survival

Changes in the hemostatic system and chronic hemostatic activation are frequently observed in patients with cancer, even in the absence of venous thromboembolism (VTE). VTE is a leading cause of death among patients with cancer and contributes to long-term mortality in patients with early as well as advanced-stage cancer. Mounting evidence suggests that components of the clotting cascade and associated vascular factors play an integral part in tumor progression, invasion, angiogenesis, and metastasis formation. Furthermore, there are intriguing in vitro and animal findings that anticoagulants, in particular the low molecular weight heparins (LMWHs), exert an antineoplastic effect through multiple mechanisms, including interference with tumor cell adhesion, invasion, metastasis formation, angiogenesis, and the immune system. Several relatively small randomized controlled clinical trials of anticoagulation as cancer therapy in patients without a VTE diagnosis have been completed. These comprise studies with LMWH, unfractionated heparin, and vitamin K antagonists, with overall encouraging but nonconclusive results and some limitations. Meta-analyses performed for the American Society of Clinical Oncology VTE Guidelines Committee and the Cochrane Collaboration suggest overall favorable effects of anticoagulation on survival of patients with cancer, mainly with LMWH. However, definitive clinical trials have been elusive and questions remain regarding the importance of tumor type and stage on treatment efficacy, the impact of fatal thromboembolic events, optimal anticoagulation therapy, and safety with differing chemotherapy regimens. Although the LMWHs and related agents hold promise for improving outcomes in patients with cancer, additional studies of their efficacy and safety in this setting are needed.

Adjuvant therapy for completely resected stage II colon cancer

BACKGROUND

Colon cancer is potentially curable by surgery. Although adjuvant chemotherapy benefits patients with stage III disease, there is uncertainty of such benefit in stage II colon cancer. A systematic review of the literature was performed to better define the potential benefits of adjuvant therapy for patients with stage II colon cancer.

OBJECTIVES

To determine the effects of adjuvant therapy on overall survival and disease-free survival in patients with stage II colon cancer.

SEARCH STRATEGY

Ovid MEDLINE (1986-2007), EMBASE (1980-2007), and EBM Reviews - Cochrane Central Register of Controlled Trials ( to 2007) were searched using the medical headings "colonic neoplasms", "colorectal neoplasms", "adjuvant chemotherapy", "adjuvant radiotherapy" and "immunotherapy", and the text words "colon cancer" and "colonic neoplasms". In addition, proceedings from the annual meetings of the American Society of Clinical Oncology and the European Society of Medical Oncology (1996 to 2004) as well as personal files were searched for additional information.

SELECTION CRITERIA

Randomized trials or meta-analyses containing data on stage II colon cancer patients undergoing adjuvant therapy versus surgery alone.

DATA COLLECTION AND ANALYSIS

:Three reviewers summarized the results of selected studies. The main outcomes of interest were overall and disease-free survival, however, data on toxicity and treatment delivery were also recorded.

MAIN RESULTS

With regards to the effect of adjuvant therapy on stage II colon cancer, the pooled relative risk ratio for overall survival was 0.96 (95% confidence interval 0.88, 1.05). With regards to disease-free survival, the pooled relative risk ratio was 0.83 (95% confidence interval 0.75, 0.92).

AUTHORS' CONCLUSIONS

Although there was no improvement in overall survival in the pooled analysis, we did find that disease-free survival in patients with stage II colon cancer was significantly better with the use of adjuvant therapy. It seems reasonable to discuss the benefits of adjuvant systemic chemotherapy with those stage II patients who have high risk features, including obstruction, perforation, inadequate lymph node sampling or T4 disease. The co-morbidities and likelihood of tolerating adjuvant systemic chemotherapy should be considered as well. There exists a need to further define which high-risk features in stage II colon cancer patients should be used to select patients for adjuvant therapy. Also, researchers must continue to search for other therapies which might be more effective, shorter in duration and less toxic than those available today.

American Society of Clinical Oncology guideline: recommendations for venous thromboembolism prophylaxis and treatment in patients with cancer

PURPOSE

To develop guideline recommendations for the use of anticoagulation in the prevention and treatment of venous thromboembolism (VTE) in patients with cancer.

METHODS

A comprehensive systematic review of the medical literature on the prevention and treatment of VTE in cancer patients was conducted and reviewed by a panel of content and methodology experts. Following discussion of the results, the panel drafted recommendations for the use of anticoagulation in patients with malignant disease.

RESULTS

The results of randomized controlled trials of primary and secondary VTE medical prophylaxis, surgical prophylaxis, VTE treatment, and the impact of anticoagulation on survival of patients with cancer were reviewed. Recommendations were developed on the prevention of VTE in hospitalized, ambulatory, and surgical cancer patients as well as patients with established VTE, and for use of anticoagulants in cancer patients without VTE to improve survival.

CONCLUSION

Recommendations of the American Society of Clinical Oncology VTE Guideline Panel include (1) all hospitalized cancer patients should be considered for VTE prophylaxis with anticoagulants in the absence of bleeding or other contraindications; (2) routine prophylaxis of ambulatory cancer patients with anticoagulation is not recommended, with the exception of patients receiving thalidomide or lenalidomide; (3) patients undergoing major surgery for malignant disease should be considered for pharmacologic thromboprophylaxis; (4) low molecular weight heparin represents the preferred agent for both the initial and continuing treatment of cancer patients with established VTE; and (5) the impact of anticoagulants on cancer patient survival requires additional study and cannot be recommended at present.

A meta-analysis and systematic review of the efficacy and safety of anticoagulants as cancer treatment: impact on survival and bleeding complications

BACKGROUND

Preclinical evidence suggests that anticoagulants, in particular the low-molecular-weight heparins (LMWH), exert an antitumor effect, whereas clinical trials have reported conflicting results. The authors conducted a comprehensive, systematic review and meta-analysis of the evidence from randomized controlled trials (RCTs), to evaluate the impact of anticoagulants on survival and safety in cancer patients without venous thromboembolism.

METHODS

A comprehensive systematic literature review of RCTs was performed without language restrictions through May 2006 with subsequent updates to the end of 2006, including an exhaustive search of electronic databases, major conference proceedings, article references, and content experts. Two reviewers extracted data independently. Primary study outcomes were 1-year overall mortality and all bleeding complications. Major and fatal bleeding complications were secondary outcomes.

RESULTS

Across all 11 studies that were identified, anticoagulation significantly decreased 1-year overall mortality with a relative risk (RR) of 0.905 (95% confidence interval [95% CI], 0.847-0.967; P = .003). The RR for mortality was 0.877 (95% CI, 0.789-0.975; P = .015) for LMWH, compared with an RR of 0.942 (95% CI, 0.854-1.040; P = .239) for warfarin, resulting in an absolute risk difference (ARD) of 8% for LMWH and an ARD of 3% for warfarin. Improved survival with anticoagulation may be dependent on tumor type. Major bleeding episodes occurred less frequently in patients who received LMWH (ARD, 1%) compared with patients who received warfarin (ARD, 11.5%; P < .0001). Overall, fatal bleeding occurred rarely (ARD, 0.32%; P = .542).

CONCLUSIONS

Anticoagulants, particularly LMWH, significantly improved overall survival in cancer patients without venous thrombosis while increasing the risk for bleeding complications. However, given the limitations of available data, the use of anticoagulants as antineoplastic therapy cannot be recommended until additional RCTs confirm these results.

Endpoints in Adjuvant Treatment Trials: A Systematic Review of the Literature in Colon Cancer and Proposed Definitions for Future Trials

Disease-free survival is increasingly being used as the primary endpoint of most trials testing adjuvant treatments in cancer. Other frequently used endpoints include overall survival, recurrence-free survival, and time to recurrence. These endpoints are often defined differently in different trials in the same type of cancer, leading to a lack of comparability among trials. In this Commentary, we used adjuvant studies in colon cancer as a model to address this issue. In a systematic review of the literature, we identified 52 studies of adjuvant treatment in colon cancer published in 1997-2006 that used eight other endpoints in addition to overall survival. Both the definition of these endpoints and the starting point for measuring time to the events that constituted these endpoints varied widely. A panel of experts on clinical research on colorectal cancer then reached consensus on the definition of each endpoint. Disease-free survival--defined as the time from randomization to any event, irrespective of cause--was considered to be the most informative endpoint for assessing the effect of treatment and therefore the most relevant to clinical practice. The proposed guidelines may add to the quality and cross-comparability of future studies of adjuvant treatments for cancer.

Selectin Blocking Activity of a Fucosylated Chondroitin Sulfate Glycosaminoglycan from Sea Cucumber

Heparin is an excellent inhibitor of P- and L-selectin binding to the carbohydrate determinant, sialyl Lewis(x). As a consequence of its anti-selectin activity, heparin attenuates metastasis and inflammation. Here we show that fucosylated chondroitin sulfate (FucCS), a polysaccharide isolated from sea cucumber composed of a chondroitin sulfate backbone substituted at the 3-position of the beta-D-glucuronic acid residues with 2,4-disulfated alpha-L-fucopyranosyl branches, is a potent inhibitor of P- and L-selectin binding to immobilized sialyl Lewis(x) and LS180 carcinoma cell attachment to immobilized P- and L-selectins. Inhibition occurs in a concentration-dependent manner. Furthermore, FucCS was 4-8-fold more potent than heparin in the inhibition of the P- and L-selectin-sialyl Lewis(x) interactions. No inhibition of E-selectin was observed. FucCS also inhibited lung colonization by adenocarcinoma MC-38 cells in an experimental metastasis model in mice, as well as neutrophil recruitment in two models of inflammation (thioglycollate-induced peritonitis and lipopolysaccharide-induced lung inflammation). Inhibition occurred at a dose that produces no significant change in plasma activated partial thromboplastin time. Removal of the sulfated fucose branches on the FucCS abolished the inhibitory effect in vitro and in vivo. Overall, the results suggest that invertebrate FucCS may be a potential alternative to heparin for blocking metastasis and inflammatory reactions without the undesirable side effects of anticoagulant heparin.

Can biliary carcinoembryonic antigen identify colorectal cancer patients with occult hepatic metastases?

BACKGROUND

Twenty-five percent of radically treated colorectal cancer patients already have occult hepatic metastases (OHM) that will later be observed during postoperative follow-up. Instrumental examinations, i.e., intraoperative ultrasound or Doppler perfusion index, have not improved diagnosis. As carcinoembyonic antigen (CEA) levels are useful to reveal hepatic metastases from colorectal cancer, determination of CEA in the bile rather than the blood may allow preclinical diagnosis of OHM thanks to the reduced volume of bile.

METHODS

One hundred radically treated colorectal cancer patients were enrolled in the study. Bile was withdrawn from the gallbladder intraoperatively and biliary CEA levels determined using an immuno-enzymatic method (normal value 0-5 ng/ml). Eighty-nine fully evaluable patients were followed up for three years postoperatively to monitor hepatic metastases. Preoperative blood CEA, lymph node metastases and biliary CEA were compared in order to assess which procedure was more efficient in identifying patients who would develop hepatic metastases.

RESULTS

Eleven of the 89 evaluable patients developed hepatic metastases: 9/11 presented elevated biliary CEA levels (mean: 12.73; range: 5.1-26.2); 8/11 had high preoperative blood CEA values; and 9/11 were at anatomopathological stage N+. In the 78 patients who did not develop hepatic metastases, biliary CEA was within normal limits in 73/78, preoperative blood CEA was normal in 60/78, and 58/78 patients were at anatomopathological stage N-. Hence, the sensitivity of biliary CEA was 81.8%, specificity was 93.6%, and diagnostic accuracy was 92.1%.

CONCLUSIONS

Determination of biliary CEA seems to be more efficient in identifying patients presenting OHM who require frequent clinical examinations or adjuvant cancer treatment.

Glycans in cancer and inflammation--potential for therapeutics and diagnostics

Changes in glycosylation are often a hallmark of disease states. For example, cancer cells frequently display glycans at different levels or with fundamentally different structures than those observed on normal cells. This phenomenon was first described in the early 1970s, but the molecular details underlying such transformations were poorly understood. In the past decade advances in genomics, proteomics and mass spectrometry have enabled the association of specific glycan structures with disease states. In some cases, the functional significance of disease-associated changes in glycosylation has been revealed. This review highlights changes in glycosylation associated with cancer and chronic inflammation and new therapeutic and diagnostic strategies that are based on the underlying glycobiology.

Adjuvant therapy for stage II colon cancer: a systematic review from the Cancer Care Ontario Program in evidence-based care's gastrointestinal cancer disease site group

PURPOSE

To develop a systematic review that would address the following question: Should patients with stage II colon cancer receive adjuvant therapy?

METHODS

A systematic review was undertaken to locate randomized controlled trials comparing adjuvant therapy to observation.

RESULTS

Thirty-seven trials and 11 meta-analyses were included. The evidence for stage II colon cancer comes primarily from a trial of fluorouracil plus levamisole and a meta-analysis of 1,016 patients comparing fluorouracil plus folinic acid versus observation. Neither detected an improvement in disease-free or overall survival for adjuvant therapy. A recent pooled analysis of data from seven trials observed a benefit for adjuvant therapy in a multivariate analysis for both disease-free and overall survival. The disease-free survival benefits appeared to extend to stage II patients; however, no P values were provided. A meta-analysis of chemotherapy by portal vein infusion has also shown a benefit in disease-free and overall survival for stage II patients. A meta-analysis was conducted using data on stage II patients where data were available (n = 4,187). The mortality risk ratio was 0.87 (95% CI, 0.75 to 1.01; P =.07).

CONCLUSION

There is preliminary evidence indicating that adjuvant therapy is associated with a disease-free survival benefit for patients with stage II colon cancer. These benefits are small and not necessarily associated with improved overall survival. Patients should be made aware of these results and encouraged to participate in active clinical trials. Additional investigation of newer therapies and more mature data from the presently available trials should be pursued.

The EORTC Gastrointestinal Tract Cancer Group: 40 years of research contributing to improved GI cancer management

The Gastrointestinal (GI) Tract Cancer Group's aims are to develop protocols concerning the different aspects of gastrointestinal tract malignancies, diagnosis, biology and mainly treatment. Prior to approval, new project proposals are discussed within different committees of the group and in the presence of specialists concerned, according to the type of trial. There are three main committees in the GI Group, chemotherapy, surgery and research. All projects of GI tract cancer are discussed first in the relevant committee before being discussed in the multidisciplinary plenary scientific session of the Group meeting. Multidisciplinarity has always been one of the major principles of the Group. This is well illustrated by the fact that the Chairman of the Group has been alternately a medical oncologist and a surgeon and is presently a surgeon. Radiation therapists also participate in the activity of the group. Like other EORTC groups, the GI Group has developed high standards of quality. Officers and members work in close co-operation with the staff of the Data Center in Brussels and in particular medical advisors, statisticians and data managers. Members from 32 different countries participate in the activities of the Group, mostly from European countries, but also from Russia, Egypt, Hong Kong, Israel, Peru, Russia, South Africa and many others through intergroup activities such as Australia, Canada and the USA.

Review article: non-systemic chemotherapy in the treatment of colorectal cancer-portal vein, hepatic arterial and intraperitoneal approaches

Loco-regional chemotherapy, an alternative to systemic chemotherapy in the management of colorectal cancer, has been evaluated in both adjuvant and palliative settings. The rationale for loco-regional delivery is to achieve higher dose concentrations of drugs at the tumour site or at the most common sites of tumour recurrence, while limiting systemic exposure and associated toxicity. Adjuvant intraportal chemotherapy and palliative hepa-tic arterial chemotherapy have been most extensively investigated. Intraperitoneal chemotherapy has also been studied as an adjuvant treatment after complete resection of colorectal cancer or cytoreductive surgery in patients with established peritoneal carcinomatosis. The results obtained have been disappointing, and none of these procedures can be considered as a standard therapeutic option today. However, methodological difficulties were encountered in most published studies, and the investigated schedules and doses may not have been optimal. New combinations of cytotoxic drugs and new indications are currently under consideration. Promising results have recently been published for adjuvant intraperitoneal chemotherapy and hepatic arterial chemotherapy following surgical resection of hepatic metastases, but additional well-designed multicentre phase III trials are needed to determine the true benefits of these treatment modalities and to address the issues of cost and quality of life.

P-selectin, carcinoma metastasis and heparin: novel mechanistic connections with therapeutic implications

Metastasis is a multistep cascade initiated when malignant cells penetrate the tissue surrounding the primary tumor and enter the bloodstream. Classic studies indicated that blood platelets form complexes around tumor cells in the circulation and facilitate metastases. In other work, the anticoagulant drug heparin diminished metastasis in murine models, as well is in preliminary human studies. However, attempts to follow up the latter observation using vitamin K antagonists failed, indicating that the primary mechanism of heparin action was unrelated to its anticoagulant properties. Other studies showed that the overexpression of sialylated fucosylated glycans in human carcinomas is associated with a poor prognosis. We have now brought all these observations together into one mechanistic explanation, which has therapeutic implications. Carcinoma cells expressing sialylated fucosylated mucins can interact with platelets, leukocytes and endothelium via the selectin family of cell adhesion molecules. The initial organ colonization of intravenously injected carcinoma cells is attenuated in P-selectin-deficient mice, in mice receiving tumor cells pretreated with O-sialoglycoprotease (to selectively remove mucins from cell surfaces), or in mice receiving a single dose of heparin prior to tumor cell injection. In each case, we found that formation of a platelet coating on cancer cells was impeded, allowing increased access of leukocytes to the tumor cells. Several weeks later, all animals showed a decrease in the extent of established metastasis, indicating a long-lasting effect of the short-term intervention. The absence of obvious synergism amongst the three treatments suggests that they all act via a common pathway. Thus, a major mechanism of heparin action in cancer may be inhibition of P-selectin-mediated platelet coating of tumor cells during the initial phase of the metastatic process. We therefore suggest that heparin use in cancer be re-explored, specifically during the time interval between initial visualization of a primary tumor until just after definitive surgical removal.

Heparin and cancer revisited: mechanistic connections involving platelets, P-selectin, carcinoma mucins, and tumor metastasis

Independent studies indicate that expression of sialylated fucosylated mucins by human carcinomas portends a poor prognosis because of enhanced metastatic spread of tumor cells, that carcinoma metastasis in mice is facilitated by formation of tumor cell complexes with blood platelets, and that metastasis can be attenuated by a background of P-selectin deficiency or by treatment with heparin. The effects of heparin are not primarily due to its anticoagulant action. Other explanations have been suggested but not proven. Here, we bring together all these unexplained and seemingly disparate observations, showing that heparin treatment attenuates tumor metastasis in mice by inhibiting P-selectin-mediated interactions of platelets with carcinoma cell-surface mucin ligands. Selective removal of tumor mucin P-selectin ligands, a single heparin dose, or a background of P-selectin deficiency each reduces tumor cell-platelet interactions in vitro and in vivo. Although each of these maneuvers reduced the in vivo interactions for only a few hours, all markedly reduce long-term organ colonization by tumor cells. Three-dimensional reconstructions by using volume-rendering software show that each situation interferes with formation of the platelet "cloak" around tumor cells while permitting an increased interaction of monocytes (macrophage precursors) with the malignant cells. Finally, we show that human P-selectin is even more sensitive to heparin than mouse P-selectin, giving significant inhibition at concentrations that are in the clinically acceptable range. We suggest that heparin therapy for metastasis prevention in humans be revisited, with these mechanistic paradigms in mind.

Adjuvant chemotherapy for colon cancer

Colon cancer remains the third most common cancer, and cause of cancer-related death in the United States. Greater public awareness and acceptance of screening programs have contributed significantly to increasingly earlier detection of colon cancer and decreased mortality. Advances made in the understanding of this disease, both in terms of its clinical behavior and molecular pathogenesis, have translated into major improvements in its therapy. Several large randomized trials during the last two decades have helped the oncology community forge a successful multi-modality treatment strategy against colon cancer. These studies have defined the role of adjuvant therapy for colon cancer after curative surgery. Despite all the advances, a large number of patients continue to succumb to this disease, and the search for better therapies is still necessary. In this article, we discuss the evolution and the current state of adjuvant chemotherapy in colon cancer and briefly review new developments.

Adjuvant intraportal chemotherapy for Dukes B2 and C colorectal cancer also receiving systemic treatment: results of a multicenter randomized trial. Groupe Régional d'Etude du Cancer Colo-Rectal (Belgium)

In a randomized trial, the authors evaluated the possible adjuvant activity of intraportal chemotherapy (with 5-fluorouracil 500 mg/m2/day in continuous infusion for 7 days and mitomycin C 10 mg/m2 at day 7) administered after surgery to half of the patients who underwent a full resection for Dukes B2 or C colorectal cancer. The procedure appeared manageable and safe. Two hundred and sixty patients were initially randomized, among whom 173 were finally considered as fully evaluable after having completed six courses of systemic chemotherapy. The reasons for withdrawal were basically tumoral ones and patients or doctors compliance. After a median follow-up of 4.5 years, no difference could be observed in the patients evolution assessed as relapses or deaths rate, or as relapse-free (at 5 years: 68% in the portal treatment group versus 70% in the control group) or overall survival (at 5 years: 76 versus 74%). The frequency of hepatic metastases (21 versus 18%) was also similar in both groups.

Adjuvant portal-vein infusion of fluorouracil and heparin in colorectal cancer: a randomised trial. European Organisation for Research and Treatment of Cancer Gastrointestinal Tract Cancer Cooperative Group, the Gruppo Interdisciplinare Valutazione Interventi in Oncologia, and the Japanese Foundation for Cancer Research

BACKGROUND

There is conflicting evidence on the efficacy of regional adjuvant chemotherapy, via portal-vein infusion (PVI), after resection of colorectal cancer. We undertook a randomised controlled multicentre trial to investigate the efficacy of PVI (500 mg/m2 fluorouracil plus 5000 IU heparin daily for 7 days).

METHODS

1235 of about 1500 potentially eligible patients were randomly assigned surgery plus PVI or surgery alone (control). The patients were followed up for a median of 63 months, with yearly screening for recurrent disease. The primary endpoint was survival; analyses were by intention to treat.

FINDINGS

619 patients in the control group and 616 in the PVI group met eligibility criteria. 164 (26%) control-group patients and 173 (28%) PVI-group patients died. 5-year survival did not differ significantly between the groups (73 vs 72%; 95% Cl for difference -6 to 4). The control and PVI groups were also similar in terms of disease-free survival at 5 years (67 vs 65%) and the number of patients with liver metastases (79 vs 77%).

INTERPRETATION

PVI of fluorouracil, at a dose of 500 mg/m2 for 7 days, cannot be recommended as the sole adjuvant treatment for high-risk colorectal cancer after complete surgical excision. However, these results cannot eliminate a small benefit when PVI is used at a higher dosage or in combination with mitomycin.