Prognostic implication of ABC transporters and cancer stem cell markers in patients with stage III colon cancer receiving adjuvant FOLFOX-4 chemotherapy

Cancer stem cell (CSC) and ATP-binding cassette (ABC) transporters are associated with treatment resistance and outcomes of patients with cancer. The present study investigated the prognostic implications of pre-therapeutic expression of ABC transporters and CSC markers in patients with colon cancer (CC) who received adjuvant 5-fluorouracil, leucovorin and oxaliplatin combination therapy (FOLFOX-4). The immunohistochemical expression of 3 ABC transporters, including ABC subfamily C member 2 (ABCC2), ABCC3 and ABC subfamily G member 2 (ABCG2), and 3 CSC markers, including sex determining region Y-box 2 (SOX2), leucine-rich repeat-containing G protein-coupled receptor 5 and aldehyde dehydrogenase 1, were determined in 164 CC tissues from patients with stage III CC, who underwent postoperative FOLFOX-4 chemotherapy. The association between the protein expression and patients' prognoses was statistically analyzed. ABCG2 was associated with favorable overall survival rate (OS; P=0.001), and ABCC2, ABCG2 and SOX2 were associated with increased disease-free survival rate (DFS; P=0.001, 0.002 and 0.013, respectively). In multivariate analyses, ABCG2 was an independent prognostic factor for OS [hazard ratio (HR)=2.877; P=0.046], and ABCC2 and SOX2 were independent prognostic factors for DFS (HR=2.831; P=0.014; HR=2.558, P=0.020, respectively). ABCC2, ABCG2 and SOX2 may be promising prognostic markers for patients with CC receiving FOLFOX-4 therapy.

Hospital Variability in Use of Adjuvant Chemotherapy for Patients with Stage 2 and 3 Colon Cancer

BACKGROUND

Following oncologic resection, adjuvant chemotherapy is associated with decreased recurrence and improved survival in stage 3 colon cancer. However, there is controversy regarding its use in stage 2 colon cancer with high-risk features (tumor depth T4, poorly differentiated, positive margin, and/or inadequate lymph node retrieval). Consensus guidelines recommend no adjuvant chemotherapy in the absence of these high-risk features (low-risk stage 2).

OBJECTIVE

This study aimed to examine hospital characteristics associated with poor risk-adjusted, stage-specific guideline compliance for the use of adjuvant chemotherapy in stage 3 and low-risk stage 2 colon cancer.

DESIGN

This was a retrospective study. Stepwise logistic regression was used to identify patient and hospital factors associated with administration of adjuvant chemotherapy. Hierarchical regression models were used to calculate risk- and reliability-adjusted rates of chemotherapy use and observed-to-expected ratios in each hospital's stage 2 low-risk and stage 3 patients.

SETTINGS

Data were retrieved from the National Cancer Database.

PATIENTS

Patients selected were adults treated with oncologic resection for stage 2 to 3 colon cancer between 2004 and 2010.

MAIN OUTCOME MEASURES

The primary outcome measured was receipt of adjuvant chemotherapy.

RESULTS

A total of 167,345 patients were identified at 1395 hospitals. The mean overall risk-adjusted adjuvant chemotherapy rate was 65.3% for stage 3 and 15.2% for low-risk stage 2. Analysis of low outlier hospitals for stage 3 colon cancer, where adjuvant chemotherapy was underutilized, demonstrated that 62.8% were low-volume centers and 51.4% were community centers. Of high outlier hospitals for stage 2 low-risk disease, where adjuvant chemotherapy was overutilized, 87.2% were low-volume hospitals and 67.2% were community centers.

LIMITATIONS

Selection bias and the inability to compare specific chemotherapy regimens were limitations of this study.

CONCLUSIONS

Following oncologic resection, administration of adjuvant chemotherapy for low-risk stage 2 and stage 3 disease varies substantially among hospitals in the United States. Outlier hospitals were most likely to be low-volume community centers.

Clinical update: colon, rectal, and anal cancers

OBJECTIVES

To present an updated review of the incidence, risk factors, staging, diagnosis, and treatment of colon, rectal, and anal cancers, as well as nursing care associated with managing patients diagnosed with these malignancies.

DATA SOURCES

Published research reports, epidemiologic data, published patient management guidelines, and institution-based clinical tools.

CONCLUSION

While significant advances in the management of colon, rectal, and anal cancers in the past decade have extended patient survival, there remain some unanswered questions. Further clinical and molecular research will help individualize patient care, refining current therapeutic strategies and treatment decision-making aids while minimizing symptoms of disease and treatment.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be familiar with risk factors, disease course, and current and emerging therapies to assist patients with treatment decision-making, and to anticipate and intervene in managing disease and treatment-induced problems. Early identification and management of distressing symptoms can help to avoid life-threatening effects and promote patient adherence to prescribed therapies; timely patient/family education may minimize anxiety and promote self-management.

Ca/Mg infusions for the prevention of oxaliplatin-related neurotoxicity in patients with colorectal cancer: a meta-analysis

BACKGROUND

Oxaliplatin-related neurotoxicity is the main limitation for its continuation in adjuvant and palliative chemotherapy for patients with colorectal cancer. The purpose of this meta-analysis was to determine the efficacy of calcium and magnesium (Ca/Mg) infusions in oxaliplatin-induced neurotoxicity.

METHODS

Two independent authors conducted database searches of the literature to find clinical-controlled trials analyzing Ca/Mg infusions in oxaliplatin-induced neurotoxicity. The keywords used to search were oxaliplatin, neurotoxicity, calcium, magnesium, neuropathy, and peripheral. Clinical studies that included at least one primary or secondary event were eligible for the analysis, where primary events were incidences of acute and cumulative neurotoxicity, and secondary events were the total doses and cycles of oxaliplatin, response rate (RR), overall survival (OS), and progression-free survival (PFS). Odds ratios (ORs) and weighted mean differences (MD) were analyzed using models of fixed and random effects.

RESULTS

This meta-analysis comprised four prospective randomized clinical trials and three retrospective clinical trials involving 1170 colorectal cancer patients, of which 802 received Ca/Mg infusions (Ca/Mg group) and 368 did not (control group). According to the National Cancer Institute-Common Terminology Criteria for Adverse Events, the incidence of grade 3 acute neurotoxicity in those who received Ca/Mg was significantly lower than that of the control group (OR=0.26; 95% confidence interval (CI), 0.11 to 0.62; P=0.0002). The total rate of cumulative neurotoxicity, and that of grade 3 in particular, was significantly lower in the Ca/Mg group than in the control group (OR=0.42; 95% CI 0.26-0.65; P=0.0001; OR=0.60; 95% CI 0.39-0.92; P=0.02, respectively). The differences in total doses and cycles of oxaliplatin were also significant between the Ca/Mg and control group (MD=246.73 mg/m2; 95% CI 3.01-490.45; P=0.05; MD=1.55; 95% CI 0.46-2.63; P=0.005, respectively). No significant differences were found in median PFS (MD=0.71 month; 95% CI -0.59-2.01; P=0.29), median OS (MD=0.10 month; 95% CI -0.41-0.61; P=0.70) or RRs (OR=0.82; 95% CI 0.61-1.10; P=0.18).

CONCLUSION

Ca/Mg infusions tend to decrease the incidence of oxaliplatin-induced acute and cumulative neurotoxicity and thus enhance patients' tolerance to oxaliplatin, without significantly altering the efficacy of chemotherapy.

Combination therapy in high-risk stage II or stage III colon cancer: current practice and future prospects

Colon cancer represents the second leading cause of cancer-related deaths. For patients who have undergone curative surgery, adjuvant therapy can reduce the risk of recurrence and death from relapsed or metastatic disease. Postoperative chemotherapy with a 5-fluorouracil-based regimen combined with oxaliplatin is the current standard of care for stage III patients. However, there is still controversy in stage II disease about the real impact of adjuvant monotherapy or combined therapy on survival. Better identification of a subgroup of patients with a higher risk of recurrence can select patients who might benefit from adjuvant therapy. For the elderly population, there is a well-established role for postoperative therapy, although the most appropriate regimen remains to be defined. Targeted agents for combined adjuvant therapy in stage II and III colon cancer is a promising area, but to date, there is no evidence supporting its use in this setting. Results from large prospective trials with targeted therapy have been disappointing and new drugs and strategies are needed to define the role of these types of agents in the adjuvant scenario of colon cancer.

Colon, rectal, and anal cancers

OBJECTIVES

To review the incidence, risk factors, staging, diagnosis, and treatment of colon, rectal, and anal cancers, as well as nursing care associated with managing patients diagnosed with these malignancies.

DATA SOURCES

Published research reports, epidemiologic data, published patient management guidelines, and institution-based clinical tools.

CONCLUSIONS

Significant advances in the management of colon, rectal, and anal cancers in the past decade have extended patient survival. Further clinical research will refine current therapeutic strategies and treatment decision-making aids while minimizing symptoms of disease and treatment.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to be familiar with risk factors, disease course, and current and emerging therapies to assist patients with treatment decision-making, and to anticipate and intervene in managing disease and treatment-induced problems. Early identification and management of distressing symptoms can help to avoid life-threatening effects and promote patient adherence to prescribed therapies; timely patient/family education may minimize anxiety and promote self-management.

Surrogate endpoints for overall survival in early colorectal cancer from the clinician's perspective

The administration of adjuvant chemotherapy after resection of stage III colon cancer to prolong disease-free survival (DFS) and increase overall survival (OS) has been clinical standard since the early 1990s. Recently, 3-year DFS was recognized as surrogate endpoint for OS based on a meta-analysis of trials utilizing 5-fluorouracil as only active chemotherapy component. The standard of care in adjuvant therapy, however, has moved on to modern combination regimens including oxaliplatin, and novel targeted agents such as angiogenesis inhibitors and antibodies against epidermal growth factor receptor are currently undergoing rigorous testing in phase III adjuvant trials. For the practicing clinician, the use of surrogate endpoints to appreciate the efficacy of a specific adjuvant therapy contains various challenges, in particular, in discussions with patients. It is questionable whether 3-year DFS can still be considered an appropriate predictor of OS in complex clinical scenarios with continuous change in treatment standards in the adjuvant and palliative situation. Thus, the practicing oncologist needs to be aware of the limitations in the definition of surrogate endpoints in the adjuvant setting.

New approaches to assessing and treating early-stage colon and rectal cancers: cooperative group strategies for assessing optimal approaches in early-stage disease

The U.S. Gastrointestinal Intergroup (GI Intergroup), including the National Cancer Institute of Canada, has created a portfolio of clinical trials for patients with stage II and III colon and rectal cancer, integrating therapeutic strategies from recent advanced disease trials. Fluoropyrimidine-based combination therapy for metastatic disease, with either irinotecan or oxaliplatin plus bevacizumab, has resulted in significant improvement in response and disease-free and overall survival. Cetuximab and irinotecan have produced intriguing response and progression-free survival data from randomized phase II trials. Although patients with stage II and III rectal cancer are uniformly included in individual clinical trials, the GI Intergroup conducts separate trials in patients with stage II and III colon cancer, with the exception of the National Surgical Adjuvant Breast and Bowel Project (NSABP), which continues to merge both stages in their statistical designs. The U.S. chemotherapy platform for adjuvant therapy clinical trials is based on the positive adjuvant data from NSABP C-07 [FLOX with bolus 5-fluorouracil (5-FU)] and the MOSAIC trial (FOLFOX with infusional 5-FU). Three irinotecan-based adjuvant trials (one U.S. and two European) did not reach designated statistical end points. In addition, the GI Intergroup has consistently integrated molecular biological and other laboratory projects as important components of past and current trials. NSABP has recently completed accrual of patients to C-08, which is evaluating FOLFOX with or without bevacizumab in stage II/III colon cancer. E5202, the largest U.S. stage II colon cancer trial, determines patient risk by the initial evaluation of tumor 18q loss of heterozygosity and microsatellite instability status. Low-risk patients are observed, whereas high-risk patients are randomized to FOLFOX with or without bevacizumab. N0147 evaluates FOLFOX with or without cetuximab in patients with stage III disease. Two large rectal cancer trials have begun to accrue patients. NSABP R-04 compares neoadjuvant radiation with either continuous infusion 5-FU with or without oxaliplatin versus capecitabine with or without oxaliplatin. E5204 is the adjuvant comparison of FOLFOX with or without bevacizumab and is also available to NSABP R-04 patients.

Biological therapy and other novel therapies in early-stage disease: are they appropriate?

For nearly two decades, adjuvant chemotherapy has been the standard of care in patients with early-stage colon cancer at high risk of recurrence. Until now, treatment has been based on the use of cytotoxic drugs that have well-demonstrated efficacy in advanced colorectal cancer. Most recently, targeted biological agents [i.e., antibodies against the epidermal growth factor receptor and vascular endothelial growth factor] have become essential components of the palliative medical treatment of colorectal cancer. Proof of efficacy of these agents in advanced disease has led to the initiation of several trials testing epidermal growth factor receptor and vascular endothelial growth factor antibodies in the adjuvant setting. Although definitive results of ongoing adjuvant studies will not be available for 2 to 3 years, some oncologists might already inappropriately consider the use of these targeted agents as a component of adjuvant therapy in selected patients. Whether the results obtained in advanced colorectal cancer can be readily translated into a projected efficacy in early-stage colon cancer, however, is unclear. In addition, the long-term safety of biological agents in potentially surgically cured patients has not yet been established. This review discusses the potential caveats and concerns associated with the uncritical use of targeted agents as adjuvant therapy before their safety and efficacy in this setting has been indisputably established in definitive phase III trials.

Adjuvant therapy for stage II and III colorectal cancer

Considerable progress has been made in improving disease-free survival in stage III colon cancer with the use of adjuvant chemotherapy. In recent years, it has been shown that infusional 5-fluorouracil regimens maintain the efficacy and reduce toxicity associated with bolus 5-fluorouracil, that improved tolerability can be achieved with use of the oral fluoropyrimidine capecitabine, and that improved efficacy can be achieved by combining 5-fluorouracil/leucovorin with other cytotoxic agents (eg, oxaliplatin and irinotecan). Studies are ongoing to identify optimal adjuvant regimens in stage II or III disease and to identify the potential benefits of adding bevacizumab or cetuximab to adjuvant therapy.

Chemotherapy for colorectal cancer in the metastatic and adjuvant setting: past, present and future

There have been significant advances in the use of chemotherapy in the treatment of colorectal cancer patients over the last 20 years. Initial improvements in treatment were made with increased understanding of the pharmacology of 5-fluorouracil and the discovery of modulators of its activity (e.g., leucovorin). However, in the last few years the discovery of new cytotoxic drugs with efficacy in large bowel cancer (e.g., oxaliplatin and irinotecan) and monoclonal antibodies (e.g., bevacizumab and cetuximab) have significantly improved patient outcome and prognosis. Systemic chemotherapy in the metastatic setting has been shown to prolong survival and improve quality of life. Chemotherapy now also has a clear role as an adjunct to surgery to improve survival in stage III and certain 'high-risk' stage II colorectal cancer patients. The evolution of chemotherapy use, current practice in the metastatic and adjuvant setting and possible future directions are discussed.

Cost-effectiveness analysis of oxaliplatin compared with 5-fluorouracil/leucovorin in adjuvant treatment of stage III colon cancer in the US

BACKGROUND

The MOSAIC trial demonstrated that oxaliplatin/5-fluorouracil/leucovorin (FU/LV) (FOLFOX4) as adjuvant treatment of TNM stage II and III colon cancer significantly improves disease-free survival compared with 5-FU/LV alone. For stage III patients the 4-year disease-free survival (DFS) was 69% in the FOLFOX4 arm vs 61% in the LV5FU2 arm, P = .002). The cost-effectiveness of FOLFOX4 in stage III patients was evaluated from a US Medicare perspective.

METHODS

By using individual patient-level data from the MOSAIC trial (median follow-up: 44.2 months), DFS and overall survival (OS) were estimated up to 4 years from randomization. DFS was extrapolated from 4 to 5 years by fitting a Weibull model and subsequent survival was estimated from life tables. OS beyond 4 years was predicted from the extrapolated DFS estimates and observed survival after recurrence. Costs were calculated from trial data and external estimates of resources to manage recurrence.

RESULTS

Patients on FOLFOX4 were predicted to gain 2.00 (95% confidence interval [CI]: 0.63, 3.37) years of DFS over those on 5-FU/LV. The predicted life expectancy of stage III patients on FOLFOX4 and 5-FU/LV was 17.61 and 16.26 years, respectively. Mean total lifetime disease-related costs were $56,300 with oxaliplatin and $39,300 with 5-FU/LV. Compared with 5-FU/LV, FOLFOX4 was estimated to cost $20,600 per life-year gained and $22,800 per quality-adjusted life-year (QALY) gained, discounting costs and outcomes at 3% per annum.

CONCLUSIONS

FOLFOX4 is likely to be cost-effective compared with 5-FU/LV in the adjuvant treatment of stage III colon cancer. The incremental cost-effectiveness ratio compares favorably with other funded interventions in oncology.

Oxaliplatin in the treatment of colorectal cancer

Significant advances in the treatment of colorectal cancer have been observed over the past several years. With the introduction of oxaliplatin combined with infusional 5-fluorouracil and leucovorin, survival for patients with metastatic colorectal cancer has nearly doubled. The incorporation of biologic agents that target angiogenesis (bevacizumab) and tumor growth pathways (cetuximab, panitumimab) extends survival even further, in addition to increasing response rates in patients with metastatic disease. The benefit of these newer drugs is also being realized in the adjuvant setting, where the addition of oxaliplatin to infusional 5-fluorouracil and leucovorin has led to improvements in 3-year disease-free survival. Future challenges with the use of oxaliplatin include defining strategies to optimize its use while avoiding treatment-limiting neurotoxicity and identification of markers predictive of response.

Adjuvant chemotherapy for colon cancer: evidence on improvement in survival

Clear progress has been made in the adjuvant treatment of colon cancer. Until very recently, the absolute benefit for survival obtained with the administration of 6 months' FU/LV compared with control was about 6%. Fluoropyrimidines have been shown to be at least as active and can replace intravenous FU/LV in stage III colon cancer. Based on the results of the MOSAIC and NSABP C-07 trials, the addition of oxaliplatin to FU/LV improves disease-free survival and FOLFOX for 6 months can be recommended as adjuvant treatment for patients with stage III colon cancer. The benefit of adjuvant chemotherapy in stage II disease is limited and it should be proposed in patients with high-risk features. Adjuvant treatment of colon cancer improving and the use of genetic/molecular markers with the new targeted therapies may further improve survival.

New approaches to the adjuvant therapy of colon cancer

Analysis of data from patients treated outside clinical trials suggests that adjuvant chemotherapy for stage II colon cancer provides less than a 3% absolute improvement in survival at 5 years. This is remarkably close to the small degree of benefit suggested by controlled studies. An overview of the data suggests that surgery alone cures approximately 75% of stage II patients. Between 20% and 25% of patients experience disease recurrence despite surgery and adjuvant chemotherapy, whereas adjuvant chemotherapy cures between 1% and 6%. In stage III patients, the benefit of adjuvant therapy is greater overall. The extent of benefit relates to tumor grade, invasion, and nodal involvement. Incorporation of molecular markers in the design of current trials may enable us to refine our identification of patients at highest risk of recurrence and hence those standing to gain most from adjuvant therapy.

New Agents, Combinations, and Opportunities in the Treatment of Advanced and Early-Stage Colon Cancer

There has been a dramatic improvement in outcomes for patients who have colon cancer over recent years. These improvements have come about largely because of the availability of new chemotherapy agents (irinotecan, oxaliplatin and capecitabine) and new biologic agents (bevacizumab and cetuximab). Large, well-designed clinical trials have resulted in the routine use of all of these agents in the treatment of patients who have metastatic disease, and this has led to improved survival for these patients. In earlier stage disease, oxaliplatin/5-FU-based chemotherapy has become a new standard of adjuvant therapy for many patients. Clinical research efforts are investigating the use of biologic agents along with chemotherapy for adjuvant treatment; it is hoped that this will translate into a greater cure rate for these patients.

Surgical adjuvant therapy for colorectal cancer: current approaches and future directions

Colon cancer is the fourth most common cancer worldwide. The role of systemic adjuvant chemotherapy in colorectal cancer patients with lymph node involvement has been established in a large number of clinical trials. However, its role in stage II colorectal cancer is less well established. 5-Fluorouracil has been the mainstay of therapy for the last four decades. With the development of novel chemotherapy and biological agents, we have entered into a new era for the treatment of colorectal cancer. The combination of adjuvant 5-fluorouracil, leucovorin, and oxaliplatin has been shown to significantly improve disease-free survival and is now considered the standard of care for completely resected colon cancer in healthy patients. For rectal cancer patients with locally advanced tumors, neoadjuvant chemoradiation followed by adjuvant chemotherapy after surgery is the mainstay of treatment. The availability of oral chemotherapy agents has helped with the ease of administration and avoidance of indwelling catheters. A number of national clinical trials are under way to determine the role of targeted agents in combination with chemotherapy. The goal is to develop a regimen that would improve survival without excessive toxicity while maintaining quality of life. Patients should be encouraged to participate in clinical trials whenever feasible. Despite the advances, many patients will develop recurrent disease. It is of utmost importance to develop molecular markers that could predict which patients are at high risk for disease recurrence. Clinical trials are under way to address this issue. Thus, it will be advantageous to be able to tailor therapy individually, according to the risk of recurrence.

Oxaliplatin-related neurotoxicity: how and why?

In early clinical trials, oxaliplatin has demonstrated significant activity against colorectal cancer in combination with 5-fluorouracil (5-FU) and folinic acid (FA), both in metastatic as in radically resected disease. The drug differs from the other two most important platinum compounds (cisplatin and carboplatin) for the absence of nephrotoxicity or for the reduced drug-induced ototoxicity. During its administration, two different types of neurological symptoms can be experienced: the first one occurs during or immediately after the end of the infusion and it appears as a transient peripheral sensory neuropathy manifesting as paresthesias and dysesthesia in the extremities sometimes accompanied by muscular contractions of the extremities or the jaw (triggered or enhanced by exposure to cold). The second one occurs after long-term administration of oxaliplatin presenting with deep sensory loss, sensory ataxia and functional impairment (similar to those observed with cisplatin). This type of neurotoxicity is usually late-onset and correlated with the cumulative-dose of oxaliplatin. The aim of this review is to analyse the mechanism underlying induction of neurotoxicity and the possible treatments to prevent and to treat it.

End Points for Adjuvant Therapy Trials: Has the Time Come to Accept Disease‐Free Survival as a Surrogate End Point for Overall Survival?

The intent of adjuvant therapy is to eradicate micro-metastatic residual disease following curative resection with the goal of preventing or delaying recurrence. The time-honored standard for demonstrating efficacy of new adjuvant therapies is an improvement in overall survival (OS). This typically requires phase III trials of large sample size with lengthy follow-up. With the intent of reducing the cost and time of completing such trials, there is considerable interest in developing alternative or surrogate end points. A surrogate end point may be employed as a substitute to directly assess the effects of an intervention on an already accepted clinical end point such as mortality. When used judiciously, surrogate end points can accelerate the evaluation of new therapies, resulting in the more timely dissemination of effective therapies to patients. The current review provides a perspective on the suitability and validity of disease-free survival (DFS) as an alternative end point for OS. Criteria for establishing surrogacy and the advantages and limitations associated with the use of DFS as a primary end point in adjuvant clinical trials and as the basis for approval of new adjuvant therapies are discussed.

Adjuvant chemotherapy in colorectal cancer: a joint analysis of randomised trials by the Nordic Gastrointestinal Tumour Adjuvant Therapy Group

Due to uncertainties regarding clinically meaningful gains from adjuvant chemotherapy after colorectal cancer surgery, several Nordic Groups in the early 1990s initiated randomised trials to prove or reject such gains. This report gives the joint analyses after a minimum 5-year follow-up. Between October 1991 and December 1997, 2 224 patients under 76 years of age with colorectal cancer stages II and III were randomised to surgery alone (n = 1 121) or adjuvant chemotherapy (n = 1 103) which varied between trials (5FU/levamisole for 12 months, n = 444; 5FU/leucovorin for 4-5 months according to either a modified Mayo Clinic schedule (n = 262) or the Nordic schedule (n = 397). Some centres also randomised patients treated with 5FU/leucovorin to+/-levamisole). A total of 812 patients had colon cancer stage II, 708 colon cancer stage III, 323 rectal cancer stage II and 368 rectal cancer stage III. All analyses were according to intention-to-treat. No statistically significant difference in overall survival, stratified for country or region, could be found in any group of patients according to stage or site. In colon cancer stage III, an absolute difference of 7% (p = 0.15), favouring chemotherapy, was seen. The present analyses corroborate a small but clinically meaningful survival gain from adjuvant chemotherapy in colon cancer stage III, but not in the other presentations.

Zukunft der Chemotherapie

The future development of chemotherapy is derived based upon recent advances. With regard to adjuvant therapy a trend towards standardized prediction of recurrence risk using all available prognostic markers (e.g., nomograms) is observed. Furthermore, in some tumors major progress has been made regarding the development of "molecular classifiers" defining tumor biology (predicting clinical outcome) by analysis of molecular changes. In adjuvant therapy considerable advances may be achieved by use of new chemotherapeutic agents as well as sequential, dose-dense and dose-intensified regimens. However, in metastatic disease no breakthrough can be expected at least with regard to survival suggesting that quality of life needs to be addressed with more emphasis. Using targeted drugs alone or in combination with chemotherapy advances concerning adjuvant therapy as well as metastatic disease are observed. Further targeted drugs have entered clinical development. However, clarification of the relation between detection of the target(s) and drug activity will fundamentally change current treatment concepts.

ADVANCES IN THE ADJUVANT TREATMENT OF COLORECTAL CANCER

BACKGROUND

There have been numerous advances in the adjuvant therapy of colon cancer in the last two decades.

METHODS

This review outlines the historical perspectives of adjuvant treatment as well as current and emerging standards of care.

RESULTS

Although previous regimens included a variety of equivalent schedules of 5-fluorouracil and folinic acid, integration of newer drugs such as oxaliplatin are offering significant improvements in disease-free survival. The use of targeted agents such as bevacuzimab creates the potential to further increase cure rates in the adjuvant setting. The current low rate of referral of eligible patients for chemotherapy in Australia is also discussed.

CONCLUSION

Adjuvant therapy for colon cancer is making major strides as we attempt to cure more patients.

Radiation therapy and combined modality treatment of gastrointestinal carcinomas

BACKGROUND

Ionizing radiation (IR) is a potent agent in enhancing tumor control of locally advanced cancer and has been shown to improve disease-free and overall survival in several entities. However, the role of radiotherapy (RT) in the treatment of gastrointestinal tumors remains controversial because of the marked radiation sensitivity of neighboring organs frequently compromising application of high doses of ionizing radiation.

METHODS

The Medline and the Cochrane Library from 1980 until 2005 were searched using subject heading (MeSH) terms including "esophageal neoplasm", "gastric neoplasm", "pancreatic neoplasm" and "rectal neoplasm", in combination with the subheadings "radiotherapy", "chemotherapy". The term, "randomized controlled trial", was used to identify randomized trials. The proceedings of the annual meeting of the American Society for Therapeutic Radiology and Oncology from 1999 to 2004 and the annual meeting of the American Society of Clinical Oncology from 1999 until 2005 were searched. Ongoing trials were identified through the Physician Data Query database (www.cancer.gov/search/clinical_trials).

RESULTS

RT in combination with surgery enhances tumor control of locally advanced cancer disease and has been shown to improve disease-free and overall survival in rectal cancer. In esophageal adenocarcinoma, survival was prolonged with pre-operative chemo-radiation in a meta-analysis. In gastric cancer, post-operative chemo-radiation can be considered after limited lymphadenectomy. Evidence for improving survival remains to be shown for pancreatic cancer and hepatobiliary carcinoma. In colon cancer, post-operative chemotherapy has proven to prolong survival. The impact of RT seems to be most prominent in the pre-operative setting in patients treated with curative intent.

CONCLUSIONS

Pre-operative RT or pre-operative chemo-radiation may be considered in individual cases, but should not be used routinely for gastro-intestinal carcinoma, except for rectal carcinoma. In many studies, pre-operative radiotherapy/chemo-radiation yielded promising results and merits validation in large controlled trials.

Adjuvant therapy in colon cancer--what, when and how?

Bolus fluorouracil and leucovorin has been accepted as the standard adjuvant therapy in stage III colon cancer for many years. New drugs such as irinotecan, oxaliplatin and oral fluoropyrimidines have all completed phase III randomised evaluation in colon cancer. Several of these studies have been reported in the last 24 months. Oxaliplatin-based chemotherapy is now emerging as the new standard of care in adjuvant treatment of stage III colon cancer. The advent of monoclonal antibodies such as cetuximab and bevacizumab has further broadened the treatment horizon for colorectal cancer and they are the focus of the on-going randomised studies in adjuvant therapy of colon cancer. In stage II colon cancer, adjuvant treatment remains controversial and is not routinely recommended in all medically fit patients by the current American Society of Clinical Oncology guidelines, except several subsets including poorly differentiated histology, T4 lesions, bowel perforation presentation and inadequately sampled lymph nodes (<13). This review focuses on the relative merits of these agents, their safety, duration of treatment, timing of commencing treatment after surgery and the role of adjuvant therapy in stage II colon cancer, thereby assisting clinicians in deciding the optimal adjuvant treatment for patients in routine clinical practice.

Rapid evolution in colorectal cancer: therapy now and over the next five years

A large number of patients with colorectal cancer have relatively early disease, and thus, adjuvant therapy has the potential to save lives. In stage III patients, there has been a steady improvement in 3-year disease-free survival with the use of 5-fluorouracil/leucovorin (5-FU/LV) regimens and capecitabine (Xeloda); Hoffmann-La Roche Inc., Nutley, NJ, http://www.rocheusa.com) regimens. A median survival longer than 20 months was observed in patients with metastatic disease when treated with combination chemotherapy containing oxaliplatin (Eloxatin); Sanofi-Synthelabo Inc., New York, http://www.sanofi-synthelabo.us) or irinotecan (Camptosar); Pfizer Pharmaceuticals, New York, http://www.pfizer.com). This has led to 5-FU/LV/oxaliplatin becoming standard therapy, along with 5-FU/LV/irinotecan. New data confirm the beneficial effect on disease-free survival of adding oxaliplatin to adjuvant colorectal cancer regimens based on 5-FU. These regimens show an effect when given in bolus as well as in infusional schedules. Interest in future adjuvant regimens focuses on the potential additional benefit of molecularly targeted agents, such as bevacizumab (Avastin); Genentech, Inc., South San Francisco, CA, http://www.gene.com), and on the ability of applied genomics to distinguish between high- and low-risk populations.

Guides for adjuvant treatment of colon cancer

The choice of the most suitable chemotherapy schedule for the adjuvant treatment of colon cancer has been reviewed by the TTD group, as well as the principles of risk assessment for patients with stage II disease. In the light of data now available, oxaliplatin- based schedules (FOLFOX4 or FLOX) are recommended. Alternatives in special situations are monotherapy with capecitabine, UFT/LV, or 5- FU/LV in infusion. In patients with stage II disease, the indication of chemotherapy must be individualized and based on the patient's risk of recurrence (perforation, obstruction, peritumoral lymphovascular involvement, poorly differentiated histology, number of lymph nodes examined < or = 11, pre-surgical CEA), and comorbidities that can compromise the safety of treatment or survival of the patient.

Adjuvant Therapy for Colon Cancer 2005: New Options in the Twenty-First Century

The most effective current regimen for adjuvant treatment of surgically resected stage III colon cancer is the FOLFOX regimen of oxaliplatin, 5-FU and LV for 12 weeks, with a proportional risk reduction of 45% compared with approximately 36% for 5-FU/LV regimens. Infusion regimens of 5-FU with and without LV have been shown to confer equivalent benefit to bolus regimens in reducing the risk of cancer recurrence, but with lesser toxicity profiles. Oral 5-FU prodrug regimens have similarly shown equivalent benefit to bolus regimens, and toxicity comparable to infusional regimens, but with the added convenience over 5-FU infusion therapy. The addition of irinotecan to 5-FU and LV regimens has not demonstrated an advantage compared with 5-FU/LV treatments in the adjuvant setting.

An Overview of Approaches to Adjuvant Therapy for Colorectal Cancer in the United States

Adjuvant chemotherapy for colon cancer and combined chemotherapy and radiation therapy (RT) for rectal cancer increases the proportion of patients cured of their disease. Adjuvant chemotherapy is indicated for stage III colon cancer, and although controversial for stage II disease, there is evidence to suggest that these patients may benefit as well. Adjuvant chemotherapy and RT is recommended for patients with stage II/III rectal cancer. Studies incorporating oral fluoropyrimidines as well as combination chemotherapy have been completed, with results demonstrating the value of these approaches. A new generation of studies will evaluate the biologic agents bevacizumab and cetuximab in the adjuvant therapy of colorectal cancer. For rectal cancer, optimal outcomes are dependent not only on the systemic therapy, but also on the expertise of the surgeon and the timing of RT, with improved local control and toxicity seen with preoperative therapy.