American Society of Clinical Oncology Recommendations on Adjuvant Chemotherapy for Stage II Colon Cancer

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.

Evolving role of antineoplastic agents in colorectal cancer

PURPOSE

The epidemiology, natural history, patient presentation, staging, prognosis, and treatment of colorectal cancer are described.

SUMMARY

Colorectal cancer is a common malignancy that usually is not diagnosed when it is localized because it typically is asymptomatic in the early stages. Various cancer chemotherapeutic agents with different toxicities are available, including the recently introduced recombinant humanized immunoglobulin G(1) monoclonal antibodies cetuximab and bevacizumab. Chemotherapy may be used with or without surgery in patients with advanced or metastatic colorectal cancer, usually for palliation rather than a cure. The results of clinical trials suggest that patients with advanced or metastatic colorectal cancer probably should receive 5-fluorouracil (5-FU)/leucovorin, irinotecan, oxaliplatin, bevacizumab, and cetuximab at some time in the course of treatment, although the preferred combinations and sequence of these agents remain to be determined. After surgery, adjuvant chemotherapy may be used for curative purposes in patients with stage III disease and some patients with stage II disease at high risk for disease recurrence and death. Although 5-FU plus leucovorin has been the standard adjuvant therapy, clinical trials have demonstrated that adding oxaliplatin or using capecitabine alone instead is an alternative.

CONCLUSION

Several recently introduced chemotherapeutic agents appear promising for the treatment of colorectal cancer, but additional clinical research is needed to identify the ideal combinations and sequence of these agents.

Medical malpractice in the age of technology: how specialty societies can make a difference

In the United States, medical malpractice litigation, and the rising cost of malpractice insurance, is a crisis that threatens to restrict patient access to high-risk services, especially obstetrics and certain surgical procedures. Radiation Oncology, though a small specialty, is very technologically oriented. Because the history of product liability and malpractice litigation in this country parallels the technologic revolution, practitioners of this specialty are clearly at risk for litigation. Because legislative relief is unlikely to be forthcoming in the near future, many specialty societies have assumed the responsibility for devising means to protect members from frivolous law suits, without compromising a patient's right to due process. To date, Radiation Oncology societies have not taken a leadership role in this movement, preferring instead to cede this responsibility to the American College of Radiology. Opportunities exist for specialty societies to define standards of care and establish guidelines for expert witness testimony. To date, the courts have been supportive of these efforts. Herein, we summarize some of the salient issues of the malpractice crisis facing Radiation Oncology and offer suggestions for change within the specialty to better address the malpractice problem.

Current issues in adjuvant treatment of stage II colon cancer

BACKGROUND

Adjuvant chemotherapy with 5-fluorouracil modulated by folinic acid, combined with oxaliplatin, has now become an accepted standard of care for patients with stage III colon cancer. In contrast, the use of adjuvant therapy for stage II patients remains controversial, and the identification of reliable prognostic factors to aid therapeutic decision making is crucial.

METHODS

The authors critically review the results of clinical trials and meta-analyses investigating the value of adjuvant chemotherapy for stage II patients, emphasizing the heterogeneous nature of this population and the difficulty of performing clinical trials with sufficient power to reliably assess treatment efficacy. They also discuss the evidence concerning potential prognostic factors, particularly molecular markers.

RESULTS

Available clinical trial data do not support the routine use of adjuvant chemotherapy for all stage II patients but suggest that it should be considered, particularly for certain high-risk patients. Recent guidelines advocate considering factors such as tumor differentiation, tumor perforation, number of lymph nodes examined, and T stage when assessing the likely benefit:risk ratio. Microsatellite instability and allelic imbalance seem to be strong predictors of good and poor prognosis, respectively, and in the near future, therapeutic decision-making models are likely to be further refined by the inclusion of such molecular markers.

CONCLUSIONS

There is growing evidence that the prognosis of certain stage II patients with unfavorable prognostic factors can be improved by adjuvant chemotherapy, and increasingly refined tools are now available to define those most likely to benefit. Referral of stage II patients for individual assessment is strongly recommended.

Epidemiology of treatment-associated mucosal injury after treatment with newer regimens for lymphoma, breast, lung, or colorectal cancer

GOALS OF WORK

Oral and gastrointestinal (GI) mucositis are frequent complications of chemotherapy and radiotherapy for cancer, contributing to not only the morbidity of treatment but its cost as well. The risk associated with specific chemotherapeutic agents, alone and in combination, has been characterized previously. In the current study, we sought to estimate the risk associated with newer regimens for the treatment of non-Hodgkin's lymphoma (NHL) and common solid tumors.

METHODS

We reviewed published studies reporting phase II and III clinical trials of dose-dense regimens for breast cancer and NHL, TAC (docetaxel, adriamycin, cyclophosphamide) chemotherapy for breast cancer, and infusional 5-fluorouracil-based regimens for colorectal cancer. Platinum-, gemcitabine-, and taxane-based regimens for lung cancer, either alone or in combination with radiotherapy, were also considered. Using modified meta-analysis methods, we calculated quality-adjusted estimates of the risk for oral and GI mucositis by tumor type and regimen. Case reports are used to emphasize the relevance of the findings for patient care.

MAIN RESULTS

Our findings demonstrate that mucosal toxicity remains an important complication of cancer treatment. Moreover, innovations in drug combinations, scheduling, or mode of administration significantly modulate the risk for both oral and GI mucositis.

CONCLUSIONS

Ongoing review of the clinical trial experience will remain important as newer, targeted agents enter standard clinical practice.

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.

Combined resection of the duodenum and pancreas for locally advanced colon cancer

Colorectal cancer invading adjacent organs is a frequent event occurring in 5.5% to 12% of all colorectal malignancies. Colon cancer directly invading the duodenum and pancreas is rare and may require combined resection of the colon, pancreas, and duodenum, which represents a complex operation with significant morbidity and mortality rates. In this article, a case of a 41-year-old patient with a right colon cancer directly infiltrating the duodenum and head of the pancreas is presented. The patient was treated by radical combined resection of the colon, duodenum, and pancreas. Pathological examination confirmed neoplastic invasion of the adjacent organs and absence of lymph node metastasis (T4N0). The patient recovered uneventfully. Patients with colorectal cancer infiltrating adjacent organs such as the duodenum and the pancreas should be treated by radical en bloc resection of the tumor. This procedure is the preferred treatment strategy because it seems to be associated with improved overall survival rates.

Chemotherapy and other systemic therapies for hepatocellular carcinoma and liver metastases

For hepatocellular carcinoma (HCC) that has advanced to the point that it is no longer amenable to local therapies, systemic therapy can be considered in select patients who have a good performance status. No systemic therapy has been clearly shown to improve overall survival compared with supportive care alone, although cancer-related symptoms can sometimes be palliated with therapy and some objective responses are seen. Systemic therapies for HCC include chemotherapy, both intravenous and infused via the hepatic artery, as well as hormonal therapy, immunotherapy, and targeted biologic agents. Colorectal, pancreatic, breast, and lung cancer are some of the most common tumors that metastasize to the liver. Response rates and effect on overall survival as a result of systemic therapy for liver metastases vary widely depending on primary tumor site. Targeted biologic agents are being integrated into standard treatment regimens for all of these cancer types, with variable effects on survival and other outcomes for all affected patients including those with liver metastases.

Identification of early-stage colorectal cancer patients at risk of relapse post-resection by immunobead reverse transcription-PCR analysis of peritoneal lavage fluid for malignant cells

PURPOSE

Colorectal cancer patients diagnosed with stage I or II disease are not routinely offered adjuvant chemotherapy following resection of the primary tumor. However, up to 10% of stage I and 30% of stage II patients relapse within 5 years of surgery from recurrent or metastatic disease. The aim of this study was to determine if tumor-associated markers could detect disseminated malignant cells and so identify a subgroup of patients with early-stage colorectal cancer that were at risk of relapse.

EXPERIMENTAL DESIGN

We recruited consecutive patients undergoing curative resection for early-stage colorectal cancer. Immunobead reverse transcription-PCR of five tumor-associated markers (carcinoembryonic antigen, laminin gamma2, ephrin B4, matrilysin, and cytokeratin 20) was used to detect the presence of colon tumor cells in peripheral blood and within the peritoneal cavity of colon cancer patients perioperatively. Clinicopathologic variables were tested for their effect on survival outcomes in univariate analyses using the Kaplan-Meier method. A multivariate Cox proportional hazards regression analysis was done to determine whether detection of tumor cells was an independent prognostic marker for disease relapse.

RESULTS

Overall, 41 of 125 (32.8%) early-stage patients were positive for disseminated tumor cells. Patients who were marker positive for disseminated cells in post-resection lavage samples showed a significantly poorer prognosis (hazard ratio, 6.2; 95% confidence interval, 1.9-19.6; P = 0.002), and this was independent of other risk factors.

CONCLUSION

The markers used in this study identified a subgroup of early-stage patients at increased risk of relapse post-resection for primary colorectal cancer. This method may be considered as a new diagnostic tool to improve the staging and management of colorectal cancer.

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 treatment strategies for early colon cancer

Colon cancer remains a major cause of death; however, in the last 3 years a number of trials have been published that have led to changes in the treatment of patients with this disease. Initially, the adjuvant treatment of patients following curative resection was based on their Dukes staging; this is now being refined by consideration of other pathological factors, as well as the investigation of newer prognostic markers such as p53, Ki67 and a number of genes on chromosome 18. Tumours generally develop from the progressive accumulation of genetic events, although some develop through mutation or inactivation of DNA mismatch repair proteins leading to microsatellite instability; this is particularly important in Lynch's syndrome. The loss of gene expression can occur by deletion or mutation of genes or by aberrant methylation of CpG islands. In patients with Dukes C colon cancer the standard of care for adjuvant chemotherapy was previously based on bolus fluorouracil (5-fluorouracil) and folinic acid (leucovorin) administered 5 days per month or weekly for 6 months. Recent studies with a combination of infusional fluorouracil, folinic acid and oxaliplatin have been found to be superior. A further study replacing fluorouracil with oral capecitabine has also demonstrated equivalent disease-free survival. Although some debate remains regarding the benefit of adjuvant treatment for patients with Dukes B colon cancer, the emerging consensus is that, for those patients who are younger and have high-risk features, chemotherapy should be discussed. A number of large vaccine trials have also been conducted in the adjuvant setting and, overall, these have been disappointing. This is a rapidly advancing area of therapy and the results of new trials are awaited to determine whether additional benefits can be achieved with biological therapies such as anti-vascular endothelial growth factor and anti-epithelial growth factor receptor monoclonal antibodies, which have already been shown to be effective in setting of metastatic colon cancer.

Analysis of apoptosis protein expression in early-stage colorectal cancer suggests opportunities for new prognostic biomarkers

PURPOSE

Although most stage II colon cancers are potentially curable by surgery alone, approximately 20% of patients relapse, suggesting a need for establishing prognostic markers that can identify patients who may benefit from adjuvant chemotherapy. We tested the hypothesis that differences in expression of apoptosis-regulating proteins account for differences in clinical outcome among patients with early-stage colorectal cancer.

EXPERIMENTAL DESIGN

Tissue microarray technology was employed to assay the expression of apoptosis-regulating proteins by immunohistochemistry in 106 archival stage II colorectal cancers, making correlations with disease-specific survival. The influence of microsatellite instability (MSI), tumor location (left versus right side), patient age, and gender was also examined.

RESULTS

Elevated expression of several apoptosis regulators significantly correlated with either shorter (cIAP2; TUCAN) or longer (Apaf1; Bcl-2) overall survival in univariate and multivariate analyses. These biomarkers retained prognostic significance when adjusting for MSI, tumor location, patient age, and gender. Moreover, certain combinations of apoptosis biomarkers were highly predictive of death risk from cancer. For example, 97% of patients with favorable tumor phenotype of cIAP2(low) plus TUCAN(low) were alive at 5 years compared with 60% of other patients (P = 0.00003). In contrast, only 37% of patients with adverse biomarkers (Apaf1(low) plus TUCAN(high)) survived compared with 83% of others at 5 years after diagnosis (P< 0.0001).

CONCLUSIONS

Immunohistochemical assays directed at detection of certain combinations of apoptosis proteins may provide prognostic information for patients with early-stage colorectal cancer, and therefore could help to identify patients who might benefit from adjuvant chemotherapy or who should be spared it.

Inclusion of Vasculature-Related Variables in the Dukes Staging System of Colon Cancer

PURPOSE

The Dukes stage is used to stratify colorectal cancer patients into groups of different prognosis and need of adjuvant radiotherapy and chemotherapy. However, approximately 80% of patients with Dukes stage C colorectal cancer receive cytotoxic therapy without any expected benefit, for such patients would either not relapse without adjuvant therapy or they would inevitably do so because of tumor resistance to the available regimens. On the other hand, as 20% of Dukes stage B patients would relapse after surgery, adjuvant therapy could improve their survival. Improvement of the Dukes stage predictive accuracy is necessary to better assign patients for adjuvant therapies, especially nowadays when antiangiogenic agents are being incorporated in the clinical practice.

PATIENTS AND METHODS

In this study, we examined the prognostic role of Dukes staging system in parallel with three vasculature-related variables (vascular invasion, tumor angiogenic activity, and vascular survival ability) in a series of 130 stage B/C patients with colorectal cancer treated with surgery alone (without adjuvant radiotherapy or chemotherapy).

RESULTS

Inclusion of vasculature-related variables in the Dukes staging system significantly improved the prognostic categorization of patients, identifying subgroups of B-stage and C-stage patients with an up to 40% and 60% 5-year survival difference, respectively.

CONCLUSIONS

Preliminary results show that the prognostic value of Dukes staging system is significantly improved after taking into account vasculature-related variables, which may be useful in stratifying patients for adjuvant therapies, highlighting also subgroups that may benefit the most from antiangiogenic agents.

Cancer staging and survival in colon cancer is dependent on the quality of the pathologists' specimen examination

Correct staging of colon cancer is decisive regarding further oncological treatment, surveillance and prediction of long-term survival. This study investigated the variability in accuracy of pathology reports with focus on differences between pathology departments and their compliance to regional guidelines. Data from the colon cancer register (1997-2002) of the Uppsala/Orebro, Sweden, health care region were analysed and the seven pathology departments in this region were compared. Included were 3735 patients who had undergone resection of a colon cancer. Cumulative 5-year survival was the main end-point. For 64% (n = 2390) of the cases, the number of lymph nodes examined was given (median 8). Survival in stage II was lower when fewer than 12 nodes were examined or when the number of nodes sampled was not given (P = 0.001, log-rank test). In stage III, those with at the most 3 nodes positive (N1) had a better survival than those with 4 or more nodes positive (N2) (P < 0.001, log-rank test). An index of metastases (IM), derived from the number of nodes with metastases divided by the number of nodes examined, was calculated for stage III tumours. Examination of 12 nodes is necessary to assure stage III cases with the median IM (0.32), whereas 20 nodes are necessary to assure 90% of cases with the lower quartile of IM (0.16). Irrespective of the number of nodes investigated, overall survival was better among patients with IM < 0.33 vs. IM > or = 33 (P < 0.001, log-rank test). The prognostic information of the IM was higher than that of the N-stage. Quality of a pathology department, measured by the median number of lymph nodes investigated and by the proportion of reports where the number is given, was determined to indicate correct staging and management of the patient. An index of metastases (IM) is a possible basis for guidance in the choice of adjuvant treatments that appears superior to that of N-stage.

A systematic review and meta-analysis of the relationship between chromosome 18q genotype, DCC status and colorectal cancer prognosis

Results from studies investigating the relationship between colorectal cancer survival and chromosome 18q allelic imbalance (AI)/loss of DCC expression (LOE) have been inconsistent. We have reviewed and pooled published studies to estimate the prognostic significance of chromosome 18q status more precisely. Data from 27 studies were eligible. Survival data were pooled using standard meta-analysis techniques. Considerable variation between assessment method, marker choice, and threshold for assigning AI/LOE was observed. Pooling data from a 2189 cases from 17 studies showed significantly worse overall survival in patients with AI/LOE (HR = 2.00, 95%CI: 1.49-2.69), maintained both in the adjuvant setting (HR = 1.69, 95%CI:1.13-2.54), and also by method (HR = 1.67, 95%CI: 1.19-2.36, genotyping microsatellites; HR = 3.00, 95%CI: 1.98-4.56, immunohistochemistry). There was however evidence of heterogeneity and publication bias. Cancers with chromosome 18q loss appear to have a poorer prognosis. Prospective studies using consistent methodology are needed to precisely quantify its effect and role in patients with stage II-III disease.

Routine testing for mismatch repair deficiency in sporadic colorectal cancer is justified

This study prospectively examines the accuracy of immunohistochemical staining in the identification of mismatch repair defective (MMRD) colorectal cancer in routine clinical practice. The potential impact of this information on decisions regarding adjuvant treatment and germline testing were quantified. A consecutive series of fresh tissue (836 cancers) was obtained from 786 individuals undergoing curative surgery for colorectal cancer at one institution. As part of normal practice, each tumour was screened for the expression of MLH1 and MSH2 by immunohistochemical staining (IHC) and relevant clinicopathological details were documented. Microsatellite instability (MSI) was assessed using standard markers. Overall, 108 (13%) tumours showed loss of staining for either MLH1 (92 tumours) or MSH2 (16 tumours). The positive predictive value of mismatch repair IHC when used alone in the detection of MSI tumours was 88%, and the negative predictive value was 97%. Specificity and positive predictive value were improved by correlation with microsatellite status. Tumour stage (HR 3.5, 95% CI 2.0-6.0), vascular space invasion (HR 1.9, 95% CI 1.2-3.0) and mismatch repair deficiency (HR 0.2, 95% CI 0.05-0.87) were independent prognostic factors in stages II and III disease. Screening by mismatch repair IHC could reasonably have been expected to prevent ineffective treatment in 3.6% of stage II and 7.6% of stage III patients. The frequency of germline mismatch repair mutations was 0.8%, representing six unsuspected hereditary non-polyposis colorectal cancer (HNPCC) cases. Routine screening of colorectal cancers by mismatch repair IHC identifies individuals at low risk of relapse, and can prevent unnecessary adjuvant treatments in a significant number of individuals. Abnormal immunohistochemistry should be confirmed by microsatellite testing to ensure that false-positive results do not adversely impact on treatment decisions.

Adjuvant therapy for colon cancer

As there have been advances in the treatment of metastatic colorectal cancer, exciting developments have also been achieved in the adjuvant treatment of colon cancer. At the same time, more questions have been raised, and some controversies remain. The results of the MOSAIC trial demonstrated the benefit of adding oxaliplatin to 5-fluorouracil (5-FU) and leucovorin (FOLFOX) in adjuvant therapy for stage II and III disease, but the optimal duration of therapy and the management of toxicities remain to be resolved. Capecitabine is at least equivalent to the Mayo Clinic bolus 5-FU and leucovorin regimen in the adjuvant treatment of stage III colon cancer with a lower incidence profile of adverse events, allowing additional options for patients and physicians. Routine adjuvant systemic therapy in all patients with stage II colon cancer is still debatable. Although a statistically significant advantage for adjuvant treatment in stage II disease was shown for the first time from a large randomized study (QUASAR), the subsets of patients who truly benefit from therapy need to be identified. The application of pharmacogenetics and pharmacogenomics in adjuvant therapy for colorectal cancer will help to distinguish those patients with risk factors and to guide individualized therapy.

Disease-free survival versus overall survival as a primary end point for adjuvant colon cancer studies: individual patient data from 20,898 patients on 18 randomized trials

PURPOSE

A traditional end point for colon adjuvant clinical trials is overall survival (OS), with 5 years demonstrating adequate follow-up. A shorter-term end point providing convincing evidence to allow treatment comparisons could significantly speed the translation of advances into practice.

METHODS

Individual patient data were pooled from 18 randomized phase III colon cancer adjuvant clinical trials. Trials included 43 arms, with a pooled sample size of 20,898 patients. The primary hypothesis was that disease-free survival (DFS), with 3 years of follow-up, is an appropriate primary end point to replace OS with 5 years of follow-up.

RESULTS

The recurrence rates for years 1 through 5 were 12%, 14%, 8%, 5%, and 3%, respectively. Median time from recurrence to death was 12 months. Eighty percent of recurrences were in the first 3 years; 91% of patients with recurrence by 3 years died before 5 years. Correlation between 3-year DFS and 5-year OS was 0.89. Comparing control versus experimental arms within each trial, the correlation between hazard ratios for DFS and OS was 0.92. Within-trial log-rank testing using both DFS and OS provided the same conclusion in 23 (92%) of 25 cases. Formal measures of surrogacy were satisfied.

CONCLUSION

In patients treated on phase III adjuvant colon clinical trials, DFS and OS are highly correlated, both within patients and across trials. These results suggest that DFS after 3 years of median follow-up is an appropriate end point for adjuvant colon cancer clinical trials of fluorouracil-based regimens, although marginally significant DFS improvements may not translate into significant OS benefits.

Modulation of 5-fluorouracil as adjuvant systemic chemotherapy in colorectal cancer: the IGCS-COL multicentre, randomised, phase III study

The aims of this multicentre, randomised phase III trial were to evaluate: (1) the role of levamisol (LEV); and (2) the role of folinic acid (FA), added to 5-fluorouracil (5FU) in the adjuvant treatment of colorectal cancer. Patients with histologically proven, radically resected stage II or III colon or rectal cancer were eligible. The study had a 2x2 factorial design with four treatment arms: (a) 5FU alone, (b) 5FU+LEV, (c) 5FU+FA, (d) 5FU+LEV+FA, and two planned comparisons, testing the role of LEV and of FA, respectively. From March 1991, to September 1998, 1327 patients were randomised. None of the two comparisons resulted in a significant disease-free (DFS) or overall (OAS) survival advantage. The hazard ratio (HR) of relapse was 0.89 (95% confidence intervals (CI): 0.73-1.09) for patients receiving FA and 0.99 (95% CI 0.80-1.21) for those receiving LEV; corresponding HRs of death were 1.02 (95% CI: 0.80-1.30) and 0.94 (95% CI 0.73-1.20). Nonhaematological toxicity (all grade vomiting, diarrhoea, mucositis, congiuntivitis, skin, fever and fatigue) was significantly worse with FA, while all other toxicities were similar. In the present trial, there was no evidence that the addition of FA or LEV significantly prolongs DFS and OAS of radically resected colorectal cancer patients.

Colon cancer prognosis prediction by gene expression profiling

This study assessed the possibility to build a prognosis predictor, based on microarray gene expression measures, in stage II and III colon cancer patients. Tumour (T) and non-neoplastic mucosa (NM) mRNA samples from 18 patients (nine with a recurrence, nine with no recurrence) were profiled using the Affymetrix HGU133A GeneChip. The k-nearest neighbour method was used for prognosis prediction using T and NM gene expression measures. Six-fold cross-validation was applied to select the number of neighbours and the number of informative genes to include in the predictors. Based on this information, one T-based and one NM-based predictor were proposed and their accuracies were estimated by double cross-validation. In six-fold cross-validation, the lowest numbers of informative genes giving the lowest numbers of false predictions (two out of 18) were 30 and 70 with the T and NM gene expression measures, respectively. A 30-gene T-based predictor and a 70-gene NM-based predictor were then built, with estimated accuracies of 78 and 83%, respectively. This study suggests that one can build an accurate prognosis predictor for stage II and III colon cancer patients, based on gene expression measures, and one can use either tumour or non-neoplastic mucosa for this purpose.

Advances in Treatment of Colorectal Cancer

The purpose of this review is to provide the practicing surgeon with an outline of several significant developments in colorectal cancer treatment that have affected the care of patients. This review is not intended to report on every important publication of the past few years nor is it intended to be encyclopedic. The author simply hopes to provide a useful reference for surgeons in their daily practice.

Identification of a novel synthetic thiazolidin compound capable of inducing c-Jun NH2-terminal kinase-dependent apoptosis in human colon cancer cells

Development of new therapeutic agents for colon cancer is highly desirable. To this end, we screened a chemical library for new anticancer agents and identified a synthetic compound, 5-(2,4-dihydroxybenzylidene)-2-(phenylimino)-1,3-thiazolidin (DBPT), which kills cancer cells more effectively than it kills normal human fibroblasts. The molecular mechanism of the antitumor action of DBPT was further analyzed in three human colorectal cancer cell lines. DBPT effectively inhibited the growth of colorectal cancer cells, independent of p53 and P-glycoprotein status, whereas normal fibroblasts were unaffected at the same IC50. Over time, DLD-1 cancer cells treated with DBPT underwent apoptosis. The general caspase inhibitor benzyloxycarbonyl-valine-alanine-aspartate-fluoromethylketone partially blocked DBPT-induced apoptosis in a dose-dependent manner. DBPT-induced apoptosis, including cytochrome c release and caspase activation, was abrogated when c-Jun NH2-terminal kinase (JNK) activation was blocked with either a specific JNK inhibitor or a dominant-negative JNK1 gene. However, constitutive JNK activation alone did not replicate the effects of DBPT in DLD-1 cells, and excessive JNK activation by adenovirus encoding MKK7 had little influence on DBPT-induced apoptosis. Our results suggested that DBPT induces apoptosis in colorectal cancer cell lines through caspase-dependent and caspase-independent pathways and that JNK activation was crucial for DBPT-induced apoptosis. DBPT and its analogues might be useful as anticancer agents.

[5-Fluorouracil-induced small bowel toxicity in a patient with colorectal cancer]

5-Fluorouracil-induced gastro-intestinal toxicity predominantly affects the upper and the lower gastro-intestinal tract. Although 5-fluorouracil (5-FU) can cause severe small-bowel toxicity, this has been reported only in 6 patients with colon carcinoma receiving 5-FU-based therapy. The presentation was extensive ulceration and inflammation of the small bowel with no involvement of the colon. We report another case of this toxicity, and discuss the diagnosis and mechanisms by which 5-FU can induce small-bowel toxicity.

Adjuvant therapy of colon cancer: current status and future developments

Options for the adjuvant therapy of resected stage III colon cancer have expanded beyond the previously well-accepted standard of 5-fluorouracil (5-FU) combined with leucovorin. The Xeloda in Adjuvant Colon Cancer Therapy (X-ACT) study confirmed that capecitabine (Xeloda) is at least as effective and is less toxic than a bolus 5-FU and leucovorin regimen for patients with stage III colon cancer. This study, in addition to National Surgical Adjuvant Breast and Bowel Project (NSABP) C-06, which demonstrated the equivalence of tegafur-uracil (UFT)/leucovorin with 5-FU/leucovorin, provides support for use of oral fluoropyrimidines for adjuvant therapy. Support for use of multiagent chemotherapy has been provided by the European MOSAIC study, which demonstrated a significant improvement in 3-year disease-free survival for the addition of oxaliplatin (Eloxatin) to infusional 5-FU and leucovorin (FOLFOX). Although adding irinotecan (Camptosar) to a bolus 5-FU and leucovorin regimen did not improve outcome in the adjuvant setting, the PETACC studies are evaluating the combination of infusional 5-FU, leucovorin, and irinotecan. In contrast to agreement on the appropriateness of therapy for stage III colon cancer, adjuvant therapy for patients with stage II disease remains controversial. Future advances in adjuvant therapy may include targeted therapies. Based on data demonstrating efficacy for the monoclonal antibodies bevacizumab (Avastin) and cetuximab (Erbitux) in the metastatic setting, clinical trials adding these agents to standard chemotherapy have been initiated in the adjuvant setting. Specifically, one U.S. cooperative group trial will evaluate the addition of bevacizumab to chemotherapy, a second will assess the addition of cetuximab, and a third trial will evaluate FOLFOX, infusional 5-FU/leucovorin (FOLFIRI), and FOLFOX followed by FOLFIRI. Finally, a study for patients with stage II disease and adverse prognostic factors will open. An important consideration in the new clinical trials is an assessment of molecular markers that either predict response or resistance to therapy or provide other prognostic information.

Adjuvant chemotherapy for stage II colorectal cancer: the time is right!

Colorectal cancer is the second most common cause of cancer death in much of the developed world. Cancer-related mortality is slowly decreasing as a result of better detection and improved surgery. Adjuvant chemotherapy is now considered the standard treatment for stage III colon cancer, and has evolved recently with the introduction of infusional, combination chemotherapy. Adjuvant therapy for stage II colon cancer has been more controversial. Recent trial data suggest, however, that there is a legitimate case for discussing the advantages and limitations with individual patients.

Capecitabine as adjuvant treatment for stage III colon cancer

BACKGROUND

Intravenous bolus fluorouracil plus leucovorin is the standard adjuvant treatment for colon cancer. The oral fluoropyrimidine capecitabine is an established alternative to bolus fluorouracil plus leucovorin as first-line treatment for metastatic colorectal cancer. We evaluated capecitabine in the adjuvant setting.

METHODS

We randomly assigned a total of 1987 patients with resected stage III colon cancer to receive either oral capecitabine (1004 patients) or bolus fluorouracil plus leucovorin (Mayo Clinic regimen; 983 patients) over a period of 24 weeks. The primary efficacy end point was at least equivalence in disease-free survival; the primary safety end point was the incidence of grade 3 or 4 toxic effects due to fluoropyrimidines.

RESULTS

Disease-free survival in the capecitabine group was at least equivalent to that in the fluorouracil-plus-leucovorin group (in the intention-to-treat analysis, P<0.001 for the comparison of the upper limit of the hazard ratio with the noninferiority margin of 1.20). Capecitabine improved relapse-free survival (hazard ratio, 0.86; 95 percent confidence interval, 0.74 to 0.99; P=0.04) and was associated with significantly fewer adverse events than fluorouracil plus leucovorin (P<0.001).

CONCLUSIONS

Oral capecitabine is an effective alternative to intravenous fluorouracil plus leucovorin in the adjuvant treatment of colon cancer.

Adjuvant treatment of colorectal cancer

Colorectal cancer is one of the most frequent causes of cancer deaths. Survival for locoregional colorectal cancer is about 70% overall and 30-60% in stage III patients. Several randomized trials have shown that adjuvant chemotherapy can increase this survival rate. 5-Fluorouracil-based chemotherapy is strongly recommended in this context. There are still some questions about the setting in which patients should be treated as well as the optimal treatment. New data for different schedules and combinations are now available. Physicians have to choose between the different options now available to offer the best treatment to their patients. This Review analyses the current options for adjuvant therapy in colon and rectal cancer.

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.

Adjuvant therapy of colon cancer

Although surgical resection is still the only curative maneuver in the treatment of colon cancer, efforts of the past decades have proved that systemic chemotherapy in the adjuvant setting definitely improves the curative rate for those patients with localized colon cancer. The combination of the 5-fluorouracil (5-FU) and leucovorin (LV) remains the reference treatment. However, the advantage of infusional 5-FU/LV with oxaliplatin (FOLFOX) as adjuvant treatment may change the paradigm soon. Capecitabine may be considered as an alternative to 5-FU/LV in the adjuvant therapy of stage III colon cancer. The clinical benefit of adjuvant chemotherapy for localized node negative (stage II) disease is definite but small, even though there is yet no universal consensus. Novel molecular and biologic-oriented agents are being studied. Further analysis and definition of prognostic and predictive markers may allow future adjuvant therapy to be individualized.

Systematic review of microsatellite instability and colorectal cancer prognosis

PURPOSE

A number of studies have investigated the relationship between microsatellite instability (MSI) and colorectal cancer (CRC) prognosis. Although many have reported a better survival with MSI, estimates of the hazard ratio (HR) among studies differ. To derive a more precise estimate of the prognostic significance of MSI, we have reviewed and pooled data from published studies.

METHODS

Studies stratifying survival in CRC patients by MSI status were eligible for analysis. The principal outcome measure was the HR. Data from eligible studies were pooled using standard techniques.

RESULTS

Thirty-two eligible studies reported survival in a total of 7,642 cases, including 1,277 with MSI. There was no evidence of publication bias. The combined HR estimate for overall survival associated with MSI was 0.65 (95% CI, 0.59 to 0.71; heterogeneity P = .16; I(2) = 20%). This benefit was maintained restricting analyses to clinical trial patients (HR = 0.69; 95% CI, 0.56 to 0.85) and patients with locally advanced CRC (HR = 0.67; 95% CI, 0.58 to 0.78). In patients treated with adjuvant fluorouracil (FU) CRCs with MSI had a better prognosis (HR = 0.72; 95% CI, 0.61 to 0.84). However, while data are limited, tumors with MSI derived no benefit from adjuvant FU (HR = 1.24; 95% CI, 0.72 to 2.14).

CONCLUSION

CRCs with MSI have a significantly better prognosis compared to those with intact mismatch repair. Additional studies are needed to further define the benefit of adjuvant chemotherapy in locally advanced tumors with MSI.

Which drug combination for colorectal cancer?

In Westernised countries, colorectal cancer (CRC) is second only to lung cancer as a cause of death from malignancy, with only 60% of patients alive at 5 years. In Stage II/III CRC, where the standard treatment is 5-fluorouracil (5-FU)/leucovorin, a recent clinical trial has shown that with the addition of oxaliplatin, fewer patients have relapsed or died at 40 months follow-up. The benefit was more pronounced in patients with Stage III than II CRC, and the addition of oxaliplatin to 5-FU/leucovorin should be considered in Stage III CRC. In metastatic CRC, where the standard treatment is 5-FU/leucovorin/irinotecan, a recent clinical trial has shown that the addition of bevacizumab, a mAb, to vascular endothelial growth factor, prolonged progression-free and overall survival. Bevacizumab is likely to become part of the standard therapy for metastatic CRC.

A randomised comparison between 6 months of bolus fluorouracil/leucovorin and 12 weeks of protracted venous infusion fluorouracil as adjuvant treatment in colorectal cancer

BACKGROUND

We performed a multicentre randomised trial to compare the efficacy and toxicity of 12 weeks of protracted venous infusion (PVI) 5-fluorouracil (5-FU) against the standard bolus monthly regimen of 5-FU/leucovorin (LV) given for 6 months as adjuvant treatment in colorectal cancer (CRC).

PATIENTS AND METHODS

Patients with curatively resected stage II and III CRC were randomly assigned to 5-FU/LV [5-FU 425 mg/m(2) intravenously (i.v.) and LV 20 mg/m(2) i.v. bolus days 1-5 every 28 days for 6 months] or to PVI 5-FU (300 mg/m(2)/day for 12 weeks).

RESULTS

Between 1993 and 2003, 801 eligible patients were randomised to 5-FU/LV (n=404) or PVI 5-FU (n=397). With a median follow-up of 5.3 years, 231 relapses and 220 deaths have been observed. Five-year relapse-free survival (RFS) was 66.7% [95% confidence interval (CI) 61.6% to 71.3%] and 73.3% (95% CI 68.4% to 77.6%) with bolus 5-FU/LV and PVI 5-FU, respectively [hazard ratio (HR) 0.8; 95% CI 0.62-1.04; P=0.10]. Five-year overall survival (OS) was 71.5% (95% CI 66.4% to 75.9%) and 75.7% (95% CI 70.8% to 79.9%) with bolus 5-FU/LV and PVI 5-FU, respectively (HR 0.79; 95% CI 0.61-1.03; P=0.083). There was a significant survival advantage for patients starting adjuvant chemotherapy within 8 weeks (P=0.044). Significantly less diarrhoea, stomatitis, nausea and vomiting, alopecia, lethargy, and neutropenia (all with P <0.0001) were seen with PVI 5-FU.

CONCLUSIONS

There was no OS difference between the two arms, although PVI 5-FU was associated with a trend towards better RFS and OS compared with bolus 5-FU/LV, as well as significantly less toxicity. Based on our results, the probability of 12 weeks of PVI 5-FU being inferior to 6 months of bolus 5-FU/LV is extremely low (P <0.005), and therefore shorter duration of adjuvant treatment should be explored further.

Colorectal cancer

Every year, more than 945000 people develop colorectal cancer worldwide, and around 492000 patients die. This form of cancer develops sporadically, in the setting of hereditary cancer syndromes, or on the basis of inflammatory bowel diseases. Screening and prevention programmes are available for all these causes and should be more widely publicised. The adenoma-carcinoma sequence is the basis for development of colorectal cancer, and the underlying molecular changes have largely been identified. Prognosis depends on factors related to the patient, treatment, and tumour, and the expertise of the treatment team is one of the major determinants of outcome. New information on the molecular basis of this cancer have led to the development of targeted therapeutic options, which are being tested in clinical trials. Further clinical progress will largely depend on the broader implementation of multidisciplinary treatment strategies following the principles of evidence-based medicine.

Retention of chromosome arm 5q in stage II colon cancers identifies 83% of liver metastasis occurrences

The decision to use chemotherapy in the treatment of colon cancer patients depends on the risk of developing metastases, as estimated by clinicopathological staging combining body imaging and pathological findings. The aim of this study was to identify all chromosome arms that, when allelotyped, correlate with the metastatic process, add prognostic information to pathology, and are of relevance for predicting metachronous metastases. A 5-year follow-up survey enrolled 401 MSS (microsatellite stable) colon cancer patients who were divided into three groups. Staging was performed with and without imaging data (called tumor and patient staging, respectively). The first 192 patients were used to construct a model prognosticating metastases. The subsequent 146 patients were used to validate this model. The third group evaluated its consistency by comparing the status of the relevant chromosome arms in 63 liver metastases and primary tumors that did or did not metastasize. The first group identified three factors: tumor staging (P < 0.0001), 5q status (P = 0.003), and gender (P = 0.02). The second group confirmed 5q as a marker of metastasis occurrence (P = 0.004). Merged data predicted that, when both 5q arms are retained, metastatic risk increases 4.3-fold in stage II patients. The third group corroborated these findings, with a 5q retention rate in metastases comparable to that of primary tumors that metastasize, but significantly higher than that observed in nonmetastatic tumors (one-tail, P = 0.0005). Long arm of chromosome 5 allelotyping detects high-risk stage II tumors. This simple, easily implemented, and inexpensive test increases the power of randomized studies that evaluate chemotherapy.

Oxaliplatin

Oxaliplatin is available in numerous countries for the treatment of metastatic colorectal cancer (in conjunction with fluoropyrimidine therapy). The activity of oxaliplatin in advanced disease has led to investigation of its potential in operable disease. The addition of oxaliplatin to adjuvant therapy with fluorouracil and folinic acid (FOLFOX4 regimen) is associated with a significantly greater disease-free survival at 3 years (78% vs 73%; p = 0.002), according to results of the MOSAIC (Multicenter International Study of Oxaliplatin/5FU/Leucovorin [folinic acid] in the Adjuvant Treatment of Colon Cancer) trial, a study in 2246 patients with stage II or III colon cancer. In addition, a 23% reduction in the risk of disease recurrence after surgery was seen with FOLFOX4 compared with fluorouracil/folinic acid in the MOSAIC trial. Results from several phase I/II studies suggest that the addition of oxaliplatin to preoperative radiochemotherapy may be of benefit in patients with locally advanced lower rectal cancer in terms of disease downstaging and sphincter preservation. Oxaliplatin was generally well tolerated in the MOSAIC trial and neuro- and myelotoxicity with FOLFOX4 were manageable.