Randomized clinical trial of adjuvant radiotherapy and 5-fluorouracil infusion in colorectal cancer (AXIS)

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.

Randomized Controlled Trial of Intraportal Chemotherapy Combined With Adjuvant Chemotherapy (mFOLFOX6) for Stage II and III Colon Cancer

OBJECTIVES

The optimal time to initiate adjuvant chemotherapy after surgery in patients with colon cancer is not clear. We investigated the benefit of combined intraportal chemotherapy administered during radical surgery with adjuvant chemotherapy for treating stage II and III colon cancer.

METHODS

Patients were randomly assigned to OCTREE arm (intraportal chemotherapy plus mFOLFOX6) or a standard adjuvant chemotherapy arm (mFOLFOX6). The primary study endpoint was disease-free survival. The secondary endpoints included metastasis-free survival, overall survival, and safety.

RESULTS

The intent-to-treat population comprised 237 patients. With a median follow-up of 44 months, the hazard ratio (OCTREE vs mFOLFOX6) was 0.66 (95% confidence interval, 0.43-0.90), a 34% risk reduction in favor of OCTREE (P = 0.016). The 3-year disease-free survival rate was 85.2% for OCTREE and 75.6% for mFOLFOX6 alone (P = 0.030). The 3-year metastasis-free survival rates were 87.6% for OCTREE and 78.0% for mFOLFOX6 (P = 0.035). Patients had lower distant metastatic rate in the OCTREE arm (12.7% vs 22.7%; P = 0.044), when compared with the mFOLFOX6 arm. The 3-year overall survival was no significant difference between 2 arms (P = 0.178). Neutropenia occurred in 12.7% of the patients receiving OCTREE and in 2.5% of the patients receiving mFOLFOX6 (P = 0.003) within 2 weeks of surgery, and grade 3 or 4 toxicity event was no difference between 2 regimens.

CONCLUSIONS

Combination of intraoperative intraportal chemotherapy with mFOLFOX6 reduced the occurrence of distant metastases and improved disease-free survival in patients with stage II and stage III colon cancer.

Role of Adjuvant Chemotherapy in ypT0-2N0 Patients Treated with Preoperative Chemoradiation Therapy and Radical Resection for Rectal Cancer

OBJECTIVE

To explore the role of adjuvant chemotherapy for patients with ypT0-2N0 rectal cancer treated by preoperative chemoradiation therapy (PCRT) and radical resection.

PATIENTS AND METHODS

A national consortium of 10 institutions was formed, and patients with ypT0-2N0 mid- and low-rectal cancer after PCRT and radical resection from 2004 to 2009 were included. Patients were categorized into 2 groups according to receipt of additional adjuvant chemotherapy: Adj CTx (+) versus Adj CTx (-). Propensity scores were calculated and used to perform matched and adjusted analyses comparing relapse-free survival (RFS) between treatment groups while controlling for potential confounding.

RESULTS

A total of 1016 patients, who met the selection criteria, were evaluated. Of these, 106 (10.4%) did not receive adjuvant chemotherapy. There was no overall improvement in 5-year RFS as a result of adjuvant chemotherapy [91.6% for Adj CTx (+) vs 87.5% for Adj CTx (-), P=.18]. There were no differences in 5-year local recurrence and distant metastasis rate between the 2 groups. In patients who show moderate, minimal, or no regression in tumor regression grade, however, possible association of adjuvant chemotherapy with RFS would be considered (hazard ratio 0.35; 95% confidence interval 0.14-0.88; P=.03). Cox regression analysis after propensity score matching failed to show that addition of adjuvant chemotherapy was associated with improved RFS (hazard ratio 0.81; 95% confidence interval 0.39-1.70; P=.58).

CONCLUSIONS

Adjuvant chemotherapy seemed to not influence the RFS of patients with ypT0-2N0 rectal cancer after PCRT followed by radical resection. Thus, the addition of adjuvant chemotherapy needs to be weighed against its oncologic benefits.

EMVI-positive stage II rectal cancer has similar clinical outcomes as stage III disease following pre-operative chemoradiotherapy

BACKGROUND

Stage II rectal cancers comprise a heterogeneous group, and there is significant variability in practise with regards to adjuvant chemotherapy; the survival benefit of chemotherapy is perceived to be <4% in these patients. However, in recent years, the emergence of additional prognostic factors such as extramural venous invasion (EMVI) suggests that there may be sub-stratification of stage II tumours and, further, we may be under-estimating the benefit adjuvant chemotherapy provides in high-risk patients. This study examined the outcomes of patients with stage II and III rectal cancer to determine whether EMVI status influences disease-free survival (DFS).

PATIENTS AND METHODS

An analysis of a prospectively maintained database was conducted of patients presenting with rectal cancer between 2006 and 2012. All patients underwent curative surgery and had no evidence of metastases at presentation. Clinicopathological factors were compared between stage II and III disease. The primary end point was 3-year DFS; univariate and multivariate analysis was carried out using Cox proportional hazards regression models; hazard ratios (HR) with 95% confidence intervals (CIs) were calculated.

RESULTS

Four hundred and seventy-eight patients were included: 233 stage II; 245 stage III. The prevalence of EMVI was 34.9%; 57 stage II patients (24.5%) and 110 stage III patients (44.9%). On multivariate analysis, only EMVI status was a significant factor for DFS. The adjusted HR for EMVI either alone or in combination with nodal involvement was 2.08 (95% CI 1.10-2.95) and 2.74 (95% CI 1.66-4.52), respectively.

CONCLUSION

EMVI is an independently poor prognostic factor for DFS for both stage II and stage III rectal cancer. These results demonstrate that there is risk-stratification within stage II tumours which affects prognosis. When discussing the use of adjuvant chemotherapy with patients that have EMVI-positive stage II tumours, these results provide evidence for a similarly increased risk of distant failure as stage III disease without venous invasion.

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

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

Does adjuvant fluoropyrimidine-based chemotherapy provide a benefit for patients with resected rectal cancer who have already received neoadjuvant radiochemotherapy? A systematic review of randomised trials

BACKGROUND

The results of the recently published large European randomised study in rectal cancer (European Organisation for Research and Treatment of Cancer 22921 trial) do not support current guidelines recommending postoperative chemotherapy for patients who have previously undergone preoperative radiochemotherapy or radiotherapy [radio(chemo)therapy]. To evaluate this discrepancy further, a systematic review of relevant randomised trials was undertaken.

MATERIALS AND METHODS

A systematic literature search was carried out in order to identify randomised studies exploring adjuvant chemotherapy against observation in patients with rectal cancer previously treated with preoperative radio(chemo)therapy.

RESULTS

A statistically significant benefit of adjuvant chemotherapy was not found in any of the four relevant randomised trials. Non-protocolised subgroup analysis of one study indicated a beneficial effect of adjuvant chemotherapy for high rectal tumours and for patients downstaged to ypT0-2N0 but no effect for low-lying rectal tumours. However, the body of evidence indicates that patients downstaged after radio(chemo)therapy to ypT0-2N0 disease are not candidates for testing adjuvant chemotherapy in future trials due to the considerable over-treatment anticipated by this manoeuvre.

CONCLUSIONS

To resolve the issue in question, a meta-analysis of relevant studies is required, and new trials should be launched to explore new drug combinations against observation. Currently, delivery of adjuvant chemotherapy in patients undergoing preoperative radio(chemo)therapy is not evidence based.

No socioeconomic inequalities in colorectal cancer survival within a randomised clinical trial

There is strong evidence that colorectal cancer survival differs between socioeconomic groups. We analysed data on 2481 patients diagnosed during 1989-1997 and recruited to a randomised controlled clinical trial (AXIS, ISRCTN32414363) of chemotherapy and radiotherapy for colorectal cancer. Crude and relative survival at 1 and 5 years was estimated in five categories of socioeconomic deprivation. Multiple imputation was used to account for missing data on tumour stage. A multivariable fractional polynomial model was fitted to estimate the excess hazard of death in each deprivation category, adjusting for the confounding effects of age, stage, cancer site (colon, rectum) and sex, using generalised linear models. Relative survival in the trial patients was higher than in the general population of England and Wales. The socioeconomic gradient in survival was much smaller than that seen for colorectal cancer patients in the general population, both at 1 year -3.2% (95% CI -7.3 to 1.0%, P=0.14) and at 5 years -1.7% (95% CI -8.3 to 4.9%, P=0.61). Given equal treatment, colorectal cancer survival in England and Wales does not appear to depend on socioeconomic status, suggesting that the socioeconomic gradient in survival in the general population could well be due to health-care system factors.

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.

Pre-operative radiotherapy and curative surgery for the management of localized rectal carcinoma

BACKGROUND

Preoperative radiotherapy (PRT) has become part of standard practice offered to improve treatment outcomes in patients with rectal cancer.

OBJECTIVES

To determine if PRT improves outcome for patients with localized resectable rectal cancer and how it compared with other adjuvant or neoadjuvant strategies.

SEARCH STRATEGY

A computerized search was performed December 2006 on MEDLINE (from 1966 to December 2006) and the Cochrane Central Register of Controlled Trials (CENTRAL), conference proceedings, using MeSH and textwords where appropriate to identify randomized trials in PRT and rectal cancer. In addition, MetaRegister of Clinical Trials was searched for ongoing trials.

SELECTION CRITERIA

Randomized trials with a PRT arm versus surgery alone, or other neoadjuvant or adjuvant (NA/A) strategies, targeted patients with localized rectal cancer planned for radical surgery were included.

DATA COLLECTION AND ANALYSIS

Trials were selected, data extracted and quality assessed by 2 authors. Quality was assessed using a 14 point checklist. Summary statistics included Hazard ratios and variances (for the outcomes: overall (OA) mortality, cause specific (CS) mortality, any recurrence and local recurrences (LR)) and Odds Ratio (OR) for other outcomes. Potential sources of heterogeneity hypothesized a priori included study quality, biological effective dose (BED), radiotherapy RT technique, and total mesorectal excision (TME) surgery.

MAIN RESULTS

Nineteen trials compared PRT versus surgery alone. Overall (OA) mortality was marginally improved HR 0.93 [95% CI -0.87-1](absolute difference is 2% if the expected survival rate is 60%). Local recurrence (LR) was improved but the magnitude of benefit was heterogeneous across trials. Sensitivity analyses suggested greater benefits in patients treated with BED>30Gy(10) and multiple field RT techniques. There was significantly more pelvic or perineal wound infection, late rectal and sexual dysfunction. Nine trials compared PRT vs. other NA/A. Available evidence did not support an OA mortality or sphincter preserving benefit with the use of combined chemoradiotherapy (CRT) or selective postoperative RT. CRT provides incremental benefit for local control compared with PRT, which was independent of the timing of the CT. There was no significant difference in outcome for different intervals between RT and surgery (2 vs. 8 wk). Dose escalation with endocavitary boost showed significant effect on sphincter preservation.

AUTHORS' CONCLUSIONS

Optimal PRT improves LR, OA mortality, but no increase in sphincter sparing procedure. CRT further increases local control. If the objective is to increase the incidence of sphincter sparing surgery, endocavitary boost showed the most promise. Strategies with the potential to improve outcomes, especially OAS and sphincter sparing while reducing acute and late toxicities (rectal and sexual function) are needed to guide future strategy designs.

Preoperative radiotherapy with or without concurrent fluorouracil and leucovorin in T3-4 rectal cancers: results of FFCD 9203

PURPOSE

In 1992, preoperative radiotherapy was considered in France as the standard treatment for T3-4 rectal cancers. The present randomized trial compares preoperative radiotherapy with chemoradiotherapy.

PATIENTS AND METHODS

Patients were eligible if they presented a resectable T3-4, Nx, M0 rectal adenocarcinoma accessible to digital rectal examination. Preoperative radiotherapy with 45 Gy in 25 fractions during 5 weeks was delivered. Concurrent chemotherapy with fluorouracil 350 mg/m2/d during 5 days, together with leucovorin, was administered during the first and fifth week in the experimental arm. Surgery was planned 3 to 10 weeks after the end of radiotherapy. All patients should receive adjuvant chemotherapy with the same fluorouracil/leucovorin regimen. The primary end point of the trial was overall survival.

RESULTS

A total of 733 patients were eligible. Grade 3 or 4 acute toxicity was more frequent with chemoradiotherapy (14.6% v 2.7%; P < .05). There was no difference in sphincter preservation. Complete sterilization of the operative specimen was more frequent with chemoradiotherapy (11.4% v 3.6%; P < .05). The 5-year incidence of local recurrence was lower with chemoradiotherapy (8.1% v 16.5%; P < .05). Overall 5-year survival in the two groups did not differ.

CONCLUSION

Preoperative chemoradiotherapy despite a moderate increase in acute toxicity and no impact on overall survival significantly improves local control and is recommended for T3-4, N0-2, M0 adenocarcinoma of the middle and distal rectum.

Role of radiotherapy with surgery for T3 and resectable T4 rectal cancer: evidence from randomized trials

PURPOSE

The main treatment for resectable rectal cancer T2-T4 N0-N2 M0 is surgery. The benefit of preoperative or postoperative radiation therapy can be analyzed in terms of improvement of local control, sphincter preservation, and survival weighted against increased toxicity.

METHODS

Only randomized trials can provide strong evidence of a positive cost-benefit ratio of such combined approach. The most recent trials were reviewed.

RESULTS

Three randomized trials, including the latest German CAO-ARO trial, have demonstrated the superiority of preoperative radiotherapy with or without chemotherapy (vs. postoperative) in terms of local control and toxicity. The Ducth TME trial showed that even with modern standard surgery, preoperative radiotherapy improved local control. Preoperative irradiation using a high dose in a small volume and a long interval before surgery may improve sphincter preservation (Lyon trials). Concurrent chemoradiation (FFCD 9203, EORTC 22921, did not significantly improve sphincter preservation or survival but significantly reduced the local recurrence rate.

CONCLUSIONS

In 2005 examination of randomized trials provides evidence for the benefit of preoperative chemoradiation in improving local control and probably sphincter preservation in rectal cancer. Randomized trials should be designed to further demonstrate improved sphincter preservation and to increase survival using adjuvant medical treatments.

Chemotherapy for colorectal cancer--an overview of current management for surgeons

BACKGROUND

The role of systemic chemotherapy in the management of colorectal cancer has been re-evaluated with the advent of newer agents. The results of published trials are reviewed in this article and the protocols of some of the major ongoing trials outlined.

METHODS

A medline based literature search was performed for articles relating to clinical trials using systemic chemotherapy in the management of colorectal cancer in the advanced and adjuvant setting. Additional original papers were obtained from citations in those identified by the initial search.

RESULTS

The combination of irinotecan or oxaliplatin with 5-fluorouracil (5-FU) based chemotherapy regimens for advanced cancer demonstrates better response rates when compared with 5-FU and folinic acid (FA). Although this translates into a modest survival benefit, it may increase resectability rates in patients with hepatic metastasis. Adjuvant chemotherapy in stage III cancer has been established to improve long-term survival although it is benefit for patients with stage II disease remains less clear.

CONCLUSION

Evaluation of the various combinations of chemotherapeutic agents that are most effective and the clinical situations for which they are best suited is ongoing and will improve the current outlook for those with colorectal cancer.

Radiotherapy in the conservative treatment of rectal cancer. Evidence-based medicine and opinion

BACKGROUND AND PURPOSE

This lecture is given on behalf of my former Lyon Sud Radiotherapy department (Dr P. Romestaing) and of the Radiotherapy Department of Centre Antoine-Lacassagne in Nice (Dr A. Courdi) without which it would have been impossible to produce any original clinical data. The major benefit from radiotherapy (RXT) in oncology can be summarized with 3 'C': cure-cost effectiveness-conservative treatment.

PATIENTS AND METHODS

Rectal cancer illustrates the hypothesis that radiotherapy can increase the chance of conservative treatment (with sphincter preservation SP). Sphincter preservation is a complex process, and only randomized trials can be used to see if preoperative treatment can increase SP.

RESULTS

Different phase III trials have shown that: preoperative RXT is superior to postop RX (local control--toxicity--SP), preoperative RXT with immediate surgery does not increase SP, preoperative RXT with delayed surgery increases SP, concurrent chemotherapy with RXT has not yet proven to increase SP, important dose escalation (90 Gy) with contact X-ray RXT increases complete clinical tumor response and SP.

CONCLUSIONS

The surgeon is the key person for the cure of rectal cancer and mainly responsible for the decision of sphincter preservation. The experience gained with contact X-ray therapy stresses the importance of a complete clinical tumor response before surgery to increase the chance of sphincter preservation. 'High dose small volume' RXT is a key factor to achieve such a complete clinical tumor response.

Recent randomised trials in colorectal disease

Randomised trials represent the 'gold standard' for surgical research and have an important impact on clinical management. We provide an overview of the randomised trials, specifically related to the practice of colorectal surgery that were published between January and December 2003.

Colon cancer: survival after curative surgery

Several new aspects have evolved during the past years concerning factors that influence survival in surgically and medically treated colon cancer patients that are relevant to the treating team for the treatment strategy and patient's choice. The 5-year-survival rates dependent on UICC stages/substages (I: 68%-100%, II: 58%-90%, III: 33%-76%, IV: <5%-9%) show remarkable variations between published reports, surgical hospital units, individual surgeons, and continents (USA vs Europe). Those variations may be due to surgical techniques, training status, hospital and individual case volume, and, also, referral patterns and statistical evaluation methods. Survival times and cure rates are significantly improved by adjuvant chemotherapy in UICC III and in substages of UICC II (e.g. UICC II B) by 5%-12%, when compared with surgical controls. In three recently published trials standard adjuvant chemotherapy was further improved by increased survival rates, e.g. from 59% to 71% in stage III and IIB patients. Molecular and genetic factors, such as thymidylate synthase (TS), microsatellite instability (MSI) or loss of chromosome 18q/"DCC" might have an independent impact on prognosis in the spontaneous course, and TS could help to better select patients for adjuvant chemotherapy.