Postoperative adjuvant chemotherapy with mitomycin C and UFT for curatively resected rectal cancer. Results from the Cooperative Project No.7 Group of the Japanese Foundation for Multidisciplinary Treatment of Cancer

Systematic Review: Adjuvant Chemotherapy for Locally Advanced Rectal Cancer with respect to Stage of Disease

Background. Recent meta-analysis of 21 randomised controlled trials (RCTs) supports the use of adjuvant chemotherapy for nonmetastatic rectal carcinoma. In order to define a subgroup of patients who can potentially benefit from postoperative adjuvant chemotherapy, this study aims to review trials investigating adjuvant chemotherapy with respect to stage of disease in patients with locally advanced rectal cancer who had undergone surgery for cure (stage II and stage III). Methods. We searched electronic information sources to identify randomised trials evaluating adjuvant chemotherapy in patients with stages II and III rectal cancer with overall survival or disease-free survival as outcomes. Scottish Intercollegiate Guidelines Network notes on methodology were used to assess the methodological quality of the selected studies. Random-effects models were applied to calculate pooled outcome data. Results. Eight studies reporting total of 5527 patients were selected for analysis. Adjuvant chemotherapy was associated with statistically significant improvement in disease-free survival and overall survival compared to surgery alone in both stage II and stage III cancer. Conclusions. This study indicates that both stage II and stage III rectal cancer patients may benefit from postoperative adjuvant chemotherapy. However, the benefits of adjuvant chemotherapy for patients who already had neoadjuvant chemoradiation still remain unknown.

Postoperative adjuvant chemotherapy in rectal cancer operated for cure

BACKGROUND

Colorectal cancer is one of the most common types of cancer in the Western world. Apart from surgery - which remains the mainstay of treatment for resectable primary tumours - postoperative (i.e., adjuvant) chemotherapy with 5-fluorouracil (5-FU) based regimens is now the standard treatment in Dukes' C (TNM stage III) colon tumours i.e. tumours with metastases in the regional lymph nodes but no distant metastases. In contrast, the evidence for recommendations of adjuvant therapy in rectal cancer is sparse. In Europe it is generally acknowledged that locally advanced rectal tumours receive preoperative (i.e., neoadjuvant) downstaging by radiotherapy (or chemoradiotion), whereas in the US postoperative chemoradiotion is considered the treatment of choice in all Dukes' C rectal cancers. Overall, no universal consensus exists on the adjuvant treatment of surgically resectable rectal carcinoma; moreover, no formal systematic review and meta-analysis has been so far performed on this subject.

OBJECTIVES

We undertook a systematic review of the scientific literature from 1975 until March 2011 in order to quantitatively summarize the available evidence regarding the impact of postoperative adjuvant chemotherapy on the survival of patients with surgically resectable rectal cancer. The outcomes of interest were overall survival (OS) and disease-free survival (DFS).

SEARCH METHODS

CCCG standard search strategy in defined databases with the following supplementary search. 1. Rect* or colorect* - 2. Cancer or carcinom* or adenocarc* or neoplasm* or tumour - 3. Adjuv* - 4. Chemother* - 5. Postoper*

SELECTION CRITERIA

Randomised controlled trials (RCT) comparing patients undergoing surgery for rectal cancer who received no adjuvant chemotherapy with those receiving any postoperative chemotherapy regimen.

DATA COLLECTION AND ANALYSIS

Two authors extracted data and a third author performed an independent search for verification. The main outcome measure was the hazard ratio (HR) between the risk of event between the treatment arm (adjuvant chemotherapy) and the control arm (no adjuvant chemotherapy). The survival data were either entered directly in RevMan or extrapolated from Kaplan-Meier plots and then entered in RevMan. Due to expected clinical heterogeneity a random effects model was used for creating the pooled estimates of treatment efficacy.

MAIN RESULTS

A total of 21 eligible RCTs were identified and used for meta-analysis purposes. Overall, 16,215 patients with colorectal cancer were enrolled, 9,785 being affected with rectal carcinoma. Considering patients with rectal cancer only, 4,854 cases were randomized to receive potentially curative surgery of the primary tumour plus adjuvant chemotherapy and 4,367 to receive surgery plus observation. The mean number of patients enrolled was 466 (range: 54-1,243 cases). 11 RCTs had been performed in Western countries and 10 in Japan. All trials used fluoropyrimidine-based chemotherapy (no modern drugs - such as oxaliplatin, irinotecan or biological agents - were tested).Overall survival (OS) data were available in 21 RCTs and the data available for meta-analysis regarded 9,221 patients: of these, 4854 patients were randomized to adjuvant chemotherapy (treatment arm) and 4,367 patients did not receive adjuvant chemotherapy (control arm). The meta-analysis of these RCTs showed a significant reduction in the risk of death (17%) among patients undergoing postoperative chemotherapy as compared to those undergoing observation (HR=0.83, CI: 0.76-0.91). Between-study heterogeneity was moderate (I-squared=30%) but significant (P=0.09) at the 10% alpha level.Disease-free survival (DFS) data were reported in 20 RCTs, and the data suitable for meta-analysis included 8,530 patients. Of these, 4,515 patients were randomized to postoperative chemotherapy (treatment arm) and 4,015 patients received no postoperative chemotherapy (control arm). The meta-analysis of these RCTs showed a reduction in the risk of disease recurrence (25%) among patients undergoing adjuvant chemotherapy as compared to those undergoing observation (HR=0.75, CI: 0.68-0.83). Between-study heterogeneity was moderate (I-squared=41%) but significant (P=0.03).While analyzing both OS and DFS data, sensitivity analyses did not find any difference in treatment effect based on trial sample size or geographical region (Western vs Japanese). Available data were insufficient to investigate on the effect of adjuvant chemotherapy separately in different TNM stages in terms of both OS and DFS. No plausible source of heterogeneity was formally identified, although variability in treatment regimens and TNM stages of enrolled patients might have played a significant role in the difference of reported results.

AUTHORS' CONCLUSIONS

The results of this meta-analysis support the use of 5-FU based postoperative adjuvant chemotherapy for patients undergoing apparently radical surgery for non-metastatic rectal carcinoma. Available data do not allow us to define whether the efficacy of this treatment is highest in one specific TNM stage. The implementation of modern anti-cancer agents in the adjuvant setting is warranted to improve the results shown by this meta-analysis. Randomized trials of adjuvant chemotherapy for patients receiving preoperative neoadjuvant therapy are also needed in order to define the role of postoperative chemotherapy in the multimodal treatment of resectable rectal cancer.

High-risk stage II colon cancer after curative resection

OBJECTIVES

This study was designed to clarify which attributes of stage II colon cancer are associated with tumor recurrence and survival after curative resection, and the effects of adjuvant chemotherapy (ACT).

METHODS

We retrospectively reviewed outcomes and clinicopathological characteristics of 1476 patients with stage II colon cancer who underwent curative resection.

RESULTS

Of 1476 patients, 204 (13.8%) developed recurrence. Macroscopic type, serum CA19-9 levels, venous invasion, emergency operation, and postoperative ileus were independently associated with overall recurrence. Carbohydrate antigen (CA)19-9 levels, the number of dissected lymph nodes (LN), sex, age, ACT, emergency operation, venous invasion, and macroscopic type were independently associated with poor prognosis. Prognosis was significantly better in patients who received ACT than in those who did not. Among patients with extensive venous invasion, those with fewer than 13 dissected LNs, male patients, and patients >50 years old, the prognosis was significantly better in patients who received ACT than in those who did not.

CONCLUSIONS

ACT for stage II colon cancer is recommended to improve the prognosis of patients with extensive venous invasion, patients with fewer than 13 dissected LNs, patients >50 years old, and male patients, particularly patients with more than two of these risk factors.

Histological bioanalysis for therapeutic effects of hybrid liposomes on the hepatic metastasis of colon carcinoma in vivo

Therapeutic effects of hybrid liposomes (HL) composed of l-alpha-dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene (23) dodecylether (C(12)(EO)(23)) on the metastasis of colon carcinoma (Colon26) cells were examined in vivo. Fluorescent labeled Colon26 cells were observed in the liver tissue of hepatic metastasis mouse models after the intrasplenic inoculation of the cells. Remarkably high therapeutic effects were obtained in the hepatic metastasis mouse models after the treatment with HL on the basis of relative liver weight and histological analysis of the liver tissue sections of mouse models with hematoxylin-eosin staining, Masson trichrome staining, and CEA immunostaining as a histochemical marker of metastatic colon carcinoma. Furthermore, no toxicity was observed in the hepatic metastasis mouse models after the intravenous injection of HL. Therapeutic effects of HL without any drugs on the hepatic metastasis were revealed on the basis of histological analysis for the first time in vivo.

[Marked therapeutic effects of hybrid liposomes on the hepatic metastasis of colon carcinoma]

Hybrid liposomes (HLs) composed of vesicular and micellar surfactants have inhibitory effects on the growth of tumor cells in vitro and in vivo. Successful clinical chemotherapy with drug-free HLs to patient with lymphoma has been reported after approval by the Committe of Bioethics. However, the therapeutic effects of HLs on the metastasis of colon carcinoma cells have not yet been elucidated. In this study, the therapeutic effects of HLs composed of L-alpha-dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene (23) dodecyl ether [C(12)(EO)(23)] on the metastasis of colon carcinoma (Colon26) cells were examined in vivo. Marked high therapeutic effects were obtained in the hepatic metastasis mice model after the treatment with HLs. Furthermore, optical microscopic analysis indicated that HLs could induce the apoptosis of colon carcinoma cells in vivo. No toxicity was observed in the hepatic metastasis mice model after intravenously injecting HLs. Therapeutic effects along with the induction of apoptosis by HLs without any drugs on hepatic metastasis were revealed on the basis of optical microscopic analysis for the first time in vivo.

The role of meta-analysis in cancer clinical trials

Meta-analysis of randomized controlled trials is considered to be the methodology that provides the most solid scientific basis for constructing clinical guidelines. It involves systematically collecting the results of similar studies that were conducted to verify similar medical hypotheses and combining these results statistically. In meta-analysis, targeting only those randomized controlled trials with good comparability also provides the meta-analysis with comparability. With the combining of multiple studies and the increased sample size, meta-analysis provides results with higher clarity than those obtained from a single study. In conventional meta-analyses, in addition to estimating the combined effect, the cause of heterogeneity of the effects among studies is usually explored. If multiple studies reveal homogeneous effects, the overall effect is interpretable and generalizability can be suggested; that is, the results can be reproducible even when the study conditions are slightly modified. On the other hand, if the effect cannot be viewed as homogeneous among the studies, it is difficult to interpret the overall effect obtained from a meta-analysis. From the viewpoints of clarity, comparability, and generalizability, meta-analysis and large-scale clinical trials can provide the most valuable evidence among several possible study designs. In this article, the role of meta-analysis in cancer clinical trials is illustrated with the example of adjuvant therapy with UFT in patients with curatively resected rectal cancer, compared with the example of a large-scale clinical trial using oxaliplatin, fluorouracil, and leucovorin as adjuvant treatment for colon cancer.

Cost-effectiveness of adjuvant chemotherapy with uracil-tegafur for curatively resected stage III rectal cancer

Recently, the National Surgical Adjuvant Study of Colorectal Cancer in Japan, a randomised controlled trial of oral uracil-tegafur (UFT) adjuvant therapy for stage III rectal cancer, showed remarkable survival gains, compared with surgery alone. To evaluate value for money of adjuvant UFT therapy, cost-effective analysis was carried out. Cost-effectiveness analysis of adjuvant UFT therapy was carried out from a payer's perspective, compared with surgery alone. Overall survival and relapse-free survival were estimated by Kaplan-Meier method, up to 5.6 years from randomisation. Costs were estimated from trial data during observation. Quality-adjusted life-years (QALYs) were calculated using utility score from literature. Beyond observation period, they were simulated by the Boag model combined with the competing risk model. For 5.6-year observation, 10-year follow-up and over lifetime, adjuvant UFT therapy gained 0.50, 0.96 and 2.28 QALYs, and reduced costs by $2457, $1771 and $1843 per person compared with surgery alone, respectively (3% discount rate for both effect and costs). Cost-effectiveness acceptability and net monetary benefit analyses showed the robustness of these results. Economic evaluation of adjuvant UFT therapy showed that this therapy is cost saving and can be considered as a cost-effective treatment universally accepted for wide use in Japan.

An individual patient data meta-analysis of adjuvant therapy with uracil-tegafur (UFT) in patients with curatively resected rectal cancer

Uracil–Tegafur (UFT), an oral fluorinated pyrimidine chemotherapeutic agent, has been used for adjuvant chemotherapy in curatively resected colorectal cancer patients. Past trials and meta-analyses indicate that it is somewhat effective in extending survival of patients with rectal cancer. The objective of this study was to perform a reappraisal of randomised clinical trials conducted in this field. We designed an individual patient-based meta-analysis of relevant clinical trials to examine the benefit of UFT for curatively resected rectal cancer in terms of overall survival (OS), disease-free survival (DFS), and local relapse-free survival (LRFS). We analysed individual patient data of five adjuvant therapy randomised clinical trials for rectal cancer, which met the predetermined inclusion criteria. These five trials had a combined total of 2091 patients, UFT as adjuvant chemotherapy compared to surgery-alone, 5-year follow-up, intention-to-treat-based analytic strategy, and similar endpoints (OS and DFS). In a pooled analysis, UFT had significant advantage over surgery-alone in terms of both OS (hazard ratio, 0.82; 95% confidence interval (CI), 0.70–0.97; P=0.02) and DFS (hazard ratio, 0.73; 95%CI, 0.63–0.84; P<0.0001). This individual patient-based meta-analysis demonstrated that oral UFT significantly improves both OS and DFS in patients with curatively resected rectal cancer.

Adjuvant Chemotherapy with Uracil–Tegafur for Pathological Stage III Rectal Cancer after Mesorectal Excision with Selective Lateral Pelvic Lymphadenectomy: A Multicenter Randomized Controlled Trial*

BACKGROUND

Although adjuvant radiotherapy was proved to be effective for local control of rectal cancer even after standardized mesorectal excision, the role of adjuvant chemotherapy after such standardized surgery remains to be clarified. We aimed to assess the efficacy of a combination of uracil and tegafur for pathological stage III rectal cancer treated by standardized mesorectal excision with selective lateral pelvic lymphadenectomy.

METHODS

We randomly assigned patients with completely resected stage III rectal cancer, who underwent standardized mesorectal excision with selective lateral pelvic lymphadenectomy, to receive either oral uracil-tegafur (400 mg/m2 tegafur per day) for one year or no treatment. Standardization and quality control of the surgery and pathological techniques were ensured by use of the guidelines of the Japanese Society for Cancer of the Colon and Rectum. The primary endpoint was relapse-free survival. The secondary endpoint was overall survival.

RESULTS

We enrolled and randomized 276 patients. Excluding two ineligible patients, 274 were included in the analysis. Planned interim analysis 2 years after accrual termination revealed significant prolongation of relapse-free survival (P = 0.001) and overall survival (P = 0.005) in the uracil-tegafur group. The 3-year relapse-free survival and overall survival rates were 78 and 91% in the chemotherapy group and 60 and 81% in the surgery-alone group, respectively. Local recurrence rates were low in both groups. Grade 3 events occurred in 17% of the chemotherapy patients, but no grade 4 or more events occurred.

CONCLUSION

Adjuvant chemotherapy with uracil-tegafur improves survival of patients with stage III rectal cancer after standardized mesorectal excision with selective lateral pelvic lymphadenectomy.

Efficacy of Oral Adjuvant Therapy After Resection of Colorectal Cancer: 5-Year Results From Three Randomized Trials

Purpose

Adjuvant therapy of colorectal cancer with oral fluorinated pyrimidines is attractive because of its ease of administration and good tolerability. The purpose of this meta-analysis is to assess the survival and disease-free survival benefits of treating patients after surgical resection of a primary colorectal tumor with oral fluoropyrimidines for 1 year.

Patients and Methods

This meta-analysis was performed on individual data from three randomized trials conducted by the Japanese Foundation for Multidisciplinary Treatment for Cancer involving a total of 5,233 patients with stages I to III colorectal cancer.

Results

The overall hazard ratio in favor of oral therapy was 0.89 for survival (95% CI, 0.80 to 0.99; P = .04), and 0.85 for disease-free survival (95% CI, 0.77 to 0.93; P < .001). Thus oral therapy reduced the risk of death by 11% and the risk of recurrence or death by 15%. There was no significant heterogeneity between trials, nor did the benefit of oral therapy depend on tumor stage (I, II, or III), tumor site (rectum or colon), patient age, or patient sex.

Conclusion

Oral fluoropyrimidines improve disease-free survival and survival of patients after resection of early-stage colorectal cancer. These observations support the use of these agents alone after resection of early-stage disease, as well as further testing of oral agents in combination with new drugs that have recently shown antitumor activity in advanced colorectal cancer.

Comparative detection of lymph node micrometastases of stage II colorectal cancer by reverse transcriptase polymerase chain reaction and immunohistochemistry

PURPOSE

Inconsistent conclusions have been drawn about the clinical significance of micrometastases in lymph nodes (LNs) of node-negative colorectal cancer (CRC) patients. We performed a comparative study of detection of micrometastases using immunohistochemistry (IHC) by anti-cytokeratin antibody and carcinoembryonic antigen (CEA)-specific reverse-transcriptase polymerase chain reaction (RT-PCR) in the same patients, in an attempt to move closer to their clinical application.

PATIENTS AND METHODS

Sixty-four CRC patients, with RNA of good quality available from paraffin-embedded LN specimens, were selected from 84 stage II patients who underwent curative surgery between 1988 and 1996. We investigated associations between the presence of micrometastases by each method and prognosis.

RESULTS

Micrometastases were detected in 19 (29.6%) of 64 patients by RT-PCR and in 35 (54.7%) of 64 patients by IHC. By RT-PCR analysis, patients exhibiting a positive band for CEA mRNA had a significantly worse prognosis than those who were RT-PCR-negative, with respect to both disease-free and overall survival (P =.027 and.015, respectively). By IHC analysis, the presence of micrometastasis did not predict patient outcome in terms of either disease-free or overall survival. Infiltrating pattern of tumor growth characteristic was significantly associated with shorter disease-free survival among various clinical or pathologic factors. By multivariate Cox regression analysis, micrometastasis detected by RT-PCR and the Crohn's-like lymphoid reaction were both independent prognostic factors.

CONCLUSION

Micrometastases detected by RT-PCR, but not IHC, may be of clinical value in identifying patients who may be at high risk for recurrence of CRC and who are therefore likely to benefit from systemic adjuvant therapy.

Oral tegafur/uracil

Tegafur is a prodrug of the antineoplastic agent fluorouracil, and is administered in a 1:4 molar ratio with the fluorouracil modulator uracil. Oral tegafur/uracil 300 mg/m(2)/day plus calcium folinate 75 or 90 mg/day for 28 days every 35 days was as effective as intravenous (IV) fluorouracil 425 mg/m(2)/day plus folinic acid 20 mg/m(2)/day for 5 days every 28 or 35 days in the treatment of patients with metastatic colorectal cancer in two large, randomised, nonblind, multicentre trials (n = 816 and 380). Median survival time among patients treated with tegafur/ uracil or fluorouracil was approximately 12 months in both trials. Results from both trials also demonstrated no significant between-group differences in overall response rates among patients treated with oral tegafur/uracil (12 and 11%) or IV fluorouracil (15 and 9%). In elderly patients (aged > or = 70 years) with metastatic colorectal cancer, results from small noncomparative studies showed that treatment with oral tegafur/uracil afforded overall response rates of 12.5 to 29% and was well tolerated. During preoperative treatment with oral tegafur/uracil plus calcium folinate as an adjunct to radiotherapy in patients with stage II or III rectal cancer, the maximum tolerated dosage of tegafur/uracil was 350 mg/m(2)/day (administered 5 days per week for 5 weeks). Among the 15 patients who were followed for 5 to 8 months, three had a complete response to treatment. Treatment with tegafur/uracil was also given postoperatively. The most common adverse events associated with oral tegafur/uracil were anaemia, nausea/vomiting, diarrhoea, thrombocytopenia, mucositis, neutropenia, asthenia, anorexia and abdominal pain. Oral tegafur/uracil was associated with a significantly more favourable tolerability profile than IV fluorouracil in the two large randomised trials. In particular, stomatitis and most adverse haematological events were less frequent.