Folinic acid and 5-fluorouracil as adjuvant chemotherapy in colon cancer

Identifying patients with T3-T4 node-negative colon cancer at high risk of recurrence

PURPOSE

Adjuvant chemotherapy is effective for node-positive colon cancer patients. In node-negative patients, it could be justified in high-risk patients. The purpose of this study was to determine clinical and pathological findings associated with tumor recurrence in T3-T4 node-negative colon cancer patients.

METHODS

From 1974 to 1993, 108 patients undergoing colectomy for T3-4N0M0 colon cancer, without adjuvant chemotherapy, followed until death or for a minimum of five years, were divided into two groups: patients without recurrence (n = 74) and those dead from colon cancer or alive with recurrence (n = 34). Thirty-three clinical and pathological findings were studied.

RESULTS

In univariate analysis, the following were significantly associated with a high risk of tumor recurrence: male patients (P = 0.006), bowel obstruction (P < 0.001), weight loss >5 Kg (P = 0.03), circumferential tumor (P = 0.02), macroscopic or microscopic pericolic organ invasion (T4 stage; P < 0.001), perineural invasion (P = 0.02), vascular invasion (P = 0.045), poor tumor differentiation (P = 0.005), mesocolic invasion >1 cm (P = 0.009), less than 14 uninvolved nodes on the specimen (P = 0.03), and visceral peritoneal invasion (T4; P < 0.001). In multivariate analysis, the following were independent prognostic factors of recurrence: male patients (P = 0.005), bowel obstruction (P = 0.002), pericolic organ invasion (i.e., T4 tumor; P = 0.02), and less than 14 uninvolved nodes on a specimen (P = 0.01). On the other hand, preoperative carcinoembryonic antigen serum level, size and tumor location, blood transfusion, and mucin production were not associated with higher risk of tumor recurrence.

CONCLUSION

Our study identifies a subgroup of patients with node-negative colon cancer at high risk of recurrence, who could be included in priority trials of adjuvant chemotherapy.

Adjuvant chemotherapy for colon carcinoma with positive lymph nodes: use and benefit in routine health care practice

In 1990, an international consensus was reached on the efficacy of adjuvant chemotherapy for lymph node positive (stage III) colon carcinoma (CC). This study evaluates the use and benefit of such therapy in routine health care practice. The study includes all patients with stage III CC treated by putative curative surgery (n = 182) recorded at the Geneva cancer registry between 1990 and 1996. Factors modifying chemotherapy use were determined by logistic regression, considering patients with chemotherapy as cases (n = 55) and others as controls (n = 127). The effect of chemotherapy on the 5-year survival was evaluated by the Cox model. Analyses were adjusted for possible confounders. The use of chemotherapy increased over the period (P(trend) < 0.001). Age strongly modulated chemotherapy use. In 1996, 54% of eligible patients received chemotherapy, this proportion fell to 13% after age 70. Decisions to use chemotherapy significantly depended on stage, grade and cancer site. The chance to be treated was non-significantly lower among individuals of low social class, widowed and foreigners. Chemotherapy significantly decreased mortality rates (Hazard ratio: 0.35, 95%CI: 0.18-0.68), independently of the prognostic factors and with similar benefit regardless of stage and age group. Strong beneficial effect of adjuvant chemotherapy on stage III CC can be achieved in routine practice. However, this study shows that it is probably not optimally utilised in Switzerland, particularly among the elderly.

A pooled analysis of adjuvant chemotherapy for resected colon cancer in elderly patients

BACKGROUND

Adjuvant chemotherapy is standard treatment for patients with resected colon cancer who are at high risk for recurrence, but the efficacy and toxicity of such treatment in patients more than 70 years of age are controversial.

METHODS

We performed a pooled analysis, based on the intention to treat, of individual patient data from seven phase 3 randomized trials (involving 3351 patients) in which the effects of postoperative fluorouracil plus leucovorin (five trials) or fluorouracil plus levamisole (two trials) were compared with the effects of surgery alone in patients with stage II or III colon cancer. The patients were grouped into four age categories of equal size, and analyses were repeated with 10-year age ranges (< or =50, 51 to 60, 61 to 70, and >70 years), with the same conclusions. The toxic effects measured in all trials were nausea or vomiting, diarrhea, stomatitis, and leukopenia. Patients in the fluorouracil-plus-leucovorin and fluorouracil-plus-levamisole groups were combined for the efficacy analysis but kept separate for toxicity analyses.

RESULTS

Adjuvant treatment had a significant positive effect on both overall survival and time to tumor recurrence (P<0.001 for each, with hazard ratios of death and recurrence of 0.76 [95 percent confidence interval, 0.68 to 0.85] and 0.68 [95 percent confidence interval, 0.60 to 0.76], respectively). The five-year overall survival was 71 percent for those who received adjuvant therapy, as compared with 64 percent for those untreated. No significant interaction was observed between age and the efficacy of treatment. The incidence of toxic effects was not increased among the elderly (age >70 years), except for leukopenia in one study.

CONCLUSIONS

Selected elderly patients with colon cancer can receive the same benefit from fluorouracil-based adjuvant therapy as their younger counterparts, without a significant increase in toxic effects.

In vitro generation of cytotoxic T lymphocytes against HLA-A2.1-restricted peptides derived from human thymidylate synthase

5-Fluorouracil (5-FU) is a pyrimidine antimetabolite active against colorectal carcinoma and other malignancies of the digestive tract. Over-expression or mutation of thymidylate synthase (TS), the target enzyme of the 5-FU metabolite, 5-fluorodeoxyuridine monophosphate, is strictly correlated with cancer cell resistance to 5-FU. On this basis we investigated whether TS is a potential target for active specific immunotherapy of human colon carcinoma, which acquires resistance to 5-FU. Three TS-derived epitope peptides which fit defined amino acid consensus motifs for HLA-A2.1 binding were synthesized and investigated for their ability to induce human TS-specific cytotoxic T cell (CTL) responses in vitro. CTL lines specific for each peptide were established by stimulating peripheral blood mononuclear cells (PBMC) from an HLA-A2.1+ healthy donor with autologous dendritic cells loaded with TS peptide. Specific CTL lines showed HLA-A2.1-restricted cytotoxicity in vitro to HLA-A2.1+ target cells pulsed with the specific TS peptide and to HLA-class I matching colon carcinoma target cells over-expressing TS enzyme after exposure to 5-FU. Recognition by CTL lines suggests that these TS peptides may be potential candidates for use in a peptide-based vaccine against 5-FU resistant colon carcinoma.

High-risk groups of patients with Stage II colon carcinoma

BACKGROUND

It is unclear whether patients with Stage II colon carcinoma should be offered adjuvant chemotherapy. Therefore, the authors analyzed the risk factors of these patients to identify high-risk subgroups who may benefit from such treatment.

METHODS

The data from 305 patients with Stage II colon carcinoma documented in the Erlangen Registry of Colorectal Carcinoma were analyzed to identify risk factors for distant metastasis and disease-related survival. The patients were divided into two subgroups: those in a low-risk group and those in a high-risk group. The data were then compared with those from 306 patients with Stage II colon carcinoma from the German Study Group for Colorectal Carcinoma (SGCRC).

RESULTS

Emergency presentation, a primary tumor site in the left colon, pT3 tumors with a depth of invasion of > 15 mm beyond the outer border of the muscularis propria, and pT4 lesions were identified as the major risk factors for Stage II colon carcinoma. On dividing patients into subgroups according to these risk factors, it was found that patients in the high-risk group had a significantly higher risk of distant metastases and a significantly lower disease-related survival rate compared with patients in the low-risk group. On analyzing the SGCRC data, the authors also found a significantly higher rate of distant metastases in the high-risk group, but the disease-related survival rate differed only marginally.

CONCLUSIONS

Among patients with Stage II colon carcinoma, it is possible to identify a high-risk group of patients who may be candidates for adjuvant chemotherapy. Stratification by the risk factors emergency presentation, tumor site, depth of tumor invasion, and surgical department should be employed in further clinical studies.

Monthly 5-days 5-fluorouracil and low-dose leucovorin for adjuvant chemotherapy in colon cancer

We investigated the dose-related effect of the 5-fluorouracil (5-FU)/leucovorin regimen on survival in 139 colon cancer patients with Dukes' B2 and C2 stage disease. Chemotherapy consisted of 400 mg/m(2) of 5-FU and 20 mg/m(2) of leucovorin injected daily for 5 days in every 4 weeks for a maximum of 12 cycles. The total dose of 5-FU administered per body surface area had a significant effect on the 5-year disease-free survival and 5-year overall survival in stage B2 and C2 colon cancer patients (P=0.0018, P=0.0011). Analysis with reference to the median DSDI demonstrated that there was a significant difference in 5-year survival in Dukes' C2 (P=0.0016), but survival was not affected by the dose intensity. Multivariate analysis demonstrated that only the total dose of 5-FU administered per surface area affected the 5-year disease-free survival and 5-year overall survival (P=0.0016, P=0.0007, respectively). It can be concluded that the total dose of 5-FU administered is important in planned dosage schedule of adjuvant chemotherapy in colon cancer.

Fluorouracil plus leucovorin as effective adjuvant chemotherapy in curatively resected stage III colon cancer: results of the trial adjCCA-01

PURPOSE

Adjuvant postoperative treatment with fluorouracil (5-FU) and levamisole in curatively resected stage III colon cancer significantly reduces the risk of cancer recurrence and improves survival. Biochemical modulation of 5-FU with leucovorin has resulted in increased remission rates in metastatic colorectal cancer, thus reflecting an increased tumor-cell kill. The impact of 5-FU plus leucovorin on survival and tumor recurrence was analyzed in comparison with the effects of 5-FU plus levamisole in the prospective multicentric trial adjCCA-01.

PATIENTS AND METHODS

Patients with a curatively resected International Union Against Cancer stage III colon cancer were stratified according to T, N, and G category and randomly assigned to receive one of the two adjuvant treatment schemes: 5-FU 400 mg/m(2) body-surface area intravenously in the first chemotherapy course, then 450 mg/m(2) x 5 days; 12 cycles, plus leucovorin 100 mg/m(2) (arm A), or 5-FU plus levamisole (Moertel scheme; arm B).

RESULTS

Six hundred eighty (96.9%) of 702 patients enrolled onto this study were eligible. After a median follow-up time of 46.5 months, the 5-FU plus leucovorin combination significantly improved disease-free survival (P =.037) and significantly decreased overall mortality (P =.0089) in comparison with 5-FU plus levamisole. In a multivariate proportional hazards model, adjuvant chemotherapy emerged as a significant prognostic factor for survival (P =.0059) and disease-free survival (P =.03). Adjuvant treatment with 5-FU plus levamisole as well as with 5-FU plus leucovorin was generally well tolerated; only a minority of patients experienced grade 3 and 4 toxicities.

CONCLUSION

After a curative resection of a stage III colon cancer, adjuvant treatment with 5-FU plus leucovorin is generally well tolerated and significantly more effective than 5-FU plus levamisole in reducing tumor relapse and improving survival.

Should Dukes' B patients receive adjuvant therapy? A statistical perspective

The benefit of adjuvant therapy, such as 5-fluorouracil (5-FU) combined with leucovorin, is a matter of debate for patients with Dukes' B colon cancer. Several approaches have been taken to address this issue. Initially, studies were conducted to assess treatment benefits in both Dukes' B and Dukes' C patients. These studies identified an overall benefit of adjuvant treatment and enrolled enough Dukes' C patients to determine a treatment benefit for adjuvant 5-FU/leucovorin in this subpopulation. However, the individual studies were insufficiently powered to detect a treatment benefit in Dukes' B patients. An analysis of four separate studies (National Surgical Adjuvant Breast and Bowel project) compared the benefit of adjuvant treatment in Dukes' B patients with that in Dukes' C patients and showed similar relative reductions in mortality and disease-free survival in Dukes' B and in Dukes' C patients. The Liver Infusion Meta-Analysis Group also reported similar relative benefits from a portal vein infusion of 5-FU-based chemotherapy in Dukes' B and Dukes' C patients. The International Multicenter Pooled Analysis of Colon Cancer Trials B2 study, which combined data from patients with Dukes' B colon cancer in five separate trials, failed to show a statistically significant benefit of adjuvant 5-FU/leucovorin compared with surgery alone. We review the advantages and limitations of different approaches to detect treatment benefits in patients with Dukes' B colon cancer, and we argue that there is a need for a meta-analysis of all adjuvant trials to reliably address this question.

A United Kingdom coordinating committee on cancer research study of adjuvant chemotherapy for colorectal cancer: preliminary results

Standard adjuvant chemotherapy for colorectal cancer consists of 5-fluorouracil with leucovorin or levamisole. The large, multicenter, randomized, double-blind QUASAR (Quick and Simple and Reliable) trial investigated whether treatment with a higher dose of leucovorin or the addition of levamisole to 5-fluorouracil and leucovorin improved survival. In the QUASAR study, 4,927 patients with colorectal cancer with no evidence of residual disease following resection, were randomized to receive fluorouracil (370 mg/m2) with high-dose (175 mg) or low-dose (25 mg) leucovorin and either levamisole (50 mg) or placebo. The fluorouracil and leucovorin regimen was given either monthly (as six 5-day courses with 4 weeks between the start of each course) or weekly (as 30 once-weekly doses). Levamisole or placebo was given three times daily for 3 days, repeated every 2 weeks for 12 courses. The primary endpoint was death from any cause. Survival was similar with both high- and low-dose leucovorin (70.1% v 71.0% at 3 years; P = .43) as well as recurrence rates (36.0% v 35.8%; P = .94), and with levamisole compared with placebo (69.4% v 71.5%; P = .06) as well as recurrence rates (37.0% v 34.9%; P = .16). Monthly and weekly treatments were equally effective (although this was a nonrandomized comparison), while weekly treatment was associated with significantly fewer toxic effects (neutropenia, mucositis, and diarrhea). High-dose leucovorin was not associated with a survival or recurrence benefit when compared with low-dose leucovorin. The ongoing QUASAR-1 trial aims to establish whether adjuvant chemotherapy has any worthwhile survival benefit in colorectal cancer patients with an uncertain indication following surgical resection.

Adjuvant treatment of colorectal cancer at the turn of the century: European and US perspectives

BACKGROUND

Despite early scepticism, several studies of systemic adjuvant 5-fluorouracil (5-FU)-based chemotherapy demonstrated significant benefits in high-risk colon cancer. As many clinical investigations have since been conducted in this setting, a comprehensive literature review was undertaken to clarify the role of adjuvant therapy in the treatment of colorectal cancer.

DESIGN

Current and future adjuvant treatment approaches in colorectal cancer were reviewed, and differences in the present-day North American and European practices were highlighted.

RESULTS AND CONCLUSIONS

5-FU plus leucovorin for six months is generally considered the 'standard' adjuvant treatment in Dukes' stage C (stage II) colon cancer. Large-scale international trials of other strategies are required to provide further advances in treatment outcome. Following the lead of the USA Intergroup trials, a recently initiated cooperative effort, the Pan-European Trials in Adjuvant Colon Cancer (PETACC), may serve as a European model for such investigations. In T3 and/or lymph-node positive rectal cancer, postoperative (chemo)radiotherapy in the USA is considered the adjuvant treatment of choice. However, most European investigators have advocated for preoperative intensive short-course irradiation instead. Randomized trials in this area are ongoing. In the near future, new drugs for the treatment of colorectal cancer may lead to tailored therapies.

Human antibodies in cancer and autoimmune disease

In recent years, a number of novel human autoantigens and tumor-associated antigens have been identified using patient sera. Several of these antigens have been used as diagnostic markers, but defining their role in disease pathogenesis has been hampered by the lack of cloned human antibodies and antigens. Focusing on the solid cancers of the breast and colon and on autoimmune hematologic diseases, we are studying the role of human antibodies in disease pathogenesis. We have generated several human monoclonal autoimmune and cancer-associated antibodies, using antibody phage display technology, and have identified, cloned, and expressed their corresponding (novel) antigens. Using the monoclonal human antibodies as probes, we are elucidating the processes that lead to the generation of these antibodies and their possible pathogenic or protective effect. These studies may lead to the development of reagents for diagnosis and therapeutic intervention of these important diseases.

Comparison of fluorouracil with additional levamisole, higher-dose folinic acid, or both, as adjuvant chemotherapy for colorectal cancer: a randomised trial. QUASAR Collaborative Group

BACKGROUND

Standard adjuvant chemotherapy for colorectal cancer consists of fluorouracil with folinic acid or levamisole. The large QUASAR randomised trial aimed to investigate (in a two x two design) whether use of a higher dose of folinic acid or addition of levamisole to fluorouracil and folinic acid improved survival.

METHODS

Patients with colorectal cancer, without evident residual disease, were randomly assigned fluorouracil (370 mg/m2) with high-dose (175 mg) or low-dose (25 mg) L-folinic acid and either active or placebo levamisole. The fluorouracil and folinic acid could be given either as six 5-day courses with 4 weeks between the start of the courses or as 30 once-weekly doses. Levamisole (50 mg) or placebo was given three times daily for 3 days repeated every 2 weeks for 12 courses. The primary endpoint was mortality from any cause. Analyses were by intention to treat.

FINDINGS

Between 1994 and 1997, 4,927 patients were enrolled. 1,776 had recurrences and 1,576 died. Survival was similar with high-dose and low-dose folinic acid (70.1% vs 71.0% at 3 years; p=0-43), as were 3-year recurrence rates (36.0% vs 35.8%; p=0.94). Survival was worse with levamisole than with placebo (69.4% vs 71.5% at 3 years; p=0.06), and there were more recurrences with the active drug (37.0% vs 34.9% at 3 years; p=0.16).

INTERPRETATION

The inclusion of levamisole in chemotherapy regimens for colorectal cancer does not delay recurrence or improve survival. Higher-dose folinic acid produced no extra benefit in these regimens over that from low-dose folinic acid. Trials of chemotherapy versus no chemotherapy will show whether these four treatments are equally effective or equally ineffective.

Efficacy of Adjuvant Fluorouracil and Folinic Acid in B2 Colon Cancer

PURPOSE: The goal of this analysis was to determine whether fluorouracil (FU) and folinic acid (leucovorin, LV) is an effective adjuvant therapy for patients after potentially curative resection of colon cancer in patients with B2 tumors.

PATIENTS AND METHODS: One thousand sixteen patients with B2 colon cancer entered onto five separate trials were randomized to FU + LV or observation. A pooled analysis for event-free (EFS) and overall survival (OS) using a stratified log-rank and Cox model was performed.

RESULTS: The median follow-up duration was 5.75 years. Patients receiving FU + LV did not experience a significant increase in EFS or OS. The hazards ratio at 5 years was 0.83 (90% confidence interval, 0.72 to 1.07) for EFS and 0.86 (90% confidence interval, 0.68 to 1.07) for OS. The 5-year EFS was 73% for controls and 76% for FU + LV. The 5-year OS was 80% for controls and 82% for FU + LV. Increasing age and poorly differentiated tumors were significant indicators of poor prognosis (P < .02).

CONCLUSION: This data set does not support the routine use of FU + LV in all patients with B2 colon cancer. Longer follow-up may identify a small benefit. At present, studies in B2 colon cancer designed with a no-treatment control arm should be considered appropriate.

5-fluorouracil: a pharmacological paradigm in the use of cytotoxics

1. Painstaking progress in drug development is well illustrated by 5-fluorouracil (5FU), originally designed 40 years ago as a fluorinated analogue of the naturally occurring base uracil. Innovative pharmacokinetic and pharmacodynamic strategies have seen significant clinical improvements for cancer patients over the past decade. 2. 5-Fluorouracil acts by three main mechanisms. Principally, the intermediate metabolite fluorodeoxyuridine monophosphate inhibits a key enzyme in pyrimidine biosynthesis, namely thymidylate synthase (TS). Additionally, 5FU is metabolized to ribo- and deoxy-ribonucleotides, which act as false bases for incorporation into RNA and DNA. 3. Biomodulation of 5FU has been attempted with methotrexate (MTX), folinic acid, interferons, cisplatin and radiotherapy. Methotrexate augments the actions of 5FU by inhibiting dihydrofolate reductase and decreasing the folate pool required for pyrimidine biosynthesis, inhibiting TS via MTX-polyglutamate and directly inhibiting purine biosynthesis. Interferons increase steady state concentrations of 5FU. 5-Fluorouracil enhances the cytotoxicity of cisplatin and radiotherapy by inhibiting DNA repair. Folinic acid enhances TS inhibition by increasing the intracellular pool of folates that stabilize the 5FU-TS complex. 4. 5-Fluorouracil has a short plasma half-life. Thymidylate synthase inhibition is limited to the S-phase of the cell cycle and only a small fraction of most cancer cells are in S-phase at any one time. Increased response rates seen with infusional protocols may reflect the effective recruitment of additional mechanisms of cytotoxicity, not dependent on cell cycle, including effects on RNA synthesis. 5. Patients with localized metastatic disease may benefit from locoregional treatments. These include hepatic intra-arterial therapy with related compounds, such as floxuridine, which reach high concentrations at sites of tumour, while systemic toxicities are minimized by efficient hepatic clearance. 6. Recent developments include orally bioavailable formulations, such as ftorafur, capecitabine and the combination of 5FU with the dihydropyrimidine phosphate dehydrogenase inhibitor ethynyluracil. Recognition of diurnal variation in the activity of such key enzymes as DPD has led to the administration of 5FU at regulated, variable infusion rates (chronomodulation). These promising pharmacological approaches may further improve clinical outcomes in common cancers.

GIVIO-SITAC 01: A randomized trial of adjuvant 5-fluorouracil and folinic acid administered to patients with colon carcinoma--long term results and evaluation of the indicators of health-related quality of life. Gruppo Italiano Valutazione Interventi in Oncologia. Studio Italiano Terapia Adiuvante Colon

BACKGROUND

In 1989, the authors began a randomized trial to determine whether 5-fluorouracil and high dose folinic acid (HD-FUFA) would increase the event free and overall survival of patients with resectable Dukes B and C (AJCC/UICC Stage II and Stage III) colon carcinoma, and to assess the toxicity of the treatment and its impact on selected health-related quality-of-life indicators. Early results were published as a part of an international multicenter pooled analysis (IMPACT) in 1995. The purpose of this report is to update the survival data for patients enrolled in the trial and describe their reported perceptions of their own health and quality of life.

METHODS

The trial involved multiple treatment centers, with a centralized randomization between surgery alone and surgery with chemotherapy. The HD-FUFA regimen employed consisted of 5-fluorouracil (370 mg/m2) plus folinic acid (200 mg/m2) administered daily for 5 days every 4 weeks for 6 cycles. Patients' perceptions of their own health status were obtained by means of 3 self-administered questionnaires, which were completed by patients at the time of discharge from the treatment center and at 6 and 24 months after randomization.

RESULTS

Overall, 888 patients with resected Dukes B2 and C colon carcinoma were enrolled in the trial. HD-FUFA significantly reduced mortality by 25% (95% confidence interval, 5-41%; P=0.02) and events by 31% (95% confidence interval, 14-45%; P < or = 0.001). Compliance with treatment was good; more than 80% of patients completed the planned therapy. Toxicity was mild, and oral mucositis was the main side effect. None of the health-related quality-of-life parameters investigated (emotional status, worry about the future, changes in social life, impact of the disease, follow-up, and global quality of life) seemed to be affected by the treatment to which patients were allocated. A positive trend in the evolution of patients' psychologic status was observed.

CONCLUSIONS

Long term results of this SITAC study confirm that HD-FUFA is a well-tolerated, effective 6-month adjuvant regimen for patients with colon carcinoma that has no detrimental effect on their quality of life.

Combined intravenous and intraperitoneal chemotherapy with fluorouracil + leucovorin vs fluorouracil + levamisole for adjuvant therapy of resected colon carcinoma

Adjuvant chemotherapy with fluorouracil (FU) and levamisole or FU/leucovorin (LV) has been established as effective adjuvant treatment for patients with stage III colon cancer. Among several other promising treatment strategies in resected colon cancer, intraperitoneal anti-cancer drug administration with its appealing rationale of counteracting microscopic residual disease on peritoneal surfaces and occult metachronous liver metastases by achieving high intraportal drug concentrations has not yet undergone sufficient clinical evaluation. To determine whether a combination of this locoregional therapeutic concept with systemic intravenous administration of FU/LV would yield better results than conventional adjuvant chemoimmunotherapy with FU/levamisole, the present randomized study was initiated. A total of 241 patients with resected stage III or high-risk stage II (T4N0M0) colon cancer were randomly assigned to 'standard therapy' with FU and levamisole, given for a duration of 6 months, or to an investigational arm, consisting of LV 200 mg m(-2) plus FU 350 mg m(-2), both administered intravenously (days 1-4) and intraperitoneally (days 1 and 3) every 4 weeks for a total of six courses. In patients with stage II disease, no significant difference was noted between the two arms after a median follow-up time of 4 years (range 2.5-6 years). Among 196 eligible patients with stage III disease, however, a comparative analysis of the two treatment groups suggested both an improvement in disease-free survival (P = 0.0014) and a survival advantage (P = 0.0005), with an estimated 43% reduction in mortality rate (95% confidence interval 26-70%) in favour of the investigational arm. In agreement with its theoretical rationale, combined intraperitoneal and intravenous FU/LV was particularly effective in reducing locoregional tumour recurrences with or without liver or other organ site involvement (9 vs 25 patients in the FU/levamisole arm; P = 0.005). Treatment-associated side-effects were infrequent and generally mild in both arms, although a lower rate of severe (WHO grade 3) adverse reactions was noted in patients receiving locoregional plus intravenous chemotherapy (3% vs 12%; P = 0.01). The results of this trial suggest that combined intraperitoneal plus systemic intravenous chemotherapy with FU/LV is a promising adjuvant treatment strategy in patients with surgically resected stage III colon carcinoma.

Adjuvant therapy for resectable rectal and colonic cancer

BACKGROUND

Recurrence of rectal and colonic carcinoma remains substantial despite apparently curative surgery. Adjuvant therapy has been applied to improve prognosis.

METHODS

This review evaluates the use of adjuvant therapy in the management of resectable rectal and colonic carcinoma. It assesses critically the evidence supporting the addition of radiotherapy, chemotherapy, chemoradiotherapy and other treatment modalities to optimal surgery.

RESULTS

In the case of rectal tumours, preoperative is more effective than postoperative radiotherapy; It can significantly reduce the incidence of local tumour recurrence. A number of trials have tended towards showing a survival advantage and a recent large randomized trial has shown a significant improvement in survival in patients with Dukes C tumours. Postoperative chemoradiotherapy is associated with a survival benefit and is standard therapy in the USA, although it is associated with increased toxicity. The effectiveness of preoperative chemoradiotherapy is currently being investigated. Postoperative fluorouracil-containing chemotherapy has resulted in a survival advantage in patients with Dukes C colonic tumours; such therapy may be administered either systemically or intraportally. The evidence of benefit with rectal tumours is more limited. Immunotherapy has been studied to a limited extent and the use of a tumour-directed monoclonal antibody has produced a survival advantage in a single trial.

CONCLUSION

Preoperative radiotherapy and postoperative chemoradiotherapy can produce a survival advantage in patients with Dukes C rectal carcinoma and reduce local recurrence. Postoperative fluorouracil-containing chemotherapy can produce a survival advantage in those with Dukes C colonic cancer. The optimal use and combination of adjuvant therapy remains uncertain.

[Recent advances in adjuvant chemotherapy in colonic cancers]

Carcinoma of the large bowel is one of the most common malignant disease. In France, 15,000 died each year from the metastatic or locoregional progression of this cancer. In the past, effective surgical adjuvant therapy has been an elusive goal with no evidence of benefit from chemotherapy or immunotherapy. However, a meta-analysis published in 1988 showed that one-year adjuvant chemotherapy using 5-fluorouracil (5-FU) containing regimens may slightly improve survival. Accelerated progress has been made since 1990: in colon cancer with regional nodal metastasis (stage C tumor), therapy with combined 5-FU and levamisole has resulted in a 33% reduction in the death rate. Controlled clinical trials demonstrated improved tumor response rates when the combination of 5-FU and leucovorin was compared with single-agent 5-FU in patients with metastatic colorectal cancer. Recent results indicate that this combination is effective in preventing tumor relapse and improving survival in patients with high risk colon cancer (especially stage C tumor). The comparison of 5-FU and leucovorin to 5-FU and levamisole is ongoing; the preliminary results of these controlled trials showed that 6 months of adjuvant therapy with 5-FU and leucovorin is as effective as the standard 12 months 5-FU and levamisole regimen and less toxic. No clear adjuvant benefit has been established in patients with Dukes' stage B2 colon cancer. The lack of statistical power of the trials and the 80% overall survival rate of these patients may explain these negative results. Almost all the specialists of these tumors considered that it is possible to select patients who are at sufficiently high risk of recurrence so that treatment can be justified. These patients are those who presented initially with tumor perforation or obstruction, adherence to or invasion of adjacent organs, young patients. Clinical trials suggest a survival benefit from the direct portal administration of the 5-FU in the immediate post-operative period, although the magnitude of the effect is less than that seen in the systemic therapy trials.

The need for a multidisciplinary approach in the treatment of advanced colorectal cancer: a critical review from a medical oncologist and surgeon

Over the last 10 years important advances have been made in the treatment of patients with advanced colorectal cancer, particularly with surgery either alone or in combination with radiotherapy. Furthermore, despite early scepticism, several chemotherapy studies have now reported significant clinical benefits with 5-FU-based regimens and promising results have also been reported with newer agents such as raltitrexed and irinotecan. Taken together these advances now enable a significant proportion of patients to undergo treatment which will improve their quality of life, prolong survival and even result in cure in certain cases. Patients with advanced colorectal cancer can only benefit from these important advances, however, if a truly multidisciplinary approach to patient care is adopted which requires integration of the roles of the surgeon, medical oncologist and radiotherapist.

Preoperative carcinoembryonic antigen predicts outcomes in node-negative colon cancer patients: a multivariate analysis of 572 patients

BACKGROUND

Although prospective trials have demonstrated that postoperative chemotherapy for node-positive colon cancer patients provides survival benefit, no improvement in survival has been documented for node-negative colon cancer patients. There are, however, a subset of node-negative patients that go on to die of their disease. We hypothesize that this subset of node-negative patients may benefit from postoperative chemotherapy. We analyzed a large cohort of node-negative colon cancer patients from a single institution to determine prognostic factors that predict which patients with node-negative colon cancer might experience recurrence and can benefit from postoperative chemotherapy.

STUDY DESIGN

A review of the prospective database for colorectal cancer at Memorial Sloan-Kettering Cancer Center (MSKCC) between 1985 and 1993 identified 572 patients who underwent curative resection for node-negative colon cancer (T(1,2,3,4)N0M0). Demographic, serum, and pathologic factors were analyzed for prognostic significance. Survival was calculated by the method of Kaplan-Meier and compared by log rank test. Multivariate analysis was calculated by the Cox proportional hazard model.

RESULTS

Median follow-up was 35 months. Factors predictive of survival by univariate analysis include tumor stage, overall stage, and preoperative serum carcinoembryonic antigen (CEA) elevation. By multivariate analysis, overall stage and preoperative serum CEA level predicted survival.

CONCLUSIONS

Routine histologic and demographic factors do not predict outcome in node-negative colon cancer patients. Preoperative CEA and overall stage predict survival by multivariate analysis. Preoperative CEA elevation in node-negative patients identifies a group of patients that has a poor prognosis and defines a subset of patients who may benefit from postoperative chemotherapy.

Relevance of tumoral folylpolyglutamate synthetase and reduced folates for optimal 5-fluorouracil efficacy: experimental data

The purpose of this study was to investigate folate-related predictors of 5-fluorouracil (5-FU) cytotoxicity in the presence or absence of l-folinic acid (l-FA). Intracellular concentrations of the reduced folates (tetrahydrofolate + 5,10-methylenetetrahydrofolate) and folylpolyglutamate synthetase (FPGS) activity were determined in 14 human cancer cell lines expressing a spontaneous sensitivity to 5-FU. On these 14 cell lines grown without l-FA supplementation, a significant positive correlation was demonstrated between basal intracellular folate concentration and FPGS activity. 5-FU sensitivity (IC50 range 0.6-25.4 microM) was not related to the basal intracellular folate concentration, whereas, significantly, it was linked to FPGS activity (range 2.5-11.1 pmol/min/mg protein): the higher the FPGS activity, the greater the 5-FU sensitivity. Under l-FA supplementation (0.01-300 microM), intracellular reduced folates increased continuously without evidence of saturation in all cell lines; the pattern of accumulation was independent of the FPGS activity. l-FA enhanced 5-FU cytotoxicity by a factor of 1.9-6.4 in 12 of the 14 cell lines. In the 12 FA-sensitive cell lines, the l-FA concentrations allowing 90% of maximum 5-FU potentiation [l-FA]90 ranged between 0.7 and 107.9 micro M (median 1.9); in contrast, the intracellular concentrations of reduced folates allowing 90% of maximum 5-FU potentiation were much less variable (range 7.6-38.3, median 24.8 pmol/mg protein). In the presence of [l-FA]90, 5-FU sensitivity remained significantly correlated to the basal FPGS activity. In addition, reduced folates were measured in 96 tumoral samples (50 head and neck, 16 colon, 30 liver metastases from colorectal cancer) taken before treatment. Almost all investigated tumours had folate concentrations below the median concentration required for optimal 5-FU potentiation in vitro: median levels (range, pmol/mg protein) were 3.8 (0-17.7) for head and neck, 5.8 (2.3-12.0) for colon and 12.1 (1.7-118.5) for liver metastases. Above all, these data establish the relevance of FPGS activity for predicting the efficacy of 5-FU modulated by FA or not and point to the potential clinical interest of FPGS determination in human tumours.

Recent developments in adjuvant chemotherapy for colorectal cancer

Recent developments in the use of systemic chemotherapy and intraportal chemotherapy in the treatment for colorectal cancer suggests that a reduction in mortality is achievable. This paper provides an overview of the management of colorectal cancer and the rationale behind adjuvant chemotherapy. A review of the current research literature published from both America and Europe will follow. Finally, the limitations and implications of the reviewed data will be discussed.

Adjuvant medical therapy for colorectal cancer

In the mid-1980s, trials of adjuvant therapy for colon cancer in the United States had a "no treatment" arm, which reflected the belief that effective adjuvant chemotherapy did not exist for patients with surgically resected disease at high risk for recurrence. However, with the observation in the early 1990s that postsurgical adjuvant 5-FU plus levamisole reduced tumor recurrence and ultimately increased overall survival in stage III colon cancer, the potential of effective adjuvant chemotherapy was realized. Questions about the duration of adjuvant chemotherapy, the specifics of chemotherapy schedule/drug selection, and its use in stage II colon cancer are beginning to be clarified in large, randomized adjuvant therapy trials. In rectal carcinomas, combined modality postoperative pelvic irradiation plus chemotherapy for stage II and III disease has been shown to reduce both local and systemic recurrences and to prolong survival compared with that in patients treated with local surgery and radiation. Again, large randomized trials are attempting to clarify both the optimal chemotherapeutic agents and schedules to be used and also whether preoperative combined modality therapy can improve the resectability rate, rate of sphincter preservation, and survival. Future trials will examine new agents shown to be effective in advanced disease as well as monoclonal antibodies, such as MoAb 17-1A, that may have selective activity in minimal disease. Improvement in overall survival remains the ultimate endpoint of future adjuvant therapy trials; however, trials will also critically examine toxicity, quality of life, pharmacoeconomics, and genetic and biologic correlates that may help select more appropriate candidates for adjuvant therapies.

High-versus low-dose levo-leucovorin as a modulator of 5-fluorouracil in advanced colorectal cancer: a 'GISCAD' phase III study. Italian Group for the Study of Digestive Tract Cancer

BACKGROUND

Although leucovorin (LV) + 5-fluorouracil (5-FU) is considered the treatment of choice for advanced colorectal cancer in most countries, the optimal schedule of this combination has not yet been established. Low-dose LV appears to be as active as high-dose LV in the daily-times-five regimen, but no randomized study of the levorotatory stereoisomer (6S-LV) given at two different dose levels has been published.

PATIENTS AND METHODS

Between November 1991 and June 1994, 422 patients (all with measurable disease previously untreated with chemotherapy) were randomized to 6S-LV (100 mg/sqm/i.v.) + 5-FU (370 mg sqm/15 min i.v. infusion), both administered for 5 days every 28 days (arm A), or to 6S-LV (10 mg/sqm/i.v./5-FU (doses as above), also given for 5 days every 28 days (arm B). The primary endpoint of the study was the comparison of response rates (WHO criteria): the secondary endpoint was the assessment of survival and tolerability. No evaluation of the quality of life or the symptomatic effect of treatment was planned.

RESULTS

The response rate was 9.3% in arm A (95% CI: 5.4-13.1), with 2 CR and 18 PR, and 10.7% in arm B (95% CI: 6.5-14.9), with 3 CR + 19 PR, without any significant difference (P = 0.78). The median time to progression was eight months in both groups and overall survival was 11 months, with no difference between treatments. Toxicity mainly consisted of gastrointestinal side effects (mucositis and diarrhoea), which were rarely severe (grade 3-4: 5%-10% of patients) and similar in the two groups.

CONCLUSIONS

In this large-scale multicentre trial, the low and high doses of 6S-LV appeared to be equivalent in terms of the biochemical modulation of 5-FU in advanced colorectal cancer although, for several reasons (including the timing and the strict criteria of response evaluation, the high number of patients with unfavourable prognostic factors, the multi-institutional nature of the study, the dose and modality of 5-FU administration), the response rate was lower than that reported in some of the other published studies. Given the considerable difference in economic cost between the two dosages, the use of high-dose 6S-LV in the daily-times-five regimen is not recommended in clinical practice.

Critical factors for optimizing the 5-fluorouracil-folinic acid association in cancer chemotherapy

BACKGROUND

The 5-fluorouracil (FU)-folinic acid (FA) association has demonstrated clinical efficacy in colorectal cancer, both in adjuvant and metastatic situations. However, there is no clear consensus about the optimal FU-FA schedule and dose. In addition, it would be of interest to identify FU-FA-responsive tumors.

DESIGN

Our purpose was to review preclinical and clinical data dealing with prediction of FU-FA sensitivity and optimization of FU-FA schedules.

RESULTS

Preclinical studies have highlighted the importance of thymidylate synthase (TS), the cellular target of the FU-FA mechanism of action, for predicting FU sensitivity. It appears that the more sensitive cell lines express the lowest TS activity. Interestingly, the cell lines sensitive to FA supplementation are those more sensitive to FU. The role of TS in FU-FA responsiveness has been clearly demonstrated in patients with colorectal and gastric cancers. Preliminary in vitro and clinical data have shown that the folylpolyglutamate synthetase (FPGS), the enzyme responsible for folate polyglutamylation, is another promising tool for identifying FU-FA-responsive tumors. So far, results of clinical trials do not form a clear consensus regarding the need to administer high FA doses for improving FU-FA treatment. Experimental studies on human cancer cell lines have demonstrated the wide variability among cell lines, ranging from 0.05 to 200 microns, of 1 FA concentrations required for maximal FU potentiation. In addition, pharmacokinetic studies have reported a significant variability of active folates in plasma after administration of standard-dose FA. Altogether, these observations favour high-dose FA administration to achieve high folate concentrations in plasma and thus to counteract the variability of the 1 FA concentrations required. With respect to the choice of FU-FA schedule, it appears from experimental data that increasing the duration of exposure to FA enhances FU-FA cytotoxicity, probably through an increased formation of reduced folate polyglutamate forms. Considering the S-phase specificity of FU cytotoxicity as well as its rapid elimination from plasma, a schedule of prolonged exposure to both FU and FA should be considered preferable.

CONCLUSIONS

Results of the new FU-FA administration schedules such as the one consisting of a 2-hour FA administration followed by a combination of FU bolus and FU infusion, or the chronomodulated FU-FA infusion, open up promising approaches for improving the therapeutic index of FU-FA chemotherapy. Finally, future clinical studies should investigate tumoral parameters pharmacologically linked to FU-FA sensitivity such as pre-treatment TS and FPGS activities. Such tumoral investigations along with FU and FA pharmacokinetic investigations should provide a better understanding of inter-patient variability in response to FU-FA therapy and an optimal management of this chemotherapy regimen.

Ganciclovir treatment of active hepatitis B virus infection in a heart transplant patient

Hepatitis B virus (HBV) infection in patients who undergo organ transplantation is a serious illness, associated with progressive and often fatal liver disease. Attempts at eradication of infection with antiviral agents, such as interferon and adenine arabinoside, have produced disappointing results. Similarly, prevention of HBV reinfection with the use of passive immunization with hepatitis B immunoglobulin or a combination of active and passive immunization have not been uniformly successful. We report the successful use of ganciclovir, a synthetic analogue of 2-deoxyguanosine, in a heart transplant patient with active HBV infection. The patient developed decompensated liver disease with ascites, edema, and marked derangement of liver tests despite drastic reduction in immunosuppressive therapy. Ganciclovir therapy was administered intravenously, and the patient showed remarkable improvement with clinical recovery and normalization of the liver tests. Moreover, the serum HBV DNA and hepatitis B e antigen became undetectable. Ganciclovir was a safe and effective treatment of HBV infection in this transplant patient.

Postoperative chemotherapy for colorectal cancer by combining 5-fluorouracil infusion and 1-hexylcarbamoyl-5-fluorouracil administration after curative resection

BACKGROUND

Colorectal cancer is one of the major malignant diseases and, recently, its incidence appears to be increasing. Surgical resectability is an important prognostic determinant; however, recurrent tumors are commonly noted, even after apparently curative surgery. Because such metastatic disease cannot be cured, better adjuvant therapies are urgently called for.

METHODS

We studied the effect of postoperative chemotherapy using 5-fluorouracil (5-FU) infusions and 1-hexylcarbamoyl-5-fluorouracil (HCFU) oral administration for curatively resected Stage II to IV colorectal cancer. This study was prospectively randomized and controlled and 251 (93.3%) of 269 patients were determined to be candidates for statistical assessment. The inductive regimen for Group A included a total of 6 5-FU intravenous injections, 10 mg/kg, on postoperative days 0, 1, 2, 7, 8, and 9. For maintenance therapy, Group A also received oral HCFU, 300 mg daily for 52 weeks beginning 2 weeks after surgery. The regimen for Group B included only 5-FU injections of Group A.

RESULTS

There were no differences in the prognostic factors or doses of 5-FU between Groups A and B. In addition, no difference was observed in the toxicity rate between the two groups. Group A, with 5-FU infusions plus oral HCFU administration, produced a reduction in the recurrence rate and a prolongation of the survival time for patients with rectal cancer. In a retrospective analysis, this protocol was also effective for patients with Stage III to IV, wall invasion-positive, and lymph node metastasis-positive colorectal cancers.

CONCLUSIONS

This study suggests that the combination of 5-FU infusions and the continuous oral administration of HCFU is a reasonable therapeutic approach for patients with surgically resected colorectal cancer and a high risk of recurrence.

Adjuvant treatment of colon and rectal cancer: impact of chemotherapy, radiotherapy, and immunotherapy on routine postsurgical patient management. Forschungsgruppe Onkologie Gastrointestinaler Tumoren (FOGT)

Colon cancer patients with UICC stage III or T4 N0 M0 stage II should receive postoperative adjuvant therapy, since relapse rates are high and surgical outcome has been improved by adjuvant treatment. The standard treatment is 5-fluourouracil plus levamisole; an alternative option is the combination of 5-fluourouracil and folinic acid. Stage II (T3 N0 M0) colon cancer patients should not receive adjuvant treatment outside of studies. Rectal cancer patients of stage II or III should receive postoperative radiochemotherapy with 45-54.4 Gy and 5-fluourouracil as standard treatment. Patients not eligible for radiotherapy may receive adjuvant chemotherapy only. Studies need to be conducted to improve adjuvant therapy in colorectal cancer. All qualified patients should be treated within these studies requiring sufficient patient numbers, as well as comparable surgical procedures, proper patient selection and stratification criteria, drug and dose intensities. Intraportal infusion may be as effective as systemic adjuvant treatment; the tumor type and stage for which benefit from this kind of treatment is consistently significant needs to be defined, since intraportal infusion of all resectable colorectal cancers is overtreatment. Both surgery and histopathological staging may be improved in some centers, and these require standardization and quality control.

Combined intraperitoneal plus intravenous chemotherapy after curative resection for colonic adenocarcinoma

Patients who underwent potential curative surgery for colonic adenocarcinoma were enrolled in a prospectively randomised, controlled clinical trial of combined intraperitoneal (i.p.) plus systemic intravenous (i.v.) chemotherapy with 5-fluorouracil (5-FU) and leucovorin (LV). We investigated whether this adjuvant treatment approach, specifically addressing the risk of peritoneal and hepatic recurrence, could improve disease-free and overall survival. Between May 1988 and December 1990, 121 patients with resected stage III or high-risk stage II (T4N0M0) colon cancer were randomly assigned for observation (which was considered standard care until the NIH consensus conference) or adjuvant chemotherapy with LV (200 mg/m2) plus 5-FU (350 mg/m2), both given i.v. (days 1-4) and i.p. (days 1 and 3) every 4 weeks for a total of six courses. After a median follow-up time of 4.6 years, a comparative analysis between the two groups of patients suggested both an improvement in disease-free survival (75% versus 58%; P = 0.06) and a survival advantage (78% versus 63%; P = 0.05) in favour of adjuvant chemotherapy. The sites of recurrence were also different, i.e. local regional and intrahepatic tumour recurrences were observed in only 6/58 (10%) and 5/58 (9%) adjuvant treated patients as compared to 11/60 (18%) and 10/60 (17%) observed patients. The overall benefit of adjuvant therapy appeared to be greatest in patients with stage III colon cancer. Treatment-associated toxicity was infrequent and generally mild with only 5% experiencing severe (WHO grade 3) adverse reactions. Interim results of this adjuvant trial suggest that combined i.p. plus systemic i.v. chemotherapy with 5-FU and LV represents a potentially effective adjuvant regimen in stage II/III colon cancer.

Efficacy of adjuvant fluorouracil and folinic acid in colon cancer. International Multicentre Pooled Analysis of Colon Cancer Trials (IMPACT) investigators

The role of fluorouracil and folinic acid and adjuvant therapy for colon cancer is not clear. We undertook independently three randomised trials to find out the efficacy of fluorouracil and high-dose folinic acid after surgery for Dukes' B and C stage colon cancer. The three studies by the Gruppo Interdisciplinare Valutazione Interventi Oncologia (GIVIO), the National Cancer Institute Canada Clinical Trials Group (NCIC-CTG), and the Fondation Française de Cancerologie Digestive (FFCD) were pooled for combined analysis. Each trial was multicentre and used the same treatment regimen (fluorouracil 370-400 mg/m2 plus folinic acid 200 mg/m2 daily for 5 days, every 28 days for 6 cycles). A pooled analysis of the results was done on the basis of a previously agreed protocol when there were sufficient events to detect at least a 10% reduction in mortality with 80% power. 1526 patients with resected B (56%) and C (44%) carcinoma of the colon were enrolled and 1493 were confirmed as eligible. 736 were assigned to the treatment group and 757 to the control group. Fluorouracil/folinic acid significantly reduced mortality by 22% (95% CI 3-38; p = 0.029) and events by 35% (22-46; p < 0.0001), increasing 3-year event-free survival from 62% to 71% and overall survival from 78% to 83%. Compliance with treatment was good; more than 80% of patients completed the planned treatment. Side-effects were clinically acceptable with only 1 treatment-related death. The commonest side-effects were gastrointestinal, but severe toxic effects (WHO grade 4) occurred in fewer than 3% of cases. We conclude that fluorouracil plus high-dose folinic acid is a well-tolerated and effective 6-month adjuvant regimen for colon cancer.

Treatment of chronic hepatitis B

Chronic infection with the hepatitis B virus (HBV) is a major cause of worldwide morbidity and mortality. A large number of therapeutic approaches has been tried, including interferon (IFN), nucleoside analogues and immunomodulators. To date controlled clinical trials have shown that only IFN is of long-term value but many patients fail to respond to treatment. New approaches to treating patients with IFN-resistant hepatitis B are currently undergoing clinical and experimental evaluation, and it seems likely that new therapeutic agents will be available in the near future.