Leucovorin and fluorouracil with or without oxaliplatin as first-line treatment in advanced colorectal cancer

Oxaliplatin and protracted continuous 5-fluorouracil infusion in patients with pretreated advanced colorectal carcinoma

BACKGROUND

Both OHP and 5-FU are clinically active as single agents in the treatment of metastatic colorectal cancer (MCRC). Clinical and laboratory studies suggest a synergistic interaction between these agents. This phase II study was performed to evaluate the activity of a schedule including OHP and protracted 5-FU infusion in 5-FU-resistant MCRC.

PATIENTS AND METHODS

From October 1997 to January 2000, 50 patients with measurable progressive MCRC after one or more 5-FU-based regimens were treated. OHP (2-3-hour i.v. infusion) on day 1 and 5-FU (protracted i.v. infusion using elastomeric/electronic pump through a central venous catheter) on days 1-21 were administered every 3 weeks, at the following 4 dose levels: 1) OHP 100 mg/m2 + 5-FU 200 mg/m2 (21 patients); 2) OHP 100 mg/m2 + 5-FU 250 mg/m2 (3 patients); 3) OHP 130 mg/m2 + 5-FU 200 mg/m2 (10 patients); 4) OHP 130 mg/m2 + 5-FU 250 mg/m2 (6 patients).

RESULTS

Objective responses were 1 (2%) CR; 10 (20%) PR, for a median duration of 8 months; 23 (46%) stable diseases, for a median duration of 6 months: 16 (32%) progressions. CR + PR was higher in patients who had previously received no more than one line of chemotherapy for metastatic disease as compared with patients who had received two or more lines of therapy (33% vs. 5%, P < 0.01). The median time to progression was four months (one to nine). All dose levels (313 cycles) were well tolerated with mild toxicity. Major toxicity (grade 3 WHO) included: anaemia in 1 patient (2%), nausea and vomiting in 1 patient (2%), diarrhoea in 4 patients (8%) and stomatitis in 1 patient (2%); grade I and 2 peripheral neuropathy were encountered, respectively, in 30 (60%) and 8 (16%) patients. The median survival was 13 months (9-17), with 32 patients still alive after a median follow-up of 8 months.

CONCLUSIONS

This study suggests that 1) OHP plus protracted 5-FU infusion is an active combination in MCRC patients resistant to pre-treatment bolus 5-FU; 2) it has a good tolerability profile and 3) the optimum dose level is OHP 130 mg/m2 and 5-FU 250 mg/m2.

Alpha-interferon does not increase the efficacy of 5-fluorouracil in advanced colorectal cancer

Two meta-analyses were conducted to quantify the benefit of combining alpha-IFN to 5FU in advanced colorectal cancer in terms of tumour response and survival. Analyses were based on a total of 3254 individual patient data provided by principal investigators of each trial. The meta-analysis of 5FU +/- LV vs. 5FU +/- LV + alpha-IFN combined 12 trials and 1766 patients. The meta-analysis failed to show any statistically significant difference between the two treatment groups in terms of tumour response or survival. Overall tumour response rates were 25% for patients receiving no alpha-IFN vs. 24% for patients receiving alpha-IFN (relative risk, RR = 1.02), and median survivals were 11.4 months for patients receiving no alpha-IFN vs. 11.5 months for patients receiving alpha-IFN (hazard ratio, HR = 0.95). The meta-analysis of 5FU + LV vs. 5FU + alpha-IFN combined 7 trials, and 1488 patients. This meta-analysis showed an advantage for 5FU + LV over 5FU + alpha-IFN which was statistically significant in terms of tumour response (23% vs. 18%; RR = 1.26;P = 0.042), and of a borderline significance for overall survival (HR = 1.11;P = 0.066). Metastases confined to the liver and primary rectal tumours were independent favourable prognostic factors for tumour response, whereas good performance status, metastases confined to the liver or confined to the lung, and primary tumour in the rectum were independent favourable prognostic factors for survival. We conclude that alpha-IFN does not increase the efficacy of 5FU or of 5FU + LV, and that 5FU + alpha-IFN is significantly inferior to 5FU + LV, for patients with advanced colorectal cancer.

Determinants of prognosis and response to therapy in colorectal cancer

Identification of the molecular determinants of 5-fluorouracil (5-FU) and irinotecan (CPT-11) efficacy and toxicity is critically important for the development of more efficient and less toxic treatment strategies for patients with colon cancer. We have identified molecular predictors of response to chemotherapy with 5-FU and survival in patients with advanced colorectal cancer. Low gene expression levels of thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and thymidine phosphorylase (TP) are associated with response and survival. Preliminary data suggest that gene expression levels of topoisomerase I, p21, bcl-2, and ICE may be predictive of response to therapy with CPT-11. Increased toxicity seen in patients treated with CPT-11 may be explained by polymorphism in the UGT1A1 gene, which is responsible for glucuronidation of the active metabolite of CPT-11.

Irinotecan in the treatment of colorectal cancer: clinical overview

PURPOSE AND METHODS

For more than three decades, the therapeutic options for patients with advanced colorectal cancer have almost exclusively been based on fluoropyrimidines. With the recognition that topoisomerase-I (TOP-I) is an important therapeutic target in cancer therapy, irinotecan, a semisynthetic TOP-I-interactive camptothecin derivative, has been clinically established in the treatment of colorectal cancer.

RESULTS

Irinotecan was investigated as second-line chemotherapy after prior treatment with fluorouracil (FU)-based regimens in two large randomized phase III trials comparing irinotecan with either best supportive care or an infusional FU/leucovorin (LV) regimen. The outcomes of these trials established irinotecan as the standard therapy in the second-line treatment of colorectal cancer. The therapeutic value of irinotecan in the first-line treatment of metastatic colorectal cancer was investigated in two large randomized phase III trials comparing the combination of irinotecan and FU/LV with FU/LV alone. Both trials demonstrated significant superior efficacy for the combination of irinotecan and FU/LV in terms of response rate, median time to disease progression, and median survival time. Consequently, the combination of irinotecan and FU/LV has been approved as first-line chemotherapy for patients with metastatic colorectal cancer and constitutes the reference therapy against which other treatment options must be tested in the future.

CONCLUSION

In this review, the clinical rationale and update of the present clinical status of irinotecan in the treatment of colorectal cancer and future prospects of irinotecan-based combinations are discussed.

Use of the ratio of time to progression following first- and second-line therapy to document the activity of the combination of oxaliplatin with 5-fluorouracil in the treatment of colorectal carcinoma

BACKGROUND

It has been proposed that the activity of a second-line treatment regimen can be documented by showing that the time to progression (TTP) following second-line therapy is longer than the TTP following first-line therapy in the same patients.

PATIENTS AND METHODS

The ratio of TTP during first and second-line therapy, identified as the growth modulation index (GMI), was determined in 34 patients with advanced colorectal cancer. First-line chemotherapy consisted of one of several schedules of leucovorin (LV)-modulated 5-fluorouracil (5-FU) or raltitrexed. Second-line therapy consisted of the combination of LV-modulated 5-FU and oxaliplatin (1-OHP). Patients were switched to second-line therapy upon evidence of progressive disease following first-line therapy.

RESULTS

Median TTP following first-line therapy was 13 weeks (95% confidence interval (CI): 7.6-18.7), while median TTP following second-line therapy was 31 weeks (95% CI: 21.3-41.0). Sixteen patients (47%; 95% CI: 35%-59%), showed a GMI > or = 1.33, while the remaining 18 patients (53%; 95% CI: 40%-66%) had a GMI < 1.33. Log-rank analysis of the Kaplan-Meier curves of TTP following first- versus second-line therapy demonstrated a statistically significant difference in favour of second-line therapy (P = 0.0081).

CONCLUSIONS

This study demonstrates the utility of the GMI as a tool for assessing the activity of novel second-line therapeutic programs.

Ternary combination of irinotecan, fluorouracil-folinic acid and oxaliplatin: results on human colon cancer cell lines

A marked antitumour efficacy is currently obtained by oxaliplatin (LOHP)-fluorouracil (FU)-folinic acid (FA) combination and by CPT11-FU-FA combination. Logically, the triple association LOHP, CPT11 and FUFA will be soon tested in cancer patients. The aim of the present study was to compare two schedules combining SN38 (the active metabolite of CPT11, irinotecan) with FU-FA and LOHP. The two schedules differed by the SN38 position. The relative contribution of each drug in the resulting global cytotoxicity was evaluated. Two human colon cancer cell lines were used (WIDR and SW620 both p53 mutated). LOHP plus FA were applied for 2 h, just before a 48 h FU exposure. The SN38 sequence was applied for 24 h, starting either 48 h before LOHP-FA (schedule A), or just after LOHP-FA exposure (schedule B). Cytotoxicity was assessed by the 3-(4,5-demethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) test and drug interactions were analysed according to the Chou and Talalay method, based on the computation of a combination index (CI). The SN38 position significantly induces a shift from additivity-antagonism when SN38 was applied after LOHP, towards additivity-synergism when SN38 was applied first (P = 0.03). The relative contribution (RC) of each drug in the overall cytotoxicity of the triple combination was defined as the drug concentration giving 50% cell lethality (IC(50)) of the double association without that drug divided by the IC(50)of the triple association. Whatever the SN38 position, the larger contribution was made by LOHP (median RC = 2.4) and the smaller by SN38 (median RC = 1.1). In addition, the contribution of FUFA was improved when SN38 was applied first (median RC = 2.2) as compared to the opposite schedule (median RC = 1.2). Results were in agreement between the two explored cell lines. The present data should be taken into account when establishing the rationale of future trials combining CPT11, LOHP and FU-FA.

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.

Cancer Chemotherapy Update: Fluorouracil and Low-Dose Leucovorin (Mayo Regimen) for Advanced Colorectal Cancer

The increasing complexity of cancer chemotherapy makes it mandatory that pharmacists be familiar with these highly toxic agents. This column reviews various issues related to the preparation, dispensing, and administration of cancer chemotherapy, both commercially available and investigational.

Evaluation of oxaliplatin dose intensity in bimonthly leucovorin and 48-hour 5-fluorouracil continuous infusion regimens (FOLFOX) in pretreated metastatic colorectal cancer. Oncology Multidisciplinary Research Group (GERCOR)

BACKGROUND

Studies of bimonthly 48-hour regimens of high-dose leucovorin (LV) (FOLinic acid), 5-fluorouracil (5-FU) by continuous infusion combined with OXaliplatin (FOLFOX) in pretreated patients with metastatic colorectal cancer suggest that oxaliplatin dose intensity is an important prognostic factor for response rate and progression-free survival (PFS). To help define the optimal dose schedule for oxaliplatin in pretreated metastatic colorectal cancer, we retrospectively analyzed data from three phase II studies using different FOLFOX regimens (FOLFOX2, 3 and 6).

PATIENTS AND METHODS

Data on 126/161 patients were analyzed. FOLFOX2 included oxaliplatin 100 mg/m2; FOLFOX3, 85 mg/m2; and FOLFOX6, 100 mg/m2 (added to a simplified LV-5-FU regimen), all as two-hour infusions. A total of 47 patients received low dose intensity oxaliplatin (LDI: < or = 85 mg/m2/2 weeks) and 79 patients high dose intensity oxaliplatin (HDI: > 85 mg/m2/2 weeks).

RESULTS

Objective responses occurred in 31 (39%) HDI patients and 9 (19%) LDI patients (P = 0.03). Median PFS was 28 weeks, with 52% of HDI patients progression free at 6 months, and 26 weeks with 36% of LDI patients progression free at six months (P = 0.02). Increased oxaliplatin dose intensity was not associated with increased neurotoxicity or other toxicities. FOLFOX are among the most effective regimens for treating LV-5-FU-resistant metastatic colorectal cancer.

CONCLUSIONS

This study shows that oxaliplatin dose intensification significantly improves response rate and PFS in pretreated metastatic disease without increasing severe toxicity.

Oxaliplatin. A review of its pharmacological properties and clinical efficacy in metastatic colorectal cancer and its potential in other malignancies

Oxaliplatin is a platinum compound that inhibits DNA synthesis, primarily by causing intrastrand cross-links in DNA. Oxaliplatin has a broad spectrum of antineoplastic activity and has demonstrated a lack of cross-resistance with other platinum compounds. In patients with metastatic colorectal cancer, intravenous oxaliplatin has been trialled as a monotherapy and in combination with other agents. The highest response rates were achieved when oxaliplatin was used in combination with fluorouracil/folinic acid (leucovorin; calcium folinate), typically > or = 50% in the first-line setting and 13 to 45% as a second-line therapy. First-line triple therapy with oxaliplatin and fuorouracil/folinic acid achieved significantly higher response rates and longer median progression-free survival than fluorouracil/folinic acid therapy alone. However, no significant difference in the median duration of overall survival was found. This may be a consequence of the subsequent use of oxaliplatin and/or surgery after disease progression in patients who relapsed after fluorouracil/folinic acid therapy alone. Neoadjuvant therapy with oxaliplatin/fluorouracil/folinic acid has proven beneficial in enabling surgical removal of previously unresectable liver metastases. In 2 studies, surgery with curative intent was performed in 16 and 51% of patients with initially unresectable liver metastases following oxaliplatin/fluorouracil/folinic acid therapy; the 5-year survival rates were 40 and 50%, respectively. In patients with advanced ovarian cancer, first-line therapy with oxaliplatin/cyclophosphamide achieved an objective response rate which did not differ significantly from that of cisplatin/cyclophosphamide (33 vs 42%). In addition, oxaliplatin has shown efficacy in patients with platinum-pretreated ovarian cancer and achieved objective response rates similar to paclitaxel in this setting (16 vs 17%). Promising results have also been found with oxaliplatin in patients with non-Hodgkin's lymphoma, breast cancer, mesothelioma and non-small cell lung cancer. Reversible, cumulative, peripheral sensory neuropathy is the principle dose-limiting factor of oxaliplatin therapy. Haematological and gastrointestinal toxicities occur frequently but are generally mild to moderate in intensity.

CONCLUSION

Oxaliplatin in combination with fluorouracil/folinic acid is an effective treatment option for patients with metastatic colorectal cancer, both as a first-line therapy and in patients refractory to previous chemotherapy. Although preliminary results failed to show any overall survival advantage of this regimen over fluorouracil/folinic acid alone, this may be a consequence of trial design and requires further examination. Additional clinical investigation of oxaliplatin in patients with other cancers is warranted given the promising results achieved in early trials, most notably in patients with platinum-pretreated ovarian cancer.

Phase II trial of oxaliplatin as first-line chemotherapy in metastatic colorectal cancer patients. Digestive Group of French Federation of Cancer Centers

PURPOSE

To evaluate the objective tumor response rate and safety profile of oxaliplatin when administered to patients with previously untreated metastatic colorectal adenocarcinoma.

PATIENTS AND METHODS

A total of 39 patients were entered onto this phase II trial. One patient was excluded for having had a second cancer, so the study was based on 38 patients. Patients were treated with oxaliplatin 130 mg/m2 as a 2-hour infusion on day 1, every 21 days. Patients were assessed for response every three courses. All clinical and radiologic data were reviewed by an external panel of experts, with their assessment being considered definitive.

RESULTS

Nine partial responses (PRs) were observed (response rate, 24.3%; 95% confidence interval, 11.8% to 41.2%). The median duration of response was 216+ days. Fifteen patients (40.5%) had stable disease and 13 (35.2%) had progressive disease. The median progression-free survival time for all patients was 126+ days (range, 21 to 447+). The main toxicity was peripheral sensory neuropathy. Grade 3 neurotoxicity (National Cancer Institute common toxicity criteria [NCI-CTC]) was reported in 13%. Hematologic and gastrointestinal toxicities were mild. The incidence of grade 3 neutropenia was 5.2%, while that of grade 3 or 4 thrombopenia was 7.9%. Vomiting (grade 3 or 4) occurred in 7.9% of patients and grade 3 diarrhea in 2.6%.

CONCLUSION

This phase II study provides clear evidence of the safety and efficacy of oxaliplatin monotherapy at this dose and schedule in patients with previously untreated metastatic colorectal carcinoma.