Phase III multicenter randomized trial of oxaliplatin added to chronomodulated fluorouracil-leucovorin as first-line treatment of metastatic colorectal cancer

From circadian rhythms to cancer chronotherapeutics

Mammalian circadian rhythms result from a complex organization involving molecular clocks within nearly all "normal" cells and a dedicated neuroanatomical system, which coordinates the so-called "peripheral oscillators." The core of the central clock system is constituted by the suprachiasmatic nuclei that are located on the floor of the hypothalamus. Our understanding of the mechanisms of circadian rhythm generation and coordination processes has grown rapidly over the past few years. In parallel, we have learnt how to use the predictable changes in cellular metabolism or proliferation along the 24h time scale in order to improve treatment outcome for a variety of diseases, including cancer. The chronotherapeutics of malignant diseases has emerged as a result of a consistent development ranging from experimental, clinical, and technological prerequisites to multicenter clinical trials of chronomodulated delivery schedules. Indeed large dosing-time dependencies characterize the tolerability of anticancer agents in mice or rats, a better efficacy usually results from treatment administration near the least toxic circadian time in rodent tumor models. Programmable in time multichannel pumps have allowed to test the chronotherapy concepts in cancer patients and to implement chronomodulated delivery schedules in current practice. Clinical phase I and II trials have established the feasibility, the safety, and the activity of the chronotherapy schedules, so that this treatment method has undergone further evaluation in international multicenter phase III trials. Overall, more than 2,000 patients with metastatic disease have been registered in chronotherapy trials. Improved tolerability and/or better antitumor activity have been demonstrated in randomized multicenter studies involving large patient cohorts. The relation between circadian rhythmicity and quality of life and even survival has also been a puzzling finding over the recent years. An essential step toward further developments of circadian-timed therapy has been the recent constitution of a Chronotherapy cooperative group within the European Organization for Research and Treatment of Cancer. This group now involves over 40 institutions in 12 countries. It is conducting currently six trials and preparing four new studies. The 19 contributions in this special issue reflect the current status and perspectives of the several components of cancer chronotherapeutics.

Trimetrexate as biochemical modulator of 5-fluorouracil/leucovorin in advanced colorectal cancer: final results of a randomised European study

BACKGROUND

Trimetrexate (TMTX) is a biochemical modulator of 5-fluorouracil (5-FU) and leucovorin (LV). Phase II trials have shown promising activity of 5-FU/LV/TMTX in patients with advanced colorectal cancer (ACC). This trial evaluated the effect of TMTX in combination with 5-FU/LV as first-line treatment in ACC.

PATIENTS AND METHODS

Patients with ACC were randomised to receive either intravenous LV 200 mg/m2/5-FU 600 mg/m2 or TMTX 110 mg/m2 followed 24 h later by LV 200 mg/m2/5-FU 500 mg/m2 plus oral LV rescue. Both schedules were given weekly for 6 weeks every 8 weeks. Patients were evaluated for progression-free survival (PFS), overall survival (OS), tumour response, quality of life (QoL) and toxicity.

RESULTS

A total of 365 patients were randomised. A statistically significant prolongation of median PFS was seen in patients treated with TMTX/5-FU/LV compared with 5-FU/LV (5.4 months versus 4.1 months, respectively; P = 0.03), and a trend towards a significant benefit for OS (13.4 months versus 10.5 months, respectively; P = 0.08). Tumour response, QoL and toxicity were comparable between the two arms. Diarrhoea was the most frequently occurring grade 3 or 4 toxicity (22% and 30%, respectively).

CONCLUSIONS

The addition of TMTX to a weekly regimen of 5-FU/LV results in a small but significant improvement in PFS without adding toxicity or worsening QoL in patients with ACC.

Treatment of colon and rectal cancer

During the past two decades, remarkable progress has been made in the treatment of cancers of the colon and rectum. Both oncologic and functional outcomes for this disease have improved dramatically. The reasons for the improved patient outcome in this disease include advances in knowledge of the biology of the disease, advances in surgical instrumentation and techniques, and ongoing advances in multimodality therapy, with the use of radiation and chemotherapy as an adjuvant to surgical resection. This review details many of these advances in a comprehensive manner and illustrates the necessity of a multidisciplinary approach for optimizing outcome for patients with these cancers.

Chronotherapy of colorectal cancer

Chronotherapy consists of chemotherapy delivery according to circadian rhythms. These genetically based rhythms modulate cellular metabolism and cell proliferation in normal tissues. As a result, both the host tolerance and antitumor efficacy of 5-fluorouracil (5-FU) and oxaliplatin (L-OHP), like 30 other anticancer drugs, vary largely according to the dosing time in laboratory rodents. The transfer of this concept to the clinic is aimed primarily at increasing the dose-intensity of the therapy through adjustment of drug-delivery to 24h rhythms in host tolerance. A specific technology (programmable-in-time infusion pumps) enables administration of chronotherapy to fully ambulatory patients. Phase I-III clinical trials show chronotherapy significantly increases tolerance to high doses of cancer drugs and improves antitumor activity in patients with metastatic colorectal cancer. These safe conditions of drug-delivery led to the first demonstration of the high activity of the 5-FU-leucovorin-L-OHP protocol. Chronotherapy with these three drugs also allows surgical removal of previously unresectable liver and lung metastases. This novel medico-surgical management provides hope for the cure of metastatic disease in patients with unresectable colorectal cancer metastases.

Adjuvant and neoadjuvant radiotherapy and concurrent radiochemotherapy for rectal cancer

Radical surgery with negative margins remains the most important prognostic factor in the treatment of rectal cancer. Combined modality treatment is the recommended standard adjuvant therapy for patients with locally advanced rectal cancer in the USA and in Germany. During the last decade substantial progress has been made in treatment modalities: surgical management currently includes a broad spectrum of operative procedures ranging from radical operations to innovative sphincter-preserving techniques. Specialized groups have reported excellent local control rates with total mesorectal excision (TME) alone. New and improved radiation techniques (conformal radiotherapy, intraoperative radiotherapy) and innovative schedules (protracted intravenous infusion, chronomodulated infusion) and combinations (oxaliplatin, irinotecan) of chemotherapy may have the potential to further increase the therapeutic benefit of adjuvant treatment. Moreover, the basic issue of timing of radio-(chemo-)therapy - preoperative versus postoperative - within a multimodality regimen is currently being addressed in prospective trials. Evidently, the current monolithic approaches, established by studies conducted more than a decade ago, to apply either the same schedule of postoperative radiochemotherapy to all patients with stage II/III rectal cancer or to give preoperative intensive short-course radiation according to the Swedish concept for all patients with resectable rectal cancer irrespective of tumor stage and treatment goal (e.g. sphincter preservation), need to be questioned. This review will discuss different irradiation settings in more recent and ongoing studies of perioperative radiotherapy for rectal cancer and will focus on the issue which patient should receive radiotherapy at all, and if so, how and when?

Randomized multicenter phase II trial of oxaliplatin plus irinotecan versus raltitrexed as first-line treatment in advanced colorectal cancer

PURPOSE

Irinotecan and oxaliplatin are two new agents with promising activity in advanced colorectal cancer. Based on preclinical and clinical evidence that both drugs act synergistically, a randomized phase II study was initiated to investigate the therapeutic potential and tolerance of this combination in the front-line setting.

PATIENTS AND METHODS

Ninety-two patients with previously untreated, measurable disease were randomized to receive biweekly oxaliplatin 85 mg/m(2) plus irinotecan 175 mg/m(2) or raltitrexed 3 mg/m(2) given on day 1 every 3 weeks. Upon development of progressive disease, second-line treatment with the opposite arm was effected.

RESULTS

Patients allocated to oxaliplatin/irinotecan had a significantly better radiologically confirmed response rate (43.5% v 19.6%; P =.0025) and longer progression-free survival (median, 7.1 v 5.0 months; P =.0033). Improvement in overall survival, however, did not reach the level of significance (median, 16.0 v 16.5 months; P =.3943). The response rate after cross-over was 33.3% (eight of 24) for assessable patients treated with oxaliplatin/irinotecan compared with 14.2% (three of 21) for those treated with second-line raltitrexed. Oxaliplatin/irinotecan caused more hematologic and gastrointestinal toxicities, necessitating dose reductions in 10 of the first 20 patients. After adjustment of the irinotecan starting dose from 175 to 150 mg/m(2), tolerance of treatment was acceptable; the most commonly encountered events (all grades) were neutropenia (81%), alopecia (65%), nausea/emesis (62%), peripheral sensory neuropathy (62%), and diarrhea (46%).

CONCLUSION

Oxaliplatin/irinotecan seems beneficial as first-line therapy in advanced colorectal cancer, with an acceptable toxicity profile at the reduced irinotecan dose level. Its promising therapeutic potential is supported by the high response activity noted in the raltitrexed control arm after cross-over, which may also explain the lack of a difference in overall survival.

Clinical pharmacokinetics of 5-fluorouracil with consideration of chronopharmacokinetics

Even though 5-fluorouracil (FU) is one of the oldest anticancer drugs, its use in cancer chemotherapy continues to increase. Fluorouracil is a pro-drug that requires intracellular activation to exert its effects. This makes it difficult to associate blood drug concentration with cell toxicity directly, although data from the literature show the existence of such a relationship. The relationship between FU pharmacokinetics and patient response has been explored extensively and reports attest a link between systemic drug exposure and response and survival. This has led to the concept of maximal tolerated exposure, and strategies to achieve this rely on pharmacokinetic follow-up and individual dose adjustment. More than 80% of the administered FU dose is eliminated by catabolism through dihydropyrimidine dehydrogenase (DPD), the rate-limiting enzyme. Dihydropyrimidine dehydrogenase activity is found in most tissues but is highest in the liver. Peripheral blood mononuclear cells (PBMC) are used to monitor clinically DPD activity. A significant, but weak correlation between PBMC and liver DPD activity has been observed. The relationship between PBMC-DPD activity and FU systemic clearance is weak (r2 = 0.10); thus, simply determining PBMC-DPD is not sufficient to predict accurately FU clearance. Population pharmacokinetic analysis identified patient co-variables that influence FU clearance; drug kinetics is significantly reduced by increased age, high serum alkaline phosphatase, length of drug infusion, and low PBMC-DPD. Autoregulation of FU metabolism also is suggested; inhibition of DPD activity was observed after FU administration in both colorectal cancer patients and an animal model. Circadian rhythmicity in DPD activity is suggested from both human and animal investigations. In patients receiving protracted low dose 5-FU infusion, the circadian rhythm in FU plasma concentration peaks at 11:00h and is lowest at 23:00h, on average. The inverse relationship observed between the circadian profile of FU plasma concentration and PBMC-DP activity in these same patients suggests a link between DPD activity and FU pharmacokinetics. The impact of the biological time of drug administration was also studied with short venous infusions; clearance was 70% greater at 13:00h than at 01:00h. Similarly, peak drug concentration occurred in the first half of the night in patients receiving constant rate 5-FU infusion for 2-5d. Several studies describe wide interindividual variation in the timing of the peak and trough of the 24h rhythm in DPD activity. The rational for FU chronomodulated therapy has been the circadian rhythm in host drug tolerance, which is greatest during the night time when the proliferation of normal target tissue is least. A randomized study of chronomodulated FU therapy with maximal delivery rate at 04:00h was shown clearly to be significantly more effective and less toxic than control flat FU therapy. Future research must focus on easy-to-obtain markers of specific rhythms to individualize the chronomodulated FU delivery.

Effects of different schedules of oxaliplatin treatment on the peripheral nervous system of the rat

The aim of this study was to determine the influence of oxaliplatin scheduling on the onset of peripheral neurotoxicity and ototoxicity in a rat model. Animals were treated with four different schedules of oxaliplatin using two cumulative doses (36 and 48 mg/kg intraperitoneally (i.p.)). The neuropathological examination evidenced dorsal root ganglia (DRG) nucleolar, nuclear and somatic size reduction with nucleolar segregation in the treated rats. Sensory nerve conduction velocity (SNCV) was reduced after oxaliplatin treatment, while the auditory pathway was unaffected. After treatment, platinum was detected in the kidney, DRG and sciatic nerve. After a 5-week follow-up period, recovery of the pathological changes in the DRG and sciatic nerves occurred, although platinum was still detectable in these tissues. The following conclusions may be drawn: the main targets of oxaliplatin neurotoxicity were the DRG; the shorter the interval between the injections, the higher the severity of peripheral neuropathy and this was also related to the cumulative oxaliplatin dose; the peripheral neurotoxicity tended to be reversible; ototoxicity was absent even with high cumulative doses of oxaliplatin.

Regional chemotherapy of nonresectable colorectal liver metastases with mitoxantrone, 5-fluorouracil, folinic acid, and mitomycin C may prolong survival

BACKGROUND

Regional chemotherapy of isolated, nonresectable colorectal liver metastases (CRLMs) by hepatic artery infusion (HAI) has the advantages of high response rates and the possibility of downstaging and resection of CRLMs. 5-Fluorodeoxyuridine (5-FUDR) has been the drug studied in most Phase II and III trials. The meta-analysis of the Phase III trials comparing HAI with systemic or supportive therapy confirmed an advantage for response and even survival for HAI. Hepatic artery infusion with 5-FUDR, however, is hepatotoxic, inducing sclerosing cholangitis (SC). The authors have introduced 5-fluorouracil (5-FU) with folinic acid for HAI and found equal effectivity but no SC when compared with HAI with 5-FUDR. Now, they report a new combination chemotherapy protocol based on HAI with 5-FU with FA and on in vitro Phase II studies suggesting mitoxantrone and mitomycin C as active drugs for HAI in CRLM. PATIENTS AND METHODS Between February 1993 and August 2000, 63 patients with CRLM were treated with HAI using mitoxantrone, 5-FU with FA, and mitomycin C (MFFM) via port catheters with a protocol planing up to 11 cycles of treatment. Toxicity and response were analyzed according to World Health Organization (WHO) criteria, and survival was analyzed according to Kaplan-Meier. All patients were treated with more than two HAI cycles.

RESULTS

The objective response rate (complete remission and partial remission) was 54% and primary intrahepatic progression (progressive disease) occurred in 4.8%, whereas in 41.3% of the patients the intrahepatic disease was evaluated as no change. Median survival times from the first diagnosis of CRLM or start of HAI were 25.7 months and 23.7 months, respectively, and 7 patients lived longer than 40 months. Grade 3 toxicity according to WHO occurred in 34.9%, and Grade 4 occurred in 3.2%. No toxic death or SC occurred.

CONCLUSIONS

Our new HAI protocol with MFFM seems to be superior to HAI with 5-FUDR, 5-FU with FA, and systemic chemotherapy with 5-FU and FA at acceptable toxicity. Currently, HAI with MFFM is compared with systemic chemotherapy using 5-FU and FA intravenously in a randomized Phase III trial.

An oxaliplatin-based chemotherapy in patients with relapsed or refractory intermediate and high-grade non-Hodgkin's lymphoma

This study was designed to assess the efficacy and safety of substituting cisplatin with oxaliplatin in the DHAP (dexamethasone, cytarabine and cisplatin) regimen for patients with relapsed or refractory non-Hodgkin's lymphoma. Twenty-four evaluable patients with intermediate or high-grade non-Hodgkin's lymphoma were treated at 3-weekly intervals with oxaliplatin (130 mg/m2, d 1), cytarabine (2 g/m2 for two doses, d 2) and dexamethasone (40 mg, d 1-4). The median age of the patients was 58 (range 18-70). Histological subtypes were diffuse large B cell, 20; mantle cell, two; anaplastic large cell, one; and peripheral T cell, one. The overall objective response rate (RR) was 50% [95% confidence interval (CI) = 29-71%] including four complete responses and eight partial responses. RR for those patients treated at first relapse was higher than those treated at second and subsequent relapse (77% versus 29%). Grade 3 and 4 toxicity was mainly haematological: anaemia 17%, neutropenia 75% and thrombocytopenia 75%. No grade 4 non-haematological toxicity was reported. No significant renal and neurotoxicity was demonstrated. Median survival was 10.6 months. Probabilities of 1-year progression-free survival and overall survival were 47% (95% CI = 26-66%) and 50% (95% CI = 23-72%) respectively. In conclusion, dexamethasone, cytarabine and oxaliplatin (DHAX) is a novel combination in salvage therapy for relapsed or refractory non-Hodgkin's lymphoma. It has clinically significant activity with an acceptable toxicity profile. Lack of renal toxicity makes DHAX an attractive cytoreductive regimen before high-dose chemotherapy.

Impact of surgery on survival in palliative patients with metastatic colorectal cancer after first line treatment with weekly 24-hour infusion of high-dose 5-fluorouracil and folinic acid

BACKGROUND

In palliative first-line treatment of colorectal cancer, the secondary resection of distant metastases after downstaging has constantly gained in importance. The objective of this prospective study was to examine the tumor response rate, the toxicity, the median survival time and the prognostic impact of metastatic resection after downstaging of consecutively enrolled patients with primary nonresectable colorectal cancer treated with once weekly 24-hour (24-h) infusion of high-dose 5-fluorouracil (5-FU) and folinic acid.

PATIENTS AND METHODS

Between January 1995 and July 1997, 53 consecutive patients with primary nonresectable metastases were recruited for a prospective phase II study. The patients received in out-patient care 500 mg/m2 folinic acid in the form of a 1-2-hour infusion followed by 2600 mg/m2 5-FU administered as a 24-h infusion once weekly. One treatment cycle comprised six weekly infusions followed by a two week rest. Three cycles were administered, and in the event of complete remission (CR) or partial remission (PR) and good tolerability, a fourth cycle was undertaken. Thereafter, the possibility of performing a curative metastatic resection was investigated.

RESULTS

Of the 53 patients treated, 7 showed a CR (13%), 15 patients a PR (28%), 26 patients stable disease (SD) (49%), and 5 patients progressive disease (PD) (10%). As the main symptom of toxicity, diarrhea (CTC grade 3 + 4) was observed in 11 patients (21%), followed by leucocytopenia (CTC grade 3 + 4) in 2 patients (4%), and the hand-foot syndrome in 1 patient (2%). The median survival time was 17 months with a median follow-up of 41 months (range: 28-59 months). In 9 patients (17%), a secondary metastatic resection was considered; in 6 patients (11%) curative resection was performed, and 4 patients (8%) showed no evidence of disease for at least three years.

CONCLUSION

In this phase II study, we have been able to show prospectively that, after downstaging by palliative treatment using a weekly 24-h infusion of high-dose 5-FU and folinic acid, secondary curative metastatic resection was technically feasible in 11% of the patients. For some of these patients, long-term survival is therefore possible. Secondary metastatic resection should be carried out in close interdisciplinary cooperation, and should be further investigated in prospective phase III studies.

Capecitabine and oxaliplatin in advanced colorectal cancer: a dose-finding study

PURPOSE

Capecitabine and oxaliplatin are both active anticancer agents in the treatment of patients with advanced colorectal cancer (ACRC). The aim of this dose-finding trial was to determine the maximum-tolerated dose (MTD), the dose-limiting toxicities (DLTs) and the activity of the combination in patients with advanced colorectal cancer.

PATIENTS AND METHODS

Twenty-five chemotherapy-pretreated patients received the combination of capecitabine and oxaliplatin. Capecitabine was administered orally twice a day continuously for 14 days in doses ranging from 1,650 to 2,500 mg/m2/d, and oxaliplatin was administered as a two-hour infusion on day 1 using dose, ranges from 100 to 130 mg/m2 repeated every three weeks.

RESULTS

Twenty-five patients were assessable for toxicity, and DLTs were diarrhea (grade > or = 3: 27%) and stomatitis (grade > or = 3: 9%) at dose level VI. Dose level V (capecitabine 2500 mg/m2 and oxaliplatin 120 mg/m2) was found to be the MTD. Hematological toxicity was minimal, overall neurotoxicity (grade 1-4) was 27% with 1% grade 3-4. A global response rate was 17% (95% confidence interval (95% CI): 2%-32%) and the median overall survival was 12 months.

CONCLUSION

The recommended dose for further phase II studies is capecitabine 2,500 mg/m2/d with intermittent schedule and oxaliplatin 120 mg/m2 every three weeks. The toxicities were mainly gastrointestinal: diarrhea, stomatitis and vomiting. This combination should be studied in phase II trials in advanced colorectal.

Management of chemotherapy-induced adverse effects in the treatment of colorectal cancer

The anticancer agents fluorouracil, raltitrexed, irinotecan and oxaliplatin show limited efficacy in the treatment of colorectal cancer and may be associated with substantial toxicity. Therefore, the prevention and reduction of chemotherapy-induced adverse effects is of major significance, in accordance with the increasing concern for the quality of life of patients with cancer. Therapeutic drug monitoring of fluorouracil and chronomodulation of fluorouracil and oxaliplatin, have been effective in reducing the incidence and gravity of adverse effects in several clinical trials. However, these concepts have not been implemented in clinical practice yet. At the present time, dose adaptation and supportive measures are the main tools for toxicity control in the treatment of colorectal cancer. In this review, supportive measures for alleviation of the adverse effects of fluorouracil, raltitrexed, irinotecan and oxaliplatin, respectively, are described, based on study results. The main adverse effects of these agents are myelosuppression, oral mucositis, diarrhoea, acute cholinergic syndrome, nausea and emesis, neurotoxicity, hand-foot syndrome and other cutaneous adverse effects, ocular toxicity, cardiotoxicity, small bowel toxicity, asthenia, elevated liver transaminase levels and alopecia. The incidence and gravity of these adverse effects are more or less related to the agent and administration schedule involved. The supportive measures and recommendations include the use of specific drugs, alterations of administration schedule and several nonpharmacological methods. In addition, guidelines for dosage adjustments when toxicity occurs are presented. For optimal management of adverse effects, patients should be considered individually, while patients, nurses and physicians should cooperate to identify and treat adverse effects in an early stage of their development.

Irinotecan plus oxaliplatin: a promising combination for advanced colorectal cancer

The standard treatment for advanced colorectal cancer (CRC) has been 5-fluorouracil (5-FU)-based chemotherapy. However, addition of irinotecan, a topoisomerase I inhibitor, to the combination of 5-FU and leucovorin (LV) has proven to be superior to treatment with 5-FU/LV alone in both chemonaive as well as previously treated patients. Oxaliplatin, a 1,2 diaminocyclohexane platinum compound, in combination with 5-FU and LV, has demonstrated superiority as first-line therapy over 5-FU and LV in terms of response rate and time to progression. The irinotecan/oxaliplatin combination showed synergistic activity in vitro, and the optimal dose safety profile has been explored in several phase I studies. Neutropenia and diarrhea were the dose-limiting toxicities. The recommended dose of irinotecan/oxaliplatin in every-2-week and every-3-week schedules ranged from 150-200 mg/m2 and 85 mg/m2, respectively. In the weekly schedule, the recommended doses of irinotecan/oxaliplatin were 65 mg/m2 and 60 mg/m2. Promising clinical efficacy in CRC was observed in all studies. A recent randomized phase II study revealed that the irinotecan/oxaliplatin combination has equivalent clinical activity to other 5-FU-based combinations and a manageable toxicity profile. The evaluation of irinotecan/oxaliplatin in phase III trials as well as in combination with 5-FU is ongoing.

Oxaliplatin and protracted venous infusion of 5-fluorouracil in patients with advanced or relapsed 5-fluorouracil pretreated colorectal cancer

The purpose of this study was to evaluate the activity and safety of oxaliplatin and protracted venous infusion of 5-fluorouracil (PVI 5-FU) in patients with advanced or relapsed 5-FU pretreated colorectal cancer. 38 patients with advanced or metastatic colorectal carcinoma with documented progression on or within 6 months following 5-FU or thymidylate synthase inhibitor containing chemotherapy were recruited between June 1997 and September 2000. Oxaliplatin (100 mg x m(-2)) was given every 2 weeks and PVI 5-FU (300 mg x m(-2) x day(-1)) was administered. Median age of patients was 61 years. 17 patients had >2 sites of disease involvement. 10 had received 5-FU based adjuvant chemotherapy. 16 received oxaliplatin and PVI 5-FU as second-line chemotherapy for advanced disease and 22 as third or subsequent lines. Median follow up was 6.1 months. The best achieved objective tumour response rate was 29% (11 partial responses 95% confidence interval [CI] = 15-46%). 20 patients (52.6%) had stable disease. The median duration of response was 3.9 months. Even for patients who had previously received both 5-FU and irinotecan (n = 22), 27.3% had partial response with oxaliplatin and PVI 5-FU. 37 patients had symptoms on entry into the study. 25 patients had pain, 10 had anorexia and 28 had lethargy. 64%, 70% and 17.9% had symptomatic improvement after treatment respectively. Grade 3-4 toxicities were anaemia 10.6%, neutropenia 2.6%, thrombocytopenia 5.2%, diarrhoea 18.9%, nausea and vomiting 2.7%, infection 5.4% and lethargy 37.8%. The median survival was 9.1 months. Probability of overall survival at 6 months was 58.4% (95% CI = 38.7-73.7%). The median failure-free survival was 4 months. Oxaliplatin and PVI 5FU is an active and well tolerated regimen in patients with heavily pre-treated advanced colorectal cancer.

Capecitabine in the management of colorectal cancer

Significant progress has been made in the chemotherapy of colorectal cancer. The author discusses new available options and the development of a new oral fluoropyrimidine, capecitabine (Xeloda). The rational development of this targeted drug with its selective activation in tumor tissue is highlighted. The clinical development of capecitabine and its present and future role in the management of colorectal cancer are reviewed.

Irinotecan and oxaliplatin: an overview of the novel chemotherapeutic options for the treatment of advanced colorectal cancer

Colorectal cancer is one of the most frequent malignancies in humans and an important cause of cancer death. Metastatic colorectal cancer remains incurable with available systemic therapeutic options. The most active cytotoxic drug against this malignancy, the antimetabolite 5-fluorouracil, was developed more than forty years ago, and as a single agent produces responses in only 10 to 15% of patients which in general last less than one year. Efforts to ameliorate these poor results resulted in the 5-fluorouracil/leucovorin combination, which enhances response rates about two-fold, without, however, significantly improving survival rates. The recent emergence of a handful of new 5-fluorouracil analogues and folate antagonists, as well as the topoisomerase I inhibitor irinotecan, and the third-generation platinum compound oxaliplatin, is likely to alter this gloomy scenario. These agents are at least as effective as 5-fluorouracil in patients with advanced colorectal carcinoma, both untreated and previously treated with 5-fluorouracil-based regimens. This has led to the approval of irinotecan as second-line treatment for 5-fluorouracil-refractory disease, while the use of oxaliplatin has been suggested for patients having a defective 5-fluorouracil catabolism. Recently, FDA approved the combination of irinotecan with 5-fluorouracil and leucovorin for first-line treatment of advanced colon cancer. Based on the synergistic preclinical antitumor effects of some of these agents, their meaningful single-agent activity, distinct mechanisms of cytotoxicity and resistance, and only partially overlapping toxicity profiles, effective combination regimens are now being developed, which are likely to lead to a new, more hopeful era for patients suffering from advanced colorectal carcinoma.

New drugs and combinations in the palliative treatment of colon and rectal cancer

Colorectal cancer (CRC) is a common disease. The overall survival has improved only marginally in recent decades despite advances in surgery and early detection. Potentially curative resection at disease presentation can be performed only in 70-80% of the patients, and overall survival at 5 years is less than 60%. Advanced disease is associated with a poor prognosis. Treatment for advanced colorectal cancer has nevertheless made progress in the last few years. Systemic chemotherapy doubles the survival of these patients compared to untreated controls. Chemotherapy has demonstrated effective palliation, improvement of quality of life (QoL) and symptom improvement in such patients. For nearly four decades, fluorouracil (5FU) has been the mainstay of treatment. New compounds active against colorectal cancer are now available. Several studies on this topic are ongoing.

Factors predicting efficacy of oxaliplatin in combination with 5-fluorouracil (5-FU) +/- folinic acid in a compassionate-use cohort of 481 5-FU-resistant advanced colorectal cancer patients

A statistical analysis was performed on the patient data collected from two compassionate-use programmes using oxaliplatin (Eloxatin(R)) + 5-fluorouracil (5-FU) +/- folinic acid (FA), to identify predictive factors for oxaliplatin-based salvage treatment in patients with 5-FU-resistant advanced colorectal cancer (ACRC). 481 5-FU-resistant ACRC patients, most with performance status < or = 2, > or = 3 involved sites, and > or = 2 prior lines of chemotherapy, received oxaliplatin + 5-FU +/- FA. Prognostic factors associated with overall response rate (ORR), time to progression (TTP) and overall survival (OS) were identified using univariate and multivariate logistic and/or Cox proportional hazards analyses. The ORR was 16% (95% CI: 13-20), the median TTP was 4.2 months (95% CI: 3.4-4.6), and the median OS was 9.6 months (95% CI: 8.6-10.6). The multivariate analysis indicated poor (> or = 2 WHO) performance status (PS), a large number of prior chemotherapy regimens (> or = 3), a low baseline haemoglobin level (< 10 g/dl), and a triweekly (vs biweekly) treatment administration schedule as significantly associated (P< 0.05) with a lower ORR. Sex (male), number of organs involved (> or =3) and alkaline phosphatase (AP) level (> or = 2 x the upper limit of normal) were associated (P< 0.05) with shorter TTP. Poor PS, a large number of organs involved, and elevated AP were independently and significantly correlated with shorter OS. Our analysis identified a relationship between efficacy results of oxaliplatin + 5-FU +/- FA treatment in 5-FU-resistant ACRC patients and baseline prognostic factors related to PS, extent of disease and number of prior regimens.

Review of the role of CPT-11 in the treatment of colorectal cancer

Colorectal cancer (CRC) is the second leading cause of cancer death in Western countries, and although the treatment of advanced CRC has progressed substantially, the improvements in response rates have not always been translated into a significant survival benefit. Until recently, the standard therapy for advanced CRC was a variety of biomodulated 5-fluorouracil (5-FU) regimens. 5-FU was used as first- or second-line therapy, and a different 5-FU regimen was used second line if first-line 5-FU therapy failed. Typically, the survival times for these patients were short and their quality of life poor. In recent years, a variety of new agents have emerged that have demonstrated activity in the treatment of advanced CRC. Of these, irinotecan (CPT-11) and oxaliplatin in combination with 5-FU and folinic acid (FA) have yielded the most promising results. However, only CPT-11 combined with either bolus or high-dose infusional 5-FU/FA, in randomized phase III studies, has demonstrated an increased response rate and median time to progression, producing a significant and clinically relevant survival advantage. In 2 randomized phase III studies, oxaliplatin/5-FU/FA demonstrated a clear increase in response rate over 5-FU/FA alone but failed to demonstrate a survival advantage. CPT-11 was approved by the Food and Drug Administration in April 2000 for the first-line treatment of advanced CRC in combination with 5-FU/FA.

New chemotherapy approaches in colorectal cancer

Colorectal cancer is one of the leading causes of cancer deaths in the Western world, with approximately 50% of all patients dying from metastatic disease. Until recently, therapeutic options for advanced colorectal cancer were mainly confined to chemotherapy with 5-fluorouracil in various schedules, with or without biochemical modulation with leucovorin. The development of new cytotoxic drugs with substantial activity in this tumor during the past 2 years has dramatically changed treatment strategies and therapeutic goals in metastatic colorectal cancer and has introduced neoadjuvant chemotherapy followed by secondary surgery with the intent of long-term survival. Among these new drugs, oral fluoropyrimidines (tegafur/uracil and capecitabine), irinotecan, and oxaliplatin have already established themselves as part of various treatment approaches. Other novel therapeutics including agents designed to act on molecular targets already show promising activity and will become part of combination protocols with current standard chemotherapy.

An overview of chemotherapy-induced peripheral sensory neuropathy, focusing on oxaliplatin

When treating patients for metastatic cancer, there is always a balance between the benefits of treatment and resulting side-effects. Peripheral sensory neuropathy (PSN) is a side-effect of many anticancer agents used in routine practice. Oxaliplatin is a relatively new agent currently licensed in over 50 countries including France, Germany and the UK for the treatment of metastatic colorectal cancer. Although it is a new agent, it is from the same family of drugs as cisplatin, an agent that has been used for many years. PSN is the most commonly discussed side-effect associated with oxaliplatin. Oxaliplatin-induced PSN is characterized by two distinct syndromes: a transient acute dysaesthesia and a cumulative distal neurotoxicity. Importantly, both are generally reversible after stopping treatment. Oxaliplatin-induced acute PSN is triggered and exacerbated by cold and can be greatly reduced in affected patients simply by avoiding cold conditions. Oxaliplatin-induced cumulative PSN may also be managed by temporary cessation of treatment.

Treatment of liver metastases from colorectal cancer: what is the best approach today?

Liver is the common site for metastases from colorectal cancer. The 5-year overall survival rate of patients following radical operations is 25%. Surgery can be carried out in only 10-15% of the patients, yet it remains the potential curative treatment for resectable lesions. For the unresectable cancers, only chemotherapy is recommended. New drugs such as Irinotecan prolongs the overall survival of patients affected by advanced disease. In patients with unresectable metastases at diagnosis, pre-surgical treatment with Oxaliplatin leads to reduction of the lesions, allowing resection in 16% of cases. Chemotherapy may be delivered directly into the liver via the hepatic artery. No, clinical trials, to date, have shown convincing survival results in patients treated with this procedure. Combined hepatic artery and systemic treatment may provide a new strategy as adjuvant therapy for patients undergoing resections.

A randomised phase II study of oxaliplatin alone versus oxaliplatin combined with 5-fluorouracil and folinic acid (Mayo Clinic regimen) in previously untreated metastatic colorectal cancer patients

The aim of this study was to examine the efficacy and safety of both oxaliplatin as a single agent and oxaliplatin in combination with dailyx5 bolus 5-fluorouracil and folinic acid (5-FU/FA, Mayo clinic regimen) in the first-line treatment of metastatic colorectal cancer (CRC) patients. 73 advanced CRC patients were randomised to receive either oxaliplatin 85 mg/m(2) every 2 weeks (35 patients), or the same treatment combined with 5-FU 425 mg/m(2)/day and FA 20 mg/m(2)/dayx5 days every 4 weeks (38 patients). Treatment was continued until disease progression or unacceptable toxicity. All patients had documented inoperable disease and no previous chemotherapy for advanced disease. Based on the investigators' assessment of best response, objective response rate was 9% (95% confidence interval (CI) 2-24%) in the oxaliplatin arm, and 45% (95% CI 27-64%) in the oxaliplatin+5-FU/FA arm. Median progression-free survival (PFS) was 2 months (95% CI 1.7-2.4 months) in the oxaliplatin arm and 3.9 months (95% CI 2.9-5 months) in the oxaliplatin+5-FU/FA arm. Severe neutropenia was seen in 23% of patients in the oxaliplatin+5-FU/FA arm, and none in the oxaliplatin arm. There were two treatment-related deaths, both in the oxaliplatin+5-FU/FA arm. In the oxaliplatin+5-FU/FA arm, severe diarrhoea, vomiting and stomatitis were seen in 34, 14 and 14% of the patients, respectively. In conclusion, oxaliplatin at a dose of 85 mg/m(2) given every 2 weeks was well tolerated and has limited activity in metastatic CRC, while the combination of this treatment with the full-dose Mayo clinic regimen (5-FU bolus 425 mg/m(2)/day+FA 20 mg/m(2)/dayx5 days every 4 weeks), although active, was unfeasible due to a high level of myelosuppression and gastrointestinal toxicity. Alternative lower dosing or other regimens are to be explored to ascertain the value of bolus 5-FU/FA combined with oxaliplatin.

Integrating the oral fluoropyrimidines into the management of advanced colorectal cancer

In colorectal cancer, leucovorin-modulated 5-fluorouracil (5-FU) has been the mainstay of both adjuvant treatment and treatment of metastatic disease for many years. In advanced disease, response rates of 10-43% are reported; efforts to improve efficacy through schedule modification, including prolonged infusions, have led to limited success. New agents with improved efficacy, tolerability and ease of administration are required. Among the newer drugs, irinotecan and oxaliplatin are becoming established as first- and second-line treatment for advanced disease. Their novel mechanisms of action have proven to be of value in 5-FU-resistant patients. In tandem with these developments, thymidylate synthase inhibition has remained an important objective and oral fluoropyrimidines such as capecitabine and UFT (uracil plus tegafur)/leucovorin have been developed with this goal in mind. Two large, phase III studies of capecitabine in metastatic disease demonstrated objective response rates of 26.6 and 24.8%. UFT/leucovorin has also been evaluated in phase III trials, with an 11.7% response rate reported. Both agents are being evaluated in combination with oxaliplatin and irinotecan, and ultimately oral fluoropyrimidines as monotherapy or combination therapy may replace intravenous (i.v.) 5-FU as first-line treatment for metastatic colorectal cancer.

New therapies, new directions: advances in the systemic treatment of metastatic colorectal cancer

Colorectal cancer is the second leading cause of cancer death and it is clear that patients with metastatic disease have better quality of life and survival when given treatment. Despite four decades of experience of treating patients with fluorouracil, there remains considerable controversy about the optimum dose and scheduling, as well as biomodulation with leucovorin and methotrexate. However, irrespective of the dose and schedule, overall survival times are poor--about 1 year. Disappointingly, oral agents with similar mechanisms to fluorouracil do not improve survival rates in comparison with fluorouracil and leucovorin treatment. Irinotecan and oxaliplatin are newer agents that have improved the response rates for patients with metastatic disease when they are added to flurouracil and leucovorin. The combination of irinotecan, fluorouracil, and leucovorin has also improved overall survival. These are small advances in the fight against colorectal cancer, and further drug development is necessary.

Phase I and pharmacokinetic study of hepatic arterial infusion with oxaliplatin in combination with folinic acid and 5-fluorouracil in patients with hepatic metastases from colorectal cancer

BACKGROUND

To determine dose-limiting toxicity (DLT), maximum tolerated dose (MTD), and pharmacokinetics (PK) of oxaliplatin administered as hepatic arterial infusion.

PATIENTS AND METHODS

Patients with isolated hepatic metastases from colorectal cancer were treated every three weeks with increasing doses of oxaliplatin (4 hours; starting dose 25 mg/m2, escalation in steps of 25 mg/m2) in combination with folinic acid (1 hour, 200 mg/m2) and 5-fluorouracil (2 hour, 600 mg/m2).

RESULTS

Twenty-one patients (median age, 61 years) have been entered all of whom are fully evaluable. The DLT has been observed at dose level 6, i.e., at 150 mg/m2/cycle and consisted of leucopenia, obliteration of the hepatic artery, and acute pancreatitis. Overall, toxicity mainly consisted of nausea/vomiting (16 of 21 patients), anemia (16 of 21), upper abdominal pain (15 of 21), sensory neuropathy (10 of 21), diarrhea (9 of 21), and thrombocytopenia (9 of 21). The mean PK parameters were: terminal half-life of ultrafiltrable platin, 17.75 +/- 9.29 hours; renal elimination, 48.7% +/- 14.1% of the applied dose; renal clearance 135.55 +/- 45.32 ml/min. The mean area under the plasma-concentration curve (AUC) increased linearly from 3.22 +/- 0.61 microg x h/ml to 18.45 +/- 8.90 microg x h/ml through the first five dose levels (P = 0.0004). Ten of eighteen evaluable patients achieved a complete or partial response (59%).

CONCLUSIONS

The recommended dose for phase II studies is 125 mg/m2 oxaliplatin.

Circadian chronotherapy for human cancers

Cell physiology is regulated by a 24-hour clock, consisting of interconnected molecular loops, involving at least nine genes. The cellular clock is coordinated by the suprachiasmatic nucleus, a hypothalamic pacemaker which also helps the organism to adjust to environmental cycles. This circadian organisation brings about predictable changes in the body's tolerance and tumour responsiveness to anticancer agents, and possibly also for cancer promotion or growth. The clinical relevance of the chronotherapy principle, ie treatment regimens based upon circadian rhythms, has been demonstrated in randomised, multicentre trials. Chronotherapeutic schedules have been used to document the safety and activity of oxaliplatin against metastatic colorectal cancer and have formed the basis for a new approach to the medicosurgical management of this disease, which achieved unprecedented long-term survival. The chronotherapy concept offers further promise for improving current cancer-treatment options, as well as for optimising the development of new anticancer or supportive agents.

Advances in the treatment of metastatic colorectal cancer

Colorectal cancer represents the third leading cause of cancer mortality in the United States. During the past four decades, 5-fluorouracil (5-FU) has served as the cornerstone of therapy for individuals with advanced colorectal cancer (ACRC). Despite numerous attempts at maximizing efficacy of 5-FU through biochemical modulation, a significant benefit in terms of survival has never been realized. The recent emergence of novel chemotherapeutic drugs employing different mechanisms of action than 5-FU has led to the incorporation of irinotecan (CPT-11) with 5-FU/leucovorin as the new standard first-line regimen for future trials. This review outlines emerging data utilizing oral fluoropyrimidines and other new agents including oxaliplatin, raltitrexed, and eniluracil. Randomized clinical trials are currently underway in an effort to define optimal combination chemotherapy regimens, scheduling of agents, duration of therapy, and choice of therapy using a variety of prognostic molecular markers.

Fluorouracil modulation in colorectal cancer: lack of improvement with N -phosphonoacetyl- l -aspartic acid or oral leucovorin or interferon, but enhanced therapeutic index with weekly 24-hour infusion schedule--an Eastern Cooperative Oncology Group/Cancer and Leukemia Group B Study

PURPOSE

To investigate mechanism-directed regimens in maximizing the efficacy of fluorouracil (5-FU) in advanced colorected cancer.

PATIENTS AND METHODS

Based on promising phase II data, a randomized comparison of various methods for the biochemical modulation of 5-FU was undertaken in patients with advanced colorectal cancer. The control group received single-agent 5-FU as a 24-hour infusion weekly. Patients (N = 1,120) with no prior chemotherapy for metastatic disease were randomized to one of the following arms: arm A, 5-FU 2,600 mg/m2 by 24-hour infusion, weekly; arm B, N-phosphonoacetyl-l-aspartic acid 250 mg/m2 day l, 5-FU 2,600 mg/m2 by 24-hour infusion day 2, weekly; arm C, 5-FU 600 mg/m2 with oral leucovorin (LV) 125 mg/m2 hourly for the preceding 4 hours, weekly; arm D, 5-FU 600 mg/m2 with intravenous (IV) LV 600 mg/m2, weekly; arm E, 5-FU 750 mg/m2/d IV by continuous infusion for 5 days, then 750 mg/m2 weekly, and recombinant interferon alfa-2a 9 million units subcutaneously three times weekly. Median follow-up was 4.8 years.

RESULTS

Of the 1,098 assessable patients, 57% had measurable disease. The toxicity of all the regimens was tolerable. Grade 4 or worse toxicity occurred in 11%, 11%, 30%, 24%, and 22% on each arm, respectively; diarrhea was the most common adverse effect. These toxicity patterns favored significantly (P <.001) the 24-hour infusion arms. Median survival (months) by arm was A, 14.8; B, 11.9; C, 13.5; D, 13.6; and E, 15.2. These survival durations did not differ significantly.

CONCLUSION

We conclude that a weekly infusion regimen of 5-FU is significantly less toxic than and as effective as 5-FU bolus regimens modulated by either LV or interferon in patients with metastatic colorectal cancer.

Comparison of oral capecitabine versus intravenous fluorouracil plus leucovorin as first-line treatment in 605 patients with metastatic colorectal cancer: results of a randomized phase III study

PURPOSE

To compare the response rate, efficacy parameters, and toxicity profile of oral capecitabine with bolus intravenous (IV) fluorouracil plus leucovorin (5-FU/LV) as first-line treatment in patients with metastatic colorectal cancer.

PATIENTS AND METHODS

We prospectively randomized 605 patients to treatment with oral capecitabine for 14 days every 3 weeks or 5-FU/LV by rapid IV injection daily for 5 days in 4-week cycles.

RESULTS

The overall objective tumor response rate among all randomized patients was significantly higher in the capecitabine group (24.8%) than in the 5-FU/LV group (15.5%; P =.005). In the capecitabine and 5-FU/LV groups, median times to disease progression were 4.3 and 4.7 months (log-rank P =.72), median times to treatment failure were 4.1 and 3.1 months (P =.19), and median overall survival times were 12.5 and 13.3 months (P =.974), respectively. Capecitabine, compared with bolus 5-FU/LV treatment, produced a significantly lower incidence (P <.0002) of diarrhea, stomatitis, nausea, and alopecia. Patients treated with capecitabine also displayed lower incidences of grade 3/4 stomatitis and grade 3/4 neutropenia (P <.0001) leading to significantly less neutropenic fever/sepsis. Grade 3 hand-foot syndrome (P <.00001) and grade 3/4 hyperbilirubinemia were the only toxicities more frequently associated with capecitabine than with 5-FU/LV treatment.

CONCLUSION

Oral capecitabine was more active than 5-FU/LV in the induction of objective tumor responses. Time to disease progression and survival were at least equivalent for capecitabine compared with the 5-FU/LV arm. Capecitabine also demonstrated clinically meaningful benefits over bolus 5-FU/LV in terms of tolerability.

Chemotherapy in elderly patients with colorectal cancer

BACKGROUND

Colorectal cancer is usually diagnosed in patients around 70 years of age. With a continuous increase in life expectancy we may expect a higher number of elderly patients in the future. Because patients above 70 or 75 years are often excluded there is uncertainty as to what extent systemic adjuvant and palliative treatment should be offered to elderly patients.

METHODS

We reviewed the available literature on adjuvant and metastatic colorectal cancer in order to identify reports on elderly patients treated within chemotherapy trials.

RESULTS

Only about 20% of patients entering clinical trials belong to the age group of over 70 years and represent the minority of the very fit patients. Compared to their younger counterparts 5-FU-based treatment appears to be equally effective and more toxic according to some reports. Data regarding raltitrexed, oral fluoropyrimidines, topoisomerase I inhibitors or DACH-platin derivates are limited but suggest no age-specific differences in activity or toxicity.

CONCLUSIONS

Elderly patients should not be excluded from clinical trials and studies in unfit elderly patients are warranted. Elderly patients need more attention regarding their functional, social and mental status. Fit elderly patients should be offered adjuvant or palliative chemotherapy.

Oxaliplatin plus raltitrexed in patients with advanced colorectal carcinoma: results of a Phase I-II trial

BACKGROUND

Oxaliplatin and raltitrexed both are active anticancer agents in the treatment of patients with advanced colorectal carcinoma: They have different mechanisms of action and toxicity profiles and have shown at least additive effects in experimental and preliminary clinical studies. The aim of this disease oriented Phase I-II study was to determine the maximum tolerated dose (MTD), the dose-limiting toxicities (DLT), and the objective response rate of this combination in patients with advanced colorectal carcinoma.

METHODS

Between April 1998 and March 1999, 69 patients with measurable metastatic colorectal carcinoma who previously were unexposed to palliative chemotherapy were enrolled. In the Phase I part of the study, 27 patients were treated with 3-weekly courses of a fixed dose of raltitrexed (3 mg/m(2) given as a 15-minute intravenous infusion) followed by a 2-hour infusion of oxaliplatin, which was escalated in consecutive cohorts of three to six patients from 85 mg/m(2) to 100 mg/m(2), 120 mg/m(2), 130 mg/m(2), and 140 mg/m(2). After having defined the toxic dose, 42 additional patients were entered at one dose level below to define the therapeutic index of this combination more precisely.

RESULTS

In the Phase I part of the study, during the first three dose levels, only one patient each experienced DLT (Grade 3 increase in transaminases, diarrhea, and stomatitis); at level 4, two of the first six patients entered had Grade 3 neutropenic infection or peripheral neurotoxicity, whereas dose level 5 (oxaliplatin 140 mg/m(2)) constituted the toxic dose with three of three patients experiencing DLT (Grade 3 asthenia, transient amaurosis, and diarrhea with Grade 4 neutropenia). Externally reviewed objective responses were noted in 9 of these 27 patients (33%), and stable disease occurred in 12 patients (44.4%). Among the 42 patients who were treated subsequently at the MTD level (Phase II portion), 20 patients (47.6%) responded (95% confidence interval, 32-62.6%), and 21 patients (50%) had stable disease. Their median progression free survival was 9.0 months, and the median overall survival, with 42 patients (67%) currently alive, is > 14.5 months. Treatment tolerance at the MTD was acceptable, with only 9 of 42 patients (21%) experiencing Grade 3-4 neutropenia; Grade 3 nonhematologic adverse reactions included increase in serum transaminases in 6 patients, peripheral neuropathy in 3 patients, diarrhea in 3 patients, and both stomatitis and emesis in only 1 patient each.

CONCLUSIONS

The described objective response and toxicity data, which are in agreement with preliminary results of other Phase I-II studies, support the promising therapeutic potential of this combination in the treatment of patients with advanced colorectal carcinoma. Due to its substantial antitumor activity, tolerance (at the recommended MTD level), and convenient 3-weekly outpatient administration schedule, further evaluation of this regimen seems warranted.

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.

5-fluorouracil modulated by leucovorin, methotrexate and mitomycin: highly effective, low-cost chemotherapy for advanced colorectal cancer

We have reported that an alternating regimen of bolus and continuous infusion 5-fluorouracil (FU) was superior to bolus FU in terms of response rate and progression-free survival in advanced colorectal cancer. Biochemical modulation was an essential part of this regimen and it was selective for the schedule of FU administration: bolus FU was in fact modulated by methotrexate (MTX) while continuous infusion FU was potentiated by 6-s-leucovorin (LV). Considering the low cost and the favourable report on the activity of mitomycin C (mito) added to CI FU, we have incorporated this agent in the infusional part of our treatment programme. 105 patients with untreated, advanced, measurable colorectal cancer were accrued from 13 Italian centres and treated with the following regimen. 2 biweekly cycles of FU bolus (600 mg/m(2)), modulated by MTX (24 h earlier, 200 mg/m(2)) were alternated with a 3-week continuous infusion of FU (200 mg/m(2)daily), modulated by LV (20 mg/m(2)weekly bolus). Mito, 7 mg/m(2), was given on the first day of the infusional period. After a 1 week rest, the whole cycle (8 weeks) was repeated, if indicated. 5 complete and 34 partial responses were obtained (response rate, 37% on the intention to treat basis; 95% confidence limits, 28-46%). After a median follow-up time of 26 months, 37 patients are still alive. The median progression-free survival is 7.7 months with an overall survival of 18.8 months and a 2-year survival rate of 30%. The regimen was very well tolerated with fewer than 13% of patients experiencing WHO grade III-IV toxicity. These results are consistent with those obtained by our group in 3 previous trials of schedule specific biochemical modulation of FU. They also indicate a highly active, little toxic, inexpensive regimen of old drugs to be used (a) as an alternative to the more expensive combinations including CPT-11 or oxaliplatin or (b) as the basis for combination programmes with these agents.

Colorectal cancer and metastasectomy: treatment of advanced disease

Systemic therapy of advanced colorectal cancer has become a well established and widely accepted approach for advanced colorectal cancer. The results of prospective randomised trials have demonstrated that first and second line chemotherapy improves the outcome compared with best supportive care. With modern chemotherapy concepts, objective response rates of 30-50% and median survival times of 14-17 months can be achieved which is a step ahead in the management of this disease. Moreover, first experiences with 'preoperative' chemotherapy in technically or prognostically not curatively resectable metastases indicate that active chemotherapy regimens may offer a chance for cure in some subsets of patients with liver metastases. It is still a matter of debate whether combination chemotherapy should be used upfront in all patients or whether the same outcome can be achieved with the sequential use of the available drugs. Ongoing and planned trials dedicated to these issues (preoperative therapy, sequential or combination chemotherapy, etc.) will hopefully contribute to a more differentiated and individualised use of the available treatment options.

Oxaliplatin: a new agent for colorectal cancer

For nearly 40 years, the medical treatment of colorectal cancer had been limited to the fluoropyrimidines until the recent development of irinotecan (CPT-11). In the past decade, a new agent has appeared, oxaliplatin. This third-generation platinum compound has synergistic activity with 5-fluorouracil and is non-cross-resistant with 5-fluorouracil, CPT-11, and other platinum agents. Numerous clinical trials in Europe have demonstrated the activity of oxaliplatin in patients with untreated and refractory metastatic colorectal cancer. Nevertheless, the US Food and Drug Administration recently denied approval for oxaliplatin as first-line treatment of colorectal cancer because of a lack of clear-cut survival advantage in clinical trials. Additional clinical trials in patients with colorectal cancer are ongoing in the United States and will test the activity of oxaliplatin in the metastatic and adjuvant setting. These studies will define the role for what appears to be a very useful and important agent.

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.

Phase II study of liposomal doxorubicin in patients with advanced colorectal cancer

Doxil is a liposomal preparation of doxorubicin that results in prolonged pharmacologic exposure in vivo to the active agent. We sought to test the hypothesis that this new formulation would result in improved efficacy in patients with colorectal cancer. Patients with advanced colorectal cancer who had received prior therapy were eligible for the trial. Treatment consisted of Doxil 45 mg/m2 intravenously every 3 weeks. Seventeen patients entered the trial and they received a median of two cycles of treatment. None of the patients had a partial response to treatment. Stable disease was the best response, and one patient received therapy for 17 cycles before her disease progressed. The therapy was well tolerated, with only two patients having the dose decreased because of hand-foot syndrome. Four patients experienced allergic reactions during the infusion, but with appropriate premedication and slowing of the infusion, treatment was able to be resumed without difficulty. No greater than grade I neutropenia or thrombocytopenia developed in any patient. Although Doxil was well tolerated at this dose and schedule, it was not an active agent in this group of patients. Doxil alone or in combination with other agents is worthy of further study in cancers responsive to doxorubicin.