Capecitabine plus oxaliplatin for the treatment of colorectal cancer

Based on improved safety and efficacy results, advanced colorectal cancer (CRC) treatment has recently shifted from intravenous bolus 5-fluorouracil (5-FU) monotherapy to standard combinations of prolonged intravenous 5-FU infusion with either oxaliplatin (FOLFOX) or irinotecan (FOLFIRI). Capecitabine, a rationally designed oral fluoropyrimidine that is converted into 5-FU preferentially at the tumor site, could replace infusional 5-FU as the mainstay of combined chemotherapy treatment for metastatic CRC. Evidently, oral medication obviates the drawbacks of prolonged intravenous infusion. The combination of capecitabine and oxaliplatin is especially attractive owing to its favorable tolerability profile, good activity and convenient administration schedule. Phase III trials comparing capecitabine/oxaliplatin with infusional regimens of 5-FU +/- LV and oxaliplatin in advanced CRC show similar toxicity and efficacy outcomes with both regimens. Capecitabine has the potential to replace 5-FU/LV as the optimal combination partner for oxaliplatin at a higher cost. Capecitabine and oxaliplatin concomitantly with radiation therapy has been evaluated before surgery in rectal cancer treatment. The combination of capecitabine and oxaliplatin, with or without bevacizumab, a monoclonal antibody blocking VEGF, is also being evaluated in early stage colon cancer.     

Oral capecitabine: bridging the Atlantic divide in colon cancer treatment

5-Fluorouracil (5-FU) plus leucovorin (LV) has been the mainstay of treatment for colorectal cancer (CRC), with infused schedules more widely adopted in Europe and bolus schedules preferred in North America. However, the effective, oral fluoropyrimidine capecitabine is increasingly replacing intravenous (IV) 5-FU/LV on both sides of the Atlantic. Capecitabine generates 5-FU preferentially in tumor and is a well-established, first-line treatment for metastatic CRC. In this setting, capecitabine achieves a superior response rate, at least equivalent time to disease progression (TTP) and overall survival, and favorable safety compared with bolus 5-FU/LV. The benefits of capecitabine have been transfered into the adjuvant setting. Recent data from a large, international, randomized trial (Xeloda Adjuvant Chemotherapy Trial [X-ACT]) confirm that capecitabine (Xeloda, Roche Laboratories, Nutley, NJ) achieves favorable safety versus 5-FU/LV (Mayo Clinic regimen) and is at least as effective as IV 5-FU/LV in the adjuvant treatment of patients with resected stage III colon cancer. Capecitabine is also an effective and well-tolerated combination partner for oxaliplatin (XELOX) and irinotecan (XELIRI), achieving high efficacy with a good safety profile. An extensive phase III clinical trial program is further establishing the potential of the simplified capecitabine combinations to improve outcomes and unify treatment practices in the metastatic and adjuvant settings. New combinations with novel agents such as capecitabine/oxaliplatin plus erlotinib or bevacizumab are currently under investigation. Capecitabine has also shown promising activity and good tolerability in combination with radiotherapy in rectal cancer.     

Mortality associated with daily bolus 5-fluorouracil/leucovorin administered in combination with either irinotecan or oxaliplatin: results from Intergroup Trial N9741

BACKGROUND: Intergroup Trial N9741 evaluated 5-fluorouracil (5-FU)/leucovorin (LV) administered in conjunction with either irinotecan or oxaliplatin in the first-line treatment of advanced colorectal carcinoma (CRC). The current report describes two treatment arms that were withdrawn from the protocol due to unexpected treatment-related toxicities and a high mortality rate. The complications observed in these arms highlight the importance of aggressive and immediate supportive care in the management of digestive toxicity. METHODS: In Trial N9741, patients were randomly assigned to receive one of the following six regimens: 1) irinotecan plus bolus 5-FU/LV (Arm A); 2) sequential irinotecan plus bolus 5-FU/LV (Arm B); 3) bolus 5-FU/LV only (Mayo Clinic regimen; Arm D); 4) oxaliplatin plus bolus 5-FU/LV (Arm E); 5) oxaliplatin plus infusional 5-FU/LV (Arm F); or 6) oxaliplatin plus irinotecan (Arm G). In the current study, the authors investigated treatment-related toxicity in patients who received either of the two combination regimens containing daily bolus 5-FU (i.e., patients in Arm B or Arm E). RESULTS: Sixty-one and 47 patients were enrolled in Arm B and Arm E, respectively. Diarrhea and neutropenia were the most common toxicities in both groups. Five patients in Arm B (8.2%) and 4 patients in Arm E (8.5%) died within 60 days of study entry. All fatal toxicities occurred within 15 days of treatment administration, and all deaths were associated with the simultaneous occurrence of multiple symptoms, which were dominated by Grade > or = 3 diarrhea. CONCLUSIONS: Combination regimens containing daily bolus 5-FU/LV and oxaliplatin or irinotecan can be associated with severe gastrointestinal toxicity and high mortality rates. Therefore, the authors recommend the use of more tolerable infusional 5-FU-based regimens in the treatment of metastatic CRC.     

Capecitabine versus 5-fluorouracil in colorectal cancer: where are we now?

Fluorouracil (5-FU) remains the most widely used agent for colorectal cancer. Capecitabine is a rationally designed 5-FU pro-drug developed to mimic the continuous infusion of 5-FU while avoiding complications and inconvenience of intravenous administration. Capecitabine is absorbed intact from the gastrointestinal tract, converted enzymatically to active 5-FU, and released directly into the tumor. Capecitabine’s efficacy and safety are shown in multiple phase III trials across different disease stages and therapy lines. Three randomized phase III trials demonstrated the equivalence of capecitabine plus oxaliplatin (XELOX) versus 5-FU/leucovorin (LV)/oxaliplatin (FOLFOX). The safety of capecitabine compared with 5-FU depends on the regimen of 5-FU used. The adverse event rate with oxaliplatin in combination with infusional 5-FU is similar to that of capecitabine plus oxaliplatin but is associated with more neutropenia and venous thrombotic events; capecitabine plus oxaliplatin-based regimens tend to be associated with more grade 3 diarrhea and hand-foot skin reaction. Combination therapy with capecitabine and irinotecan (CapeIRI) versus 5-FU/LV and irinotecan (FOLFIRI) had more variable results; some former schedules resulted in excessive treatment-related toxicity. More recent data show that lower capecitabine and irinotecan doses, different schedules, and combination with targeted agents (e.g, bevacizumab) have resulted in more favorable outcomes.     

Randomised study of sequential versus combination chemotherapy with capecitabine, irinotecan and oxaliplatin in advanced colorectal cancer, an interim safety analysis. A Dutch Colorectal Cancer Group (DCCG) phase III study.

BACKGROUND: Results on overall survival in randomised studies of mono- versus combination chemotherapy in advanced colorectal cancer patients may have been biased by an imbalance in salvage treatments. This is the first randomised study that evaluates sequential versus combination chemotherapy with a fluoropyrimidine, irinotecan and oxaliplatin. PATIENTS AND METHODS: A total of 820 patients were randomised between first-line capecitabine, second-line irinotecan and third-line capecitabine + oxaliplatin (arm A) versus first-line capecitabine + irinotecan, and second-line capecitabine + oxaliplatin (arm B). The primary end point was overall survival. We present the results of an interim analysis on the safety data in the first 400 patients. RESULTS: In first-line the incidence of grade 3-4 diarrhoea, nausea, vomiting and febrile neutropenia was significantly higher in arm B. However, when toxicity over all lines was considered only grade 3 hand-foot syndrome occurred more frequently in arm A (12% versus 6%, respectively, P = 0.041). The incidence of cardiovascular toxicity was low. In two out of five patients with sudden death (one in arm A, four in arm B) cardiovascular risk factors were present. CONCLUSIONS: Both treatment arms had an acceptable safety profile. These data imply that the results on survival will be the major determinant for the selection of either strategy. Capecitabine plus irinotecan appears to be a feasible first-line treatment for patients with advanced colorectal carcinoma.     

Oxaliplatin plus oral fluoropyrimidines in colorectal cancer

The medical treatment of colorectal cancer (CRC) has rapidly evolved in recent years with the introduction of novel cytotoxic drugs into clinical practice such as irinotecan, oxaliplatin, and capecitabine. Combination regimens using infusional 5-fluorouracil (5-FU)/leucovorin (LV) plus either oxaliplatin or irinotecan have demonstrated clinically meaningful, high efficacy in advanced CRC. Based on the results of the Intergroup trial N9741, FOLFOX4, a combination of infusional plus bolus 5-FU/LV and oxaliplatin, has emerged as the standard first-line therapy in the palliative setting. However, infusional 5-FU-based regimens carry the need for use of central venous lines and implantable ports to allow treatment on an outpatient basis and are thus inconvenient and expensive. The use of oral fluoropyrimidines (capecitabine or uracil/tegafur [UFT] plus LV) as substitutes for infusional 5-FU in combination protocols with oxaliplatin offers greater convenience, at the same time conceivably maintaining the high efficacy and tolerability observed with intravenous protocols. Various phase I/II trials have recently been reported that investigated oxaliplatin in combination with either capecitabine or UFT/LV in patients with advanced CRC. This review will detail the results of these trials focused on capecitabine-based combinations.     

Oral capecitabine compared with intravenous fluorouracil plus leucovorin in patients with metastatic colorectal cancer: results of a large phase III study.

PURPOSE: To compare the efficacy and safety of orally administered capecitabine (Xeloda; Roche Laboratories, Inc, Nutley, NJ), a novel fluoropyrimidine carbamate designed to mimic continuous fluorouracil (5-FU) infusion but with preferential activation at the tumor site, with that of intravenous (IV) 5-FU plus leucovorin (5-FU/LV) as first-line treatment for metastatic colorectal cancer. PATIENTS AND METHODS: We prospectively randomized 602 patients to treatment with capecitabine 1,250 mg/m(2) administered twice daily days 1 to 14 every 3 weeks, or to the 4-weekly Mayo Clinic regimen (5-FU/LV) until disease progression or unacceptable toxicity. RESULTS: The primary objective, to demonstrate at least equivalent response rates in the two treatment groups, was met. The overall response rate was 18.9% for capecitabine and 15.0% for 5-FU/LV. In the capecitabine and 5-FU/LV groups, respectively, median time to disease progression was 5.2 and 4.7 months (log-rank P =.65); median time to treatment failure was 4.2 and 4.0 months (log-rank P =.89); and median overall survival was 13.2 and 12.1 months (log-rank P =.33). The toxicity profiles of both treatments were typical of fluoropyrimidines. However, capecitabine led to significantly lower incidences (P <.00001) of stomatitis and alopecia, but a higher incidence of cutaneous hand-foot syndrome (P <.00001). Capecitabine also resulted in lower incidences (P <.00001) of grade 3/4 stomatitis and neutropenia, leading to a lower incidence of grade 3/4 neutropenic fever and sepsis. Only grade 3 hand-foot syndrome (P <.00001) and uncomplicated grade 3/4 hyperbilirubinemia (P <.0001) were reported more frequently with capecitabine. CONCLUSION: Oral capecitabine achieved an at least equivalent efficacy compared with IV 5-FU/LV. Capecitabine demonstrated clinically meaningful safety advantages and the convenience of an oral agent.     

Drug Insight: Metastatic colorectal cancer--oral fluoropyrimidines and new perspectives in the adjuvant setting

Capecitabine and uracil/ftorafur (UFT) are prodrugs of 5-fluorouracil (5-FU) that can be administered orally. Both drugs have been shown to be as effective as bolus 5-FU and folinic acid (FA), both as adjuvant treatment, and for the treatment of metastatic colorectal cancer. However, as the addition of oxaliplatin to 5-FU has been shown to improve disease-free survival in adjuvant therapy, oxaliplatin/5-FU is currently regarded as the standard adjuvant treatment, rather than fluoropyrimidine monotherapy. For the treatment of metastatic colorectal cancer, improved response rates and prolonged survival have been reported when irinotecan or oxaliplatin was added to 5-FU/FA; a further increase in efficacy was shown when bevacizumab, an antibody to vascular endothelial growth factor, was added to chemotherapy. Studies investigating the substitution of infusional 5-FU with oral compounds in combination therapy (e.g. FOLFOX versus capecitabine/oxaliplatin) are ongoing, but preliminary results in metastatic patients advise caution because of increased toxicity when used with irinotecan, and statistically non-significant trends of a decreased efficacy when used with oxaliplatin. Therefore, the combined use of oral 5-FU prodrugs plus irinotecan or oxaliplatin is not recommended at present. Oral 5-FU prodrugs, however, offer a convenient and less toxic treatment option in adjuvant treatment and in the treatment of advanced colorectal carcinoma in patients who do not want an intensified regimen, those that have contraindications for implanted venous access devices, and those who are not candidates for a combination therapy with irinotecan and oxaliplatin.     

A phase II study of capecitabine plus oxaliplatin (XELOX)

Background: Capecitabine and oxaliplatin are both effective and well-tolerated monotherapies for the treatment of advanced colorectal cancer (CRC). Oxaliplatin has also been shown to be very effective when combined with 5-FU/LV in the first-line setting. Aim of the Study: Assess the efficacy and safety of capecitabine plus oxaliplatin (XELOX) in patients with previously untreated advanced CRC. Methods: Fifty-three patients with measurable disease received capecitabine 1,000 mg/m² twice daily on d 1–14 and oxaliplatin 130 mg/m² on d 1, every 3 wk. Of these, 52 were evaluable for safety and 49 for antitumor response. Results: There was a low rate of grade 1/2 adverse events; grade 3/4 events included leukopenia (10%), neutropenia (6%), thrombocytopenia (2%), nausea/vomiting (4%), and diarrhea (4%). The overall response rate was 39% (95% CI, 25–54%) and median time to disease progression was 7.8 mo. Conclusions: XELOX is an active and well-tolerated first-line treatment for advanced CRC. Randomized phase III studies are ongoing to compare XELOX with FOLFOX in view of the comparable efficacy and safety but superior convenience of XELOX therapy.     

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.     

Optimizing the use of irinotecan in colorectal cancer

The introduction of new agents with novel mechanisms of action has led to considerable changes in the management of colorectal cancer in recent years. One of these novel agents, irinotecan, has been shown to offer survival benefits in both the first- and second-line treatment of advanced/metastatic colorectal cancer. Irinotecan monotherapy improves survival compared with both best supportive care and infused 5-fluorouracil (5-FU) in patients with 5-FU-pretreated disease, without impacting negatively on patients' quality of life. As a result, irinotecan monotherapy is now considered to be the standard treatment in this setting. Irinotecan in combination with 5-FU/leucovorin (LV) was subsequently evaluated as first-line therapy for metastatic colorectal cancer in two randomized, phase III studies. Both trials confirmed that irinotecan plus infused or bolus 5-FU/leucovorin LV provide a modest survival benefit without compromising patients' quality of life. Combined irinotecan/5-FU/LV represents a new standard in the first-line treatment of metastatic colorectal cancer. In an attempt to further improve efficacy and tolerability, recent studies have investigated irinotecan in combination with capecitabine as first-line treatment for colorectal cancer. The replacement of infused 5-FU with oral capecitabine provides a more convenient treatment option. A phase I study was conducted to establish the maximum tolerated dose, and demonstrated encouraging antitumor activity and a manageable safety profile with the combination. This article provides a brief overview of the pivotal clinical trial data for irinotecan and discusses how irinotecan-based therapy may be improved in the future. It also discusses potential optimization of irinotecan use through identification of patient subpopulations most likely to benefit from combination or sequential strategies, and the potential of new, oral agents such as capecitabine to replace i.v. 5-FU as a combination partner for irinotecan.     

Novel chemotherapy agents for colorectal cancer: Oral fluoropyrimidines, oxaliplatin, and raltitrexed

Agents now under investigation for treatment of advanced colorectal cancer (CRC) include the oral fluoropyrimidines, oxaliplatin, and raltitrexed. Research efforts directed at finding agents that conveniently and effectively deliver 5-fluorouracil (5-FU) in a protracted fashion have led to the development of several oral fluoropyrimidines. These agents, which include capecitabine; tegafur and uracil plus leucovorin (UFT/LV); eniluracil plus oral 5-FU; and S-1, are convenient and less toxic than intravenous bolus 5-FU. Oxaliplatin has a uniquely different mechanism of action compared with that of 5-FU and has demonstrated activity not only in the first-line treatment setting but also in patients whose disease has progressed during or following 5-FU treatment. In the first-line setting, when oxaliplatin is combined with 5-FU plus LV, response rates and time to disease progression are remarkably improved compared with 5-FU/LV alone. Raltitrexed, a unique thymidylate synthase inhibitor, has undergone extensive phase III evaluation in CRC. The advent of these novel agents has led to development of combined chemotherapy regimens now being introduced into the adjuvant setting.     

Treatment of colorectal cancer metastasis: The role of chemotherapy

5-Fluorouracil (5-FU) has been the main chemotherapeutic agent for the treatment of colorectal cancer for four decades with modest efficacy. Modulation of 5-FU by leucovorin or continuous infusion improves the response rate, but overall survival duration remains approximately 12 months. Many oral fluoropyrimidines have been studied, including capecitabine, UFT, S-1, and Eniluracil. Capecitabine has demonstrated equivalent efficacy with 5-FU and has been approved as first line treatment. The combinations of capecitabine with CPT-11 or oxaliplatin are being developed. CPT-11 demonstrated non-crossover resistance with 5-FU and was proven to be effective treatment for patients who received prior 5-FU. CPT-11 in combination with 5-FU has demonstrated improved response rate and overall survival duration over 5-FU or CPT-11. Oxaliplatin plus 5-FU has offered another effective treatment option for colorectal cancer. Both 5-FU plus leucovorin in combination with CPT-11 or oxaliplatin are widely used first-line chemotherapies for advanced colorectal cancer. Optimal combinations and sequences of treatment are being studied, since several effective regimens have become available.     

New systemic frontline treatment for metastatic colorectal carcinoma

Options for first-line chemotherapy in patients with metastatic colorectal carcinoma have broadened considerably with the introduction of irinotecan and oxaliplatin. Furthermore, the oral fluoropyrimidine capecitabine has demonstrated efficacy in Phase III trials and recently was approved for first-line treatment in Europe and the United States. Capecitabine yielded similar median times to disease progression and median survival rates compared with bolus 5-fluorouracil (5-FU)/leucovorin (LV) (Mayo Clinic/North Central Cancer Treatment Group regimen), with superior and similar response rates, respectively. However, its role as a first-line, single-agent substitute for intermittent infusional 5-FU/LV remains to be defined. The addition of irinotecan or oxaliplatin to 5-FU/LV resulted in improved response rates and progression-free survival in large, randomized trials; moreover, irinotecan-containing regimens resulted in improved overall survival. Prevalent regimens of irinotecan/5-FU/LV and oxaliplatin/5-FU/LV have been compared in two randomized Phase III trials. One study demonstrated the statistical superiority of oxaliplatin/infusional 5-FU/LV over irinotecan/bolus 5-FU/LV in terms of response, time to disease progression, and median survival; however, those advantages may have been attributable to infusional administration or to major differences in second-line therapy. A randomized Phase III study comparing irinotecan and oxaliplatin in combination with the same infusional 5-FU/LV regimens and crossover in case of disease progression showed equivalent efficacy for both schedules in the first-line setting, but the irinotecan combination proved beneficial in terms of safety. New molecular targeted agents, such as angiogenesis-modulating compounds (e.g., bevacizumab) and epidermal growth factor receptor inhibitors (e.g., cetuximab), are under clinical investigation. This review updates current systemic frontline treatments and future perspectives for patients with advanced colorectal carcinoma.     

Oral capecitabine vs intravenous 5-fluorouracil and leucovorin: integrated efficacy data and novel analyses from two large, randomised, phase III trials

This study evaluates the efficacy of capecitabine using data from a large, well-characterised population of patients with metastatic colorectal cancer (mCRC) treated in two identically designed phase III studies. A total of 1207 patients with previously untreated mCRC were randomised to either oral capecitabine (1250 mg m(-2) twice daily, days 1-14 every 21 days; n=603) or intravenous (i.v.) bolus 5-fluorouracil/leucovorin (5-FU/LV; Mayo Clinic regimen; n=604). Capecitabine demonstrated a statistically significant superior response rate compared with 5-FU/LV (26 vs 17%; P<0.0002). Subgroup analysis demonstrated that capecitabine consistently resulted in superior response rates (P<0.05), even in patient subgroups with poor prognostic indicators. The median time to response and duration of response were similar and time to progression (TTP) was equivalent in the two arms (hazard ratio (HR) 0.997, 95% confidence interval (CI) 0.885-1.123, P=0.95; median 4.6 vs 4.7 months with capecitabine and 5-FU/LV, respectively). Multivariate Cox regression analysis identified younger age, liver metastases, multiple metastases and poor Karnofsky Performance Status as independent prognostic indicators for poor TTP. Overall survival was equivalent in the two arms (HR 0.95, 95% CI 0.84-1.06, P=0.48; median 12.9 vs 12.8 months, respectively). Capecitabine results in superior response rate, equivalent TTP and overall survival, an improved safety profile and improved convenience compared with i.v. 5-FU/LV as first-line treatment for MCRC. For patients in whom fluoropyrimidine monotherapy is indicated, capecitabine should be strongly considered. Following encouraging results from phase I and II trials, randomised trials are evaluating capecitabine in combination with irinotecan, oxaliplatin and radiotherapy. Capecitabine is a suitable replacement for i.v. 5-FU as the backbone of colorectal cancer therapy.     

伊立替康和奥沙利铂联合氟尿嘧啶类药物一线治疗晚期结直肠癌的临床观察

目的 观察伊立替康(IRI)和奥沙利铂(OXA)联合氟尿嘧啶类药物(5-FU/替吉奥胶囊/卡培他滨)一线治疗晚期结直肠癌的疗效和不良反应.方法 选取有可测量指标的晚期结直肠癌患者35例,第1天应用IRI 130~l60 mg/m2静脉滴注,同时予亚叶酸钙(CF)200 mg/m2静脉滴注后5-FU 400 mg/m2静脉推注,之后5-FU 2400 mg/m2持续泵注44 h;或替吉奥胶囊每次40~60 mg(根据体表面积确定),卡培他滨每次1000 mg/m2,早晚饭后各1次,连续服用10 d,停药4 d;第2天奥沙利铂85~100 mg/m2静脉滴注;14 d为1个周期.每3个周期评价疗效及相关毒性反应.结果 全组35例可评价疗效,中位化疗为4个周期(3~11).客观有效率(ORR)为54.3%(19/35),其中完全缓解(CR)1例,部分缓解(PR)18例.化疗后接受手术的25例患者中,20例患者达到R0切除(57.1%),其中18例患者系初始局部晚期,2例患者初始伴肝转移.所有35例患者在治疗期间,未出现治疗相关性死亡,3级不良反应发生率为54.3%(19/35),其中粒细胞下降发生率为20.0%(7/35),恶心发生率为17.1%(6/35),呕吐发生率为14.3%(5/35),腹泻发生率40.0%(14/35).4级不良反应主要为粒细胞下降发生率,发生率为17.1%(6/35).结论 三药联合方案一线治疗晚期结直肠癌近期疗效高,毒性反应可以耐受.     

Integrating oxaliplatin into the management of colorectal cancer

Oxaliplatin, a third-generation platinum analogue, is a novel compound with proven anti-tumor activity in colorectal cancer that has demonstrated synergy with 5-fluorouracil (5-FU) in human tumor xenograft models. A series of phase II trials demonstrated that, as second-line therapy, oxaliplatin in combination with 5-FU/leucovorin (LV) is active and can overcome clinical resistance to 5-FU. Subsequently, two large, randomized, phase III trials demonstrated that the addition of oxaliplatin to 5-FU/LV significantly improved response rates and time to disease progression in the first-line setting, but had no statistically significant impact on survival. Oxaliplatin in combination with 5-FU/LV represents an important treatment option for patients in whom 5-FU-based therapy has failed and as first-line therapy. Oxaliplatin has also been investigated in combination with the oral fluoropyrimidine, capecitabine. As an oral agent that exploits the high intratumoral activity of thymidine phosphorylase to generate 5-FU preferentially within tumor tissue, capecitabine may improve the efficacy and tolerability of fluoropyrimidine/oxaliplatin combination therapy. A phase I dose-escalation study has been performed in patients with advanced/metastatic solid tumors to establish the most appropriate regimen. The study indicated that the combination is feasible and has substantial antitumor activity in patients with colorectal cancer. This article provides an overview of the clinical trial data for oxaliplatin and discusses how oxaliplatin may best be used in the future.     

Cetuximab plus XELIRI or XELOX for first-line therapy of metastatic colorectal cancer

Modern chemotherapy combinations for metastatic colorectal cancer (mCRC) comprise infusional 5-fluorouracil (5-FU), leucovorin, and irinotecan or oxaliplatin. The fluoropyrimidine derivative capecitabine is at least as effective as 5-FU plus leucovorin bolus regimens. It displays a favorable toxicity profile and offers the advantages of oral administration. The epidermal growth factor receptor antibody cetuximab induces synergistic antitumor activity when combined with chemotherapy. In pretreated patients, cetuximab can restore the sensitivity to irinotecan and, therefore, has been registered in this setting. Several phase I/II trials have investigated the combination of cetuximab with irinotecan-based or oxaliplatin-based chemotherapy for the first-line treatment of mCRC. These combinations have been proven to be safe and have provided promising efficacy data. A recent phase III trial confirmed improved progression-free survival, response rates, and a particularly significant increase of secondary resection rates for the combination of FOLFIRI (infusional 5-FU/leucovorin/irinotecan) plus cetuximab compared with FOLFIRI alone. In this review, we discuss the background of combining XELIRI (capecitabine/irinotecan) or XELOX (capecit-abine/oxaliplatin) with cetuximab for the first-line treatment of mCRC and present available data of these combined cytotoxic and targeted treatment approaches.     

Review of capecitabine as oral treatment of gastric, gastroesophageal, and esophageal cancers

Capecitabine is a novel, orally administered fluoropyrimidine carbamate that has been approved for adjuvant treatment in patients with Stage III colon cancer, first-line metastatic colorectal cancer, and metastatic breast cancer, both as a single agent (for patients who are resistant to paclitaxel and anthracyclines) and in combination with docetaxel (after failure on anthracycline-based therapy). Capecitabine is being investigated in Phase I and II trials for the treatment of gastric, gastroesophageal, and esophageal cancers, primarily in the first-line metastatic setting but also in the adjuvant setting. The MEDLINE data base was searched for English-language clinical trials that were published from 1996 through October 2005 along with relevant abstracts that were presented at the American Society of Clinical Oncology and at meetings of the European Cancer Conference and the European Society of Medical Oncology. The most frequently investigated combinations were capecitabine with docetaxel, paclitaxel, cisplatin, or oxaliplatin, and capecitabine also has been combined with irinotecan. These therapies have yielded efficacy data that compare favorably with data from Phase III trials of parenteral 5-fluorouracil (5-FU) in the first-line metastatic setting, and they mostly are well tolerated. Capecitabine, when combined in doses <1250 mg/m(2) twice daily, consistently resulted in a lower frequency of Grade 3 or 4 toxic effects. Capecitabine, as a representative of oral fluoropymidine, is a promising agent in gastroesophageal cancers. Although some Phase III trials are completed, additional Phase III trials of capecitabine-based combinations that compare its efficacy and safety with parenteral 5-FU-based combinations, in both first-line metastatic and adjuvant settings, would be important.     

The role of new agents in the treatment of colorectal cancer

New drugs improved efficacy or convenience of treatment in metastatic colorectal cancer. The oral fluoropyrimidines capecitabine and UFT are less toxic but equally efficacious relative to intravenous bolus 5-fluorouracil (5-FU)/folinic acid (FA). These agents might be beneficial for patients who unlikely benefit from the more intensive combination therapy with infusional 5-FU/FA and irinotecan or oxaliplatin. First-line therapy with irinotecan or oxaliplatin and 5-FU/FA induces an objective response in up to 50% of the patients and may allow neoadjuvant concepts in unresectable liver metastasis. The combination therapy increased progression-free survival and in the case of irinotecan/5-FU/FA also overall survival when compared to 5-FU/FA. Sequential treatment with infusional 5-FU/FA plus oxaliplatin followed by 5-FU/FA plus irinotecan or vice versa results in a median survival exceeding 20 months. Thus, patients in a good performance status and with favorable prognostic parameters should be offered first-line combination treatment of irinotecan or oxaliplatin with 5-FU/FA, whereby 5-FU is preferably administered as an infusion for combination therapy. New targets in the treatment of colorectal cancer are the EGF and VEGF receptor. The monoclonal EGF receptor antibody cetuximab alone and in combination with irinotecan is active in second-line treatment. The VEGF antibody bevacizumab prolongs survival when given in combination with 5-FU/FA and irinotecan.