Role of chemotherapy in the treatment of colorectal carcinoma

Medical Management of Colorectal Carcinomas

Current information on the medical treatment of colorectal cancer was reviewed after a search of the literature through Medline. Publications from 1984 to present were surveyed. Appropriate adjuvant therapy increases overall survival and disease-free intervals. The treatment modalities of unresectable or metastatic tumors are disappointing, with at best 40% of patients experiencing short-lasting responses. Whenever possible, patients with advanced colorectal cancer should be enrolled in clinical trials.

Adjuvant Chemotherapy for Cancer of Gastrointestinal Tract: A Critical Review

Surgery is the only curative therapeutic approach for gastrointestinal tumors. If the tumor is deeply Infiltrating through serosa or invading regional lymph nodes, the 5-year patient's survival is about 60 % and < 40 %, respectively. The natural history and prognosis of neoplasms from colon, rectum and stomach are different. Despite the unsatisfactory results obtained with radical treatment of advanced disease, there are positive studies on adjuvant treatment of colon and rectal cancer, whereas the role of such an approach is still controversial for gastric cancer. The combination of fluorouracil containing chemotherapy with radiotherapy was suggested as the most effective adjuvant treatment for patients with Dukes’ B and C rectal cancer. However, the choice of chemotherapeutic regimen is still debated. A recent report, from the North Central Cancer Tumor Group, stated survival and disease-free survival advantages for patients with Dukes’ C colon cancer treated with FU + levamisole for 1 year after radical surgery. Since this regimen was not proven effective in advanced disease, ongoing adjuvant trials are comparing it with the combination of FU + biochemical modulator. The role of adjuvant therapy for gastric cancer is debated. The recent development of regimens active on advanced disease result in more promising future adjuvant trials.

High and low dose folinic acid, 5-fluorouracil bolus and continuous infusion for poor-prognosis patients with advanced colorectal carcinoma

OBJECTIVE

Evaluation and assessment of response rate, duration and toxicity in patients subjected to 5-FU based chemotherapy.

BACKGROUND

The therapeutic ratio shifts with different 5FU/LV regimens and none yet serve as the internationally accepted Gold Standard. A bimonthly regimen of high dose leucovorin is reported to be less toxic and more effective than monthly low dose regimens. We here compare therapeutic responses and survival benefit of the two regimens in poor prognosis patients with advanced colorectal carcinoma.

PATIENTS AND METHODS

A total of 35 patients with histologically confirmed colorectal carcinoma were subjected to de Gramont and Mayo Clinic regimen. Nineteen patients were treated with high dose folinic acid (200 mg/m2), glucose 5%, 5-FU (400 mg/m2) and 22 hr. CIV (600 mg/m2) for two consecutive days every two weeks. These patients had failed responses to previous chemotherapy and were above sixty years of age with poor general status. Sixteen patients (six below 60 years) with progressive disease were subjected to low dose folinic acid (20 mg/m2)for five days, 5FU(425 mg/m2) injection bolus for 5 days, every five weeks. An initial evaluation was made in sixty days and responders were reevaluated at sixty days interval or earlier in case of clinical impairment. Based on positive prognosis, the therapy was continued. Evaluation of treatment response was made on the basis of WHO criteria.

RESULTS

The response rate was 44% in thirty four evaluable patients, with 4 complete responses (11.8%) and 11 (32.4%) partial responses. The two schedules were well tolerated, whereas, mild toxicity without WHO Grade ≥ 2 events was assessed. The response duration was extended (12 months) in a few patients with age above sixty years treated by high dose bimonthly regimen of 5FU/LV.

CONCLUSION

The regimens are safe and effective in advanced colorectal carcinoma patients with poor general status.

Pharmacokinetic properties and antitumor efficacy of the 5-fluorouracil loaded PEG-hydrogel

Background

We have studied the in vitro and in vivo utility of polyethylene glycol (PEG)-hydrogels for the development of an anticancer drug 5-fluorouracil (5-FU) delivery system.

Methods

A 5-FU-loaded PEG-hydrogel was implanted subcutaneously to evaluate the drug retention time and the anticancer effect. For the pharmacokinetic study, two groups of male rats were administered either an aqueous solution of 5-FU (control group)/or a 5-FU-loaded PEG-hydrogel (treated group) at a dose of 100 mg/kg. For the pharmacodynamic study, a human non-small-cell lung adenocarcinoma (NSCLC) cell line, A549 was inoculated to male nude mice with a cell density of 3 × 10⁶. Once tumors start growing, the mice were injected with 5-FU/or 5-FU-loaded PEG-hydrogel once a week for 4 weeks. The growth of the tumors was monitored by measuring the tumor volume and calculating the tumor inhibition rate (IR) over the duration of the study.

Results

In the pharmacokinetic study, the 5-FU-loaded PEG-hydrogel gave a mean residence time (MRT) of 8.0 h and the elimination half-life of 0.9 h; these values were 14- and 6-fold, respectively, longer than those for the free solution of 5-FU (p < 0.05). In the pharmacodynamic study, A549 tumor growth was significantly inhibited in the 5-FU-loaded PEG-hydrogel group in comparison to the untreated group beginning on Day 14 (p < 0.05-0.01). Moreover, the 5-FU-loaded PEG-hydrogel group had a significantly enhanced tumor IR (p < 0.05) compared to the free 5-FU drug treatment group.

Conclusion

We suggest that 5-FU-loaded PEG-hydrogels could provide a useful tool for the development of an anticancer drug delivery system.

The X-ray structure of Salmonella typhimurium uridine nucleoside phosphorylase complexed with 2,2'-anhydrouridine, phosphate and potassium ions at 1.86 A resolution

Uridine nucleoside phosphorylase is an important drug target for the development of anti-infective and antitumour agents. The X-ray crystal structure of Salmonella typhimurium uridine nucleoside phosphorylase (StUPh) complexed with its inhibitor 2,2'-anhydrouridine, phosphate and potassium ions has been solved and refined at 1.86 A resolution (R(cryst) = 17.6%, R(free) = 20.6%). The complex of human uridine phosphorylase I (HUPhI) with 2,2'-anhydrouridine was modelled using a computational approach. The model allowed the identification of atomic groups in 2,2'-anhydrouridine that might improve the interaction of future inhibitors with StUPh and HUPhI.

Crystallization and preliminary X-ray diffraction analysis of Salmonella typhimurium uridine phosphorylase complexed with 5-fluorouracil

Uridine phosphorylase (UPh; EC 2.4.2.3) catalyzes the phosphorolytic cleavage of the N-glycosidic bond of uridine to form ribose 1-phosphate and uracil. This enzyme also activates pyrimidine-containing drugs, including 5-fluorouracil (5-FU). In order to better understand the mechanism of the enzyme-drug interaction, the complex of Salmonella typhimurium UPh with 5-FU was cocrystallized using the hanging-drop vapour-diffusion method at 294 K. X-ray diffraction data were collected to 2.2 A resolution. Analysis of these data revealed that the crystal belonged to space group C2, with unit-cell parameters a = 158.26, b = 93.04, c = 149.87 A, alpha = gamma = 90, beta = 90.65 degrees . The solvent content was 45.85% assuming the presence of six hexameric molecules of the complex in the unit cell.

Biweekly bolus 5-fluorouracil and leucovorin plus oxaliplatin in pretreated patients with advanced colorectal cancer: a dose-finding study

The primary objective of this study was to determine the maximum tolerable dose (MTD) and dose-limiting toxicity (DLT) for bolus 5-fluorouracil (5-FU) administered on a biweekly schedule and in combination with fixed doses of leucovorin (LV) and oxaliplatin. The secondary objectives were to evaluate the toxicity profile and antitumor activity of this regimen for pre-treated patients with advanced colorectal cancer. A total of 26 patients with documented fluoropyrimidine-resistant, advanced colorectal cancer were enrolled into this phase I study. Fixed dose of oxaliplatin (85 mg/m2) was delivered as an i.v. infusion over 2 h, followed by LV (20 mg/m2) and 5-FU bolus every 2 weeks. The starting dose of 5-FU was 600 mg/m2, which was then incremented by 100 mg/m2 for each dose level. The DLT was determined for the first two treatment cycles, while toxicity and efficacy were evaluated throughout treatment. Six dose levels were tested. The MTD of 5-FU was deemed to be 1000 mg/m2 since dose-limiting fatigue was noted for three of the five-patient cohort during the first two cycles of chemotherapy at dose level 6. The most frequent treatment-related toxicities during the study were neutropenia, vomiting, diarrhea, fatigue and neuropathy. In an intent-to-treat analysis, the objective response rate was 30.8% (95% confidence interval 11.8-49.8%) for the 26 patients. The combination of bolus 5-FU/LV and oxaliplatin every 2 weeks is a feasible and effective treatment at the recommended dosages. A phase II study, to more-precisely define activity and toxicity, is ongoing.

Effect of selenomethionine on N-methylnitronitrosoguanidine-induced colonic aberrant crypt foci in rats

An association between low selenium intake and the incidence or prevalence of cancers is well known. Selenium in the form of selenomethionine supplemented in drinking water has been found to be highly effective in reducing tumour incidence and preneoplastic foci during the development of hepatocarcinogenesis in rats in our previous studies. Here, an attempt has been made to investigate whether the dose and form of selenium found to be effective during hepatocarcinogenesis is equally effective in N-methylnitronitrosoguanidine-induced colorectal carcinogenesis in terms of antioxidant defence enzyme systems, DNA chain breaks and incidences of aberrant crypt foci. Treatment with selenomethionine either on initiation or on selection/promotion, or during the entire experiment showed that selenomethionine was most effective in regulating the cellular antioxidant defence systems, DNA chain break control and reducing aberrant crypt foci in the colorectal tissues of rats. Our results also confirm that selenium is particularly effective in limiting the action of the carcinogen during the initiation phase of this colorectal carcinogenesis, just as we found with hepatocarcinogenesis in our previous studies.

A simplified regimen of weekly high dose 5-fluorouracil and leucovorin as a 24-hour infusion in patients with advanced colorectal carcinoma

BACKGROUND

Reports of in vitro experiments in colorectal carcinoma cells suggest that prolonged cellular exposure to 5-fluorouracil (5-FU) combined with relatively low concentrations of leucovorin (LV) provides optimal enhancement of 5-FU efficacy. In this study, a simplified regimen of weekly 24-hour infusion of high dose 5-FU combined with a relatively low dose of LV was used to treat patients with advanced colorectal carcinoma.

METHODS

Thirty-six patients with advanced colorectal carcinoma received 5-FU, 2600 mg/m2, admixed with LV, 100 mg/m2, in a portable infusion pump administered intravenously over a 24-hour period. High dose 5-FU/LV was delivered once a week for 5 consecutive weeks followed by a 1-week recovery period. All patients were assessable for toxicity and response.

RESULTS

Two complete responses and 15 partial responses were observed (response rate of 47.2%; 95% confidence interval, 30.1-64.4%). The median response duration was 9.6 months. The median survival and time to progression were 11.9 months and 7.1 months, respectively. The toxicity was mild and acceptable. The major dose-limiting factors were hand-foot syndrome and fatigue.

CONCLUSIONS

This simplified regimen of weekly 24-hour continuous infusion of high dose 5-FU/LV is an effective regimen in the treatment of patients with advanced colorectal carcinoma. Further study of the pharmacokinetics of combination therapy with 5-FU and LV as used in this regimen and its correlation with response and toxicity is warranted.

Detection of carcinoembryonic antigen mRNA in the mesenteric vein of patients with resectable colorectal cancer

The detection of tumor cells in the drainage venous blood of patients with colorectal cancer was made feasible by demonstrating carcinoembryonic antigen (CEA) mRNA in the mononuclear cell component of the blood, using a nested reverse transcription-polymerase chain reaction. CEA mRNA was detected in the drainage venous blood from 11 (42%) of 26 patients, and the rate of detection increased according to the grade of vessel invasion. CEA mRNA was detected in all patients with synchronous liver metastases, even though there was no significant correlation between the presence of CEA mRNA in the drainage venous blood and the clinicopathological findings. As the presence of CEA mRNA in the drainage venous blood is an indicator of the spread of tumor cells in patients with colorectal cancer, this assay can be used to assess the possible outcome of patients with colorectal cancer, providing one more tool for the physician-oncologist to use in designing appropriate treatments.

Randomized trial comparing monthly low-dose leucovorin and fluorouracil bolus with weekly high-dose 48-hour continuous-infusion fluorouracil for advanced colorectal cancer: a Spanish Cooperative Group for Gastrointestinal Tumor Therapy (TTD) study

PURPOSE

The objective of this multicenter study was to compare the efficacy and toxicity profiles of a combination of 5-fluorouracil (5-FU) given by bolus injection together with intravenous leucovorin (LV) versus high-dose 5-FU in continuous infusion (CI) in the treatment of advanced colorectal cancer.

PATIENTS AND METHODS

A total of 306 patients were randomized to receive either 5-FU 425 mg/m2 given by bolus injection on days 1-5 plus intravenous (i.v.) LV 20 mg/m2 every four to five weeks or 5-FU 3.5 g/m2/week in a 48-hour CI. Therapy was continued until disease progression. Second-line chemotherapy was allowed in both arms.

RESULTS

The response rates in 306 patients with measurable lesions were 19.2% (modulated arm) and 30.3% (CI arm, P < 0.05). The median progression-free survival times were 23.5 weeks (modulated arm) and 25 weeks (CI arm, P = NS). Median survival times were 42.5 weeks (modulated arm) and 48 weeks (CI arm, P = NS). There were no significant differences in grade 3-4 toxicity profiles but if we consider all grades we observed more mucositis in the modulated arm and more hand-foot syndrome in the CI arm.

CONCLUSIONS

In terms of response rate, the continuous infusion regimen was more effective than the modulated regimen. There was no significant difference in survival and time to progression, and none in grade 3-4 toxicity.

Biomodulation of Fluorouracil in colorectal cancer

5-Fluorouracil (5-FU) remains the agent of choice for the treatment of colorectal cancer. Research has focused on the biomodulation of 5-FU in order to attempt to improve the cytotoxity and therapeutic effectiveness of this drug in the treatment of advanced colorectal cancer. Modulation of 5-FU by methotrexate (MTX), trimetrexate (TMTX), interferon-alpha (IFN-alpha), leucovorin (LV), or N-(phosphonacetyl)-L-asparte acid (PALA) has produced higher response rates than those observed with 5-FU alone. Methotrexate may improve the durability of response to or survival with 5-FU, but with inferior results compared with those in trials of 5-FU and leucovorin. Trimetrexate produces a number of responses, and further phase III trials are in progress to confirm the results of promising phase II trials with this drug. IFN-alpha has shown therapeutic efficiency when combined with 5-FU alone or with 5-FU and leucovorin, but latest studies with these combinations have shown increased toxicity. Initial single-institution phase I trials with 5-FU and PALA reported promising responses, but the latter responses with PALA were not substantiated in randomized multicenter trials. Leucovorin enhances the cytotoxic activity of 5-FU in vitro and in vivo, and several clinical trials have shown improved response rates and possible trends in improved survival when such therapy is compared with the use of 5-FU as a single-agent. More recent randomized trials have focused their attention on determining the optimal dose and schedule with this combination for producing a better clinical response with minimal toxicity. Schedules using infusional 5-FU appear to be the most active regimens when 5-FU is used as a single agent, as demonstrated by recent randomized trials. The Southwest Oncology Group (SWOG) and the Eastern Cooperative Oncology Group (ECOG) have performed separate randomized trials and have shown that the optimal regimens employ infusional 5-FU as a single agent, and that these are the least toxic regimens, perhaps more effective, and associated with a better quality of life. Future studies will focus on infusional regimens involving either short-term, high-dose protracted or long-term, low-dose protracted infusion of 5-FU, since these regimens have shown the most favorable toxicity spectrum and produced the longest survival times. Future research will also focus on the evaluation of various methods of delivery of 5-FU, including oral administration of the drug in combination with compounds that can modify its catabolism.

Postsurgical sequential methotrexate, fluorouracil, and leucovorin for advanced colorectal carcinoma: a preliminary study

BACKGROUND AND OBJECTIVES

The present study compared the effects of sequential methotrexate and fluorouracil followed by leucovorin rescue (MFL), as an adjuvant chemotherapy versus a combination of tegafur (UFT) and mitomycin C (MMC), on patient survival and recurrence after surgery for colorectal carcinoma.

METHODS

Between January 1990 and December 1995, a total of 46 patients with advanced colorectal cancer were treated postsurgically by adjuvant chemotherapy using MFL or UFT-MMC. Surgical treatment was performed according to standardized procedures for radical resection of colorectal cancer. The patients were stratified into two groups after surgery. The MFL regimen consisted of MTX (100 mg/m2) and 5-FU (600 mg/m2) at hour 24, followed by leucovorin rescue. The UFT-MMC regimen consisted of MMC (12 mg/m2) intraoperatively and MMC (6 mg/m2) ever other week after surgery for 2 months and oral UFT (375 mg/m2/day), a combination of tegafur and uracil in a molar ratio of 1:4, was continued for 3 years or longer depending on the patients tolerance.

RESULTS

The overall survival rates after surgery was significantly (P < 0.05) higher in the MFL than the UFT-MMC group. Recurrence rates were significantly lower in the MFL than the UFT-MMC Group, especially for liver recurrence. Disease-free survival was significantly (P < 0.05) higher in the MFL than the UFT-MMC group.

CONCLUSIONS

The present results demonstrated the superiority of MFL therapy for improving postsurgical survival in patients with advanced colorectal cancer, in particular for those patients with a high risk of recurrence following potential curative resection.

Antitumoral activity of liposomes and immunoliposomes containing 5-fluorouridine prodrugs

Liposomes and immunoliposomes containing cytotoxic agents may be highly efficacious in intracavity therapy of malignancies confined principally to the peritoneal cavity. To assess the feasibility of this locoregional treatment, we prepared two derivatives of 5-fluorouridine (5-FUR), a highly cytotoxic metabolite of 5-fluorouracile, and incorporated them into REV liposomes, prepared with the reverse phase evaporation method. Encapsulation efficiency, drug leakage, and stability were determined, and size analysis and differential scanning calorimetry were carried out to evaluate the drug delivery potential of liposomes containing 5'-palmitoyl-5-FUR, 5'-succinyl-5-FUR, or the parent drug 5-FUR. The most suitable drug for encapsulation, in terms of minimum leakage and encapsulation efficiency, was 5'-palmitoyl-5-FUR, which differential scanning calorimetry indicated as being firmly anchored to the lipid bilayer. Thus, 5'-palmitoyl-5-FUR was chosen to prepare a chemotherapeutic liposome-monoclonal antibody conjugate (immunoliposome). The covalent linkage between antibody and liposome was realized by coupling the thiolated monoclonal antibody AR-3 with REV liposomes, containing N-[4-(p-maleimidophenyl)butyryl]phosphatidylethanolamine. The cytotoxic activity of drug-bearing liposomes and immunoliposomes was evaluated on the HT-29 human colon adenocarcinoma cell line; the immunoliposomes had higher cytotoxicity than liposomes or 5-FUR. To explore the potential of these drug formulations in anticancer therapy, we ip injected liposomes or immunoliposomes into athymic mice ip grafted with human HT-29 cell line. In this mouse model, the immunoliposome containing 5'-palmitoyl-5-FUR displayed the best antitumoral activity, since on day 27 postgraft only 5% of residual tumor mass was present, compared to control mice; there was a close relationship between exposure time of tumor tissue to the drug and antitumor potency.

Antitumor effects of 5'-deoxy-5-fluorouridine in combination with recombinant human interleukin 2 on murine colon carcinoma 26

The antitumor activity of recombinant human interleukin 2 (rIL-2) in combination with 5'-deoxy-5-fluorouridine (doxifluridine; 5'-DFUR) against marine colon carcinoma 26 (Colon 26) was studied. BALB/c mice were treated daily for 15 days with 5'-DFUR, rIL-2 or both, beginning on day 7 after subcutaneous transplantation of Colon 26. While mice treated with 5'-DFUR or rIL-2 alone died of tumor growth with pulmonary metastases within 9 weeks posttransplantation, the survival time was significantly prolonged in mice treated with both 5'-DFUR and rIL-2. Most of the combination-treated animals showed the regression of local tumors and the inhibition of pulmonary metastasis. Histopathologically, many tumor cells were degenerated and necrotized, with marked infiltration of mononuclear cells including large granular lymphocytes (LGLs) with periodic acid-Schiff-positive cytoplasmic granules. The cells were positive for CD3 epsilon, asialo GM1 and NK1.1. Spleen cells from the combination-treated mice showed high activities of natural killer (NK) cytotoxicity as well as growth inhibition of Colon 26 and Meth A fibrosarcoma in mice. The results suggest that the combination therapy of 5'-DFUR plus rIL-2 enhanced non-specific cytotoxicity of LGL/NK cells for Colon 26 in tumor-bearing mice and was effective in the inhibition of tumor growth.

Outpatient weekly high-dose continuous-infusion 5-fluorouracil plus oral leucovorin in advanced colorectal cancer. A phase II trial. Spanish Cooperative Group for Gastrointestinal Tumor Therapy (TTD)

BACKGROUND

In a previous phase I-II trial we showed that the maximum tolerable dose (MTD) of 5-fluorouracil (5-FU) in a weekly 48-hour continuous infusion (CI) was 3.5 g/m2. In a subsequent confirmative phase II trial with 85 evaluable patients, a 38.5% response rate was obtained, and a median survival of 12 months. These data were comparable to those achieved by biochemical modulation of 5-FU with leucovorin. On this basis we attempted to modulate high-dose 5-FU (3 g/m2) with oral leucovorin (LV) but the regimen was too toxic and the dose had to be reduced. A new phase II trial with 2 g/m2/week plus oral leucovorin was planned.

PATIENTS AND METHODS

From July 1992 to June 1994, 110 previously untreated patients with advanced, measurable colorectal cancer were included in a multicenter study. The patients received, on an outpatient basis, 5-FU 2 g/m2 by continuous infusion for 48 hours once a week until progression or the appearance of toxic effects. Oral leucovorin (60 mg every six hours) was also given during the 5-FU infusion.

RESULTS

Patients received a median dose intensity of 5-FU of 1.6 g/m2/week (range 0.9-2). Three complete responses and 36 partial responses were observed. The overall response rate was 37.5% (95% CI, 28% to 46.8%), the median time to progression 7.4 months and median survival 14.5 months. W.H.O. grade 3 diarrhea occurred in 27 patients (24.5%); grade 3 mucositis was observed in 9 (8.1%) patients and grade 4 in one. Grade 3 nausea and vomiting was reported in 13 (11.7%) patients, while grade 3 hand-foot syndrome was detected in only 5 (4.5%). Grade 4 leukopenia occurred in one patient and grade 3-4 thrombocytopenia in two.

CONCLUSIONS

Oral leucovorin modulation of weekly 48-hour continuous infusion of 5-FU at 2 g/m2 is an active regimen, with diarrhea and mucositis as the main limiting toxic effects. Its antitumor activity does not seem superior to that obtained with a weekly 48-hour continuous infusion of 5-FU alone at a dose of 3.5 g/m2.

A phase II trial of weekly high dose continuous infusion 5-fluorouracil plus oral leucovorin in patients with advanced colorectal cancer. The Spanish Cooperative Group for Gastrointestinal Tumor Therapy (TTD)

BACKGROUND

In a previous Phase II trial, the authors showed that a weekly continuous infusion of 5-fluorouracil (5-FU) at a dose of 3.5 g/m2 for 48 hours is an active treatment for advanced colorectal cancer. The overall response rate was 38.5%, and the median survival was 12 months. These data were comparable to those achieved by biochemical modulation of 5-FU with leucovorin. To study the modulation of this weekly, high dose, continuous infusion 5-FU with oral leucovorin, a new Phase II trial was planned.

METHODS

From December 1991 to July 1992, 43 previously untreated patients with measurable advanced colorectal cancer were included in a multicenter study. They received on an outpatient basis 5-FU at a weekly dose of 3 g/m2 by continuous infusion for 48 hours until progression or toxicity. Oral leucovorin (60 mg every 6 hours) also was given during the infusion of 5-FU.

RESULTS

Patients received a median dose intensity of 5-FU of 2.2 g/m2/week (range, 0.76-3 g/m2/week). One complete response and 11 partial responses were observed. The overall response rate was 29% (95% confidence interval [CI], 16-45%). Median time to progression was 7 months, and the median survival was 15 months. World Health Organization Grades 3 and 4 diarrhea were observed in 19 (45%) and 6 (14%) patients, respectively. Grade 3 mucositis also was observed in 10 (24%) patients, and Grade 4 mucositis was observed in 1. Grade 3 nausea and vomiting were reported in seven (17%) patients. Grade 3 hand-foot syndrome was detected in only two (2.5%) patients. No leukopenia or thrombocytopenia was observed.

CONCLUSIONS

Oral leucovorin modulation of a weekly 48-hour infusion of 5-FU at a dose of 3 g/m2 of leucovorin is a toxic regimen, always requiring dose reduction, with diarrhea and mucositis as the main limiting toxicities. Its antitumor activity does not seem superior to that observed with a weekly 48-hour infusion of 5-FU alone at a dose of 3.5 g/m2.

Metabolism of 5-fluorocytosine to 5-fluorouracil in human colorectal tumor cells transduced with the cytosine deaminase gene: significant antitumor effects when only a small percentage of tumor cells express cytosine deaminase

The gene encoding cytosine deaminase (CD) has been expressed in the human colorectal carcinoma cell line WiDr. Metabolism studies confirm that tumor cells expressing CD convert the very nontoxic prodrug 5-fluorocytosine (5FCyt) to 5-fluorouracil (5FUra) and 5FUra metabolites. Tumor xenografts composed of CD-expressing cells can selectively generate tumor levels of > 400 microM 5FUra when the host mouse is dosed with nontoxic levels of 5FCyt. The selective metabolic conversion of 5FCyt to 5FUra in CD-expressing tumor cells results in the inhibition of thymidylate synthase and incorporation of 5FUra into RNA. 5FUra is also liberated into the surrounding environment when CD-expressing tumor cells are treated with 5FCyt. The liberated 5FUra is able to kill neighboring, non-CD-expressing tumor cells in vitro and in vivo. Most importantly, when only 2% of the tumor mass contains CD-expressing cells (98% non-CD-expressing cells), significant regressions in all tumors are observed when the host mouse is dosed with nontoxic levels of 5FCyt.

Docetaxel (Taxotere), a novel taxoid, in the treatment of advanced colorectal carcinoma: an EORTC Early Clinical Trials Group Study

Docetaxel (Taxotere), a new semisynthetic taxoid, is a potentially important chemotherapeutic agent for the treatment of cancer. Forty patients with bidimensionally measurable advanced adenocarcinoma of the colon were treated with docetaxel 100 mg m-2 every 3 weeks as a 1 h infusion without routine premedication. Thirty-nine patients were eligible: 23 males and 16 females. Median age was 60 years (range 41-75) and WHO performance status 1 (0-2). Prior adjuvant chemotherapy was performed in four patients and prior radiotherapy in nine patients. Bidimensionally measurable disease sites included: liver in 26 patients, lymph nodes and abdominal/peritoneal masses in 13, lung/mediastinal masses in ten and subcutaneous nodes in four. The median number of cycles given was 2 (range 1-15). Thirty-three patients were evaluable for response. One patient (3%) achieved a complete response and two (6%) (95% confidence limits 0-14%) a partial response. Side-effects were similar to those observed in other studies. Docetaxel, given at this dosage and schedule, has minimal activity in the treatment of colorectal carcinoma.

Anti-tumor effect of combined treatment with thymosin alpha 1 and interleukin-2 after 5-fluorouracil in liver metastases from colorectal cancer in rats

We studied the effect of combined chemo-immunotherapy, 5-FU followed by thymosin alpha 1 (T alpha 1) and interleukin-2 (IL-2) at low doses, on liver metastases from colorectal cancer, induced by splenic injection of DHD/K12 cells (1,2-dimethylhydrazine-induced colon adenocarcinoma) in syngeneic BDIX rats. The presence of liver metastases was checked by laparotomy 14 days after tumor-cell injection. Evaluable rats were assigned randomly to 5 experimental groups designated as control, 5-FU, IL-2, 5-FU/IL-2 and 5-FU/T alpha 1/IL-2. 5-FU was administered i.v. as a continuous infusion for 7 days by an osmotic device implanted surgically. T alpha 1 and IL-2 were administered for 4 days and repeated after 11 days. Combined chemo-immunotherapy was shown both to significantly reduce the growth of liver metastases and to prevent extra-hepatic spread. 5-FU/T alpha 1/IL-2 also improved survival rate. Combined immunotherapy after 5-FU restored NK activity of the peripheral-blood-mononuclear-cell (PBMC) in tumor and/or 5-FU immunodepressed rats and enhanced PBMC cytotoxic activity against the DHD/K12 autologous cell line. This model was devised to mimic the clinical situation of unresectable liver metastases.

Modulation of tumor cell response to chemotherapy by the organ environment

The outcome of cancer metastasis depends on the interaction of metastatic cells with various host factors. The implantation of human cancer cells into anatomically correct (orthotopic) sites in nude mice can be used to ascertain their metastatic potential. While it is clear that vascularity and local immunity can retard or facilitate tumor growth, we have found that the organ environment also influences tumor cell functions such as production of degradative enzymes. The organ microenvironment can also influence the response of metastases to chemotherapy. It is not uncommon to observe the regression of cancer metastases in one organ and their continued growth in other sites after systemic chemotherapy. We demonstrated this effect in a series of experiments using a murine fibrosarcoma, a murine colon carcinoma, and a human colon carcinoma. The tumor cells were implanted subcutaneously or into different visceral organs. Subcutaneous tumors were sensitive to doxorubicin (DXR), whereas lung or liver metastases were not. In contrast, sensitivity to 5-FU did not differ between these sites of growth. The differences in response to DXR between s.c. tumors (sensitive) and lung or liver tumors (resistant) were not due to variations in DXR potency or DXR distribution. The expression of the multidrug resistance-associated P-glycoprotein as determined by flow cytometric analysis of tumor cells harvested from lesions in different organs correlated inversely with their sensitivity to DXR: increased P-glycoprotein was associated with overexpression of mdr1 mRNA. However, the organ-specific mechanism for upregulating mdr1 and P-glycoprotein has yet to be elucidated.

Complete remission of liver metastases from colorectal cancer by treatment with a hepatic artery infusion (HAI) of interleukin-2-based immunochemotherapy: reports of three cases

In an attempt to improve the therapeutic efficacy against liver metastases, a hepatic arterial infusion (HAI) of interleukin-2 (IL-2)-based immunochemotherapy for anticipating the regional potentiation of hepatic lymphokine-activated killer (LAK)/tumor-infiltrating lymphocytes (TIL) was initiated. We present herein the cases of three patients with multiple liver metastases from colorectal cancer in whom complete remission was achieved by treatment with an HAI of IL-2 in combination with mitomycin C (MMC) and 5-fluorouracil (5-FU). These patients received an HAI of IL-2 at 8 x 10(5) JRU, 5-FU at 250 mg daily, and MMC at 4 mg once weekly for 3 weeks, being the induction regimen, after which they were discharged on maintenance therapy consisting of IL-2 at 2 x 10(6) JRU, 5-FU at 250 mg twice weekly, and MMC at 4 mg once weekly. It was evident from the liver CT scan taken after 2-3 months that the metastatic foci seen before therapy had clearly disappeared, while the serum carcinoembryonic antigen (CEA) had decreased to normal levels in all three patients. Pancytopenia was seen in one patient, but other laboratory studies of the hepatic and renal parameters were normal. The total lymphocyte count in the peripheral blood showed a mild decrease, while the lymphocyte phenotype study showed a notable increase in CD4+ cells and a decrease in CD8+ cells, with an elevation of a 4/8 ratio, in all cases during therapy. One patient relapsed with pelvic recurrence 14 months after the initiation of therapy, but the other two patients are still in remission 25 and 22 months after the initiation of therapy.

Mitomycin C, 5Fluorouracil and Folinic Acid in Combination with Alpha 2b Interferon for Advanced Colorectal Cancer

Aims and Background

This study was conducted to investigate the activity and toxicity of 5fluorouracll + folinic acid + mitomycin C combined with alpha 2b Interferon in advanced colorectal cancer based upon recent studies suggesting a possible biochemical modulation of 5 fluorouracil by interferon.

Patients and methods

Between June 1990 and April 1991 25 previously untreated patients with advanced colorectal carcinoma were treated with mitomycin C 10 mg/m2 iv bolus on day 1, 5fluorouracil 375 mg/m2 on days 1 to 4 and folinic acid 200 mg/m2 on days 1 to 4 every 4 weeks, combined with alpha 2b interferon 3 million U day continuously.

Response

Of the 25 patients entered into the study, 20 were evaluable for response as 5 patients withdrew due to toxicity (grade 3-4 thrombocytopenia in 4 cases and fatigue in 1). No complete response was recorded, 6 patients had partial remission (30 %; 95 % confidence interval, 10 % to 50 %), 4 experienced no change and 10 showed progressive disease. The toxicity of this regimen was significant, particularly myelosuppression.

Conclusions

This combination showed a significant toxicity and low response rate compared with other 5 fluorouracil based regimens in advanced colorectal cancer.

Level of serum gastrin as a predictor of liver metastasis from colorectal cancer

There have been no reports on the relationship between serum gastrin level and liver metastasis in human colorectal cancer. One hundred forty patients who underwent surgery for colorectal cancer (T2 or more) were enrolled in this study. Fasting serum gastrin level was determined prior to the surgery. Incidence of liver metastasis was significantly (P < 0.01) higher in patients with a serum gastrin level of > or = 150 pg/ml (37 percent; 14/38) than in those with a serum gastrin level of < 150 pg/ml (12 percent; 12/102). As for the tumors with venous invasion, liver metastasis was detected in 11 of 55 patients (20 percent) with a serum gastrin level of < 150 pg/ml; however, it was detected in 11 of 19 patients (58 percent) with a serum gastrin level of > or = 150 pg/ml (P < 0.01). These results suggest that serum gastrin serves as a useful predictor of liver metastasis from colorectal cancer and that the predictability of liver metastasis can be improved when both serum gastrin level and venous invasion are considered.

Reversal of 5-fluorouracil-induced toxicity by oral administration of uridine

BACKGROUND

Previous preclinical and clinical investigations have shown that the combined administration of 5-fluorouracil (5-FU) with delayed uridine can reverse side effects induced by 5-FU. This biochemical modulation-based combination may increase the therapeutic index of 5-FU.

PATIENTS AND METHODS

Seven patients with advanced cancer were treated weekly with 5-FU at increasing dosages starting at a dose of 600 mg/m2. Five patients developed dose-limiting leukopenia, and two patients developed thrombocytopenia. At the dose-limiting toxicity level, 5-FU treatment was repeated and followed after 3 hours by oral uridine (5 g/m2 q 6 hr) during 72 hours.

RESULTS

5-FU-induced leukopenia was reversed for several weeks after the administration of oral uridine. However, thrombocytopenia was not reversed. Side effects of the combined treatment consisted of mild diarrhea in five of the seven patients.

CONCLUSIONS

These data indicate that oral uridine can reduce the severity of 5-FU-induced myelosuppression.

Uridine allows dose escalation of 5-fluorouracil when given with N-phosphonacetyl-L-aspartate, methotrexate, and leucovorin

BACKGROUND

In a previous trial in which methotrexate and N-phosphonacetyl-L-aspartate (PALA) were used to modulate 5-fluorouracil (5-FU), four of six patients could not tolerate treatment at the 600 mg/m2 5-FU dose level because of mucositis, diarrhea, and a decrease in performance status. The current study examines the ability of uridine rescue to prevent such toxic effects in the same regimen and, thereby, allow additional dose escalation of 5-FU.

METHODS

Twenty-nine patients with advanced malignant neoplasms received PALA and MTX, each at 250 mg/m2, followed 24 hours later by increasing bolus doses of 5-FU (600-750 mg/m2) with a leucovorin rescue (10 mg orally every 6 hours for eight doses) and uridine rescue (3 g/m2/hour, for a 72-hour infusion, 3 hours on, 3 hours off). Treatment was repeated weekly with either 2 weeks on, 2 weeks off, or 3 weeks on, 1 week off.

RESULTS

Mucositis, which occurred in 4 of 12 patients treated at the 750 mg/m2 5-FU dose level, was the only significant chemotherapy-induced toxic effect. However, uridine-related central venous catheter complications (cellulitis in six patients and superior vena cava syndrome in one patient) precluded additional treatment on this protocol.

CONCLUSIONS

In the current regimen, uridine allowed dose escalation of 5-FU to 750 mg/m2, which some patients tolerated on a 3-week on, 1-week off schedule. Because of the vascular toxic effects associated with intravenous uridine, the authors recommend additional studies with oral uridine to determine whether the increase in 5-FU dose that uridine allows is associated with improved response rates.

Phase I Study of Fudr Continuous Infusion with Circadian Variability in Advanced Cancer Patients

A phase I study of floxuridine circadian infusion was performed in 14 patients with advanced solid tumors (9 colonic, 1 gastric, 4 renal). The starting dose was 0.15 mg/kg/day for 14 days followed by a 14-day therapy-free interval. Sixty-eight percent of the daily dose was infused between 3pm and 9pm. The dose was increased by 0.025 mg/kg/day for each successive course. Eighty-one cycles of therapy were given for a total of 1134 days of treatment. The mean dose intensity was 0.868 mg/kg/day for the entire group. The highest dose achieved (maximum tolerated dose) was 0.325 mg/kg/day. The most frequent toxicity was diarrhea (4.9 % of all courses) and nausea-vomiting (3.7 % of all courses). These side effects were of a low grade and all were resolved without hospitalization. Our results suggest the circadian modulation of floxuridine infusion.

Orthotopic and ectopic organ environments differentially influence the sensitivity of murine colon carcinoma cells to doxorubicin and 5-fluorouracil

We determined the effects of organ environment on the response of murine CT-26 colon carcinoma cells to 2 structurally and pharmacologically distinct chemotherapeutic agents. CT-26 cells were injected i.v. (to produce lung lesions), s.c., into the cecal wall, and into the spleen (to produce spleen and liver lesions). Doxorubicin (DXR) at 10 mg/kg, 5-fluorouracil (5-FU) at 20 mg/kg, or saline (control) was injected intravenously on different schedules after tumor-cell implantation. The in vivo responses of the tumors growing in the cecum, spleen, liver, lung and subcutis were compared. Colon carcinomas growing in the subcutis were most sensitive to DXR. Tumors growing in the spleen and cecum were most sensitive to 5-FU and less so to DXR. Tumors in the liver were highly resistant to both drugs, whereas experimental lung metastases were sensitive to 5-FU but resistant to DXR. The differential responses of the tumors to the drugs were not due to drug distribution. The level of protein-kinase-C activity was elevated in the spleen, liver and cecum tumors as compared with s.c. tumors and correlated with the in vivo DXR resistance of the tumor cells. This correlation suggested that organ environment may modulate the chemosensitivity of tumor cells, at least in part, by perturbing signal transduction pathways. Collectively, the data indicate that the organ environment has profound effects on the response of tumor cells to chemotherapy. A molecular understanding of this phenomenon should facilitate the design of more effective systemic chemotherapy for cancer metastases.

Prognostic factors in colorectal cancer

The prognostic power of the extent of tumour invasion is indisputable; Dukes' classification has repeatedly been proven to be strongly correlated with patient survival. Modifications have led only to confusion, resulting in caution being required in the classification of patients with Dukes' A tumours. In the UK, the American tumour node metastasis and Australian clinicopathological systems are frequently considered too complex for routine clinical use. Meanwhile, Jass's classification may be complicated by observer variation between pathologists, and recent evidence suggests that it offers no advantage over that of Dukes. All the conventional staging systems also fail to take the skill of the surgeon into account when determining outcome. Attempts at quantifying tumour structure have not heralded the expected major advance. For instance, the expense and uncertain prognostic value of tumour DNA content assessed by flow cytometry are likely to restrict widespread use of this technique. It may soon be possible, however, to provide optimum treatment for patients based on individual tumour doubling times. Classification using knowledge of how a small number of cells in the tumour have the ability to invade locally, enter blood vessels and metastasize would also provide important prognostic information on which treatment could be based. Until then, the ease of use and high prognostic power of Dukes' classification ensure that, after 60 years, it is still the 'gold standard' against which all other prognostic classifications in colorectal cancer should be assessed.

General condition of asymptomatic patients with advanced colorectal cancer receiving palliative chemotherapy. A longitudinal study

A Nordic multicenter study in asymptomatic patients with advanced colorectal cancer compared initial chemotherapy with sequential methotrexate-5-FU with leucovorin rescue (MFL) for 6 months versus primary expectancy with chemotherapy only after the appearance of symptoms. The study (183 patients randomized between January 1985 and February 1990) showed that symptom-free survival, progression-free survival and survival respectively were about 6 months longer in the group of patients randomized to initial MFL. Whether these prolongations could be achieved without an impaired 'quality of life' was studied in an associated study. Between January 1985 and March 1987, 43 patients were randomized at one of the hospitals, 36 of which were interviewed with a questionnaire at randomization. Even if all these patients were considered, by the physician, to be 'free of symptoms from their disease', 16/36 (44%) had symptoms that could be referred to the disease. In spite of this, the patients were in a good general condition, and considerably better off than patients considered to have 'symptoms from the disease' who were interviewed with the same questionnaire when randomized in a parallel study of symptomatic patients. Patients randomized to initial chemotherapy and interviewed longitudinally maintained their good condition throughout treatment. Toxicity was mild, although the patients expressed more adverse effects than the physicians recorded. Since symptom-free survival, progression-free survival and survival were statistically significantly longer in the group of patients randomized to MFL also in this associated study, it is concluded that initial chemotherapy can prolong symptom-free survival and survival without reduced 'quality of life' during the treatment period.

Angiotensin alteration of drug uptake in an experimental model of hepatic metastases

To evaluate the use of angiotensin-II (A-II) as a means of improving results with intra-arterial infusions of hepatic tumors, 32 New Zealand white rabbits underwent perfusion of VX-2 hepatic implants. Tritium-labeled fluorodeoxyuridine [( 3H]FUDR) was administered via peripheral ear vein in 9 control rabbits (iv), via the hepatic artery in 12 rabbits (HA), and following a constant infusion of A-II in the remaining 11 rabbits (HA/A-II). Biopsies of tumor and normal hepatic parenchyma were taken and tissue levels of FUDR measured. Hepatic artery infusions, both with and without A-II, resulted in a significantly greater tumor uptake of FUDR than the iv infusions (P less than 0.001). More importantly, the tumor/liver ratio of FUDR uptake was significantly greater in the HA/A-II group (3.40) than that in the HA without A-II (0.98) group (P less than 0.001). This difference is due to the decreased FUDR uptake by normal hepatic parenchyma in rabbits undergoing A-II infusion; tumor drug uptake is similar for both groups. We conclude that the addition of angiotensin II to hepatic artery infusional chemotherapy significantly improves the tumor/liver ratio of drug uptake in this experimental model of hepatic metastases.

Prostaglandin E1 enhances tumoricidal activity of 5-fluoro-2'-deoxyuridine in rats

Addition of prostaglandin E1 (PGE1) to 5-fluoro-2'-deoxyuridine (FUDR) infused via the portal vein has been shown to diminish both the regional and the systemic toxicity of this chemotherapeutic agent. The effect of concomitant PGE1 infusion on tumor growth has not yet been determined. This study was designed to assess the effect of PGE1 in combination with FUDR on an established adenocarcinoma in the rat model. Fifty-gram Fischer rats underwent placement of a 3-mm3 fragment of colon carcinoma 4047 in the left thigh pad. After 6 weeks to allow for tumor growth, the animals were randomly assigned to receive a 7-day intravenous infusion of (1) saline, (2) PGE1 (0.1 microgram/kg/min), (3) FUDR (3 mg/kg/day), or (4) PGE1 + FUDR. At 10 days animals receiving PGE1 + FUDR had a significant decrease in tumor volume (mm3, log 10) (3.39 +/- 0.24 vs 3.85 +/- 0.12, P less than 0.05) compared with animals receiving FUDR alone. We conclude that PGE1 may be useful as an adjunctive cytotoxic agent.

Thymopentin and interleukin-2 in combination with 5-fluorouracil and leucovorin in metastatic colorectal adenocarcinoma: preliminary results

Thymic hormones have been shown to exhibit immunorestorative effects in vivo and in vitro, and to enhance the expression of high affinity interleukin-2 (IL-2) receptors on normal human lymphocytes stimulated with phytohemagglutinin. Based on these data, a clinical trial was initiated to determine the effects of the combination of 5-fluorouracil (5-FU) and folinic acid (FA) with thymopentin (TP-5) and interleukin-2 (IL-2) in patients with advanced colorectal carcinoma. Fifteen patients were treated with FA, 200 mg/m2/day by IV bolus, and 5-FU, 400 mg/m2/day as a 30-minute infusion, both given for 5 consecutive days every 28 days. TP-5, 50 mg/day, was administered subcutaneously on days 8-11, and IL-2, 9 million IU/m2 twice daily, was given subcutaneously on days 12-16. Of 8 patients evaluable for response, 4 achieved a response. Two patients had stable disease, and two progressed during treatment. There were no instances of life-threatening toxicity. Two patients developed grade III stomatitis and diarrhea followed by leukopenia and fever, requiring hospitalization. Other toxicities were moderate. These results are only preliminary, and a larger number of patients and longer follow-up are needed to draw meaningful conclusions about the merits of this new approach in cancer treatment.

Interferon alpha-2a and 5-fluorouracil for advanced colorectal carcinoma. Assessment of activity and toxicity

Preclinical data showed that the cytotoxic effects of 5-fluorouracil (5-FU) are augmented by interferon (IFN). In a small study, 13 of 17 patients with advanced colorectal cancer responded to a regimen of 5-FU with IFN. Using the same dose and schedule as in this pilot study, 38 previously untreated patients with metastatic colorectal carcinoma were treated with continuous intravenous (IV) infusion of 5-FU 750 mg/m2 daily for 5 days, followed by weekly bolus 5-FU at 750 mg/m2 and subcutaneous IFN at 9 million units three times per week. Of 35 evaluable patients, nine (26%) had a partial response (95% confidence limit, 11% to 41%), with a median response duration of 7.5 months (range, 4.4 to greater than 11.7 months). Seven patients (20%) had a minor response, and ten (28%) had stable disease. The most common toxicities observed were stomatitis (52%) and diarrhea (43%). Neurotoxicity was seen in 34% of patients and consisted of gait disturbance, dizziness, confusion, memory loss, and dementia. Because of toxicity, 84% of patients required a reduction of the IFN dose by at least 50%, and 63% required reduction of the 5-FU dose by at least 25%. Although the combination of 5-FU and IFN in patients with advanced colorectal carcinoma has some activity, the regimen was toxic, and the observed response rate (26%) was not substantially superior to alternative 5-FU programs.

Effects of FUdR on primary-cultured colon carcinomas metastatic to the liver

Hepatic arterial infusion of fluorodeoxyuridine (FUdR) has demonstrated efficacy in the treatment of metastatic colorectal carcinoma of the liver. In this study, the direct cytotoxic effect of FUdR was measured on ten metastatic and two primary-site colorectal carcinomas in a primary culture assay system. Overall, clinically achievable concentrations of FUdR (0.4 to 4 microM) induced partial cell kill in 75% of tumors, including a greater than 50% reduction in viable tumor cell number in only two tumors and less than 50% in the remaining seven. Total cell kill was not observed in any tumor. Three tumors were resistant to these FUdR concentrations. Tumor sensitivity correlated with the size of the tumor growth fraction. Increasing the exposure time to FUdR from 3 to 7 days approximately doubled the magnitude of the response. 5-Flurouracil and cisplatin, at clinically achievable concentrations, were more toxic to metastatic tumor cells than FUdR. Because of the limited chemosensitivity of metastatic colorectal tumor cells to FUdR in vitro, we postulate that other mechanisms besides direct cytotoxicity contribute to the clinical efficacy of FUdR in vivo.

Intrahepatic mitomycin C as a salvage treatment for patients with hepatic metastases from colorectal carcinoma

Sixty-four evaluable patients with hepatic metastases from colorectal carcinoma, who did not have evidence of extrahepatic disease, were treated with intrahepatic (IH) mitomycin C (M) after disease progression or intolerance to treatment with IH fluorodeoxyuridine (FUDR). Eleven patients (17%) had a partial response (PR) to IH M and ten (16%) patients had stable disease. Patients who responded to IH FUDR were more likely to respond to IH M when compared with those who progressed on IH FUDR (47% versus 13%, respectively; P = 0.013). Those who were switched to IH M because of hepatotoxicity on IH FUDR also were more likely to respond to IH M than those who were switched because of progression on IH FUDR (75% versus 27%, respectively; P = 0.022). Baseline laboratory values, the percent of tumorous liver involvement, prior history of systemic chemotherapy, and the interval from diagnosis to initiation of IH M did not help predict response. Toxicity was mild and well tolerated. The overall median survival time of the 64 evaluable patients was 9.0 months from the start of IH M therapy. We conclude that IH M has some salvage benefit in patients with hepatic metastases.

Preoperative irradiation with and without chemotherapy (MFL) in the treatment of primarily non-resectable adenocarcinoma of the rectum. Results from two consecutive studies

Twenty-one consecutive patients with primarily non-resectable adenocarcinoma of the rectum were treated with preoperative split-course radiotherapy (40 Gy) and simultaneous sequential methotrexate + 5-fluorouracil + leucovorin (MFL). An initial infusion of methotrexate (250 mg/m2) was followed in the 2nd hour by 5-FU--first a bolus injection (10 mg/kg) and then continuous infusion (35 mg/kg/24 h) for 72 h. Leucovorin rescue (15 mg every 6 h) was initiated 24 h after the initial injection. Radiotherapy (10 Gy) was given with two 2.0 Gy fractions on days 1 and 2, and one fraction on day 3. The toxicity of the treatment was mostly mild to moderate. Compared with a previous consecutive series comprising 38 patients who received preoperative irradiation (greater than or equal to 40 Gy) only, with a resectability rate of 34%, the 71% resectability rate with this treatment seems to be superior.

Quality of life during cytostatic therapy for advanced symptomatic colorectal carcinoma: a randomized comparison of two regimens

Physician- and patient-rated 'quality of life' was studied in patients receiving chemotherapy for advanced symptomatic colorectal cancer. The patients participated in a Nordic multicentre randomized study comparing single-drug 5-fluorouracil (5-FU) with a combination of sequential methotrexate-5-FU with leucovorin rescue (MFL). Forty-four patients (all patients included at one of the hospitals) entered this associated 'quality of life' study, 22 in each group. In the MFL group, five patients had a partial remission (PR) and seven prolonged stationary disease (SD), whereas in the 5-FU group, only one patient had a PR and two SD. Median survival was longer in the MFL group (9 months) than in the 5-FU group (4 months). According to the physicians' judgement, 12 (55%) of the patients randomized to MFL experienced improved 'quality of life' compared to five (23%) in the 5-FU group. Patients' ratings gave the same figure (55%) in the MFL group, whereas only two (9%) patients in the 5-FU group considered themselves improved. The correlations between physicians' and patients' ratings were good. Adverse effects of treatment were minor and influenced ratings negatively only in one patient (5-FU group). Items that reflected changes in everyday activities discriminated better than other items in the 'quality of life' assessment. Since 'quality of life' measures were better in the MFL group in this associated study, and since objective and subjective responses, changes in Karnofsky performance status (KPS) and in survival also were better in the MFL group, not only in this study but also in the Nordic trial (249 patients randomized), we conclude that MFL is superior to 5-FU as a palliative treatment.