Phase II study of fluorouracil and recombinant interferon alfa-2a in previously untreated advanced colorectal carcinoma

High Dose Alpha-2B Interferon+Folinic Acid in the Modulation of 5-Fluorouracil. A Phase II Study in Advanced Colorectal Cancer with Evidence of An Unfavorable Cost/Benefit Ratio

The combination of folinic acid (FA) and 5-fluorouracil (5FU) is the most active systemic chemotherapy against advanced colorectal cancer. Experimental and clinical studies have suggested that the activity of 5FU can be improved by the addition of alpha-interferon (IFN). To evaluate the possibility of a double modulation of 5FU, a pilot study was conducted in the period July 1989-December 1989 with the following regimen: FA (200 mg/m2 i.v. bolus × 5 days) + 5FU (400 mg/m2 i.v. in 15 min × 5 days) + alpha-2b IFN (10 × 104 IU subcutaneously on alternate days). FA and 5FU administrations were repeated every 28 days; IFN was administered every week. In the 16 treated patients, 4 partial responses, 4 no changes, and 8 with progression of disease were observed, with an objective response rate of 25% (95% CI, 7.8%–55.1%). Median duration of response was 9.5 months, as was overall survival. Toxicity (fever, fatigue, neurotoxicity, stomatitis and diarrhea) was considerable and led to a reduction in IFN doses in 10/16 patients. Due to the unfavorable cost/benefit ratio, the study was closed and a new trial, with different doses and schedule of IFN, was started within the GISCAD (Italian Group for the Study of Digestive Tract Cancer).

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.

Chemoradioimmunotherapy with 5-fluorouracil, cisplatin and interferon-alpha in pancreatic and periampullary cancer: results of a feasibility study

BACKGROUND

Recent studies give rise to the hypothesis, that adjuvant chemoradioimmunotherapy with 5-fluorouracil (5-FU), cisplatin and interferon-alpha (IFN-alpha) might be a possible new treatment of pancreatic cancer in resected patients. We report the up-to-now experience at our institution.

PATIENTS AND METHODS

Eleven patients with histological diagnosis of localized carcinoma of the pancreas (n=7) or periampullary (n=4) were prospectively analyzed. Four patients were deemed unresectable because of local invasion of adjacent organs (neoadjuvant setting) and seven patients underwent curative resection (adjuvant setting). Eight patients were classified as T3 carcinomas and three T4 carcinomas. Fifty-five per cent (6/11) of the patients presented with positive lymph node involvement. One histological Grade I, six Grade II and three Grade III were detected. External conformal irradiation to a total dose of 50.4 Gy with 1.8 Gy per day was delivered. All patients received a concomitant chemotherapy with continuous 5-FU 200 mg/m2 per day on 28 treatment days and intravenous bolus cisplatin 30 mg/m2 per week (Day 2, 9, 16, 23, 30). A recombinant r-IFN-alpha was administered on three days weekly during Week one to five of the radiotherapy course as subcutanous injections with 3*3 Mio. I.U. weekly.

RESULTS

The four-year overall survival rate for all patients was 55%. In the neoadjuvant group, three of four patients died due to progressive disease; in the adjuvant group, combined chemoradioimmunotherapy lead to controlled disease in five of seven patients. The overall toxicity was well-managed.

CONCLUSION

Our data strengthens the hypothesis of concomitant chemoradioimmunotherapy with 5-FU, IFN-alpha and cisplatin as a possible new treatment of pancreatic cancer in resected patients.

The treatment of advanced colorectal cancer with interferon-alpha: a review

Colorectal cancer (CRC) is one of the most common malignancies in the western world. The majority of patients who develop this tumour will ultimately die from metastatic disease. The fluorinated pyrimidine 5 fluorouracil (5-FU) is at present the most active drug available for first-line therapy of this disease. Randomised studies have consistently demonstrated a survival advantage from early treatment with 5-FU in advanced CRC, which can be achieved without deterioration in quality of life. Despite over 30 years of use, the optimal 5-FU schedule remains controversial with a wide range of response rates reported in the literature. Single agent activity is in the order of 10-11%. In an attempt to improve response rates, modulation of 5-FU with a variety of agents has been intensively investigated. This article examines the role of interferon-alpha in the treatment of advanced CRC.

Phase III trial of postoperative cisplatin, interferon alpha-2b, and 5-FU combined with external radiation treatment versus 5-FU alone for patients with resected pancreatic adenocarcinoma -- CapRI: study protocol [ISRCTN62866759]

After surgical intervention with curative intention in specialised centres the five-year survival of patients with carcinoma of the exocrine pancreas is only 15%. The ESPAC-1 trial showed an increased five-year survival of 21% achieved with adjuvant chemotherapy. Investigators from the Virginia Mason Clinic have reported a 5-year survival rate of 55% in a phase II trial evaluating adjuvant chemotherapy, immunotherapy and external-beam radiation.

Colon cancer

Colon cancer is one of the leading tumours in the world and is considered among the big killers, together with lung, prostate and breast cancer. In the recent years very important advances occurred in the field of treatment of this frequent disease: adjuvant chemotherapy was demonstrated to be effective, chiefly in stage III patients, and surgery was optimized in order to achieve the best results with a low morbidity. Several new target-oriented drugs are under evaluation and some of them (cetuximab and bevacizumab) have already exhibited a good activity/efficacy, mainly in combination with chemotherapy. The development of updated recommendations for the best management of these patients is crucial in order to obtain the best results, not only in clinical research but also in everyday practice. This report summarizes the most important achievements in this field and provides the readers useful suggestions for their professional practice.

Rectal cancer

Rectal cancer is an important tumour from an epidemiological point of view and represents the benchmark for an optimal use of integrated treatments (surgery, radiotherapy and chemotherapy) in the oncological practice. Performing radio-chemotherapy (best if preoperatively), medical and radiation oncologists are now able to increase survival, to decrease the occurrence of pelvic recurrence and to ameliorate the quality of life of patients. Updated recommendations for the management of these patients are here reported.

Potential of interferon-alpha in solid tumours: part 2

The second part of this review examines the use of recombinant interferon-alpha (rIFNalpha) in the following solid tumours: superficial bladder cancer, Kaposi's sarcoma, head and neck cancer, gastrointestinal cancers, lung cancer, mesothelioma and ovarian, breast and cervical malignancies. In superficial bladder cancer, intravesical rIFNalpha has a promising role as second-line therapy in patients resistant or intolerant to intravesical bacille Calmette-Guérin (BCG). In HIV-associated Kaposi's sarcoma, rIFNalpha is active as monotherapy and in combination with antiretroviral agents, especially in patients with CD4 counts >200/mm(3), no prior opportunistic infections and nonvisceral disease. rIFNalpha has shown encouraging results when used in combination with retinoids in the chemoprevention of head and neck squamous cell cancers. It is effective in the chemoprevention of hepatocellular cancer in hepatitis C-seropositive patients. In neuroendocrine tumours, including carcinoid tumour, low-dosage (</=3 MU) or intermediate-dosage (5 to 10 MU) rIFNalpha is indicated as second-line treatment, either with octreotide or alone in patients resistant to somatostatin analogues. Intracavitary IFNalpha may be useful in malignant pleural effusions from mesothelioma. Similarly, intraperitoneal IFNalpha may have a role in the treatment of minimal residual disease in ovarian cancer. In breast cancer, the only possible role for IFNalpha appears to be intralesional administration for resistant disease. IFNalpha may have a role as a radiosensitising agent for the treatment of cervical cancer; however, this requires confirmation in randomised trials. On the basis of current evidence, the routine use of rIFNalpha is not recommended in the therapy of head and neck squamous cell cancers, upper gastrointestinal tract, colorectal and lung cancers, or mesothelioma. Pegylated IFNalpha (peginterferon-alpha) is an exciting development that offers theoretical advantages of increased efficacy, reduced toxicity and improved compliance. Further data from randomised studies in solid tumours are needed where rIFNalpha has activity, such as neuroendocrine tumours, minimal residual disease in ovarian cancer, and cervical cancer. A better understanding of the biological mechanisms that determine response to rIFNalpha is needed. Studies of IFNalpha-stimulated gene expression, which are now feasible, should help to identify molecular predictors of response and allow us to target therapy more selectively to patients with solid tumours responsive to IFNalpha.

Schedule-selective biochemical modulation of 5-fluorouracil in advanced colorectal cancer--a phase II study

BACKGROUND

5-fluorouracil remains the standard therapy for patients with advanced/metastatic colorectal cancer. Pre-clinical studies have demonstrated the biological modulation of 5-fluorouracil by methotrexate and leucovorin. This phase II study was initiated to determine the activity and toxicity of sequential methotrexate--leucovorin and 5-fluorouracil chemotherapy in patients with advanced colorectal cancer.

METHODS

Ninety-seven patients with metastatic colorectal cancer were enrolled onto the study. Methotrexate--30 mg/m2 was administered every 6 hours for 6 doses followed by a 2 hour infusion of LV--500 mg/m2. Midway through the leucovorin infusion, patients received 5-fluorouracil--600 mg/m2. This constituted a cycle of therapy and was repeated every 2 weeks until progression.

RESULTS

The median age was 64 yrs (34-84) and the Eastern Cooperative Group Oncology performance score was 0 in 37%, 1 in 55% and 2 in 8% of patients. Partial and complete responses were seen in 31% of patients with a median duration of response of 6.4 months. The overall median survival was 13.0 months. The estimated 1-year survival was 53.7%. Grade III and IV toxic effects were modest and included mucositis, nausea and vomiting.

CONCLUSIONS

This phase II study supports previously reported data demonstrating the modest clinical benefit of 5-FU modulation utilizing methotrexate and leucovorin in patients with metastatic colorectal cancer. Ongoing studies evaluating 5-fluorouracil modulation with more novel agents (Irinotecan and/or oxaliplatin) are in progress and may prove encouraging.

Results of a randomised phase II study of cisplatin plus 5-fluorouracil versus cisplatin plus 5-fluorouracil with alpha-interferon in metastatic pancreatic cancer: an EORTC gastrointestinal tract cancer group trial

A randomised phase II study of 5-fluorouracil (5-FU) plus cisplatin (CDDP) with or without alpha-interferon 2b was performed in patients with pancreatic cancer with measurable metastatic disease outside the pancreas. The treatment in arm A consisted of cisplatin (100 mg/m(2)) on day 1, followed by a continuous infusion of 5-FU 1000 mg/m(2) for 4 days and in arm B the same treatment was given plus alpha-interferon 2b in a dose of 3 million Units/day subcutaneously (s.c.) from day 1 for 5 days. 36 patients were entered in the trial, 18 in each arm. In arm B only 15 patients were eligible. No responses were observed in the 5-FU/CDDP arm and only 2 partial responses were achieved in the interferon-arm, lasting 27 and 32 weeks, respectively. Both treatment arms showed considerable toxicity. It has to be concluded that both treatment regimens have little activity and cannot be recommended.

Systemic irinotecan or regional floxuridine chemotherapy prolongs survival after hepatic cryosurgery in patients with metastatic colon cancer refractory to 5-fluorouracil

Most colorectal cancers metastatic to the liver are resistant to chemotherapy and are not amenable to surgical resection. This study evaluated our 6-year experience (July 1992-July 1998) in treating patients with unresectable hepatic colorectal metastases refractory to systemic 5-fluorouracil (5-FU). One hundred fifty-three patients underwent cryosurgical ablation (CSA) of 5-FU-resistant hepatic metastases. The patients then received either hepatic arterial floxuridine (FUDR), systemic CPT-11, or no postoperative adjuvant chemotherapy. Number, size, and location of hepatic metastases, carcinoembryonic antigen (CEA) levels, and type of postoperative treatment were analyzed. One to 15 lesions were frozen (median number, 3; median size, 6 cm), for a total of 73 synchronous and 80 metachronous lesions. Overall median survival was 28.4 months from the date of diagnosis of liver metastases and 16.1 months from the time of CSA. After cryosurgery alone, median survival was 13 months, which was significantly shorter than the post-CSA survival of 23.6 months with adjuvant CPT-11 and 21.2 months with hepatic FUDR (P = 0.007). Predictors of survival included preoperative CEA, postoperative reduction in CEA, and adjuvant chemotherapy (P < 0.05). Neither size, number of lesions, nor tumor location impacted survival. At a median follow-up of 13 months, 67% of patients have recurred (35% hepatic, 16% extrahepatic, and 49% both). Twenty percent of the recurrences were in the lobe of the CSA site. The 25 patients who underwent a second CSA had a median survival of 28.4 months from CSA and 40 months from the date of diagnosis of liver metastases. These data indicate that CSA offers an effective alternative for unresectable patients resistant to 5-FU. Systemic CPT-11 or regional FUDR may further prolong survival after CSA.

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

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

Progress in colorectal cancer chemotherapy: how far have we come, how far to go?

Fluorouracil has been the mainstay of treatment for colorectal cancer (CRC) for almost 40 years. Various schedules and biochemical modulators have been investigated in an attempt to improve the therapeutic efficacy of fluorouracil. To date, fluorouracil plus folinic acid represents the standard therapy in CRC for the adjuvant treatment of patients at high risk for relapse and for the first-line treatment of metastatic disease. To gain clinical acceptance, however, oral fluoropyrimidines must confer at least the same survival advantages associated with the optimal intravenous fluorouracil regimens. Irinotecan and oxaliplatin are 2 other novel agents that have mechanisms of action that are uniquely different from those of fluorouracil, with demonstrated activity in patients with fluorouracil-refractory disease. Recent randomised trials comparing fluorouracil plus folinic acid with combinations of either irinotecan or oxaliplatin and fluorouracil plus folinic acid have shown that response rates are improved and time to progression is increased in patients receiving the combination regimens. These regimens are being rapidly introduced in the adjuvant setting, and the role and acceptance of these combination regimens as first-line therapy needs to be defined. Other novel agents being evaluated in the treatment of patients with advanced CRC include oral edrecolomab (monoclonal antibody 17-1A) and tumour vaccines. Future research is focused on enabling clinicians to individualise treatment strategies in patients with CRC, so as to improve clinical outcomes and reduce drug toxicity.

Immunomodulation therapy in colorectal carcinoma

There has been much progress in the understanding of the relationship between the immune system and colorectal cancer. This has led to the use of immunomodulatory therapy in the adjuvant and palliative treatment of the condition. Although attempts at the use of non-specific immunomodulation with agents such as levamisole, cimetidine, alpha interferon and Bacillus Calmette-Guerin (BCG) have not produced significant clinical benefits when tested in randomized trials in both the adjuvant setting and for metastatic disease, promising results are being obtained with more specific therapy. Edrecolomab [corrected], a murine monoclonal antibody targeting the 17-1A antigen on malignant colorectal cells has produced a reduction in relapse and mortality rates when used as adjuvant treatment following surgery for Dukes' C colon cancer. Active specific therapy with autologous tumour vaccine administered with BCG has produced similar benefits in Dukes' B cancer. Both 3H1 anti-idiotypic antibody against carcinoembryonic antigen and 105AD7 antibody to gp72 glycoprotein have demonstrated in-vitro and in-vivo immune activation against tumour. Non-randomized studies postulate prolongation of survival using these antibodies in advanced disease. These agents are all currently being tested in randomized studies powered to detect meaningful survival differences and clinical benefit. Immune therapy offers the potential of low toxicity therapy in colorectal cancer and may have a role as an adjunct to conventional chemotherapy.

Retrospective evaluation of 5-fluorouracil-interferon-a aTreatment of advanced colorectal cancer patients

The authors describe the retrospective analysis of treatment by 5-fluorouracil and interferon-a aof 34 patients with advanced colorectal cancer. An average of 4.6 treatment cycles (3 12) was applied. Complete remission was not observed; partial remission was observed in 8 patients; in 13 patients no change occurred and progression was detected in 14 cases. Remission rate was 22.8%, mean response time was 5.2 (3 12) months, mean progress-free survival 5.6 (0 22) months. Mean survival from the start of treatment was 11.9 (1 42) months and from the establishment of the diagnosis 26.1 (3 60) months. Severe life-threatening side-effects did not occur; other side-effects such as fever, nausea, diarrhea, leucopenia, and anemia responded to drugs. Treatment by 5-FU and interferon, in accordance with other authors findings, improved survival and well-being of patients but no breakthrough has been achieved.

Sequential biochemical modulation of fluorouracil with folinic acid, N-phosphonacetyl-L-aspartic acid, and interferon alfa-2a in advanced colorectal cancer

PURPOSE

Several agents have been evaluated for their effect as biochemical modulators of fluorouracil (5-FU) in the treatment of metastatic colorectal carcinoma. In this study, we used folinic acid (FA), N-phosphonacetyl-L-aspartic acid (PALA), and recombinant interferon alfa-2a (IFNalpha-2a) in a sequential order to assess the efficacy of this approach in patients with metastatic colorectal carcinoma.

PATIENTS AND METHODS

Forty-four patients with metastatic colorectal carcinoma were enrolled onto the study. The treatment course consisted of three cycles: (cycle 1) FA 20 mg/m(2) followed by 5-FU 425 mg/m(2) on days 1 to 5; (cycle 2) PALA 250 mg/m(2) on days 29, 36, 43, and 50 and 5-FU 2,600 mg/m(2) as a 24-hour infusion on days 30, 37, 44, and 51; and (cycle 3) IFNalpha-2a 9 million units (MU) three times a week for 5 weeks beginning on day 57, with a continuous infusion of 5-FU 750 mg/m(2) on days 57 to 61, and then weekly bolus of 5-FU 750 mg/m(2)/wk on days 71, 78, and 85. Response was determined after cycle 3.

RESULTS

All patients had a Zubrod performance status >/= 2, measurable disease, and had received no prior chemotherapy for their metastatic disease. A total of 212 cycles were given. Thirty-six patients were assessable for response. No complete responses were seen. Seven patients had a partial response, eight had stable disease, and 15 had progressive disease. The median duration of response was 25 weeks, and the median survival was 53 weeks. Grade 3 and 4 toxic effects included granulocytopenia, stomatitis, diarrhea, rash, nausea, and fatigue.

CONCLUSION

This trial provided no evidence that sequential biochemical modulation of 5-FU in patients with metastatic colorectal carcinoma had any therapeutic advantage over conventional treatment regimens of 5-FU plus FA.

A randomized phase II trial of 5-fluorouracil, with or without human interferon-beta, for advanced colorectal cancer

This study compared the efficacy and safety of 5-fluorouracil (5-FU) monotherapy to that of 5-FU combined with natural human interferon-beta (IFN-beta) in patients with unresectable, advanced colorectal carcinoma. Forty-nine chemotherapy-naive patients were randomized to 5-FU alone or to the combination. All patients received 750 mg m(-2) day(-1) 5-FU for 5 days by continuous intravenous (i.v.) infusion, followed after day 15 by a weekly i.v. bolus of 750 mg m(-2). IFN-beta was injected intramuscularly three times weekly at 9 M IU. Treatment continued for 52 weeks, or until disease progression or intolerable toxicity. Clinical endpoints were tumor response, time to progression, survival and toxicity. The addition of IFN-3 to 5-FU significantly improved response rate (33.3% vs 4.5% for evaluable patients; P = 0.021), time to progression (median 7.2 vs 4.2 months; P = 0.0435), and survival time (median 15.9 vs 7.2 months; P = 0.038) without significantly increasing toxicity compared to 5-FU alone. Cumulative 5-FU dose was higher with combined therapy (P < 0.001): more patients receiving monotherapy discontinued treatment because of disease progression. Fever was more frequent with combined therapy (P = 0.008); there were no other differences in toxicity. The only grade IV toxicity observed was neutropenia (two patients per group). A randomized phase III trial has been initiated to confirm the synergy between 5-FU and IFN-beta.

Biochemical modulation of 5-fluorouracil by leucovorin with or without interferon-alpha-2c in patients with advanced colorectal cancer: final results of a randomised phase III study

5-Fluorouracil (5-FU) remains the mainstay of treatment for advanced colorectal carcinoma, although response rates are generally less than 20%. Improved therapeutic efficacy has been reported using biochemical modulation of 5-FU by leucovorin (LV) or interferon alpha (IFN), the combination of 5-FU/LV frequently considered as standard therapy in metastatic colorectal cancer. In an attempt to enhance the cytotoxicity of 5-FU, a prospective randomised trial was initiated to compare 5-FU/LV with 5-FU/LV plus IFN. Patients were randomised to receive either LV, 100 mg/m2 intravenously (i.v.), followed by 5-FU, 500 mg/m2 as a 1-h i.v. infusion, daily for 4 days, followed by weekly infusions until week 8, or the same regimen of 5-FU/LV plus IFN-alpha-2c, 30 micrograms subcutaneously (s.c.), three times weekly. Cycles were repeated after a 2-week rest period. Among 269 enrolled patients, 219 were available for response and 243 for toxicity. An objective tumour response was observed in 38 of 107 (36%) and 28 of 112 (25%) patients in the treatment arms with and without IFN, respectively (difference not significant). There was no significant difference between the two groups in response duration (median 8.4 versus 12.1 months), time to treatment failure (median 6.5 versus 4.9 months), or overall survival (median 10.0 versus 12.6 months). However, patients in the IFN arm experienced significantly more haematological and gastrointestinal toxicity and more frequent alopecia. In conclusion, the addition of IFN to 5-FU/LV in the schedules and doses used in the study did not provide any clinical benefit over 5-FU/LV alone and cannot be recommended for routine use in the treatment of advanced colorectal cancer.

Biomodulation with sequential intravenous IFN-alpha2b and 5-fluorouracil as second-line treatment in patients with advanced colorectal cancer

A phase II trial was carried out by the Grupo Oncologico Cooperativo del Sur (G.O.C.S.) to assess the efficacy and toxicity of a biochemical modulation of 5-fluorouracil (5-FU) by i.v. pretreatment with interferon (IFN)-alpha2b in patients with advanced colorectal carcinoma refractory to previous therapy with 5-FU modulated by methotrexate (MTX) or leucovorin (LV) or both. Between January 1993 and October 1995, 34 patients were entered on the study. The treatment was IFN-alpha2b 5 x 10(6)/m2 IU in a 1-h i.v. infusion, followed immediately by 5-FU 600 mg/m2 i.v. bolus injection. Courses were repeated weekly until observation of progressive disease or severe toxicity. One patient could not be assessed for response. Objective regression was observed in 2 of 33 patients (6%, 95% confidence interval, 0%-14%). No patient achieved a complete response. Two patients had partial responses (6%). No change was recorded in 14 patients (41%), and progressive disease occurred in 17 (52%). The median time to treatment failure was 3 months, and the median survival was 5 months. Toxicity was within acceptable limits. The main side effects were mucositis and diarrhea. Four episodes of grade 2 stomatitis were observed, causing dosage modifications. The most frequent toxic effects attributable to IFN-alpha2b were mild fatigue and fever. In conclusion, second-line therapy with i.v. IFN-alpha2b preceding 5-FU has shown an interesting profile of activity in a patient population with clearly unfavorable characteristics. From this perspective, further appropriately designed studies are needed to identify the greatest potential of IFN-alpha2b as a modulator of 5-FU.

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.

Adjuvant therapy for colorectal cancer: present and future perspectives

In recent years, adjuvant therapy for colorectal cancer has advanced considerably. This article reviews these advances and provides an update of the most recent and ongoing trials. In 1990, adjuvant therapy became the "standard of care" for patients with Stage III colon cancer (Dukes C) in the United States. Recent clinical trial data indicate that adjuvant treatment may also be effective in patients with Stage II (Dukes B2) colon cancer. The combination of 5-fluorouracil plus leucovorin may slightly improve survival (5-10 percent) compared with the standard 5-fluorouracil plus levamisole combination. The three-drug regimen (5-fluorouracil plus levamisole plus leucovorin) is more toxic, with no superior effect on survival. Intraportal chemotherapy, although it may significantly improve patient survival, does not decrease the frequency of liver metastases. However, it is still a promising form of adjuvant therapy owing to its short treatment period and relatively equivalent effects in survival compared with that of systemic therapy. For patients with Stage II or Stage III rectal cancer, postoperative systemic 5-fluorouracil plus radiation therapy plus protracted venous 5-fluorouracil infusion is the most effective postoperative adjuvant regimen. However, results from several studies show that preoperative radiation alone or chemoradiation for advanced local rectal cancers might also be effective while also improving resectability, decreasing morbidity, and increasing the chance that a sphincter-sparing procedure may be performed. The role of leucovorin in rectal cancer remains to be determined. Immune therapies with agents such as interferon-alpha-2a, monoclonal antibody 17-1A, and autologous tumor vaccines are being assessed and could further improve survival.

Human recombinant interferon alpha-2a plus 3'-azido-3'-deoxythymidine. Synergistic growth inhibition with evidence of impaired DNA repair in human colon adenocarcinoma cells

We reported that 3'-azidothymidine-3'-deoxythymidine (AZT) plus 5-fluorouracil or methotrexate produces additive cytotoxicity in HCT-8 cells: a reflection of increased AZT metabolism when de novo thymidylate (dTMP) synthesis was inhibited. We now report that AZT plus human recombinant interferon alpha-2a (rIFN-alpha 2a) produces synergistic growth inhibition in these cells. Evaluation of the effect of rIFN-alpha 2a on dTMP metabolism revealed that exposure to rIFN-alpha 2a (+/-AZT) did not affect dTMP synthase activity significantly but increased thymidine (dThd) kinase activity significantly. Consequently, AZT nucleotide production and incorporation into DNA were increased by coexposure to rIFN-alpha 2a. This alone, however, cannot explain the observed synergism. Therefore, the effect of these agents on DNA excision/repair processes was assessed. Isotope clearance studies demonstrated that rIFN-alpha 2a did not alter the rate of [3H]AZT excision from DNA. In contrast, filter-elution studies revealed that rIFN-alpha 2a (+/-AZT) produced more DNA damage and delayed repair compared with the effects produced by AZT alone. Since DNA polymerases alpha and beta are directly involved in gap-filling repair synthesis, experiments next assessed the effect of rIFN-alpha 2a and/or 3'- azido-3'-deoxythymidine-5'-triphosphate (AZTTP) on their activities. Polymerase alpha was inhibited slightly by AZTTP but not by rIFN-alpha 2a. Polymerase beta activity, however, was inhibited dramatically by rIFN-alpha 2a + AZTTP. Finally, western analysis revealed that a 24-hr exposure to 5000 IU/mL rIFN-alpha 2a (+/-20 microM AZT) significantly reduced wild-type p53 expression compared with AZT-exposed cells. We conclude that rIFN-alpha 2a enhances AZT-induced tumor cell growth inhibition by (i) increasing AZT metabolism, and (ii) inhibiting DNA repair and p53-mediated cell cycle control processes.

A phase II study of recombinant interferon-beta (r-hIFN-beta 1a) in combination with 5-fluorouracil (5-FU) in the treatment of patients with advanced colorectal carcinoma

The combination of 5-fluorouracil (5-FU) and interferon-alpha (IFN-alpha) has reported activity in the treatment of advanced colorectal carcinoma. Laboratory studies of IFN-beta suggest that this agent may offer theoretical advantages over IFN-alpha in combination with 5-FU. A total of 27 patients with advanced or recurrent colorectal carcinoma were treated in a non-randomized open phase II study with a combination of 5-fluorouracil (750 mg m(-1) daily for 5 days as a continuous intravenous (i.v.) infusion followed, from day 15, by i.v. bolus 750 mg m(-2) every 7 days) and recombinant interferon-beta [r-hIFN-beta-1a; 9 MIU (total dose) by subcutaneous injection from day 1 on every Monday, Wednesday and Friday throughout the treatment period]. Toxicity was less than that seen with this schedule of 5-FU in combination with IFN-alpha. Among 21 evaluable patients, four objective responses were seen. Recombinant human interferon-beta-1a in combination with 5-FU is an acceptable regimen in terms of toxicity. However, the study did not demonstrate a superior response rate when compared with previous reports of treatment with 5-FU alone or in combination with IFN-alpha.

Interleukin 2 and interferon alpha-2a do not improve anti-tumour activity of 5-fluorouracil in advanced colorectal cancer

Treatment using a combination of 5-fluorouracil (5-FU), interferon-alpha (IFN alpha-2a) and interleukin 2 (IL-2) has been shown to mediate disease regression in selected patients with advanced colorectal cancer. This phase II study was designed to evaluate the anti-tumour activity and toxicity of the combination of IL-2, IFN alpha-2a and 5-FU in patients with advanced colorectal cancer. Forty-four patients with metastatic colorectal cancer were treated, predominantly on an outpatient basis, with subcutaneous IFN alpha-2a and IL-2 three times per week followed by once a week bolus intravenous 5-FU injections. There were six (14%) partial responses among the 43 evaluable patients [95% confidence interval (CI) 5-28%]. Twenty-four patients had stable disease (56%) and 13 patients (30%) showed progressive disease. The median time to progressive disease in 43 patients was 19 weeks (range 2-72 weeks) and in responders 34 weeks (range 24-30 weeks). The median overall survival was 47 weeks (range 2-85 weeks) and in responders 60 weeks (range 35-71 weeks). Treatment-related toxic effects included fatigue, nausea and vomiting. Granulocytopenia was the main reason for the dose reductions or treatment interruptions in 32 out of 44 patients. One patient died of toxicity due to renal failure. Serial assessments of immunophenotyping and cytolytic activities of peripheral blood lymphocytes did not show changes in the numbers of circulating natural killer (NK) cells or in the levels of NK and lymphokine-activated killer (LAK) cytolytic activities. This regimen of IL-2 and IFN alpha-2a with 5-FU has only modest anti-tumour activity in advanced colorectal cancer.

Factors influencing response rates for advanced colorectal cancer chemotherapy

BACKGROUND

The activity of various chemotherapy regimens used in the treatment of advanced colorectal cancer is assessed by different groups of investigators and in various trials by what appear to be common criteria. However, there may be substantial inter-trial variation in the interpretation and application of these criteria which contributes to differences in response rates reported for the same regimen.

MATERIALS AND METHODS

This paper reviews the most prominent studies in this field and examines the factors which may influence the assessment of activity in clinical trials such as patient selection, the definition and application of response criteria, the methods of assessment of time to progression and duration of response, factors related to the therapeutic regimen and statistical methods. Each factor is critically discussed.

RESULTS

The analysis confirms that there is a large variability among the different studies and that an inter-trial comparison is often impossible, with subsequent difficulties for clinicians in determining the true impact of therapies.

DISCUSSION

After briefly commenting on the various issues, this review makes recommendations about how to achieve consistency among trials, for instance by using standard criteria, by extending the use of randomization even in phase II trials and by evaluating high quality, well conducted clinical trials in a meta-analysis, thereby making possible comparison across trials. The conclusions, although specific to colorectal cancer, are also applicable to other advanced malignancies.

Chemotherapy for pancreatic carcinoma

BACKGROUND

Pancreatic cancer is an aggressive disease and its patients typically have a short survival, usually marked by pain and rapid debilitation. The disease has been considered relatively chemoresistant, although many chemotherapy regimens have been described.

METHODS

Clinical results with chemotherapy, since the first publication of response in 1960, were reviewed for efficacy and toxicity. Emphasis was given to prospective trials with adequate power and clear evaluation criteria and endpoints.

RESULTS

Published response rates vary enormously in this disease, with rates in earlier single-institution trials tending to be much higher than those in studies with stringent response criteria, particularly recent cooperative group trials. Using stringent criteria, the upper limit of the objective response rate is approximately 20%. No convincing improvements in median survival can yet be attributed to chemotherapy. Few trials have measured quality of life, but symptomatic palliation rates may exceed objective response rates. Some low-toxicity regimens (such as those based on infusional 5-FU) yield response rates as high as some more toxic combinations.

CONCLUSIONS

Many early trials significantly overstate the efficacy of chemotherapy for patients with pancreatic cancer, apparently due to flexibility of response criteria. However, useful symptomatic palliation may occur even without an objective partial response. It is possible that slow resolution of the desmoplastic component of these tumors may underestimate tumor killing. Thus, quality of life is an important parallel endpoint (with survival and response) in chemotherapy trials in this disease.

Treatment of colorectal cancer: hepatic metastasis

Almost one-third of patients dying from colorectal cancer have tumor limited to the liver. Systemic chemotherapy is the appropriate palliative management of patients with metastases to the liver and other sites. For many patients with isolated hepatic metastases, systemic chemotherapy is also the most appropriate treatment. However, results with systemic chemotherapy indicate that one-third or less of patients will respond to such treatments, and long-term survival is rare. In this report we provide information concerning the natural history of colorectal hepatic metastases, followed by the expected benefits with systemic chemotherapy. This information provides background for the regional therapeutic strategies of surgical resection, cryosurgery, and hepatic artery chemotherapy. We discuss the selection factors appropriate for such treatments, morbidity and mortality, and the potential long-term benefits of such approaches. The last section focuses on surgical considerations in hepatic resection and hepatic artery chemotherapy.

Randomized trial of 5-fluorouracil and high-dose folinic acid with or without alpha-2B interferon in advanced colorectal cancer

We evaluated the role of low-dose alpha-2b interferon, added to chemotherapy, for advanced colorectal cancer; we randomized patients, to either a combination chemotherapy of 5-fluorouracil (5-FU) and high-dose folinic acid (HDFA) or the same regimen plus interferon. Between January 1990 and March 1992, 100 untreated patients (PTS) with advanced colorectal cancer, 53 men and 47 women, with an ECOG performance status (PS) of < or = 3, were randomized to either HDFA 200 mg/m2 iv bolus and 5FU 370 mg/m2 in 15-min iv infusion days 1-5 every 4 weeks (arm A), or the same chemotherapy plus IFN 3 x 10(6) IU subcutaneously three times a week in chemotherapy intervals (arm B). A total of 97 PTS are evaluable for response, toxicity, and survival; 3 PTS are not evaluable in arm B for major protocol violations. PTS characteristics were well balanced in both arms for age (median, 64 years), disease-free survival, and disease site. ECOG PS was 0 in 28% of PTS in arm A and in 13% in arm B. Response rates were as follows: arm A, 40%; and arm B, 23%. Median time to failure was as follows: 10.2 months arm A versus 9 months arm B. Median survival was as follows: 13.3 months arm A versus 10.9 months arm B. Grade 3 haematological toxicity was 9% of PTS in both arms. Gastrointestinal toxicity was as follows: 17% arm A versus 22% arm B. The cost of drugs expressed per m2/month was $60 in arm A and $390 in arm B. The results show that IFN at the schedule and doses employed adds no benefit to the combination of 5FU/HDFA.

Current treatment modalities in advanced colorectal carcinoma

Several biochemical and immunological substances are currently being tested for their efficacy in the treatment of advanced colorectal cancer, the second-most malignant disease in the western world. Presently, a combination of 5-fluorouracil (FU) and the biochemical modulator folinic acid is considered to be the standard treatment for this malignancy, with a median response rate of 30%. A recent multi-analysis of phase III trials with methotrexate and FU versus FU alone has demonstrated a statistically significant doubling of the response rate as well as a significant survival advantage for the combination. So far, other biochemical or immunological modulators of FU have not shown a significant advantage regarding response or survival. Several new drugs such as tegafur, thymidilate synthase inhibitors, trimetrexate, or topoisomerase-I-inhibitors have been tested with promising results in preclinical and early clinical settings. While local treatment such as hepatic artery infusion has become safer, it is still more toxic than systemic treatment and showed a significant improvement of response but no survival advantage. Since all treatment strategies in advanced colorectal cancer are still palliative, quality of life is a more important endpoint in clinical trials.

Evaluation of 96-hour infusion fluorouracil plus cisplatin in combination with alpha interferon for patients with advanced squamous cell carcinoma of the head and neck: a Southwest Oncology Group study

BACKGROUND

Recurrent cancer of the head and neck after primary therapy is almost always fatal. The combination of 5-fluorouracil (5-FU) and cisplatin is considered the best available therapy but complete response rates remain too low to affect survival. This study was designed to evaluate the complete response rate and toxicity of 5-FU, cisplatin, and alpha-interferon (alpha-IFN) in patients with recurrent or metastatic squamous cell carcinoma of the head and neck (SCCHN).

METHODS

Fifty eligible patients with recurrent or metastatic SCCHN and no prior chemotherapy (40 men, 10 women; age range, 26-77 years; median, 59 years; 82% white; 88% had prior surgery and 92% had prior radiation therapy) were treated every 21 days with 96-hour infusion of 5-FU 1000 mg/m2/day; cisplatin 100 mg/m2, day 1; and alpha-IFN 5 x 10(6) units/day, days 1-4.

RESULTS

One hundred fifty-seven courses of chemotherapy were administered, with a median of three courses. Thirty-seven patients experienced Grade 3 or 4 toxicity. Of the 17 patients with Grade 4 toxicity; 12 had hematologic toxicity, 3 stomatitis, and 2 vomiting. Two additional patients died of myelosuppression-related sepsis. Of the 50 patients, 3 (6%) achieved a complete response, five (10%) had a partial response, 3 (6%) had unconfirmed response (1 complete and 2 partial), 10 (20%) had stable disease, 17 (34%) progressed, and 12 (24%) were considered nonresponders owing to early death (6) or inadequate assessment (6). The median survival was 5 months.

CONCLUSION

The complete response rate of patients with recurrent or metastatic SCCHN treated with 5-FU, cisplatin, and alpha-IFN does not appear to be superior to that observed for 5-FU and cisplatin. Alpha-interferon appears to augment hematologic and gastrointestinal toxicities associated with this combination.

Role of adjuvant therapy in surgically resected colorectal carcinoma

An important advance in cancer treatment has been made in recent years with the finding that adjuvant therapy can significantly improve the survival of patients with colorectal cancer. In patients with resected lymph node-positive colon carcinomas (TNM stage 3), adjuvant 5-fluorouracil and levamisole produced an unequivocal survival advantage that established this combination as the standard of clinical practice. Given that biochemical modulation of fluorouracil by leucovorin can increase response rates in advanced disease, this combination is undergoing evaluation as an adjuvant treatment. Preliminary results indicate that 5-fluorouracil and leucovorin are effective in reducing disease relapse; however, the effect of this regimen on patient survival rates awaits extended follow-up. In the treatment of stages 2 and 3 rectal cancer, significant reductions in local recurrence and death rates have been achieved with the combination of 5-fluorouracil and radiation therapy. Immunologic approaches and newer chemotherapeutic agents may further improve patient outcome and are under investigation, as are efforts to reduce the toxic effects of cancer chemotherapy. Increased understanding of the biology of these diseases is likely to yield prognostic markers capable of identifying subgroups of earlier stage patients at high risk of disease relapse who may also benefit from adjuvant therapy.

Thymidine phosphorylase mediates the sensitivity of human colon carcinoma cells to 5-fluorouracil

Interferon-alpha (IFN alpha) potentiates the antitumor activity of 5-fluorouracil (FUra) in colon cancer in vitro, in vivo, and clinically. A likely mechanism for this action is the induction by IFN alpha of thymidine phosphorylase (TP), the first enzyme in one pathway for the metabolic activation of FUra to fluorodeoxyribonucleotides. To test this hypothesis, an expression vector containing the TP cDNA was transfected into HT-29 human colon carcinoma cells. Five stable transfectants were selected and analyzed. All showed increased sensitivity to FUra cytotoxicity, ranging from a 2-fold to a 19-fold decrease in the IC50 for FUra, compared to wild-type cells. Levels of TP mRNA, protein, and enzyme activity were elevated in the transfectants, and there was a significant correlation between the relative increase in sensitivity to FUra and both the increase in both TP mRNA levels and TP activity. Transfected cells exhibited increased formation of FdUMP, but not the ribonucleotides FUDP and FUTP, from FUra when compared to wild-type cells. The changes in TP activity, FdUMP formation, and FUra sensitivity in the transfected cells were comparable with those seen after treatment of wild-type cells with IFN alpha. These studies provide direct evidence for the role of TP in mediating the sensitivity of colon carcinoma cells to FUra, and further support the importance of the induction of TP in the biomodulating action of IFN alpha on FUra chemosensitivity.

CPT-11 (irinotecan) in the treatment of colorectal cancer

Colorectal cancer is one of the most common cancers in the Western World. Although 50% of patients are cured by surgery alone, the outcome is poor in high-risk patients (Dukes stages B2 and C) despite adjuvant chemotherapy with 5-fluorouracil (5-FU)-based regimens. CPT-11 (irinotecan) is a promising new agent for the treatment of colorectal cancer with a unique mechanism of action. CPT-11 is a DNA topoisomerase I inhibitor, which has not demonstrated susceptibility to the P-glycoprotein-mediated multidrug-resistant phenotype. Phase II studies with CPT-11 have demonstrated definite activity against colorectal cancer in both chemotherapy-naive and pretreated patients (response rates of 15-32% observed) even with clinical evidence of resistance to 5-FU. The response rate appears to be consistent, reproducible and equivalent to that achieved with 5-FU plus folinic acid in chemotherapy-naive patients.

Continuous infusion of 5-fluorouracil with alpha 2b interferon for advanced colorectal carcinoma

Thirty patients with symptomatic colorectal carcinoma were commenced on treatment with 5-fluorouracil (2.5 g week-1) administered by continuous intravenous infusion and alpha 2b interferon (3 x 10(6) U s.c. three times a week). Six out of 30 patients (20%) achieved a partial response. Three patients (10%) had stable disease and 21 patients (70%) progressed on treatment. Twenty patients (67%) completed ten or more weeks of treatment. In nine patients, treatment was withdrawn after 2-9 weeks because of disease progression or death. One patient's treatment was interrupted by emergency surgery. The median survival for all patients was 210 days (7 months). The principal side-effects were oral mucositis (12/30 patients), nausea (8/30 patients) and transient diarrhoea (4/30 patients), and initial constitutional symptoms due to alpha 2b interferon. The combination of low-dose continuous infusional 5-fluorouracil and low-dose alpha 2b interferon is well tolerated but has no obvious advantage over alternative infusional regimens using 5-fluorouracil as a single agent.

Potential uses of interferon alpha 2 as adjuvant therapy in cancer

BACKGROUND

The purpose of this study was to provide an overview of the potential uses of adjuvant interferon (IFN) therapy for resected solid tumors at high risk for postsurgical relapse.

METHODS

A MEDLINE search (1970-1994) of the English-language literature for original articles, reviews, and abstracts addressing IFN use in the adjuvant setting together with the authors' collective experience formed the basis for this review.

RESULTS

The use of adjuvant IFN-alpha has been studied most extensively in conjunction with the treatment of melanoma. Fewer data are available on IFN-alpha use for the treatment of other solid tumors. In melanoma, there is evidence from Intergroup trials (Eastern Cooperative Oncology Group and World Health Organization) that IFN-alpha 2a given for 1-3 years prolongs the interval to relapse and may have a survival benefit. Trials of adjuvant IFN, with and without chemotherapy, are ongoing in the treatment of renal cell carcinoma and colorectal adenocarcinoma. Its value in the treatment of osteosarcoma and high-grade astrocytoma is unknown.

CONCLUSIONS

The use of IFN in the adjuvant setting is an exciting area of medical and surgical oncology and has the potential to prolong the time to relapse and to increase survival of patients with melanoma. Its role in the adjuvant therapy of other solid tumors remains to be defined.

Treatment of advanced colorectal cancer with 5-fluorouracil and interferon-alpha: an overview of clinical trials

5-Fluorouracil (5-FU) is the most active single agent for treatment of advanced colorectal cancer, although objective responses occur in only 20% of patients, and there seems to be no impact on overall survival. Experimental findings suggesting that interferon-alpha (IFN-alpha) enhances 5-FU cytotoxicity have stimulated an increasing number of clinical trials to evaluate the therapeutic potential of this combination. This article summarises the possible mechanisms of interaction of 5-FU and IFN-alpha, and provides an overview of the current status of this approach in advanced colorectal cancer. A computerised (Medline) and manual search were performed to identify all trials using 5-FU and IFN-alpha for the treatment of advanced colorectal cancer published in the English literature between 1960 and 1994. Information abstracted included treatment regimen, number of patients, pretreatment status, complete and partial remissions, remission duration, overall survival, and toxicity. A total of 417 patients were enrolled in 16 trials using different regimens of 5-FU and IFN-alpha, and double modulation of 5-FU with leucovorin (LV) and IFN-alpha was investigated in nine trials involving 332 patients. The mean overall response rate in these phase II trials was only 31% (range 3-76) and 35% (range 0-54), respectively. Early results of six prospectively randomised studies of 5-FU or 5-FU/LV +/- IFN-alpha also did not suggest a significant enhancement of the antitumour effectiveness with the addition of IFN-alpha. There is increasing evidence, however, that administration of IFN-alpha along with 5-FU enhances toxicity. Because of their modest therapeutic index, currently employed regimens of 5-FU +/- LV plus IFN-alpha cannot be recommended for routine use at the present time. The combination of 5-FU plus LV represents an equally effective and less expensive alternative. Nevertheless, there is still hope that further attempts to elucidate the complex mechanisms of this potentially synergistic drug combination will allow the rational design of regimens with a superior therapeutic index.

Pharmacokinetic interaction of 5-fluorouracil and interferon alpha-2b with or without folinic acid

The purpose of this study was to evaluate a potential pharmacokinetic (PK) interaction between fluorouracil (5-FU) and the biomodulating agent interferon alpha (IFN-alpha) in patients with metastatic colorectal carcinoma. 5-FU was applied as an intravenous bolus injection of 750 mg m-2 weekly and IFN-alpha 2b (IFN) 5 MU was injected 3 times weekly (TIW) subcutaneously. In the first study, 13 patients were treated by this schedule, 5-FU plasma levels were determined by HPLC on day (d) one as baseline before starting IFN; the analysis was repeated at the second or third cycle of 5-FU administration 1 hour after the last IFN injection respectively. In the second study, 10 patients additionally received folinic acid (FA) 200 mg m-2 as a short time infusion immediately before 5-FU, and a third analysis of FU kinetics was performed in order to compare the influence of a double modulation of IFN and FA to IFN alone. Combination of 5-FU and IFN resulted in a significant increase of the AUC of 5-FU (80%) and the fictive initial concentration (C0, 65%) obviously caused by a reduction of 5-FU clearance by 50%. However, when FA was added to this schedule, no significant changes of FU kinetics compared to 5-FU alone could be documented. Finally, in two pilot patients 5-FU 750 mg was given as a continuous infusion (CI) over 5 days and IFN 5 x 10(6) u was added daily from d2 to d5.(ABSTRACT TRUNCATED AT 250 WORDS)

Different dose regimens of 5-fluorouracil and interferon-alpha in patients with metastatic colorectal carcinoma

Three different 5-fluorouracil (5-FU)-interferon-alpha-2b (IFN)-containing regimens were designed for treatment of patients with advanced colorectal cancer. 87 patients with a Karnofsky index > or = 70 were included in three sequential non-randomised phase II trials. Regimen A consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5 followed by weekly 1-h intravenous infusions until week 8. IFN (5 MU) was given subcutaneously on days 1, 3 and 5 followed by injections (9 MU) every second day until week 8. The cycle was then repeated. Regimen B consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5 followed by 5-min intravenous injections on days 12 and 19. IFN (3 MU) was given subcutaneously on days 1-5 followed by injections (5 MU) on days 11-13 and 18-20. The cycle was repeated every fourth week. Regimen C consisted of 5-FU (750 mg/m2/day) given as a continuous infusion on days 1-5. IFN (3 MU) was given subcutaneously on days 1-5. The cycle was repeated every third week. The objective response rates (complete response (CR) and partial response (PR)) after approximately 4 months of therapy or longer were as follows: regimen A (n = 27) 22% (2 CR, 4 PR), regimen B (n = 33) 42% (4 CR, 10 PR) and regimen C (n = 27) 22% (1 CR, 5 PR). The corresponding response figures for previously untreated patients were regimen A 50%, regimen B 64% and regimen C 38%. Response durations varied from a few weeks up to 142 + weeks. Toxicities were generally mild and reversible, and the treatments were convenient for the patients and cost effective since the 5-day infusions could be given by a portable pump without hospitalisation. Our results are in agreement with those of others showing that 5-FU/IFN combinations can be highly effective in advanced colorectal cancer, and that a number of factors such as doses, dose intensities, infusion rates and timing of the two drugs may be crucial for the anti-tumour activity of this drug combination.

Dermatological toxicity from chemotherapy containing 5-fluorouracil

5-Fluorouracil (5-FU) is an antimetabolite frequently used in the treatment of cancer. The most common adverse reactions are acute gastrointestinal effects and bone marrow suppression while neurological, ocular and dermatological toxicities are unusual. Several cutaneous manifestations can be found. They are hyperpigmentation, maculo-papular eruption and palmar-plantar erythrodysesthesia (PPES) promptly reversed with discontinuation of 5-FU. The etiopathogenesis of such manifestations is still unknown particularly as regards PPES, but it has been postulated that the local drug accumulation secondary to different scheduling (continuous infusion instead of bolus infusion), the total amount of drug, alcoholism, local trauma, increased blood flow could be responsible for them. In this study we have reported 10 cases of dermatological toxicity (1 of these had PPES) observed from January '91 to December '93 in 81 patients treated with bolus injection of 5-FU containing combination chemotherapy.

Phase II trial of 5-fluorouracil and alpha-2b interferon in patients with hormone-refractory metastatic prostate cancer

OBJECTIVES

Metastatic prostate cancer remains a disease with no effective therapy. We treated 13 patients with hormone-refractory metastatic prostate cancer with 5-fluorouracil (5-FU) and alpha-2b interferon. Our objectives were to determine the response rate and toxicity of recombinant alpha interferon and 5-FU in patients with hormone-refractory metastatic prostate cancer.

METHODS

Patients with progressive hormone-refractory metastatic prostate cancer with adequate hematologic and renal function underwent baseline bone scans, computed tomographic (CT) scans of abdomen and pelvis, and measurement of prostate-specific antigen (PSA). Therapy consisted of a 5-day loading course of 5-FU at 500 mg/m2 with alpha-2b interferon 9 million units subcutaneously 3 times weekly followed by weekly 5-FU and alpha interferon 3 times per week.

RESULTS

When PSA was used as a response parameter with modified National Prostatic Cancer Project (NPCP) criteria, no objective responses were seen. Using NPCP criteria alone, 5 patients had stable disease. Post-therapy PSA values increased from baseline in 8 of 11 patients (2% to 72%) and declined in 3 patients (3% to 16%). Frequent dosage modifications were required with the dose intensity of 5-FU and alpha interferon of 57% and 58%, respectively. Toxicity was significant, with 31% of patients having grade 3 to 4 mucositis and 46% grade 3 to 4 fatique.

CONCLUSIONS

5-FU and alpha interferon, when administered at the dosage and schedule utilized in this study, have no clinically significant activity and are associated with unacceptable toxicity in patients with metastatic prostate cancer. The role of PSA as an indicator of response remains unclear.

5-Fluorouracil-interferon-alpha 2b adjuvant treatment of Dukes C colorectal cancer

PURPOSE

To determine whether interferon: alpha 2b can improve results of 5-fluorouracil adjuvant treatment of Dukes C colorectal cancer patients, we compared the outcome of patients receiving a fluorouracil-interferon combination to that of historic controls treated with fluorouracil alone.

METHODS

Fifty-seven Dukes C colorectal cancer patients were given 5-fluorouracil-interferon-alpha 2b adjuvant treatment from October 1986 to September 1990. The results were compared with those obtained in 51 consecutive patients treated at the same institutions with 5-fluorouracil (5-FU) alone (used at the same doses and schedule) between 1983 and 1986. The main prognostic variables were similar in the two groups.

RESULTS

No life-threatening toxicity occurred in either group. The addition of interferon (IFN) slightly impaired tolerance to the treatment; however, the dose of IFN had to be reduced only in five patients and discontinued in one patient. Grade 3 and 4 myelotoxicity was rare and not substantially different in the two groups. Interferon-related side effects (fever, flu-like syndrome, malaise, etc.) were frequent, but, in general, mild or moderate. At the time of this analysis (July 1992), median follow-up was 49 (range, 20-70) months in the group of patients treated with 5-FU+IFN, and 86 (range, 68-103) months in the group receiving 5-FU alone. There were 17 recurrences and 15 cancer-related deaths among patients receiving combined treatment, and 27 deaths in the group treated with 5-FU alone. Both five-year relapse-free survival (65 percent vs. 47 percent; P = 0.043) and cause-specific survival (64 percent vs. 46 percent; P = 0.038) were significantly better in the patients receiving combined treatment. After correction for the influence of prognostic pretreatment variables, 5-FU+IFN again afforded a significant advantage in terms of both relapse-free (P < 0.01) and overall survival (P < 0.001).

CONCLUSION

5-FU-IFN-alpha 2b treatment seems to improve the prognosis in Dukes C colorectal cancer patients.

Double modulation of 5-fluorouracil by high-dose leucovorin and interferon alpha 2b in advanced colorectal cancer: a phase I and a phase II study of weekly administration

In an attempt to evaluate the feasibility of 5-fluorouracil (FU) treatment modulated by (R,S)-leucovorin (LV) and interferon alpha (IFN alpha) in patients with advanced colorectal cancer, we conducted a phase I trial with increasing doses of subcutaneous IFN alpha (3 x 1 x 10(6) U, 3 x 3 x 10(6) U, 3 x 3 x 10(6) U, 3 x 5 x 10(6) U and 3 x 10 x 10(6) U/week) and 500 mg/m2 LV i.v. as a 2-h infusion with 600 mg/m2 FU i.v. as a midpoint injection. Unacceptable side-effects occurred in all 3 patients at the highest dose level of IFN alpha, while toxicity was tolerable at 3 x 5 x 5 x 10(6) U IFN alpha/week. Thus, this dose was defined as the maximal tolerable dose for IFN alpha in combination with FU and LV. In a subsequent phase II study a total of 83 treatment courses (median: 2.8, range: 2-10) were administered to 30 evaluable patients. Side-effects were acceptable with no WHO grade IV toxicities. Grade III toxicities consisted in thrombopenia (2/30), stomatitis (2/30), diarrhoea (3/30) and nausea/vomiting (4/30). After a median observation time of 17 months (range: 8-22 months), no complete remission was observed and 9 patients experienced a partial response lasting for a median of 6.6 months (range: 3-13+ months), for an overall response rate of 30% (95% confidence interval: 15%-49%). These results show that the described regiment of FU doubly modulated by LV and IFN alpha is active in colorectal cancer and can be safely administered in an out patient setting with acceptable toxicity. Thus, this regimen is suitable to be used for further evaluation in clinical trials.

New targets for pyrimidine antimetabolites in the treatment of solid tumours. 1: Thymidylate synthase

Thymidylate synthase forms the target for anticancer therapy with fluoropyrimidines. Anticancer activity can be increased by the use of different modulators of fluoropyrimidine metabolism, which lead to an enhanced inhibition of thymidylate synthase. In vitro and in vivo studies with fluoropyrimidines and two of these modulators, folinic acid (leucovorin) and interferon, are summarized. The promise of these preclinical results is reflected by the response data of several clinical trials. The biochemical effects of these modulators are described and illustrated by the fluoropyrimidine-mediated inhibition of thymidylate synthase in tumour samples, which is clearly enhanced by folinic acid. The regulation of thymidylate synthase synthesis may also be crucial for total blockade of thymidylate synthase activity. This regulation may be influenced by interferon-gamma. Although the addition of modulators increases the activity of fluoropyrimidines at the level of thymidylate synthase, most solid tumours, especially colorectal carcinomas, are resistant to these combinations. For this reason, new, more potent inhibitors of thymidylate synthase have been developed, the antifolates. Preclinical data show that some of these compounds have good antitumour activity, but they still have to prove their value in the clinic. These two approaches, the use of modulators and new compounds, have shown activity preclinically and the extension of these findings to clinical studies stresses the importance of thymidylate synthase as a target in fluoropyrimidine therapy of solid tumours.