Continuous venous infusion 5-fluorouracil and interferon-alpha in pancreatic carcinoma

Blood flow via an aberrant internal carotid artery within the tympanic cavity is a rare pathogenic embryonic variation causing pulsatile tintinus and a vascularized tympanum. CT-scan provides the diagnosis. MRI and 3D time-of-flight MRA appear ideal for exploring aberrant flow both for diagnostic purposes and to establish the vascular morphology.     

Phase II trial of 5-fluorouracil, interferon-alpha and continuous infusion interleukin-2 for patients with metastatic renal cell carcinoma

BACKGROUND: This study was designed to evaluate the efficacy and toxicity of the combination of 5-fluorouracil, interferon-alpha, and interleukin-2 for patients with metastatic renal cell carcinoma. METHODS: Previously untreated patients with a Zubrod performance status of < or =2; adequate cardiac, pulmonary, and renal function; and absence of brain metastases were eligible. One course of therapy was 28 days. 5-fluorouracil was administered at a dose of 600 mg/m2/day as a continuous infusions on Days 1-5. Interleukin-2 also was administered as a continuous infusion on Days 1-5 at a dose of 2 million Roche U/m2/day. Interferon-alpha was given as a daily subcutaneous injection of 4 million U/m2/day. RESULTS: Fifty-five patients were enrolled in the trial and 52 were evaluable for response. All patients experienced fever and flu-like symptoms. Grade 3 or 4 nonhematologic toxic effects included hypertension (48%), dermatitis (12%), stomatitis (11%), and altered mental status (9%). There was one toxic death. Four complete responses and 12 partial responses were observed for a total response rate of 31% (95% confidence interval, 18-46%). The survival of responding patients was significantly better than that of nonresponding patients. The improvement in survival was even more significant when comparing patients with at least stable disease with those who progressed through treatment. CONCLUSIONS: The three-drug combination described in this study demonstrates activity. However, it appears to be more toxic than other regimens with similar response rates and cannot be recommended for standard practice. Changing the interleukin-2 route to subcutaneous administration may permit more continuous administration with less toxic effects.     

Improved survival in patients with advanced colorectal carcinoma failing 5-fluorouracil who received irinotecan hydrochloride and have high intratumor C-fos expression

INTRODUCTION: We optimized the technique of contrast-enhanced Magnetic Resonance Angiography (MRA) with a .5 T superconductive magnet. MATERIAL AND METHODS: Forty patients with normal blood pressure and heart rate gave their informed consent to MRA studies with contrast agent administration. The carotid arteries were studied in 10 patients, the pulmonary arteries in 10, the thoracic aorta in 10 and the abdominal aorta and renal arteries in 10. All the examinations were performed with a .5 T superconductive magnet (Philips T5) acquiring 3D T1-weighted GE sequences with contrast agent administration. The parameters were: TR/TE/FA 13 ms/4 ms/60 degrees; 256 x 256 MA; 2 mm slice thickness; 1 NEX. The contrast agent was administered with an automatic injector (.2 mmol/kg at 1.5 flowrate) after a bolus test to evaluate circulation time. The images were studied by a radiologist rating artery visualization as "good" or "poor" on a multiple choice card. The signal-to-noise ratio was evaluated using regions of interest positioned on the examined vessels (signal) and muscles (noise). RESULTS: The mean start delay was 12.2 s for the abdominal aorta, 10.3 s and 8.7 s for the thoracic aorta and pulmonary arteries, and 10.3 for the carotid arteries. Fifty-eight of 70 vessels were well visualized and 12 were poorly visualized. The signal-to-noise ratio exceeded 1 in all districts. CONCLUSIONS: Our experience shows that enhanced MRA provides diagnostic images of body arteries even at .5 T.     

Apoptosis in cultured human colon cancer cells induced by combined treatments with 5-fluorouracil, tumor necrosis factor-alpha and interferon-alpha

An experimental study of Allergan's Oxysept Comfort system was performed by measuring the slight reddish hue that appears in the disinfecting solution, indicating to the users that their lenses are again ready to be worn. The temporal evolution of the color of the solution has been measured under standardized conditions and analyzed in the CIELAB system, from the perspective of the typical threshold discrimination of the human eye. Color differences between neutralized and non-neutralized solutions occurred in an appropriate direction of the color space to enhance discrimination and were clearly perceptible by normal observers (greater than 9.7 +/- 1.2 CIELAB units). Colorimetric analyses have been used to draw conclusions regarding observers with defective color vision. The color of the solution changes abruptly, approximately 25 min after the neutralization process begins, and remains nearly constant after about 60 min, this agreeing well with the temporal evolution of the hydrogen peroxide concentration.     

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.     

Treatment of advanced colorectal cancer with folinic acid and 5-fluorouracil in combination with cisplatinum

51 patients with metastatic colorectal cancer (stage Dukes D) were treated with intravenous (i.v.) infusion on days 1, 3, 5, 8 and 16 with folinic acid (200 mg/m2) and 5-fluorouracil (600 mg/m2), and on days 1, 8 and 16 with cisplatinum (25 mg/m2 i.v.); cycles were repeated every 4 weeks. All 51 patients were evaluable for toxicity and response criteria. 26 patients had objective responses (3 complete responses, 5.9%; 23 partial responses, 45.1%), relative risk 51% (95% confidence intervals 36.7-65.0%). Response duration ranged from 4 to 28.0 months (median 16.8). Overall median survival of all patients included was 14.7 months (range 3.0-33.0). Toxicity of WHO grade III, requiring dose reduction, occurred in 9 (18%) patients. The regimen described here appears to be active, safe and well tolerated for treatment of patients with advanced colorectal cancer.     

A phase II trial of weekly infusional 5-fluorouracil in combination with low-dose leucovorin in patients with advanced colorectal cancer

We examined 59 breast cancers for p53 and bcl-2 protein expression by immunohistochemistry. The results were correlated with Ki-67 immunostaining. p53-negativity was noted in 40 cases and the remaining 19 tumours were p53-positive. Thirty-six tumours showed strong expression of bcl-2 and in 23 no staining for this protein was observed. We found statistically significant reverse correlation between expression of p53 and bcl-2 in majority of carcinomas: 31 cases were bcl-2 positive and p53-negative, and 14 tumours were bcl-2-negative and p53-positive. Six carcinomas showed no nuclear staining for Ki-67 and in the remaining 53 the percent of cancer cells positive for Ki-67 ranged from 1 to 60 (mean: 14.6). In these 53 cases we found that bcl-2-positive tumours were characterized by lower proliferation than bcl-2-negative tumours, the mean value of Ki-67 immunostaining being 10.7% and 23.0%, respectively. p53-negative tumours showed lower proliferation than p53-positive tumours: mean Ki-67 index was 10.2% and 23.9%, respectively. We conclude that immunohistochemically detected p53 and bcl-2 proteins show a significant inverse relationship in majority of breast carcinomas and their expression correlates with tumour proliferation (Ki-67 immunostaining).     

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

Based on experimental findings suggesting that 5-fluorouracil (FUra) may have different mechanisms of action depending on the schedule of administration, we generated the hypothesis that biochemical modulation of this fluoropyrimidine should be schedule specific. We thus tested the activity of a hybrid regimen consisting of two biweekly cycles of FUra bolus (600 mg/m2) modulated by pretreatment (24-h interval) with methotrexate (200 mg/m2), alternating with a 3-week continuous infusion of FUra (200 mg/m2/day) modulated by low-dose (6S)leucovorin (20 mg/m2 bolus weekly). Thirty-three consecutive patients with advanced measurable colorectal cancer and no prior therapy for metastatic disease entered the study from February 1992 to August 1993. They were treated with two biweekly cycles of FUra bolus (600 mg/m2) preceded by (24-h interval) methotrexate (200 mg/m2), alternating with a 3-week continuous infusion of FUra (200 mg/m2/day) modulated by low-dose (6S)leucovorin (20 mg/m2 bolus weekly). The median Eastern Cooperative Oncology Group performance status was 1; the liver was the only metastatic site in 17 patients. Treatment outcome was evaluated by computed tomographic scan in all patients, except for two. Three complete and 13 partial responses were obtained among these 33 patients (response rate, 48%; 95% confidence limits, 31-66%). Performance status (Eastern Cooperative Oncology Group) influenced clinical response. The combined complete response and partial response rate was 69%, 33%, and 25% in patients with an Eastern Cooperative Oncology Group performance status of 0, 1, and 2, respectively (chi2, 4.6, P = 0.032, two-tailed Mantel test for trend). After a median follow-up time of 26 months, 10 patients are still alive. The median progression-free survival and overall survival were 9.5 and 20.2 months, respectively. No toxic deaths or grade 4 toxicity occurred. The incidence of grade 3 toxicity per patient in any cycle was: mucositis 6%, diarrhea 3%, and vomiting 3% for the bolus part and 21%, 3%, and 6%, respectively, for the continuous infusion part of the regimen. Hand-foot syndrome occurred in 27% of the patients treated with the continuous infusion regimen.     

Phase II study of combined levamisole with recombinant interleukin-2 in patients with advanced malignant melanoma

Adoptive immunotherapy (AI) with interleukin-2 (IL-2) and lymphokine-activated killer cells (LAK) is an antineoplastic modality in which immune-activated cells are administered to a host with advanced cancer in an attempt to mediate tumor regression. Levamisole (LEV), an immune stimulant, has been suggested to have therapeutic effectiveness in a variety of cancers. After a phase I trial of recombinant IL-2 plus LEV, a phase II trial of this combination was conducted in patients with advanced malignant melanoma. Nineteen patients were entered in the trial. They received IL-2 at 3 x 10(6) U/m2 subcutaneously daily x 5 plus LEV 50 mg/ m2 orally three times daily (p.o. t.i.d.) x 5. Patients were reevaluated at four-week intervals. None of the patients achieved a partial or complete regression (PR, CR). The median time to treatment failure (refusal, progression, or off study due to toxicity) was 56 days. Grade IV toxicities included vomiting (3 patients), lethargy (1 patient), and musculoskellar pain (1 patient). This regimen is not recommended for further testing in patients with advanced malignant melanoma.     

Phase I trial of subcutaneous recombinant human interleukin-12 in patients with advanced renal cell carcinoma

Patients with advanced renal cell carcinoma were treated in a Phase I trial with escalating doses of recombinant human interleukin-12 (rHuIL-12) given on days 1, 8, and 15 of each 28-day cycle. Treatment in the initial dose scheme consisted of a fixed dose with dose levels of 0.1, 0.5, and 1.0 microg/kg given to cohorts composed of three or six patients. On the basis of the toxicity profile, a second scheme (up-titration) was undertaken wherein rHuIL-12 was escalated for each patient from week 1 to week 2, to a target dose given week 3 and thereafter; cohort target dose levels were 0.5, 0.75, 1.0, 1.25, and 1.5 microg/kg. Fifty-one patients were treated: 32 (63%) had prior cytokine therapy and 19 (37%) had received no prior systemic therapy. The maximum tolerated dose for the fixed dose scheme was 1.0 microg/kg. Dose-limiting toxicities included increase in transaminase concentration, pulmonary toxicity, and leukopenia. The most severe toxicities occurred with the first injection and were milder upon further treatment. With the up-titration dose scheme, the maximum tolerated dose was reached at 1.5 microg/kg, and dose-limiting toxicity consisted of an increase in serum transaminase levels. At the maximum tolerated dose of 1.5 microg/kg, serum IL-12 levels increased to a mean peak level of 706 pg/ml. Serum levels of IFN-gamma increased to a mean peak level of about 200 pg/ml at 24 h after the first maintenance dose of 1.5 microg/kg. The best responses were as follows: one patient had complete response, 34 patients were stable, 14 patients showed progression, and 1 patient was inevaluable. In conclusion, rHuIL-12 was relatively well tolerated when administered by s.c. injection. The recommended dose according to the up-titration schedule of rHuIL-12 (microg/kg) for Phase II trials was as follows: cycle 1, 0.1 (day 1), 0.5 (day 8), 1.25 (day 15); cycle 2 onwards, 1.25. Phase II trials of rHuIL-12 were initiated in previously untreated patients with renal cell carcinoma and in patients with melanoma.     

Modulation of 5-fluorouracil with methotrexate and low-dose N-(phosphonacetyl)-L-aspartate in patients with advanced colorectal cancer. Results of a phase II study

Methotrexate (MTX) and N-phosphonacetyl-L-aspartate acid (PALA) have been shown to modulate the cytotoxic effects of 5-fluorouracil (5-FU). A phase II study was initiated to evaluate the feasibility, toxicity and efficacy of PALA/MTX and 5-FU in patients with metastatic colorectal cancer. 26 patients received PALA 250 mg/m2 as an intravenous 15-min infusion plus MTX 200 mg/m2 as a 30-min intravenous (i.v.) infusion on day 1 and 5-FU 600 mg/m2 as i.v. push on day 2. Cycles were repeated every 14 days and the 5-FU dose was escalated in the individual patient in steps of 100 mg/m2 for the third, fifth and seventh cycle in the absence of toxicity. 7 patients had received prior 5-FU-based chemotherapy while 19 patients were chemotherapy naive. Objective responses occurred in 23% of patients (1 CR, 5 PR of which 2 were pretreated), no change in 13 patients (50%) and tumour progression (6 patients) or toxic death (one patient) in 27%. Responses lasted for a median of 7 months (range 6-9), the median time to progression was 4 months and median survival 13 months. Toxicity was mainly gastrointestinal with diarrhoea and mucositis, and severe or life threatening in only 3 patients. In 3 patients an increase in serum glucose levels occurred while being treated with PALA/MTX and 5-FU. 2 patients with insulin-dependent diabetes had a 33% increase in insulin requirement and 1 patient with dietary-controlled diabetes died due to a ketoacidotic coma. PALA/MTX/5-FU in this dose and schedule is active in patients with colorectal cancer. Hyperglycaemia may be a potential side-effect of PALA-containing regimens especially in patients with diabetes. Careful monitoring of serum glucose levels in these patients is indicated.     

Cellular interactions of 5-fluorouracil and the camptothecin analogue CPT-11 (irinotecan) in a human colorectal carcinoma cell line

CPT-11 (irinotecan) is a DNA topoisomerase I inhibitor active against metastatic colorectal carcinoma. We investigated, in a human colon carcinoma cell line, HT-29, the effects of CPT-11 and 5-fluorouracil (5FU) combinations. A strong synergism between CPT-11 and 5FU was observed after sequential exposure and only additivity or antagonism after simultaneous exposure. When cells were first exposed to 5FU, the product of cellular CPT-11 concentrations versus time (CxT) was 6895 +/- 1020 pmol x hr/10(6) cells, while it was 3875 +/- 121 pmol x hr/10(6) cells with CPT-11 alone (p < 0.01). The same phenomenon was observed with SN-38: 148.2 +/- 49.5 versus 83.4 +/- 23.6 pmol x hr/10(6) cells (p < 0.05). Consequently, the formation of protein-DNA complexes was 1.4 times greater with 5FU pretreatment than with CPT-11 alone (p = 0.03). Moreover, the incorporation of 5FU derivatives into DNA was multiplied by a factor of 1.5 24 hr after CPT-11 exposure. When cells were first incubated with CPT-11, the decrease in thymidylate synthase (TS) activity was identical to that obtained after 5FU exposure (1.09 to 0.023 pmol/min/mg protein), but this decrease persisted for 24 hr (0.014 pmol/min/mg protein) (p = 0.035). At the same time, a 1.8-fold increase in the incorporation of 5FU derivatives into DNA and a 2-fold increase in DNA-protein complex formation were evidenced. With the two sequential associations, we observed a persistent S-phase arrest, as compared with CPT-11 alone. These results suggest that CPT-11 and 5FU combinations are of clinical interest, and mechanisms of interaction between the two drugs seem to be multifactorial.     

5-Fluorouracil plus interferon alpha-2a compared to 5-fluorouracil alone in the treatment of advanced colon carcinoma: a multicentric randomized study

Biochemical modulation is one of the most interesting fields in cancer chemotherapy. Interferon-alpha (IFNalpha) is a cytokine that is able to influence the pharmacodynamics of 5-fluorouracil (5FU) through a number of mechanisms. With the aim of confirming some data emerging from the literature, we initiated a multicentric randomized study comparing the combination of 5FU and IFNalpha-2a with 5FU alone in the treatment of advanced or metastatic colon cancer. A group of 205 colon cancer patients (104 in the 5FU arm and 101 in the 5FU + IFNapha-2a arm) were included in the final intention-to-treat analysis. Rectal cancers were not considered eligible. All patients had measurable disease, were aged 75 years or less, had a Karnofsky index of at least 60 and had good bone marrow, renal, liver and cardiac functions. No previous chemo-immunotherapy was allowed. The treatment was 750 mg/m2 5FU (4 h i.v. infusion) on days 1 5 and then i.v. bolus weekly, starting from day 12, with or without IFNalpha-2a given s.c. three times weekly (starting dose 3 x 10(6) IU rising to 9 x 10(6) IU, if tolerated). Patients were treated until progression or, if responsive, for a maximum of 48 weeks and then observed for a period of 2 years. The primary end-point of the study was objective clinical response (OR); secondary parameters were time to progression, overall survival, and time to death after progression. WHO criteria were used for both clinical response and toxicity measurements. Dose reduction was planned a priori in the event of significant toxicity due to 5FU, IFNalpha-2a or both. Association between primary and secondary end-points and treatment was studied by univariate and multivariate analysis. Altogether, 47 patients achieved a documented response. A 25% OR was observed in the combination arm while a 21% OR was seen in the 5FU arm; this difference is not statistically significant (P = 0.6). Patients with a small tumour burden (below 5 cm2) showed a higher probability of response in both arms. Patients in the experimental arm had a higher but not statistically significant cumulative progression-free probability. Median survival was 47.1 weeks overall, while it was 43.7 and 48.5 weeks in the control and experimental arms, respectively. The combination was clearly more toxic than 5FU alone, leukopenia being the most frequent side-effect in the experimental arm and nausea and vomiting in the control arm. In conclusion these results are quite disappointing and 5FU + IFNalpha-2a can not be considered a standard treatment for advanced colon cancer.     

Phase I trial of a 5-day infusion of L-leucovorin plus daily bolus 5-fluorouracil in patients with advanced gastrointestinal malignancies

Increased Na+/H+ exchanger activity is associated with cellular hyperplasia. Cellular hyperplasia is an adaptive response to small-intestinal resection. Therefore, we hypothesized that the small-intestinal Na+/H+ exchanger activity increases in response to small-intestinal resection. Twenty-one-d-old, male Sprague-Dawley rats were randomly divided to receive either a 70% small intestinal resection (n = 59), or a mid-small intestinal transection (n = 49). Seven d postoperatively, the animals were killed and the Na+/H+ exchanger activity of the intestinal remnants was studied by a well validated brush border membrane vesicle technique. The initial rate of Na+ uptake in the presence of an outwardly directed pH gradient and the Vmax of the amiloride-sensitive Na+ uptake were significantly increased (p < 0.01 and p < 0.001, respectively) in the resection as compared with the transection remnants and to a greater magnitude in the distal as compared with the proximal remnants. Km values were not significantly different. The amiloride-sensitive Na+ uptake in the setting of various intravesicular pH was significantly greater (p < 0.001) in the distal resection as compared with the distal transection remnants, with points of enhanced Na+/H+ exchanger activity of intravesicular pH 6.62 and 6.87, respectively. The presence and activation of the Na+/H+ exchanger's internal modifier site was confirmed by demonstrating the effect of intravesicular pH on Na+ efflux. The present study demonstrates an up-regulation of intestinal Na+/H+ exchange activity in a small-bowel resection model in the weanling rat.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparison of 5-fluoro-2'-deoxyuridine with 5-fluorouracil and their role in the treatment of colorectal cancer

Despite more than 30 years of intensive studies on new drugs against advanced colorectal cancer, the fluoropyrimidines remain the drugs of choice for systemic treatment and for hepatic artery infusion (HAI). This overview describes new developments in advanced colorectal cancer chemotherapy, providing a rationale for more effective use of the fluoropyrimidines, with biochemical modulation, scheduling or by revealing biochemical mechanisms of action that correlate with antitumour activity. In human colorectal cancer cell lines and various animal tumour model systems 5-fluoro-2'-deoxyuridine (FdUrd) is more effective than 5-fluorouracil (5-FU). Comparably, FdUrd's modulation by leucovorin (LV) is more potent than 5-FU. In animal studies it is shown that intermittent high-bolus administration of FdUrd generates better antitumour activity, compared with equal toxic doses or any other schedule of 5-FU. These effects are related to prolonged-thymidylate synthase (TS) inhibition and the prevention of TS induction, rather than RNA incorporation. Preclinical studies with modulators such as N-phosphonacetyl-L-aspartate (PALA), WR-2721, mitomycin C and platinum derivatives provide a rationale for clinical use in the future. The first choice systemic chemotherapy of patients with advanced colorectal cancer remains 5-FU combined with LV. Some improvement in therapeutic efficacy has been achieved with locoregional HAI. In randomised studies HAI FdUrd improves the quality of life and survival as compared with optimal systemic therapy. Chronomodulation decreases toxicity, allowing dose intensification, while modulators such as LV or dexamethasone increase survival of patients treated with HAI FdUrd to 86% after 1 year. In conclusion, the clinical use of FdUrd has not been fully explored. Intermittent high-dose FdUrd, chronomodulation together with the use of modulators or drugs focused on prolonged TS inhibition, should be studied in large randomised studies.     

Phase II study of continuous intravenous infusion of recombinant interleukin-2 in patients with advanced renal cell carcinoma

BACKGROUND: The goal of this study was to evaluate the therapeutic efficacy and toxicity of recombinant interleukin-2 (rIL-2) administered by continuous intravenous (CIV) infusion to patients with metastatic renal cell cancer (RCC). PATIENTS AND METHODS: Thirty patients with RCC were given rIL-2 18 MIU/m2/d CIV. The schedule consisted of two induction cycles and four maintenance cycles with a 3-week rest period between cycles. Each induction cycle consisted of two infusion periods lasting 120 and 108 hours, respectively, separated by a 6-day rest period. Each maintenance cycle consisted of a 120-hour infusion period. RESULTS: Among 29 assessable patients, the objective response rate was 14% (95% confidence interval, 2% to 26%); one patient achieved a complete response, and 3 partial responses. Ten patients (34%) had stable disease (SD). Median survival was 11 months. Toxicity was generally manageable. Hypotension was universal, but required dose reduction in only 2 patients. Increase in serum creatinine levels was observed in 20 patients, and returned to normal in all but 4 patients after discontinuation of treatment. CONCLUSION: Results confirm the efficacy of rIL-2 in patients with RCC and the feasibility of the treatment in a normal oncology ward. However, responses are observed in a minority of patients, and treatment-related toxicity, as well as technical problems, may be troublesome to many patients.     

The cellular interaction of 5-fluorouracil and cisplatin in a human colon carcinoma cell line

The combination of 5-fluorouracil (5-FU) and cisplatin (CDDP) has been shown to have synergistic cytotoxicity in human tumours, but the biochemical mechanism for this interaction remains unclear. Therefore, the aim of this study was to investigate the interaction of 5-FU and CDDP in a human colon carcinoma cell line, NCI H548. A 24 h exposure to 5-FU resulted in a 5-FU IC50 value of 24.2 +/- 4.5 microM, Dm 22.6 microM; exposure to CDDP for 2 h resulted in a IC50 value of 20.8 +/- 8.0 microM, Dm 21.9 microM. When cells were exposed simultaneously to 5-FU for 24 h and CDDP for the initial 2 h, or when cells were treated with CDDP for 2 h followed by various concentrations of 5-FU for 24 h, no greater than additive cytotoxicity was observed. In contrast, when cells were treated with 5-FU for 24 h prior to CDDP for 2 h, a greater than additive interaction was noted (5-FU IC50 1.2 +/- 0.6 microM, Dm 1.3 microM, CI 0.45). Thymidine 10 microM partially reversed the growth inhibitory effects of the 5-FU/ CDDP combination. Using both immunological and biochemical assays, no notable differences in the total amount of TS enzyme or the fraction of bound TS enzyme could be detected in the absence or presence of CDDP. No notable differences could be detected in intracellular reduced folate pools, FdUMP or FUTP pools, or 5-FU incorporation into RNA or DNA with the addition of CDDP to 5-FU. DNA fragmentation studies revealed that the combination of 5-FU followed by CDDP demonstrated a greater degree of single-stranded DNA fragments in parental (P = 0.024) and newly synthesised DNA (P = 0.025) compared with the administration of CDDP prior to 5-FU or either drug alone. The increase in smaller DNA fragment size was reversed with the addition of thymidine (10 microM). These findings suggest that the interaction of 5-FU and CDDP is associated with a greater degree of fragmentation of both nascent and parental DNA.     

A phase II pilot trial of 13-cis retinoic acid and interferon-alpha in patients with advanced pancreatic carcinoma

BACKGROUND: Advanced unresectable pancreatic adenocarcinoma has a dismal prognosis. The authors previously have shown that retinoic acid (RA) and interferon-alpha (IFN-alpha) inhibit growth and induce differentiation in human pancreatic carcinoma cells in vitro and in vivo. The purpose of this trial was to examine the feasibility and tolerability of a combination therapy of 13-cis RA and IFN-alpha in patients with advanced unresectable pancreatic carcinoma. METHODS: Twenty-two patients (median age, 62 years) with histologically confirmed, unresectable pancreatic adenocarcinoma classified as International Union Against Cancer Stage III (5 patients) or IV (17 patients) were included. Patients received 1 mg/kg body weight 13-cis RA orally and 6 million IU IFN-alpha subcutaneously daily. Restaging by ultrasound, computed tomography scan, and chest X-ray was performed every 2 months. RESULTS: No complete remission and 1 partial remission (PR) (4.5%) were observed. Fourteen patients (63.6%) demonstrated stable disease with a median duration of 5.0 months (range, 2.3-17.7+ months). Toxicity mainly was related to IFN-alpha and predominantly was hematologic (no toxicity was World Health Organization [WHO] Grade 4 and 13.6% were WHO Grade 3). Nonhematologic toxicities did not exceed Grade 2 (skin and oral mucosa) and mainly were related to 13-cis RA. The median survival of the patients with Stage III disease was 8.7 months (range, 6.8-23.9+ months) and was 7.4 months for patients with Stage IV disease (range, 0.9-19.2+ months), resulting in a median overall survival of 7.7 months (range, 0.9-23.9+ months). CONCLUSIONS: Combination therapy with 13-cis RA and IFN-alpha is feasible and well tolerated in patients with advanced pancreatic carcinoma. Based on the median survival rates observed in this study this combination should be investigated further in Phase III trials.