Taxotere???5???-deoxy-5-fluorouridine combination on hormone-refractory human prostate cancer cells

Single-agent docetaxel (Taxotere) treatment has recently demonstrated promising clinical activity in patients with advanced hormone-refractory prostate cancer. Taxanes were recently found to upregulate the tumoral activity of thymidine phosphorylase (TP), a key cellular enzyme [transformation of 5'-deoxy-5-fluorouridine (5'-DFUR) into 5-fluorouracil] in the activation cascade of capecitabine (Xeloda). We tested (cytotoxic effects and molecular mechanisms) the Taxotere-5'-DFUR combination on hormone-refractory prostate cancer cell lines (DU145 and PC3). Cells were exposed to Taxotere and/or 5'-DFUR in three different sequences: Taxotere was given alone for 48 h, then 5'-DFUR was added for 48 h; Taxotere and 5'-DFUR together during 96 h or 5'-DFUR was given alone for 48 h then Taxotere was added for 48 h. The drug sequence Taxotere applied first followed by 5'-DFUR led to synergistic cytotoxic effects on both cell lines; the other sequences resulted in simple additivity. Taxotere did not modify TP activity while it decreased thymidylate synthase activity. There was an increase in CD95 cellular membrane levels following exposure to Taxotere-5'-DFUR, which is in agreement with the supra-additive cytotoxic combination. This observation may serve as a preclinical rationale for a next step testing the Taxotere-capecitabine combination at the clinical level in prostate cancer patients.

Doxycycline may reduce the incidence of aneurysms in haemodialysis vascular accesses

BACKGROUND

Doxycycline can prevent aortic aneurysms through the inhibition of enzymes that degrade vessel walls. We investigated whether haemodialysis patients who had received one or more courses of doxycycline were at less risk for aneurysms in their vascular accesses than those who had received other antibiotics.

METHODS

Three hundred and eight patients undergoing chronic maintenance hemodialysis were evaluated for aneurysm formation after exposure to doxycycline or another antibiotic. Conditional forward logistical analysis using Cox proportional hazards test (SPSS) was performed to determine the potential significance of differences of aneurysm formation between the two groups.

RESULTS

Patients who had received doxycycline appeared to be at lower risk than the control group, but the effect was most obvious in those patients with synthetic grafts.

CONCLUSIONS

Doxycycline may have the ability to reduce aneurysm formation in haemodialysis vascular accesses and a large prospective study is warranted.

A randomized controlled study of immunochemotherapy with OK-432 after curative surgery for gastric cancer

The effect of adjuvant immunochemotherapy including OK-432 (Picibanil) on survival was assessed in patients who underwent curative resection of gastric cancer. Patients enrolled in this randomized controlled study were randomly assigned to group A or group B. Group A patients received 800 mg/d 5'-DFUR (Furtulon) for 2 years from 2 weeks after the operation. Group B patients received OK-432 plus 5'-DFUR by the same regimen as in group A. This study enrolled 288 patients, and 1 patient with malignant lymphoma was excluded. Among the remaining 287 patients, 143 and 144 were allocated to group A and group B, respectively, and their data were included in statistical analysis. The 5-year survival rates for groups A and B were 62.9% and 63.8%, respectively, showing no significant difference (P = 0.7996).

The benefit of post-operative adjuvant chemotherapy using oral fluoropyrimidines in rectal cancer

Recent meta-analysis has shown that oral fluoropyrimidenes is effective as post-operative adjuvant therapy in stage II or III colorectal cancer. However, because the efficacy of oral fluoropyrimidines was expected to be mild, it is important to know patients who respond to this mild chemotherapy for reasonable adjuvant therapy for rectal cancer. To clarify the benefit and problems of the post-operative adjuvant chemotherapy using oral fluoropyrimidines, the clinicopathological data of 169 rectal cancer patients treated with or without the post-operative chemotherapy were analyzed retrospectively. Patients in chemotherapy group (n = 100) underwent curative resection with lymphadenectomy were followed by administration of oral fluoropyrimidine. Other 69 patients underwent surgery alone. The disease-free survival rates were compared between the two groups. The disease-free survival rate in the chemotherapy group was significantly higher than that in the surgery alone. However, no significant difference in disease-free survival rate was found for those with tumor which was associated with metastasis of mesenteric lymph node or node belonging to the internal iliac artery, and tumor with lymphatic invasion or venous invasion. Post-operative adjuvant chemotherapy using oral fluoropyrimidines such as UFT and 5'-DFUR might not reduce the risk of recurrence in rectal cancer with metastasis of mesenteric lymph node or node belonging to the internal iliac artery, and with lymphatic permeation and venous invasion.

[Significance of tissue thymidine phosphorylase and dihydropyrimidine dehydrogenase activities in ovarian cancer]

Thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) are important enzymes in the pyrimidine salvage pathway. In the meantime, TP and DPD are a converting enzyme of 5'-DFUR to 5-FU and the major catabolic enzyme of 5-FU, respectively. Because little is known about their protein expressions in ovarian cancers, we investigated TP and DPD protein expressions quantitatively in 24 ovarian cancers and their normal counterparts by ELISA. Higher TP expression was observed in ovarian cancers than in normal ovaries. The higher expression was also correlated with the histological grade and clinical stage. No relation was observed between the expression of DPD and the clinical and pathological parameters. The higher TP/DPD ratio, which appears to be a predictor of 5-fluorouracil sensitivity, was observed in ovarian cancers than in normal counterparts. In univariate analysis, a higher TP/DPD ratio was found to be a predictor of progression-free survival in ovarian cancer patients. This would suggest that capecitabine and 5'-DFUR are potential candidates for ovarian cancer chemotherapy.

A novel combination antimetabolite, TAS-102, exhibits antitumor activity in FU-resistant human cancer cells through a mechanism involving FTD incorporation in DNA

TAS-102 is a new antimetabolite agent composed of a alpha, alpha, alpha-trifluorothymidine (FTD; 1 M) and thymidine phosphorylase inhibitor (TPI; 0.5 M). Here, we investigated the antitumor effect and mechanism of TAS-102 against 5-FU, or FdUrd, resistant human cancer cell lines. The respective tumor growth inhibition rate of orally administered FTD against 5-FU-resistant NUGC-3 was about 70% at a dose level of 200 mg/kg/day; this value was comparable to that against the parental NUGC-3. On the other hand, the tumor inhibition rates of 5-FU, FdUrd, and TS-1 against 5-FU-resistant NUGC-3 were lower than those against parental NUGC-3. Similar observations were made in an FdUrd-resistant human colorectal cancer cell line (DLD-1). TAS-102 was also effective in 5-FU-less sensitive human pancreatic cancer cell lines (PAN-12 and BxPC-3) and human esophagus cancer (T.T.) when compared with 5-FU or UFT. Our hypothesis was that a relatively short and high dosage of TAS-102 results in an additional mechanism of FTD incorporation into DNA other than thymidylate synthase (TS) inhibition. We then examined the effects of FTD on DNA at the cellular level. After treatment with FTD or FdUrd, the DNA fragmentation pattern was examined using filter elution and in situ nick translation. Treatment with FTD for 2 h resulted in marked DNA fragmentation. When the tumor cells were treated with FTD for 72 h or with FdUrd for 2 or 72 h, only a small amount of DNA fragmentation was observed, and the appearance of the tumor cells did not differ markedly from that of untreated cells. Moreover, the DNA fragmentation rate in the TAS-102 treatment group was significantly higher than that in the control group in vivo. These results suggest that when tumor cells are exposed to high concentrations of FTD for short periods of time, FTD manifests its antitumor activity primarily through the induction of DNA fragmentation after FTD incorporation into the DNA. We conclude that TAS-102 is expected to manifest antitumor effects against 5-FU-resistant tumors that are similar to those exerted in 5-FU-sensitive tumors.

The ratio of thymidine phosphorylase to dihydropyrimidine dehydrogenase in tumour tissues of patients with metastatic gastric cancer is predictive of the clinical response to 5'-deoxy-5-fluorouridine

The aim of this work was to determine whether intratumour contents of thymidine phosphorylase (TP), which converts 5'-deoxy-5-fluorouridine (5'-DFUR) to 5-fluorouracil, and dihydropyrimidine dehydrogenase (DPD), which degrades 5-fluorouracil to inactive molecules, could be useful in predicting the response of patients with metastatic gastric cancer to chemotherapy using 5'-DFUR. Endoscopic biopsy specimens for the measurement of TP and DPD were obtained from the primary lesions before the start of combination chemotherapy, in which 5'-DFUR, cisplatin and mitomycin C were administered. TP and DPD were measured by enzyme-linked immunosorbent assays after the objective responses to chemotherapy had been confirmed. Twenty five patients were enrolled in this study and data for 22 patients in whom responses were confirmed were analysed. The median levels (ranges) of TP and DPD were 80 (4.9-360) and 44 (15-82) U/mg protein, respectively. The median value (range) of TP to DPD ratios was 1.9 (0.25-5.1). Eight patients with a complete or partial response to chemotherapy had significantly higher TP to DPD ratios than did the remaining patients with stable or progressive disease (P = 0.014). When a cut-off level of TP to DPD ratio was defined as the median value, the high-ratio group (n = 11) showed a significantly higher response rate (64% vs. 9.1%, P = 0.024) than the low-ratio group (n = 11). Overall survival of the high-ratio group was significantly longer than that of the low-ratio group (the median survival time; 300 days vs. 183 days, P = 0.047). The efficacy of 5'-DFUR could be optimised by preselecting patients with high TP/ DPD ratios in their tumour tissues, and this would be applicable to the treatment with capecitabine.

[The effect of pre-operative chemotherapy on calpain in cells of gastrointestinal malignant tumors]

OBJECTIVE

Primary to search the rule of pre-operative chemotherapy and suitable duration for it by investigating the changes of calpain content and activity after 5'-deoxy-5-fluorouridine (5'-DFUR) per oral administered pre-operatively in different time. Further to investigate the mechanism of chemotherapy.

METHODS

Seventy-three patients with gastrointestinal malignant tumors were divided into 4 groups by the time of 5'-DFUR (600 approximately 1200 mg/d) by oral administration before operation, group A, 3 days, 27 cases; group B, 1 week, 22 cases; group C, 2 weeks, 15 cases; group D, 2 months, 9 cases. And group E, control group, had 24 patients with gastrointestinal malignant tumors at the same term. The patients above all had not received the other chemotherapy and radiotherapy. Western blot and immunoelectron microscopy were employed to detect the expressing levels and activities of calpain in tumor tissues of different groups.

RESULTS

Electronic microscopic examination showed gold granula mainly on the membranes of mitochondria of tumor cells to groups after chemotherapy. And the tumor cells of group A were mildly damaged. Besides that, serious injury for tumor cells of group B could be seen, and the phenomena were common in group C. But the damages to tumor cells of group D were mainly about mildness. The results of immunoelectron microscopy revealed that the contents of calpain increased following the time of chemotherapy prolonging, and peaked in group C. Still more, there was no significant difference for the results between group C and group D. The changes of calpain activities observed by western blot had the same tendency as the results from immunoelectron microscopy (r = 0.86, P < 0.0001).

CONCLUSIONS

5'-DFUR via oral administered pre-operation could have anti-cancer effect through calpain. And the effect might be strongest in 2 weeks also after chemotherapy.

[A case of liver metastasis of colon cancer responding remarkably to 5'-DFUR]

A 65-year-old man was referred to our hospital because of diarrhea due to sigmoid colon cancer. Abdominal CT scan revealed a hepatic tumor (S8) about 2 cm in diameter. We performed a sigmoidectomy and planned to resect the liver metastasis 1 or 2 months later. Pathological findings showed moderately differentiated adenocarcinoma, s, n1. Two weeks after the surgery, 5'-DFUR was administered at 600 mg/day. An abdominal CT scan 2 months later demonstrated regression of the liver metastasis and another scan 4 months later showed the tumor had disappeared. 5'-DFUR was administered for about 2 years. Five years after the surgery, the patient is alive without recurrence and CEA level is in normal range.

A phase II trial of FUdR in patients with advanced pancreatic cancer

PURPOSE

This phase II study was conducted to assess the efficacy of fluorodeoxyuridine (FUdR) in patients with metastatic, advanced pancreatic cancer who had no previous chemotherapy.

PATIENTS AND METHODS

Twenty patients were enrolled in this single institution trial. The primary endpoint of this study was the assessment of overall survivorship. The secondary endpoints were to estimate the time to tumor progression and the assessment of toxicity in this cohort of patients. Treatment consisted of FUdR 150 mg/kg dissolved in 500 cc normal saline intravenous infusion over 24 h. Eight weeks of treatment constituted one course of chemotherapy. Tumor measurements were conducted at 8-weekly intervals.

RESULTS

Four patients achieved partial response and 16 patients had stable disease. Median survival of patients treated with FUdR was 11.6 months with a range of 3-16 months. Median progression-free survival was 6 months. Overall, chemotherapy was well tolerated with low incidence of grade 3 or 4 toxicity.

CONCLUSIONS

Systemic chemotherapy with high dose FUdR administered on a weekly schedule has led to encouraging survival outcomes and improved quality of life as compared to previous phase II single agent chemotherapeutic trials.

Prediction of 5'-deoxy-5-fluorouridine sensitivity in colorectal cancer cases by thymidine phosphorylase activity and preliminary identification of susceptibility related genes

We confirmed that the enzyme activity of thymidine phosphorylase (TP) can substitute for 5'-deoxy-5-fluorouridine (5'-dFUR) sensitivity in clinical colorectal cancer (CRC) tissues. Moreover, the idenfication of susceptible genes other than TP will be desired for prediction or treatment of 5'-dFUR. We initially established conditions for the MTT assay system in vivo to compare the growth inhibition rate and TP activity in 18 cases of CRC. TP activity levels were concordant with 5'-dFUR sensitivity in the CRCs (p<0.05). In 18 CRC cases, 4 cases of high sensitivity and 3 cases of low sensitivity to 5'-dFUR were compared to analyze expression profiles of 9437 genes on cDNA microarray chips. As a result, a cluster of genes related to the sensitivity were identified and another cluster of genes related to the insensitivity of 5'-DFUR were also listed. We determined that TP expression can precisely predict 5'-dFUR sensitivity in CRCs and found susceptibility related genes.

Floxuridine-containing regimens in the treatment of gestational trophoblastic tumor

OBJECTIVE

To analyze the efficacy of floxuridine (FUDR)-containing regimens in the treatment of gestational trophoblastic tumor (GTT).

STUDY DESIGN

Seventy-four patients with GTT, 47 with invasive mole and 27 with choriocarcinoma were treated with FUDR-containing regimens. Clinical staging of the disease was: 33 cases of stage I, 3 cases of stage II, 31 cases of stage IIIa, 6 cases of stage IIIb and 1 case of stage IV.

RESULTS

The complete response rate of FUDR-containing regimens in the treatment of GTT was 91.9% (68 of 74 cases). Six patients, of whom 3 showed signs of drug resistance and 3 showed myelosuppression, had their regimens changed to non-FUDR-containing regimens, and all achieved a complete response. All 7 patients with advanced disease (>IIIb) achieved a complete response. The major adverse event with FUDR-containing regimens was myelosuppression and gastrointestinal toxicity: third- and fourth-degree neutropenia in 26% and thrombocytopenia in 6.2%, third-degree vomiting in 57.1% and third-degree diarrhea in 4.3%.

CONCLUSION

FUDR-containing regimens are efficient for the treatment of GTT even for patients with advanced or drug-resistant disease.

Therapeutic effects of novel anti-tumor reagent, apoptosis inducing nucleosides from CD57+HLA-DRbright natural suppressor cell line on human gastric carcinoma-bearing SCID mice

To further provide scientific evidence before clinical application, the anti-tumor effects of apoptosis inducing nucleosides (AINs) released from CD57+HLA-DRbright natural suppressor (CD57.DR-NS) cell line on human gastric carcinoma (GCIY)-bearing severe combined immunodeficiency (SCID) mice were examined by monitoring tumor cell growth and change of body weight of mice. The results obtained evidenced that AINs strongly induced apoptosis in the tumor tissues in SCID mice with decrease of tumor size and without loss of body weight. We found that peak 5 and peak 6 (P5 and P6) components among six components (AINs) isolated from CD57.DR-NS cell cultures by high performance liquid chromatography (HPLC) are the most effective. The anti-tumor effective dosage of P5, P6 and their mixture, P5+P6, were obtained in dose-dependent manner. Thus, the most effective method of administration of AINs for tumor regression without exhaustion was established in the present study. Corresponding to the previous study that AINs could generate apoptosis in malignant cells while lacking the toxicity in normal cells, the results obtained in the present preclinical experiments suggested anti-tumor efficacy of AINs with possible refrainment from side-effects in clinical trials.

Gemcitabine in Patients With Solid Tumors and Renal Impairment

The purpose of this phase I study was to determine the pharmacokinetics and toxicity of gemcitabine in patients with advanced, recurrent, and/or metastatic cancer and renal impairment. Patients were entered in 4 groups estimated by EDTA-Cr plasma clearance (CLp, mL/min): > or =80; > or =60 and <80; > or =30 and <60; and > or =30 and <80 plus renal insufficiency induced by previous chemotherapy, respectively. Gemcitabine 500 to 1000 mg/m was administered intravenously on days 1, 8, and 15 every 4 weeks. Plasma concentration data were pooled and analyzed using a population pharmacokinetic program (NONMEM). Eighteen white patients (14 females, 4 males) entered the study with a median age of 55 years. Linear regression analyses revealed no significant relationship between gemcitabine CLp and indices of renal impairment (EDTA-Cr CL; p = 0.797 or beta2-microglobulin; p = 0.153). Hematologic and nonhematologic toxicities were mild. Thus, there seems to be no significant impact of mild to moderate renal insufficiency on gemcitabine pharmacokinetics in patients with advanced cancer.

Highly efficient DNA incorporation of intratumourally injected [125I]iododeoxyuridine under thymidine synthesis blocking in human glioblastoma xenografts

Intratumoural (i.t.) injection of radio-iododeoxyuridine (IdUrd), a thymidine (dThd) analogue, is envisaged for targeted Auger electron- or beta-radiation therapy of glioblastoma. Here, biodistribution of [(125)I]IdUrd was evaluated 5 hr after i.t. injection in subcutaneous human glioblastoma xenografts LN229 after different intravenous (i.v.) pretreatments with fluorodeoxyuridine (FdUrd). FdUrd is known to block de novo dThd synthesis, thus favouring DNA incorporation of radio-IdUrd. Results showed that pretreatment with 2 mg/kg FdUrd i.v. in 2 fractions 0.5 hr and 1 hr before injection of radio-IdUrd resulted in a mean tumour uptake of 19.8% of injected dose (% ID), representing 65.3% ID/g for tumours of approx. 0.35 g. Tumour uptake of radio-IdUrd in non-pretreated mice was only 4.1% ID. Very low uptake was observed in normal nondividing and dividing tissues with a maximum concentration of 2.9% ID/g measured in spleen. Pretreatment with a higher dose of FdUrd of 10 mg/kg prolonged the increased tumour uptake of radio-IdUrd up to 5 hr. A competition experiment was performed in FdUrd pretreated mice using i.t. co-injection of excess dThd that resulted in very low tumour retention of [(125)I]IdUrd. DNA isolation experiments showed that in the mean >95% of tumour (125)I activity was incorporated in DNA. In conclusion, these results show that close to 20% ID of radio-IdUrd injected i.t. was incorporated in tumour DNA after i.v. pretreatment with clinically relevant doses of FdUrd and that this approach may be further exploited for diffusion and therapy studies with Auger electron- and/or beta-radiation-emitting radio-IdUrd.

The potential for oral combination chemotherapy of 5'-deoxy-5-fluorouridine, a 5-FU prodrug, and cyclophosphamide for metastatic breast cancer

Preclinical studies have demonstrated the synergistic anti-tumour activity of combination therapy with the oral cytostatics, 5′-deoxy-5-fluorouridine (5′-DFUR) and cyclophosphamide (CPA), in human breast cancer xenograft models. This study was performed to evaluate the efficacy and safety of this oral combination chemotherapy in the treatment of metastatic breast cancer. In all, 101 patients with metastatic breast cancer were enrolled in the study, and the data for 94 eligible patients of these were evaluated. The patients received twice daily oral combinations of 5′-DFUR (1200 mg/body/day) and CPA (100 mg/body/day) for 2 weeks, followed by a 1-week rest period. After a median of 19 treatment cycles (range 1–66 cycles), 16 patients (17.0%) had a complete response, and 40 patients (42.6%) had partial responses. The response rate was 59.6% (95% CI, 49.0–69.6%). The median time to progression and overall survival times were 11.7 and 40.3 months, respectively. The toxicity was mild and tolerable, and the related grade 3/4 clinical adverse effects consisted of haematological toxicity in 21 patients (22%) and nonhaematological toxicity in five patients (5%). These results suggest that the oral combination chemotherapy of 5′-DFUR and CPA has low toxicity and is a novel, very convenient and effective treatment for metastatic breast cancer.

Positive response to oral chemoendocrine combination therapy using 5"-deoxy-5-fluorouridine for locally advanced breast cancer with carcinomatous pleurisy: report of a case

A 60-year-old postmenopausal woman presented with an ulcerating and bleeding tumor in her right breast. On physical examination, the tumor was found mainly in the D area of the right breast, and was associated with ulceration and thoracic rigidity. Chest X-ray showed a pleural effusion in her right chest and a computed tomography scan after thoracentesis showed multiple bilateral pleural nodules. Thus, a diagnosis of unresectable advanced breast cancer (T4cN2M1b, PLE) was made. She was given oral 5"-deoxy-5-fluorouridine (5"-DFUR) with medroxyprogesterone acetate, followed by tamoxifen, without any severe adverse reactions, and was subsequently followed up as an outpatient. Her tumor gradually decreased in size, the thoracic rigidity disappeared, and the pleural dissemination and effusion resolved. Thereafter, a radical mastectomy was performed and histologically, the tumor was Grade 1a. She had no signs of recurrence or metastasis 14 months postoperatively. Therefore, oral chemoendocrine combination therapy with 5"-DFUR resulted in a favorable quality of life, there were no severe adverse reactions, and the patient was able to be managed as an outpatient.

[A case of advanced breast cancer with multiple lung, bone and lymph node metastases successfully treated with 5'-DFUR alone]

A 78-year-old female patient with locally advanced breast cancer, bleeding from a deep ulcer, and with multiple bone, lung and distant lymph node metastases was successfully treated with 5'-DFUR alone. She was at first treated with docetaxel + 5'-deoxy-5-fluorouridine (5'-DFUR) + tamoxifen, but they were discontinued because of deep venous thrombosis. She underwent simple mastectomy due to periodically recurring bleeding and infection. After administration of 5'-DFUR alone, a decrease of abnormal accumulation on a bone scintigram was obtained in 10 months, the lung metastases were diagnosed as being in complete remission (CR) at 11 months and the lymph node metastases were diagnosed as being in CR at 14 months. These states have continued to the present. The administration of 5'-DFUR alone is suitable for tumor dormancy in some cases.

ZD1839 (Iressa) modifies the activity of key enzymes linked to fluoropyrimidine activity: rational basis for a new combination therapy with capecitabine

PURPOSE

The efficacy of new oral fluoropyrimidines, including capecitabine, is improved in cells expressing high levels of thymidine phosphorylase (TP) and low levels of thymidylate synthase (TS) and dihydropyrimidine dehydrogenase. We used a human head and neck cancer cell line (CAL33) to examine the influence of cell cycle modifications on TS, TP, and dihydropyrimidine dehydrogenase activity.

EXPERIMENTAL DESIGN

Cells were exposed to the epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 (Iressa(2)) and 5'-deoxy-5-fluorouridine (5'-DFUR), alone and in combination, for up to 96 h, and modifications in cell cycle, enzyme activity, and gene expression were examined.

RESULTS

ZD1839 (24- to 72-h exposure) markedly reduced proliferation and caused a rapid increase in G(0)-G(1) and a decrease in S phase; a 40-fold decrease in TS activity at 24 h and a 2.5-fold increase in TP activity at 48 h were observed. A significant link between TP activity and expression was observed (r(2) = 0.98; P = 0.0068). Additional investigations pointed out an increased cellular production of 5-fluorouracil anabolites from 5'-DFUR when cells were preincubated with ZD1839. Dose-effect curves of ZD1839 and 5'-DFUR, alone and in combination, were examined. Combination indices for ZD1839 + 5'-DFUR were 0.58 +/- 0.1 and 0.63 +/- 0.1 for 50% survival and 25% survival, respectively. Additional investigations pointed out an increased cellular production of 5-fluorouracil anabolites from 5'-DFUR when cells were preincubated with ZD1839.

CONCLUSIONS

These data demonstrate a strong synergistic interaction between ZD1839 and 5'-DFUR when ZD1839 is applied before or concurrently with 5'-DFUR. Such a drug combination would have two advantages: (a) the theoretical advantage of tumor selectivity of epidermal growth factor receptor-targeted therapy; and (b) the practical advantage of a combination therapy that could be administered p.o.

[A case of multiple liver metastases of colon cancer with PyNPase-positive successfully treated with 5'-DFUR]

A 75-year-old man was diagnosed with transverse colon cancer. We therefore performed a transverse colectomy. Diagnosis of multiple liver metastases was made by intraoperative palpation, core needle biopsy and postoperative abdominal CT scan. 5'-deoxy-5-fluorouridine (5'-DFUR) 800 mg/day was administered orally after the surgery. After 2 months of administration, an abdominal CT scan showed the metastatic lesions of liver were reduced. After 8 months, an abdominal CT scan showed no evidence of liver metastases. Pyrimidine nucleoside phosphorylase (PyNPase), an enzyme that converts 5'-DFUR to 5-FU, has an important role in the expression of the anti-tumor activity of 5'-DFUR. Primary specimens of this case were regarded as PyNPase-positive. We think that administration of 5'-DFUR may be a useful treatment for advanced colon cancer that is PyNPase-positive.

Thymidine phosphorylase expression correlates with malignant potential and anti-tumor effect of doxifluridine on gastric cancer: multivariate analysis for adjuvant chemotherapy doxifluridine vs. 5-fluorouracil

Doxifluridine (5'-DFUR) is an anticancer drug converted to 5-fluorouracil (5-FU) by thymidine phosphorylase (TP). TP is an angiogenetic and platelet-derived endothelial cell growth factor. We evaluated the relation between TP expression and chemotherapeutic efficacy and prognosis for gastric cancer. Advanced gastric cancer patients given oral adjuvant chemotherapeutics either 5'-DFUR; 163 patients or 5-FU; 162 patients were examined. TP expression was assessed with immunohistochemical staining. Multivariate analysis for influencing survival was done, employing variables such as gender, age, procedure, tumor size, location, Borrmann type, histologic factors [type, depth of invasion, lymph node metastasis (n), lymphatic invasion (ly), and venous invasion (v)], drug administered, and TP expression. In the patients with serosal invasion, 5'-DFUR in TP positive was an independent prognostic factor (risk ratio, 4.450; 95% confidence limit, 2.099-9.436), indicating significantly improved prognosis over the 5-FU group. In TP negative, n and ly were independent prognostic factors, but the survival curves of the two chemotherapeutic groups were not significantly different. TP expression was not prognostic factor in 5'-DFUR group, while, in 5-FU group, TP expression was an independent prognostic factor (2.834, 1.467-5.476). In conclusion, it was suggested that TP positive gastric cancer with serosal invasion increased malignant potential of the tumor and 5'-DFUR efficacy.

[PyNPase and DPD expression potentially predict response to 5'-DFUR treatment for node-positive breast cancer patients]

Pyrimidine nucleoside phosphorylase (PyNPase) and dihydropyrimidine dehydrogenase (DPD) activity may be related of the antitumor effect of 5'-deoxy-5-fluorouridine (5'-DFUR). To select patients for adjuvant setting of 5'-DFUR, we assessed PyNPase and DPD activity in 41 primary tumors (PTs) and 227 lymph nodes (LNs) of breast cancer patients. Fifty-one patients were involved in this investigation (mean age 54 +/- 12 years). LN metastasis was positive in 23 cases (node-positive group). Metastatic cancer cells were positive in 65 lymph nodes (In + group). PyNPase and DPD activity were measured by ELISA. PyNPase activity in PTs of the node-positive group was significantly higher than in the node-negative group. PyNPase activity in LNs of In + group was also significantly higher than in the negative metastatic cancer cell group. However, no significant differences were noted between these groups in DPD activity. PyNPase/DPD ratio in LNs of the In + group was marginally higher than in the negative metastatic cancer cell group. These data suggest that 5'-DFUR is preferably sensitive in breast cancer patients with lymph node metastasis.