Piroxicam selectively inhibits the growth of premalignant and malignant human oral cell lines by limiting their progression through the S phase and reducing the levels of cyclins and AP-1

Studies have shown that nonsteroidal antiinflammatory drugs (NSAIDs) reduce the risk of and mortality from a variety of cancers. Although cyclooxygenase (COX)-dependent and -independent pathways may be involved, the mechanisms responsible for these effects remain unknown. In our study, we found that piroxicam inhibited cell growth in premalignant and malignant, but not normal, human oral epithelial cell lines in a concentration- and time-dependent manner. After 6 days of exposure, the concentration that inhibited growth by 50% was 181 and 211 microM for premalignant and malignant cells, respectively. Piroxicam did not induce apoptosis. The growth inhibitory effect was COX and PGE2 independent. Adding PGE2 or infecting cells with a COX-1 transgene did not abrogate piroxicam-induced growth inhibition. After treatment of the premalignant and malignant cell lines with piroxicam, cells accumulated in the S phase of the cell cycle. Upon removal of piroxicam, cells entered the G2 phase. The S phase block was accompanied by a reduction in the protein levels of cyclin A, cyclin B1, cyclin D1, cdc2, PCNA and the c-jun AP-1 component. Therefore, piroxicam may exert its growth inhibitory effects selectively on the premalignant and malignant human oral epithelial cells lines via signaling pathways regulating the progression of cells through the S phase of the cell cycle.     

c-jun/AP-1 activation does not affect the antiproliferative activity of phenethyl isothiocyanate, a cruciferous vegetable-derived cancer chemopreventive agent

Cruciferous vegetable-derived isothiocyanates (ITCs) display potent cancer chemopreventive activity, but also markedly stimulate oncogenic activator protein 1 (AP-1). AP-1 is well known to promote cell survival and proliferation. We examined the impact of AP-1 activation on antiproliferative activity of ITCs, using bladder cancer cells and phenethyl isothiocyanate (PEITC) as models. AP-1 transactivation induced by PEITC was almost completely suppressed by a dominant-negative c-jun (TAM67). However, suppression of AP-1 transactivation did not affect PEITC-induced apoptosis or cell-cycle arrest. Moreover, we previously showed that in response to ITC treatment c-jun was predominantly stimulated among AP-1 family members largely by c-jun N-terminal kinase (JNK) [Food Chem Toxicol 2005; 43: 1373-1380], but neither JNK inhibition nor forced expression of c-jun altered the antiproliferative activity of PEITC. In addition, cyclin D1, which is considered as an AP-1 target gene and promotes cell proliferation, was markedly elevated in PEITC-treated cells. Unexpectedly, neither TAM67 or JNK inhibition, nor forced c-jun expression had a significant impact on cyclin D1 induction by PEITC, indicating that c-jun/AP-1 does not play an important role in cyclin D1 induction by PEITC. In conclusion, despite the known role of c-jun/AP-1 as a stimulator of cell growth and proliferation, our data show that its activation does not diminish the antiproliferative activity of PEITC and is not responsible for cyclin D1 induction by PEITC.     

Phase II trial of neoadjuvant chemotherapy with docetaxel,nedaplatin, and S1 for advanced esophageal squamous cell carcinoma

Although standard chemotherapy for esophageal cancer patients is fluorouracil and cisplatin, the prognosis is still unsatisfactory. A new therapeutic regimen combining docetaxel, cisplatin, and 5‐fluorouracil was recently developed to improve both local and distant tumor control. We developed a new regimen of docetaxel, nedaplatin, and S1 (DGS) and previously reported the recommended dose in a phase I dose‐escalation study. We then undertook a phase II study of DGS for advanced esophageal squamous cell carcinoma. Patients with clinical stage IB/II/III disease were eligible. Patients received two courses of chemotherapy: docetaxel 35 mg/m² with nedaplatin 40 mg/m² on day 8, 80 mg/m² S1 on days 1–14, and 2 weeks off. After completion of chemotherapy, patients underwent esophagectomy. The primary endpoint was the completion rate of protocol treatment (completion of two courses of preoperative chemotherapy and R0 surgery [no residual tumor]). We enrolled 32 patients. The completion rate of protocol treatment was 96.9%. During chemotherapy, the most common grade 3 or 4 toxicity was neutropenia (25.0%). No treatment‐related deaths were observed, and the incidence of operative morbidity was tolerable. The overall response rate after chemotherapy was 83.3%. This DGS regimen was well tolerated and highly active. This trial is registered with the University Hospital Medical Information Network (UMIN ID: 000014626).     

Phase II study of S-1 in patients with advanced biliary tract cancer

The aim of this study was to investigate the efficacy and safety of an oral fluoropyrimidine derivative, S-1, in patients with advanced biliary tract cancer. Patients with pathologically confirmed advanced biliary tract cancer, a measurable lesion, and no history of radiotherapy or chemotherapy were enrolled. S-1 was administered orally (40 mg m(-2) b.i.d.) for 28 days, followed by a 14-day rest period. A pharmacokinetic study was performed on day 1 in the initial eight patients. In all, 19 consecutive eligible patients were enrolled in the study between July 2000 and January 2002. The site of the primary tumour was the gallbladder (n=16), the extrahepatic bile ducts (n=2), and the ampulla of Vater (n=1). A median of two courses of treatment (range, 1-12) was administered. Four patients achieved a partial response, giving an overall response rate of 21.1%. The median time-to-progression and median overall survival period were 3.7 and 8.3 months, respectively. Although grade 3 anorexia and fatigue occurred in two patients each (10.5%), no grade 4 toxicities were observed. The pharmacokinetic parameters after a single oral administration of S-1 were similar to those of patients with other cancers. S-1 exhibits definite antitumour activity and is well tolerated in patients with advanced biliary tract cancer.     

Phase II trial of oral S-1 combined with gemcitabine in metastatic pancreatic cancer

We conducted a phase II trial of gemcitabine with S-1, oral fluorouracil (5-FU) prodrug tegafur combined with two modulators, 5-chloro-2, 4-dihydroxypyridine and potassium oxonate, to evaluate the activity and toxicity of such a combination in metastatic pancreatic cancer (MPC) patients. Patients who had pathologically proven pancreatic cancer with metastatic lesions were eligible candidates for entry into the study. S-1 was given orally (30 mg m(-2)) b.i.d. for 14 consecutive days and gemcitabine (1000 mg m(-2)) was given on days 8 and 15. The cycle was repeated every 21 days. We enrolled 33 MPC patients. The median number of cycles was eight (range 1-20). Grade 3-4 toxicities were leucopenia (33%), neutropenia (55%), anaemia (9%), thrombocytopenia (15%), anorexia (6%), fever (9%), and interstitial pneumonia (6%). Objective responses were obtained in 16 patients (one complete response and 15 partial responses; response rate, 48%; 95% confidence interval (CI), 33-65). Median survival and 1-year survival rate were 12.5 months (95% CI, 5.9-19.1) and 54% (95% CI, 36-72), respectively. Combination chemotherapy with GEM and S-1 was well tolerated and yielded a significantly high response rate.     

Phase I/II study of S-1 combined with weekly docetaxel in patients with metastatic gastric carcinoma

We designed a phase I/II trial of S-1 combined with weekly docetaxel to determine the maximum tolerated dose (MTD) and recommended dose (RD) and to evaluate the efficacy and toxicity in metastatic gastric carcinoma (MGC). Patients with measurable disease received S-1 orally b.i.d. on days 1-14 and docetaxel intravenously on days 1 and 8 every 3 weeks. In phase I (n=30), each cohort received escalating doses of S-1 (30-45 mg m(-2) b.i.d.) and docetaxel (25-40 mg m(-2)); MTD was 45 mg m(-2) b.i.d. S-1/35 mg m(-2) docetaxel and RD was 40 mg m(-2) b.i.d. S-1/35 mg m(-2) docetaxel. Dose-limiting toxicities included grade 3 elevated liver enzymes, gastric perforation, grade 3 diarrhoea/fatigue, febrile neutropenia with grade 3 anorexia/fatigue, and neutropenic infection with grade 3 stomatitis/anorexia. In phase II (n=52), the overall response rate was 66.7% (95% confidence interval (CI): 53.8-79.6%) and the median time to progression and overall survival were 6.5 months (95% CI: 4.9-8.1) and 13.7 months (95% CI: 9.9-17.5), respectively. The most common grade 3/4 toxicity was neutropenia (29.4%), and febrile neutropenia/neutropenic infection occurred in 19.6% of patients. Non-haematological toxicities were generally mild. There was one treatment-related death due to pneumonitis. S-1 combined with weekly docetaxel is active in MGC with moderate toxicities.     

Phase I/II study of docetaxel and S-1 in patients with advanced gastric cancer

The aims of this phase I/II study of docetaxel and S-1 were to determine the dose-limiting toxicity (DLT), maximum-tolerated dose (MTD), and recommended dose (RD) in the phase I part and to explore the tumour response, survival and safety in the phase II part. Patients with histologically- or cytologically confirmed unresectable or recurrent gastric cancer were eligible. Treatment consisted of intravenous docetaxel on day 1 (starting dose 50 mg m(-2)) and oral S-1 at a fixed dose of 40 mg m(-2) twice daily on days 1-14, every 4 weeks up to six cycles. Nine patients took part in the phase I portion of the study. The MTD of docetaxel was determined to be 50 mg m(-2), with the DLTs of grade 3 infection associated with grade 3 neutropenia and grade 4 neutropenia during S-1 administration. The RD of docetaxel was 40 mg m(-2) in combination with S-1 40 mg m(-2) b.i.d. The efficacy and safety of this regimen was therefore assessed in 46 patients with at least one measurable lesion. The overall response rate and estimated median overall survival were 46% (95% CI, 31-61%) and 14.0 months (8.3-17.3 months), respectively. The most common grade 3/4 toxicity was neutropenia (67% of patients), which was predictable and manageable. This regimen showed promising activity with moderate toxicities in advanced gastric cancer.     

Phase II study of S-1, a novel oral fluorouracil, in advanced non-small-cell lung cancer

The purpose of this study was to evaluate the efficacy and safety of a novel oral anticancer fluoropyrimidine derivative, S-1, in patients receiving initial chemotherapy for unresectable, advanced non-small-cell lung cancer (NSCLC). Between June 1996 and July 1998, 62 patients with NSCLC who had not received previous chemotherapy for advanced disease were enrolled in this study. 59 patients (22 stage IIIB and 37 stage IV) were eligible for the evaluation of efficacy and safety. S-1 was administered orally, twice daily, after meals. 3 dosages of S-1 were prescribed according to body surface area (BSA) so that they would be approximately equivalent to 80 mg m(-2)day(-1): BSA < 1.25 m(2), 40 mg b.i.d.; BSA> or =1.25 but <1.5 m(2); 50 mg b.i.d., and BSA> or =1.5 m(2): 60 mg b.i.d. One cycle consisted of consecutive administration of S-1 for 28 days followed by a 2-week rest period, and cycles were repeated up to 4 times. The partial response (PR) rate of the eligible patients was 22.0% (13/59); (95% confidence interval: 12.3-34.7%). A PR was observed in 22.7% (5/22) of the stage IIIB patients and 21.6% (8/37) of the stage IV patients. The median response duration was 3.4 months (1.1-13.7 months or longer). Grade 4 neutropenia was observed in one of the 59 patients (1.7%). The grade 3 or 4 toxicities consisted of decreased haemoglobin level in 1.7% of patients (1/59), neutropenia in 6.8% (4/59), thrombocytopenia in 1.7% (1/59), anorexia in 10.2% (6/59), diarrhoea in 8.5% (5/59), stomatitis in 1.7% (1/59), and malaise in 6.8% (4/59), and their incidences were relatively low. There were no irreversible, severe or unexpected toxicities. The median survival time (MST) of all patients was 10.2 months (95% confidence interval: 7.7-14.5 months), and the one-year survival rate was 41.1%. The MST of the stage IIIB patients was 7.9 months, and that of the stage IV patients was 11.1 months. The one-year survival rates of the stage IIIB and IV patients were 30.7% and 47.4%, respectively. S-1 was considered to be an active single agent against NSCLC. Further study of S-1 with other active agents is warranted.     

Phase II study of oral S-1 plus irinotecan in patients with advanced colorectal cancer: Hokkaido Gastrointestinal Cancer Study Group HGCSG0302

We have previously reported on phase I/II studies of irinotecan plus S-1 therapy for advanced gastric cancer. Based on the safety and efficacy data that were obtained, this phase II study was planned to assess the efficacy of irinotecan plus S-1 for patients with advanced colorectral cancer. A total of 40 patients are enrolled at 13 medical institutions. The objective of this study was to establish a useful chemotherapy regimen for an out-patient setting.     

Phase I/II trial of a biweekly combination of S-1 plus docetaxel in patients with previously treated non-small cell lung cancer (KRSG-0601)

Background:

Combination of S-1, an oral fluorouracil derivative, plus docetaxel against non-small cell lung cancer (NSCLC) showed promising efficacy but clinically problematic emesis. A phase I/II study utilising a new schedule for this combination was conducted.

Methods:

A biweekly regimen of docetaxel on day 1 with oral S-1 on days 1–7 was administered to previously treated NSCLC patients. Doses of docetaxel/S-1 were escalated to 30/80, 35/80, and 40/80 mg m⁻², respectively, and its efficacy was investigated at the recommended dose below maximum tolerated dose (MTD).

Results:

In phase I study employing 13 patients, dose-limiting toxicities were febrile neutropenia and treatment delay, with the respective MTDs for docetaxel 40 mg m⁻²/S-1 80 mg m⁻². In the phase II study, 34 patients were treated with docetaxel 35 mg m⁻²/S-1 80 mg m⁻² for a median cycle of 6. The response and disease control rates were 34.3% (95% confidence interval (CI), 18.6–50.0%) and 62.9% (95% CI, 46.8–72.9%), respectively. Median progression-free survival was 150.5 days. Haematologic grade 4 toxicities were observed in neutropenia (11.8%) and thrombocytopenia (2.9%). Regarding non-haematologic toxicities, including emesis, there were no grade 3/4 side effects.

Conclusion:

Combination of 1-week administration of S-1 with biweekly docetaxel is safe and active for NSCLC.     

Early phase II study of S-1, a new oral fluoropyrimidine, for advanced non-small-cell lung cancer

Background. The efficacy and safety of S-1, a new oral fluoropyrimidine, were evaluated in patients with non-small-cell lung cancer (NSCLC). The objective of this study was to determine whether the drug should be investigated in a late phase II study. Methods. Each treatment course consisted of an oral dose of S-1, 50 mg/body or 75 mg/body, twice a day for 28 days, followed by a 2-week washout period. Results. Fifty-six eligible patients were enrolled. Five of the 40 previously untreated patients (12.5%; 90% confidence interval, 6.2%–23.5%) showed a partial response (PR), and no tumor response was observed in the 16 previously treated patients. The median survival duration in all eligible patients was 8.4 months, with a 1-year survival rate of 27.3%. The incidences of grade 3 or more severe adverse effects were: anemia, 5.4%; leukopenia, 5.4%; neutropenia, 5.4%; thrombocytopenia, 1.8%; anorexia, 3.6%; diarrhea, 3.6%; and general fatigue, 5.4%. These effects disappeared after cessation of the drug or appropriate treatment. One patient died as a result of aggravated interstitial pneumonitis, but the relationship of this event to S-1 was not clear. Conclusion. S-1 showed modest activity with mild toxicity in the treatment of non-small-cell lung cancer. Based on this result, we will progress to the next stage of a late phase II study for advanced NSCLC, and a phase II study of S-1 and cisplatin for advanced gastric cancer. Final results will be reported as they are obtained. Received: February 13, 2001 / Accepted: August 28, 2001