Hiroo Ishida

Phase II study of irinotecan and carboplatin in patients with the refractory or relapsed small cell lung cancer

We examined the safety and efficacy of the combination of irinotecan plus carboplatin in patients with refractory or relapsed small cell lung cancer (SCLC). Patients with previously treated SCLC were eligible. Patients were treated every 3 weeks with carboplatin (with a target area under the concentration versus time curve of 5 mg min/ml using the Calvert formula on day 1) plus irinotecan (50 mg/m(2) on days 1 and 8). From May 2000 to January 2002, 24 patients were eligible. None of the 22 patients achieved a complete response, but 15 achieved a partial response with an overall response rate of 68.2% (95% confidence interval, 45.1-86.1%). In 13 patients with sensitive disease, the response rate was 92.3% (95% confidence interval, 64.0-99.8%). The median survival time (MST) was 194 days (range 27-605 days). The MST did not differ significantly between patients with sensitive disease (245 days) and those with refractory disease (194 days, P=0.88). One patient died of treatment-related sepsis. Grade 3-4 hematologic toxicities included leukopenia in 58% of patients, neutropenia in 63%, thrombocytopenia in 58%, and anemia in 67%. Grade 3 diarrhea developed in 21% of patients and grade 3-4 infection in 13%. No patients had grade 4 diarrhea or grade 3-4 nausea and vomiting. This regimen is effective and well tolerated in patients with relapsed or refractory SCLC. However, the search for even more active regimens should be continued.

Relationship of circulating tumor cells to the effectiveness of cytotoxic chemotherapy in patients with metastatic non-small-cell lung cancer.

The aim of this study was to investigate the relationship of the number of circulating tumor cells (CTCs) with the effectiveness of cytotoxic chemotherapy in patients with metastatic non-small-cell lung cancer (NSCLC). We prospectively evaluated CTCs in the peripheral blood of patients with previously untreated metastatic NSCLC. From May 2008 through August 2010, 33 patients (23 men and 10 women; median age, 64 years; range, 46-74 years) were enrolled. All patients received combination chemotherapy with gemcitabine and carboplatin. The CTCs were captured from samples of peripheral blood with a semiautomated system using an antibody against epithelial cell adhesion molecule. Blood samples with one or more CTC per 7.5 ml were defined as positive. Of total 33 patients, 12 (36.4%) had positive CTCs and 5 (15.2%) had five or more CTCs before chemotherapy. There were no differences in response rates to cytotoxic chemotherapy between CTC-positive patients and CTC-negative patients. On the other hand, the rate of progressive disease in cytotoxic chemotherapy was significantly higher in CTC-positive patients (66.7%) than in CTC-negative patients (23.8%, p = 0.02). In conclusion, the number of CTCs could be a useful predictive factor for the effectiveness of cytotoxic chemotherapy in patients with metastatic NSCLC.

Irinotecan, a key chemotherapeutic drug for metastatic colorectal cancer.

Irinotecan hydrochloride is a camptothecin derivative that exerts antitumor activity against a variety of tumors. SN-38 produced in the body by carboxylesterase is the active metabolite of irinotecan. After irinotecan was introduced for the treatment of metastatic colorectal cancer (CRC) at the end of the last century, survival has improved dramatically. Irinotecan is now combined with 5-fluorouracil, oxaliplatin and several molecularly-targeted anticancer drugs, resulting in the extension of overall survival to longer than 30 mo. Severe, occasionally life-threatening toxicity occurs sporadically, even in patients in relatively good condition who have a low risk of chemotherapy-induced toxicity, often causing the failure of irinotecan-based chemotherapy. Clinical pharmacological studies have revealed that such severe toxicity is related to exposure to SN-38 and genetic polymorphisms in UDP-glucuronosyltransferase 1A1 gene. The large inter- and intra-patient variability in systemic exposure to SN-38 is determined not only by genetic factors but also by physiological and environmental factors. This review first summarizes the roles of irinotecan in chemotherapy for metastatic CRC and then discusses the optimal dosing of irinotecan based on the aforementioned factors affecting systemic exposure to SN-38, with the ultimate goal of achieving personalized irinotecan-based chemotherapy.

Genetic testing for UGT1A1*28 and *6 in Japanese patients who receive irinotecan chemotherapy

Polymorphisms of the UDP-glucuronosyltransferase (UGT) 1A1 gene, such as UGT1A1*28 and UGT1A1*6, can cause severe neutropenia and diarrhea in patients who receive irinotecan [1, 2]. Homozygosity for UGT1A1*28 is associated with less efficient glucuronidation of SN-38, the active metabolite of irinotecan, resulting in increased plasma SN-38 concentrations. Four pharmacogenetic trials have demonstrated an association between UGT1A1*28 genotype and irinotecan-induced hematologic toxicity, diarrhea, or both [3]. In response to these findings, the United States Food and Drug Administration has approved genetic testing for UGT1A1*28 and recommends that the initial dose of irinotecan is reduced by at least one level in patients who are homozygous for UGT1A1*28, albeit the effectiveness of such testing remains to be confirmed prospectively. UGT1A1*6 is also associated with severe irinotecan-related toxicity [4]. Given that the area under the time versus concentration curve ratio (SN-38 glucuronide/SN-38) seen in patients homozygous for UGT1A1*28 and *6 are almost equal [4], the impact of these variants on glucuronidation capacity of UGT1A1 for SN-38 is almost the same. The distribution of genotypes associated with these polymorphisms varies considerably among ethnic groups. UGT1A1*28 is found in Japanese and whites, but the allele frequency in Japanese is lower than that in whites [2, 4]. UGT1A1*6 is found in Japanese, but not in whites [4]. Homozygosity for UGT1A1*28 or UGT1A1*6 and heterozygosity for both UGT1A1*6 and UGT1A1*28 are associated with severe irinotecan-related neutropenia in Japanese patients [1, 4]. The Ministry of Health, Labour and Welfare in Japan has therefore recently approved genetic testing for UGT1A1*28 and *6. The value of genetic testing for UGT1A1 depends on genotype frequency and the association of genetic variants with irinotecan-induced toxicity. The higher the frequency of toxicity-related polymorphisms, the greater is the number of patients who would benefit from genetic testing. Large prospective studies are needed to accurately estimate the distribution of UGT1A1 polymorphisms in a given population. We have carried out the largest prospective study to date, examining the distributions of UGT1A1*28 and UGT1A1*6 genotypes in 300 Japanese patients (male/female, 172 of 128) with various solid tumors (200 colorectal, 43 gastric, 15 ovarian, 14 breast, 10 lung, and 18 others). All patients gave written informed consent, and the study protocol was approved by the Institutional Review Board of Saitama Medical University. Genotyping was carried out as described elsewhere [5]. UGT1A1*28 and UGT1A1*6 were in Hardy–Weinberg equilibrium (P > 0.05). Only 2 of 300 patients were UGT1A1*28 homozygotes (0.7%) (Table 1). The frequency of homozygosity for UGT1A1*28 was much lower than that in other prospective studies in Japan (2.3%, 4 of 176) [4]. The frequency of UGT1A1*6 homozygosity was 5.7% (Table 1), higher than that reported previously (2.8%) [4]. Eleven patients were both heterozygous for UGT1A1*6 and UGT1A1*28 (3.7%). The combined frequency of patients with two ‘risk alleles’ (i.e. *28/*28, *6/*6, and *6/*28) was 10.1% (95% confidence interval, 6.8% to 14.0%). Such patients might be at increased risk for irinotecan-related neutropenia. Given the genotype frequencies of UGT1A1*28 and UGT1A1*6, genetic testing for UGT1A1 might not be essential for identifying homozygotes for UGT1A1*28, but useful for identifying homozygotes for UGT1A1*6 as well as heterozygotes for UGT1A1*6 and UGT1A1*28, thereby avoiding severe irinotecan-induced toxicity in Japanese patients. The present results and considerations are likely to have application across East Asia. Prospective evaluations of genetic testing for UGT1A1 polymorphisms, encompassing both medical aspects and cost effectiveness, appear to be warranted, especially in East Asian countries including Japan. Table 1. Genotype frequencies of UGT1A1*28 and UGT1A1*6 in Japanese

Enhancement of sensitivity to tumor necrosis factor α in non-small cell lung cancer cells with acquired resistance to gefitinib

Tumor cells that have acquired resistance to gefitinib through continuous drug administration may complicate future treatment. To investigate the mechanisms of acquired resistance, we established PC-9/ZD2001, a non-small-cell lung cancer cell line resistant to gefitinib, by continuous exposure of the parental cell line PC-9 to gefitinib. After 6 months of culture in gefitinib-free conditions, PC-9/ZD2001 cells reacquired sensitivity to gefitinib and were established as a revertant cell line, PC-9/ZD2001R. PC-9/ZD2001 cells showed collateral sensitivity to several anticancer drugs (vinorelbine, paclitaxel, camptothecin, and 5-fluorouracil) and to tumor necrosis factor α (TNF-α). Compared with PC-9 cells, PC-9/ZD2001 cells were 67-fold more sensitive to TNF-α and PC-9/ZD2001R cells were 1.3-fold more sensitive. Therefore, collateral sensitivity to TNF-α was correlated with gefitinib resistance. PC-9/ZD2001 cells expressed a lower level of epidermal growth factor receptor (EGFR) than did PC-9 cells; this down-regulation was partially reversed in PC-9/ZD2001R cells. TNF-α-induced autophosphorylation of EGFR (cross-talk signaling) was detected in all three cell lines. However, TNF-α-induced Akt phosphorylation and IκB degradation were observed much less often in PC-9/ZD2001 cells than in PC-9 cells or PC-9/ZD2001R cells. Expression of the inhibitor of apoptosis proteins c-IAP1 and c-IAP2 was induced by TNF-α in PC-9 and PC-9/ZD2001R cells but not in PC-9/ZD2001 cells. This weak effect of EGFR on Akt pathway might contribute to the TNF-α sensitivity of PC-9/ZD2001 cells. These results suggest that therapy with TNF-α would be effective in some cases of non-small-cell lung cancer that have acquired resistance to gefitinib.

Delayed Elimination of SN-38 in Cancer Patients with Severe Renal Failure

This prospective study is designed to examine the effects of severe renal failure on the pharmacokinetics of irinotecan. The pharmacokinetics of irinotecan, 7-ethyl-10-hydroxycamptothecin (SN-38), and SN-38 glucuronide (SN-38G) in three cancer patients with severe renal failure [creatinine clearance (Ccr) ≤20 ml/min] who were undergoing dialysis and received 100 mg/m2 irinotecan as monotherapy were prospectively compared with those in five cancer patients with normal renal function (Ccr ≥60 ml/min). To ensure that the subjects had similar genetic backgrounds of UDP-glucuronosyltransferase (UGT) 1A1, patients with UGT1A1*1/*1, *1/*6, or *1/*28 were enrolled. The estimated terminal elimination rate constant of SN-38 in patients undergoing dialysis was approximately one tenth of that in patients with normal renal function (P = 0.025). Approximately 50% of SN-38 was dialyzed with a 2.1-m2 dialysis membrane, whereas 27% was dialyzed with a 1.5-m2 membrane. Our results showed that the elimination of SN-38 was significantly delayed in patients with severe renal failure compared with patients with normal renal function. We demonstrated that SN-38 was partly dialyzed.

Patient satisfaction with sedation for flexible bronchoscopy

Background and objective:  Patient satisfaction with health care has increasingly been recognized as an important health outcome, but few studies have examined patient satisfaction with flexible bronchoscopy (FB). The purpose of this study was to assess patient satisfaction with FB conducted under conscious sedation and to identify the aspects of the procedure related to patient satisfaction.

Regimen Selection for First-line FOLFIRI and FOLFOX Based on UGT1A1 Genotype and Physical Background is Feasible in Japanese Patients with Advanced Colorectal Cancer

OBJECTIVE We examined the feasibility of regimen selection for first-line irinotecan, 5-fluorouracil and leucovorin or oxaliplatin, 5-fluorouracil and leucovorin in Japanese patients with advanced colorectal cancer based on UDP-glucuronosyltransferase 1A1 genotype as well as physical status of patients related to diarrhea. METHODS As first-line irinotecan, 5-fluorouracil and leucovorin is a little bit superior to oxaliplatin, 5-fluorouracil and leucovorin with respect to efficacy and toxicity, patients without risk factors of irinotecan-induced toxicity were first assigned to irinotecan, 5-fluorouracil and leucovorin. Patients with UDP-glucuronosyltransferase 1A1 28/ 28, 6/ 6, 28/ 6 or 28/ 27 and those with ascites, peritoneal dissemination or diarrhea first received oxaliplatin, 5-fluorouracil and leucovorin to avoid the irinotecan-induced neutropenia and diarrhea, respectively. We retrospectively evaluated the feasibility of this strategy by assessing toxicity and total progression-free survival in first- and subsequent second-line therapies in all patients studied. RESULTS In the first-line irinotecan, 5-fluorouracil and leucovorin (n = 61), Grade 4 neutropenia, febrile neutropenia and Grade 3 diarrhea occurred in 8.2, 3.3 and 3.3% of patients, respectively. In the first-line oxaliplatin, 5-fluorouracil and leucovorin (n = 26), Grade 4 neutropenia, febrile neutropenia, Grade 3 thrombocytopenia and Grade 3 neuropathy were observed in 11.5, 3.8, 3.8 and 7.7% of patients, respectively. In the second-line oxaliplatin, 5-fluorouracil and leucovorin (n = 38), Grade 3 diarrhea occurred in 2.6% of patients. In the second-line irinotecan monotherapy (n = 11), Grade 4 or febrile neutropenia occurred in 18% of patients and Grade 3 diarrhea in 9.1% of patients. In second-line S-1 (n = 9), Grade 3 anemia occurred in 2 patients. Median total progression-free survival in all 87 patients was 11.5 months. CONCLUSIONS Present regimen selection strategy would be feasible, since it causes less toxicity and similar efficacy comparing to previous studies. Determination of appropriate reduced dose in the second-line irinotecan monotherapy or other standard second-line therapy for patients with high-risk to irinotecan-induced toxicity might make this strategy more effective.

A Phase I Study of Infusional 5-Fluorouracil, Leucovorin, Oxaliplatin and Irinotecan in Japanese Patients with Advanced Colorectal Cancer Who Harbor UGT1A1*1/*1,*1/*6 or *1/*28

Objective: To evaluate the safety and efficacy of combination chemotherapy with 5-fluorouracil (5-FU), leucovorin, irinotecan and oxaliplatin (FOLFOXIRI) in Japanese patients with advanced colorectal cancer. Methods: This phase I dose-finding study was designed to determine the maximum tolerated dose (MTD), recommended dose (RD) or both of FOLFOXIRI. Patients with UDP-glucuronosyltransferase (UGT) 1A1*6/*6, *28/*28 and *6/*28 genotypes were excluded, because these UGT1A1 genotypes are linked to severe neutropenia in Japanese. Results: A total of 10 Japanese patients with advanced colorectal cancer were studied. The MTD of FOLFOXIRI in these Japanese patients was 165 mg/m2 irinotecan, 85 mg/m2 oxaliplatin and 2,400 mg/m2 5-FU. Accordingly, the RD of FOLFOXIRI was determined to be 150 mg/m2 irinotecan, 85 mg/m2 oxaliplatin and 2,400 mg/m2 5-FU. Toxic effects, evaluated until the completion of 4 cycles, were manageable. Grade 3–4 neutropenia occurred in 27% of cycles, but there was no febrile neutropenia. Among the 9 assessable patients, the objective response rate was 89%. Conclusions: We thus determined the RD of FOLFOXIRI in Japanese patients with advanced colorectal cancer who do not have UGT1A1*28/*28, *6/*6 or *6/*28 genotypes. Our results indicate that FOLFOXIRI is a well-tolerated regimen for these Japanese patients.

Clinical and Economic Evaluation of First-line Therapy with FOLFIRI or Modified FOLFOX6 for Metastatic Colorectal Cancer

OBJECTIVE Recently, significant progress in treatment of metastatic colorectal cancer has been achieved. Either FOLFIRI (fluorouracil, leucovorin and irinotecan) or modified FOLFOX6 (fluorouracil, leucovorin and oxaliplatin, oxaliplatin dose 85 mg/m(2)) is selected as first-line therapy in clinical practice in Japan. However, economic burden of colorectal cancer is considerable. METHODS Analysis was made for all patients who were treated with FOLFIRI or modified FOLFOX6 for metastatic colorectal cancer. Regimen of FOLFIRI was compared with modified FOLFOX6 under consideration from clinical and economic standpoints. Progression free survival, response, toxicity and cancer care cost in patients with metastatic colorectal cancer was analyzed. Direct costs based on the fee schedule of the Japanese national health insurance were calculated. RESULTS Median progression free survival was 7.7 months for FOLFIRI versus 8.4 months for modified FOLFOX6 (P = 0.48). Overall cost for first four cycles was yen756 284 for FOLFIRI and yen1 081 162 for modified FOLFOX6 (P < 0.0001). All grade alopecia was significantly more frequent with FOLFIRI than with modified FOLFOX6 (P = 0.04). All grade neuropathy was more observed with modified FOLFOX6 than FOLFIRI (P = 0.0002). CONCLUSIONS FOLFIRI is inexpensive in the initial stage of treatment which a number of patients can receive chemotherapy than modified FOLFOX6 as first-line therapy for metastatic colorectal cancer in Japanese national insurance system.