肿瘤干细胞标志物与胃癌关系的研究进展

肿瘤干细胞（cancer stem cell,CSCs）是理论认为肿瘤中存在一小部分细胞具有自我更新和多向分化的潜能,具有特异性表面标志的细胞.目前已经从乳腺癌、结直肠癌、皮肤癌等多种恶性肿瘤中鉴定分离出了各自的肿瘤干细胞标志物.本文就与胃癌相关的干细胞标志物进行综述.     

An EGFR inhibitor enhances the efficacy of SN38, an active metabolite of irinotecan, in SN38-refractory gastric carcinoma cells

Background:

Acquired drug resistance to irinotecan is one of the significant obstacles in the treatment of advanced gastric cancer. This study was performed to clarify the effect of epidermal growth factor receptor (EGFR) inhibitors in combination with SN38, an active metabolite of irinotecan, on the proliferation of irinotecan-refractory gastric cancer.

Methods:

Two irinotecan-resistant gastric cancer cell lines, OCUM-2M/SN38 and OCUM-8/SN38 were, respectively, established by stepwise exposure to SN38 from the parent gastric cancer cell lines OCUM-2M and OCUM-8. The combination effects of two EGFR inhibitors, gefitinib and lapatinib, with SN38 on proliferation, apoptosis, and cell cycle on gastric cancer cells were examined.

Results:

Gefitinib or lapatinib showed synergistic anti-tumour effects against OCUM-2M/SN38 and OCUM-8/SN38 cells when used in combination with SN38, but not against OCUM-2M or OCUM-8 cells. SN38 increased the expression of EGFR and HER2 in OCUM-2M/SN38 and OCUM-8/SN38 cells. The combination of an EGFR inhibitor and SN38 significantly increased the levels of apoptosis-related molecules, caspase-6, p53, and DAPK-2, and resulted in the induction of apoptosis of irinotecan-resistant cells. The EGFR inhibitors increased the S-phase and decreased the UGT1A1 and ABCG expression in irinotecan-resistant cells. The SN38 plus Lapatinib group more effectively suppressed in vivo tumour growth by OCUM-2M/SN38 cells than either alone group.

Conclusion:

The combination treatment with an EGFR inhibitor and irinotecan might produce synergistic anti-tumour effects for irinotecan-refractory gastric cancer cells. The regulation of SN38 metabolism-related genes and cell cycle by EGFR inhibitors might be responsible for the synergism.     

Phase II study of docetaxel and irinotecan combination chemotherapy in metastatic gastric carcinoma

The current treatment for metastatic gastric cancer (MGC) consists of cisplatin and/or fluorouracil (5-FU) based combination chemotherapy, but cisplatin-based regimens are associated with considerable toxicity. We evaluated the efficacy and safety of a noncisplatin-, non-5-FU-containing regimen, docetaxel/irinotecan in MGC. Chemo-naive patients with MGC received docetaxel (30 mg m(-2)) and irinotecan (70 mg m(-2)) on days 1 and 8 every 3 weeks. The 48 eligible patients (median age 56 years) received a median of four cycles of docetaxel/irinotecan (range 1-18). Of the 46 patients in whom efficacy could be evaluated, 21 showed a partial response (response rate=45.7%; 95% confidence interval (CI) 31.3-60.1%). At a median follow-up of 15.0 months, the median time to progression was 4.5 months (95% CI 3.8-5.2 months) and overall survival was 8.2 months (95% CI, 5.8-10.6 months). Grade 3/4 neutropenia developed in 57.4% of patients, and febrile neutropenia/neutropenic infection in 19.1%. Nonhaematological toxicities were moderate; grade 3/4 diarrhoea occurred in 19.1% of patients, however, was manageable by a dose reduction. There was one possible treatment-related death. In conclusion, weekly docetaxel/irinotecan is a promising outpatient regimen in MGC, with appropriate dose modification.     

TRAIL-expressing mesenchymal stem cells kill the putative cancer stem cell population

Background:

Tumours contain stem-like, side population (SP) cells, which have increased tumorigenic potential, resistance to traditional therapies and may be responsible for treatment failures and relapse in patients.

Methods:

Mesenchymal stem cells (MSCs) were engineered to express the apoptotic ligand, TNF-related apoptosis-inducing ligand (TRAIL). Squamous (H357) and lung (A549) cancer cell lines were sorted into side and non-side populations (non-SP) by Hoechst flow cytometry. The survival and growth of both SP and non-SP cancer populations, in conjunction with TRAIL-expressing MSCs and mitoxantrone chemotherapy, were assessed by flow cytometry and colony forming ability.

Results:

Mesenchymal stem cells expressing TRAIL migrate to tumours and reduce the growth of primary cancers and metastases. This report demonstrates that these cells cause apoptosis, death and reduced colony formation of the SP of squamous and adenocarcinoma lung cancer cells and are synergistic when combined with traditional chemotherapy in apoptosis induction.

Conclusions:

The sensitivity of putative cancer stem cells to TRAIL-expressing MSCs, suggests their possible role in the prevention of cancer relapse.     

骨髓间充质干细胞体内外对胃癌细胞的趋向性

目的:探讨人骨髓间充质干细胞(human bone marrow-derived mesenchymal stem cell,hBMSC)对胃癌细胞的趋化性,为将MSC研发成为胃癌基因治疗载体提供实验依据.方法:骨髓培养法分离培养hBMSC并进行流式细胞术鉴定.Transwell实验检测hBMSC对胃癌MKN45细胞和人成纤维细胞(human fibroblast,hFB)的趋化能力.建立MKN45细胞裸鼠移植瘤模型,感染Lenti-EGFP(MOI为50)的hBMSC或hFB细胞经尾静脉注射入荷瘤小鼠,荧光显微镜下观察移植瘤组织及各脏器GFP的表达.结果:培养第3代的hBMSC细胞CD44、CD105阳性率为(96.7±1.84)％、(98.1±0.95)％,而CD34、CD45表达阴性.hBMSC细胞向MKN45细胞的趋化能力明显强于胃上皮细胞GES-1组及空白对照细胞[(239.5-54.3)vs(43.57±4.6)、(37.3±4.7)个,P＜0.01],且hBMSC向MKN45细胞的趋化能力明显强于hFB细胞向MKN45细胞的趋化能力[(239.5 ±54.3)vs(27.7 ±16.7),P＜0.01].与hFB相比,hBMSC对胃癌移植瘤组织具有明显趋向性;hBMSC组移植瘤组织内可见GFP表达,移植瘤小鼠部分肝脏(20％)及肺脏(20％)有GFP表达,但较移植瘤组织内GFP表达率和强度均低(P＜0.05).结论:hBMSC在体内外对胃癌细胞均有特异性趋化作用,有望研发为胃癌基因治疗的良好载体.     

胃癌细胞中CD44阳性细胞具有肿瘤干细胞特征

目的:在原位移植瘤模型上验证CD44+胃癌细胞的肿瘤干细胞特性.方法:选取MKN-45胃癌细胞株,通过流式细胞仪分选为CD44+和CD44-两组,以未分选的MKN-45胃癌细胞为对照.体外部分,通过MTT法和克隆形成实验验证CD44+胃癌细胞体外增殖能力,通过Transwell实验验证其侵袭力.体内部分,将上述细胞通过原位移植法接种至裸鼠,同等条件下饲养8周后处死裸鼠,检验其成瘤率;分离肝脏,检测肝转移瘤数目;H-E染色观察胃肿瘤和肝转移瘤形态;通过免疫荧光法检测两处肿瘤CD44+细胞数量.结果:CD44+胃癌细胞相比CD44‘胃癌细胞具有明显增强的细胞增殖力(P＜0.01)和侵袭力(P＜0.01),更容易成瘤且更容易发生转移(P＜0.05),但和MKN-45未分选组相比差异无统计学意义(P＞0.05).不论是在原发肿瘤还是转移瘤中,CD44+胃癌细胞均能产生CD44‘细胞,但后者不能产生CD44+细胞.结论:CD44+ MKN-45胃癌细胞相比CD44-胃癌细胞具备更强的增殖力和侵袭力、更容易成瘤和发生转移,符合肿瘤干细胞部分特征,值得进一步研究.     

ABCG2基因在胃癌组织中的表达(英文)

Objective:The aim of this study was to investigate the expression of ABCG2 in human gastric carcinoma and its clinical significance.Methods:Expression of ABCG2 was examined with immunohistochemical technique in the specimens from 45 gastric carcinoma tissues and 30 surrounding normal tissues.The mRNA expression of ABCG2 was measured by RT-PCR and real-time quantitative PCR in 30 cases of gastric carcinoma and normal gastric mucosa, respectively.Results:ABCG2 expression was observed in 28 of 45(62.2%) cases ...     

HGF、c-Met及p-Erk蛋白在胃癌组织中的表达及意义

目的:本研究主要探讨肝细胞生长因子(hepatocyte growth factor, HGF)和肝细胞生长因子受体(mesenchymal epithelial transition factor, c-Met)及下游信号通路分子磷酸化的Erk（p-Erk）表达与临床病理参数间的关系及其意义。研究HGF、c-Met、p-Erk表达与胃癌生存期的相关性。方法:应用免疫组化方法检测71例胃癌患者行手术治疗后切除的肿瘤组织及53例癌旁正常组织中HGF、c-Met、p-Erk的三者表达状况。分析它们与胃癌临床病理参数间的关系及三者在胃癌组织中表达的相关性,并分析其与胃癌患者的预后生存间存在的关联。结果:HGF、c-Met、p-Erk在胃癌黏膜组织中相对于癌旁正常组织呈高表达状态,且差异有统计学意义(P＜0.05)。三者与性别、年龄大小及主癌所在部位、分化程度未表现出相关性(P＞0.05)。而它们与肿瘤的大小、浸润深度、淋巴结转移、术后复发转移显著相关(P＜0.05)。在胃癌组织中,HGF 与c-Met的表达呈正相关(r=0.576,P=0.001),p-Erk与 HGF 的表达呈正相关(r=0.666,P=0.003),同时p-Erk与 c-Met 的表达呈正相关(r=0.587,P=0.001)。生存分析提示三者的阳性表达明显缩短了胃癌患者术后5年的生存期。结论:HGF、c-Met、p-Erk在胃癌黏膜组织中的表现为高表达,三者与胃恶性肿瘤的发病及进展过程联系密切,可能参与胃恶性肿瘤的发生及发展。     

上调miR-200a表达对人肝癌细胞MHCC97中边缘群细胞干细胞特性的影响

目的:探讨转染miR-200a mimics对人肝癌细胞系MHCC97中边缘群细胞(SP)干细胞特性的影响。方法:利用流式细胞技术从MHCC97细胞中分离出SP细胞。转染组为应用脂质体介导转染miR-200a mimics的SP细胞,对照组为未接受转染的SP细胞。采用实时荧光定量RT-PCR检测两组SP细胞miR-200a的表达情况。四甲基偶氮唑盐(MTT)和软琼脂克隆形成实验检测细胞增殖情况。Transwell小室检测细胞迁移能力。裸鼠成瘤实验检测细胞体外成瘤能力。结果:转染miR-200a mimics可明显上调SP细胞miR-200a的表达。MTT结果显示转染组SP细胞的增殖能力明显低于对照组(P<0.05),转染组软琼脂中克隆形成率(24.70±5.54)%明显低于对照组(51.63±7.11)%（P<0.05)。Transwell实验显示转染组细胞穿膜数为(18.52±4.27)个,明显少于对照组(63.34±7.41)个(P<0.05)。裸鼠成瘤实验中转染组成瘤数(1/8)也低于对照组(8/8)（P<0.05)。结论:上调人肝癌细胞系MHCC97中SP细胞miR-200a的表达,能够抑制SP细胞的增殖和迁移,降低体外成瘤能力,即抑制SP细胞的干细胞特性。     

Phase II study of capecitabine and irinotecan combination chemotherapy in patients with advanced gastric cancer

The present study was conducted to evaluate the efficacy and safety of a combination regimen of capecitabine plus irinotecan in patients with advanced gastric cancer. Patients with previously untreated metastatic or recurrent, measurable gastric cancer received oral capecitabine 1000 mg m(-2) twice daily from day 1 to 14 and intravenous irinotecan 100 mg m(-2) on days 1 and 8, based on a 3-week cycle. Forty-one patients were enrolled in the current study, among whom 38 were assessable for efficacy and 40 assessable for toxicity. Three complete responses and 16 partial responses were confirmed, giving an overall response rate of 46.3%. At a median follow-up of 269 days, the median time to progression and overall survival were 5.1 and 8.6 months, respectively. Grade 3/4 neutropenia occurred in four patients and grade 3 febrile neutropenia was observed in two patients. Grade 3 diarrhoea and grade 2 hand-foot syndrome occurred in six patients and eight patients, respectively. The combination of capecitabine and irinotecan was found to be well tolerated and effective in patients with advanced gastric cancer. Accordingly, this regimen can be regarded as one of first-line treatment options for advanced gastric cancer.     

人胃癌CD90+干细胞可能影响胃癌的转移和患者的预后

目的： 分离并鉴定人胃癌细胞系SNU-5中的肿瘤干细胞,探讨人胃癌CD90+干细胞对胃癌转移和预后的影响。 方法： 无血清悬浮培养及PKH26染色确定SNU-5细胞系中是否存在肿瘤干细胞,流式细胞术分析SNU-5亲本及球体细胞中肿瘤干细胞标志物的表达,分选CD90+SNU-5细胞并进行体外生物学特征研究及SCID鼠致瘤实验。收集肿瘤医院腹部外科95例胃癌患者肿瘤病理标本,免疫组化方法检测胃癌组织中CD90的表达。 结果： SNU-5细胞无血清悬浮培养11 d后形成的细胞球体中存在单个PKH26阳性细胞。无血清悬浮培养可将CD90+SNU-5细胞富集6.1倍,且CD90可在球体细胞中与标示干细胞的PKH26共染。CD90+SNU-5细胞较CD90- SNU-5细胞和亲本SNU-5细胞具有更高的自我更新能力\[成球率（7.7±1.1）% vs (1.3±0.4)%、(1.8±0.3)%,均P<0.01\]和侵袭能力\[侵袭细胞数(283.3±30.2) vs (48.0±7.5)、(156.7±72)个,均P<0.01\]。CD90+SNU-5细胞在重症联合免疫缺陷（severe combined immune deficency,SCID）小鼠皮下接种2×102个细胞6周即可致瘤（1/6）,而接种2×104个CD90- SNU-5细胞10周才能致瘤（1/6）。95例胃癌患者组织中CD90的表达与胃癌的远处转移显著相关（P<0.01）,且CD90阳性胃癌患者的生存期明显短于CD90阴性的患者（P<0.01）。 结论： 人胃癌细胞系SNU-5中存在具有更强自我更新及侵袭能力的CD90+干细胞,人胃癌组织中CD90+干细胞数量与肿瘤的转移与患者生存期明显相关。     

干细胞标志物在卵巢癌SKOV3细胞侧群细胞中的表达

目的：检测干细胞相关标志物在卵巢癌SKOV3细胞系侧群（side population,SP）细胞和非侧群（Non-SP）细胞中的表达差异,确定卵巢癌干细胞特异性标志物。 方法： Hoechst 33342染色检测SKOV3细胞中SP细胞的比例,流式细胞术检测SKOV3细胞的SP和Non-SP细胞中干细胞标志物CD133、CD117、CD44、ABCG2、ALDH1 的表达情况,荧光定量PCR检测SP和Non-SP细胞中 ABCG2、ALDH2、NANOG、OCT4、SOX2、CD133、CD117 mRNA的表达水平。 结果： SKOV3细胞中SP细胞比例为(1.56±0.35)%。 ALDH1、ABCG2在SP细胞中表达率分别为（87.3±5.76）%、（29.48±4.43）%,在Non-SP的表达率分别为（5.32±0.47）%、（3.01±1.69）%,差异有统计学意义（ P <0.01）;CD44在这两种细胞亚群中的表达率均高于99%（ P >005）;CD133、CD117在这两种细胞亚群中均不表达。 ALDH1、ABCG2、 NANOG、OCT4和SOX2 mRNA在SP细胞中的表达分别是Non-SP细胞的21.03倍（ P =0.001）、3.14倍（ P =0.001）、23.94倍（ P =0.001）、10.73倍（ P =0.009）和21.46倍( P =0001), CD133、CD117 mRNA在两种细胞亚群中均不表达。 结论： 人卵巢癌细胞株SKOV3中存在SP细胞亚群, ALDH1、ABCG2和NANOG、OCT4、SOX2 mRNA可能是卵巢癌干细胞标志物,为诊断及治疗卵巢癌提供了潜在的靶点。     

Novel and efficient method for culturing patient-derived gastric cancer stem cells

Experimental techniques for patient-derived cancer stem-cell organoids/spheroids can be powerful diagnostic tools for personalized chemotherapy. However, establishing their cultures from gastric cancer remains challenging due to low culture efficiency and cumbersome methods. To propagate gastric cancer cells as highly proliferative stem-cell spheroids in vitro, we initially used a similar method to that for colorectal cancer stem cells, which, unfortunately, resulted in a low success rate (25%, 18 of 71 cases). We scrutinized the protocol and found that the unsuccessful cases were largely caused by the paucity of cancer stem cells in the sampled tissues as well as insufficient culture media. To overcome these obstacles, we extensively revised our sample collection protocol and culture conditions. We then investigated the following second cohort and, consequently, achieved a significantly higher success rate (88%, 29 of 33 cases). One of the key improvements included new sampling procedures for tumor tissues from wider and deeper areas of gastric cancer specimens, which allowed securing cancer stem cells more reproducibly. Additionally, we embedded tumor epithelial pieces separately in both Matrigel and collagen type-I as their preference to the extracellular matrix was different depending on the tumors. We also added a low concentration of Wnt ligands to the culture, which helped the growth of occasional Wnt-responsive gastric cancer stem-cell spheroids without allowing proliferation of the normal gastric epithelial stem cells. This newly improved spheroid culture method may facilitate further studies, including personalized drug-sensitivity tests prior to drug therapy.     

伊立替康联合替吉奥二线治疗晚期胃癌的临床观察

目的:观察伊立替康联合替吉奥二线治疗晚期胃癌的疗效和毒副反应。方法:53例晚期胃癌给予伊立替康180mg/m2,静脉滴注,d1;替吉奥60mg/m2,口服,分2次/d,第d1~14,21d为1个周期。至少治疗2个周期。结果:50例可评价疗效,其中CR 4例,PR 17例,SD 15例,PD 14例,总有效率为42%,疾病控制率72%。常见毒副反应为中性粒细胞减少、迟发性腹泻、恶心、呕吐等,多为Ⅰ-Ⅱ度。结论:伊立替康联合替吉奥二线治疗晚期胃癌疗效较好,毒副反应可耐受。     

原代胃癌干细胞CD44表达意义探讨

目的 肿瘤干细胞(cancer stem cells,CSCs)在恶性肿瘤的发生发展中起着重要作用,且是肿瘤耐药及复发的根源.本研究探讨CSCs表面标记蛋白CD44在分离及鉴定胃癌干细胞中的重要作用.方法 收集2015-11-06-2015-12 01华中科技大学同济医学院附属同济医院3例胃癌患者手术标本.首先采用胶原酶消化法获取胃癌细胞,部分细胞分别贴壁及悬浮培养,并采用免疫荧光及流式分析的方法检测胃癌球形体中CD44的表达情况.部分细胞采用流式细胞仪分选得到CD44+及CD44胃癌细胞,并通过无血清悬浮培养法比较两群细胞的球形体形成能力.结果 免疫荧光显示,CD44蛋白在球形体中高表达;流式分析发现,贴壁的原代胃癌细胞中CD44+细胞的比例为(30.73±7.6)％,而球形体中CD44+细胞的比例高达(56.4±5.58)％,差异有统计学意义,P=0.009.球形体形成实验结果表明,与CD44-细胞相比,CD44+胃癌细胞具有更强的球形体形成能力,1 000个CD44+及CD44-胃癌细胞分别形成(14.33±2.52)和(1.67±0.58)个球形体,差异有统计学意义,P=0.001.通过比较发现,球形体培养对胃癌干细胞的富集效率为0.3％,而CD44对胃癌干细胞的富集效率为1.4％.结论 CD44是胃癌干细胞的表面标记蛋白,其可能成为胃癌靶向治疗的可靠靶标.     

A FGFR2 inhibitor, Ki23057, enhances the chemosensitivity of drug-resistant gastric cancer cells

Aim

The aim of this study was to clarify the ability of a FGFR2 inhibitor, Ki23057, to enhance the chemosensitivity of drug-resistant gastric cancer cell lines when used in combination with chemotherapeutic drugs.

Materials and methods

Five cancer cell lines resistant to irinotecan (SN38), paclitaxel (PTX), etoposide (VP16), oxaliplatin (OXA), and gemcitabine (GEM) were respectively established from a parent gastric cancer cell line, OCUM-2M, and were named OCUM-2M/SN38, OCUM-2M/PTX, OCUM-2M/VP16, OCUM-2M/OXA, and OCUM-2M/GEM. The effects of the combination of Ki23057 with anticancer drugs on proliferation, apoptosis, and mRNA expression were examined.

Results

Ki23057 significantly decreased the IC₅₀ values of OCUM-2M/SN38, OCUM-2M/PTX, and OCUM-2M/VP16, but not those of OCUM-2M/OXA and OCUM-2M/GEM. Ki23057 significantly enhanced the apoptosis rates induced by chemotherapeutic drugs in both the drug-resistant cell lines and the parental cell line. Ki23057 decreased the ERCC1 expression level in OCUM-2M/SN38, OCUM-2M/PTX, and OCUM-2M/VP16. Ki23057 increased the p53 expression level in OCUM-2M/SN38 and OCUM-2M/PTX, but not in OCUM-2M/VP16.

Conclusion

The FGFR2 inhibitor Ki23057 might be therapeutically promising for treating drug-resistant gastric cancer cells, especially when used in combination with SN38, PTX, or VP16. The apoptosis process might be the main mechanism underlying the synergistic effect of these combinations. The ERCC1 and p53 genes may play an integral role in the synergism between Ki23057 and chemotherapeutic agents in drug-resistant cell lines.     

伊立替康联合替吉奥二线治疗晚期胃癌的临床观察

目的：观察伊立替康联合替吉奥二线治疗晚期胃癌的近期疗效和毒副反应。方法：27例晚期胃癌患者采用伊立替康270mg/ m2,静脉滴注,第1天;替吉奥60mg/ m2,分早、晚两次口服,第1-14天,21天为一个周期。结果：26例可评价疗效,其中 CR 1例,PR 8例,SD 8例,有效率34.6%,疾病控制率65.4%。常见毒副反应主要有恶心、呕吐、乏力、骨髓抑制、腹泻等,但多为 I/ II 度。结论：伊立替康联合替吉奥二线治疗晚期胃癌近期疗效较好,毒副反应可耐受。     

人前列腺癌细胞系DU 145中肿瘤干细胞样侧群细胞的分离

目的:分离人前列腺癌细胞系DU 145中的侧群(side population,SP)细胞,并初步分析其生物学特性。方法:采用荧光激活细胞分类(fluorescence activated cell sorting,FACS)技术,从DU 145细胞中分离出侧群细胞,并检测其比例;继而培养于无血清培养基中,观察其生长特性。采用反转录聚合酶链反应(RT-PCR)技术检测侧群细胞中ABCG2的表达水平。结果:DU 1 4 5细胞中存在含量极少的侧群细胞,比例约1.1%;培养于无血清培养基中成簇生长。和对应的母系DU 145细胞相比,DU 145侧群细胞的ABCG2表达增高。结论:人前列腺癌细胞系DU 145中存在具有肿瘤干细胞特性的侧群细胞。     

A phase II study of irinotecan with 5-fluorouracil and leucovorin in patients with previously untreated gastric adenocarcinoma

Background:A phase II study testing the safety and efficacyof irinotecan (CPT-11), 5-fluorouracil (5-FU), and leucovorin (LCV)was conducted in patients with advanced gastric adenocarcinomas. Patients and methods:Patients with metastatic or recurrentadenocarcinoma of the gastroesophageal junction (GEJ) or stomach wereentered onto this study. Previous chemotherapy for metastatic diseasewas not allowed. Treatment consisted of repeated 6-week cyclescomprising CPT-11 125 mg/m² intravenously (i.v.) followedimmediately by LCV 20 mg/m² i.v. and 5-FU 500mg/m² i.v., all given weekly for four weeks followed by atwo-week rest. Results:Thirty-eight patients wereenrolled and 36 eligible patients received protocol therapy. Grade3–5 toxicities consisted primarily of neutropenia (36%) anddiarrhea (28%). Neutropenic infection was observed in 14%of patients, with 3 (8%) dying of neutropenic sepsis. The overallresponse rate was 22% (95% confidence interval [CI]8.5% to 35.5%). Median survival was 7.6 months, and mediantime to progression was 4.4 months. Conclusion:Thisweekly regimen of CPT-11 with bolus 5-FU/LCV is active in patients withadvanced adenocarcinomas of the stomach or gastroesophageal junction.While rates of grade 3–4 neutropenia and diarrhea were similar tothose observed historically in patients receiving this regimen forcolorectal cancer, neutropenic fever/sepsis appeared to be morefrequent, and dose modifications were substantial. Future trials of thiscombination in patients with gastric cancer should decrease the absolutestarting drug doses and/or employ altered scheduling that betteraccommodates the pattern of toxicity.     

Phase I/II study of S-1 combined with irinotecan for metastatic advanced gastric cancer

A dose-escalation study of irinotecan (CPT-11) combined with S-1, an oral dihydropyrimidine dehydrogenase inhibitory fluoropyrimidine, was performed to determine the maximum-tolerated dose (MTD), recommended dose (RD), dose-limiting toxicities (DLTs), and objective response rate (RR) in advanced gastric cancer (AGC). S-1 was administered orally at 80 mg m-2 day-1 from day 1 to 14 of a 28-day cycle and CPT-11 was given intravenously on day 1 and 8 at an initial dose of 70 mg m-2 day-1, stepping up to 100 mg m-2. The treatment was repeated every 4 weeks, unless disease progression was observed. In the phase I portion, the MTD of CPT-11 was presumed to be 100 mg m-2, because 66.6% of patients (two of three) developed DLTs. All three patients at the initial RD of CPT-11 (90 mg m-2) experienced grade 4 haematological or grade 3 nonhaematological toxicities at second course, followed by the dose reduction of CPT-11 from the third course. Considering safety and the ability to continue treatment, the final RD was determined to be 80 mg m-2. In the phase II portion, 42 patients including seven patients in the final RD phase I portion were evaluated. The median treatment course was five (range: 1-13). The incidences of severe (grade 3-4) haematological and nonhaematological toxicities were 19 and 10%, respectively, but all were manageable. The RR was 62% (26 of 42, 95% confidence interval: 47.2-76.6%), and the median survival time was 444 days. Our phase I/II trial showed S-1 combined with CPT-11 is effective for AGC and is well tolerated, with acceptable toxicity.