Why not standard practice guidelines in Japan?

The issue of medical practice guidelines has attracted the attention of doctors and health care professionals in Western countries since the middle 1980s. Such guidelines aim to assist in clinical decision-making in order to reduce variations in care and unnecessary costs for delivered health care service, and to improve the outcomes of medical care. Strangely, however, there is no interest or attention given to this topic in the medical and health care fields in Japan. As the president of the 71st Japanese Gastric Cancer Association, the author hopes to generate interest in this topic by opening a symposium at the annual meeting of the JGCA this year. As an introduction to this session, the present paper provides a short review of medical practice guidelines, their development cycle, and their advantages and disadvantages.     

The cyclin-dependent kinase inhibitor p27 as a prognostic factor in advanced non-small cell lung cancer: its immunohistochemical evaluation using biopsy specimens

The expression of p27, which is known as a cyclin-dependent kinase inhibitor, on surgically resected specimens has considerable value for the prognosis of non-small cell lung cancer (NSCLC) patients. We immunohistochemically investigated the expression of the p27 protein in the biopsy specimens taken from 69 advanced NSCLC patients and assessed its clinical value. There was no significant correlation between p27 positivity and clinical parameters, including sex, age, histological type, clinical stage, smoking index and performance status. Furthermore, p27 positivity was not associated with response to chemotherapy. However, the Kaplan-Meier curve demonstrated that low p27 expression was significantly related to poor prognosis (P = 0.0019, by the log-rank test). Using multivariate analysis, p27, age and serum total protein level were found to be the independent prognostic parameters. The p27 positivity in the biopsy specimens of advanced NSCLC appears to be a useful prognostic marker.     

Prognostic significance of the PC10 index for patients with stage II and III oesophageal cancer treated with radiotherapy

The monoclonal antibody PC10 is used for immunohistochemical staining of the proliferating cell nuclear antigen (PCNA). The percentage of PC10-positive cancer cells is defined as the PC10 index. We evaluated the relationship between the PC10 index in pretreatment endoscopic biopsies and the prognoses of 47 patients with Stage II-III oesophageal squamous cell carcinoma treated with radiotherapy. The patients with a PC10 index > 40% had significantly poorer prognoses than the other patients (p = 0.0007). Proportional hazards model analysis indicated that only the PC10 index was a prognostic factor (p = 0.0009). The patient group of complete responders showed significantly lower PC10 indices compared to patients with a partial response or no change (p = 0.049). The PC10 index can be a good predictive indicator of the prognosis in patients with Stage II-III oesophageal cancer treated with radiotherapy.     

Induction of cell-cycle arrest and apoptosis by a novel retinobenzoic-acid derivative, TAC-101, in human pancreatic-cancer cells

In this study, we investigated the effect of a novel retinobenzoic acid, 4-[3,5-bis (trimethylsilyl) benzamido] benzoic acid (TAC-101), on the growth of 4 human pancreatic-cancer cell lines; BxPC-3, MIAPaCa-2, CFPAC-1 and AsPC-1. TAC-101 significantly inhibited the proliferation of BxPC-3 and MIAPaCa-2 cells in a time- and concentration-dependent manner, but not the proliferation of AsPC-1 cells. Furthermore, the anti-proliferative effects of TAC-101 on BxPC-3 and MIAPaCa-2 cells were stronger than those of all-trans retinoic acid. Flow-cytometric analyses indicated that treatment of BxPC-3 with TAC-101 strongly induces cell-cycle arrest at the G1 phase. The cell-cycle arrest induced by TAC-101 was accompanied by reduction of retinoblastoma-gene product (RB) phosphorylation and an increase of 2 cyclin-dependent kinase (CDK) inhibitors, p21(WAF1/Cip1) (p21) and p27Kip1 (p27). TAC-101 also caused a decrease in cyclin A and thymidylate synthase, which are E2F-regulated gene products. No changes were observed in the expression of cyclin D1, cyclin E on CDK2. In addition, Hoechst staining, gel electrophoresis and flow-cytometric analysis indicated that a marked reduction in the number of BxPC-3 cells with TAC-101 was related to the induction of apoptosis. Our results suggest that TAC-101 inhibits the growth of certain pancreatic-cancer cells by means of G1-phase cell-cycle arrest resulting from the reduction of RB phosphorylation and the up-regulation of p21 and p27 as well as the induction of apoptosis. TAC-101 may therefore be a useful agent for new therapeutic strategies focusing on inhibition of pancreatic-cancer-cell proliferation.     

Colonic hamartoma development by anomalous duplication in Cdx2 knockout mice.

To determine the biological role of caudal-like homeobox gene CDX2, we constructed knockout mice in which its mouse homologue Cdx2 was inactivated by homologous recombination, placing a bacterial lacZ gene under the control of the Cdx2 promoter. Although the homozygous mutants died in utero around implantation, the heterozygotes were viable and fertile and expressed lacZ in the caudal region in early embryos and in the gut tissues in adults. The heterozygotes developed cecal and colonic villi by anteriorization and formed hamartomatous polyps in the proximal colon. The hamartoma started to develop at 11.5 days of gestation as an outpocket of the gut epithelium, which ceased to express the remaining Cdx2 allele. The outpocket then expanded as a partially duplicated gut but was contained as a hamartoma after birth. In adult mice, these hamartomas grew very slowly and took a benign course. None of them progressed into invasive adenocarcinomas, even at 1.5 years of age. Whereas the cecal and colonic villi expressed lacZ, the hamartoma epithelium did not, nor did it express Cdx2 mRNA from the wild-type allele. However, genomic DNA analysis of the polyp epithelium did not show a loss of heterozygosity of the Cdx2 gene, suggesting a mechanism of biallelic Cdx2 inactivation other than loss of heterozygosity. These results indicate that the Cdx2 haploin-sufficiency caused cecal and colonic villi, whereas the biallelic inactivation of Cdx2 triggered anomalous duplications of the embryonic gut epithelium, which were contained as hamartomas after birth.     

Adoptive immunotherapy for advanced cancer patients using in vitro activated cytotoxic T lymphocytes

BACKGROUND AND OBJECTIVES: We evaluated the clinical efficacy of adoptive immunotherapy using in vitro activated cytotoxic T lymphocytes (CTL) in the treatment of patients with advanced cancer. METHODS: CTL were induced with the mixed lymphocyte and tumor cell culture method, in which lymphocytes isolated from patient peripheral blood mononuclear cells were mixed with inactivated autologous tumor cells. Activated lymphocytes were administered intravenously to 11 patients once every 2 weeks for 10 weeks (i.e., 5 doses). RESULTS: Tumor reduction and decreased tumor marker were observed in 4 patients. Notably, successful CTL induction was identified in all of these patients. In patients who did not show induction of CTL response, a decreased proportion of lymphocytes, especially CD8(+) cells, and increased levels of CD14(+) cells were frequently observed. Fluorescence-activated cell sorter analysis indicated that expression of HLA class I and costimulatory factor B7-1 molecules was diminished on tumor cells. This was partly recovered with interferon-gamma, which resulted in successful induction of a CTL response. CONCLUSIONS: It was suggested that in vitro CTL induction is difficult in patients with advanced cancer. However, once the cells were induced successfully, some favorable clinical effects were seen by the adoptive transfer of such cell populations.     

Cisplatin (CDDP) sensitizes human osteosarcoma cell to Fas/CD95-mediated apoptosis by down-regulating FLIP-L expression

The mechanisms of escape from Fas/CD95-mediated apoptosis induced by immunosurveillance(NK cells and T cells) in tumor cells are correlated to tumorigenicity. Human osteosarcoma cell MG-63 constitutively expressed cell surface Fas antigen but was resistant to apoptosis by Fas stimulation. However, suboptimal dose of cisplatin(CDDP) could sensitize MG-63 cells to Fas-mediated apoptosis without up-regulation of cell-surface Fas antigen. Western blotting analysis showed that MG-63 cells constitutively expressed FLICE inhibitory protein long form(FLIP-L), which was a novel anti-apoptotic protein and had a potency of tumorigenicity. CDDP down-regulated FLIP-L in a time-dependent manner in MG-63 cells but did not influence expression of other anti-apoptotic molecules such as XIAP, c-IAP-1, c-IAP-2, FADD or pro-caspase-8. Moreover, antisense oligonucleotide to FLIP-L confirmed that down-regulation of FLIP-L induced sensitization to Fas-mediated apoptosis. These findings suggest that FLIP-L contributes to resistance to Fas-mediated apoptosis in MG-63 cells, and sensitization to Fas-mediated apoptosis by CDDP can be a new application of immune therapy.