Hirohiko Sakamoto

Glypican-3, overexpressed in hepatocellular carcinoma, modulates FGF2 and BMP-7 signaling.

The Glypican (GPC) family is a prototypical member of the cell‐surface heparan sulfate proteoglycans (HSPGs). The HSPGs have been demonstrated to interact with growth factors, act as coreceptors and modulate growth factor activity. Here we show that based on oligonucleotide array analysis, GPC3 was upregulated in hepatocellular carcinoma (HCC). By northern blot analysis, GPC3 mRNA was found to be upregulated in 29 of 52 cases of HCC (55.7%). By Western blot analysis carried out with a monoclonal anti‐GPC3 antibody we generated, the GPC3 protein was found to be overexpressed in 6 hepatoma cell lines, HepG2, Hep3B, HT17, HuH6, HuH7 and PLC/PRF/5, as well as 22 tumors (42.3%). To investigate the role of overexpressed GPC3 in liver cancer, we analyzed its effects on cell growth of hepatoblastoma‐derived cells. Overexpression of GPC3 modulated cell proliferation by inhibiting fibroblast growth factor 2 (FGF2) and bone morphogenetic protein 7 (BMP‐7) activity. An interaction of GPC3 and FGF2 was revealed by co‐immunoprecipitation, while GPC3 was found to inhibit BMP‐7 signaling through the Smad pathway by reporter gene assay. The modulation of growth factors by GPC3 may help explain its role in liver carcinogenesis. In addition, the ability of HCC cells to express GPC3 at high levels may serve as a new tumor marker for HCC.

Three DNA Methylation Epigenotypes in Human Colorectal Cancer

Purpose: Whereas the CpG island methylator phenotype (CIMP) in colorectal cancer associates with microsatellite instability (MSI)-high and BRAF-mutation(+), the existence of an intermediate-methylation subgroup associated with KRAS-mutation(+) is controversial, and suitable markers for the subgroup have yet to be developed. Our aim is to clarify DNA methylation epigenotypes of colorectal cancer more comprehensively. Experimental Design: To select new methylation markers on a genome-wide scale, we did methylated DNA immunoprecipitation-on-chip analysis of colorectal cancer cell lines and re-expression array analysis by 5-aza-2′-deoxycytidine/Trichostatin A treatment. Methylation levels were analyzed quantitatively in 149 colorectal cancer samples using matrix-assisted laser desorption/ionization–time-of-flight mass spectrometry. Colorectal cancer was epigenotyped by unsupervised two-way hierarchical clustering method. Results: Among 1,311 candidate silencing genes, 44 new markers were selected and underwent quantitative methylation analysis in colorectal cancer samples together with 16 previously reported markers. Colorectal cancer was clustered into high-, intermediate-, and low-methylation epigenotypes. Methylation markers were clustered into two major groups: group 1 showing methylation in high-methylation epigenotype, and group 2 showing methylation in high- and intermediate-methylation epigenotypes. A two-step marker panel deciding epigenotypes was developed with 95% accuracy: the 1st panel consisting of three group-1 markers (CACNA1G, LOX, SLC30A10) to extract high-methylation epigenotype, and the 2nd panel consisting of four group-2 markers (ELMO1, FBN2, THBD, HAND1) and SLC30A10 again to divide the remains into intermediate- and low-methylation epigenotypes. The high-methylation epigenotype correlated significantly with MSI-high and BRAF-mutation(+) in concordance with reported CIMP. Intermediate-epigenotype significantly correlated with KRAS-mutation(+). KRAS-mutation(+) colorectal cancer with intermediate-methylation epigenotype showed significantly worse prognosis. Conclusions: Three methylation epigenotypes exist in colorectal cancer, and suitable classification markers have been developed. Intermediate-methylation epigenotype with KRAS-mutation(+) correlated with worse prognosis. Clin Cancer Res; 16(1); 21–33

Adjuvant chemotherapy of S-1 versus gemcitabine for resected pancreatic cancer: a phase 3, open-label, randomised, non-inferiority trial (JASPAC 01)

BACKGROUND Although adjuvant chemotherapy with gemcitabine is standard care for resected pancreatic cancer, S-1 has shown non-inferiority to gemcitabine for advanced disease. We aimed to investigate the non-inferiority of S-1 to gemcitabine as adjuvant chemotherapy for pancreatic cancer in terms of overall survival. METHODS We did a randomised, open-label, multicentre, non-inferiority phase 3 trial undertaken at 33 hospitals in Japan. Patients who had histologically proven invasive ductal carcinoma of the pancreas, pathologically documented stage I-III, and no local residual or microscopic residual tumour, and were aged 20 years or older were eligible. Patients with resected pancreatic cancer were randomly assigned (in a 1:1 ratio) to receive gemcitabine (1000 mg/m(2), intravenously administered on days 1, 8, and 15, every 4 weeks [one cycle], for up to six cycles) or S-1 (40 mg, 50 mg, or 60 mg according to body-surface area, orally administered twice a day for 28 days followed by a 14 day rest, every 6 weeks [one cycle], for up to four cycles) at the data centre by a modified minimisation method, balancing residual tumour status, nodal status, and institutions. The primary outcome was overall survival in the two treatment groups, assessed in the per-protocol population, excluding ineligible patients and those not receiving the allocated treatment. The protocol prespecified that the superiority of S-1 with respect to overall survival was also to be assessed in the per-protocol population by a log-rank test, if the non-inferiority of S-1 was verified. We estimated overall and relapse-free survival using the Kaplan-Meier methods, and assessed non-inferiority of S-1 to gemcitabine using the Cox proportional hazard model. The expected hazard ratio (HR) for mortality was 0.87 with a non-inferiority margin of 1.25 (power 80%; one-sided type I error 2.5%). This trial is registered at UMIN CTR (UMIN000000655). FINDINGS 385 patients were randomly assigned to treatment between April 11, 2007, and June 29, 2010 (193 to the gemcitabine group and 192 to the S-1 group). Of these, three were exlcuded because of ineligibility and five did not receive chemotherapy. The per-protocol population therefore consisted of 190 patients in the gemcitabine group and 187 patients in the S-1 group. On Sept 15, 2012, following the recommendation from the independent data and safety monitoring committee, this study was discontinued because the prespecified criteria for early discontinuation were met at the interim analysis for efficacy, when all the protocol treatments had been finished. Analysis with the follow-up data on Jan 15, 2016, showed HR of mortality was 0.57 (95% CI 0.44-0.72, pnon-inferiority<0.0001, p<0.0001 for superiority), associated with 5-year overall survival of 24.4% (18.6-30.8) in the gemcitabine group and 44.1% (36.9-51.1) in the S-1 group. Grade 3 or 4 leucopenia, neutropenia, aspartate aminotransferase, and alanine aminotransferase were observed more frequently in the gemcitabine group, whereas stomatitis and diarrhoea were more frequently experienced in the S-1 group. INTERPRETATION Adjuvant chemotherapy with S-1 can be a new standard care for resected pancreatic cancer in Japanese patients. These results should be assessed in non-Asian patients. FUNDING Pharma Valley Center, Shizuoka Industrial Foundation, Taiho Pharmaceutical.

Intraoperative irradiation after surgery for locally recurrent rectal cancer

PURPOSE: This study retrospectively evaluated the effects of intraoperative electron beam irradiation on patients with locally recurrent (pelvic) rectal cancer. METHODS: From November 1, 1975, to December 31, 1997, 51 patients underwent surgery for locally recurrent rectal or rectosigmoid cancer, and 27 patients received intraoperative electron beam irradiation. The intraoperative electron beam irradiation dose was 15 to 30 Gy. Kaplan-Meier survival estimates at three and five years were analyzed for the 47 patients who recovered postoperatively. RESULTS: Statistically significant factors related to survival included intraoperative electron beam irradiationvs. no intraoperative electron beam irradiation (P=0.0007), amount of residual tumor (slightvs. gross;P=0.0022), and symptom status (P=0.0024). Factors not associated with survival included distant metastases at reoperation, type of surgery for the recurrent tumor, external beam irradiation, pathologic grade, age, and gender. Surgical resection without intraoperative electron beam irradiation resulted in three-year and five-year survival rates of 5 and 0 percent, respectively. For patients who received intraoperative electron beam irradiation, the three-year survival rate was 43 percent and five-year survival rate was 21 percent. Intraoperative electron beam irradiation was a statistically significant factor related to survival in patients with and without distant metastasis (P=0.04 andP=0.0035, respectively), with slight residual tumor (P=0.0003), or with palliative surgery (P=0.0276). CONCLUSION: The trends seen in resection with intraoperative electron beam irradiation are encouraging with regard to improvements in survival as compared with studies not using intraoperative electron beam irradiation treatment.

Distinct chromosomal bias of gene expression signatures in the progression of hepatocellular carcinoma

To identify the chromosomal aberrations associated with the progression of liver cancer, we applied expression imbalance map analysis to gene expression data from 31 hepatocellular carcinomas and 19 noncancerous tissues. Expression imbalance map analysis, which detects mRNA expression imbalance correlated with chromosomal regions, showed that expression gains of 1q21-23 (74%), 8q13-21 (48%), 12q23-24 (41%), 17q12-21(48%), 17q25 (25%), and 20q11 (22%) and losses of 4q13 (48%), 8p12-21 (32%), 13q14 (32%), and 17p13 (29%) were significantly associated with hepatocellular carcinoma. Most regions with altered expression identified by expression imbalance map were also identified in previous reports using comparative genomic hybridization. We demonstrated chromosomal copy number gain in 1q21-23 and loss in 17p13 by genomic quantitative PCR, suggesting that gene expression profiles reflect chromosomal alterations. Furthermore, expression imbalance map analysis revealed that more poorly differentiated hepatocellular carcinoma contain more chromosomal alterations, which are accumulated in a stepwise manner in the course of hepatocellular carcinoma progression: expression imbalance of 1q, 8p, 8q, and 17p occur as early events in hepatocarcinogenesis, and 12q, 17q25 and 20q occur as later events. In particular, expression gain of 17q12-21 and loss of 4q were seen to accumulate constantly through the dedifferentiation process. Our data suggest that gene expression profiles are subject to chromosomal bias and that expression imbalance map can correlate gene expression to gene loci with high resolution and sensitivity.

Identification of chromosomal aberrations of metastatic potential in colorectal carcinoma.

In colorectal cancer (CRC) care, treatment decisions depend on the efforts to estimate the metastatic potential of tumors. The liver is one of the most common metastatic sites of CRC and the prognosis of CRC patients often reflects metastases to distant sites. To identify chromosomal aberrations associated with liver metastasis, we performed allelic copy number analysis for CRC with or without synchronous liver metastasis using genotyping arrays. By allelic copy number analysis of CRC samples, we observed common aberrations in 14 chromosomal arms in two groups, that is, gains on 7p22.3‐p11.2, 8q22.3‐q24.3, 13q12.12‐q34, and 20q11.22‐q13.33 and loss of heterozygosity (LOH) on 4q12‐q35.1, 5q11.2‐q35.3, 8p23.3‐p12, 15q11.2‐q26.3, 17p13.3‐p11.2, 17q11.2‐q25.1, 18p11.32‐p11.21, 18q11.2‐q23, 20p13‐p12.1, and 22q11.1‐q13.32. We found that gains on 20p13‐p12.1 and 20q11.21‐q13.33 and LOH on 6q14.1‐q25.1 were more frequent in CRC with liver metastasis. We also compared chromosomal aberrations in primary CRC lesions with those of the corresponding liver metastasis and found that the allelic genome imbalance status of a metastatic lesion is similar to that of the primary cancer, which suggests that chromosomal aberrations are largely maintained on hematogenous spread. Intriguingly, several chromosomal aberrations in CRC were found in the primary cancer but not in the corresponding liver metastasis, thus suggesting heterogeneity of cancer cells within solid tumors or the presence of events uniquely developed in primary tumors. Consequently, CRC with and without liver metastasis harbor similar chromosomal aberrations, and chromosomal aberration at 6q, 20p, and 20q may be involved in the process of liver metastasis of CRC.

Clinicopathological characteristics and prognostic impact of colorectal cancers with NRAS mutations

At present, molecular markers of colorectal cancer (CRC), including KRAS, NRAS and BRAF mutations, and the microsatellite status are evaluated for the development of personalized treatments. However, clinicopathological and molecular characteristics and the prognostic role of NRAS mutations remain unclear. In the present study, a total of 1,304 consecutive stage 0-IV CRC tumor samples were analyzed for KRAS (exon 2, 3 and 4), NRAS (exon 2 and 3) and BRAF (exon 15) mutations. Multivariate analysis was performed to assess the prognostic impact of NRAS mutations. KRAS, NRAS and BRAF mutations were identified in 553 (42.4%), 35 (2.7%), and 59 (4.5%) of 1,304 CRC cases, respectively. Tumors with NRAS mutations were more frequently located in the distal colorectum compared with those with KRAS or BRAF mutations. Multivariate analysis indicated that KRAS and BRAF mutations were found to be associated with poor prognosis [hazard ratio (HR)=1.44, 95% confidence interval (CI), 1.18-1.76 and HR=2.09; 95% CI, 1.33-3.28, respectively], whereas NRAS mutations were associated with a trend toward favorable prognosis (HR=0.53; 95% CI, 0.27-1.03). Characteristics and prognosis of CRC with NRAS mutations are different from those with KRAS or BRAF mutations.

Indicators for surgical resection and intraoperative radiation therapy for pelvic recurrence of colorectal cancer.

AbstractPURPOSE: We retrospectively analyzed prognostic factors for surgical resection and intraoperative radiation therapy to identify indicators for this treatment strategy. METHODS: Thirty-nine consecutive patients with locally recurrent colorectal cancer who underwent surgical resection with intraoperative radiation therapy from January 1, 1987, to June 30, 1999, were analyzed. The mean electron energy was 10.5 MeV and the mean intraoperative radiation dose was 22.6 Gy. Kaplan-Meier survival estimates were obtained for the 37 patients who recovered postoperatively. Prognostic factors were analyzed univariately by log-rank test and multivariately by Cox’s proportional hazards model. RESULTS: Three-year cumulative survival was 44 percent (standard error = 11) for 26 patients free of unresectable distant metastasis who underwent surgical resection and intraoperative radiation therapy for pelvic recurrence of colorectal cancer, but none of the 11 patients with unresectable distant metastasis survived 3 years. Preoperative prognostic factors which were significant on univariate and multivariate analysis were unresectable distant metastasis (P = 0.001) and elevated preoperative serum CA 19–9 (P = 0.02). Patients with synchronous resection of local recurrence and distant metastasis had a significant survival advantage over those without resection of metastases (P = 0.02). Univariate analysis in a subgroup of 26 patients without unresectable distant metastasis revealed pain (P = 0.0003) to be a useful preoperative prognostic indicator, whereas tumor fixation (P = 0.01) and amount of residual tumor after surgical resection (P = 0.01) were significant intraoperative and postoperative factors, respectively. Fluorouracil-based postoperative systemic chemotherapy produced a significant survival benefit (P = 0.04). CONCLUSIONS: Patients with unresectable distant metastasis are not suitable candidates for surgical resection and intraoperative radiation therapy, whereas those with resectable metastasis are potential candidates. Intraoperative radiation therapy may be less useful for patients with pain, elevated preoperative CA19–9, fixed tumors, or gross residual tumor after surgical resection. Multimodal treatment strategies combining preoperative and/or postoperative external beam radiation therapy and intraoperative radiation therapy with fluorouracil-based systemic chemotherapy are recommended for patients with these indicators.

Expression of thymidylate synthase and thymidine phosphorylase in recurrence and survival rates of advanced gastric cancer

Abstract:Background. The immunohistochemical expression of thymidylate synthase (TS) and thymidine phosphorylase (TP) was examined in a comparative study of the recurrence rates and prognoses of patients with advanced gastric cancer at the same stage.Methods. We examined the resected specimens of 67 patients with stage IIIB gastric cancer (pT3, pN2, M0) under 70 years of age who had undergone curative gastrectomy followed by adjuvant chemotherapy with 5-fluoropyrimidines. Paraffin sections of the resected specimens were stained with human anti-TS polyclonal and anti-TP monoclonal antibodies by the avidin-biotin-peroxidase complex (ABC) method.Results. The overall expression of TS and TP was 45.4% and 43.4%, respectively. The postoperative survival curve for the TS-positive group was significantly depressed compared with that for the TS-negative group (P = 0.0480). The survival curves for TP-positive and TP-negative groups did not show any difference. In regard to the combination of TS and TP expression, the best survival curve was obtained for the TS(−)/TP(+) group, followed by those for the TS(−)/TP(−), TS(+)/TP(−), and TS(+)/TP(+) groups in descending order. With regard to the recurrence site, there was no significant difference in peritoneal recurrence in relation to positivity for TS or TP. Lymph node recurrence, however, was significantly higher in the TS-positive and TP-positive groups, with P-values being 0.0466 and 0.0058, respectively, versus the corresponding negative groups. The incidence of hepatic recurrence was higher in the TP-positive group than in the TP-negative group (P = 0.0910). As for the total doses of 5-fluoropyrimidines given, more favorable survival curves were obtained for the high dose of negative TS and TP groups, but no significant differences were observed in their positivities.Conclusion. The expressions of TS and TP showed different characteristics in overall survival and recurrence rate or site. They should be used for predicting prognosis in comprehension on their properties.

Surgical management for a malignant bowel obstruction with recurrent gastrointestinal carcinoma

A malignant bowel obstruction (MBO) is a common clinical complication in patients with recurrent gastrointestinal carcinoma, which has a poor prognosis and a limited life expectancy. This study considered the effectiveness of surgical management for MBO.