Takashi Mine

Optimum Treatment Strategy for Superficial Esophageal Cancer: Endoscopic Mucosal Resection versus Radical Esophagectomy

This study was designed to determine the optimum treatment for a superficial esophageal cancer involving the mucosal or submucosal layer of the esophagus. The subjects were 150 patients with a superficial esophageal cancer who underwent endoscopic mucosal resection (EMR) or esophagectomy in Kurume University Hospital from 1981 to 1997. The mortality and morbidity rates, survival rate, and recurrence rate were retrospectively compared for (1) 35 patients who underwent EMR and 37 patients who underwent esophagectomy for a mucosal esophageal cancer and (2) 45 patients who underwent extended radical esophagectomy and 33 patients who underwent less radical esophagectomy for a submucosal esophageal cancer. Among the 72 patients with a mucosal cancer, lymph node metastasis/recurrence was observed in only one (1%); whereas of 78 patients with a submucosal cancer it was observed in 30 (38%). Among patients with a mucosal cancer the mortality and morbidity rates after EMR were lower than for those after esophagectomy. The survival rate after EMR was the same as that after esophagectomy. No recurrence was observed after either treatment modality. Among the patients with a submucosal cancer, the survival rate was higher and the recurrence rate lower after extended radical esophagectomy; than after less radical esophagectomy; the mortality and morbidity rates after extended radical esophagectomy were the same as those after less radical esophagectomy. Multivariate analysis demonstrated that the treatment modality (EMR versus esophagectomy) did not influence the survival of patients with a mucosal esophageal cancer, whereas it strongly influenced the survival of patients with a submucosal esophageal cancer. We concluded that EMR was the mainstay of treatment for a mucosal esophageal cancer, and extended radical esophagectomy was the mainstay of treatment for a submucosal esophageal cancer.

Immunologic Evaluation of Personalized Peptide Vaccination for Patients with Advanced Malignant Glioma

Purpose: The primary goal of this phase I study was to assess the safety and immunologic responses of personalized peptide vaccination for patients with advanced malignant glioma. Experimental Design: Twenty-five patients with advanced malignant glioma (8 grade 3 and 17 grade 4 gliomas) were evaluated in a phase I clinical study of a personalized peptide vaccination. For personalized peptide vaccination, prevaccination peripheral blood mononuclear cells and plasma were provided to examine cellular and humoral responses to 25 or 23 peptides in HLA-A24+ or HLA-A2+ patients, respectively; then, only the reactive peptides (maximum of four) were used for in vivo administration. Results: The protocols were well tolerated with local redness and swelling at the injection site in most cases. Twenty-one patients received more than six vaccinations and were evaluated for both immunologic and clinical responses. Increases in cellular or humoral responses specific to at least one of the vaccinated peptides were observed in the postvaccination (sixth) samples from 14 or 11 of 21 patients, respectively. More importantly, significant levels of peptide-specific IgG were detected in the postvaccination tumor cavity or spinal fluid of all of the tested patients who showed favorable clinical responses. Clinical responses were 5 partial responses, 8 cases of stable disease, and 8 cases of progressive disease. The median overall survival for patients with recurrent glioblastoma multiforme in this study (n = 17) was 622 days. Conclusions: Personalized peptide vaccinations were recommended for the further clinical study to malignant glioma patients.

Humoral Responses to Peptides Correlate with Overall Survival in Advanced Cancer Patients Vaccinated with Peptides Based on Pre-existing, Peptide-Specific Cellular Responses

Purpose: The aim of this study is to find a laboratory marker for overall survival in advanced cancer patients who were vaccinated with peptides based on pre-existing, peptide-specific CTL precursors in the circulation. Experimental Design: A group of 113 patients with advanced cancer (28 colorectal, 22 prostate, 15 lung, 14 gastric, and 34 other cancers) was enrolled in a Phase I clinical study of peptide vaccination in which peptide-specific CTL precursors of prevaccination peripheral blood mononuclear cells were measured, followed by vaccination with these peptides (maximum of four). For cellular responses, pre and postvaccination (sixth) peripheral blood mononuclear cells were provided for measurement of both peptide-specific CTL precursors by IFN-γ release assay and tumor reactivity by 51Cr release assay. Delayed type hypersensitivity was also measured. For humoral response, pre and postvaccination (sixth) sera were provided for measurement of peptide-reactive IgG by an ELISA. Results: The median survival time and 1-year survival rate of the total cases were 346 ± 64.9 days and 44.6%, respectively, and those of patients vaccinated more than six times (n = 91) were 409 ± 15 days and 54.4%, respectively. In these 91 patients, the overall survival of patients whose sera showed increased levels of peptide-reactive IgG (n = 60) was significantly more prolonged (P = 0.0003) than that of patients whose sera did not (n = 31), whereas none of cellular responses correlated with overall survival. Conclusions: Peptide-specific IgG in postvaccination sera could be a suitable laboratory maker for the prediction of prolonged survival in advanced cancer patients vaccinated with peptides based on pre-existing CTL precursors.

Optimal Lymphadenectomy for Squamous Cell Carcinoma in the Thoracic Esophagus: Comparing the Short- and Long-term Outcome among the Four Types of Lymphadenectomy

Controversy continues over the optimal extent of lymphadenectomy (regional versus three-field) for a potentially resectable squamous cell carcinoma in the thoracic esophagus. In the Consensus Conference of the International Society for Diseases of the Esophagus (ISDE), held in Munich in 1994, the types of lymphadenectomy were classified as standard, extended, total, or three-field lymphadenectomy. The objective of the present study was to determine the optimal procedure among these four types of lymphadenectomy. The mortality and morbidity rates, postoperative course, and survival rates were compared among 302 patients who underwent curative (R0) transthoracic esophagectomy with one of these four types of lymphadenectomy at Kurume University Hospital, Fukuoka, Japan, from 1986 to 1998. Three-field lymphadenectomy resulted in better survival than any other type of lymphadenectomy for patients with positive lymph node metastasis from a cancer in the upper or middle thoracic esophagus. A postoperative complication, such as recurrent laryngeal nerve paralysis, anastomotic leakage, and tracheal ischemic lesion, was significantly more common after three-field lymphadenectomy. However, the mortality rate was the same among the four procedures. Three-field lymphadenectomy was optimal for an upper or middle thoracic esophageal cancer with metastasis in the lymph node(s) based on improved long-term survival, whereas there was not a large difference in short-term and long-term outcomes after the four types of lymphadenectomy for a lower thoracic esophageal cancer.

Immunological evaluation of peptide vaccination for patients with gastric cancer based on pre‐existing cellular response to peptide

There is no standard treatment modality for advanced gastric cancer (GC) at the present time. To develop a new treatment modality, we investigated the immunological responses of advanced GC patients (n=13, 9 non‐scirrhous and 4 scirrhous types) vaccinated with peptides to a regimen under which pre‐vaccination peripheral blood mononuclear cells (PBMCs) were screened for their reactivity in vitro to each of 14 peptides on HLA‐A24 or 16 peptides on ‐A2 allele, then only the reactive peptides (maximum: 4) were administered in vivo. This regimen was generally well tolerated, although grade I levels of fever and local skin reactions were observed in several patients. Delayed‐type hypersensitivity (DTH) to the vaccinated peptides was observed in 4 patients. Increased cellular and humoral immune responses to the vaccinated peptides were observed in post‐vaccination PBMCs from 4 of 8 patients and in post‐vaccination sera of 8 of 10 patients tested, respectively. Prolonged survival was observed in patients showing cellular and humoral immune responses to the vaccinated peptides in the post‐vaccination samples, including all 4 patients with the scirrhous type. These results encourage further development of peptide‐based immunotherapy for GC patients.

Immunological evaluation of CTL precursor-oriented vaccines for advanced lung cancer patients

Recent clinical trials of peptide vaccine for cancer patients have rarely resulted in tumor regression. One of the reasons for this failure could be an insufficient induction of anti‐tumor responses in these regimens, in which peptide‐specific memory cytotoxic T lymphocytes (CTLs) were not measured prior to vaccination. We investigated in this study whether pre‐vaccination measurement of peptide‐specific CTLs can provide any advantages in lung cancer patients receiving peptide vaccination with regard to safety and immunological responses. Ten patients with advanced lung cancer received vaccination with peptides under a regimen of CTL precursor‐oriented vaccination, in which pre‐vaccination peripheral blood mononuclear cells (PBMCs) were at first screened for reactivity in vitro to each of 14 peptides, followed by in vivo administration of only the reactive peptides. Profiles of the vaccinated peptides varied markedly among the 10 patients. This regimen was generally well‐tolerated, although local skin reactions, diarrhea, and colitis were observed in 8, 2, and 1 patient, respectively. Increased CTL responses against the immunized peptides and tumor cells were observed in the post‐vaccination PBMCs from 4 of 8 and 3 of 10 patients tested, respectively. Peptide‐specific IgG became detectable in post‐vaccination sera in 4 of 10 patients tested, and these 4 patients had a long progression‐free survival. Furthermore, the median survival time of 9 patients with non‐small cell lung cancer was 668.0±164.2 days. These results encourage further development of CTL precursor‐oriented peptide vaccination for lung cancer patients.

Recent Advances in Cancer Vaccines: An Overview

The field of cancer vaccines is currently in an active state of clinical investigations. Human papilloma virus vaccine has been approved as a prophylactic cancer vaccine, while Oncophage (heat shock protein-peptide complex) was recently approved in Russia for a certain stage of kidney cancer, although to date none has been approved in Japan or the USA. We reviewed recent clinical trials of several different types of cancer vaccines, mainly by using PubMed from 2005 to 2008. There have been slow but substantial advances in peptide vaccines and dendritic cell-based vaccines with regard to both clinical responses and immunological markers. A personalized approach to boost immune responses, addition of chemotherapy to overcome robust cancers and changing of endpoints from tumor reduction to overall survival seem to be the three key elements for the development of therapeutic cancer vaccines.

Immunological evaluation of personalized peptide vaccination with gemcitabine for pancreatic cancer

The aim of the present study was to investigate the safety and immune responses of personalized peptide vaccination when administered with gemcitabine (GEM) in advanced pancreatic cancer (APC) patients. Thirteen patients with APC were enrolled. Pre‐vaccination with peripheral blood mononuclear cells and plasma was carried out to examine cellular and humoral responses to 25 or 23 peptides in human leukocyte antigen A24++ or A2+++ patients, respectively. Only the reactive peptides (maximum of four) were then administered weekly at three different dose settings: 1, 2 and 3 mg of peptide. GEM was administered at 1000 mg/m2 per week for 3 weeks, followed by 1 week of rest. The combination therapy was well tolerated. Grade 3 toxicities were: anemia (three patients), neutropenia (two patients) and thrombocytopenia (two patients). Of these 13 patients, 11 (85%) showed clinical responses, such as reduction in tumor size and/or level of tumor markers. Augmentation of peptide‐specific cytotoxic T lymphocyte activity against pancreatic cancer cells was observed at each dose level, whereas the increment of peptide‐specific IgG antibodies was dependent on peptide dose. GEM did not inhibit the immune responses induced by personalized peptide vaccinations, and this new type of immunochemotherapy combination is recommended for further clinical study in APC patients. (Cancer Sci 2007; 98: 605–611)

Peptide Vaccination for Patients With Melanoma and Other Types of Cancer Based on Pre-existing Peptide-Specific Cytotoxic T-Lymphocyte Precursors in the Periphery

Identification of antigenic peptides expressed on cancer cells enables us to treat cancer patients with peptide-based immunotherapy. Although optimal protocols for peptide-based vaccines have not yet been elucidated, boosting the immune system could be a better approach than priming the immune system to elicit prompt and potent peptide-specific T-cell responses in cancer patients. With this possibility in mind, the authors undertook a clinical trial in which cancer patients were vaccinated with peptides (maximum 4) after confirmation of pre-existing peptide-specific cytotoxic T-lymphocyte (CTL) precursors in the periphery. Fourteen patients (seven with melanoma and seven with other types of cancer) positive for either HLA-A24 or HLA-A2 were enrolled in this study. Fourteen and 16 peptides were used to screen for HLA-A24+ and HLA-A2+ patients, respectively. The vaccination was well tolerated, and the only adverse effects were local pain and fever. Kinetic analysis revealed that peptide-reactive CTLs increased after peptide vaccination in 7 of 14 patients. Immunoglobulin G (IgG) reactive to the administered peptides was detected in 2 patients before vaccination, although it became detectable in 8 of the other 12 patients after the peptide vaccination. Stable disease for more than 6 months was observed in five patients (one with melanoma and four with other types of cancer); all of these patients showed increased levels of peptide-specific IgG. These results indicate that peptide vaccination of patients showing evidence of pre-existing peptide-specific CTL precursors can be applied in further clinical trials aimed at the treatment of melanoma and other types of cancer.

Breast cancer cells expressing stem cell markers CD44 + CD24 lo are eliminated by Numb-1 peptide-activated T cells

Cancer stem cells (CSC) are resistant to chemo- and radiotherapy. To eliminate cells with phenotypic markers of CSC-like we characterized: (1) expression of CD44, CD24, CD133 and MIC-A/B (NKG2 receptors) in breast (MCF7) and ovarian (SK-OV-3) cells resistant to gemcitabine (GEM), paclitaxel (PTX) and 5-fluorouracil (5-FU) and (2) their elimination by Numb- and Notch-peptide activated CTL. The number of cells in all populations with the luminal CSC phenotype [epithelial specific antigen+ (ESA) CD44hi CD24lo, CD44hi CD133+, and CD133+ CD24lo] increased in drug-resistant MCF7 and SK-OV-3 cells. Similarly, the number of cells with expressed MIC-A/B increased 4 times in drug-resistant tumor cells compared with drug-sensitive cells. GEMRes MCF7 cells had lower levels of the Notch-1-extracellular domain (NECD) and Notch trans-membrane intracellular domain (TMIC) than GEMSens MCF7. The levels of Numb, and Numb-L-[P]-Ser265 were similar in GEMRes and GEMSens MCF7 cells. Only the levels of Numb-L (long)-Ser295 decreased slightly. This finding suggests that Notch-1 cleavage to TMIC is inhibited in GEMRes MCF7 cells. PBMC activated by natural immunogenic peptides Notch-1 (2112–2120) and Numb-1 (87–95) eliminated NICDpositive, CD24hi CD24lo MCF7 cells. It is likely that the immunogenic Numb-1 peptide in MCF7 cells originated from Numb, [P]-lated by an unknown kinase, because staurosporine but not wortmannin and MAPK-inhibitors decreased peptide presentation. Numb and Notch are antagonistic proteins which degrade each other to stop and activate cell proliferation, respectively. Their peptides are presented alternatively. Targeting both antagonistic proteins should be useful to prevent metastases in patients whose tumors are resistant to conventional treatments.