Biomedical subjects

Junji Yamamoto

Publications and source records attributed to Junji Yamamoto.

50 records · Page 3Linked to original sources

PubMed2003

Surgical resection of liver metastases of gastric cancer: an analysis of a 17-year experience with 22 patients.

BACKGROUND: The justification for surgical resection of liver metastases from gastric cancer remains controversial. METHODS: Twenty-two patients who underwent 26 hepatectomies for liver metastases of gastric cancer between 1985 and 2001 were analyzed. Fifteen clinicopathologic factors were evaluated with univariate and multivariate analyses for survival after hepatic resection. RESULTS: The overall 1-year, 3-year, and 5-year survival rates after hepatectomy for gastric metastases were 73%, 38%, and 38%, respectively. Five patients survived for more than 3 years without recurrence, 3 of whom had synchronous metastases resected at the time of gastrectomy. The best results after surgical resection for liver metastases of gastric cancer were obtained with solitary metastases less than 5 cm in size. The number of liver metastases (solitary or multiple) was the only significant prognostic factor according to both univariate and multivariate analyses. CONCLUSION: Surgical resection for liver metastases of gastric cancer may be beneficial for patients with a solitary metastasis, whether it is synchronous or metachronous.

Aged↗

PubMed2003

Combined hepatocellular and cholangiocarcinoma: a clinicopathologic study of 26 resected cases.

BACKGROUND: Combined hepatocellular and cholangiocarcinoma (cHCC-CC) is an uncommon subtype of primary liver cancer, the clinicopathological features of which have rarely been reported in detail. The aim of this study was to clarify the characteristics of cHCC-CC in comparison with hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). METHODS: The clinicopathological features of 26 cHCC-CC patients, who were surgically treated, were reviewed by comparing them with the features of patients suffering from ordinary hepatocellular carcinoma (HCC) and cholangiocarcinoma (CC). RESULTS: The cHCC-CC patients showed greater similarity with HCC patients than with CC patients with regard to male/female ratio, status of hepatitis viral infection, serum alpha-fetoprotein (AFP) level, and non-tumor liver histology. The disease stage of the cHCC-CC patients was more advanced than that of either the HCC or CC patients. The cHCC-CC tumors were significantly more invasive to the portal vein than the HCC tumors and were comparable to the CC tumors. The overall 3-, 5-, and 10-year survival rates and the median survival times (95% confidence interval) were 34.6%, 23.1%, 11.5% and 1.8 (0.7-3.0) years for cHCC-CC patients, 86.7%, 66.2%, 46.8% and 4.6 (4.3-5.0) years for HCC patients, and 68.5%, 32.3%, 23.9% and 1.9 (1.1-2.7) years for CC patients, respectively. Survival of patients with cHCC-CC was significantly poorer than that of HCC or CC patients. Among the 26 patients, six survived for >5 years. CONCLUSIONS: In most cases, cHCC-CC seems to be a variant of ordinary HCC with cholangiocellular features, rather than a true intermediate disease entity between HCC and CC. The surgical approach is recommended for selected patients with cHCC-CC.

Adolescent↗

PubMed2003

Segmental resection of the third portion of the duodenum for a gastrointestinal stromal tumor: a case report.

We describe a case in which segmental resection of the third portion of the duodenum was performed for a gastrointestinal stromal tumor (GIST). A 31-year-old woman was found to have a 3.5 cm hypovascular tumor at the posterior inferior aspect of the pancreatic head. Preoperative duodenal biopsy revealed that the tumor was positive for c-kit and vimentin, and was diagnosed as a duodenal GIST. Segmental resection of the third portion of the duodenum with papilloplasty and duodenojejunostomy was carried out and there were no postoperative complications. Pancreatoduodenectomy is not always necessary in the treatment of a duodenal GIST. This duodenectomy procedure can serve as a less extensive resection for a duodenal GIST located in the third portion of the duodenum.

Adenocarcinoma↗

PubMed2003

Therapeutic results for hepatic metastasis of colorectal cancer with special reference to effectiveness of hepatectomy: analysis of prognostic factors for 763 cases recorded at 18 institutions.

PURPOSE: Factors affecting treatment prognosis and therapeutic results for hepatic metastasis of colorectal cancer were investigated. METHODS: Therapeutic results, especially of hepatectomy, were investigated for hepatic metastasis of colorectal cancer in 763 patients (585 underwent hepatectomy) treated between 1992 and 1996 at 18 institutions that participated in the "Study for establishing treatments for hepatic and pulmonary metastasis of colorectal cancer" sponsored by a Grant-in-Aid (10-11) for Cancer Research from the Ministry of Health, Welfare and Labor of Japan. RESULTS: The five-year survival rate for those treated by hepatectomy was significantly higher (32.9 percent) than for those not undergoing hepatectomy (3.4 percent). After hepatectomy for hepatic metastasis, the most prevalent form of recurrence was in the remnant liver (41.4 percent), followed by recurrence of pulmonary metastasis (19.2 percent), and other (7.2 percent). Factors of the primary tumor adversely affecting prognosis after hepatectomy for hepatic metastasis included poorly differentiated adenocarcinoma or mucinous carcinoma, depth of invasion of si/ai, lymph-node metastasis of Stage n3 and n4 by the Japanese classification of colorectal carcinoma, number of metastatic lymph nodes of more than four, and Dukes Stage D. Factors at the time of hepatectomy adversely affecting prognosis after surgery for hepatic metastasis included residual tumor, extrahepatic metastasis, hepatic metastasis of degree H3 stipulated by the Japanese classification of colorectal carcinoma, number of metastases of four or more, pathology of hepatic metastasis of poorly differentiated adenocarcinoma, resection margin of <10 mm, and carcinoembryonic antigen value higher than normal preoperative and one month postoperative. CONCLUSIONS: Among therapies for hepatic metastasis of colorectal cancer, the present study clearly revealed that hepatectomy is the treatment of choice whenever feasible. Postoperative recurrence often is localized in the remnant liver, or there may be a systemic recurrence of pulmonary metastasis. Thus, methods of prevention will be a future theme.

Colorectal Neoplasms↗

PubMed2003

Micro-Raman densimeter for CO2 inclusions in mantle-derived minerals.

We investigated the applicability of Raman microprobe spectroscopy for determining the density of CO2 in fluid inclusions in minerals of mantle-derived xenolith samples. A separation (delta) between two Raman bands of CO2 due to Fermi resonance can be a reliable densimeter for CO2 fluid. The relationship between the density of CO2 (g/cm3) and delta (cm-1) can be expressed as: d = -0.03238697 delta 3 + 10.08428 delta 2 - 1046.189 delta + 36163.67. This equation was obtained from the Raman data on CO2 fluid with densities from 0.1 to 1.21 g/cm3, including super critical fluids at 58-59 degrees C. The delta value was constant with increasing temperature from room temperature to 200 degrees C. This indicates that the Raman densimeter is not affected by a possible rise in temperature, an artifact induced by the high flux of the incident laser. The minimum size of measurable inclusions is 1 micron, and the precision in the determination of delta is 0.1 cm-1, corresponding to 0.02 g/cm3 for inclusions of 1 micron in size. The precision can be better for larger inclusions. The micro-Raman densimeter can determine the density of CO2 fluid inclusions over a wide range. In particular, densities of gas and mixtures of gas and liquid phases, which cannot be measured by microthermometry, can be determined.

Calibration↗

PubMed2002

Satellite lesions in patients with small hepatocellular carcinoma with reference to clinicopathologic features.

BACKGROUND: It is not rare to find satellite lesions in patients with small hepatocellular carcinoma (HCC). The purpose of this study was to elucidate the factors associated with satellite lesions in these patients. METHODS: We investigated the prevalence of satellite lesions, the relationship of clinicopathologic factors to satellite lesions, and the distance from the main tumor to the satellite lesion in 149 patients. Patients, who had a solitary HCC of 3.0 cm or less in diameter but no satellite lesions on preoperative imaging procedures, underwent potentially curative resection. The main tumors were macroscopically classified into four groups: early HCC, a vaguely nodular type showing preservation of the preexisting liver structure; single nodular type; single nodular type with extranodular growth; and confluent multinodular type. RESULTS: Of 149 resected specimens, 28 (19%) showed satellite lesions. Of the clinicopathologic factors investigated, the macroscopic type and tumor differentiation were significantly associated with the prevalence of satellite lesions. Both the single nodular type with extranodular growth and the confluent multinodular type showed satellite lesions more frequently than the early HCC and the single nodular type. A significantly higher prevalence of satellite lesions was observed in poorly differentiated HCC than in well and moderately differentiated HCC. The satellite lesions were located 0.5 cm or less from the main tumor in 8 (33%) specimens, 0.6-1.0 cm in 12 (50%), and 1.1-2.0 cm in 4 (17%). No identifiable factors were significantly related to the distance from the main tumor to the satellite lesion. However, all satellite lesions located more than 1.0 cm from the main tumor coexisted with poorly differentiated HCC, which were the single nodular type with extranodular growth or the confluent multinodular type. CONCLUSION: In the single nodular type with extranodular growth, confluent multinodular type, and poorly differentiated HCC, extensive treatment achieving a large safety margin and/or frequent posttreatment follow-up examinations may be needed because of the high prevalence of satellite lesions.

Adult↗

PubMed2002

Genetic and histological assessment of surgical margins in resected liver metastases from colorectal carcinoma: minimum surgical margins for successful resection.

HYPOTHESIS: There have been few reports on the minimum surgical margins (SMs) required for successful liver resection in patients with colorectal metastases. This minimum requirement may be narrower than the previously recommended margin of 10 mm. OBJECTIVES: To identify the minimum margins by assessing the presence of micrometastases around the tumor using genetic and histological techniques, and to investigate whether SMs are associated with patterns of tumor recurrence or patient survival. DESIGN: Prospective and retrospective studies. SETTING: Tertiary referral cancer center. PATIENTS AND METHODS: Fifty-eight patients who underwent 62 liver resections for hepatic metastasis from colorectal cancer between December 1, 1996, and November 30, 2000, were included in the study. Tissue samples taken from the tumor, surrounding liver parenchyma, and Glisson pedicle near the tumor were tested for K-ras and p53 mutations using the mutant allele-specific amplification method. For the retrospective study on patient outcomes, 194 patients who had undergone liver resections between 1980 and 2000 were analyzed according to their SMs. RESULTS: Of the 62 sets of samples from liver metastases, 39 were positive for K-ras and p53 gene mutations or both. Micrometastases in the liver parenchyma surrounding colorectal metastases were present in 2.0% (4/199) of tested samples and were located within 4 mm of the tumor border. Micrometastases via Glisson pedicle were more common (14.3% [3/21]), but these were also confined to a short distance from the tumor edge (</=5 mm). Of the 5 micrometastases detected by genetic analysis, only 2 were confirmed by histopathological examination. The analysis of patient outcomes demonstrated that the incidence of cut-end recurrence (relapse in the bed of resection) decreased from 20.0% to a range of 5.6% to 7.5% when the SM is 2 mm or more. The incidence of definite cut-end recurrence in patients with SMs less than 2 m, 2 to 4 mm, and 5 mm or wider was 13.3% (6/45), 2.8% (1/36), and 0% (0/102), respectively. The SM was not a significant prognostic factor in patient survival. CONCLUSIONS: Micrometastases around liver tumors are not common, and most are confined to the immediate vicinity of the tumor border. We propose an SM of 2 mm as a clinically acceptable minimum requirement, which carries approximately a 6% risk of margin-related recurrence. Because liver resection provides the only chance of cure, complete removal of the tumor with a minimum margin is justified when technically unavoidable because of the size, location, number of tumors, or successive resections.

Adult↗

PubMed2002

Less aggressive features of colorectal cancer with liver metastases showing macroscopic intrabiliary extension.

We have previously reported the frequent occurrence of bile duct invasion by liver metastases from colorectal cancer. We found that patients with macroscopic intrabiliary cancer growth survive longer after hepatectomy than those without this feature. In the present study, we analyzed the clinicopathological features of primary colorectal cancer showing macroscopic intrabiliary extension of liver metastases. We reviewed 217 patients who underwent initial hepatic resection for colorectal liver metastasis between 1992 and 1998, and analyzed the corresponding primary colorectal cancers clinicopathologically. Microscopic bile duct invasion was found in 89 of 217 cases (40.6%) and, of these cases, 23 (10.6%) had macroscopic intrabiliary extension. Histological sections of the corresponding primary colorectal cancer were available in eight (group A) of these 23 cases. These were compared with 20 cases, selected randomly, of colorectal cancer that did not show bile duct invasion and were diagnosed as liver metastases. These patients underwent hepatectomy during the same period as group A and were used as a control (group B). The histology of the primary tumors revealed well-differentiated adenocarcinoma in 100% of group A and in 25% of group B. The average maximum diameter of the primary tumor was 5.32 cm in group A and 3.61 cm in group B. Venous invasion was detected in 25% of group A and in 90% of group B (P < 0.01), while the incidences of lymphatic vessel invasion and lymph node metastases were similar between the groups. These data suggest that macroscopic intrabiliary extension could be a good indicator of a unique subgroup of colorectal cancers showing less aggressive features even though they develop liver metastases. Careful histological evaluation is important even for metastatic tumors.

Adenocarcinoma↗

PubMed2002

Pancreatic metastasis from renal cell carcinoma extending into the main pancreatic duct: a case report.

While metastasis to the pancreas is uncommon, it may occur from renal cell carcinomas (RCCs). We here present a case of pancreatic metastasis from RCC extending into the main pancreatic duct (MPD) in a 66-year-old Japanese man. The patient had a history of RCC treated with a radical nephrectomy 17 years previously and was found to have a mass approximately 2 cm in diameter in the body of the pancreas on radiological images. The patient was suspected of having pancreatic metastasis from RCC and underwent a distal pancreatectomy with splenectomy. Histologically, the tumor consisted of cells arranged in trabecular and alveolar structures with clear or eosinophilic granular cytoplasm, compatible with a metastatic RCC. The pancreatic tumor extended into the MPD with the stream of pancreatic juice. This condition is similar to RCC extension into the renal vein and the inferior vena cava. In conclusion, although extension into the MPD may be rare, such a growth pattern may be characteristic of metastases from RCCs.

Aged↗

PubMed2001

Preoperative portal embolization in patients with hepatocellular carcinoma.

The factors that contribute to the effect of portal vein embolization before hepatectomy for hepatocellular carcinoma are unclear. Sixty-six patients with hepatocellular carcinoma were enrolled in the study. Changes in liver function, portal vein pressure, and liver volume after embolization were examined. A multiple linear regression analysis was performed to identify factors that independently contributed to the effects of portal vein embolization. The acceptable volume ratio of the remnant liver was calculated from liver function and compared with the volume ratio of the non-embolized liver. No postoperative deaths were observed after portal vein embolization or hepatectomy. Serum total bilirubin and prothrombin time did not change significantly after portal vein embolization. In patients who underwent arterial embolization before portal vein embolization, aminotransferase levels increased significantly. The only factor that could significantly predict the atrophy effects of portal vein embolization was previous arterial embolization. The volume ratio of the non-embolized liver was smaller than the acceptable volume ratio of the remnant liver in 18 of 40 patients and increased over the acceptable volume ratio in all cases after portal vein embolization. Portal vein embolization induced atrophy or hypertrophy of the embolized or non-embolized liver sufficiently, even when the liver was dysfunctional or cirrhotic. The atrophy effects were significant, especially when arterial embolization had been performed before portal vein embolization.

Aged↗

PubMedDate not supplied

The repeated hepatectomy for frequent recurrence of hepatic metastasis from gastrointestinal stromal tumor of the stomach.

Although in recent years hepatic resection has become a safe procedure, there are few data on repeat liver resection for hepatic metastases from gastrointestinal stromal tumor. A 60-year-old Japanese man underwent partial gastrectomy and extended right hepatectomy for gastrointestinal stromal tumor of the stomach with liver metastasis. However, liver metastasis recurred at the interval of less than 1 year. Therefore, the patient underwent a total of six liver resections. The liver resections comprised four R0, one R1 and one R2 resection. To our knowledge, six times for liver resection performed on one patient is a maximum. This patient survived 43 months after the first surgery. Despite frequent recurrence of hepatic metastasis from gastrointestinal stromal tumor, repeated hepatectomy provides a survival benefit if complete removal of all tumorous masses appears possible.

Fatal Outcome↗

PubMedDate not supplied

Successful outcome after resection of pancreatic cancer with a solitary hepatic metastasis.

The presence of hepatic metastasis in pancreatic cancer has generally been considered to be a contraindication for surgery. However, the present case survived seven years after concomitant resection of pancreatic cancer and hepatic metastasis. This shows that hepatic metastasis may be a strong predictor of poor survival, but not a determinant of noncurability. Surgical resection may be an option for highly selected patients with pancreatic cancer complicated with hepatic metastasis.

Adult↗

PubMedDate not supplied

Endoscopic total layer resection with laparoscopic sentinel node dissection and defect closure for duodenal carcinoid.

Tiny duodenal carcinoid is easily treated by endoscopic mucosal resection method. On the other hand, this tumor develops in the deeper layer of the mucosa, therefore it invades like a submucosal tumor. The resection of the total layer is sometimes needed to get a tumor-free margin. Moreover, lymph node metastasis is not predicted only by tumor size. Laparoscopic surgery is less invasive compared with conventional open surgery. We describe a new method, endoscopic total layer resection with laparoscopic sentinel node dissection and defect closure. This type of combined method should be performed in order to help decide whether to convert to conventional lymph node dissection, or not.

Carcinoid Tumor↗

PubMedDate not supplied

Repeated resection for intra-abdominal and retroperitoneal liposarcomas: long-term experience in a single cancer center in Japan.

Intra-abdominal or retroperitoneal liposarcomas are huge, and local recurrence is a common event. There is still no consensus concerning debulking or repeated resection. Twelve patients who had surgery for intra-abdominal or retroperitoneal liposarcomas at the Cancer Institute Hospital (Tokyo, Japan) during 1981-2002 were enrolled. Eight patients underwent complete resection, for a resectability rate of 67%. Combined resection of adjacent organs was necessary to obtain clear margins in 10 of the 12 patients (83%). A patient who underwent R2 resection survived 13.2 years in a dormant state without tumor regrowth. Resection of second (five patients), third (three patients), or seventh (one patient) for local recurrence or regrowth tumors was successfully performed. A patient survived 21.5 years after four R0 resections and three R2 resections. Our experience suggests that both near-total and repeated resection might improve survival benefit.

Abdominal Neoplasms↗