Search PubMed⌕ Search

Biomedical subjects

M Sasako

Publications and source records attributed to M Sasako.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Problems of international standardization of gastric cancer surgery].

Treatment results of gastric cancer patients differ considerably between Japan and the West, even at the same stage of disease. This may be partly explained by the varying extent of local control and the "stage-migration" theory. There is an important conceptual difference concerning lymphadenopathy and lymphadenectomy: Japanese surgeons believe that lymph nodes are the governors of metastatic disease and thus that lymphadenectomy will result in cure, while in the West lymph nodes are seen merely as the indicators of systemic metastasis and thus lymphadenectomy serves only for staging. The UICC TNM system has recently abandoned the anatomical N-classification and adopted the numeric N-classification. Although this is a good prognostic indicator, it does not provide surgeons with any information for surgical decision-making. Japanese surgeons will continue to use the Japanese classification that has served as a guideline for standard D2 lymphadenectomy. To establish an international standard for gastric cancer treatment, both sides should make efforts to understand each other and discuss most practical and beneficial treatment modalities for patients in the respective medical environments.

Gastrectomy↗
PubMed2000

Early carcinoma of the gastric cardia in Japan: is it different from that in the West?

BACKGROUND: The incidence of adenocarcinoma of the gastric cardia has increased recently in the West. However, in Japan, most patients with gastric carcinoma have disease that is situated in the body and the distal stomach. The objectives of this study were to compare the clinicopathologic findings of patients with early gastric carcinoma (EGC) arising at the cardia and those with carcinoma in more distal parts of the stomach, then comparing the findings with those from patients with carcinoma of the gastric cardia in the West. METHODS: Three thousand one hundred forty-four patients with EGC who underwent surgical resection between 1962 and 1997 at the National Cancer Center Hospital in Tokyo were studied. Seventy patients with EGC at the cardia were compared with those who had lesions in the middle and lower parts of the stomach. The body mass index (BMI), smoking, and drinking were evaluated using all patients with cardia EGC and 344 patients in a matched cohort in the latter group. RESULTS: Seventy patients had an EGC located just at the cardia, whereas 2796 patients had lesions in the lower two-thirds of the stomach. The former lesions were different from those in the distal two-thirds of the stomach: More often, they were of an elevated type (34% vs. 14%, respectively, they were histologically well differentiated in 89% (vs. 59%), and there were more submucosal tumors (53% vs. 41%). The BMI, smoking, and drinking in the two groups were not different. The incidence of Barrett esophagus and gastroesophageal reflux disease (GERD) in patients with EGC were 2. 9% (2 of 70 patients) and 5.7% (4 of 70 patients), respectively. CONCLUSIONS: There were many significant differences in clinicopathologic characteristics between patients with carcinoma of the cardia and patients with carcinoma of the distal stomach in Japan. The incidence of early cardia carcinoma was very low in Japan, and obesity, smoking, drinking, Barrett esophagus, or GERD were not related to its occurrence, in contrast to reports in the West.

Adenocarcinoma↗
PubMed2000

Evaluation of the New International Union Against Cancer TNM staging for gastric carcinoma.

BACKGROUND: The lymph node (N) classification in the International Union Against Cancer (UICC) TNM staging system for gastric adenocarcinoma has been revised. The new classification is based on the number of positive regional lymph nodes instead of the anatomic location of the regional lymph node metastasis. Both classification systems were compared for prognostic significance. METHODS: A total of 4362 gastric carcinoma patients who underwent resection between 1969 and 1990 were analyzed. RESULTS: Thirteen percent of patients could not be staged according to the new system. Based on the previous classification, 647 patients were classified as pN1 and 711 patients as pN2. When reclassified, 587 patients remained pN1, 54 patients became pN2, and 6 patients became pN3. Of the 711 pN2 patients, 333 became pN1, 267 remained pN2, and 111 patients became pN3. Both lymph node classification methods defined groups with widely differing prognoses. The prognoses of patients classified as new pN2 were more homogeneous than those of the group classified as old pN2. Survival of new pT4/pN1 patients was significantly better than that of other subgroups in Stage IV. Nine potential prognostic factors, including lymph node metastasis, were studied in multivariate analysis. The hazard ratios were 1.38 (1.16-1.64) for pN1 and 2.55 (2.16-3.01) for pN2, based on the old classification. They were 1.51 (1.29-78) for pN1, 3.11 (2.56-3.78) for pN2, and 3.88 (2.98-5.05) for pN3, based on the new classification. CONCLUSIONS: The new N classification is superior as a prognostic factor to the old N classification, although there is inadequacy in stage grouping. [See editorial on pages 1763-5, this issue.]

Humans↗
PubMed2000

Gastric lymphography and detection of sentinel nodes.

The lymphatic drainage system of the stomach was studied using lymphography with various dyes, and several major routes have been shown. Gastric lymph channels are multidirectional and form complex networks. We conducted a retrospective study to know the first site of metastasis from small gastric cancers by examining 89 cases with only one lymph node metastasis. The perigastric nodal area close to the primary tumor was the first site of metastasis in only 62% of the cases. N2 metastasis without N1 involvement was seen in 13%. In order to identify sentinel nodes for local resection of gastric cancer, a novel method needs to be developed.

Carbon↗
PubMed2000

What is reasonable treatment for gastric adenocarcinoma?

From its pattern of metastasis and recurrence, gastric carcinoma can be recognized as a slow-growing malignancy whose local control is still the most important part of treatment. With application of asymptomatic population screening and awareness of the high risk of this disease among the general population in Japan, many early lesions and even noninvasive cancers have been detected. For such tumors as noninvasive ductal carcinoma of the breast, local resection has become the popular treatment, and endoscopic mucosal resection is used for many early lesions. For advanced cancers, extended lymph node dissection has been applied in Japan and some other countries. The treatment results have improved remarkably in these countries. There are several reasonable explanations for the effectiveness of extended nodal dissection, but it is still controversial because of reported excessive postoperative morbidity and mortality and lack of proof in a randomized controlled trial. The Dutch Gastric Cancer Trial could not prove the benefit of extended lymph node dissection, although some data suggest its benefit over limited dissection. Further clinical trials seem necessary to evaluate its value in Western countries, but such trials should be carried out in limited specialist centers to exclude technical bias of two types of operation.

Adenocarcinoma↗
PubMed2000

[Current status and problem of adjuvant chemotherapy for curatively resected gastric cancer].

Randomized controlled trials (RCT) on adjuvant chemotherapy for gastric cancer published in the West and Japan were reviewed. Although several small trials showed positive data, adjuvant chemotherapy for curatively resected gastric cancer has been thought to be ineffective in western countries. Results of Japanese RCTs also have not become evidence of its benefit. Despite this, suggestive data by non-predefined subset analyses of old RCTs have been misread as definitive evidence of benefit because of less understanding of clinical statistics in Japan. As a result most Japanese patients have received postoperative adjuvant chemoimmunotherapy. Recently understanding of clinical trial has spread gradually and well designed RCTs with sufficient sample size have been reported. First of all we have to determine the efficacy of adjuvant chemotherapy by carefully designed RCT using surgery alone arm as control.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1999

Extended lymph-node dissection for gastric cancer.

BACKGROUND: Curative resection is the treatment of choice for gastric cancer, but it is unclear whether this operation should include an extended (D2) lymph-node dissection, as recommended by the Japanese medical community, or a limited (D1) dissection. We conducted a randomized trial in 80 Dutch hospitals in which we compared D1 with D2 lymph-node dissection for gastric cancer in terms of morbidity, postoperative mortality, long-term survival, and cumulative risk of relapse after surgery. METHODS: Between August 1989 and July 1993, a total of 996 patients entered the study. Of these patients, 711 (380 in the D1 group and 331 in the D2 group) underwent the randomly assigned treatment with curative intent, and 285 received palliative treatment. The procedures for quality control included instruction and supervision in the operating room and monitoring of the pathological results. RESULTS: Patients in the D2 group had a significantly higher rate of complications than did those in the D1 group (43 percent vs. 25 percent, P<0.001), more postoperative deaths (10 percent vs. 4 percent, P= 0.004), and longer hospital stays (median, 16 vs. 14 days; P<0.001). Five-year survival rates were similar in the two groups: 45 percent for the D1 group and 47 percent for the D2 group (95 percent confidence interval for the difference, -9.6 percent to +5.6 percent). The patients who had R0 resections (i.e., who had no microscopical evidence of remaining disease), excluding those who died postoperatively, had cumulative risks of relapse at five years of 43 percent with D1 dissection and 37 percent with D2 dissection (95 percent confidence interval for the difference, -2.4 percent to +14.4 percent). CONCLUSIONS: Our results in Dutch patients do not support the routine use of D2 lymph-node dissection in patients with gastric cancer.

Aged↗
PubMed1999

Can sentinel node biopsy indicate rational extent of lymphadenectomy in gastric cancer surgery? Fundamental and new information on lymph-node dissection.

Lymph-node dissection has been regarded as an effective surgical treatment for gastric cancer in Japan. It reduces local recurrence and improves survival rate. Japanese-style systematic D2 lymphadenectomy is now being introduced in western countries for treatment of gastric cancer. This surgical procedure, however, is not simple and should be performed by experienced surgeons. And it is too early to apply sentinel node biopsy for reducing extent of lymphadenectomy because of so complicated lymphatic streams from the stomach and frequent skip- and micrometastases.

Humans↗
PubMed1999

[Practice guidelines in western countries].

The concept of clinical practice guidelines was established in the 1960's to reduce medical costs that had been increasing dramatically in the US. To reduce medical expenses without lowering the quality of medical care, thorough control of medical practices was undertaken by rationalization of these practices. Guidelines were started initially for social and economical reasons, but were eventually accepted widely by society for several reasons. First, the concept of patients' autonomy was widely accepted after 1970, which supported full disclosure of information to patients. Second, there was too much information, necessitating ranking by scientific certainty. Third, the risk of litigation for doctors in the USA increased dramatically during these years. Whether a medical practice follows the guidelines or not has become one of the most important issues in medical lawsuits. Fourth, there is a constant demand for the effective use of social resources. Methods for developing clinical practice guidelines are already established in many societies. The first step is an intensive review of relevant articles to generate evidence-based recommendations (EBR). Then, to formulate practice guidelines, these EBR are ratified and modified by clinicians to whom they apply. They are then reviewed by independent experts. After final adjustment of the EBR or guidelines for administrative reasons, they are adopted with a future expiry date. Practice guidelines are not actually adopted in European countries. However, the concept of guidelines is well appreciated and medical practice is based on scientific evidence. In socialistic European countries like Sweden, Denmark or the Netherlands, there is huge pressure to control limited social resources, leading to aggressive efforts to reduce unexplained and inappropriate variations in medical practice.

Evidence-Based Medicine↗
PubMed1998

Ignoring small lymph nodes can be a major cause of staging error in gastric cancer.

BACKGROUND: Stage migration in gastric cancer confounds establishment of standard treatment according to stage. METHODS: To determine how closely lymph nodes should be examined to report correct staging, 402 node-positive patients were evaluated retrospectively. A total of 23,233 lymph nodes were reviewed histologically and their maximum dimension was measured. Another 254 nodes from 12 patients were used to evaluate shrinkage after fixation and preparation of the histological slide. RESULTS: Metastasis was detected in 3142 nodes, 1163 with well differentiated tumours (WDTs) and 1979 with poorly differentiated tumours (PDTs). Mean(s.d.) size of metastatic nodes was 7.80(5.08) mm in all, 8.44(5.74) mm in WDTs and 7.42(4.62) mm in PDTs. Both positive and negative nodes shrank between 10 and 20 per cent during histological processing. If all nodes 5 mm or less in size when fixed are ignored 37.8 per cent of all metastatic nodes will be missed. Downstaging will occur in 14.9 per cent and 4.2 per cent of the cases if all nodes less than 6 and 4 mm respectively are ignored. CONCLUSION: To keep the rate of stage migration caused by this factor below 5 per cent, all lymph nodes 4 mm or more in size (5 mm when fresh) should be retrieved and examined.

Diagnostic Errors↗
PubMed1998

The outcome of surgical treatment for gastric carcinoma in the elderly.

Surgeons are increasingly being faced with the problem of treating elderly gastric carcinoma patients. The purpose of this study was to elucidate the feasibility of surgical treatment for these patients. Among 4740 gastric carcinoma patients treated from 1971 to 1990, 112 (2.4%) were aged 80 or over. The results of treatment in this elderly group were compared retrospectively with those in 2664 younger gastric carcinoma patients (aged 50-69, control group, 56.2%). The TNM stage distribution and the curative resection rates (75.9 vs 81.4%) were similar between the groups. Reduced nodal dissection was more common in the elderly group. The elderly had a higher incidence of preoperative risk factors (76.8 vs 53.1%) and 90-day mortality (10.7 vs 3.9%). However, the postoperative complication rates were similar between the groups. The 90-day mortality rates in the elderly group were higher in the subgroups undergoing total gastrectomy or D2 dissection. In the patients without pre-existing morbidity, the 30-day mortality, 90-day mortality and postoperative complications were similar between the groups. The 5-year survival rate after curative resection of the elderly group was significantly lower than that of the control group (44.4 vs 74.0%). This difference lost significance when non-cancer death was excluded (62.5 vs 79.9%). We believe that, although gastrectomy can be carried out safely in elderly patients, extended surgery should be limited to those without preoperative morbidity.

Aged↗
PubMed1998

Early gastric stump cancer following distal gastrectomy.

BACKGROUND: Gastric stump cancer (GSC) is usually diagnosed at an advanced stage, and consequently the prognosis is poor. AIMS: To investigate the clinicopathological characteristics of GSC at an early stage to assist in its identification, and thereby improve its prognosis. METHODS: Forty three patients with resected early GSC were compared with 156 patients with resected primary early cancer in the upper third of the stomach. RESULTS: Sixty five per cent (28/43) of the early GSC patients showed the elevated type endoscopically, although the frequency of the depressed type in GSC has tended to increase in the past five years. This occurred in less than 26% (40/156) of the primary early cancers. Half of the early GSCs were located on the lesser curvature (47%), and revealed differentiated adenocarcinoma (81%) histologically. The male:female ratio of early GSC cases was about 6:1, which was much higher than that in patients with primary early cancer. The five year survival rates of patients with early GSCs and early primary cancers were 84% and 95%, respectively. GSC had a favourable prognosis, if it was detected at an early stage. CONCLUSION: To detect early GSC, our results suggest that special attention should be given to elevated as well as depressed lesions on the lesser curvature of the stomach, particularly in men, during endoscopic examinations.

Adenocarcinoma↗