Shigekazu Ohyama

Indications for gastrectomy after incomplete EMR for early gastric cancer.

BackgroundAlthough the number of patients with early gastric cancer (EGC) treated by endoscopic mucosal resection (EMR) has increased, the appropriate strategy for treating those with incomplete resection has not been established.MethodsThis study analyzed 726 cases of EGC in patients treated by EMR between 1991 and 2000, in order to clarify the en-bloc and complete resection rates. We classified patients with incomplete resection into four groups according to the estimated risk of residual cancer or lymph node (LN) metastasis, determined from pathological findings of EMR specimens. We then analyzed 45 patients with EGC treated surgically after incomplete EMR, with the aim of eliciting the risk of residual cancer and LN metastasis.ResultsOf the 726 patients, 529 (72.9%) had an en-bloc resection, while 378 (52.1%) had a complete resection. Three hundred and nine patients were found to have mucosal cancer and lateral cut-end-positive status with no LN metastasis (group A). In this group, 18 patients (5.8%) had residual cancer, with the lesions in the majority of patients being limited to the mucosal layer. Group B consisted of 14 patients with differentiated and submucosal (sm1) depth cancers, with 1 patient having residual cancer and 2 patients having LN metastasis. Fifteen patients were classified as group C, with sm2 or greater and vertical cut end-negative status, with 2 showing residual cancer and 1 showing LN metastasis. Group D included 10 patients with vertical cut end-positive status. Four of these patients had residual cancer while 1 had LN metastasis.ConclusionWe recommend that patients in group A should have close follow-up or endoscopic treatment, while those in groups B, C, or D should be treated by gastrectomy associated with LN dissection.

Prognostic value of S-phase fraction and DNA ploidy studied with in vivo administration of bromodeoxyuridine on human gastric cancers

The authors studied the prognostic values of DNA ploidy pattern and proliferative activity with in vivo administration of bromodeoxyuridine in human gastric cancers. Fresh specimens surgically removed from 117 patients with gastric cancer were investigated by flow cytometric study using a monoclonal antibody to bromodeoxyuridine. DNA ploidy patterns were classified into four types according to the bivariate BrdUrd/DNA distribution: D1, tumors with single diploid population; D2, tumors which showed mosaic of diploid and aneuploid population; A1, tumors with single aneuploid population; and A2, several aneuploid populations without diploid population. The numbers of cases of each ploidy pattern were as follows: D1, 36 cases (30.8%); D2, 38 cases (32.5%); A1, 15 cases (12.8%); and A2, 27 cases (23.1%). DNA ploidy pattern and S‐phase fraction (SPF) showed no relation with clinicopathologic findings, except for type A2. In type A2, lymph node metastasis and lymphatic vessel invasion were observed more often than type D1. The SPF calculated from the bivariate BrdUrd/DNA distribution was higher in aneuploidy (D2, A1, and A2) than in diploidy (D1) (P < 0.01). Also, A2 exhibited a higher SPF than A1 (P < 0.01). Furthermore, SPF correlated with DNA index significantly (P < 0.01). Patients who showed aneuploid tumors, DNA ploidy type A2, or SPF of more than 10% survived 3 years less than those with diploid tumors, DNA ploidy type D1, or SPF of less than 10%, respectively (P < 0.05). By analyzing with the Coxs proportional hazards model, it is revealed that DNA ploidy and SPF are one of the independent factors of prognostic significance. The results indicated that the patients with aneuploid tumors or highly proliferative tumors had a poor prognosis and that DNA ploidy pattern and SPF were useful prognostic factors for gastric cancers.

Chronological changes of characteristics of early gastric cancer and therapy: Experience in the Cancer Institute Hospital of Tokyo, 1950–1994

Gastric cancer, the leading cause of death from cancer in Japan, has long been studied. We received our first patient with early gastric cancer in 1950 and have since treated 2382 patients with this cancer up to 1990. The percentage of early gastric cancers diagnosed has been on the increase following the improvement in diagnostic skills and the establishment of mass screening. At present, more than half of the gastric cancers presenting are in the early stages. Chronological changes in diagnoses of early gastric cancer are characterized by the increased findings of (a) small tumors less than 4 cm in diameter (b) depressed-type carcinoma (c) lesions of the upper part of the stomach, and (d) undifferentiated-type adenocarcinoma. The standard method of treatment for early gastric cancer was standard radical operation in the 1970s. In the 1980s endoscopic mucosal resection and limited operation were adopted and their use has been increasing annually. The prognosis for early gastric cancer is quite favorable (the 5-year survival rate is more than 90%), and it is regarded as a disease with good prognosis. To obtain still better therapeutic results, it is essential to increase the proportion of early gastric cancers where endoscopic mucosal resection or limited operation is indicated, and improve the techniques of those procedures.

Proliferative activity and malignancy in human gastric cancers significance of the proliferation rate and its clinical application

The authors sought useful indicators for predicting the proliferative activity of human gastric cancer and attempted to evaluate its clinical significance. One hundred seventy‐two patients with gastric cancer were entered in this study. All patients received bromodeoxyuridine at 200 to 1000 mg/body before laparotomy. Cell kinetics studies using the migration chase method were done for 56 patients, and the DNA synthesis time (Ts) was found to be prolonged in tumors, especially in aneuploid tumors, compared with normal mucosae. Ts correlated with bromodeoxyuridine (BrdUrd) labeling indices (LI) (r = 0.453, P < 0.0005) and DNA indices (DI) (r = 0.534, P < 0.0005). Thus, the DNA synthesis time was significantly prolonged in the tumors having a high S‐phase fraction or DNA aneuploidy. The result of multivariate analysis indicated that LI/DI was the most potent indicator for predicting the proliferation rate (PR), which was : calculated by the formula LI/Ts, and correlated significantly with PR (r = 0.863, P < 0.0001). As was clear from the result of Coxs proportional hazard model, the predieted proliferation rate (pPR) was the most notable factor for the prognosis because pPR correlated clinically with metastasis, such as that to liver and lymph nodes. The patients with a high pPR (> 10%) had a worse prognosis (4‐year survival rate: 16.3%) than did those with a low value (< 10%) (4‐year survival rate: 85.1%). In vitro pPR obtained by in vitro BrdUrd labeling of the specimens obtained at biopsy correlated significantly with the in vivo pPR (r = 0.960, P < 0.0001). The authors concluded that the proliferation rate was the most important factor in judging the malignancy of human gastric cancers and that this rate should be most helpful in determining the treatment and evaluating the prognosis of individual patients.

Laparoscopic esophagogastric circular stapled anastomosis: a modified technique to protect the esophagus.

Laparoscopic surgery is increasingly being applied to gastric cancer surgery, including proximal gastrectomy for the resection of cancer located in the upper gastric body. Despite the ease of use of stapling devices for end-to-end anastomosis, esophagogastric anastomosis is complicated by the narrow laparoscopic space, making the placement of an esophageal purse-string suture and anvil insertion into the fragile and contracted esophagus difficult. The aim of this study was to employ a novel esophagogastric anastomosis technique for laparoscopic surgery which may avoid esophageal breakdown. Eleven patients with early gastric cancer within the upper gastric body underwent laparoscopic proximal gastrectomy. The anvil of the stapler was introduced into the esophagus through a small gastrostomy, before transection of the esophagus. The esophageal-to-anterior gastric wall anastomosis was performed using a double-stapling technique, without the need to apply a purse-string suture. The mean operation time was 237 ± 15 min and estimated blood loss was 39 ± 21 ml. The postoperative course was uneventful in all 11 patients, with no anastomotic leakage observed. Two patients needed endoscopic balloon dilation of an anastomotic stricture 24 to 28 days postoperatively. This modified procedure of laparoscopic esophagogastric anastomosis after proximal gastrectomy for the resection of cancer is a simple, rapid, and atraumatic technique which reduces the risk of anastomotic insufficiency.

Left-sided approach for suprapancreatic lymph node dissection in laparoscopy-assisted distal gastrectomy without duodenal transection

Laparoscopy-assisted distal gastrectomy (LADG) with extended lymph node dissection has not yet been widely adopted for the treatment of gastric cancers because of the perceived complexity of the procedure. Suprapancreatic lymph node dissection is one of the most important and demanding procedures in this approach. The techniques of duodenal transection within the abdominal cavity or taping of the common hepatic or splenic artery had traditionally been adopted for suprapancreatic nodal dissection during open surgery. In 2005, we developed a new laparoscopic procedure to safely and simply perform suprapancreatic lymph node dissection in LADG. We introduced a left-sided approach for the dissection of lymph nodes in the left gastropancreatic fold, where the body of the stomach is turned over and lifted ventrally to expose the left gastropancreatic fold through the opened lesser sac, without duodenal transection, and the suprapancreatic lymph nodes are resected en bloc in reverse order, i.e., including the lymph nodes along the proximal splenic artery (station 11p), around the celiac artery (station 9), and along the common hepatic artery (station 8a). Between April 2005 and December 2007, a total of 391 patients with cT1,2 gastric cancer underwent this surgical approach. In all patients, surgery was completed safely with favorable outcomes; mean operating time was 239 min and mean blood loss was 63 ml. The complication rate was 4.6% (18/391); there were ten conversions (2.6%) and no mortality. The aim of the present study was to describe the surgical technique of our new approach for LADG with extended lymph node dissection and to evaluate the treatment outcomes achieved by this technique.

Survival Benefit of Pylorus-Preserving Gastrectomy in Early Gastric Cancer

BACKGROUND Pylorus-preserving gastrectomy (PPG) is performed in some patients for the treatment of early gastric cancer. The aim of this study was to investigate longterm survival for patients having PPG with extensive lymph node dissection, except for the suprapyloric nodes, for early gastric cancer. STUDY DESIGN From January 1995 to December 2006, 305 patients underwent PPG if they met the following criteria: cT1 (mucosa or submucosa), cN0 gastric cancer in the middle body of the stomach. Overall 5-year survival, cancer-related mortality, and freedom from recurrence were assessed retrospectively. RESULTS The median followup period was 61 months (range 27 to 144 months). Seven patients died, and the overall 5-year survival probability was 98%. Gastric cancer-related mortality was 0% and none of the patients had evidence of tumor recurrence. The accuracy of the preoperative diagnosis of T1 gastric cancer using endoscopy or endoscopic ultrasonography was 95.7%. CONCLUSIONS PPG may provide a longterm survival benefit for patients with clinically diagnosed T1 (mucosa or submucosa), cN0 gastric cancer in the middle body of the stomach, only when the accuracy of preoperative diagnosis can be assured.

Effects of reconstruction methods on a patient’s quality of life after a proximal gastrectomy: subjective symptoms evaluation using questionnaire survey

Background and aimsProximal gastrectomy is typically indicated in early gastric cancer of the upper third of the stomach. Esophagogastrostomy (EG) and jejunum interposition (JI) are often selected as reconstruction methods, although the more appropriate method of the two is unknown.Materials and methodsOne hundred and seven patients, who underwent a proximal gastrectomy followed by either an EG or a JI, were sent a questionnaire of 33 questions about subjective symptoms. Eighty-three patients (45 in the JI group and 38 in the EG group) returned the questionnaire. Results were compared between the two groups to identify the appropriate reconstruction method after a proximal gastrectomy. Also, changes in a patient’s body weight after surgery were compared.ResultsEarly and late dumping syndromes and gastroesophageal reflux associated symptoms were equally observed between the two groups. However, abdominal discomfort after meals (P = 0.008), continuous gastric fullness (P = 0.028), and hiccups between meals (P = 0.022) were often observed in the JI group. The loss of body weight was not significantly different between the two groups.ConclusionEG is a better reconstruction method compared to a JI after a proximal gastrectomy when evaluating subjective symptoms. Prospective study is warranted to clarify the better reconstruction method following proximal gastrectomy in terms of both subjective and objective symptoms.

Increased fat content and body shape have little effect on the accuracy of lymph node retrieval and blood loss in laparoscopic distal gastrectomy for gastric cancer.

BackgroundFat volume and large abdominal shape are known to disrupt the procedures of lymph node retrieval used in gastric cancer surgery. The present study examined the effect of increasing fat content on surgical outcomes, including estimated blood loss and the number of lymph nodes retrieved during gastrectomy.MethodsOf 154 patients, 50 underwent the conventional open procedure (OPEN) and 104 underwent laparoscopy-assisted distal gastrectomy (LADG). The BMI-related factors of total fat, subcutaneous fat, and visceral fat area, as well as the peritoneum–celiac axis distance were calculated by computed tomography. Regression analysis was used to determine the effects of BMI-related factors that obstruct the surgical procedures on the specific outcomes of estimated blood loss and the number of lymph nodes retrieved.ResultsIn the OPEN, but not in the LADG, increases in all BMI-related factors were related to increases in estimated blood loss. The increases in BMI, subcutaneous fat, and the peritoneum-celiac axis distances were related to decreased numbers of retrieved lymph nodes only in the OPEN. Only the factor of visceral fat at the celiac level was modestly associated with a decreased number of dissected lymph node in both groups.ConclusionsThe present study demonstrated that increased fat content and large body shape have little effect on the number of lymph nodes retrieved and blood loss in LADG. However, for patients undergoing conventional open distal gastrectomy, increased fat content and large body shape do impact on the amount of blood lost and the number of lymph nodes retrieved.

Previous Laparotomy is Not a Contraindication to Laparoscopy-assisted Gastrectomy for Early Gastric Cancer

BackgroundLaparoscopic procedures have generally been considered to be contraindicated in patients with a history of laparotomy because of a high risk of enteric injury during the procedure. Laparoscopy-assisted gastrectomy (LAG) has been used increasingly in the treatment of early gastric cancer, but its indication for patients with a history of laparotomy remains unclear. The aim of the present study was to estimate whether LAG is contraindicated for the patient with a history of laparotomy (PSURG).MethodsFrom January 2003 to March 2006, 139 patients with early gastric cancer underwent LAG with curative intent in our institute. Fifty were PSURG patients, and the remaining 89 patients underwent LAG without any history of laparotomy (NSURG). Operative and early postoperative outcomes were compared between the groups.ResultsAppendectomy and gynecological surgery were the predominant procedures performed in the PSURG group prior to undergoing LAG, involving 28 patients (56.0%) and 16 patients (32.0%), respectively. Detachment of adhesion above the umbilicus was required in 25 PSURG patients (50.0%). There was no significant difference in operative and postoperative results between the two groups, although 1 PSURG patient developed symptoms of bowel injury on the first postoperative day, probably caused during the laparoscopic procedure for dissection of a jejuno-jejunal adhesion.ConclusionsThere was no difference in outcome following LAG between the PSURG and NSURG groups in the present study. The PSURG patient is not contraindicated for LAG assuming careful attention is given for all operative procedures, including port insertion and dissection of intra-abdominal adhesions.