Jin-ichi Hida

Functional outcome after low anterior resection with low anastomosis for rectal cancer using the colonic J-pouch. Prospective randomized study for determination of optimum pouch size.

PURPOSE: Functional outcome after low anterior resection with ultralow coloanal anastomosis for rectal cancer is improved by construction of a colonic J-pouchvs.straight anastomosis. Optimum size of this pouch has yet to be determined. Therefore, we initiated a prospective, randomized trial using 5-cm and 10-cm pouches to determine this size. METHODS: Patients with tumors 5 to 10 cm from the anal verge were included in the study. Before a low anterior resection anastomosis was performed, patients were randomized to either a 5-cm J-pouch group (5-J group) or a 10-cm J-pouch group (10-J group). Functional assessments were performed one year postoperatively. Clinical functions were evaluated using a functional scoring system. Physiologic functions, such as sphincter and reservoir function, were evaluated by anorectal manometry and evacuation function by the balloon expulsion and saline evacuation tests. RESULTS: Forty patients among 43 randomized patients were assessed for functional outcome one year postoperatively (5-J group, n=20; 10-J group, n=20). The functional score was similar for the two groups, although reservoir function in the 5-J group was significantly less than in the 10-J group. Sphincter function was similar between the two groups. Evacuation function in the 5-J group was significantly superior to that in the 10-J group. CONCLUSIONS: The 5-cm J-pouch conferred adequate reservoir function without compromising evacuation.

Distribution of metastatic lymph nodes in colorectal cancer by the modified clearing method

PURPOSE: The aim of this study was to clarify the distribution of lymph node metastasis in colorectal cancer. We also examined the relationship between the primary tumor (T) and the regional node (N) categories of the TNM (primary tumor, regional nodes, metastasis) classification. METHOD: Lymph nodes of surgical specimens in 311 consecutive patients with colorectal cancer were studied using the modified clearing method. RESULTS: Lymph node metastasis was seen in 59.2 percent of the total cases. The upward metastasis rate was 30.7 percent. In the longitudinal spread, most of the lymph node metastasis was seen within 10 cm. On the oral side in rectal cancer, there was no metastasis beyond 4 cm. The lateral metastasis rate in rectal cancer was 8.8 percent and in the lower rectum, the rate of cancer within 6 cm from the anal verge or beyond pT3 was much higher. CONCLUSION: In the TNM classification, there was no significant difference between colon and rectal cancer except pT1 with rectal cancer. In the lower rectal cancer within 6 cm from the anal verge or beyond pT3, there is a high risk of lateral metastasis, and lateral lymph node dissection or radiation therapy should be performed.

Enlargement of colonic pouch after proctectomy and colonanal anastomosis: Potential cause for evacuation difficulty

PURPOSE: Although the functional outcome after low anterior resection for rectal cancer using colonic J-pouch reconstruction is superior to that using conventional straight reconstruction, the one drawback of colonic J-pouch reconstruction is difficulty with evacuation. Recently it has been suggested that construction of a larger colonic J-pouch causes the evacuation difficulty. The purpose of this study was to elucidate the cause of evacuation difficulty with colonic J-pouch reconstruction. METHODS: We compared pouchography of 26 patients with 10-cm colonic J-pouch reconstructions (10-J group) and 27 patients with 5-cm colonic J-pouch reconstructions (5-J group) at three months, one year, and two years after surgery. Functional assessments were performed one year postoperatively. Clinical function was evaluated using a questionnaire. Evacuation function was evaluated by the balloon expulsion and saline evacuation tests. RESULTS: The greatest width of the pouch in the 10-J group in the anteroposterior view was significantly greater than that in the 5-J group at all three measurement times (3 months, 4.9vs. 4 cm;P=0.0011; 1 year, 9vs. 5.6 cm;P<0.0001; 2 years, 9.2vs. 5.8 cm;P<0.0001). The value in the 10-J group at one year after surgery was 1.9 times that at three postoperative months; in the 5-J group this ratio was 1.4. There was a significant difference between these ratios (P<0.0001). No significant difference existed between the values at two years and one year after surgery in either the 10-J or the 5-J group. An evacuation difficulty was significantly more common in the 10-J group than the 5-J group. Evacuation function in the 10-J group was significantly inferior to that in the 5-J group. CONCLUSIONS: The evacuation difficulty observed in patients with larger colonic J-pouch reconstructions is associated with excessive distention of the pouch occurring within one year of surgery.PURPOSE Although the functional outcome after low anterior resection for rectal cancer using colonic J-pouch reconstruction is superior to that using conventional straight reconstruction, the one drawback of colonic J-pouch reconstruction is difficulty with evacuation. Recently it has been suggested that construction of a larger colonic J-pouch causes the evacuation difficulty. The purpose of this study was to elucidate the cause of evacuation difficulty with colonic J-pouch reconstruction. METHODS We compared pouchography of 26 patients with 10-cm colonic J-pouch reconstructions (10-J group) and 27 patients with 5-cm colonic J-pouch reconstructions (5-J group) at three months, one year, and two years after surgery. Functional assessments were performed one year postoperatively. Clinical function was evaluated using a questionnaire. Evacuation function was evaluated by the balloon expulsion and saline evacuation tests. RESULTS The greatest width of the pouch in the 10-J group in the anteroposterior view was significantly greater than that in the 5-J group at all three measurement times (3 months, 4.9 vs. 4 cm; P = 0.0011; 1 year, 9 vs. 5.6 cm; P < 0.0001; 2 years, 9.2 vs. 5.8 cm; P < 0.0001). The value in the 10-J group at one year after surgery was 1.9 times that at three postoperative months; in the 5-J group this ratio was 1.4. There was a significant difference between these ratios (P < 0.0001). No significant difference existed between the values at two years and one year after surgery in either the 10-J or the 5-J group. An evacuation difficulty was significantly more common in the 10-J group than the 5-J group. Evacuation function in the 10-J group was significantly inferior to that in the 5-J group. CONCLUSIONS The evacuation difficulty observed in patients with larger colonic J-pouch reconstructions is associated with excessive distention of the pouch occurring within one year of surgery.

Results from pelvic exenteration for locally advanced colorectal cancer with lymph node metastases

PURPOSE: We examined the survival benefit of pelvic exenteration for locally advanced colorectal cancer with lymph node metastases, because this issue remains controversial. METHODS: Medical records of 50 patients who underwent curative pelvic exenteration for colorectal cancer were reviewed retrospectively. Nodal metastases were examined by the clearing method in 29 patients and by the conventional manual method in 21 patients. RESULTS: Invasion to contiguous pelvic organs was present in 40 patients (80 percent) and absent in 10 patients (20 percent). Node metastases were present in 33 patients (66 percent). Operative morbidity and mortality rates were 22 percent (11 patients) and 6 percent (3 patients), respectively. Respective five-year survival rates were 60 and 80 percent in the groups with and without organ invasion (no significant difference). Five-year survival rates in patients with nodal metastases was 54.6 percent but was significantly higher, 82.4 percent, in patients without nodal metastases. Five-year survival in 28 patients with both organ invasion and nodal metastases was 53.6 percent. CONCLUSIONS: Long-term survival was afforded by pelvic exenteration for locally advanced colorectal cancer with nodal metastases.

Optimal ligation level of the primary feeding artery and bowel resection margin in colon cancer surgery: the influence of the site of the primary feeding artery.

PURPOSEIn colon cancer surgery, it is recommended that en bloc resection involving extended lymphadenectomy, characterized as a hemicolectomy, be performed by ligating the primary feeding artery at a high position and resecting proximal and distal with 5-cm to 10-cm bowel margins. However, there is little evidence to unequivocally support such extensive lymphovascular resection.METHODSThe distribution of nodal metastases was obtained by the clearing method in 164 patients with colon cancer.RESULTSFor pericolic spread, for pT1 tumors, the distance from the primary tumor to a diseased node was 2.5 cm; for pT2, the distance was less than 5 cm; for 97.0 percent of pT3 tumors and 93.3 percent of pT4 tumors with nodes involved, the distance was less than 7 cm. For central spread, for pT1 tumors, the rate of spread to central nodes was 0 percent; for pT2, the rate of spread was 20.0 percent to intermediate nodes (for tumors more than 5 cm from the feeding artery, the rate for central nodes was 0 percent); for pT3, the rate was 30.6 percent to intermediate nodes and 15.3 percent to main nodes; for pT4, the rate was 44.4 percent to intermediate nodes and 22.2 percent to main nodes. For curative resection cases with pT3 tumors more than 7 cm from the feeding artery, the rate to central nodes was 0 percent.CONCLUSIONSIn T1 tumors, central node dissection is not required, but resection with proximal and distal 3-cm margins are required; in T2, central node dissection that includes the intermediate node should be performed in addition to resection with proximal and distal 5-cm margins. In T3 and T4, central node dissection that includes the main node should be performed in addition to resection with proximal and distal 7-cm margins. However, for T2 more than 5 cm from the primary feeding artery, and for T3 more than 7 cm from the primary feeding artery, proximal and distal resection alone may be adequate.

Indications for colonic J-pouch reconstruction after anterior resection for rectal cancer

PURPOSE: Functional outcome after anterior resection for rectal cancer is improved by colonic J-pouch reconstruction compared with straight anastomosis. The indications for colonic J-pouch reconstruction have yet to be determined. Therefore, we attempted to determine the level at which J-pouch reconstruction provides an advantage over straight anastomosis. METHODS: A total of 48 patients who underwent 5-cm colonic J-pouch reconstruction (J-pouch group) and 80 patients who underwent straight anastomosis (straight group) underwent functional assessment one year postoperatively. RESULTS: The functional outcome in the J-pouch group was significantly better than that in the straight group when the distance of the anastomosis from the anal verge was less than 8 cm. The difference was particularly obvious when the level of the anastomosis was below 4 cm. However, functional outcome in the straight group when the anastomosis was between 9 and 12 cm from the anal verge was also satisfactory and did not differ from that in the J-pouch group when the anastomosis was between 5 and 8 cm from the anal verge. CONCLUSIONS: Colonic J-pouch reconstruction is indicated when the distance of anastomosis from the anal verge is less than 8 cm, and it is essential when the distance is less than 4 cm.

Gene expression analysis in colorectal cancer using practical DNA array filter

PURPOSE: We examined the usability of a newly developed, compact-sized DNA array filter for studying the gene expression pattern of individual colorectal cancer. METHODS: Complementary DNA probes were prepared from mRNA extracted from colonic cancer specimens and adjacent normal mucosa and then were labeled with chemiluminescence. These labeled probes were allowed to bind to the gene fragments on the filter. A specialized scanning charge-coupled device camera measured the intensity of each chemiluminescent spot, which is an indicator of the degree to which a specific gene is expressed. Gene expression image was quantified into intensity of signals by using computer software. RESULTS: Characteristic gene expression patterns were obtained from the colonic cancer cell line, RPMI4788, and the leukemia cell line, HL60, by using this compact-sized DNA array filter in the preliminary experiment. Up-regulation of nm23, TIMP1, VEGF, and cyclin E and down-regulation of some tumor suppressor genes (p53, TOSO, and SIVA),β-catenin, and metallothionein were observed in colonic cancer specimen when compared with those of normal mucosa. CONCLUSIONS: We have obtained unique gene expression patterns from colorectal cancer and normal tissue by using a newly developed compact-sized DNA array filter system. Collecting, storing, and analyzing of gene expression data from many samples of colorectal cancer will enable us to identify distinct subsets of patients based on molecular characteristics in the near future.

The extent of lymph node dissection for colon carcinoma

The surgeon is no longer able to palpate the mesocolon for lymph node metastases during laparoscopic colectomy. The extent of lymph node dissection should be determined beforehand for cancer control.

Second-look operation for recurrent colorectal cancer based on carcinoembryonic antigen and imaging techniques

PURPOSE: The usefulness of postoperative carcinoembryonic antigen (CEA) monitoring and improvements in imaging techniques have renewed enthusiasm for second-look operations (SLO) as the most effective treatment for recurrent colorectal cancer by reresection following early detection. The aim of our study is to evaluate the role of CEA and imaging techniques-directed SLO. METHODS: Seven hundred fifty-six patients with Dukes Stages B and C, who had undergone curative resection, were monitored postoperatively using CEA and imaging techniques. An SLO was performed on any potentially resectable recurrence, and in addition, an SLO was done when a persistently rising CEA value was detected. RESULTS: Recurrence developed in 18.8 percent (142/756) of patients, and 90.8 percent (129/ 142) of the recurrences were detected within the first three years following curative resection. When comparing carcinomas of the colon with that of the rectum, the former were associated with significantly more hepatic and intra-abdominal recurrences, whereas the latter had significantly more locoregional and pulmonary recurrences. Seventy-two patients underwent SLO. Of these patients, 54.2 percent (39/72) had all of their disease resected, and 1.4 percent (1/72) had no detectable disease at the SLO. Among the 142 patients with recurrence, 71 (50 percent) patients underwent SLO. The resectable group at SLO carried a significantly better survival than the unresectable recurrence group (41.3vs.5.2 percent;P<0.01). CONCLUSIONS: Complete removal of colorectal cancer recurrences by SLO, on the basis of postoperative, follow-up CEA and imaging technique findings, results in improved survival.

Lymph node ratio is a powerful prognostic index in patients with stage III distal rectal cancer: a Japanese multicenter study

PurposeThe present study aims to define the prognostic impact of the lymph node ratio (LNR) in patients with stage III distal rectal cancer.MethodsWe analyzed data from 501 patients who underwent curative resection (total mesorectal excision, TME) for stage III distal rectal cancer at 12 institutions between 1991 and 1998. Patients were divided into four groups according to quartiles based on LNR.ResultsAmong the 501 patients, 381 underwent TME with pelvic sidewall dissection (PSD). The median numbers of lymph nodes retrieved with and without PSD were 45 and 17, respectively (P < 0.0001). Forty-nine patients with lymph node retrieved less than 12 were excluded from further analyses. Among various clinicopathological parameters, univariate analysis identified age (P = 0.0059), histological grade (P < 0.0001), depth of tumor invasion (P = 0.0003), and number of positive nodes (P < 0.0001) and LNR (P < 0.0001) as prognostic factors. The Cox proportional hazards model revealed that age (P = 0.014), histological grade (P < 0.0001), depth of tumor invasion (P = 0.0002), and LNR (group 3, P = 0.0012; group 4, P < 0.0001) were independent prognostic factors. When the American Joint Committee on Cancer (AJCC) seventh staging system was added as a covariate, both AJCC stage (P < 0.0001) and LNR (P < 0.0001) were independent prognostic factors.ConclusionsAdding the LNR concept to the AJCC cancer staging system will improve accuracy in evaluating the nodal status of distal rectal cancer.