Mucinous carcinoma was associated with a lower response to pre-operative chemo-radiotherapy in this group of rectal carcinoma patients. Further studies are needed to determine its prognostic value.

The chronic myelogenous leukemic K562 cell line carrying Bcr-Abl tyrosine kinase is considered as pluripotent hematopoietic progenitor cells expressing markers for erythroid, granulocytic, monocytic, and megakaryocytic lineages. Here we investigated the signaling modulations required for induction of erythroid differentiation of K562 cells. When the K562 cells were treated with herbimycin A (an inhibitor of protein tyrosine kinase), r a s antisense oligonucleotide, and PD98059 (a specific inhibitor of MEK), inhibition of ERK/MAPK activity and cell growth, and induction of erythroid differentiation were observed. The r a s mutant, pZIPRas 6 1 l e u -transfected cells, K562-Ras 6 1 l e u , have shown a markedly decreased cell proliferation rate with approximately 2-fold doubling time, compared with the parental K562 cells, and about 60% of these cells have shown the phenotype of erythroid differentiation. In addition, herbimycin A inhibited the growth rate and increased the erythroid differentiation, but did not affect the elevated activity of ERK/MAPK in the K562-Ras 61leu cells. On the other hand, effects of PD98059 on the growth and differentiation of K562-Ras 61leu cells were biphasic. At low concentration of PD98059, which inhibited the elevated activity of ERK/MAPK to the level of parental cells, the growth rate increased and the erythroid differentiation decreased slightly, and at high concentration of PD98059, which inhibited the elevated activity of ERK/MAPK below that of the parental cells, the growth rate turned down and the erythroid differentiation was restored to the untreated control level. Taken together, these results suggest that an appropriate activity of ERK/MAPK is required to maintain the rapid growth and transformed phenotype of K562 cells.

Purpose:Laparoscopic intracorporeal colorectal anastomosis with double stapling technique is difficult because of unsuitable cutting angle in narrow pelvic cavity. For reasons of tilted and long linear staple line of rectal stump, circular anastomotic plane can make multiple intersections. The present study was designed to assess whether multiple intersections after double stapling technique is the risk factor of anastomotic complication in laparoscopic colorectal surgery.Materials and Methods:In total, 128 consecutive left colon and rectal cancer patients who underwent laparoscopic rectal resection with double stapling technique were enrolled in this study. In all cases, operator tried to reduce intersections by inversion and invagination techniques. They were subdivided into 3 groups: 58 patients with no intersection of staple lines (group A), 62 patients with 1 point of intersection (group B) and 8 patients with 2 points of intersection (group C). Intraoperative air leakage, incomplete cut ring, postoperative bleeding, anastomotic stenosis, and leakage were compared between the 3 groups.Results:Clinical anastomotic leakage was identified in 1 (group C) of 128 patients (0.7%). Overall anastomotic leakage rate was 0% (0/58) in group A, 0% (0/62) in group B, and 12.5% (1/8) in group C (P=0.001). In univariate analysis, intersections of staple lines were associated with anastomotic complications. There were no statistically significant differences between the 3 groups in multivariate analysis.Conclusions:The number of intersections of staple lines is associated with anastomotic leakage, and the inversion technique is a useful method for avoiding anastomotic leakage. Using an appropriate technique by skilled operator, double stapling technique for laparoscopic anterior resection is safe and feasible.

No abstract

Primary isolated extramedullary plasmacytoma is a rare tumor. Although it commonly involves nasopharynx or upper respiratory tract, only 10% of cases involves the gastrointestinal tract. Stomach and small intestine are the most commonly involved sites in the gastrointestinal tract. Primary isolated extramedullary plasmacytoma of colon is extremely rare. We report a case of 45-year-old man who presented with 1-year history of lower abdominal pain. Colonoscopy showed a colonic stricture about 50 cm from the anal verge. Colonoscopic biopsy showed lymphoid hyperplasia. On computed tomography, enhancing circumferential wall thickening and luminal narrowing with pericolic lymph node enlargement in the transverse colon was identified. Patient underwent extended left hemicolectomy. Histopathologic examination of resected colon identified an isolated primary colonic plasmacytoma of 1.7 cm in diameter with regional lymph node involvement (8/50 positive). To administer adequate treatment, further study about clinical features of primary isolated extramedullary plasmacytoma of colon is necessary.

Gastric cancer is the most common synchronous multiple primary cancers occurring concomitantly with colorectal cancers. Careful preoperative screening is necessary for the detection of multiple primary cancers in extracolonic sites in patients with colorectal cancers.

Purpose: Although multiple primary colorectal cancer has been recognized as a significant clinical entity, its clinical and pathological features and its prognosis are still controversial. The purpose of this study was to clarify clinical and pathological features of multiple primary colorectal cancer.Materials and Methods: Among 1669 patients who underwent surgery for primary colorectal cancer from January 1997 to June 2005, 26 patients (1.6%) with multiple primary colorectal cancer were identified. We reviewed clinical characteristics including diagnostic interval, lesions, operating methods, and TNM stage, and we defined the index lesion as the most advanced lesion among the synchronous lesions. For the purposes of the study, the colon and rectum were classified into three segments. The right-side colon included the appendix, cecum, ascending colon, hepatic flexure, and transverse colon, and the left-side colon included the splenic flexure, descending colon, and sigmoid colon.Results: Of the 26 patients with multiple primary colorectal cancers, nineteen patients were male and seven patients were female, with a mean age of 61.5 years. Nineteen patients had synchronous colorectal cancers and seven patients had metachronous colorectal cancers. In the metachronous cases, the mean diagnostic interval was 36.8 months. The site of the first lesion in metachronous colorectal cancers was the right colon in five cases (71.4%) and the left colon in two cases (28.6%), and the site of the second lesion was the rectum in six cases (55.5%), the right colon in three cases (33.3%), and the left colon in one case. The TNM stage of the second lesions in the metachronous colorectal cancers was stage II in four cases (57.1%), stage III in one case (14.3%), and stage IV in one case (14.3%). For the synchronous colorectal cancers, the operation methods were single-segment resection combined with endoscopic mucosal resection in five cases (26.3%), single-segment resection alone in six cases, two-segment resection in six cases, and total colectomy in two cases.

Bevacizumab is a monoclonal antibody that targets vascular endothelial growth factor (VEGF), and it has shown promise as a clinical agent against metastatic colorectal cancer, and particularly in combination with chemotherapy. Bowel perforation is a known risk that's associated with bevacizumab use, but the etiology is unknown. Here we report on two cases of metastatic colorectal cancer in which the patients suffered from intestinal perforation after chemotherapy with bevacizumab.