Kazuki Ueda

Infrequent mutations in the PTEN/MMAC1 gene among primary breast cancers

Recently PTEN/MMAC1, a candidate tumor suppressor gene, was isolated from chromosome 10q23‐24 and somatic mutations of this gene were detected in several malignancies including brain, prostate, and breast tumors. To investigate further the potential role of this gene in mammary carcinogenesis, we examined 69 primary breast cancers for mutations in PTEN/MMAC1 by means of polymerase chain reaction single‐strand conformation polymorphism and sequencing analysis. We detected only one somatic missense mutation, a change from T to C at codon 59 (TCA to CCA) resulting in substitution of Pro for Ser in the predicted protein. This site is located outside of phosphatase or phosphate‐acceptor motifs, but this codon encodes a residue that is conserved in homologous proteins, tensin and auxilin and is likely to be crucial for normal function of PTEN/MMAC1. Among the 69 tumors examined, three low‐frequency polymorphisms were found as well, one in the non‐coding region of exon 1 and one each in introns 2 and 7. Our results suggested that mutation of the PTEN/MMAC1 gene is not a major factor in the development of most primary breast cancers.

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.

Detection of a rectocele-like prolapse in the colonic J-pouch using pouchography: cause or effect of evacuation difficulties?

The functional outcome after a low anterior resection for rectal cancer is improved by a colonic J-pouch reconstruction. One functional problem with J-pouches is difficulty in evacuation, which is more common with large reconstructions. Since rectoceles are common findings on defecography in patients with evacuation difficulties, we proposed that a rectocele-like prolapse may be thus found in patients with large J-pouches. Pouchography was used to identifya rectocele-like prolapse (RP) in 26 patients with a 10-cm J-pouch (10-J group) and 27 patients with a 5-cm J-pouch (5-J group). Pouchography was performed at 3 months, 1 year, and 2 years after surgery. Functional assessments were performed 1 year postoperatively. Clinical function was evaluated using a questionnaire. The evacuation function was evaluated by the balloon expulsion and saline evacuation test. No patients had an RP at 3 months or 1 year after surgery. An RP was significantly more common in the 10-J group than in the 5-J group at 2 years after surgery (P=0.0374). An evacuation difficulty was significantly more common in the 10-J group than in the 5-J group. The evacuation function in the 10-J group was also significantly inferior to that in the 5-J group. An RP appearing 2 years after surgery is more common in patients with evacuation difficulties and large colonic J-pouch reconstructions.

Analysis of the clinical factors associated with anal function after intersphincteric resection for very low rectal cancer

BackgroundIntersphincteric resection (ISR) has been used to avoid permanent colostomy in very low rectal cancer patients. This study aimed to assess the surgical safety and oncologic and functional outcomes of ISR.MethodsThe records of 30 consecutive very low rectal cancer patients who underwent ISR without neoadjuvant therapy were retrospectively analyzed; survival and locoregional recurrence rates were calculated by the Kaplan-Meier method. Incontinence was assessed by a functionality questionnaire and the Wexner score.ResultsThe median distance between the distal margin of the dentate line was 10 mm. A total of 12, 4, and 14 patients underwent partial ISR, subtotal ISR, and total ISR, respectively. The mean distal resection margin was negative in all cases, and circumferential resection margin was positive in two cases. Morbidity was 33.3%: anastomotic stricture in seven patients, colonic J-pouch prolapse in two patients, and an anovaginal fistula in one patient. During the median, 56.2-month follow-up period, local, distant, and combined recurrences occurred in four, three, and two patients, respectively. The 5-year overall and disease-free survival rates were 76.5% and 68.4%, respectively. Local recurrence rates were 5.2% for the patients with Tis-T2 tumors as compared with 45.5% for those with T3 tumors (P = 0.008). The mean Wexner scores and stool frequencies, 12 months after stoma closure in 19 patients, were 11.5 and 6.6 per 24 h, respectively. Significant differences were not seen in the Wexner scores between partial ISR and subtotal/total ISR (11.8 ± 2.6 and 9.1 ± 5.6). Stool frequency (P = 0.02), urgency (P = 0.04), and fragmentation (P = 0.015) were worse in patients with anastomotic stricture than in those without; there was no symptom improvement in patients with anastomotic stricture.ConclusionsThe anastomotic strictures in patients undergoing ISR may have negatively affected anal function. For total ISR patients, at least, informed consent stating the possibility of a permanent colostomy is necessary.

Clinical Experience of Weekly Paclitaxel-Based Treatment as Preoperative Chemotherapy for Patients with Primary Breast Cancer

BackgroundPaclitaxel is an effective agent in the treatment of metastatic breast cancer. The aim of this study was to evaluate the safety and efficacy of weekly paclitaxel-based preoperative chemotherapy in patients with large operable breast cancer.MethodsPatients initially received paclitaxel as a 3-hour infusion at 175 mg/m2. Three weeks after initial administration, two cycles of three weeks of paclitaxel 80 mg/m2 over a 1 hour infusion followed by a one week break were given. Of 22 patients, 9 had stage II (tumor diameter greater than 3 cm), 4 stage IIIA, 7 stage IIIB, and 2 stage IV (with ipsilateral supraclavicular lymph node metastasis) cancer, respectively.ResultsExcluding stageN patients, the overall response rate to paclitaxel chemotherapy was 80%. Four of the 20 patients (20%) showed a clinical complete response (cCR). Two of these showed pathologic complete response and the other 2 had only the ductal component remaining. The primary tumor response and axillary lymph node downstaging following preoperative chemotherapy tended to be related in 16 patients with clinically positive nodes. Breast conserving surgery was performed as a result of down-staging in the 9 stage II patients. Grade 3 neutropenia occurred in one patient when 175 mg/m2 of paclitaxel was administered, but no serious side effects developed during the weekly administration of paclitaxel.ConclusionThe use of weekly paclitaxel-based preoperative chemotherapy appears to yield a significant anti-tumor effect without inducing serious drug-related adverse effects. Furthermore, the effectiveness of this treatment appears to result in a higher frequency of breast conserving surgery.

Laparoscopic excision of an epidermoid cyst arising from the deep abdominal wall.

Epidermoid cysts are the most common type of cutaneous cyst. However, their occurrence in the deep abdominal wall has not yet been reported. Here, we present the case of a 60-year-old woman who developed an epidermoid cyst in the deep abdominal wall, which was resected laparoscopically. The patient presented with right upper quadrant abdominal pain on admission to our hospital. Computed tomography revealed cholecystolithiasis and an incidentally identified well-defined hypoattenuating mass (62×47×65 mm) in the deep abdominal wall on the left side of the navel. We performed laparoscopic complete resection of the abdominal wall tumor followed by cholecystectomy. The excised specimen was a cyst covered with a smooth thin membrane and contained sludge. Histopathologic examination revealed an epidermoid cyst. This is a very rare case with no previous reports on a similar type of epidermoid cyst.

The potential clinical value of GML and the p53 gene as a predictor of chemosensitivity for colorectal cancer.

AbstractBackground. Adjuvant chemotherapy with 5-fluorouracil (5-FU) and mitomycin C (MMC) has commonly been used after resection of colorectal cancer. The aim of this study was to determine the predictive value of p53 mutation or the expression of GML, a target of p53, for sensitivity to 5-FU and MMC. Methods. We analyzed p53 mutations and the expression of GML in six colorectal cancer cell lines (SW837, DLD-1, RPMI4788, WiDr, HT-29, and HCT116), and examined the correlation between genetic changes and in-vitro chemosensitivity to MMC and 5-FU by measuring the colony-forming ability in these cell lines. We also introduced GML cDNA into a cell line that lacked endogenous GML expression to investigate changes in sensitivity to MMC and 5-FU. Results. The sensitivity to MMC was highest in HCT116, which had no p53 gene abnormalities and expressed endogenous GML, and lowest in RPMI4788 cells, which had neither p53 gene abnormalities nor expression of endogenous GML. For 5-FU treatment with 24-h exposure, HCT116 showed the highest sensitivity, and SW837, which had p53 mutations without expression of GML, showed the lowest sensitivity. The introduction of GML cDNA to RPMI4788 (RPMI4788-GML) showed that the sensitivity of RPMI4788-GML to MMC was enhanced almost to the level of HCT116 cells. However, when RPMI4788-GML were exposed to 5-FU for 24 h, the sensitivity of RPMI4788-GML was slightly increased compared with that of the parental cells, but was slightly lower than that of HCT116. Conclusion. GML expression and p53 mutation in colorectal cancer may be useful predictive genetic markers for sensitivity to MMC and 5-FU, respectively.

Laparoscopic Right-Sided Colectomy (Ileocecal Resection, Right Hemicolectomy, Extended Right Hemicolectomy)

The most common disease for right-sided colectomy is right-sided colon cancer. Although transverse colon cancer has been excluded from most of the major prospective randomized controlled trials due to technical concerns, laparoscopic surgery for right-sided colon cancer has been well established. The procedure of right-sided colectomy is divided into four parts: (1) mobilization of the right colon and its mesentery; (2) division of the vascular pedicles; (3) division of the lateral attachments, hepatic flexure, and omental attachments; and (4) specimen extraction and anastomosis. There are four commonly used approaches to a laparoscopic right-sided colectomy, namely, the medial, inferior, lateral, and superior approaches. The most important thing in all approaches is to create and maintain proper tension during the procedure by corporation between both hands of the assistant and the surgeon’s one hand. We will present a safe and steady procedure for right-sided colectomy with the regional lymph node dissection along the superior mesenteric vein.