Biomedical subjects

P Gervaz

Publications and source records attributed to P Gervaz.

At least 19 recordsLinked to original sources

PubMed2006

[Surgical treatment of duodenal stenosis in Crohn's disease].

Crohn's disease may involve any part of the alimentary tract, including the stomach and duodenum. We report herein the case of a 22 year-old male in whom Crohn disease was diagnosed due to weight loss in relation with a stenosis of the first and second parts of the duodenum. A gastrojejunostomy was performed with a good subsequent result. The initial management of a Crohn's disease with involvement of the duodenum is medical. When there is an indication for surgery, a gastroenterostomy is preferred, albeit with a high incidence of outlet obstruction and marginal ulceration.

Adult↗

PubMed2006

Results from percutaneous drainage of Hinchey stage II diverticulitis guided by computed tomography scan.

BACKGROUND: Percutaneous abscess drainage guided by computed tomography scan is considered the initial step in the management of patients presenting with Hinchey II diverticulitis. The rationale behind this approach is to manage the septic complication conservatively and to follow this later using elective sigmoidectomy with primary anastomosis. METHODS: The clinical outcomes for Hinchey II patients who underwent percutaneous abscess drainage in our institution were reviewed. Drainage was considered a failure when signs of continuing sepsis developed, abscess or fistula recurred within 4 weeks of drainage, and emergency surgical resection with or without a colostomy had to be performed. RESULTS: A total of 34 patients (17 men and 17 women; median age, 71 years; range, 34-90 years) were considered for analysis. The median abscess size was 6 cm (range, 3-18 cm), and the median duration of drainage was 8 days (range, 1-18 days). Drainage was considered successful for 23 patients (67%). The causes of failure for the remaining 11 patients included continuing sepsis (n = 5), abscess recurrence (n = 5), and fistula formation (n = 1). Ten patients who failed percutaneous abscess drainage underwent an emergency Hartmann procedure, with a median delay of 14 days (range, 1-65 days) between drainage and surgery. Three patients in this group (33%) died in the immediate postoperative period. Among the 23 patients successfully drained, 12 underwent elective sigmoid resection with a primary anastomosis. The median delay between drainage and surgery was 101 days (range, 40-420 days). In this group, there were no anastomotic leaks and no mortality. CONCLUSION: Drainage of Hinchey II diverticulitis guided by computed scan was successful in two-thirds of the cases, and 35% of the patients eventually underwent a safe elective sigmoid resection with primary anastomosis. By contrast, failure of percutaneous abscess drainage to control sepsis is associated with a high mortality rate when an emergency resection is performed. The current results demonstrate that percutaneous abscess drainage is an effective initial therapeutic approach for patients with Hinchey II diverticulitis, and that emergency surgery should be avoided whenever possible.

Abdominal Abscess↗

PubMed2006

Laparoscopic versus open resection for appendix carcinoid.

BACKGROUND: Since an increasing number of appendectomies are performed via laparoscopy, it is crucial to determine the impact of this approach on appendix carcinoid (AC) outcome. The goal of this study was to compare results of laparoscopic (LAP) versus open (OP) appendectomy for AC according to intend to treat approach. METHODS: A retrospective review (1991-2003) identified 39 patients (median age, 36 years; range, 12-83) treated by laparoscopy (LAP) or laparotomy (OP) for AC in a single institution. Follow-up was complete for all patients (median, 67 months; range, 4-132). RESULTS: Most cases had associated acute appendicitis (64%). Median carcinoid size was 1.1 cm (range, 0.3-5) and 0.4 cm (range, 0.2-3) in the LAP and OP groups, respectively. LAP and OP were performed in 21 (54%) and 18 (46%) patients, respectively. Surgical margins were positive in two patients in the LAP group and one patient in the OP group (p = 0.6). Right colectomies were performed for AC >2 cm in five patients after LAP and in four patients after OP (p = 0.9). Actuarial 5-year survival rates were 100 and 94% in the LAP and OP groups, respectively (p = 0.2). Two patients died in the OP group, one due to metastatic carcinoid and the other due to metachronous colorectal cancer. Synchronous or metachronous colorectal carcinomas developed in six patients (15%). CONCLUSION: Laparoscopic appendectomy is a safe procedure for AC, with carcinologic and long-term results similar to those of conventional appendectomy. Thus, pre- or per-operative suspicion of AC is not a contraindication to LAP. Prognosis of AC appears more dependent on carcinoid malignant potential or associated tumors. Risk for developing colorectal adenocarcinoma is high in AC patients and warrants follow-up of all patients with colonoscopic screening.

Adolescent↗

PubMed2006

An audit of surgical management of gastrointestinal stromal tumours (GIST).

AIM: To analyze GIST outcome after primary resection and to determine if a new grading system could adequately predict there prognosis. METHODS: A retrospective review (1993-2002) identified 80 patients who underwent primary surgical resection for, c-KIT positive, GIST. Follow-up was complete for all patients (median follow-up 42, range 1-132, months). GIST were classified as low or high grade according to the following parameters: size, mitotic rate, mitotic index (MiB1), presence of necrosis, invasion of adjacent structure and presence of metastasis. RESULTS: GIST originated from the stomach (46), small bowel (30), colon and rectum two and mesentery two. At surgery, 94% of cases presented with localized disease and 6% blood born metastasis with or without lymph node invasion. Resections were complete (R0) in 72 cases. R0 resection correlated with prognosis (p<0.01). Sixty GIST were classified as low grade (median follow-up 60 months) and 20 as high grade (median follow-up 27 months). Five-year actuarial survival of patients with low or high grade GIST were of 95 and 21%, respectively, (p<0.001). CONCLUSION: Prognosis of GIST after surgical treatment is influenced by completeness of primary resection and tumour malignant potential. Low grade GIST have an excellent prognosis after surgery alone, while high grade GIST have a high rate of recurrence after primary resection. Adjuvant treatment should be advocated for patient with either high grade GIST or after incomplete primary resection. The presented grading system can reliably predict GIST outcome after primary surgical treatment. Complete surgical resection offers good chance of cure for low grade GIST, while for high grade GIST surgery alone is not sufficient. The presented grading system could be used to identify patients who may benefit of adjuvant treatment with imatinib mesylate after GIST resection.

Adult↗

PubMed2006

Molecular biology of squamous cell carcinoma of the anus.

BACKGROUND: Squamous cell carcinoma of the anal canal provides a model for studying the contribution of human papillomavirus (HPV) and human immunodeficiency virus (HIV) infection to the development of neoplasia. This paper reviews the existing literature relating to the molecular biology of anal squamous cell carcinoma and proposes a theory of pathogenesis. METHODS: A Medline literature search was performed to identify English articles on the pathogenesis of squamous cell carcinoma of the anus; further articles were obtained from the references quoted in the literature initially reviewed. RESULTS: HPV infection and subsequent HPV DNA integration are necessary, but not sufficient, to cause cancer progression. Loss of heterozygosity at 11q23 is the most consistent genomic change observed. Loss of heterozygosity at 17p, 18q and 5q is frequently observed in tumours of HIV-negative patients, but not in those of HIV-positive patients. Current data suggest that mutations in p53, DCC and APC tumour suppressor genes contribute to the stepwise progression of anal squamous cell carcinoma in immunocompetent individuals. CONCLUSION: In comparison with immunocompetent individuals, HIV-positive patients have persistent HPV infection in the anal canal. In this population, microsatellite instability, rather than chromosomal instability, appears to be a preferred pathway for rapid progression towards invasive carcinoma.

Anus Neoplasms↗

PubMed2006

Percutaneous CT scan-guided drainage vs. antibiotherapy alone for Hinchey II diverticulitis: a case-control study.

PURPOSE: CT-scan-guided percutaneous abscess drainage of Hinchey Stage II diverticulitis is considered the best initial approach to treat conservatively the abscess and to subsequently perform an elective sigmoidectomy. However, drainage is not always technically feasible, may expose the patient to additional morbidity, and has not been critically evaluated in this indication. This study was undertaken to compare the results of percutaneous drainage vs. antibiotic therapy alone in patients with Hinchey II diverticulitis. METHODS: This was a case-control study of all patients who presented in our institution with Hinchey Stage II diverticulitis between 1993 and 2005. Thirty-four patients underwent abscess drainage under CT-scan guidance (Group 1), and 32 patients were treated with antibiotic therapy alone (Group 2), in most cases because CT-scan-guided abscess drainage was considered technically unfeasible by the interventional radiology team. Initial conservative treatment was considered a failure when: 1) emergency surgery had to be performed, 2) signs of worsening sepsis developed, and 3) abscess recurred within four weeks of drainage. RESULTS: The median size of abscess was 6 (range, 3-18) cm in Group 1 and 4 (range, 3-10) cm in Group 2 (P = 0.002). Median duration of drainage was 8 (range, 1-18) days. Conservative treatment failed in 11 patients (33 percent) of Group 1, and in 6 patients (19 percent) of Group 2 (P = 0.26). Ten patients (29 percent) in Group 1 and five patients (16 percent) in Group 2 underwent emergency surgery (P = 0.24); there were four postoperative deaths (26.6 percent) in this subgroup. Twelve patients (35 percent) in Group 1 and 16 patients (50 percent) in Group 2 subsequently underwent an elective sigmoid resection (P = 0.31). In this subgroup of patients, there was neither anastomotic leakage nor postoperative death. CONCLUSIONS: Emergency surgery for Hinchey Stage II diverticulitis carries a high mortality rate and should be avoided. To achieve this, antibiotic therapy alone seems to be a safe alternative, whenever percutaneous drainage is technically difficult or hazardous. Actually, our data did not demonstrate any benefit of CT scan-guided percutaneous abscess drainage, suggesting that the role of interventional radiology techniques in this indication deserves further critical evaluation.

Abscess↗

PubMed2006

Sphincter-preserving radiation therapy for rectal cancer: a simulation study using three-dimensional computerized technology.

BACKGROUND: The acquisition of detailed computerized tomography (CT) imaging at the time of simulation, along with three-dimensional (3D) treatment planning software has been integrated with radiation delivery hardware to create the modality known as 3D conformal radiotherapy (3DXRT). This approach provides, in theory, a means to selectively subtract the anal sphincter from the high-dose field of irradiation in patients with stage II and III adenocarcinomas of the mid-rectum scheduled for low anterior resection (LAR). HYPOTHESIS: Implementation of 3DXRT with sphincter blocking may be a feasible strategy to reduce the dose of radiation distributed to the anal canal without reduction in the dose distribution to the gross tumour volume (GTV) plus adequate margins. METHODS: Pretreatment simulation CT scans of 10 patients with rectal cancers located between 5 and 10 cm from the anal verge were retrieved from a computerized database. Radiation oncologists and colorectal surgeons defined the contours of the GTV and the anal sphincter, respectively, on successive CT scan slices. These contours provided the volumetric data required to quantify dose distribution and compute dose-volume histograms. The standard mode of pelvic irradiation planned with CT simulation was compared with a 'virtual CT simulation' approach, in which a sphincter block was added to the protocol. RESULTS: The mean distance of tumours from the anal verge was 6.3 cm. In the virtual simulation treatment plan, a 2-cm margin separated the sphincter block from the lower limit of the GTV. The mean volume of the anal sphincter was 16.1 +/- 3.5 cm(3). The dose distributed to the GTV in the real plan and in the virtual simulated block plan were 51.7 +/- 1.4 and 51.6 +/- 1.4 Gy respectively (P = 0.85). By comparison the mean dose distributed to the anal sphincter was dramatically reduced by using a sphincter block (33.2 +/- 12 Gy vs 6.4 +/- 4.1 Gy, P < 0.001). CONCLUSION: During a course of radiotherapy for most low- or mid-rectal cancers, the anal canal is included within the field of irradiation with a mean dose distribution to the sphincter of 33 Gy. Evaluation of 3DXRT with full sphincter block (mid-rectum) and partial sphincter block (distal rectum) is a feasible strategy to decrease the volume of anal sphincter carried to full dose without reduction in dose to the GTV. This approach, by minimizing treatment-induced damage to the anal sphincter, might improve functional outcome of LAR.

Anal Canal↗

PubMed2005

Oxaliplatin combined with irinotecan and 5-fluorouracil/leucovorin (OCFL) in metastatic colorectal cancer: a phase I-II study.

BACKGROUND: A phase I-II multicenter trial was conducted to define the maximal tolerated dose and describe the activity of an OCFL combination using oxaliplatin (OHP), irinotecan (CPT-11) and 5-fluorouracil (FU)/leucovorin (LV) in metastatic colorectal cancer (CRC). PATIENTS AND METHODS: CRC patients not pretreated with palliative chemotherapy, with performance status < or =1 and adequate haematological, kidney and liver function, were eligible. Treatment consisted in weekly 24-h infusion 5-FU (2300 mg/m(2))/LV (30 mg) and alternating OHP (70-85 mg/m(2), days 1 and 15) and CPT-11 (80-140 mg/m(2), days 8 and 22) repeated every 5 weeks. OHP and CPT-11 were escalated in cohorts of three to six patients. RESULTS: Thirty patients received a median of five cycles. Dose-limiting toxicity occurred at dose level 3, and the recommended dose was OHP 70 mg/m(2), CPT-11 100 mg/m(2), LV 30 mg and 5-FU 2300 mg/m(2)/24 h. Grade > or =3 toxicities were diarrhea 23%, neutropenia 20%, fatigue 7%, and neurologic 7%. Two febrile neutropenia episodes (one fatal) were recorded. Among 28 patients with measurable disease (90%), we observed two complete and 20 partial responses; overall RR was 78% (95% CI, 59% to 92%). Median time to progression and overall survival were 9.5 and 25.4 months, respectively. Seven patients underwent liver metastases resection. CONCLUSION: OCFL is an overall well tolerated regimen with very high efficacy, which makes it most suitable for tumour control before surgery of metastatic disease.

Adult↗

PubMed2005

Randomized clinical trial of mechanical bowel preparation versus no preparation before elective left-sided colorectal surgery.

BACKGROUND: Mechanical bowel preparation (MBP) is performed routinely before colorectal surgery to reduce the risk of postoperative infectious complications. The aim of this randomized clinical trial was to compare the outcome of patients who underwent elective left-sided colorectal surgery with or without MBP. METHODS: Patients scheduled for elective left-sided colorectal resection with primary anastomosis were randomized to preoperative MBP (3 litres of polyethylene glycol) (group 1) or surgery without MBP (group 2). Postoperative abdominal infectious complications and extra-abdominal morbidity were recorded prospectively. RESULTS: One hundred and fifty-three patients were included in the study, 78 in group 1 and 75 in group 2. Demographic, clinical and treatment characteristics did not differ significantly between the two groups. The overall rate of abdominal infectious complications (anastomotic leak, intra-abdominal abscess, peritonitis and wound infection) was 22 per cent in group 1 and 8 per cent in group 2 (P = 0.028). Anastomotic leak occurred in five patients (6 per cent) in group 1 and one (1 per cent) in group 2 (P = 0.210) [corrected] Extra-abdominal morbidity rates were 24 and 11 per cent respectively (P = 0.034). Hospital stay was longer for patients who had MBP (mean(s.d.) 14.9(13.1) versus 9.9(3.8) days; P = 0.024). CONCLUSION: Elective left-sided colorectal surgery without MBP is safe and is associated with reduced postoperative morbidity.

Adult↗

PubMed2004

Cyclin D1, cyclin E, and p21 have no apparent prognostic value in anal carcinomas treated by radiotherapy with or without chemotherapy.

The purpose of this study was to assess the potential prognostic and/or predictive value of the expression of cyclin D1, cyclin E, and p21 protein in a series of 98 anal carcinomas (T1-4, N0-3) treated by radiotherapy with (51) or without (47) chemotherapy in one institution. Correlation with Mib1 index and p53 expression was also investigated. Median follow-up for surviving patients was 124 months (range: 30-266). Immunohistochemical staining was performed on pretreatment biopsies, applying a standard ABC technique for cyclin D1 (clone DSC6, DAKO, 1 : 300), cyclin E (clone 13A3, Novocastra, 1 : 100), p21(WAF/CIP1) (clone SX118, DAKO, 1 : 50), p53 (clone DO7, DAKO, 1 : 200), and Mib1 (Ki-67, Dianova, 1 : 20). Tumours were classified into low- or high-expression groups according to the expression level of the protein considered. High expression was found in 51% of tumours for cyclin E, in 33.7% for cyclin D1, and in 65% for p21. None of those factors were significantly associated with clinical variables such as advanced T or N categories. In a monovariate analysis, advanced T and N categories and longer overall treatment time were the only variables that correlated significantly with low rate of local control (LC) and disease-free survival. However, in a subgroup analysis, high p21 expression correlated with a trend for significantly higher 5-year LC (87 vs 68%, P=0.07) in the N0 patients. The results of this study suggest that the cell-cycle proteins investigated are unlikely to be clinically useful in predicting treatment response or prognosis in patients with anal carcinomas.

Adult↗

PubMed2004

Perineal rectosigmoidectomy for rectal prolapse: role of levatorplasty.

BACKGROUND: The management of full thickness rectal prolapse remains controversial. Although abdominal approaches have a lower recurrence rate than do perineal operations, they are associated with a higher morbidity. The aim of this study was to compare the outcomes of perineal rectosigmoidectomy with and without levatorplasty. METHODS: Between 1989 and 1999, a total of 109 consecutive patients (10 men) underwent 120 perineal procedures. These patients were retrospectively evaluated in two groups on the basis of the type of surgery received: perineal rectosigmoidectomy (PRS) or perineal rectosigmoidectomy with levatorplasty (PRSL). Subsequent functional outcome and physiological parameters were assessed. RESULTS: The patients had a mean age of 75.7 years (range, 23.0-94.8 years) and they were followed for an overall mean (in both groups combined) of 28.0 months (range, 0.4-126.4 months) after surgery. Mean duration of surgery was 78.1 min (SD=25.9) and 97.6 min (SD=32.3) in PRS and PRSL, respectively ( p=0.002, unpaired t test). There was no significant difference between the two groups in terms of hospital stay, morbidity or mortality. Recurrence rates and mean time interval to recurrence were, respectively, 20.6% and 45.5 months in PRS compared to 7.7% and 13.3 months in PRSL ( p=0.049, chi-square test; p=0.001, unpaired t test). Both groups had significant improvements in postoperative incontinence score ( p<0.0001, Wilcoxon's matched-pairs signed-ranks test), however, there were no significant changes in anorectal manometric findings and pudendal nerve terminal motor latency assessment. CONCLUSIONS: Perineal rectosigmoidectomy with levatorplasty is associated with a lower recurrence rate and a longer time to recurrence than perineal rectosigmoidectomy alone. Levatorplasty should be offered to patients when a perineal approach for rectal prolapse is selected.

Adult↗

PubMed2004

Paraganglioma of the ampulla of Vater: a potentially malignant neoplasm.

Paragangliomas are rare tumours originating from neuroectodermic remnants and are usually considered as benign. We present two cases of paraganglioma of the ampulla of Vater that were treated surgically by pancreaticoduodenectomy. In one case, histopathology revealed malignant characteristics of the tumour with invasion of the pancreas and simultaneous duodenal lymph-node metastases. Both patients had a favourable outcome without disease recurrence at 40 and 44 months postoperatively. Only 21 cases of ampullary paraganglioma have been reported in the literature, 7 of them with malignant characteristics. In conclusion, paragangliomas of the ampulla of Vater have malignant potential. Surgical therapy of these tumours should not be limited to local resection, as disease recurrence and lymph node involvement have been reported. We propose that paragangliomas of the ampulla of Vater should be operated by cephalic pancreaticoduodenectomy, which allows long-term and disease-free survival.

Adult↗

PubMed2004

The effect of diverticular disease on the colonic J pouch.

OBJECTIVE: The aim of this study was to assess the impact of the diverticular disease (DD) on function and on postoperative complications of the colonic J-pouch (CJP) with pouch-anal anastomosis. METHODS: Patients who underwent a CJP between December 1990 and August 2001, were retrospectively reviewed. The presence of DD in the CJP was assessed on pouchogram prior to ileostomy closure. A questionnaire designed to evaluate the degree of continence (total incontinence score (IS): 0 = worst, 20 = best) and pouch evacuation (total evacuation score (ES): 0 = worst, 28 = best) was used for comparison between patients with DD and those without DD (NDD). RESULTS: Sixty-six patients (47 males; 19 females) with a median age of 68 years (range 28-87 years) were included. The median follow-up period was 22 months (range 2-106 months). Twenty-four patients comprised the DD group and 42 were in the NDD group. The two groups were comparable for age, gender and time from ileostomy closure; all patients with postoperative chemoradiation therapy were in the NDD group. The total ES and IS total did not significantly differ between the two groups with a P-value of 0.11 and 0.09 respectively. Furthermore, there was no significant difference in the total incidence of pouch complications between the two groups (3 strictures, 1 leak, 1 fistula in the NDD group vs. 1 pelvic sepsis in the DD group; P = 0.4). CONCLUSIONS: The presence of DD in a CJP does not seem to impact pouch function or the postoperative complication rate.

Aged↗

PubMed2004

Is routine pouchogram prior to ileostomy closure in colonic J-pouch really necessary?

INTRODUCTION: Colonic J-pouch with coloanal anastomosis has gained popularity in the surgical treatment of middle and lower rectal pathologies. If a diverting ileostomy is performed, a pouchogram is frequently performed prior to ileostomy closure. The aim of this study was to assess the routine use of pouchogram prior to ileostomy closure in patients with colonic J pouch-anal anastomosis. METHODS: All patients who underwent a colonic J pouch-anal anastomosis between 1990 and 2000 were retrospectively reviewed. Patients with temporary loop ileostomy who had pouchogram prior to ileostomy closure were included. Pouchogram results were compared to the patient's post ileostomy closure clinical outcome. Sensitivity, specificity and predictive values of pouchogram were assessed. RESULTS: Eighty-four patients had a pouchogram prior to ileostomy closure. Radiological abnormalities were evident in 6 patients, including 4 strictures, 1 pouch-vaginal fistula and 1 leak. Of these findings, 4 were false positives (3 strictures and 1 leak) and two were true positives (1 stricture and 1 pouch-vaginal fistula). The actual rate of pouch complications was 9.5% (8 complications) including 3 anastomotic leaks, all with normal pouchogram, 3 strictures requiring dilatation under anaesthesia, only one detected by pouchogram, and 2 pouch-vaginal fistulas, only one diagnosed by pouchogram. The sensitivity and specificity of pouchogram, respectively, was 0 and 98% for anastomotic leak, 33 and 96% for stricture, and 50 and 100% for pouch-vaginal fistula. Overall, pouchogram changed the management in only 1 of 84 patients. CONCLUSION: Pouchogram has a low sensitivity in predicting complications following ileostomy closure in patients after colonic J-pouch anal anastomosis and rarely changes the management of these patients. The use of pouchogram prior to ileostomy closure may be unnecessary and should be reserved in cases of clinical suspicion of complications.

Adult↗

PubMed2004

[Laparoscopic treatment for Crohn's disease].

AIM: Several studies have demonstrated the feasibility and safety of laparoscopic surgery for Crohn's disease. A trend towards less morbidity as compared to laparotomy has been suggested. However, problems noted early in the experience may have prevented the optimal benefit from having been conferred. Accordingly, the aim of this study was to evaluate perioperatively those patients. METHODS: All 51 patients with Crohn's disease who underwent an intestinal resection at Cleveland Clinic Florida between January 1997 and December 1998 were analyzed. RESULTS: Seventeen patients underwent laparoscopic treatment: there were no significant differences between the 2 groups as to age, gender, incidences of comorbidity, prior laparotomy, or the use of anti-inflammatory and immunosuppressive agents. Similarly, there were no significant differences between the 2 groups as to either surgical indication, intraoperative findings, or procedure performed. Moreover, there were no significant differences concerning total anesthetic time or surgical operative time, the incidence of intraoperative morbidity or need for enterolysis or stoma construction, use of intraoperative endoscopy, or need for transfusion. Significant differences were noted in the duration of patient controlled analgesic usage (3.1 days in the laparoscopic group vs 3.9 days, respectively; p = 0.03), the incidence of postoperative morbidity (7/17 patients in the laparoscopic group vs 27/34 patients: p = 0.01), and length of hospital stay (6.4 days in the laparoscopic group vs 9.6 days, respectively; p = 0.05). CONCLUSIONS: In this retrospective cohort comparative study, laparoscopic intestinal resection for Crohn's disease, when compared to laparotomy, was associated with a short duration of patient controlled analgesic usage, a lower incidence of postoperative morbidity and a shorter hospital stay, without significantly increased operative time.

Adult↗

PubMed2003

A tale of two colons and two cancers. Distinct carcinogenesis and clinical outcome according to location proximal or distal to the splenic flexure.

The central hypothesis explored in this paper is that colorectal cancer (CRC) is a heterogeneous disease. The initial clue to this heterogeneity was provided by genetic findings; however, embryological and physiological data had previously been gathered, showing that proximal (in relation to the splenic flexure) and distal parts of the colon represent distinct entities. Molecular biologists have identified two distinct pathways, microsatellite instability (MSI) and chromosomal instability (CIN), which are involved in CRC progression. In summary, there may be not one, but two colons and two types of colorectal carcinogenesis, with distinct clinical outcome. The implications for the clinicians are two-folds; 1) tumors originating from the proximal colon have a better prognosis due to a high percentage of MSI-positive lesions; and 2) location of the neoplasm in reference to the splenic flexure should be documented before group stratification in future trials of adjuvant chemotherapy in patients with stage II and III colon cancer.

Cell Transformation, Neoplastic↗

PubMed2003

Long-term expression of fibrogenic cytokines in radiation-induced damage to the internal anal sphincter.

BACKGROUND: There is accumulating evidence, both quantitative and qualitative, that pelvic irradiation affects anorectal function. However, the molecular mechanisms responsible for radiation-induced damage to the anal sphincter remain unclear. AIM: To determine the expression of transforming growth factor-beta 1 (TGF-beta 1) and its downstream effector connective tissue growth factor (CTGF) in the anal sphincter of a patient irradiated for prostate cancer. PATIENT: A 82 year-old patient developed a rectal adenocarcinoma and underwent an abdomino-perineal resection (APR), four years after receiving pelvic irradiation for prostate carcinoma. METHODS: Tissue sections of the anal sphincter were processed for histology. Immunostaining for TGF-beta 1 and CTGF were performed. RESULTS: CTGF and TGF-beta 1 immunoreactivity was detected in the irradiated anal sphincter, and was absent in controls. Immunoreactivity for both cytokines predominated in the internal sphincter. CTGF and TGF-beta 1 were preferentially detected in endothelial cells, myofibroblasts and fibroblasts; in addition, there was strong immunoreactivity for TGF-beta 1, but not for CTGF in smooth muscle cells of the anal canal. CONCLUSION: Four years after pelvic irradiation, radiation-induced damage appeared to affect predominantly the smooth muscle layer of the anal canal. The molecular mechanisms responsible for radiation-induced fibrosis to these tissues involve prolonged activation of TGF-beta 1 and its downstream effector CTGF.

Adenocarcinoma↗

PubMed2001

Trocar site recurrence in laparoscopic surgery for colorectal cancer.

BACKGROUND: Laparoscopic colorectal surgery has been associated with less postoperative pain, an early return of bowel function, a shorter period of hospitalization and disability, and better cosmetic results. However, the application of laparoscopic techniques to the curative resection of colorectal cancer is still controversial, owing to reports of cancer recurrence at the port site wounds. The accumulation of numerous such reports in a relatively short period raised concern that there might be an extraordinary high rate of port site metastases after laparoscopic colorectal surgery. This concern has led to intense clinical and basic research aimed at determining the incidence and causes of wound recurrence and developing preventative measures to address this problem. Despite these efforts, it is still not clear whether port site metastasis is really an inherent drawback to laparoscopic cancer surgery. METHODS: In this review of the literature on port site metastasis, we gathered data from clinical series of laparoscopic surgery for colorectal cancer. We eliminated series of <50 patients, since they may be flawed by the learning curve required for this technically demanding procedure. RESULTS: The rate of port site recurrences in the 1737 patients who participated in these series was 1%. Although the methods and criteria for patient selection in these studies varied, this figure appears to be comparable to the incidence reported for other malignancies and for laparotomies performed to treat colorectal cancer. CONCLUSION: This review suggests that wound recurrence may actually be the result of an unfortunate learning curve, rather than an inherent concern. However, we must await the final results of large randomized studies before drawing any definitive conclusions.

Adenocarcinoma↗