Comparison of open and laparoscopic secure placement of peritoneal dialysis catheters.

BACKGROUND: A major and frustrating complication of peritoneal dialysis catheter placement is mechanical outflow obstruction, which may be caused by catheter tip migration. Therefore, a secure and correct positioning of the catheter is important to minimize this risk. This technique is easily accomplished by a laparoscopic approach. METHODS: The outcomes of 50 patients in whom peritoneal dialysis catheters were inserted laparoscopically with a secure catheter placement technique were compared with those of 52 patients who underwent an open surgical technique using a stiff wire as guidance for the catheter. The data were prospectively collected but not randomized. All the patients had virgin abdomens, and all the procedures were undertaken or supervised by one surgeon. RESULTS: Catheter migration occurred in six patients (12%) in the open group, as compared with none in the laparoscopic group (p = 0.027). There were no significant differences in catheter survival between the two groups. CONCLUSIONS: The laparoscopic technique with secure placement of the catheter lowered the incidence of catheter migration, but did not increase the catheter survival.

p53 gene mutation, microsatellite instability and adjuvant chemotherapy: impact on survival of 388 patients with Dukes' C colon carcinoma.

Two common genetic alterations in colon carcinoma, p53 mutation and microsatellite instability (MSI), were investigated to determine their prognostic importance for cancer-specific survival and response to adjuvant chemotherapy in patients with Dukes' C colon cancer. The p53 tumour suppressor gene encodes for a nuclear phosphoprotein involved in cellular response to DNA damage, while MSI is a characteristic feature of tumours with defective DNA mismatch repair. The cellular response mechanisms to DNA-damaging agents in tumours with mutant p53 or MSI may as a consequence differ, and this might translate into different outcomes following adjuvant chemotherapy. A consecutive series of 388 Dukes' C colon carcinomas with 5-year median follow-up was analysed for p53 mutation and for MSI (in proximal/transverse carcinomas only) using polymerase chain reaction single-strand conformation polymorphism. The incidence of p53 mutation was 28% in all carcinomas while that of MSI in proximal/transverse carcinomas was 19%. One hundred and thirty-three patients (34%) received adjuvant chemotherapy (5-fluorouracil/levamisole) with curative intent. The presence of p53 mutation did not predict for survival in either the treated or untreated groups. The presence of MSI in the proximal/transverse colon carcinoma group was associated with significantly better 5-year survival: 58 versus 32% (p = 0.015, log rank test). This was largely due to better survival observed in the MSI subgroup that received adjuvant chemotherapy (p = 0.017, log rank test). Further work in prospective, randomised clinical trials investigating the effects of adjuvant therapy should consider incorporating MSI status in order to determine whether this is an independent predictive factor for survival and/or response to adjuvant chemotherapy.

P53 alterations have no prognostic or predictive significance in Dukes' C rectal carcinomas.

We investigated the prognostic significance of p53 alterations in a consecutive series of 122 Dukes' C rectal carcinomas with a median patient follow-up period of 56 months. One third of patients were treated with post-operative adjuvant chemotherapy. Overexpression of p53 protein was observed in 42% (50/118) of cases using immunohistochemical analysis and mutation of the p53 gene in 38% (47/122) using single strand conformation polymorphism technique. Neither p53 overexpression nor mutation were associated with significantly worse patient survival in the overall group or in the subgroup of 35 patients who received standard post-operative chemotherapy with 5-fluorouracil and levamisole. Our results do not support the use of p53 alteration as a clinically useful prognostic marker for the overall survival of rectal cancer patients or for predicting their response to chemotherapy.

TP53 gene mutation status in pretreatment biopsies of oesophageal adenocarcinoma has no prognostic value.

Identification of markers which help to predict response to treatment and overall survival at the time of diagnosis would assist in the management of patients with oesophageal adenocarcinoma. In the present study we investigated the prognostic significance of mutations to the TP53 tumour suppressor gene in a large, consecutive series of oesophageal adenocarcinomas. The incidence of TP53 mutation determined by molecular analysis of endoscopic biopsy specimens was 36% (49/135). No statistically significant difference was observed in patient survival according to the TP53 status of the tumour biopsy. The median survival time for patients with mutation was 12 +/- 1 months compared with 14 +/- 2 months for patients with TP53. These results demonstrate that mutation of the TP53 gene is not a useful predictive marker for patient survival in oesophageal adenocarcinoma.