Radiofrequency ablation is useful for selected cases of pelvic recurrence of rectal carcinoma.

BACKGROUND: We evaluated radiofrequency ablation (RFA) as a new local treatment for pelvic recurrence of rectal carcinoma. METHODS: Fourteen lesions in 10 patients were treated by RFA. Four patients with a solitary recurrent tumor were treated curatively, while 10 lesions in the remaining 6 patients with distant metastases were treated palliatively mainly to control pain. RFA was performed under CT guidance and epidural anesthesia. It was carried out by a single insertion for tumors 3 cm or less in diameter or by multiple insertions for tumors greater than 3 cm. Ablation effectiveness was evaluated by magnetic resonance imaging. For palliative cases, severity of pain was assessed using a visual analogue scale. RESULTS: Needle placement and ablation were accomplished in all 14 lesions. Complications following RFA consisted of 2 cases of abscess formation, 2 cases of neuralgia and one case of bleeding. To obtain complete necrosis, the tumor should be under 4 cm in diameter and not involve any major iliac vessels. Three of 4 patients treated curatively met these conditions. Among these 4 patients, only one recurrence was observed after RFA (follow-up, 6-36 months). Five of 6 patients treated palliatively had tumours greater than 4 cm in diameter or involving iliac vessels. In none of the patients did we achieve complete necrosis and satisfactory analgesia. CONCLUSION: Although certain conditions must be met, RFA is a feasible and effective treatment, and it should be considered as one of the treatment options for pelvic recurrence of rectal carcinoma.

Experience with radiofrequency ablation in the treatment of pelvic recurrence in rectal cancer: report of two cases.

PURPOSE: The aim of this study was to assess the efficacy of radiofrequency ablation in the treatment of pelvic recurrent rectal cancer. METHODS: Computed tomography-guided percutaneous radiofrequency ablation was performed by placing a LeVeen needle electrode into the tumor. Radiofrequency ablation was performed on three lesions in two patients with pelvic recurrent rectal cancer, where the tumors were unresectable and associated with poorly controllable pain despite local treatment consisting of chemoradiotherapy. RESULTS: There were no major complications during the radiofrequency ablation procedure, although one patient complained of a sensation of warmth in the pelvic region, which was reasonably tolerated. Case 1: Each of two lesions of pelvic recurrence, 3 or 4 cm in diameter, was treated once by radiofrequency ablation with placement of a needle electrode into the tumor mass. After the procedure, magnetic resonance imaging confirmed nearly complete necrosis of the tumors, and there was a sufficient relief of pain enabling discontinuation of an opioid. Serum carcinoembryonic antigen returned to normal and there was no evidence of relapse six months after the treatment. Case 2: Radiofrequency ablation was performed by placing a needle electrode at two sites of a recurrent tumor 6 cm in diameter. Postradiofrequency ablation imaging showed viable tissue remnants along the tumor margin, but the treatment produced relief of pain. The procedure was effective in opioid dosage reduction and pain control within a limited time span. CONCLUSION: Radiofrequency ablation is a relatively readily maneuverable and safe local treatment for pelvic recurrence in rectal cancer and is considered a procedure worth applying with further accumulation of experience in clinical cases.

Enhanced detection of deleterious and other germline mutations of hMSH2 and hMLH1 in Japanese hereditary nonpolyposis colorectal cancer kindreds.

Hereditary nonpolyposis colorectal cancer (HNPCC) is an autosomal, dominantly inherited cancer-prone syndrome. Here, we describe a novel and efficient approach for screening mutations of two major HNPCC susceptibility genes, hMSH2 and hMLH1. The system consists of RNA extraction from whole blood treated with the translation inhibitor, followed by long RT-PCR of the entire coding regions combined with direct sequencing. In analysis of 15 kindreds suspicious for HNPCC, 8 samples were subjected to analysis after puromycin treatment and 7 samples were analyzed without puromycin treatment. Three deleterious mutations were detected in the kindreds with puromycin treatment, while none were observed in those without puromycin. Signals from mutated alleles were enhanced after puromycin treatment and easily distinguished from the wild-type allele, achieved by suppression of nonsense-mediated mRNA decay. Furthermore, 12 other mutations were detected in 15 kindreds. The system is considered to be a reliable and useful approach for detecting germline mutations of hMSH2 and hMLH1 in HNPCC kindreds.