Lasers and colon polyps. Technology and pathology: the courtship continues

Lasers in rectosigmoid tumors

Over a 14-year period, 746 patients were treated at the Lille Laser Center for rectosigmoid tumor. Two hundred seventy-two patients were treated for palliation of symptoms from rectosigmoid cancer and 474 patients were treated for a benign rectosigmoid villous adenoma. The immediate success rate and complication rate were 85% and 2%, respectively, for patients with advanced cancer, and 92.8% and 1.8% for those with a villous adenoma. Patients with an advanced cancer remained functionally improved during a 10.1-month average period after initial improvement. The recurrence rate after initial treatment for villous adenomas was 18% during a 29.7-month average follow-up. Immediate results were influenced by reason for treatment, initial symptoms, and circumferential extension for patients with a cancer, and only by circumferential extension for patients with a villous adenoma. Long-term results were influenced by reason for treatment and circumferential extension for patients with cancer, and by reason for treatment, initial histology and localization for patients with a villous adenoma. Laser treatment provided relief of symptoms in inoperable patients with advanced rectosigmoid carcinomas. Because treatment is long and difficult and the cancer rate is high, endoscopic laser should be limited in patients with a circumferential villous adenoma to non-surgical candidates. The risk of complication after surgery (some being fatal) has to be balanced against the risk of undetected carcinoma and the indication for endoscopic laser treatment should be discussed case by case.

The potential and limitations of laser photoablation of colorectal adenomas

Ablation of colorectal adenomas by Nd:YAG laser energy was investigated in 271 patients. Two hundred and forty-one patients, selected because of poor surgical and medical condition or refusal of surgery, presented with incompletely removed polyps or with lesions unsuitable for endoscopic polypectomy. Thirty patients with polyposis coli were treated for rectal stump polyps after subtotal colectomy and ileorectal anastomosis. Because of insufficient follow-up (28) or malignant degeneration (23), full evaluation was possible in 196 colon adenoma and 24 polyposis patients. Complete ablation with histologic confirmation for at least 12 weeks was achieved in 150 (82%) of the 183 colon adenomas. This declined to 141 (77%) because of later recurrences in prolonged follow-up. Treatment of large adenomas was less successful than that of intermediate and small lesions: ultimate ablation in 56, 85, and 93%, respectively. Impressive was the immediate relief in 100 symptomatic elderly patients, who were bothered by frequent diarrhea, excessive mucous discharge, and incontinence. All patients survived despite major complications (7%) that mainly consisted of stenosis and hemorrhage. Rectal stump polyps were eliminated in 20 patients with polyposis coli. The remaining four had an uneventful ileoanal anastomosis for ultimately uncontrollable growth of polyps. Malignancy was discovered in 22 adenoma patients and in 1 polyposis patient. We recommend laser ablation of colorectal adenomas for small and medium-sized polyps, that cannot be removed by endoscopic polypectomy in inoperable patients or in patients refusing operation. Laser treatment for extensive adenomas seems only appropriate for symptomatic relief.

Endoscopic laser treatment for rectosigmoid villous adenoma: factors affecting the results

Endoscopic laser treatment is reported in 264 patients with benign rectosigmoid villous adenomas revealed by biopsy. Patients include 100 who had contraindications to surgery, 60 who had a tumor recurrence after a nonlaser treatment, 101 for whom surgical resection appeared to be too drastic for a tumor found benign on biopsy, and 3 who refused surgery. Two types of lasers were used: the Nd:YAG and the argon laser. In some patients, both lasers were used. Treatment was completed in 226 patients. Total tumor destruction was attained in 92% of them, a carcinoma was detected in 7% on biopsy specimens obtained during laser treatment, and benign villous tissue persisted in 1%. During the average 25.9-mo follow-up period of the patients with total tumor destruction, 13% had a tumor recurrence. Treatment was well-tolerated with no major complications. The circumferential extension of the tumor base was the only factor affecting the duration of treatment, and the rate of complications. The recurrence rate after initial treatment was higher in patients treated for a recurrence after a previous nonlaser treatment than in patients treated only by laser (p = 0.04). It was also higher when the initial histology was low-grade dysplasia than if it was high-grade dysplasia (p = 0.017) and when the tumor was located in the lower or middle rectum as opposed to the upper rectum or sigmoid (p = 0.04). We estimated that the direct cost of laser treatments was 28%-40% of the surgery charges for lesions of identical size in our hospital and 31%-69% at UCLA Center for the Health Sciences. Because treatment is long and difficult and the cancer rate is high, endoscopic laser for patients with a circumferential villous adenoma should be limited to nonsurgical candidates. The risk of a fatal complication after surgery has to be balanced against the risk of undetected carcinoma in the other patients and the indication for endoscopic laser treatment should be discussed case by case.

Snare cautery debridement prior to Nd:YAG photoablation improves treatment efficiency of broad-based adenomas of the colorectum

Forty-six patients who underwent piecemeal resection of large, sessile villous adenomas followed by immediate laser photoablative therapy are presented. In contrast to previously published series utilizing laser alone, prior snare resection of such lesions provides copious tissue for histologic analysis, decreases the amount of residual neoplasm requiring laser treatment, and has the potential to improve treatment efficacy.

Endoscopic laser therapy for esophageal cancer: present status with emphasis on past and future

Although the major initial application for endoscopic laser therapy was for the management of gastrointestinal hemorrhage, it is now more common to use the laser endoscopically for the treatment of gastrointestinal neoplasms. A major body of literature surrounds the use of endoscopic laser therapy for esophageal cancer. The initial patient evaluation to determine if laser therapy is indicated includes a contrast radiograph, a screening endoscopy, and an imaging study. After these tests have been performed, it can be determined whether endoscopic laser therapy (ELT) is the best of the many endoscopic options. There is some difference of opinion as to the specifics of the treatment technique, and these are described. There is general agreement from reviewing the clinical data that it is possible to open the obstructed lumen in a large majority of cases and that functional success (the ability to achieve technically good results as well as clinical improvement without complications) is also possible in the majority of patients. Despite the information suggesting the benefits of ELT for esophageal cancer, there are both conceptual and technical limitations to the current approach to therapy. These limitations as well as potential future applications are discussed.

Parameters affecting laser palliation in patients with advanced digestive cancers

Ninety-nine nonsurgical patients (group I) with esophagogastric cancer were referred to the laser center for palliation of dysphagia, and another 142 nonsurgical patients (group II) with a rectosigmoid cancer were referred for palliation of abnormal rectal discharge (125 patients) or occlusion (17 patients). The immediate success rate was 83% in group I and 90% in group II. Patients were retreated monthly. The average duration of palliation was 4.3 months +/- 0.5 (+/- standard error) in group I and 9.3 months +/- 0.95 in group II. Complication rate was 4% in group I and 3.4% in group II. Parameters affecting results were found only in group I. Factors that could negatively affect the immediate success rate included annular size of the tumor basis more than two thirds of the circumference, tumor localization at the upper third of the esophagus, and recurrence after a nonlaser treatment. The average duration of improvement after initial success was affected only by the circumferential extension.

Laser surgery in colonic and anorectal lesions

Endoscopic laser therapy for diseases of gastrointestinal tract in general, and lesions of colon, rectum, and anus in particular, is in its infancy. Advances are expected to be made to define those lesions that are amenable to lasers and those that are not. In this process, it is hoped that the relative merits and demerits of the various modes of endoscopic therapy might be brought to light. With the advent of contact Nd:YAG laser technology, it is increasingly realized that such a mode of operation could be used to great advantage in both endoscopic and open surgery related to lower-gastrointestinal tract diseases. Furthermore, contact Nd:YAG laser therapy definitely appears to be efficient and safe and compares favorably with other therapies available. How such an effective modality should be sequenced in combination with other available therapies has yet to be worked out. There is more to be done in this arena, which holds high promises.

Small colonic adenomas with adenocarcinoma. A retrospective analysis

The purpose of this study is to alert colonoscopists to a relatively high incidence of small colonic adenomas with invasive adenocarcinoma among a group of colonic adenomas with invasive adenocarcinoma removed colonoscopically. Retrospective analysis (1973 to 1983) documented nine such lesions that were 1 cm or smaller, representing 15 percent of all colonic adenomas with invasive adenocarcinoma removed during that period. These lesions had no distinctive gross features and could be easily confused with hyperplastic polyps. It is recommended that all colonic polyps be removed at colonoscopy regardless of their size, because even lesions 1 cm and smaller, with "benign" gross appearance, may harbor invasive adenocarcinoma.