Endoscopic transanal resection for rectal cancer

Local methods of treatment of rectal cancer

Over 11 000 new cases of rectal cancer are reported in the UK each year. Recent technical advances have increased interest in local management of the disease. The introduction of screening for colorectal cancer will potentially lead to an increased number of early rectal cancers suitable for local curative treatment. In addition, as the proportion of elderly patients in the population rises, local methods of treatment of rectal cancer will become increasingly important in this group of patients with comorbid disease. A literature search was performed on Medline database for English language publications on local treatments of rectal carcinoma. Preoperative assessment, selection of patients, local therapeutic and palliative methods of treatment were evaluated. Local methods of treatment can be used for potentially curative operations for rectal cancer. Preoperative endoanal ultrasound appears to be the most useful investigation for determining depth of local invasion. Transanal endoscopic microsurgery has extended the boundaries of local surgery and permits access to the mid and upper rectum with results similar to those of conventional local techniques. Laser therapy and transanal resection provide the best form of palliation for more advanced rectal carcinomas.

Transanal endoscopic treatment of benign canine rectal tumours: preliminary results in six cases (1992 to 1996)

Transanal endoscopic resection and cautery of benign rectal tumours was performed in six dogs with extensive and/or inaccessible rectal neoplasia. The results were encouraging, with three dogs cured and the quality of life of a further two improved for a significant time. The remaining dog died as a result of rectal perforation. Transanal endoscopic treatment of extensive and/or inaccessible benign canine rectal tumours offers an alternative to more radical techniques such as pull-through surgery.

The value of the preoperative mucosal biopsy in the diagnosis of colorectal mucinous adenocarcinoma

BACKGROUND

As a rule, mucinous colorectal adenocarcinomas tend to be at a more advanced stage at the time of discovery than their nonmucinous counterparts. This study assesses the potential value of the preoperative biopsy in the diagnosis of such mucinous adenocarcinomas.

METHODS

The preoperative biopsy specimens and the corresponding resection specimens of 189 patients with colorectal carcinomas were examined and compared by conventional light microscopic study. The stage of the tumor, using the modified Dukes classification of Astler and Coller, was correlated with the percentage of mucinous component (MC) in the resection specimens. The MC in the preoperative biopsy was assessed by the presence of: (1) malignant-appearing glands disrupted by the presence of abundant extruded intraluminal mucin; (2) pools of mucin in the connective stroma of the adenocarcinoma; and (3) superficial pools of mucin containing ribbons or clusters of neoplastic epithelial cells.

RESULTS

The presence of a significant (more than 25%) MC in the resection specimen correlated well with an advanced stage of the tumor; 82% of tumors with more than 25% MC were at the B2 or higher stage, compared with 64% of tumors with less than 25% MC (P < 0.05). Finding MC in the preoperative biopsy correlated well with a similar finding in the resection specimen and with a B2 or higher stage of the tumor in such specimens; 83% of MC-positive biopsy specimens exhibited more than 25% MC in the corresponding resection specimen, whereas only 10% of MC-negative biopsy specimens were associated with a surgical specimen containing more than 25% MC (P < 0.001). Similarly, 83% of such MC-positive biopsy specimens revealed a carcinoma at the B2 or higher stage upon resection, compared with 63% of the MC-negative biopsy specimens (P < 0.02).

CONCLUSIONS

Colorectal adenocarcinomas showing MC in the preoperative biopsy are significantly more likely to reveal a high mucin content and to be at an advanced stage at resection. Thus, such preoperative findings should be recorded and made available on a prospective basis to the treating physicians.