Planes of sharp pelvic dissection for primary, locally advanced, or recurrent rectal cancer.

In the design of operations for rectal cancers, the focus is often on circumventing the local extent of disease and leaving the pelvis free of cancer. The local extent of disease may range from minimal intramural invasion to the direct extension of a primary tumor to pelvic sidewall structures, e.g.

Total mesorectal excision with autonomic nerve preservation: a new foundation for the evaluation of multi-disciplinary adjuvant therapy in the management of rectal cancers.

Local and distant recurrence rates and disease-free and overall survival are markedly improved by total mesorectal excision, with little increase in morbidity, compared with other techniques of resection of rectal cancer. Adjuvant therapy is associated with significant morbidity and initial results suggest it may not be beneficial in the aggregate. Adjuvant therapy must be re-evaluated in trials using TME as standard operative technique.

The role of p53, p21WAF1/C1PI, and bcl-2 in radioresistant colorectal carcinoma.

Genetic alterations in the p53 tumor suppressor gene are common in human colorectal cancers, occurring in approximately 70% of tumors. In vitro studies have shown that wild-type p53 is involved in controlling cell cycle checkpoint functions and apoptosis involved in the cytotoxic response induced by ionizing radiation and several anticancer chemotherapeutic agents. Wild-type p53 protein can transcriptionally activate the WAF gene, which encodes a cyclin-dependent kinase inhibitory protein, p21WAF1/C1PI protein, and transcriptionally repress the bcl-2 gene, which encodes an inhibitor of apoptosis.

Pudendal neuropathy is the only parameter differentiating leakage from solid stool incontinence.

Purpose: Fecal incontinence may occur in several forms. Although some patients are grossly incontinent, other patients experience only leakage. In patients with gross incontinence, severity can range from the mildest forms (limited to loss of control of flatus) to the most severe forms (involving loss of solid stool).

Endoscopic management of malignant colorectal polyps.

Malignant polyps are adenomatous polyps that contain cancerous cells that have penetrated the muscularis mucosae. Pedunculated malignant polyps that have not yet developed to level 4 invasion and have no other adverse histopathologic criteria have a high likelihood of cure by endoscopic excision alone. However, if level 4 invasion has been reached or if any additional adverse characteristic, such as poor differentiation, lymphatic or venous invasion, or close or involved margins, is present, the risk of inadequate treatment from endoscopic excision alone becomes appreciable.