17TH ANNUAL SURGICAL UPDATE - RECTAL CANCER
VANCOUVER DECEMBER 2, 2000
Robert Taylor, Vancouver; Doug Wong, New York
Selected cases of early rectal cancer can be treated by local excision. Experience in British Columbia has shown that local excision of cases of early rectal cancer
that have no adverse features, when combined with adjuvant radiotherapy, have local recurrence rates and recurrence-free survival rates similar to those obtained by
standard radical resection.
An increasing body of literature puts forward the use of local excision, with or without adjuvant radiotherapy, for selected tumours of early low rectal cancer.
Criteria for selection vary from study to study but include some or all of: TI or T2 lesions, well or moderately-well differentiated, no lymphatic or vascular
invasion, no mucoid componer and histologically clear resection margins at excision. Tumours that fall outside these criteria would be considered to have adverse
features. Reported recurrence rates, with varying criteria of selectivity, range from 1% to 15% for T 1 tumours treated by local excision alone and from 0 to 6% if
treated with local excision combined with adjuvant radiotherapy. For T2 tumours, rates, again with varying selection criteria, range from
~ 10% to >40% treated by local excision alone and from 7% to 14% if treated by local excision combined with adjuvant radiotherapy. For TI and T2 lesions without
adverse features the 5-yr recurrence-free survival is in the order of 85%, with or without radiotherapy. In the presence of adverse features adjuvant radiotherapy
significantly improves the 5-year survival.
Preoperative staging of the primary tumour is of key importance for decision making. Digital rectal exam is reported to be from 65% to 80% accurate in determining T stage,
particularly in distinguishing between T2 and T3 tumours. Endorectal ultrasound can increase this accuracy to >95% and therefore should be part of the workup.
The transanal approach is the operative procedure most commonly used. Tumour features that influence the ability to successfully excise it include: tumour size, its
location on the circumference of the rectum, and its distance from the anus. The procedure can be difficult and the surgeon should be familiar with techniques that help,
and pitfalls that frustrate, successful excision.
Close post-operative-follow-up to detect local recurrence is always indicated because salvage procedures with curative intent are often possible in these cases treated
initially by local excision. Successful salvage (abdominoperineal resection or repeat local excision) with long term disease-free survival has been obtained in 30% of
the local recurrences of such cases in the British Columbia experience. The literature reports successful salvage in 25% to 75%.
Taylor, Wong
References
Taylor RH, Hay JH, Larsson SN. Transanallocal excision for selected low rectal cancers. Am J Surg 1998 May; 175(5):360-363.
Le Voyer TE, et al. Local excision and chemoradiation for low rectal T1 and T2 cancers is an effective treatment. Am Surg 1999 July; 65:625-631.
Chakravarti A, et al. Long term follow-up of patients with rectal cancer managed by local excision with and without adjuvant irradiation. Ann Surg 1999 July; 230(1):49-54.
Mellgren A, et al. Is local excision adequate therapy for early cancer? Dis Colon Rectum 2000 Aug; 43(8): 1064-1074.
Bailey HR, et al. Local excision of carcinoma of the rectum for cure. SURGERY 1992 May; 111(5):555-561.
Bleday R, et al. Prospective evaluation oflocal excision for small rectal cancers. Dis Colon Rectum 1997 Apr; 40(4):388-392.
Willet CG, et al. Selection factors for local excision or abdominoperineal resection of early stage rectal cancer. CANCER 1994 June; 73(11):2716-2720.
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