KCRS update from ASCRS Meeting:
Over 1300 Colon and Rectal surgeons from 48 countries met in early June
to discuss the current and developing diagnostic and treatment options
for colon and rectal cancer, inflammatory bowel disease, and various
benign anorectal problems. This issue will focus on the cancer update.
Later issues will discuss new developments in incontinence and benign
anorectal conditions.
Transrectal excision of low rectal cancer:
Transrectal excision remains a viable option for small, low lying, well
differentiated tumors. If the specimen reveals lymphovascular invasion,
poor differentiation or muscle invasion then chemoradiation or standard
cancer resection (low anterior or abdominoperineal resection depending
on tumor location) is indicated. Despite close follow up local
recurrence after transanal excision may not be respectable later.
Total Mesorectal Excision +/- chemoradiation:
For invasive tumors of the middle and lower rectum the entire lymph
node bearing area (the mesorectum) should be removed. To prevent
unacceptable diarrhea a colonic reservoir usually needs to be
constructed before anastomosis to the anal canal. In recent European
series Total Mesorectal Excision (TME) lowers the local recurrence rate
from 30% to about 10% for T3 or N1, N2 disease. Chemoradiation further
lowers the local recurrence rate to about 1%. Pre-operative
chemoradiation is recommended by most centers.
Complete response to pre-operative chemoradiation:
The increased use of preoperative chemoradiation has resulted in a
group of patients who have no clinically detectable residual cancer:
"Complete Responders". What to do with complete responders is
controversial. A series from Brazil has found up to 30% have no
discernible residual disease but of those 15% died of disease, mostly
distant metastasis. How and when to assess for complete response is
questionable, especially the assessment for residual deep or nodal
disease. Randomized trials are being constructed.
ACOSOG Update
(American College of Surgeons Oncology Group)
Two New Protocols in September 2001: For node (+) colon cancer:
A CEA vaccine using a monoclonal antibody with essentially no toxicity.
Randomized to chemotherapy versus chemotherapy plus vaccine.
For node (-) colon cancer:
A different vaccine- vaccine versus observation.
Upcoming Protocols:
Colon cancer in young patients:
Looks at tumor microsatelite instability and disease free survival.
Anal cancer:
Standard radiotherapy with 5FU + mitomycin versus 5FU + cisplatinum.
Sentinel node evaluation: Does immunohistochemical evaluation of the "sentinel" node improve the predictive power of "node (-)"?
Total mesorectal excision after chemoradiation:
1) What is the optimal timing to resection after chemoradiation for rectal cancer?
2) What is the clinical and prognostic significance of complete response to pre-operative chemoradiation?
When ready for patient enrollment, these protocols will be presented to the Cancer
Committee and the IRB at Harrison Memorial Hospital to be available to our patients.
Remember Medicare will now cover a screening colonoscopy
every ten years for average risk patients
Kitsap ColoRectal Surgery, Johnny B. Green, MD, FACS, FASCRS
Eastwood Building, 2528 Wheaton Way, #103, Bremerton, WA 98310
(360) 377-4717 -- (360) 377-4134 fax
www.kitsapcolorectal.com
