Terry Phang
Points of Emphasis
- BC Cancer Agency Guidelines - BCCA Rectal Cancer Group
- 1996 review of appropriateness of staging investigations, adjuvant therapy, hospital and surgeon experience, outcomes
- Discussion of education and organization strategies
BC Cancer Agency Guidelines for Management of Rectal Cancer
BCCA Rectal Cancer Group - P Terry Phang, Greg McGregor, John Hay, John MacFarlane, Rona Cheifetz, Andy Coldman, Noelle Davis, Robert Taylor, Barry Sullivan,
Roy Ma, Amil Shah, Caroline Speers, Janet Pitt, Andy Coldman
1.a. Preoperative staging
Once histologic diagnosis and location of the rectal cancer have been established, appropriate management of rectal cancer depends upon accurate preoperative staging.
The extent of local disease should be assessed by digital rectal examination and one of endorectal ultrasound, CT scan, or MRI in order to provide essential information
about the extent of local invasion and the likelihood of positive mesorectal nodes.
Examination of the entire colon is needed to exclude synchronous cancers or polyps. A metastatic survey should include chest x-ray and abdominal ultrasound or CT scan.
1.b. Surgical management by preoperative stage
Surgical management may include segmental resection techniques or local excison. Segmental resection techniques include anterior resection, low anterior resection,
abdomino-perineal resection, and Hartmann resection. [See special considerations - surgical techniques according to height from anal sphincter, 9.1.c]
Clinical stage 1 [T1, T2, N0, M0]
These tumors are managed by segmental resection. Preoperative radiation is not indicated. Local excison may be considered for favorable lesions. The usual criteria for
favorable lesions are well or moderate differentiation, size < 3 cm, and absence of lymphatic or vascular invasion. Postoperative radio therapy is usually indicated
after local excison has been carried out.
Clinical stage 2 [T3, T4, N0, M0]
Where full thickness penetration of the rectal wall is suspected, preoperative short course radiotherapy is indicated. This regimen consists of five daily fractions of
500 cGy with the surgery to follow within ten days. Local excison is contra indicated. This course of radiotherapy confers the same benefit as radical postoperative
radiation without less side effects.
If the tumor has characteristics which suggest the possibility of fixation or invasion of surrounding structures, preoperative radical radiotherapy and chemotherapy may
be indicated. This regimen is usually given over five weeks with surgery to follow six weeks after completion of therapy.
Stage 2 tumors recognized postoperatively should be referred for combined adjuvant treatment if none was given preoperatively. If short course radiotherapy was utilized
preoperatively, chemotherapy should be considered postoperatively.
Clinical stage 3 [any T, N1, N2, N3, M0]
These lesions are managed as for those in stage 2.
Clinical stage 4 [any T, any N, M1]
In spite of the presence of metastases, excison of the primary tumor may still provide the best form of palliation. In appropriate circumstances, operation may be
facilitated by chemotherapy and radiation. The occasional patient with an isolated liver or lung metastasis may benefit from resection of the metastatic lesion.
Other local measures such as fulguration, endoluminal radiation, and internal stent placement may be of benefit. These local measures may also be helpful in managing
patients who are unfit for surgery.
1.c. Special considerations - Surgical techniques according to height from anal sphincter
Sphincter-sparing resection should be considered for rectal cancer more than 4 cm above the anal sphincter. Ability to perform sphincter-sparing resection and
reconstruction using techniques for coloanal anastomosis for distal-third rectal cancers will depend on body habitus, tumour size, and comorbid medical status.
Suggested surgical techniques for rectal cancer resection according to the distance of the lower end of tumor from the anal sphincter are described in the following
sections.
1.c.i. Tumour more than 10 cm from the anal sphincter
The technique of anterior resection for upper-third rectal cancer should include the following points: distal resection margin 5 cm from distal edge of tumour,
subtotal mesorectal excison with distal mesorectal margin at least 5 cm from the distal edge of the tumor, sparing the nervi erigentes where possible, en bloc
resection of adjacent organs infiltrated by rectal tumour for curative resection, and a long-tie on the superior rectal or inferior mesenteric artery marking the
apex of the mesenteric resection.
1.c.ii. Tumour less than 10 cm from, but above the anal sphincter
The technique of low anterior resection for mid- and distal-third rectal cancer should include the following points: resection of entire rectum with at least 1 cm
negative macroscopic distal margin, resection of entire mesorectum to top of anal sphincter and pelvic floor, sparing the nervi erigentes where possible, en bloc
resection of adjacent organs infiltrated by rectal tumour for curative resection, and a long-tie on the superior rectal or inferior mesenteric artery marking the
apex of the mesenteric resection.
Although a 2 cm distal margin is preferable, a distal margin of 1 cm for mid- and distal-third rectal cancer is acceptable because longitudinal mural extension of
tumor is rarely more than 1 cm (1,2). It is known that lymph nodes may be present in the mesorectum both proximal and distal to the tumour. A 5 cm distal margin for
proximal lesions is recommended to assure that all lymph nodes in the area of the tumor will be removed when less than total mesorectal excison is performed. Mid- and
distal-third rectal cancer resection should include the entire mesorectum to remove all perirectal lymph nodes.
Although preoperative radiation can decrease the gross size of the cancer, residual tumour may be present in the submucosa distal to the shrunken mucosal margin of the
tumour. Therefore, the distal resection margin for radiated cancers should be more than 1 cm and should be guided by the location of the distal tumour margin before
radiation in order to assure a clear distal resection margin.
1.c.iii. Tumour near or at the anal sphincter
The technique of abdominoperineal resection for rectal cancer near or at the anal sphincter should include the following points: resection of the entire rectum and anal
sphincter with wide ischiorectal margins, resection of entire mesorectum to top of anal sphincter and pelvic floor, sparing the nervi erigentes where possible, en bloc
resection of adjacent organs infiltrated by rectal tumour for curative resection, and a long-tie on the superior rectal or inferior mesenteric artery marking the apex
of the mesenteric resection.
1.d. Pathology reporting
The preliminary report will consist of examination of the unfixed specimen by both surgeon and pathologist at the time of surgery; preferrably intraoperatively with direct
communication between surgeon and pathologist. Proximal and distal resection margins should be noted. Location of the tumour relative to the peritoneal reflection should
be noted. The apex of the mesenteric resection at the proximal tie marking the superior rectal or inferior mesenteric artery should be identified and the presence or
absence of gross lymphadenopathy should be noted. The specimen should be marked to allow histologic examination of the radial circumferential margin. The closest radial
margin should be noted and marked; the closest radial margin should be oriented as to anterior, posterior, left and right.
The histologic report will consist of examination of the fixed specimen to include reporting of the cell type and degree of differentiation, the maximal depth of
penetration of the tumour, the proximal and distal margins, the circumferential margins including distance to the nearest radial margin, involvement of lymphatics and
blood vessels at the proximal, distal, and apical mesenteric margins, and examination and reporting on at least 12 lymph nodes as recommended by TMN [UICC] and AJCC (3).
Consideration should also be made of reporting the closest radial margin of lymph node metastasis to the edge of the mesorectal fascial envelope (4).
1.e. Final stage assignment
The surgeon and pathologist should agree on the likelihood of the presence or absence of pelvic residual disease based on gross and histologic examination of the proximal,
distal and radial resection margins. The surgeon should assign the postoperative pathologic stage in consideration of findings from metatstatic investigation, laparotomy,
and pathology reporting.
References
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