2013+ASCRS实践参数：结直肠癌的治疗（修订版）

535Diseases of the Colon & ReCtum Volume 56: 5 (2013) the american society of Colon and Rectal surgeons is dedicated to ensuring high-quality patient care by advancing the science, prevention, and manage- ment of disorders and diseases of the colon, rectum, and anus. the standards Committee is composed of society members who are chosen because they have demonstrat- ed expertise in the specialty of colon and rectal surgery. this Committee was created to lead international efforts in defining quality care for conditions related to the co- lon, rectum, and anus. this is accompanied by develop- ing Clinical Practice Guidelines based on the best available evidence. these guidelines are inclusive, and not prescrip- tive. their purpose is to provide information on which de- cisions can be made, rather than dictate a specific form of treatment. these guidelines are intended for the use of all practitioners, health care workers, and patients who desire information about the management of the conditions ad- dressed by the topics covered in these guidelines. it should be recognized that these guidelines are not inclusive of all proper methods of care or exclusive of meth- ods of care reasonably directed to obtaining the same re- sults. the ultimate judgment regarding the propriety of any specific procedure must be made by the physician in light of all the circumstances presented by the individual patient. STATEMENT OF THE PROBLEM Colorectal carcinoma remains the second leading cause of cancer related deaths in Western countries with rectal carcinoma accounting for approximately 28% of cases arising from the large bowel. the estimated occurrence of new rectal cancer cases in the united states was projected to be 40,290 in 2012.1 although the trend in incidence of new cases of colorectal carcinoma in the united states has decreased, there has been a significant increase in colorec- tal cancer incidence in economic transitioning countries worldwide.2 there have been significant changes in the manage- ment of rectal cancer over the past 10 to 15 years. a greater understanding of the disease process, more accurate radio- logical staging, multimodality therapeutic intervention, refined surgical techniques, and more detailed histopatho- logical reporting have all contributed to improvements in the management and survival of patients. management has become multidimensional and requires a coordinated effort on the part of physicians and surgeons. it is prefer- able that patients have the opportunity for a multidisci- plinary discussion of their care before embarking on the treatment pathways outlined below. input on the surgical management of rectal cancer should occur before begin- ning any treatment pathway for rectal cancer. METHODOLOGY these guidelines are built on the last set of the american society of Colon and Rectal surgeons Practice Parameters for treatment of rectal carcinoma published in 2005.3 an organized search of meDline, Pubmed, embase, and the Cochrane Database of Collected Reviews was performed through february 2012. Key-word combinations included rectal cancer, total mesorectal excision (tme), radiother- apy, chemotherapy, endorectal ultrasound, magnetic reso- nance imaging (mRi), and enterostomy. Directed searches of the embedded references from the primary articles were also performed in selected circumstances. the final grade of recommendation was performed with the use of the Grades of Recommendation, assessment, Development, and evaluation (GRaDe) system (table 1).4 Defining the Rectum anatomically the rectum is the distal portion of the bowel leading to the anal canal whose upper limit is defined by the end of the sigmoid mesocolon. although this transition is anatomically placed where the taeniae coli splay and are no Practice Parameters for the Management of Rectal Cancer (Revised) J. R. T. Monson, M.D. • M. R. Weiser, M.D. • W. D. Buie, M.D. • G. J. Chang, M.D. J. f. Rafferty, m.D.; Prepared by the standards Practice task force of the american society of Colon and Rectal surgeons Contributing members of the standards Practice task force of the amer- ican society of Colon and Rectal surgeons are listed in the appendix. Dis Colon Rectum 2013; 56: 535–550 Doi: 10.1097/DCR.0b013e31828cb66c © the asCRs 2013 lWW PRACTICE PARAMETERS www.medlive.cn monson et al: PRaCtiCe PaRameteRs foR the manaGement of ReCtal CanCeR (ReViseD)536 longer distinctly identified, the sacral promontory is generally recognized as the transition point from a radiographic perspective. Preoperatively, a tumor whose distal margin is seen approximately 15 cm or less from the anal verge by using a rigid proctoscope should typically be classified as a rectal cancer.5 although this provides a reproducible method for defining the level of the tumor, body habitus and sex must be taken into consideration in the final assessment of location (eg, the rectum is longer in taller patients). PREOPERATIVE ASSESSMENT A. Evaluation and Risk Assessment 1. A thorough disease history should be obtained eliciting disease-specific symptoms, associated symptoms, and family history. Routine laboratory values, including CEA levels should also be evaluated, as indicated. Grade of Recommendation: Strong recommendation based on moderate quality evidence, 1B. history and physical examination remain the cornerstone of the preoperative assessment aiding the clinician in de- termining the necessary preoperative investigations. a cancer-specific history can guide the surgeon to look for associated pathology or metastatic disease and initiate ad- ditional workup. Patients must also be assessed for their fitness to undergo surgery. there are several preoperative cardiac risk assessment systems that can be used to guide surgeons in preoperative management, although a more detailed discussion of perioperative risk stratification is beyond the scope of this guideline.6–8 a complete family medical history should be ob- tained to guide the surgeon to suspect hereditary cancer syndromes and look for associated pathology. Patients meeting clinical criteria for or having a family history of an increased susceptibility to colorectal cancer should be referred for genetic counseling for formal evaluation and possible testing. Detailed guidelines on the management of patients with dominantly inherited colorectal cancer have been previously published by the society.9 Routine laboratory examinations including complete blood cell counts, liver function tests, and chemistry panel should be performed based on patient comorbidities as indicated for preparation for general anesthesia. Carcinoembryonic antigen (Cea) levels should be assessed before elective treatment of rectal cancer for the establishment of baseline values and during the surveillance period to monitor for signs of recurrence.10 although higher levels of Cea have been correlated with poorer prognosis, the data are insufficient to justify the use of a high preoperative Cea alone as an indication for adjuvant therapy.11,12 a confirmed rise in the Cea during the surveillance period should prompt further investigation for recurrent disease13. at present there is TABLE 1. The GRADE system-grading recommendationsa 1A Strong recommendation, high quality evidence Benefits clearly outweigh risk and burdens or vice versa RCTs without important limitations or overwhelming evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation 1B Strong recommendation, moderate quality evidence Benefits clearly outweigh risk and burdens or vice versa RCTs with important limitations (inconsistent results, methodological flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Strong recommendation, can apply to most patients in most circumstances without reservation 1C Strong recommendation, low or very low quality evidence Benefits clearly outweigh risk and burdens or vice versa Observational studies or case series Strong recommendation but may change when higher quality evidence becomes available 2A Weak recommendation, high quality evidence Benefits closely balanced with risks and burdens RCTs without important limitations or overwhelming evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patients’ or societal values 2B Weak recommendations, moderate quality evidence Benefits closely balanced with risks and burdens RCTs with impo0rtant limitations (inconsistent results, methodological flaws, indirect or imprecise) or exceptionally strong evidence from observational studies Weak recommendation, best action may differ depending on circumstances or patients’ or societal values 2C Weak recommendation, low or very low quality evidence Uncertainty in the estimates of benefits, risks, and burden; benefits, risk, and burden may be closely balanced Observational studies or case series Very weak recommendations; other alternatives may be equally reasonable RCT = randomized controlled trial. aAdapted from: Guyatt G, Gutterman D, Baumann MH, et al. Grading strength of recommendations and quality of evidence in clinical guidelines: report from an American College of Chest Physicians Task Force. Chest. 2006;129:174–181. Used with permission. www.medlive.cn Diseases of the Colon & ReCtum Volume 56: 5 (2013) 537 insufficient evidence to support the routine use of other tumor markers such as Ca19-9 in the routine evaluation of patients with rectal cancer..11 2. As part of a full physical examination, proctosigmoid- oscopy should be performed in conjunction with a digi- tal rectal examination to determine the distance of the lesion from the anal verge, mobility, and to assess its position in relation to the sphincter complex. Grade of Recommendation: Strong recommendation based on low quality evidence, 1C. as part of a full physical examination, proctosigmoidos- copy should be performed in conjunction with a digital rectal examination (DRe) by the operating surgeon to determine the distance of the lesion from the anal verge. Clinical evaluation by DRe can be informative regarding the degree of tumor fixation and location and should be performed in conjunction with formal clinical staging by ultrasound or mRi. Proper identification of the tumor lo- cation also permits treatment stratification for sphincter preservation or for the assessment of treatment benefit from neoadjuvant therapy. 3. When possible, all patients with rectal cancer should undergo a full colonic evaluation with histological as- sessment of all colorectal lesions before treatment. Grade of Recommendation: Strong recommendation based on moderate quality evidence, 1B. Complete assessment of the colon should be performed (preoperatively or postoperatively) because the incidence of synchronous cancers is 1% to 3%, and the incidence of synchronous polyps is 30%.14–17 Colonoscopy is the pre- ferred option because it offers the opportunity to confirm the diagnosis histologically and to endoscopically remove any synchronous polyps. an increasing number of patients may be diagnosed by alternative methods and referred for surgical therapy without having already undergone a com- plete endoluminal examination. in the case of an incom- plete colonoscopy, a double-contrast barium enema18 or Ct colonography may be used preoperatively.19–22 if pre- operative colon evaluation is not feasible, early postopera- tive evaluation (within 3 to 6 months) is reasonable. histological diagnosis should be confirmed before elective resection. this is particularly true if neoadjuvant therapy is being considered. for lesions amenable to local excision, with nondiagnostic initial biopsy results, infor- mation may be obtained at the time of transanal excision. subsequent surgical management should be guided by the resultant histopathological findings. B. Staging 1. Rectal cancer staging should be routinely performed according to the American Joint Committee on Cancer TNM system with assignment of both pretreatment clinical and posttreatment pathological stage. Grade of Recommendation: Strong recommendation based on moderate quality evidence, 1B. the tnm system, as defined by the american Joint Com- mittee on Cancer, is the most commonly used system and is based on the depth of local tumor invasion (t stage), the ex- tent of regional lymph node involvement (n stage), and the presence of distant metastasis (m stage) (tables 2 and 3).23 staging for rectal cancer should consider both the clinical stage (upon which subsequent treatment deci- sions are made) and the final pathological stage, which may represent the most important prognostic factor in rectal cancer.23 although the overall tnm system was developed to stratify the prognosis of patients before the advent of neoadjuvant therapy and tme, current data suggest that, among patients receiving neoadjuvant thera- py, final pathological stage stratifies disease-free survival.24 increasing use of preoperative treatment has led to the re- quirement that the pathological staging may incorporate a "downstaging" effect and the prefix "y" is attached to the pathology report (designated "p") to reflect previous TABLE 2. AJCC TNM definitions (seventh edition) TNM Definitions Primary tumor (T) TX Primary tumor cannot be assessed T0 No evidence of primary tumor Tis Carcinoma in situ T1 Tumor invades the submucosa T2 Tumor invades the muscularis propria T3 Tumor invades the subserosa or into nonperitonealized perirectal tissues T4a Tumor penetrates to the surface of the visceral peritoneum T4b Tumor directly invades or is adherent to other organs or structures Regional lymph nodes (N) NX Regional lymph nodes cannot be assessed N0 No regional nodal metastasis N1 Metastasis in one to three regional lymph nodes N1a Metastasis in one regional lymph node N1b Metastasis in 2–3 regional lymph nodes N1c Tumor deposit(s) in the subserosa, mesentery, or nonperitonealized perirectal tissues without regional nodal metastasis N2 Metastasis in 4 or more regional lymph nodes N2a Metastasis in 4–6 regional lymph nodes N2b Metastasis in 7 or more regional lymph nodes Distant metastasis (M) M0 No distant metastasis M1 Distant metastasis M1a Metastasis confined to 1 organ or site M1b Metastasis in more than one organ/site or the peritoneum AJCC = American Joint Committee on Cancer. Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer Science and Business Media LLC, www.springer.com.23 www.medlive.cn monson et al: PRaCtiCe PaRameteRs foR the manaGement of ReCtal CanCeR (ReViseD)538 multidisciplinary treatment.25 Preoperative staging should also be prefixed by the staging modality including c for clinical, u for ultrasound, mr for mRi, and ct for Ct scan. 2. Clinical staging of the primary tumor by endorectal ultrasound (EUS) or dedicated high resolution rectal MRI should be performed. Grade of Recommendation: Strong recommendation based on moderate quality evi- dence, 1B. endorectal ultrasound with rigid or flexible probes and mRi with either endorectal or increasingly phase array coils are the primary tumor-staging modalities of choice. there are advantages and disadvantages to each modal- ity, and they can, therefore, be considered complementary, eg, eus may be better for distinguishing between t1 and t2 tumors. endorectal ultrasound is less accurate in the assessment of large bulky lesions (t4 stage accuracy of 44%–50%), and stenotic lesions can pose difficulties be- cause the probe may be unable to traverse the lesion, lead- ing to suboptimal staging.26,27 accurate detection of involved lymph nodes remains a diagnostic challenge for all imaging modalities. nodal staging is complicated by the fact that nodal size criteria are less well defined and, in general, are inaccurate because both benign and malignant nodes overlap to a great degree.28,29 in a meta-analysis, the sensitivities and specificities of imaging modalities for nodal staging were as follows: Ct (55% and 74%), eus (67% and 78%), and mRi (66% and 76%).30 however, staging accuracy has more recently improved based on the identification of specific features on mRi such as mixed signal intensity and irregular borders that identify malignant lymph nodes. tumor circumferential margin (CRm) is defined as the shortest distance between the rectal tumor (including noncontiguous tumor) and the mesorectal fascia (tme).31 although not incorporated in the tnm staging system, positive CRm status is an important prognostic factor and is strongly associated with an increased risk of local recurrence and decreased survival.31,32 involvement of the mesorectal fascia by tumor increases the likelihood of local recurrence following tme by more than 4-fold.33 the definition of a positive margin in the tnm classification is 0 mm, but, in most cases, the CRm is considered positive when it is ≤1 mm.25 magnetic resonance imaging is particularly useful in the evaluation of the CRm.34 the plane of the mesorectal fascia seen on mRi correlates with the fascia propria of the mesorectum resected with tme.34,35 findings on pretreatment mRi can therefore be used for surgical planning. although mRi is useful in the preoperative staging of rectal cancer, specific protocols have been developed for this utility. standard pelvic mRi may not provide the same information that these protocols will.36 3. All patients with rectal cancer should have preopera- tive radiological staging to assess for metastatic disease. Grade of Recommendation: Strong recommendation based on moderate quality evidence, 1B. the liver and lungs are the most frequent sites of metastat- ic disease from rectal cancer. 37,38 therefore, preoperative radiographic staging including a Ct scan of the chest, ab- domen, and pelvis should be routinely performed before the elective surgical resection of rectal cancer. this permits the detection and evaluation of local organ penetration or synchronous metastases, which may require a change in the treatment strategy, eg, chemotherapy rather than sur- gery first or potential simultaneous resection of both the primary tumor and the metastatic sites. a Ct scan of the chest is more sensitive than a chest x-ray for detecting pul- monary metastases.39 furthermore, a baseline pulmonary Ct enables indeterminate lesions to be characterized with more confidence on follow-up.39 alternative imaging strategies for patients with con- trast dye allergies may include an mRi of the abdomen and pelvis with a non-contrast-enhanced chest Ct or fDG-Pet imaging. however, the role of fDG-Pet/Ct imaging is currently still evolving. although Pet has the TABLE 3. AJCC stage groupings (seventh edition) Stage T N M Stage 0 Tis N0 M0 Stage 1 T1, T2 N0 M0 Stage IIA T3 N0 M0 Stage IIB T4a N0 M0 Stage IIC T4b N0 M0 Stage IIIA T1, T2 N1/N1c/N2a M0 Stage IIIB T3, T4aT2, T3T1,T2 N1/N1cN2aN2b M0 Stage IIIC T4aT3, T4aT4b N2aN2bN1/N2 M0 Stage IVA Any T Any N M1a Stage IVB Any T Any N M1b AJCC = American Joint Committee on Cancer. Used with the permission of the American Joint Committee on Cancer (AJCC), Chicago, Illinois. The original source for this material is the AJCC Cancer Staging Manual, Seventh Edition (2010) published by Springer Science and Business Media LLC, www.springer.com.23 www.medlive.cn Diseases of the Colon & ReCtum Volume 56: 5 (2013) 539 potential to identify some occult lesions not demonstrated o