Guidelines 2000 for colon and rectal cancer surgery

Urinary tract involvement by colorectal cancer

PURPOSE

Involvement of the urinary tract by colorectal cancer is sufficiently rare to be encountered by an individual surgeon on an infrequent basis. The aim of this review is to highlight technical and oncologic issues that should be considered when dealing with complex colorectal cancer that involves the urinary tract.

METHODS

The relevant literature from 1975 to 2001 was identified using the MEDLINE database of the U.S. National Library of Medicine and reviewed. Because of the diversity of forms of presentation of urologic involvement, few randomized, controlled trials are available, with most evidence derived from retrospective studies.

RESULTS

Three distinct clinical situations in which the urinary tract may be affected by colorectal cancer were identified: involvement by primary colorectal cancer, involvement by recurrent cancer, and unexpected intraoperative findings of urinary tract involvement. Management strategies to identify and treat locally advanced primary or recurrent colorectal cancer involving the urinary tract improve survival with acceptable morbidity and mortality. Careful preoperative assessment of all patients with colorectal cancer will reduce unexpected identification of urinary tract invasion at the time of surgery. In patients in whom cure is not possible, endourologic techniques combined with judicious surgical resection can provide high-quality palliation. Optimal care of many of these conditions is facilitated by specialist urologic advice.

CONCLUSIONS

The wide spectrum of possible urinary tract involvement by colorectal cancer requires individual patient-specific and disease-specific consideration. The literature offers important guidelines that aid decision making and improve management of these challenging problems.

The pathological assessment of mesorectal excision: implications for further treatment and quality management

BACKGROUND AND AIMS

Most clinical practice guidelines today recommend total mesorectal excision (TME) for carcinoma of the middle and lower rectal thirds and partial mesorectal excision (PME) for the upper rectal third. However, these procedures may not always fulfill the oncological requirements. The pathological examination of resected rectal carcinomas should always include a visual assessment of the mesorectal excision to ensure oncological adequacy and appropriate quality. The clinical practice guideline of the German Cancer Society recommends reporting of the distal extent of mesorectal excision (total or partial without coning) and the excision in an inviolate fascial envelope.

PATIENTS AND METHODS

Reporting schemas of assessment and documentation for daily use and for studies are presented.

RESULTS

Careful macroscopic evaluation of the resection specimen should be standardized. This may be supplemented by stain marking after postoperative filling the inferior mesenteric or superior rectal artery with ink or methylene blue solution. Photodocumentation is highly desirable. The pathological assessment of adequacy of mesorectal excision should be taken into account in selection for adjuvant radiotherapy. Objective macro- and microscopic assessment of mesorectal excision by pathologists is essential for quality management throughout patient care and in clinical trials.

New developments in therapy for colorectal cancer

Colorectal cancer remains a significant cause of cancer death, and its treatment is the subject of active, ongoing investigation within all treatment modalities, including surgery, chemotherapy, and radiotherapy. In this review we discuss selected interesting and important research findings since the year 2000 and comment on their potential impact on the adjuvant and advanced disease management of patients with colon and rectal cancer.

Methods and results of sphincter-preserving surgery for rectal cancer

BACKGROUND

Sphincter preservation is the goal in the treatment of rectal cancer and should be considered in all patients with an intact sphincter. Sphincter preservation for tumors of the upper rectum is easily achieved, but surgical management of cancer of the mid and lower third of the rectum continues to evolve. Several recent advances may influence future treatment strategies.

METHODS

We reviewed the literature to identify the current methods of sphincter-preserving surgery and their oncologic and functional results.

RESULTS

Proctectomy with total mesorectal excision reduces the incidence of local recurrence to less than 10% while preserving genitourinary function. The use of preoperative radiotherapy may further diminish the risk of local recurrence. In selected patients, partial resection of the anal sphincter may avoid definitive colostomy without compromising oncologic outcome. In contrast, the role of local resection of rectal cancer remains controversial. Restoration of continuity by means of a colonic reservoir reduces stool frequency and urgency and improves continence when compared to a straight coloanal anastomosis. The transverse colpoplasty pouch may allow pouch construction in patients in whom it is currently impossible, but long-term follow-up is not yet available.

CONCLUSIONS

Sphincter-preserving surgery is possible for the majority of patients with rectal cancer. Optimal functional results may be obtained by a nerve-sparing operative technique and by use of a colonic reservoir for reconstruction following resection of mid or low rectal cancers.

Colorectal carcinoma: diagnostic, prognostic, and molecular features

Surgical resection is the primary treatment modality for colorectal cancer, and the pathologic assessment of the resection specimen provides data that is essential for patient management, including the estimation of postoperative outcome and the rationale for adjuvant therapy. The essential elements of the pathological assessment of colorectal cancer resection specimens include the pathologic determination of TNM stage, tumor type, histologic grade, status of resection margins, and vascular invasion. The prognostic and/or predictive value of these elements, as well as guidelines for their derivation and interpretation, are reviewed in detail. Other tissue-based prognostic factors that are strongly suggested by existing data to have stage-independent prognostic value or to predict response to adjuvant therapy but that have not yet been validated for routine patient care are also reviewed. These include perineural invasion, tumor border configuration, host immune response to tumor, and molecular features such as microsatellite instability or loss of heterozygosity of chromosome 18. The need for high-quality, reproducible pathologic data in the care of the colorectal cancer patient, and the dependence of that data on standardization of all aspects of pathological assessment, is emphasized.

Multimodal CME for surgeons and pathologists improves colon cancer staging

BACKGROUND

Optimal treatment of localized colorectal cancer (CRC) depends on accurate retrieval and assessment of lymph nodes (LN) in the resected specimen.

METHODS

Formal CE, informal opinion leadership and reinforcing strategies aimed at pathologists and surgeons to improve LN assessment were implemented.

RESULTS

In the pre-intervention period a median of 8 lymph nodes were assessed in making a designation of Stage II CRC (n = 115). Thirty months later (post-intervention period) the median number of LN reported in Stage II CRC increased to 18 (n = 41), p < 0.001.

CONCLUSION

A durable improvement in staging was realized through a multipronged change initiative aimed at both surgeons and pathologists.

Anorectal anatomy

A working knowledge of anorectal and pelvic anatomy is crucial for the understanding of normal function, pathogenesis and surgical treatment of anorectal diseases. In a field of unlimited details and varying definitions, our goal is to provide an overview of anatomic concepts relevant for the practical management of patients.

Rectal washout with cytotoxic solution can be extended to the whole colon

BACKGROUND

Rectal irrigation with a cytotoxic agent does not kill viable intraluminal cancer cells proximal to the primary tumour. To prevent implantation of these cells at the time of restorative proctectomy, the feasibility of retrograde whole-colon irrigation just before surgery was explored.

METHODS

The cytotoxic efficacy of different combinations of povidone-iodine (PVPI) and Gastrografin was tested with the trypan blue exclusion test on a human colon carcinoma cell line (SW620) in vitro. Subsequently, a retrograde whole-colon lavage with PVPI 5 per cent and Gastrografin 12 per cent was performed in 14 euthyroid, non-allergic patients with colorectal cancer using a colostomy irrigation set. Thyroid function and mucosal damage were assessed.

RESULTS

It took 2 min and approximately 1 litre of infused solution to reach the caecum in all patients. The solution was 100 per cent tumoricidal in vitro and remained so after colonic irrigation. Total serum tri-iodothyronine (T3) levels decreased and those of reverse T3 increased, but normalized after 1 week. Superficial epithelial desquamation was observed shortly after irrigation; however, complete restoration occurred within 7 days.

CONCLUSION

A rectal washout can easily be extended to a retrograde irrigation of the whole colon in elective colorectal cancer surgery. This may help to prevent anastomotic and local recurrence due to implantation of viable exfoliated tumour cells.

Comparative detection of lymph node micrometastases of stage II colorectal cancer by reverse transcriptase polymerase chain reaction and immunohistochemistry

PURPOSE

Inconsistent conclusions have been drawn about the clinical significance of micrometastases in lymph nodes (LNs) of node-negative colorectal cancer (CRC) patients. We performed a comparative study of detection of micrometastases using immunohistochemistry (IHC) by anti-cytokeratin antibody and carcinoembryonic antigen (CEA)-specific reverse-transcriptase polymerase chain reaction (RT-PCR) in the same patients, in an attempt to move closer to their clinical application.

PATIENTS AND METHODS

Sixty-four CRC patients, with RNA of good quality available from paraffin-embedded LN specimens, were selected from 84 stage II patients who underwent curative surgery between 1988 and 1996. We investigated associations between the presence of micrometastases by each method and prognosis.

RESULTS

Micrometastases were detected in 19 (29.6%) of 64 patients by RT-PCR and in 35 (54.7%) of 64 patients by IHC. By RT-PCR analysis, patients exhibiting a positive band for CEA mRNA had a significantly worse prognosis than those who were RT-PCR-negative, with respect to both disease-free and overall survival (P =.027 and.015, respectively). By IHC analysis, the presence of micrometastasis did not predict patient outcome in terms of either disease-free or overall survival. Infiltrating pattern of tumor growth characteristic was significantly associated with shorter disease-free survival among various clinical or pathologic factors. By multivariate Cox regression analysis, micrometastasis detected by RT-PCR and the Crohn's-like lymphoid reaction were both independent prognostic factors.

CONCLUSION

Micrometastases detected by RT-PCR, but not IHC, may be of clinical value in identifying patients who may be at high risk for recurrence of CRC and who are therefore likely to benefit from systemic adjuvant therapy.

Adjuvant therapy of cancers of the colon and rectum

Important advances have been made in our understanding of the role of adjuvant therapy for colorectal cancer. Current standard 5FU-based regimens have been convincingly shown to reduce the incidence of recurrences and to prolong overall survival in patients with resected stage III colon cancer. Colon cancer patients with stage II disease have a better-overall prognosis than those with stage III; however, the relative merits of adjuvant treatment in these patients remains controversial. Combined chemotherapy plus radiation therapy is currently the standard adjuvant approach for stage II and III rectal cancer patients. Despite the advances that have been made, far too many patients with resectable colorectal cancer ultimately relapse and die of their disease. There remains a pressing need for continued development of improved adjuvant treatments. Participation of eligible patients in clinical trials must continue to be actively encouraged. Only in this way will we be able to continue to build and expand on the progress that has been made thus far.

Rectal cancer: the sphincter-sparing approach

There is considerable skepticism regarding sphincter-preserving surgery for rectal cancer, and 40% to 60% APR rates are reported in many prospective studies. Despite radical surgery, 20% positive margin rates are frequently reported. Rectal carcinoma responds to preoperative chemoradiation therapy with a 10% to 15% pathologic complete response rate. Preoperative therapy offers an opportunity to reduce the positive margin rate and to reduce the APR rate. Because there is significant tumor regression with preoperative therapy, distal margins of less 1 cm are acceptable and do not result in suture line recurrence. APR rate of less than 10% is feasible and better chemotherapy with radiation therapy will reduce the APR to less than 5%.

A prospective, blinded assessment of the impact of preoperative staging on the management of rectal cancer

BACKGROUND & AIMS

The influence of preoperative staging of rectal carcinoma on therapeutic decisions is uncertain. The use of fine-needle aspiration (FNA) of perirectal nodes in this setting has not been evaluated. The aim of this prospective, blinded study of patients with rectal cancer was to assess the impact of preoperative staging on treatment decisions and compare the tumor (T), nodal (N) staging performance characteristics of pelvic computed tomography (CT), rectal endoscopic ultrasonography (EUS), and EUS FNA.

METHODS

Eighty consecutive patients with newly diagnosed rectal cancer were prospectively evaluated. Therapy decisions were recorded after sequential disclosure of staging information to the patient's surgeon.

RESULTS

In 31% of patients (95% confidence interval, 21%-42%), EUS staging information changed the surgeon's original treatment plan based on CT alone. The further addition of FNA changed therapy in one patient. T staging accuracy was 71% (CT) and 91% (EUS) (P = 0.02); N staging accuracy was 76% (CT), 82% (EUS), and 76% (EUS FNA) (P = NS).

CONCLUSIONS

Preoperative staging with EUS results in more frequent use of preoperative neoadjuvant therapy than if staging was performed with CT alone. The addition of FNA only changed the management of one patient, whereas FNA did not significantly improve N staging accuracy over EUS alone. FNA seems to offer the most potential for impacting management in those patients with early T stage disease, and its use should be confined to this subgroup of patients. EUS is more accurate than CT for determining T stage of rectal carcinoma.

Prognostic evaluation of stage B colon cancer patients is improved by an adequate lymphadenectomy: results of a secondary analysis of a large scale adjuvant trial

OBJECTIVE

To determine if the extent of lymphadenectomy (number of recovered lymph nodes) was associated with long-term outcome in patients operated on for stage B and C colon cancer.

SUMMARY BACKGROUND DATA

Lymphatic spreading is the main prognostic indicator in colon cancer patients, although the optimal extent of lymphadenectomy and its prognostic impact are still unknown.

METHODS

In 3,648 patients (median follow-up 3.6 years) enrolled in two consecutive INTACC multicentric trials on adjuvant therapy for colon cancer, we studied the association of the number of recovered nodes with overall survival and relapse free survival by means of univariate and Cox regression analysis.

RESULTS

The worst overall survival was related to ages > 65 (risk ratio [RR] = 1.30), higher grading (RR = 1.96). Better overall survival was related to female gender (RR = 0.80) and to higher number of recovered nodes (8-12 nodes, RR = 0.46, 13-17 nodes, RR = 0.76, nodes > or = 18, RR = 0.79). The same pattern was observed for relapse free survival. Longer overall and relapse free survival were related to a higher number of recovered nodes with P =.034 and P =.003 respectively (stratified analysis for absence or presence of positive nodes). Stage B patients with fewer than 7 nodes in the specimen had both shorter overall survival (P =.0000) and relapse free survival (P =.0016) than the other B patients. Outcome of stage C patients was not related to the number of recovered nodes (P =.28 and 0.12 respectively). The interaction test between stage of disease and number of recovered nodes was statistically significant (P =.017).

CONCLUSIONS

Stage B patients with a small number of examined nodes may be understaged. Thus, these patients might be considered for adjuvant therapy because of their poorer life expectancy than other stage B patients. For stage C patients, the number of recovered nodes does not seem to affect long-term outcome.

Emerging standards of radiotherapy combined with radical rectal cancer surgery

For patients with resectable rectal cancer treated with total mesorectal excision, the routine use of radiotherapy should be omitted for stage I of the disease and for lesions located higher than 10 cm from the anal verge. Preoperative radiotherapy may be considered for all patients with a lesion with deep perirectal fat infiltration located in the lower two thirds of the rectum. The other option is to offer postoperative radiotherapy for patients with a positive surgical margin, N+ stage disease, mesorectal tumour implants, high tumour grade, perineural invasion, extramuscular blood and lymphatic vessel invasion and with inadvertent tumour perforation. The lower risk of small bowel damage and probable higher efficacy are arguments for the use of preoperative radiotherapy instead of postoperative radiotherapy. The impairment of anorectal function appears to be most frequent late postirradiation sequel. The analysis of acute complications (including toxic deaths) compliance, cost and convenience favours 5 x 5 Gy preoperative irradiation with immediate surgery for patients with resectable tumours in comparison to other commonly used schemes of radiotherapy. These advantages should be weighed against approximately 1.5% risk of late neurotoxicity. There is no clear answer to the question whether preoperative conventional radio(chemo)therapy offers an advantage in sphincter preservation. To answer this question, the results of two ongoing randomised trials are awaited. For patients with unresectable cancers, long-term preoperative radio(chemo)therapy with delayed surgery is a preferable scheme. The total mesorectal irradiation should be employed for mid- and low-lying lesions. Therefore, during radiotherapy planning, a contrast enema should be used to identify the anorectal ring, anatomically corresponding with the lowest edge of the mesorectum.

Predictors of surgical outcomes

The foundation of surgical decision-making has always been the risk-to-benefit ratio. Traditionally, the risks of complications and death, predicted by comorbid conditions, have been balanced against the benefits of disease management; that is, relief of symptoms or prevention of disease-related complications. Increasingly, patient preference and quality-of-life outcomes are entering into the decision-making process even at the price of modest increases in risk. In addition, the role of the surgeon as a predictor of outcomes has come under close scrutiny and has been demonstrated as having an effect on a number of important surgical outcomes. In the future, our methods for analyzing and reporting surgical outcomes will have to accommodate new predictors.