Preoperative evaluation and postoperative surveillance for patients with colorectal carcinoma

Evaluation of Serum Carcinoembryonic Antigen Monitoring in the follow-up of Colorectal Cancer Patients with Metastatic Lymph Nodes and a Normal Preoperative Serum Level

The value of serial serum carcinoembryonic antigen (CEA) assay in the follow-up of colorectal cancer patients with metastatic lymph nodes and normal (≤ 5 ng/ml) preoperative CEA levels, was examined in this study. Thirty-eight patients were studied and compared with 22 patients with elevated CEA levels. The overall sensitivity of CEA for the diagnosis of recurrence was 36%. Postoperative CEA was strongly influenced by the site of recurrence. CEA monitoring showed the best results in patients who developed hepatic metastases (sensitivity 60%, specificity 94%, positive predictive value 60%, and negative predictive value 94%), and was ineffective for the detection of locoregional or pulmonary metastases. The results indicate that elevation of CEA in the postoperative course of these patients is an indicator of the presence of hepatic metastases. Postoperative CEA monitoring should not be omitted in Dukes C patients with normal preoperative levels, and is more reliable for the detection of liver metastases.

Diagnostic precision of carcinoembryonic antigen in the detection of recurrence of colorectal cancer

INTRODUCTION

The aim of the study was to evaluate the diagnostic precision of serum carcinoembryonic antigen (CEA) in the detection of local or distant recurrence following resectional surgery for colon and rectal cancer.

METHODS

Quantitative meta-analysis was performed on 20 studies, comparing serum CEA with radiological imaging and/or pathology in detecting colorectal cancer (CRC) recurrence in 4285 patients. The cut-off for a 'positive' CEA ranged from 3 to 15 ng/ml between the various studies. Sensitivity, specificity and diagnostic odds ratio (DOR) were calculated for each study. Summary receiver operating characteristic curves (SROC) and sub-group analysis were undertaken.

RESULTS

The overall sensitivity and specificity of CEA for detecting CRC recurrence was 0.64 (95% CI: 0.61-0.67) and 0.90 (95% CI: 0.89-0.91), respectively. The area under the SROC curve was 0.75 (SE=0.04) and the diagnostic odds ratio was 18.44 (95% CI: 11.94-28.49). A CEA cut-off of 5 ng/ml yielded a higher diagnostic odds ratio than a cut-off of 3 ng/ml (15.5 vs. 11.1). Using meta-regression analysis the optimum CEA cut-off point for the best combination of sensitivity and specificity was 2.2 ng/ml. On sub-group analysis high quality studies, and those involving > or =100 patients yielded a marginal improvement in the sensitivity and specificity with minimal change to the SROC.

CONCLUSION

Serum CEA is a test with high specificity but insufficient sensitivity for detecting CRC recurrence in isolation. A cut-off of 2.2 ng/ml may provide an ideal balance of sensitivity and specificity. It may be useful as a first-line surveillance investigation in patients during surgical follow-up based on serial CEA measurements using temporal trends in conjunction with clinical, radiological and/or histological confirmation.

Follow-up of patients with curatively resected colorectal cancer: a practice guideline

BACKGROUND

A systematic review was conducted to evaluate the literature regarding the impact of follow-up on colorectal cancer patient survival and, in a second phase, recommendations were developed.

METHODS

The MEDLINE, CANCERLIT, and Cochrane Library databases, and abstracts published in the 1997 to 2002 proceedings of the annual meeting of the American Society of Clinical Oncology were systematically searched for evidence. Study selection was limited to randomized trials and meta-analyses that examined different programs of follow-up after curative resection of colorectal cancer where five-year overall survival was reported. External review by Ontario practitioners was obtained through a mailed survey. Final approval of the practice guideline report was obtained from the Practice Guidelines Coordinating Committee.

RESULTS

Six randomized trials and two published meta-analyses of follow-up were obtained. Of six randomized trials comparing one follow-up program to a more intense program, only two individual trials detected a statistically significant survival benefit favouring the more intense follow-up program. Pooling of all six randomized trials demonstrated a significant improvement in survival favouring more intense follow-up (Relative Risk Ratio 0.80 (95%CI, 0.70 to 0.91; p = 0.0008). Although the rate of recurrence was similar in both of the follow-up groups compared, asymptomatic recurrences and re-operations for cure of recurrences were more common in patients with more intensive follow-up. Trials including CEA monitoring and liver imaging also had significant results, whereas trials not including these tests did not.

CONCLUSION

Follow-up programs for patients with curatively resected colorectal cancer do improve survival. These follow-up programs include frequent visits and performance of blood CEA, chest x-rays, liver imaging and colonoscopy, however, it is not clear which tests or frequency of visits is optimal. There is a suggestion that improved survival is due to diagnosis of recurrence at an earlier, asymptomatic stage which allows for more curative resection of recurrence. Based on this evidence and consideration of the biology of colorectal cancer and present practices, a guideline was developed. Patients should be made aware of the risk of disease recurrence or second bowel cancer, the potential benefits of follow-up and the uncertainties requiring further clinical trials. For patients at high-risk of recurrence (stages IIb and III) clinical assessment is recommended when symptoms occur or at least every 6 months the first 3 years and yearly for at least 5 years. At the time of those visits, patients may have blood CEA, chest x-ray and liver imaging. For patients at lower risk of recurrence (stages I and Ia) or those with co-morbidities impairing future surgery, only visits yearly or when symptoms occur. All patients should have a colonoscopy before or within 6 months of initial surgery, and repeated yearly if villous or tubular adenomas >1 cm are found; otherwise repeat every 3 to 5 years. All patients having recurrences should be assessed by a multidisciplinary team in a cancer centre.

Prognostic value of P53 mutations in rectal carcinoma

The influence of p53 mutations on the response to ionizing radiation and survival was retrospectively evaluated in patients treated with preoperative radiotherapy for rectal carcinoma. From 1989 to 1991, 86 rectal cancer patients treated by preoperative radiotherapy were included in this series. For all patients, endorectal sonography (to define ultrasonography TNM [uTNM]) was performed before treatment; 19 patients were classified as stage 1, 27 as stage 2 and 40 as stage 3. Response to radiotherapy (39 Gy in 13 fractions delivered in 17 days) was assessed by comparing the uT and the T obtained by histologic examination of the resected specimen (TNM classification). A rectal cancer biopsy was performed before treatment and enabled the search for p53 mutations by denaturing gradient gel electrophoresis (DGGE) and sequencing. The status of the p53 gene was correlated with the response to radiotherapy and survival. Forty-nine percent of the tumors presented abnormal DGGE profiles. The prevalence of p53 mutations was significantly higher in patients who did not respond to radiotherapy (63%) than in those who did respond (34%) (p < 0.01). Presence of a p53 mutation was associated with significantly shorter 5-year survival compared to patients without mutations (p < 0.02). In a multivariate analysis, p53 mutation status remained a prognostic factor independent of tumor posttreatment staging (p < 0.05). p53 status is an independent prognostic factor of response to radiotherapy and survival in rectal carcinoma.

Surgical aspects of colorectal carcinoma

Colorectal surgery remains the cornerstone of curative therapy for colorectal carcinoma. The development of new instruments permitting technical advances, however, as well as the advent of effective adjuvant therapies and the progress in staging and early detection, have changed some of the indications for surgery as well as surgical methods. Even so, emphasis has always been placed on thorough preoperative evaluation and staging. This article explores the current state of standard surgical care of the colorectal cancer patient with special attention given to preoperative evaluation, standard and controversial surgical therapies, and postoperative surveillance.

Value of carcinoembryonic antigen monitoring in curative surgery for recurrent colorectal carcinoma

PURPOSE

This study is designed to review a carcinoembryonic antigen (CEA)-driven postoperative protocol designed to identify patients suitable for curative reresection when recurrent colorectal cancer is identified.

METHODS

A total of 285 patients who were operated on for colon or rectal carcinoma between 1981 and 1985 were evaluated (with CEA levels) every two months for the first two years, every three months for the third year, every six months for years 4 and 5, and annually thereafter. CEA levels above 5 microg were considered abnormal and were evaluated with diagnostic imaging and/or endoscopy.

RESULTS

Follow-up was available for 280 patients (98.2 percent). Distribution of patients by Astler-Coller was: A, 14 percent; B1, 20 percent; B2, 39 percent; C1, 5 percent; C2, 21 percent. There were 62 of 280 patients (22 percent) who developed elevated CEA levels, with 44 patients who demonstrated clinical or radiographic evidence of recurrence. Eleven patients were selected for surgery with curative intent (4 hepatic resections, 1 pulmonary wedge resection, 2 abdominoperineal resections, 2 segmental bowel resections, and 2 cranial metastasectomies). Three of 11 patients (27 percent) benefited and have disease-free survivals greater than 60 months. Of the 223 patients without elevated CEA, 22 (9.9 percent) had recurrent cancer without any survivors. Overall, 3 of 285 patients (1.1 percent) were cured as a result of CEA follow-up.

CONCLUSION

CEA-driven surgery is useful in selected patients and can produce long-term survivors.

Five primary synchronous neoplasms of the gastrointestinal tract

Multiple primary malignant neoplasms in a single patient have been well documented in the literature over the past hundred years. The lesions can be limited to a single organ or involve multiple organ systems. It is relatively common for patients with colorectal carcinoma or carcinoid tumors to have more than one primary neoplasm. Colonic lesions can be synchronous or metachronous in presentation and colonic or extracolonic in location. We present a patient with five primary synchronous neoplasms of the gastrointestinal tract, involving the stomach, small bowel, and colon. The patient had no evidence of metastatic disease and underwent resection of all the lesions. This case illustrates the need for a thorough search for additional neoplasms in the treatment of patients with cancer.

Impact of intraoperative ultrasonography on treatment strategy for colorectal cancer

The impact of intraoperative ultrasonography (IOUS) on treatment strategy was studied in 122 patients with primary colorectal cancer. All patients underwent preoperative liver imaging by ultrasonography and computed tomography (CT). After curative resection of the primary tumour patients were eligible for adjuvant chemotherapy. The findings on IOUS were assessed by ultrasonography 6 months after laparotomy. Of 34 patients with suspected liver metastases on ultrasonography or CT, the diagnosis was confirmed by IOUS in 21. In the remaining 13 patients the suspect lesions were shown to be benign. Of the 88 patients with normal preoperative imaging results, suspect lesions were detected in five; in four the lesion was found by IOUS only. One of these four also had an extrahepatic metastasis. At follow-up the diagnosis of metastasis proved to be wrong in two of the remaining three patients, so IOUS was helpful in only one patient. Surgical management was not markedly influenced by findings on IOUS in any patient. However, IOUS correctly changed the stage of the disease, and consequently postoperative treatment, in 14 patients (11 per cent). Two patients were erroneously excluded from the adjuvant protocol following an incorrect diagnosis based on IOUS.

Surgical treatment options for colorectal cancer

The aging of our national population is recognized as a major achievement of modern society. The National Institutes of Health have recently redefined "old" as beginning at age 70. This segment of our population lead active and productive lives. An unfortunate association of aging is the development of neoplasia. The incidence of colorectal cancer continues to escalate, with 150,000 cases expected each year, representing 15% of all cancer, two thirds of which are found in patients older than age 65. Forty percent of these patients present with advanced disease. Little change in survival by stage has been noted in the last 30 years. Surgical resection offers the only opportunity for cure as well as affording significant palliation in patients with advanced disease. Although age alone does not increase operative risks, comorbidity and emergency surgery are confounding factors. Repeated studies have shown that acceptable mortality and morbidity may be achieved by surgical resection for cure and for palliation in the elderly, thus age alone should not be a limiting factor. Key elements in management are early detection with surgical intervention before stage advancement or before complications occur (i.e., obstruction, perforation). When possible, comorbid factors, such as nutritional deficits, cardiovascular decompensation, and pulmonary insufficiency should be corrected. The appropriate use of mechanical bowel preparation and perioperative antibiotics should be emphasized. Surgical management should encourage adequate resection for cure or palliation rather than bypass or diversion. Proximal shifts in colon cancer location and improved technology frequently make resection with anastomosis possible rather than end colostomy. Multidisciplinary approaches to rectal cancer offer significant opportunities for sphincter preservation. Local excision with or without radiation therapy offers an occasional opportunity for treatment of rectal cancer in highly selective cases, also with sphincter preservation.

Endoluminal ultrasonography in the follow-up of patients with rectal cancer

One principal aim in follow-up after curative surgery for colorectal cancer is to identify recurrent disease at an early and possibly treatable stage. The major problem for patients with rectal carcinoma is local recurrence, which occurs in 3-30 per cent of cases and carries a 5-year survival rate of less than 5 per cent. Since 1989, in addition to digital and sigmoidoscopic examination, endorectal ultrasonography has routinely been used in the follow-up of patients with rectal cancer. Sixty-six patients (40 men) who had undergone attempted radical surgery for mid- and lower-third rectal cancer were included in the study. The mean age was 68 (range 43-87) years. A total of 190 scans were performed, with a mean of 3 (range 1-9) for each patient. Thirteen (20 per cent) of the 66 patients developed local recurrence; in all cases this was suggested by rectal ultrasonography. Digital examination and rigid sigmoidoscopy failed to detect recurrence in three patients. Four detected recurrences were treated radically; the remaining patients received radiotherapy, palliative transanal resection or laser management because of advanced age or refusal to undergo surgery. Six patients were alive a mean of 21 (range 4-50) months after recurrence. Of these six patients, four were free from disease (three had undergone salvage surgery and one radiotherapy). Postoperative rectal ultrasonography can detect some local recurrences at an early treatable stage. The method is more accurate than digital examination and sigmoidoscopy, and should be used as part of a regular follow-up programme.