Carcinoembryonic antigen and recurrent colorectal cancer

Blood CEA levels for detecting recurrent colorectal cancer

BACKGROUND

Testing for carcino-embryonic antigen (CEA) in the blood is a recommended part of follow-up to detect recurrence of colorectal cancer following primary curative treatment. There is substantial clinical variation in the cut-off level applied to trigger further investigation.

OBJECTIVES

To determine the diagnostic performance of different blood CEA levels in identifying people with colorectal cancer recurrence in order to inform clinical practice.

SEARCH METHODS

We conducted all searches to January 29 2014. We applied no language limits to the searches, and translated non-English manuscripts. We searched for relevant reviews in the MEDLINE, EMBASE, MEDION and DARE databases. We searched for primary studies (including conference abstracts) in the Cochrane Central Register of Controlled Trials (CENTRAL), in MEDLINE, EMBASE, and the Science Citation Index & Conference Proceedings Citation Index - Science. We identified ongoing studies by searching WHO ICTRP and the ASCO meeting library.

SELECTION CRITERIA

We included cross-sectional diagnostic test accuracy studies, cohort studies, and randomised controlled trials (RCTs) of post-resection colorectal cancer follow-up that compared CEA to a reference standard. We included studies only if we could extract 2 x 2 accuracy data. We excluded case-control studies, as the ratio of cases to controls is determined by the study design, making the data unsuitable for assessing test accuracy.

DATA COLLECTION AND ANALYSIS

Two review authors (BDN, IP) assessed the quality of all articles independently, discussing any disagreements. Where we could not reach consensus, a third author (BS) acted as moderator. We assessed methodological quality against QUADAS-2 criteria. We extracted binary diagnostic accuracy data from all included studies as 2 x 2 tables. We conducted a bivariate meta-analysis. We used the xtmelogit command in Stata to produce the pooled estimates of sensitivity and specificity and we also produced hierarchical summary ROC plots.

MAIN RESULTS

In the 52 included studies, sensitivity ranged from 41% to 97% and specificity from 52% to 100%. In the seven studies reporting the impact of applying a threshold of 2.5 µg/L, pooled sensitivity was 82% (95% confidence interval (CI) 78% to 86%) and pooled specificity 80% (95% CI 59% to 92%). In the 23 studies reporting the impact of applying a threshold of 5 µg/L, pooled sensitivity was 71% (95% CI 64% to 76%) and pooled specificity 88% (95% CI 84% to 92%). In the seven studies reporting the impact of applying a threshold of 10 µg/L, pooled sensitivity was 68% (95% CI 53% to 79%) and pooled specificity 97% (95% CI 90% to 99%).

AUTHORS' CONCLUSIONS

CEA is insufficiently sensitive to be used alone, even with a low threshold. It is therefore essential to augment CEA monitoring with another diagnostic modality in order to avoid missed cases. Trying to improve sensitivity by adopting a low threshold is a poor strategy because of the high numbers of false alarms generated. We therefore recommend monitoring for colorectal cancer recurrence with more than one diagnostic modality but applying the highest CEA cut-off assessed (10 µg/L).

Persistent high postoperative carcinoembryonic antigen in colorectal cancer patients--is it important?

INTRODUCTION

Evaluation of pre- and postoperative serum CEA levels together has seldom been assessed for the prognosis of colorectal cancer (CRC).

OBJECTIVE

To concurrently evaluate pre- and postoperative CEA as factors of relapse and survival.

METHODS

The study consisted of 114 patients who had undergone surgery from February 2002 to June 2006 for CRC. All patients were classified into four groups according to their pre- and postoperative CEA levels. Data obtained for clinicopathologic parameters, lymph node metastasis, stage, recurrence, and CEA levels were analyzed to determine their association with survival. Multivariate analysis by the Cox proportional hazard regression model was performed to identify the independent prognostic factors associated with survival.

RESULTS

Postoperative serum CEA levels remained high in Group 3 (n = 32). Nineteen patients (59.3%) demonstrated a detectable cause for persistent high CEA levels, while the reasons for those in the other thirteen patients (40.6%) remained obscure. Abnormal preoperative CEA levels significantly correlated with the depth of tumor invasion, lymph node metastasis, TNM stage, and recurrence (p < 0.05). Abnormal postoperative CEA levels were significantly related to the depth of tumor invasion, TNM stage, and postoperative relapse (p<0.05). Patients in Group 3 demonstrated the worst survival rate. Abnormal postoperative CEA levels, lymph node metastasis, and location of the tumor were independent prognostic factors for survival.

CONCLUSION

The survival of patients with high postoperative CEA levels due to unknown reasons may be extended if they are exhaustively tested with sensitive diagnostic methods and treated at an early stage.

Tumor marker utility and prognostic relevance of cathepsin B, cathepsin L, urokinase-type plasminogen activator, plasminogen activator inhibitor type-1, CEA and CA 19-9 in colorectal cancer

BACKGROUND

Cathepsin B and L (CATB, CATL), urokinase-type plasminogen activator (uPA) and its inhibitor PAI-1 play an important role in colorectal cancer invasion. The tumor marker utility and prognostic relevance of these proteases have not been evaluated in the same experimental setting and compared with that of CEA and CA-19-9.

METHODS

Protease, CEA and CA 19-9 serum or plasma levels were determined in 56 patients with colorectal cancer, 25 patients with ulcerative colitis, 26 patients with colorectal adenomas and 35 tumor-free control patients. Protease, CEA, CA 19-9 levels have been determined by ELISA and electrochemiluminescence immunoassay, respectively; their sensitivity, specificity, diagnostic accuracy have been calculated and correlated with clinicopathological staging.

RESULTS

The protease antigen levels were significantly higher in colorectal cancer compared with other groups. Sensitivity of PAI-1 (94%), CATB (82%), uPA (69%), CATL (41%) were higher than those of CEA or CA 19-9 (30% and 18%, respectively). PAI-1, CATB and uPA demonstrated a better accuracy than CEA or CA 19-9. A combination of PAI-1 with CATB or uPA exhibited the highest sensitivity value (98%). High CATB, PAI-1, CEA and CA 19-9 levels correlated with advanced Dukes stages. CATB (P = 0.0004), CATL (P = 0.02), PAI-1 (P = 0.01) and CA 19-9 (P = 0.004) had a significant prognostic impact. PAI-1 (P = 0.001), CATB (P = 0.04) and CA 19-9 (P = 0.02) proved as independent prognostic variables.

CONCLUSION

At the time of clinical detection proteases are more sensitive indicators for colorectal cancer than the commonly used tumor markers. Determinations of CATB, CATL and PAI-1 have a major prognostic impact in patients with colorectal cancer.

Prognostic significance of multiple molecular markers for patients with stage II colorectal cancer undergoing curative resection

OBJECTIVE

The aim of this study was to determine whether our constructed high-sensitivity colorimetric membrane-array method could detect circulating tumor cells (CTCs) in the peripheral blood of stage II colorectal cancer (CRC) patients and so identify a subgroup of patients who are at high risk for relapse.

SUMMARY BACKGROUND DATA

Adjuvant chemotherapy is not routinely recommended in patients diagnosed with UICC stage II CRC. However, up to 30% of patients with stage II disease relapse within 5 years of surgery from recurrent or metastatic disease. The identification of reliable prognostic factors for high-risk stage II CRC patients is imperative.

METHODS

Membrane-arrays consisting of a panel of mRNA markers that included human telomerase reverse transcription (hTERT), cytokeratin-19 (CK-19), cytokeratin-20 (CK-20), and carcinoembryonic antigen (CEA) mRNA were used to detect CTCs in the peripheral blood of 194 stage II CRC patients who underwent potentially curative (R0) resection between January 2002 and December 2005. Digoxigenin (DIG)-labeled cDNA were amplified by RT-PCR from the peripheral blood samples, which were then hybridized to the membrane-array. All patients were followed up regularly, and their outcomes were investigated completely.

RESULTS

Overall, 53 of 194 (27.3%) stage II patients were detected with the expression of all 4 mRNA markers using the membrane-array method. After a median follow up of 40 months, 56 of 194 (28.9%) developed recurrence/metastases postoperatively. Univariately, postoperative relapse was significantly correlated with the depth of invasion (P < 0.001), the presence of vascular invasion (P < 0.001), the presence of perineural invasion (P = 0.048), the expression of all 4 mRNA markers (P < 0.001), and the number of examined lymph nodes (P = 0.031). Meanwhile, using a multivariate logistic regression analysis, T4 depth of tumor invasion (P = 0.013), the presence of vascular invasion (P = 0.032), and the expression of all 4 mRNA markers (P < 0.001) were demonstrated to be independent predictors for postoperative relapse. Combination of the depth of tumor invasion, vascular invasion, and all 4 mRNA markers as predictors of postoperative relapse showed that patients with any 1 positive predictor had a hazard ratio of about 27-fold to develop postoperative relapse (P < 0.001; 95% CI = 11.42-64.40). The interval between the detection of all 4 positive molecular markers and subsequently developed postoperative relapse ranged from 4 to 10 months (median: 7 months). Furthermore, the expression of all 4 mRNA markers in all stage II CRC patients, or either stage II colon or rectal cancer patients were strongly correlated with poorer relapse-free survival rates by survival analyses (all P < 0.001).

CONCLUSIONS

The pilot study suggests that the constructed membrane-array method for the detection of CTCs is a potential auxiliary tool to conventional clinicopathological variables for the prediction of postoperative relapse in stage II CRC patients who have undergone curative resection.

A small rise in CEA is sensitive for recurrence after surgery for colorectal cancer

OBJECTIVE

Rise in carcinoembryonic antigen (CEA) above normal limits can indicate recurrent colorectal cancer. The aim of this study was to evaluate whether a small rise in CEA, even within normal limits was a sensitive indicator of recurrence.

METHOD

150 patients aged 22-87 years were followed up for a mean of 27 months after colorectal surgery with CEA 3 and 6 monthly computerized tomography. We analysed whether a rise in CEA > 1 ng/ml correlated with recurrence of metastases.

RESULTS

Forty-six of 139 patients in final analysis had recurrent disease. A rise in CEA > 1 had a predictive value of 74% for recurrence or metastases (sensitivity 80%, specificity 86%). These findings were similar whether or not the CEA was normal preoperatively.

CONCLUSION

If CEA is measured after surgery for colorectal cancer, a rise of >1 in the patient's postoperative value is predictive for recurrence or metastases with an overall sensitivity of 80% and specificity of 86%. Previous studies have recognized the role of large rises in CEA in predicting recurrence but this study shows that small changes in CEA may be significant even if these levels would be traditionally within 'normal' limits.

Ectopic expression of guanylyl cyclase C in CD34+ progenitor cells in peripheral blood

PURPOSE

To examine the utility of guanylyl cyclase C (GC-C)-specific nested reverse transcriptase polymerase chain reaction (RT-PCR) to detect circulating tumor cells in patients with colorectal cancer.

PATIENTS AND METHODS

Peripheral-blood mononuclear cells from 24 patients with Dukes' stage D colorectal cancer were analyzed by GC-C-specific nested RT-PCR using 1 microg of total RNA. Peripheral-blood mononuclear cells from 20 healthy volunteers served as controls. Additionally, peripheral-blood CD34+ progenitor cells were assayed for the expression of both GC-C and other epithelial cell-specific markers.

RESULTS

GC-C mRNA was detected in blood mononuclear cells from all 24 patients with colorectal cancer and all healthy volunteers. These unexpected positive results reflected low-level ectopic transcription of GC-C in CD34+ progenitor cells. Moreover, CD34+ progenitor cells expressed other epithelial cell-specific markers, including prostate-specific antigen, prostate-specific membrane antigen, carcinoembryonic antigen, CK-19, CK-20, mucin 1, and GA733.2. Limiting the quantity of mononuclear cell total RNA analyzed to < or = 0.8 microg eliminated detection of GC-C and other tissue-specific transcripts in blood of healthy volunteers. However, under the same conditions, GC-C mRNA was detected in mononuclear cells from all 24 patients with metastatic colorectal cancer. Using 0.5 microg of total RNA and GC-C-specific primers, nested RT-PCR detected a single human colon carcinoma cell (approximately 20 to 200 GC-C transcripts/cell) in 10(6) to 10(7) mononuclear blood cells.

CONCLUSION

These data suggest that GC-C may be useful for detecting circulating colorectal cancer cells. They also demonstrate that CD34+ cells are a source of ectopically expressed epithelial cell-specific markers and that CD34+ cells may contribute to the high false-positive rate generally observed when those markers are used to detect rare circulating metastatic cancer cells by RT-PCR.

Should carcinoembryonic antigen be used in the management of patients with colorectal cancer?

The contribution of carcinoembryonic antigen carcinoembryionic antigen for the effective management of colorectal cancer patients remains a controversial issue. The aim of this study is to attempt to get some valid answers to its function in the diagnosis, prognosis, and overall management of colorectal cancer patients.

METHODS

A retrospective review of colorectal cancer patients managed and prospectively registered by the authors between 1985 and 1998 was performed. Serum carcinoembryionic antigen levels were determined preoperatively in 209 patients with primary colorectal cancer and postoperatively in 196 patients who had undergone curative resection of their tumors, according to a fixed schedule. A maximum value of 5 ng/ml was accepted as being normal. With the exception of endoscopy, all other diagnostic techniques were only used after an abnormal carcinoembryionic antigen result (a raised value found twice consecutively).

RESULTS

carcinoembryionic antigen preoperative values were raised only in 40 percent of patients and were related to disease stage, with the highest values found in patients with Stage IV disease. However, an elevated preoperative carcinoembryionic antigen value had a very marked prognostic importance, with a statistically significant difference in survival curves (Kaplan-Meier); the same was valid for curatively resected patients (Stages I, II, and III) and for Stages II and III patients considered separately. Multivariate analysis using the Cox proportional hazards technique confirmed these results, showing preoperative carcinoembryionic antigen to have an independent prognostic value, with a relative risk of recurrence of 3.74 for patients with raised preoperative carcinoembryonic antigen levels. In postoperative follow-up, carcinoembryionic antigen elevation was found to be a very accurate marker of recurrence (sensitivity, 77 percent; specificity, 98 percent), mainly in liver metastasis (sensitivity, 100 percent), and the best marker of asymptomatic recurrence (63 percent of cases). However, carcinoembryionic antigen's impact on overall survival was negligible because of the poor results of surgical treatment of recurrences.

CONCLUSIONS

Preoperative carcinoembryionic antigen is a very important prognostic indicator and should be considered in future trials. Postoperative carcinoembryionic antigen elevation is a very sensitive marker of recurrence and even of asymptomatic recurrence, but its impact on overall survival does not seem to be relevant. Nevertheless, carcinoembryionic antigen should continue to be used in colorectal cancer patients until better methods of diagnosis and treatment of recurrence are developed.

Is carcino-embryonic antigen useful in the follow-up management of patients with colorectal liver metastases?

BACKGROUND

The role of carcino-embryonic antigen (CEA) in monitoring early detection of recurrent or metastatic colorectal cancer, and its impact on resectability rate and patient survival remains controversial. Our objective was to determine any association between the preoperative level of CEA and prognosis, and the resectability and survival by method of diagnosis of colorectal hepatic metastases.

METHODS

We analyzed patients who underwent exploration for hepatic resection for metastatic colorectal cancer over a 15-year period. The patient population consisted of those patients who had undergone primary colon or rectal resection and were followed up with serial CEA levels and of patients who were followed up with physical examination, liver function tests (LFTs) or computed tomography (CT) of the abdomen and pelvis that led to the diagnosis of liver metastases. Also included in the study were patients who were diagnosed with liver metastases at the time of the primary colon or rectal resection and underwent planned hepatic resection at a later time.

RESULTS

Three hundred and one (301) patients who underwent a total of 345 planned hepatic resections for metastatic colorectal cancer between January 1978 and December 1993 were included in this analysis. The median preoperative CEA level was 24.8 ng/mL in the resected group, 53.0 ng/mL in the incomplete resection group, and 49.1 ng/mL in the nonresected group (P = 0.02). More of the patients who had a preoperative CEA < or =30 ng/mL were in the resected group, while those who had a preoperative CEA >30 ng/mL were likely to be in the nonresected group (P = 0.002). The median survival was 25 months for patients with a preoperative CEA level < or =30 ng/mL and 17 months for patients with a preoperative CEA >30 ng/mL (P = 0.0005). The resectability rate and the survival of patients by method of diagnosing liver metastases-rising CEA versus history and physical, elevated LFTs, CT scan versus diagnosis at the time of primary resection-was not significant (P = 0.06 and P = 0.19, respectively). Given the nonstandardized retrospective nature of the study cohort and relative small groups of patients, the power to detect small differences in survival by method of diagnosis is limited. In the complete resection group of patients with unilobar liver disease (5-year survival of 28.8%) there was no difference in survival between those patients who had normal preoperative CEA and those who had elevated preoperative CEA, and approximately 90% of them had an abnormal preoperative serum CEA level.

CONCLUSIONS

CEA is useful in the preoperative evaluation of patients with hepatic colorectal metastases for assessing prognosis and is complimentary to history and physical examination in the diagnosis of liver metastases. Patients with colorectal liver metastases and preoperative CEA < or =30 ng/mL are more likely to be resectable, and they have the longest survival.

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.

CAM 17.1--a new diagnostic marker in pancreatic cancer

CAM 17.1-Ab is a recently described monoclonal antibody that detects a mucus glycoprotein with high specificity for intestinal mucus, particularly in the colon, small intestine, biliary tract and pancreas. We investigated the expression and release of CAM 17.1 in pancreatic carcinoma cell lines and tissue specimens of normal pancreas, chronic pancreatitis and pancreatic cancer. CAM 17.1 was weakly expressed on normal ductal cells and chronic pancreatitis, whereas it was overexpressed in pancreatic cancer. Serum analysis using a new enzyme-linked antibody sandwich assay (CAM 17.1/WGA) of patients with chronic pancreatitis, pancreatic cancer or other gastrointestinal cancer and of healthy blood donors revealed a high sensitivity (67%) and excellent specificity (90%) of CAM 17.1/WGA assay in pancreatic cancer. In comparison with the tumour marker CA19-9, the sensitivity of the CAM 17.1/WGA assay was similar to the sensitivity of CA 19-9 (67% and 76%, P = 0.22), whereas the specificity of CAM 17.1/WGA assay was higher than in CA 19-9 (90% compared with 78% in chronic pancreatitis, P > 0.05).

Pre-operative serum levels of CA 242 and CEA predict outcome in colorectal cancer

The prognostic value of the preoperative serum levels of CA 242 and CEA in patients with colorectal cancer was investigated. The serum concentrations of CA 242 and CEA were determined from preoperative serum samples of 259 patients with colorectal cancer (39 Dukes' A, 100 Dukes' B, 59 Dukes' C and 61 Dukes' D). Survival data of these patients were obtained to the end of 1993. There was a significantly longer survival in patients with a CA 242 level below 20 U/ml compared with patients with an elevated serum level. A difference was seen in overall survival (P < 0.0001), and in Dukes' B (P = 0.016) and Dukes' D (P = 0.009) stages. In Dukes' A and C colorectal cancer, the difference was not significant (P = 0.67 and P = 0.07, respectively). When 5 ng/ml was used as cut-off value for CEA, there was a significant difference in overall survival (P < 0.0001), but not within the different Dukes' stages. The prognosis was considerably worse in patients with concomitant elevation of CA 242 and CEA, compared with the prognosis of patients with normal levels or only one marker elevated (P < 0.0001). When analysing according to stage, a significant difference was seen in Dukes' B (P = 0.0004) and Dukes' C (P = 0.0007) stages. In a multivariate analysis, CA 242 was an independent prognostic factor (P < 0.0001). CEA was also an independent prognostic factor (P = 0.03), but only after exclusion of CA 242. Concomitant rise of CA 242 and CEA was found to be a strong independent prognostic factor (P < 0.0001). This study shows that the pre-operative serum CA 242 level is an independent prognostic factor in patients with colorectal cancer and that the prognosis of patients having a concomitant pre-operative elevation of CA 242 and CEA is poor.

Surgical management of locally recurrent rectal cancer

The surgical management of locally recurrent rectal cancer may involve major procedures and is not for the faint-hearted. Nevertheless, such treatment is preferable to chemotherapy and radiotherapy; the latter will fail over a period of months during which the patient is likely to experience intractable pain. Radical surgery offers good palliation and a better quality of life. Survival is prolonged by such operations which may be curative in up to one-third of patients. Nevertheless, surgeons must be realistic in their assessment of and discussions with patients.

A prospective study of six methods for detection of hepatic colorectal metastases

Many techniques are available for the identification of patients with hepatic colorectal metastases. The accuracy and clinical relevance of transabdominal ultrasound (US), computed tomography (CT), static scintigraphy, dynamic scintigraphy (HPI), intraoperative ultrasound (IOUS) and manual palpation, in the detection of intrahepatic colorectal metastases were assessed in 73 consecutive patients presenting with colorectal carcinoma; 39 were male and 34 female with a mean age of 68 years (range 43-90 years). In 33 patients either intraoperative ultrasound or palpation were omitted owing to emergency presentation (n = 14) or subsequent non-operative management (n = 19). All six investigations were completed in 40 patients. Computed tomography and hepatic perfusion scintigraphy (HPI) were the most sensitive, detecting over 90% of lesions, the others identifying approximately 80% of lesions, Specificity in all methods, apart from dynamic scintigraphy, was over 80%. Contrast-enhanced CT would appear to remain the most accurate method available. However, if the prognostic ability of HPI is confirmed on subsequent follow-up, the accuracy of HPI will rise with time, whereas that of CT will fall. Intraoperative ultrasonography took time to perform and did not alter the management of any patient within the study. We suggest that its use is limited to those patients in whom resection is contemplated, where the vascular anatomical detail provided may be invaluable.

The use of prognostic markers in surgery for colorectal cancer

The basis for prognostic prediction after surgery for colorectal cancer remains the various pathological staging systems based on that of Dukes. Serum prognostic markers have not shown significant independent prognostic power compared with these predictive tools. Much energy has been expended in examining the ability of serum markers to predict recurrent tumour prior to the onset of symptoms. Carcinoembryonic antigen (CEA) has been a particular subject of attention, and has been widely, though variably, advocated as a useful predictor in these circumstances. It has been estimated that around half a million Americans are presently undergoing regular postoperative CEA monitoring to this end. Controversy continues regarding the therapeutic utility of such monitoring. This may be resolved when the results of the only randomised trial in the field are published in the near future. No other serum marker, nor any combination of markers, has been shown clearly to be superior to CEA as a predictor of recurrent tumour.

The role of CA-242 and CEA in surveillance following curative resection for colorectal cancer

This study was undertaken to evaluate the role of a new tumour marker, CA-242, alone or in combination with CEA in the practical management of colorectal cancer patients after potentially curative resection. A cohort of 149 patients who had undergone 'curative' surgery was followed up according to an intensive protocol in order to detect recurrent disease. Over a median tumour marker follow-up period of 24 months there were 25 recurrences in 24 patients. Both CEA and CA-242 alone detected half the local recurrences. The sensitivity of CEA was 84% for distant or mixed recurrence compared with 64% for CA-242. An abnormality of either CEA or CA-242 enabled detection of five out of six local recurrences and 17 out of 19 distant or mixed recurrences with a median lead time of 5 months for each marker. Both markers were elevated concurrently in only one local and 11 distant recurrences. While CA-242 alone is not superior to CEA, their combined use (either abnormal) has a high sensitivity (88%), specificity (78%) and negative predictive value (97%); this may be useful in reducing unnecessary investigations in follow-up programmes and as a guide to the initiation of further treatment for recurrent disease.

Local recurrence of colorectal cancer: the problem, mechanisms, management and adjuvant therapy

Local recurrence of colorectal cancer after 'curative' surgery is a major clinical problem. Typically, 50-70 per cent of patients presenting to a surgical clinic will undergo apparently curative surgery for disease and of these about 10-25 per cent will develop local recurrence, in either the tumour bed or bowel wall. The wide differences in local recurrence rate both between and within institutions is probably caused by variation in surgical technique. The main causes of local recurrence are inadequate excision of the primary tumour or the draining lymph nodes, and intraoperative tumour cell implantation. The most significant single factor prognostic of local recurrence is Dukes' tumour stage. Other important factors include tumour grade and fixity, level of the tumour in the rectum, blood and lymphatic vessel invasion, inadvertent perforation of the tumour during resection, and the surgeon's experience. The prognosis of patients with local recurrence is poor. Prevention of recurrence by adequate surgery and adjuvant therapy as well as its early detection offer the best prospect of improving results.

Computerised audit for colorectal cancer

An audit has been performed of cases of colorectal cancer presenting over an 8-year period. The results of 242 patients are discussed with emphasis placed on the process of surgical audit. In particular, the ease of data handling by a computer database system is stressed. The figures produced on age, sex, presentation, diagnosis, treatment and outcome have allowed a more detailed and fruitful discussion of our practice at the monthly audit meeting.

CA 494--a new tumor marker for the diagnosis of pancreatic cancer

In 59 patients with ductal pancreatic cancer the monoclonal antibody (MAb) BW 494, which detects the CA 494 glycoprotein antigen, was analyzed in comparison with the reference tumor markers CA 19-9 and CEA. Eighty-one patients with non-pancreatic malignancies of the gastrointestinal (GI) tract, 95 with chronic pancreatitis, 124 with benign non-pancreatic GI diseases, 30 with diabetes mellitus (type I or type II) and 114 healthy blood donors served as controls. The sensitivity of pancreatic cancer was 90%, 44% and 90% for CA 19-9, CEA and CA 494, respectively. In chronic pancreatitis, as the most important control population for pancreatic cancer, the specificity was 85%, 72% and 94% for CA 19-9, CEA and CA 494, respectively.

Altered immunoglobulin A (IgA-1) levels in patients with advanced colorectal adenocarcinoma presenting with normal preoperative levels of carcinoembryonic antigen (CEA)

We investigated the value of serum IgA-1 as a complementary tumour marker to carcinoembryonic antigen (CEA) in the monitoring of the postoperative follow-up of 19 patients with advanced colorectal carcinoma presenting with normal levels of CEA. Mean follow-up period was 14 months (range 2-72 months). Mean number of serum specimens was 5 (range 2-9). IgA-1 assay employed rabbit antihuman IgA for binding IgA-1 from patient's serum and peanut agglutinin to detect the IgA-1 O-glycosidic structure. Ten patients developed distant metastases while nine patients had locoregional recurrence. All 19 patients had generally persistent elevation of serum IgA-1 throughout the follow-up period while serum CEA levels were subsequently elevated in only 10 patients. IgA-1 predicted recurrence with an average lead time of 8 months (range 1-19 months). On the other hand, mean lag time for CEA was 12 months (range 6-50 months). The data indicate the clinical utility of serum IgA-1 as a potential complementary tumour marker to CEA in the monitoring of the postoperative course of this particular subset of colorectal cancer patients.

Colorectal cancer. Principles of postoperative follow-up

Monitoring patients after primary large bowel surgery for malignancy is predicated on the concept that early detection of recurrence may provide salvage treatment for cure. Knowledge of the pathologic site and stage provides important information as to the probability of recurrence and the patterns of failure that are likely to occur. Available methods to detect recurrence include clinical, roentgenographic, and serum tests that are done more frequently during the first 2 years after surgery. Monitoring plasma carcinoembryonic antigen levels can lead to identification of asymptomatic recurrences, but there is controversy about the curability of recurrences outside the liver. Newer techniques (such as computed tomographic portography, intraoperative ultrasonography, and radioimmunoguided surgery) provide greater diagnostic accuracy and lead to more appropriate procedures during "second-look" operations. For example, hepatic resection in properly selected patients offers up to a 30% chance of cure and should be pursued aggressively. A search for metachronous cancers by endoscopy also should be done. Knowledge of the potential and patterns of failure can provide a useful guide during the postoperative follow-up care of the patient with large bowel cancer.

Evaluation of seven tumor markers (CA 50, CA 19-9, CA 19-9 TruQuant, CA 72-4, CA 195, carcinoembryonic antigen, and tissue polypeptide antigen) in the pretreatment sera of patients with gastric carcinoma

Preoperative serum levels of the tumor markers CA 50, CA 19-9, CA 19-9 TruQuant, CA 72-4, CA 195, carcinoembryonic antigen (CEA), and tissue polypeptide antigen (TPA) were measured in 94 patients with well-staged adenocarcinoma of the stomach and in 15 patients with benign gastric diseases. In all patients with carcinoma, a laparotomy was done. The serum levels were correlated with the stage of disease, the location of the primary tumor, and the resectability and grade of differentiation. The marker CA 50 was the best, with an overall positivity of 59.5%. For CA 19-9, this figure was 34%; for CA 19-9 TruQuant, 22%; for CA 72-4, 34%; for CA 195, 29%; for CEA, 33%; and for TPA, 50%. The best combination of two markers was CA 50 and TPA; this combination gave a positivity of 81%. There was no evident correlation with stage of disease and the percentage of positive serum levels or the median serum levels. The marker CA 50 gave the widest range of elevated serum levels between the cutoff level and the 90th percentile (54%). Patients with carcinoma of the cardia had higher preoperative serum levels than those with a tumor in other parts of the stomach. There was no correlation with the resectability of the tumor and the preoperative serum level. Patients with an undifferentiated tumors did not have significantly lower serum levels than those with more differentiated tumors. Currently, preoperative determination of serum tumor marker levels in patients with gastric carcinoma has no significant in clinical practice.

Carcinoembryonic antigen and carbohydrate 19-9 antigen as markers for colorectal carcinoma in children and adolescents

Colorectal cancer is rare in patients younger than 20 years of age (incidence, 1 in 10 million). Although carcinoembryonic antigen (CEA) and carbohydrate 19-9 antigen (CA 19-9) have been used widely as markers for the efficacy of therapy or detection of recurrent colorectal carcinomas in adults, no studies evaluating their efficacy in children and adolescents have been performed. Between 1986 and 1989, serial measurements of serum CEA and CA 19-9 levels were obtained from 11 patients (aged 8 to 18 years) treated at the institution of the authors. In contrast to the experience in adults, most (9 of 11) of the tumors were localized in the right or transverse colon. Histologically, 10 of 11 carcinomas were mucinous. Most patients had either Dukes' C (5 of 11) or D (5 of 11) lesions. After surgery, all patients were treated with a combination of 5-fluorouracil with Leucovorin (Lederle Laboratories, Pearl River, NY). With the use of the adult normal standards (CEA less than 3.0 ng/ml and CA 19-9 less than 37 ng/ml)6 for the patients, the specificity and sensitivity of CEA were 77% and 64%, respectively, whereas the specificity of CA 19-9 was 79% and the sensitivity was significantly low (10%). The combined specificity of the two markers was 71%, and the combined sensitivity was 60%. On the basis of these results, the authors believe that CEA and CA 19-9 are not effective markers for detection of recurrent or progressive colorectal carcinomas in children and adolescents.

Screening guidelines for colorectal cancer

A review is given of methods and results of screening for colorectal cancer in average-risk and high-risk groups. Possible methods are digital rectal exploration, endoscopic examination, barium enemas, faecal occult blood tests, tumour markers like carcinoembryonic antigen, Ca-19-9, and others, and gene markers. Final results of large randomized population studies with faecal occult blood tests are expected within the next few years, but it will probably be necessary to add flexible sigmoidoscopy to achieve a major reduction in mortality from colorectal cancer in average-risk persons. Recommendations for screening in high-risk groups are proposed, but strong support for these guidelines are still missing, an exception being first-degree relatives of individuals with familial adenomatous polyposis; the other high-risk groups include members of hereditary non-polyposis colorectal cancer families, relatives of patients with sporadic colorectal cancer, patients with colorectal adenomas, patients with previous colorectal cancer, and patients with inflammatory bowel disease.

Reoperation for colorectal carcinoma

In the management of the patient with intra-abdominal recurrence of colorectal carcinoma, surgery remains the primary mode of therapy when cure or significant palliation is anticipated. Appreciation of the importance of close follow-up after primary resection coupled with improved diagnostic modalities has allowed the surgeon not only to detect earlier recurrence but also to select the patients most likely to benefit from resection of recurrent disease. Improved surgical techniques with resultant decreases in the rates of morbidity and mortality have allowed safe hepatic resection of metastatic disease. In selected patients, this procedure produces 5-year survival rates approaching 50%. Although a clear consensus has not been reached, most studies agree that positive prognostic indicators include absence of extrahepatic disease, a small number of intrahepatic lesions, a low CEA level, and a better Dukes stage of the primary. Likewise, in the patient with recurrent disease locally, surgery provides the only means of cure and also plays a significant role in palliation. Aggressive resection with generous surgical margins in patients with contained disease may yield 5-year survival rates approaching 35%. In patients with unresectable disease and even in those with carcinomatosis, palliation can be obtained by surgical therapy. Judgment is necessary in treating these patients both preoperatively and intraoperatively. Surgical intervention for obstruction, perforation, or other anatomic or physiological compromise is often indicated and can improve the quality of life of the patient with intra-abdominal recurrence.

Characterization of the genomic organization of human carcinoembryonic antigen (CEA): comparison with other family members and sequence analysis of 5' controlling region

A cosmid containing the entire coding region for human carcinoembryonic antigen has been isolated. Detailed analysis and sequencing have determined an organization comprising nine exons encoding amino acids and one for a 3' untranslated fragment. Comparison with other family members reveals a complex pattern of homology at the 3' end of the gene. The 5' noncoding region is rich in purine-rich motifs and possible enhancer elements and has a region with properties similar to those of HTF islands.

Rectal endosonography for the visualisation of the anastomosis after anterior resection and its relevance to local recurrence

Rectal endosonography can be used to detect and localise recurrent rectal carcinoma. Distal and proximal to a rectal anastomosis the separate layers of the bowel wall as seen by rectal endosonography are well defined but at the precise level of the anastomosis separation of the layers is lost and they appear to merge. By studying histological sections of a normal anastomosis we have demonstrated that this loss of definition seen endosonographically correlates with the histological appearances. These appearances of the normal anastomosis provide a baseline image for the identification of recurrences in the region of the anastomosis.

Polyamines in colorectal cancer. Evaluation of polyamine concentrations in the colon tissue, serum, and urine of 50 patients with colorectal cancer

Total, free, and acetylated polyamine concentrations were measured simultaneously in colon tissue, serum, and urine of 50 patients with histologically proven colorectal cancer, 40 patients with nonmalignant gastrointestinal diseases, and 30 healthy volunteers. Compared with histologically unaffected colon tissue, concentrations were significantly (P less than 0.001) higher for putrescine, elevated for cadaverine, and nearly identical for spermidine and spermine in colon carcinoma, whereas N1-acetylated and N8-acetylated spermidine were detectable in cancer tissue only. Serum and urine concentrations of all polyamines except total cadaverine and spermine in serum and free spermine in urine were significantly elevated compared with healthy controls and highest sensitivity for colon cancer was found for total spermidine (89.15%) in serum and acetylputrescine (84.5%), total putrescine (84.0%), N1-acetylspermidine (79.3%), and total spermidine (92.1%) in urine. However, nonmalignant gastrointestinal diseases partly showed similar elevations which resulted in a low specificity for polyamines in colorectal cancer. Therefore, polyamines are of little value only as diagnostic markers in colorectal carcinoma. Since polyamine concentrations in serum and urine normalized in patients after curative operation while they were further elevated in patients with proven tumor relapse or metastases, these substances might play a clinical role in predicting therapeutic success or indicating relapse of the tumor. Although a significant dependency of polyamine concentrations in serum or urine to Dukes' classification, tumor localization, CEA, CA 19-9, or CA 125 did not exist, a significant linear correlation was found for tumor size.

Hepatic resection for colorectal secondaries

A postal survey of consultant surgeons in England and Wales was carried out to assess current attitudes towards screening for and treatment of hepatic metastases from primary colorectal carcinoma. The results showed that pre-, intra- and postoperative screening were inadequate. There was no consensus as to which patients would benefit from major hepatic resection for colorectal liver secondaries. Fewer than one-third of potentially operable patients underwent liver surgery.

Development of an ELISA to detect early local relapse of colorectal cancer

The Y haptenic blood group determinant is expressed on the cells of malignant gastrointestinal tumours and on the normal gastrointestinal epithelium of individuals who can secrete blood group antigens. an enzyme-linked immunosorbent assay incorporating the high affinity biotin-avidin interaction was developed to measure the serum levels of antigens bearing the Y hapten in patients with colorectal cancer. The specificity of the assays was between 88 and 93% and the sensitivity in detecting extensive disease was between 24 and 34%. However, up to 67% of patients with local or abdominal recurrent disease secreted antigens expressing the Y hapten, whereas only 30% of patients with overt hepatic metastases secreted a similar antigen. Recognition of antigens bearing the Y hapten may therefore be useful in detecting early local relapse of colorectal cancer when a second operation to excise the recurrence may be possible.

The detection and evaluation of locally recurrent rectal cancer with rectal endosonography

Eighty-five patients treated surgically for rectal cancer have been followed up by conventional clinical examination, sigmoidoscopy, and endosonography. Local recurrence was diagnosed in 22 patients. Nineteen of these had either sigmoidoscopic or digital evidence of recurrence and three were diagnosed solely by endosonography. In all cases endosonography gave additional information on which to base management decisions. Routine use of endosonography should allow the detection of early recurrence in a larger number of patients.

What can be done to improve the results in colorectal cancer?

It is seldom even under the best of circumstances that more than half the patients suffering from colorectal cancer are cured by conventional surgical management, and the results are often much worse. Attempts to improve this state of affairs have followed 4 main directions, which are here critically examined: 1. earlier (presymptomatic) diagnosis; 2. more radical surgery; 3. adjuvant radio- and chemotherapy; and 4. more meticulous follow-up using CEA monitoring and occasional "second-look" operations.