Predictive value of plasma CEA levels: preoperative prognosis and postoperative monitoring of patients with colorectal carcinoma

Aberrant cell state plasticity mediated by developmental reprogramming precedes colorectal cancer initiation

Cell state plasticity is carefully regulated in adult epithelia to prevent cancer. The aberrant expansion of the normally restricted capability for cell state plasticity in neoplasia is poorly defined. Using genetically engineered and carcinogen-induced mouse models of intestinal neoplasia, we observed that impaired differentiation is a conserved event preceding cancer development. Single-cell RNA sequencing (scRNA-seq) of premalignant lesions from mouse models and a patient with hereditary polyposis revealed that cancer initiates by adopting an aberrant transcriptional state characterized by regenerative activity, marked by Ly6a (Sca-1), and reactivation of fetal intestinal genes, including Tacstd2 (Trop2). Genetic inactivation of Sox9 prevented adenoma formation, obstructed the emergence of regenerative and fetal programs, and restored multilineage differentiation by scRNA-seq. Expanded chromatin accessibility at regeneration and fetal genes upon Apc inactivation was reduced by concomitant Sox9 suppression. These studies indicate that aberrant cell state plasticity mediated by unabated regenerative activity and developmental reprogramming precedes cancer development.

A Review of the Role of Carcinoembryonic Antigen in Clinical Practice

Carcinoembryonic antigen (CEA) is not normally produced in significant quantities after birth but is elevated in colorectal cancer. The aim of this review was to define the current role of CEA and how best to investigate patients with elevated CEA levels. A systematic review of CEA was performed, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Studies were identified from PubMed, Cochrane library, and controlled trials registers. We identified 2,712 papers of which 34 were relevant. Analysis of these papers found higher preoperative CEA levels were associated with advanced or metastatic disease and thus poorer prognosis. Postoperatively, failure of CEA to return to normal was found to be indicative of residual or recurrent disease. However, measurement of CEA levels alone was not sufficient to improve survival rates. Two algorithms are proposed to guide investigation of patients with elevated CEA: one for patients with elevated CEA after CRC resection, and another for patients with de novo elevated CEA. CEA measurement has an important role in the investigation, management and follow-up of patients with colorectal cancer.

Limitations of CEA Monitoring as a Guide to Second-Look Surgery in Colorectal Cancer Follow-Up

Forty-two patients with localized colorectal cancer (Dukes’ A, B, C stages) were treated with potentially curative surgery and controlled with a follow-up program, which included CEA monitoring, for a period ranging from 12 to 48 months (median 33 months). During this period, we observed recurrent neoplastic disease in 14 patients. A retrospective analysis of the results showed that: 1. patients with a preoperative CEA value > 20 ng/ml have a significantly higher risk of recurrence than the patients with CEA < 20 ng/ml; 2. sensitivity of the CEA test was good for metastatic recurrent disease, fairly good for residual neoplastic disease, but insufficient for local recurrence; 3. test-specificity was poor, as demonstrated by the negative results of four exploratory laparotomies performed exclusively on the basis of increased CEA levels. Since the principal aim of a second-look operation is the cure of local recurrence, this type of surgery cannot be proposed only on the basis of increased CEA levels.

Serum Levels of Carcinoembryonic Antigen, Gastrointestinal Cancer-Associated Antigen and Alphafetoprotein in Staging and Management of Patients with Advanced Carcinoma of the Stomach

Serum levels of carcinoembryonic antigen (CEA), gastrointestinal cancer-associated antigen (GICA or CA 19-9), and alphafetoprotein (AFP) were concurrently determined in patients with carcinoma of the stomach: in 84 preoperatively, and in 67 serially postoperatively. Before surgery, serum CEA gave information about the tumor load analogous to serum GICA in 69% of the patients: true-positive in 25% and false-negative in 43%; less information in 18% and more in 14%. The sensitivity of the test tended to be better in the more advanced stages, and was higher for CEA with GICA than for CEA alone or GICA alone. During follow-up, serum CEA gave information about the presence or absence of active disease analogous to serum GIC A in 78% of the patients: true-positive in 30%, true-negative in 36% and false-negative in 12%; less information in 9% and more in 13%. Neither test gave any false-positive indications. Sensitivity of the test rose from 67% for CEA alone and 60% for GICA alone to 81% for CEA with GICA. Serum AFP was elevated only preoperatively in 2% of patients. We conclude that joint application of CEA and GICA tests gave only slightly better preoperative sensitivity than CEA alone or GICA alone but proved fairly sensitive for postoperative follow-up of the patients. AFP was of little value for either purpose.

Immunohistochemical Detection of Carcinoembryonic Antigen (CEA) in Non-Cancerous and Cancerous Gastric Mucosa

Carcinoembryonic antigen (CEA) was stained by the PAP immunoperoxidase method in cancerous and non-cancerous gastric mucosa of 40 patients (25 non-cancerous dyspeptic patients and 15 patients with gastric carcinoma). The pattern of CEA localization was apical or membranous-cytoplasmic and immuno-reactivity was mild (+), moderate (++) or intensive (+++). No CEA immunoreactivity was detected in normal gastric mucosa whereas it was marked in gastric mucosa of non-cancerous dyspeptic patients with chronic atrophic gastritis and dysplasia (intense). In patients with superficial gastritis and epithelial hyperplasia it was mild or absent. The CEA localization pattern was also apical in non-cancerous dyspeptic patients with microscopic changes, e.g. superficial or chronic atrophic gastritis, epithelial hyperplasia and dysplasia, and in non-cancerous mucosa and cancerous tissue of patients with well (G1) and moderately (G2) differentiated adenocarcinoma.

Carcinoembryonic Antigen and Breast Carcinoma Antigen (CA 15.3) in Preoperative Staging and Postoperative Monitoring of Patients with Carcinoma of the Breast

Serum levels of carcinoembryonic antigen (CEA) and breast carcinoma antigen (CA 15.3) were determined in patients with breast carcinoma: in 129 before initial surgical or nonsurgical treatment and in 134 afterwards. Before any initial treatment, CEA was elevated in 15% of patients with Stage IV disease and CA 15.3 was high in 11% with Stage III and 48% with Stage IV. While monitoring management active disease was associated with elevated serum CEA in 66% of the patients, with elevated CA 15.3 in 73% and with at least one of the markers elevated in 86%. Both tests had high specificity (93% and 98%). The rise in serum CEA and, even more so, of serum CA 15.3 roughly paralleled the increase in bulk of the tumor: from locoregional disease through metastases to the lungs, bones, lungs with bones, and liver. Decreases in the levels of serum CEA and CA 15.3 reflected response to therapy, increases in the level of at least one marker - treatment failure, and levels fluctuating above the normal range indicated stationary disease.

During follow-up, the predictive value of a negative test (levels within the normal range), suggesting that the patient might be free of disease, was 61% for CEA alone, 67% for CA 15.3 alone, and 80% for the two tests combined. We conclude that an elevated serum level of only one of the markers was useful for staging, implying advanced disease. Determination of both markers jointly was useful for monitoring the effectiveness of the therapy and for follow-up aimed at detection of relapse.

The Role of Serum Carcinoembryonic Antigen (CEA) in the Management of Patients with Colorectal Carcinoma: The Experience of the Istituto Tumori of Milan

CEA determination has attained an important role in the clinical management of patients with tumors of the colorectal tract. In this paper the experience of the Istituto Tumori of Milan is reviewed and the results are discussed. Three hundred and thirty-six patients were followed after curative resection of colorectal carcinoma. The follow-up period was 15 years, from January 1975 to December 1990 (global follow-up 1358 years). In the course of follow-up 136 patients developed recurrent disease. The number of CEA determinations for each patient ranged from 1 to 37 (mean 8, total 3330). CEA levels of presurgical patients were related to the clinical stage. Among patients who developed recurrences 61% showed an increase in CEA serum levels. In 200 patients with a negative follow-up we observed only 15 cases of false-positive results.

Multiplexed cancer biomarker detection using chip-integrated silicon photonic sensor arrays

The analysis of disease-specific biomarker panels holds promise for the early detection of a range of diseases, including cancer. Blood-based biomarkers, in particular, are attractive targets for minimally-invasive disease diagnosis. Specifically, a panel of organ-specific biomarkers could find utility as a general disease surveillance tool enabling earlier detection or prognostic monitoring. Using arrays of chip-integrated silicon photonic sensors, we describe the simultaneous detection of eight cancer biomarkers in serum in a relatively rapid (1 hour) and fully automated antibody-based sandwich assay. Biomarkers were chosen for their applicability to a range of organ-specific cancers, including disease of the pancreas, liver, ovary, breast, lung, colorectum, and prostate. Importantly, we demonstrate that selected patient samples reveal biomarker "fingerprints" that may be useful for a personalized cancer diagnosis. More generally, we show that the silicon photonic technology is capable of measuring multiplexed panels of protein biomarkers that may have broad utility in clinical diagnostics.

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).

Preoperative serum levels of the carcinoembryonic antigen in hereditary non-polyposis colorectal cancer compared to levels in sporadic colorectal cancer

BACKGROUND

Carcinoembryonic antigen (CEA) serves as the most widely used and most cost-effective tumor marker in colorectal cancer for almost 30 years. Recent publications about serum CEA levels are based on patient groups without definite differentiation between hereditary and non-hereditary forms of colorectal cancer.

PATIENTS AND METHODS

We compared preoperative CEA serum levels from 105 patients with hereditary non-polyposis colorectal cancer (HNPCC) and 107 patients with sporadic colorectal cancer including influences of age and Dukes stage. CEA values in cases of HNPCC were correlated to the findings of microsatellite analyses, mutation analyses of the MMR genes (MLH1, MSH2) and respective immunohistochemistries.

RESULTS

Thirty-three HNPCC patients (31%) and 37 patients with sporadic CRC (34%) revealed elevated CEA levels higher than 5 ng/ml. The mean preoperative CEA level in all Dukes stages of HNPCC patients was lower with 31.7 +/- 180 ng/ml than in sporadic colorectal cancer with 68.3 +/- 424 ng/ml, but without significance (p = 0.72). HNPCC tumors with signs of de-differentiation (G3 and G4) revealed significantly higher CEA values with 62.2 +/- 262 ng/ml in comparison to well-differentiated tumors (G1 and G2) with 5.0 +/- 9.6 ng/ml (p = 0.02). HNPCC patients with "classical characteristics" (high microsatellite instability (MSI), MMR gene mutation, loss of MMR protein expression) had lower preoperative CEA serum levels than those without equivalent genetic alterations, but without reaching statistical significance. CEA levels of HNPCC tumors increased significantly under occurrence of metastases with mean values of 170.3 +/- 343 (p < 0.02).

CONCLUSIONS

Normal preoperative serum CEA levels do not have the same validity for all colorectal cancer patients. Low CEA levels in HNPCC patients could occur due to well-differentiated tumors and should be considered more critically than in sporadic CRC patients. Further studies including comparison of postoperative CEA development are necessary to elucidate the importance of these results.

Prognostic factors in colorectal cancer. Literature review for clinical application

PURPOSE

Identification of prognostic factors is a primary basis for planning the treatment and predicting the outcome of patients with colorectal cancer. Reviewing studies from the literature performed using univariate and multivariate analyses and their own study, the authors critically discuss the prognostic value of the clinicopathologic parameters of the tumor.

METHODS

Among 853 patients with colorectal tumors seen at the Department of Clinical Surgery of the Catholic University of Rome, Italy, 690 cases that were curatively resected the study. Overall survival rate, related to the clinicopathologic variables, was calculated, and univariate and multivariate analyses were performed.

RESULTS

Five-year and ten-year overall survival rates were 70 and 55 percent, respectively. Univariate and multivariate analyses showed that node involvement, distant metastases, bowel obstruction, and patient gender are factors independently related to outcome.

CONCLUSIONS

Data from the literature and the present study suggest that only a few clinical parameters, particularly bowel obstruction, and some pathologic factors (tumor stage, vessels invasion, and tumor ploidy) are related to patient survival rate and are the most reliable prognostic criteria. In prospective clinical studies, any other new pathologic or molecular factors should be matched with these parameters to confirm their value in outcome prediction.

Sensitivity of monoclonal antibodies to carcinoembryonic antigen, tissue polypeptide antigen, alpha-fetoprotein, carbohydrate antigen 50, and carbohydrate antigen 19-9 in the diagnosis of colorectal adenocarcinoma

PURPOSE

This study was designed to establish the sensitivity of monoclonal antibodies to carcinoembryonic antigen (CEA), alpha-fetoprotein (AFP), tissue polypeptide antigen (TPA), carbohydrate antigen 50 (CA 50), and carbohydrate antigen 19-9 (CA 19-9) and the efficacy of the joint determination of several tumor markers, as well as the dynamics of postoperative normalization of each marker in the absence of recurrence.

MATERIALS AND METHODS

A prospective study was carried out in 100 patients subjected to surgical resection of colon adenocarcinoma. Serum concentrations of these markers were determined the day before surgery and seven days, two months, and six months after surgery.

RESULTS

The results demonstrate that sensitivity increased as the disease spread and that CA 19-9 was the most sensitive tumor marker. The rate of false negatives was 40 percent for Dukes Stage A lesions, 19 percent for Dukes Stage B, 7 percent for Dukes Stage C, and 0 percent for Dukes Stage D. Determination of two markers (CA 19-9 and CEA) provided the greatest sensitivity in Stages A and D tumors (60 percent and 100 percent, respectively); the incidence did not change when measurements of other antigens were associated. For Stages B and C, determination of at least three markers was necessary, the association of CEA, TPA, and CA 19-9 being that which showed the greatest sensitivity, 78 percent and 91 percent, respectively.

CONCLUSIONS

It would be advisable to include monoclonal antibody determination of CEA, TPA, and CA 19-9 in the diagnosis of adenocarcinoma, despite the fact that ultimate sensitivity will depend on the degree of tumor extension or on the presence of metastasis.

Biologic evaluation of tumor-associated glycoprotein-72 and carcinoembryonic antigen expression in colorectal cancer, Part I

Tumor-associated glycoprotein-72 has been recently suggested as a new serum marker for colorectal cancer. In fact, approximately 40 percent of colorectal cancer patients have positive tumor-associated glycoprotein-72 serum levels at the time of diagnosis, while only 3 percent of patients with benign diseases are positive. A longitudinal evaluation of colorectal cancer patients suggested the utility of combining the measurement of tumor-associated glycoprotein-72 with that of carcinoembryonic antigen to monitor disease status not only at the time of diagnosis, but also at the time of recurrence. Several reports have indicated that the expression of some tumor antigens in colorectal adenomas may correlate with those parameters conventionally considered as indicative of malignant transformation. The presence of tumor-associated glycoprotein-72 in colorectal adenomas has been recently correlated with preneoplastic lesions, suggesting that tumor-associated glycoprotein-72 may be considered as an early marker of neoplastic transformation. The evaluation of tumor antigens can be considered a new tool in the management of colorectal cancer.

The clinicopathologic features of serum CA 19-9-positive colorectal cancers

The preoperative serum levels of carbohydrate antigen 19-9 (CA 19-9) were determined in 206 patients with colorectal cancer, 52 (25.2%) of whom were found to be positive. All of these patients had advanced cancers and significantly higher incidences of tumor invasion through the muscularis propria (91.3%) and lymph node involvement (54.5%). The incidences of liver metastasis and Dukes' stage D in the CA 19-9-positive group were 38.5% and 42.9%, respectively, significantly higher than those in the CA 19-9-negative group of 6.5% and 14.8%, respectively. Moreover, the incidence of liver metastasis in the CA 19-9-positive group patients with Dukes' stage D cancer was 95.2% (20/21); CA 19-9 showing higher specificity (81.7%) and a more positive predictive value (38.5%) for liver metastasis than the carcinoembryonic antigen (CEA). When a cutoff value of 160 U/ml was used, the specificity and positive predictive value reached 97.7% and 81.0%, respectively. An analysis of response operating characteristic (ROC) curves for liver metastasis revealed that CA 19-9 was more useful than CEA. The long-term survival of the CA 19-9-positive group patients was significantly worse than that of the CA 19-9-negative group patients (P < 0.0001), with no 1.25-year survivors in the former group when the cutoff value of 160 U/ml was used. These results suggest that serum CA 19-9 as a useful preoperative indicator of liver metastasis and prognosis in colorectal cancer.

Tumor-associated glycoprotein-72 serum levels complement carcinoembryonic antigen levels in monitoring patients with gastrointestinal carcinoma. A longitudinal study

Eighty-two patients diagnosed with gastrointestinal (GI) adenocarcinoma were evaluated before and for 26 months after primary tumor resection for the presence of two serum tumor markers: tumor-associated glycoprotein-72 (TAG-72) and carcinoembryonic antigen (CEA). Elevated TAG-72 and CEA serum levels were found preoperatively in 32 (39%) and 34 (41.5%) of the 82 patients, respectively. The percentage of patients with elevated serum levels of either TAG-72 or CEA was 56.1% (46 of 82). Twelve (15%) patients who had normal CEA serum levels had elevated TAG-72 serum levels, and conversely, serum from 14 (17%) patients who were TAG-72 negative were CEA positive. Forty-five of the 82 patients were diagnosed with advanced disease (i.e., Stages C and D for colorectal, Stages III and IV for stomach), and 29 (64.4%) and 26 (57.8%) of those patients had elevated serum levels of TAG-72 or CEA, respectively. Elevated levels of either TAG-72 or CEA, however, were found in sera of 82.2% of patients with advanced GI cancer, which is an increase of 24.4% over the use of CEA antigen alone as a marker of disease. The measurement of both TAG-72 and CEA may improve the diagnosis of patients with GI malignant disease due to the apparent complementary association which exists between these tumor markers. Serum TAG-72 and CEA levels were monitored in 31 patients for varying lengths of time after resection of the carcinoma; 11 patients developed recurrent disease. Sera from nine of 11 (81.8%) of these patients had elevated TAG-72 levels and six of 11 (54.5%) had elevated CEA levels. Tumor marker elevations were observed either before (35 to 166 days) or at the time of diagnosis of recurrence. The elevation of one or both markers correlated with the clinical status in ten of 11 (90.9%) patients with recurrence. In addition, 20 patients who were clinically free of disease after more than 700 days' follow-up had normal serum levels of both TAG-72 and CEA. These findings suggest that the combined use of serum TAG-72 and CEA measurements may improve detection of recurrence in patients with GI cancer and may be useful in the postsurgical management of GI adenocarcinoma patients.

Tumor markers in cancer of the colon and rectum

The primary role that tumor markers for cancer of the colon and rectum have at this time is for postoperative surveillance of those patients resected for cure who are at risk for recurrence of the disease. Carcinoembryonic antigen (CEA) serum levels are followed by most surgeons prospectively after the potentially curative resection. This tumor marker has not been advocated as a screening test for these cancers; however, a preoperative CEA serum level is determined in those patients before the initial surgery for colon or rectal cancer. The serum level of CEA is mainly determined by tumor differentiation and stage of disease. If the CEA serum level begins to increase during the postoperative surveillance period, the recurrence of colon or rectal cancer must be suspected. Further investigations are then performed to identify the location and resectability of the recurrent disease. Monoclonal antibodies labeled with radioisotope are presently being used clinically to identify recurrence of colon and rectal cancer. Used in conjunction with elevated serum CEA levels (or other determinants of recurrent disease) these tumor markers can specifically identify site(s) of cancer recurrence. Theoretically, by attaching cancer-fighting agents (i.e., chemotherapeutic agents) to the monoclonal antibody, the site of tumor recurrence can be potentially treated, too. Hence, these "tumor-seeking missiles" may one day be used to treat cancer recurrence.

Clinical evaluation of serum tumor-associated glycoprotein-72 as a novel tumor marker for colorectal cancer patients

A novel tumor marker, tumor-associated glycoprotein-72 (TAG-72), has been identified using monoclonal antibody (MAb) B72.3. Using immunohistochemical techniques, TAG-72 has been found in carcinomas of various origin including colon, stomach, breast, lung, prostate, and ovary, as well as in body fluids. The presence of TAG-72 in serum samples from 260 patients with colorectal disease (malignant or benign) has been evaluated using the CA72-4 assay. Approximately 40% of patients with colorectal cancer exhibit elevated levels of this marker; moreover, the presence of positive levels of TAG-72 significantly correlates with advanced stages of disease, suggesting that TAG-72 may be a good marker of advanced colorectal cancer. Only 2% of the patients diagnosed with colorectal disease had elevated TAG-72 serum levels indicating the high specificity of this marker. A comparative study with carcinoembryonic antigen (CEA) serum levels showed a complementarity of the two tumor markers; in fact, 49.6% of CEA negative cases scored positive for TAG-72. A longitudinal evaluation of TAG-72 serum levels in 31 patients with malignant disease was performed. The results indicate that patients with increasing TAG-72 serum levels postoperatively may be indicative of recurrent disease. In 60% of patients in which significant changes of CEA levels could not be detected, TAG-72 showed rising positive levels prior to clinical evidence of recurrent disease. These results suggest that the simultaneous use of TAG-72 and CEA serum markers may be useful in the diagnosis of recurrent disease and therefore play an important role in the clinical management of cancer patients.

[The significance of the preoperative CEA value for the prognosis of rectal cancer]

254 patients were operated for rectal carcinoma in the period from 1980 to 1986. The number of curative procedures, recurrence rate and 5-year-survival rate were dependent on the preoperative CEA levels, which correlated with the tumour stage. Even within tumour stages with enough cases for statistical evaluation the CEA could be established as an independent prognostical variable. Within stage pT2N0M0 recurrence rate for patients with preoperative CEA level below 5 ng/ml was 29% compared to 64% in patients with higher serum levels. Median survival time for the two groups were 65 and 35 months, respectively. In stage of lymph node involvement median survival times of 46 and 25 months were observed for the groups with CEA levels above and below 5 ng/ml. The pattern of recurrence within the two stages seemed to be unaffected by the preoperative CEA level. Patients with preoperative elevated CEA represent a risk group with need of consistent postoperative follow-up and CEA controls.

The levels of alpha 1-antitrypsin and alpha 1-antichymotrypsin in the sera of patients with gastrointestinal cancers during diagnosis

Protease inhibitors, such as alpha 1-antitrypsin (A1AT) and alpha 1-antichymotrypsin (A1AChy) have been considered in searching for new biochemical tumor markers useful at initial diagnosis, staging, and monitoring of cancer diseases after surgery. Levels of both antiproteases in serum of 32 patients with gastric cancer and 61 patients with colorectal cancer at initial diagnosis were studied. A significant increase of A1AT and A1AChy was found in the initial stages of both cancer groups as compared to healthy blood donors. A significant correlation between A1AT and A1AChy serum level and cancer stages was observed. The antiprotease serum concentrations progressively increased with increasing severity of gastric and colorectal cancers. The A1AChy level correlated with the histologic grade of both cancers and were higher in Grade III than in Grade II. These findings could be useful in the early diagnosis of gastric and colorectal cancers and in complex preoperative diagnostic procedure to estimate the stage of disease.

[Effect of serial CEA determination on diagnosis, therapy and prognosis of recurrent colorectal cancer]

A rising CEA level did not indicate an early tumour recurrence in the follow-up of 660 patients with curative surgery because of colorectal carcinoma. In case of rectal carcinoma the first rise of the tumour marker preceded diagnosis of recurrence by other means 7.9 months on an average, in case of colonic carcinoma 5.1 months. The long-term survival after secondary procedure was 17.5% for patients with normal CEA value at time of reoperation and surmounted life expectancy of patients with rising tumour-marker level significantly (5.9%). The worst prognosis was found for the collective with rising CEA before diagnosis of relapse by other means, none of whom was saved by reoperation. The resectability rate of metastases was higher than that of local recurrences with nearly identical survival for both groups. Because of the long CEA lead times advances in therapy by second-look procedures are to be expected mainly for patients with pelvic recurrences after abdominoperineal extirpation.

Tumour markers in colorectal cancer

Carcinoembryonic antigen (CEA) is still the best marker both for primary diagnosis and post-treatment monitoring of patients with colorectal cancer. Monoclonal antibodies, especially CA 19-9 and CA 50 may give additional information whereas CA 125 seems to be of no value in patients with colorectal cancer. The sensitivity of CEA determination for Dukes' A carcinomas is as low as 30%, but increases to 85% for Dukes' D carcinomas. The best clinical benefit of CEA is in postoperative monitoring of surgically treated patients with colorectal cancer. The sensitivity and specificity for distant metastases are 85%. The sensitivity in the detection of local recurrence is low (40%) but the specificity is still high (80%). A high CEA level postoperatively strongly suggests either local recurrence or disseminated disease, but a negative value does not exclude their presence. If CEA is negative both preoperatively and one month postoperatively, CA 19-9 or CA 50 may be used in the monitoring of these patients.

Efficiency of composite tests in gastrointestinal cancer. Preoperative prediction of liver metastases by scintigraphy, alkaline phosphatase, and carcinoembryonic antigen

The efficiency of composite tests (liver scintigraphy, serum alkaline phosphatase, and serum carcinoembryonic antigen) in finding or excluding liver metastases preoperatively was evaluated in 185 surgical patients with high probability for gastrointestinal cancer--142 with colorectal and 43 with gastric disorders. A pathoanatomic verification procedure showed liver metastases in 21 and 7 patients, respectively. For each test two cut-off levels were defined in accordance with the operational purpose of the test: either to diagnose metastases (no false-positive test results) or to exclude metastases (no false-negative test results). Generally, composite tests increased overall efficiency; in the colorectal group 39% of the patients were correctly classified by the combined, triple test; in the gastric group 94% were correctly classified. In conclusion, we think composite tests are useful, and the operational approach described may be helpful in decision-making and test evaluation.

Comparing predictive decision rules in postoperative CEA monitoring

To evaluate the usefulness of serial postoperative carcinoembryonic antigen (CEA) assays, seven previously published decision rules for predicting tumor recurrence were compared retrospectively using CEA values from 214 patients followed 36 to 120 months after surgery for colorectal carcinoma. Decision rules employing cutoff values to predict tumor recurrence were found inadequate for the asymptomatic patient. This attenuation of prognostic usefulness appeared attributable to inadequacies of CEA assays for predicting late recurrences. From these analyses, elevated CEA results without other objective evidence might be insufficient to justify second-look surgery. In addition, late recurring tumors tended not to cause elevated CEA levels.

Value of serum levels of carcinoembryonic antigen, CEA, and gastrointestinal cancer antigen, GICA or CA 19-9, for preoperative staging and postoperative monitoring of patients with colorectal carcinoma

Serum levels of gastrointestinal cancer antigen (GICA) and carcinoembryonic antigen (CEA) were determined in 167 patients with colorectal carcinoma. Eighty-eight patients were studied preoperatively, and 79 postoperatively, before, at the time of, and after the diagnosis of relapse. The authors aimed to assess how often the GICA test failed, i.e., was false-negative in patients in whom the CEA test was true-positive and, more importantly, whether it could give diagnostic information in patients in whom the CEA test failed. Before surgery, serum GICA gave similar information to serum CEA in 56 percent of the patients: true-positive in 18 percent and false-negative in 38 percent; less information in 42 percent; and more information in only 2 percent. During the postoperative follow-up, serum GICA gave similar information to serum CEA in 55 percent of the patients: true-positive (i.e., rising persistently from a postoperative nadir) in 27 percent and false-negative in 28 percent; less information in 44 percent; and more information in only 1 percent. Therefore, this test in its present version, where both the catcher and the tracer antibody are the same, NS 19-9, is redundant.

Role of carcinoembryonic antigen assay in the management of cancer

CEA is a molecule produced by a large number of malignant and benign tissues. Measuring levels of CEA circulating in the blood by radioimmunoassay can be used in the management of cancer patients. Because of high false positive and false negative percentages in normal populations, it has not been useful in screening for malignancy. However, in several types of cancer patients the test has been shown to be of considerable clinical value. Elevated CEA levels indicate a poor prognosis in patients with primary colorectal cancer, primary pancreatic cancer, primary breast cancer, and primary lung cancer. Serial CEA titers obtained following cancer treatments can be used to monitor the therapy. CEA can assess the adequacy of surgical removal of a primary colon or rectal cancer, monitor responses to chemotherapy, and assess response to radiation therapy. The greatest clinical impact of CEA has been in the detection of recurrent colon or rectal cancer following surgical resection of the primary malignancy. Early detection of recurrence, when combined with reoperative second-look surgery, may result in 30% long-term survivors.

Follow-up of patients with colorectal cancer

In our follow-up study of 65 patients after curative surgery for colorectal cancer, tests other than history and physical examination detected only two cases of potentially curable recurrent colorectal cancer. As a routine follow-up test, carcinoembryonic antigen determination is preferable to computerized tomographic scanning, since the sensitivity and specificity of carcinoembryonic antigen and computerized tomographic scanning were found to be equivalent and carcinoembryonic antigen is much less expensive. There was no benefit to the routine use of liver function tests or chest roentgenograms during follow-up. Since barium enema contributed little to what colonoscopy accomplished with greater comfort to the patient, barium enemas should be used only when colonoscopy is not totally successful in reaching the cecum. The most beneficial aspect of the follow-up of these patients is probably the elimination of future metachronous lesions by removal of small, benign polyps.

Multivariate analyses as aids to diagnosis and assessment of prognosis in gastrointestinal cancer

The role of carcinoembryonic antigen (CEA), gamma glutamyl transpeptidase (gamma GT), phosphohexose isomerase (PHI), pseudouridine (psi) and acute phase reactant proteins (C-reactive protein (CRP) alpha 1-antichymotrypsin (ACT) and alpha 1-acid glycoprotein (AGP] in assessing the prognosis of gastrointestinal neoplasms and the discriminant function in distinguishing benign from malignant diseases of the GI tract was examined. In stomach cancer pre-operative levels of CRP can help in the identification of the patients with a resectable tumour; the pre-operative biochemical measurements do not give any further information on prognosis once stage and site are taken into account. In colorectal cancer pre-operative ACT levels give additional prognostic information once the clinical factors, Dukes stage, sex and age have been accounted for; PHI levels are on the border line of significance. A discriminant function has been devised using sex, CEA, psi, gamma GT, ACT and PHI that can identify 89% of Dukes "D" patients prior to surgery with a misclassification of 7% of other cases of colorectal cancer. A discriminant function using all the biochemical variates separated the cancer from non-cancer patients. The false positive rate for cancer was 16% and a false negative rate of 19%, when the cut-off level was set at 0.7.

Is CEA analysis of value in screening for recurrences after surgery for colorectal carcinoma?

The progress of 139 patients operated upon for cure of colorectal carcinoma, was followed postoperatively with a standardized protocol. A CEA test was performed for comparison with other parameters. Median observation time was four years. When an upper limit for CEA of 7.5 micrograms/1 was allowed, sensitivity was found to be 78 per cent, specificity 91 per cent, and predictive value of an elevated CEA concentration, 83 per cent. In general, CEA measurement traced recurrence six months before clinical diagnosis. In only a few cases was recurrence first heralded by an abnormality in other blood chemistry test results. CEA may thus be used in postoperative screening for recurrence even though most recurrences, when detected, are not curable.

The strongest prognostic factors in colorectal carcinoma. Surgicopathologic stage of disease and postoperative fever

Of 227 patients with stage B or C colorectal carcinoma operated for "cure," 132 had a febrile postoperative course. Of the latter, five patients (3.7 per cent) died of sepsis. The five-year actuarial recurrence rate for 227 patients was 53 per cent. When the patients were divided into groups according to stage of disease and postoperative fever, the following was found: Eighty-one low stage patients (B1 + B2) had a 34 per cent five-year actuarial recurrence rate, and 146 high-stage patients (B3 + C4 + C2)-- a 71 per cent rate (P less than 0.0005). Fever occurred postoperatively in 46 per cent of low-stage patients and in 65 per cent of high-stage patients (P = 0.004). In low-stage patients, the five-year actuarial recurrence rate was 3 per cent in the group with an afebrile postoperative course, and 66 per cent in that with fever (P much less than 0.0005). Similarly, in high-stage patients, the recurrence rate was 24 and 93 per cent, respectively in the group with afebrile and febrile postoperative courses (P much less than 0.0005). Preoperative plasma CEA levels seemed to have no bearing upon prognosis, unless above 20 ng/ml. Eighty-two per cent of patients who had serial postoperative plasma CEA measurements and recurrence of cancer had increasing CEA levels. Thus, postoperative fever lasting two or more days was the most unfavorable prognostic factor, highly significant statistically, whereas stage of disease ranked only second in isolating better prognoses among operated patients from those at higher risks of recurrence.

Serial CEA assays and liver scintigraphy for the detection of hepatic metastases from colorectal carcinoma

Of 340 patients with histologically proven colorectal carcinoma, hepatic metastases were diagnosed in 90 (26 per cent), in 50 at the time of initial surgery (synchronously) and in 40 during the post-operative follow-up (metachronously). At the time of initial surgery, plasma carcinoembryonic antigen (CEA) levels were markedly elevated in patients with synchronous metastases and normal or only moderately elevated in those with metachronous metastases. During follow-up, CEA levels in the entire group of patients with metastases remained normal in 8 per cent and rose in the remainder: very quickly in 85 per cent and slowly in 15 per cent. Hepatic metastases were diagnosed by strict scintigraphic criteria in 70 per cent of patients and were suggested by liberal criteria in the remainder. During follow-up, hepatic metastases progressed in the scintigraphic image from those defined by liberal to those diagnosed by strict criteria. In two-thirds of the patients, liver scintigraphy proved to be superior to the CEA test in diagnosing hepatic metastases by strict criteria; in the majority of the remainder of patients, the CEA test, particularly in cases with a pattern of fast increase of CEA in plasma, suggested metastases before a definite diagnosis could be made by liver scintigraphy. In only 3 per cent of the patients neither liver scintigraphy nor the CEA test were indicative of metastases. Thus, the two diagnostic modalities, when combined, could attain a sensitivity of 97 per cent, when patients with persistently rising CEA levels and concomitant liver lesions defined by the liberal criteria were grouped with those for whom scintigraphy was unequivocal.