CEA monitoring among patients in multi-institutional adjuvant G.I. therapy protocols

Second-look surgery for recurrent colorectal carcinoma: is it worthwhile?

Second-look surgery for recurrent colorectal carcinoma has been advocated for over four decades. Routine follow-up procedures gave way to clinically directed or carcinoembryonic (CEA)-directed procedures in the mid-1970's. In this paper, we review the results of second-look surgery for recurrent colorectal carcinoma and ask the question, "Is it worthwhile?" Excluding surgery for symptomatic patients, we conclude that second-look surgery should only be performed for recurrent colorectal carcinoma with the intent of rendering the patient disease-free. Without effective systemic therapy, "palliative" or "debulking" procedures probably do not increase survival. The most likely candidates for such a curative approach with second-look surgery are those with isolated liver, pulmonary, and, less frequently, regional recurrences.

Rapid analysis of carcinoembryonic antigen levels in gallbladder bile. Identification of patients at high risk of colorectal liver metastasis

Recently it was found that immunoanalysis of carcinoembryonic antigen (CEA) levels in gallbladder bile may be a sensitive method to detect colorectal liver metastases in humans. Methods used in the past for the detection of CEA in various body fluids were cumbersome and time consuming, requiring acid extraction, extensive dialysis, and column purification. Single-step, solid-phase radioimmunoassays, designed specifically for serum CEA analysis, were developed commercially to replace these methods. Parameters and methodology necessary to adapt these kits for Parameters and methodology necessary to adapt these kits for use with gallbladder bile are presented here. A combination of pretreatment procedures for bile, before radioimmunoassay, permit rapid, reproducible, and accurate measurement of CEA levels in gallbladder bile.

Effect of hepatic cryotherapy on serum CEA concentration in patients with multiple inoperable hepatic metastases from colorectal cancer

Eleven patients with multiple hepatic metastases from colorectal cancer, all judged inoperable, were treated by cryotherapy using a probe through which liquid nitrogen was circulated using a single freeze thaw sequence. Localization of metastases, positioning of the probe and monitoring of ice ball size was by intra-operative ultrasound. Serum carcinoembryonic antigen (CEA) was measured in these patients: there was a postoperative fall in all but two. In all but one, there has been a subsequent rise. Speed and degree of rise of CEA varied between patients. Serial CEA may be an effective means of monitoring the effect of hepatic cryotherapy.

Systematic computer-aided search of optimal staging system for colorectal cancer

Two hundred and ninety-eight patients with curatively resected colorectal cancer were classified into 12 categories according to the depth of tumour penetration (T1-T4), and lymph node status (N0-N2). Using a computer, these categories were grouped into 2-12 stages in every possible combination, so a total of 146,975 logical classifications were generated. The optimal model was selected for each group of classifications with equal stage number, thus giving the greatest prognostic information on 5-year survival according to the Akaike criterion. The results showed that (1) 13% of the total classifications, including 85% of the 3-stage classifications, were better than the Dukes system in predicting our patients' outcomes; (2) the T-level was a stage-determinant even more important than the N-level; and (3) major changes in prognosis occurred at more advanced stages than the classical "turning points". We conclude that in order to find an optimal staging of cancer, systematic computer-aided search through all the possible classifications is necessary, using the appropriate database.

[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.

Surgical resection for colorectal hepatic metastases

Hepatic resection of metastatic disease due to primary colorectal cancer provides a relatively safe and reliable method to control this otherwise fatal disease. At New York University 45 hepatic resections have been performed in 42 patients over the last fifteen years. Preoperative screening was performed by liver chemistry and intraoperative exploration in synchronous lesions and by liver chemistry, carcinoembryonic antigen, and computed tomography in metachronous lesions. Careful monitoring of fluid management, glucose utilization, and albumin requirements are essential for low postoperative morbidity and mortality. In major hepatic resections, changes in coagulation profile correlate with normalization of hepatic function as evidenced by decrease in serum bilirubin levels and increase bile production. The incidence of major operative morbidity was 17%; operative mortality was 4%. Hepatic resection gives the greatest possibility of extended survival, in our patients providing a 22% crude five year survival rate and a mean duration of survival of 33 months.

Carcinoembryonic antigen: function in metastasis by human colorectal carcinoma

Carcinoembryonic antigen (CEA) is a glycoprotein that has been useful as a tumor marker to predict recurrence in gastrointestinal malignancies, but whose biological function has not been elucidated. With the recent evidence that CEA is a member of the immunoglobulin supergene family, CEA may be involved in intercellular recognition and binding. This review examines the role that CEA plays in the development of metastases by colorectal carcinoma.

Relationship between colorectal liver metastases and CEA levels in gallbladder bile

While computerized tomographic (CT) scanning and intraoperative exploration are both considered accurate measures of liver involvement with metastatic disease, 10% to 30% of colorectal liver metastases remain undetected. Attempting to improve current methods for detecting colorectal liver metastases, CEA levels in gallbladder bile and serum from patients with known liver metastases were determined. One hundred per cent of patients with single and multiple metastases of various dimensions were observed to have gallbladder bile CEA levels strikingly higher than serum values (4.7 to 259 times greater, p = 0.0009). Linear regression analysis of estimated tumor volume and surface area versus gallbladder bile CEA levels predicted that very small tumors (less than or equal to 1 cm3 in volume) might produce detectable levels (9 to 41 ng/mL) of biliary CEA. For this reason, patients who lack clinical and radiologic evidence of distant metastases at the time of primary colorectal resection but who do have elevated gallbladder bile CEA levels (greater than or equal to 10 ng/mL) are being followed for the appearance of occult hepatic metastases.

Surrogate endpoints in clinical trials: cancer

Investigators use a surrogate endpoint when the endpoint of interest is too difficult and/or expensive to measure routinely and when they can define some other, more readily measurable, endpoint, that is sufficiently well correlated with the first to justify its use as a substitute. A surrogate endpoint is usually proposed on the basis of a biologic rationale. In cancer studies with survival time as the primary endpoint, surrogate endpoints frequently employed are tumour response, time to progression, or time to reappearance of disease, since these events occur earlier and are unaffected by use of secondary therapies. In early drug development studies, tumour response is often the true primary endpoint. We discuss the investigation of the validity of carcinoembryonic antigen (a tumour marker present in the blood) as a surrogate for tumour response. In considering the validity of surrogate endpoints, one must distinguish between study endpoints that provide a basis for reliable comparisons of therapeutic effect, and clinical endpoints that are useful for patient management but have insufficient sensitivity and/or specificity to provide reproducible assessments of the effects of particular therapies.

No-touch isolation technique in colon cancer: a controlled prospective trial

In order to assess the effect of the no-touch isolation technique, in the treatment of large bowel cancers, on the site of first recurrence and disease-free and overall survival, 236 patients were prospectively and randomly assigned to either the no-touch isolation technique (117 patients) or to a conventional resection technique (119 patients). No patient with distant metastases or unresectable disease entered the study. The two treatment groups were comparable with regard to patient characteristics. Pre- and postoperative complications (including mortality within 30 days) were similar in both groups. After a complete follow-up of 5 years, a tendency for reduction in the number of, and time to, occurrences of liver metastases was seen in the no-touch isolation group (P = 0.14). This effect was most obvious in the sigmoid colon with angio-invasive growth. Overall (P = 0.42) and corrected (P = 0.25) survival did not differ significantly among the treatment groups although in every analysis the survival data of the no-touch isolation group were superior. The data do suggest a limited benefit of the no-touch isolation technique. This observation is important since the morbidity and mortality of surgery were equal in both groups.

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.

The preoperative carcinoembryonic antigen test in the diagnosis, staging, and prognosis of colorectal cancer

A study of preoperative carcinoembryonic antigen (CEA) levels was conducted in 319 patients with surgically treated colorectal cancer, 272 of whom had disease resectable with curative intent. Only three patients could not be completely followed. All of the remaining 316 patients have been followed for a minimum of 5 years or until death. From the standpoint of diagnosis, the CEA test was more frequently positive (greater than 5 ng/ml) in patients with advanced stage disease, with larger primary tumors, and with more differentiated histopathologic characteristics. It was grossly insensitive in diagnosis of resectable cancer (26%) and was only reasonably reliable (72%) in patients with unresectable and metastatic disease. In relationship to surgical pathology of colorectal cancer, CEA levels were significantly correlated with stage of disease and with size of the primary tumor in Dukes' B lesions, but not with extent of nodal metastasis in Dukes' C lesions. In advanced stage lesions, CEA was inversely correlated with degree of anaplasia. In the overall patient group, and also among resectable patients, the preoperative CEA level was strongly associated with survival after adjustment for the effects of a number of other prognostic factors. Within stages of resectable disease, however, CEA was not significantly associated with survival among patients with Dukes' A and B lesions or Dukes' C lesions with one to three nodes involved. CEA was found to be a significant and independent prognostic determinant only in patients with Dukes' C lesions who had four or more metastatically involved lymph nodes. Under these circumstances, a preoperative CEA level could perhaps be of some value for stratification of Dukes' C patients in randomized colorectal cancer surgical adjuvant trials. The value of this test as a prognostic guide in clinical practice, however, would seem to be limited because of a lack of sensitivity in identifying individual poor prognosis patients.

Postoperative radiotherapy in Dukes' B and C carcinoma of the rectum and rectosigmoid. A randomized multicenter study

Results obtained during the first 5 years of a randomized study of postoperative radiotherapy (50 Gy) are presented. Criteria for randomization were fulfilled in 494 of 861 patients with Dukes' B and C tumors, when the trial was closed. Severe complications from radiotherapy approximated 10%. Probability of survival without local failure within 24 months was significantly higher after radiotherapy in patients with Dukes' C tumors, and the time of local failure was delayed 1 year. Patients with Dukes' B tumors had no benefit from radiotherapy. Risks of distant metastases and death were not influenced by radiotherapy in the main groups. Plasma-CEA measurements were evaluated blindly, and radiotherapy changed the critical levels of CEA for detection of recurrent cancer. It was concluded that patients with Dukes' C tumors may benefit from radiotherapy and plasma-CEA levels are influenced by radiotherapy, which may be important, when these are used in screening for recurrent cancer.

The prognostic value of the modifications of the Dukes' C class of colorectal cancer. An analysis of the NSABP clinical trials

This study was carried out in an effort to resolve the dilemma created by three proposed modifications of the Dukes' C class of colorectal cancer. Each modification is based on a separate prognostic discriminant characterized by: the level of histologically positive nodes, the depth of tumor penetration, and the number of histologically positive nodes. Data were derived from 844 patients with Dukes' C lesions randomized into two prospective clinical trials of the NSABP; the mean time on study was 41 months. Analysis of the three modifications as independent variables without regard for possible confounding effects disclosed that each had a highly significant predictive capacity. When each discriminant was examined, this time adjusting for the contribution of the other two discriminants, the effect attributable to the level of positive nodes was markedly attenuated. Thus, the level of positive nodes provided little information over and above that of depth of tumor penetration and the number of positive nodes. Of the two latter discriminants, although both were significant predictors of survival, the number of positive nodes appeared to be the strongest factor. Using both depth of penetration and the number of positive nodes, a unique Dukes' C subset of patients could be identified with a prognosis at least as good as Dukes' B lesions; this group was characterized by partial tumor penetration and the presence of 1-4 positive nodes. It is concluded that both depth of penetration and the number of positive nodes represent appropriate modifications of the initial Dukes scheme, and one discriminant should not be used to the exclusion of the other. The data raise serious doubts relative to the propriety of newly proposed TNM classification schemes that fail to utilize the number of positive nodes as a predictive discriminant.

Carcinoembryonic antigen (CEA) and alkaline phosphatase in progressive colorectal cancer with special reference to patient survival

The prognostic value of serial CEA tests was evaluated in 175 consecutive patients with progressive colorectal cancer who subsequently died of their disease. The upper normal plasma CEA limit was determined to be 8 ng/ml from serial CEA determinations in 31 patients radically operated on for colorectal cancer and observed in median 40 months without evidence of recurrence. A CEA value of greater than 8 ng/ml was highly suggestive of residual disease or recurrence, even when no clinical evidence was present. Approximately 90% of the patients dying from colorectal cancer showed an increase in CEA to greater than 8 ng/ml during the course of the disease. In 63% of the patients CEA increase preceded clinical progression or relapse, with a median time period of 4 months. Sixty-eight per cent of the patients had rising CEA values over an extended time period of many months, 14% had a preterminal increase, 13% had constantly normal and 5% constantly elevated CEA. As 6/9 patients developed a drop in CEA in relation to initiation of chemotherapy without clinical response, it is concluded that CEA is not a reliable indicator of clinical response to chemotherapy. Patients with liver metastases had higher CEA and alkaline phosphatase levels than patients with only localized disease. However, no good statistical correlation between CEA and serum alkaline phosphatase was found in patients with liver metastases (coefficient of correlation r = 0.35). An increase in CEA from normal to above 8 ng/ml predicted a decrease in survival time of median 60% counted from the time of diagnosis. The numerical CEA value was predictive of shortening of survival only when greater than 3000 ng/ml. Such high values were observed only in a minority of the patients (12%). Greater than 1000 U/l (27% of the patients) alkaline phosphatase predicted an extremely poor prognosis, with a median survival of 1 month (range 0.5-4 months). It is concluded that a rise in CEA to greater than 8 ng/ml indicates with high degree of certainty relapse or disease progression in colorectal cancer patients. CEA is not a reliable indicator of clinical response to chemotherapy, and an increase in the CEA level is of little prognostic value concerning survival. Alkaline phosphatase seems to be a more valuable predictor of a worsening of prognosis.

CEA-directed second-look surgery in the asymptomatic patient after primary resection of colorectal carcinoma

Since 1971, serial carcinoembryonic antigen (CEA) levels have been measured to monitor patients after primary resection of colorectal cancer. Based solely on a rise in CEA level above the baseline established after primary resection, 146 patients were readmitted to the hospital. Chest films, liver-spleen scan, colonoscopy, bone scan, abdominal and pelvic CAT scan, and hepatic arteriograms were performed, and elevated CEA levels were confirmed before reexploration was undertaken. In the 146 patients, 139 (95%) had recurrences, and 81 (58%) of these were resectable for potential cure. Two of the first 22 patients re-explored between 1971 and 1975 are still living 11 and 14 years after second look; of 45 patients reoperated upon from 1976 through 1979 and followed for at least 5 years, 14 (31%) are still living. A rise in CEA above the baseline established after primary resection proved to be a sensitive indicator of recurrence and prompted reexploration before symptoms developed. Early alternative therapy was begun in patients with unresectable recurrences.

Hepatic resection for metastatic colon and rectal cancer. An evaluation of preoperative and postoperative factors

Hepatic resection for metastatic colorectal cancer has been reported in over 700 patients. However, approximately 5000 patients each year are candidates for surgical excision. Since 1972, 25 patients have undergone hepatic resection for colorectal metastases at New York University. Potentially curable synchronous lesions were detected by preoperative liver chemistries and operative palpation. Patients were screened for metachronous lesions by serial liver chemistries and carcinoembryonic antigen (CEA) determinations; when clinical findings or laboratory findings were either positive or equivocal, then scanning techniques were used. Most patients had solitary lesions (20). Thirteen of 25 lesions were synchronous; 12 were metachronous. Anatomic lobectomy was performed in 13 patients (6 extended resections); and wedge resection was performed in 12. The operative mortality rate was four per cent; the 2-year survival rate, 65%; the 5-year survival rate, 25%. Hypertonic dextrose solutions were administered during and after operation. Post-operative albumin requirements ranged from 200 to 300 grams/day. Coagulation factors II, V, VII, and fibrinogen decreased after surgery to 30 to 50% of their preoperative levels. Subsequent elevation of these factors correlated with increased bile production and improvement in liver chemistries 10 to 14 days after operation. At present, hepatic resection for colorectal metastases provides the only potential method of salvage, offering a 20 to 25% long-term survival rate.

CEA tissue staining in colorectal cancer patients. A way to improve the usefulness of serial serum CEA evaluation

The evaluation of serial plasma carcinoembryonic antigen (CEA) levels is one of the most important parameter used to establish the prognosis of surgically cured colorectal cancer patients. Carcinoembryonic antigen is particularly useful in the identification of recurrences and metastasis. However, to improve the usefulness of this assay, it would be helpful to accurately determine, if possible, those patients whose cancers produce CEA. The evaluation of the presence of CEA in these cancer specimens by means of immunoperoxidase staining technique does seem to improve the sensitivity of the CEA test. Fifty-seven patients with colorectal cancer who underwent surgical treatment were studied. Tissue CEA evaluation was correlated with the plasma CEA levels, the pathologic stage and grade, and histologic type of the cancers. Results demonstrate that 66.6% of Dukes' B cancers, 78.9% of Dukes' C, and 77.7% of Dukes' D cancers stained positively for CEA by immunoperoxidase. Thirty of 57 patients with preoperative pathologic plasma CEA levels had positive tissue CEA, whereas 8/57 patients did not. Of patients with a well-differentiated cancer (G1), 81.4% had positive tissue CEA versus the 64% of G2 and 60% of G3 cancers. The authors conclude that the use of the immunoperoxidase stain to measure CEA in tissue, so that the CEA serum assay may be used in those patients known to produce CEA, results in a major increase in the sensitivity of the test.

Tissue CEA detection by immunoperoxidase (PAP) test in colorectal polyps: correlations with the degree of dysplasia

We study the presence of Carcinoembryonic antigen (CEA) on 39 colorectal polyps by the immunoperoxidase technique. The histological examination demonstrated 15 tubular adenomas, one villous adenoma, two tubulo-villous adenomas, six tubular adenomas with slight dysplasia, one tubular adenoma with moderate dysplasia, four tubular adenomas with severe dysplasia, three tubulo-villous adenomas with severe dysplasia, five tubular adenomas with neoplastic degeneration, and two tubulo-villous adenomas with neoplastic degeneration. Twenty-eight of thirty-nine polyps (71.79%) showed a positive staining reaction for CEA. Regarding the intensity of the reaction (classified as absent or negative [-], slightly positive [+], and markedly positive [+ +]), 11/39 polyps presented a negative reaction (28.21%), 19/39 (48.71%) presented a slight reaction, and 10/39 polyps (25.64%) presented a marked reaction. Results demonstrated a higher intensity of the staining reaction in severely dysplastic polyps and in neoplastic degeneration. In conclusion, it is possible that the presence of CEA can be useful to show an initial cellular restlessness of certain polyps.

Serum carcinoembryonic antigen and acute phase reactant proteins in the pre-operative detection of fixation of colorectal tumours

Fixity of colorectal tumours carries a poor prognosis, but only if it is the consequence of malignant spread. Pre-operative radiotherapy may be beneficial but selection depends on clinical examination which is often inaccurate or impossible. We therefore investigated if serum concentrations of carcinoembryonic antigen and acute phase reactant proteins (APRPS) which may be elevated in patients with colorectal cancer could determine the degree and nature of local spread prior to operation. Carcinoembryonic antigen (CEA), alpha 1 acid glycoprotein (AGP) and C-reactive protein (CRP) were measured pre-operatively in 100 patients with colorectal tumours, 89 of whom had a carcinoma. Thirty-two (36 per cent) were fixed, 18 (56 per cent) by malignancy (FM) and 14 (44 per cent) by inflammation (FI). Levels of CEA, AGP and CRP were all significantly higher in the serum of patients with fixed tumours (P less than 0.05). Concentrations of AGP greater than 1.4 g/l or CRP greater than 15 mg/l were accurate predictors of tumour fixation (specificity 87 and 90 per cent; sensitivity 78 and 78 per cent. CEA appeared more accurate in determining the nature of fixation. A value of greater than 50 ng/ml predicted 82 per cent of FM tumours (specificity 100 per cent; sensitivity 87 per cent). Thus, pre-operative measurement of serum CEA and APRP appear able to predict fixation of colorectal tumours.

Patterns of failure after surgical cure of large liver tumors. A change in the proximate cause of death and a need for effective systemic adjuvant therapy

During a period of 7 years, we have aggressively treated liver tumors whether primary or metastatic. Our experience after 43 curative major liver resections has shown an excellent overall survival: 34 of 43 patients still alive a median of 12 months after liver resection (patient ages ranged from 21 to 85 years, median 57 years). Nineteen patients underwent right hepatic lobectomy, 9 trisegmentectomy, 5 left hepatic lobectomy, 5 extended left hepatic lobectomy, 4 right lobectomy plus left lobe wedge resection, and 1 patient underwent a major hilar wedge resection. Two patients died from sepsis and hepatic failure on or before the 60th postoperative day. One patient with no evidence of recurrent colorectal cancer was lost to follow-up after 2.5 years. One patient died without cancer 12 months after left hepatic lobectomy for colon cancer metastases. Cumulative survival for the entire series and for patients after resection of colorectal cancer metastases was the same: 1 year survival 90 percent; 2 year survival 75 percent, and 3 year survival 65 percent. Seventeen of 30 patients remain disease-free after resection of liver metastases. Of the 13 who had recurrence, 8 are still alive. Ten recurrences were outside of the residual liver (predominantly multiple pulmonary metastases). One recurrence was in the right hemidiaphragm, and only three were in the residual or regenerated liver. Serial carcinoembryonic antigen analysis was the best indicator of recurrence in these 13 patients, 12 of whom were asymptomatic. These data confirm that major liver resection can be performed with minimum postoperative mortality (4.7 percent in this series). More importantly, the majority of patients were cured of their liver metastases. The next goal should be the initiation of adjuvant systemic therapy trials after liver resection in such patients.

The prognostic significance of preoperative carcinoembryonic antigen levels in colorectal cancer. Results from NSABP (National Surgical Adjuvant Breast and Bowel Project) clinical trials

This analysis explores the prognostic significance of preoperative carcinoembryonic antigen (CEA) levels in patients with colorectal cancer. The data were derived from 945 patients entered into two randomized prospective clinical trials of the National Surgical Adjuvant Breast and Bowel Project. A strong correlation was evident between preoperative CEA level and Dukes class. The mean CEA progressively increased with each Dukes category and the mean value for each of the four classes was significantly different. This relationship was prevalent whether the data were analyzed for all colorectal lesions regardless of location or specifically for right-sided colon tumors. The prognostic function of preoperative CEA level was independent of the number of positive histologic nodes. Preoperative CEA level correlated with the degree of lumen encirclement by tumor. Tumors that did not encircle more than one half the lumen were associated with significantly lower preoperative CEA levels than those that did. The presence or absence of lumen obstruction was unrelated to the preoperative CEA level. The relative risk of developing a treatment failure was associated with preoperative CEA, in both Dukes B and C patients, demonstrating that the prognostic significance of preoperative CEA was independent of Dukes class.

Adjuvant therapy of colon cancer--results of a prospectively randomized trial

After curative surgical resection, 621 patients with modified Dukes' stage B2, C1, or C2 colon carcinoma were randomly assigned to one of four treatment programs. These included chemotherapy with fluorouracil and semustine, immunotherapy with methanol extraction residue of bacillus Calmette-Guérin (BCG), combination therapy with fluorouracil, semustine, and immunotherapy, or close follow-up without adjuvant treatment. Treatment continued for 70 weeks. After a median of 51/2 years of follow-up, no significant differences were noted in either recurrence or survival rates among the four treatment programs. Leukemia developed in seven patients, all of whom had received fluorouracil and semustine. The results of this study do not support the use of chemotherapy with fluorouracil and semustine, immunotherapy with methanol extraction residue of BCG, or their combination as an adjuvant treatment program for patients at high risk for recurrent colon carcinoma. The data do, however, demonstrate the necessity for an untreated control group in a trial of adjuvant therapy for colon cancer.

Serum CEA in the follow-up of colorectal carcinoma: experience in a district general hospital

Serum CEA was measured at 6-monthly intervals, over a 3-year period, in 102 patients being followed up after apparently complete excision of colorectal carcinoma. Residual disease was identified in 27 patients and was preceded by a CEA rise in 22 of these patients (81.5%). The CEA was initially normal in 68% of patients with residual disease in whom it subsequently rose. Rise in CEA was not detected until a median of 14 weeks before recurrence was diagnosed clinically. CEA-instigated second-look laparotomy was performed in 7 patients (31.5% of cases with CEA-associated residual disease). Despite a high resectability rate, no patient was cured. The results might have been improved by more frequent CEA measurement and more immediate second-look laparotomy, but in this study, CEA rise was not associated with surgically curable residual disease.

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.

Circulating immune complexes in patients with colorectal cancer

We have attempted to better define host humoral immune response in neoplasia by quantitating serial circulating immune complex values before and after surgery in patients with primary or metastatic colorectal cancer. Circulating immune complex levels were correlated with serial carcinoembryonic antigen values and tumor courses in patients with primary resectable colorectal cancer (four patients), resectable liver metastases (three patients), diffuse liver metastases treated with regional chemotherapy (three patients), and untreated intrahepatic (one patient) and extrahepatic metastases (one patient). Circulating immune complex levels, as measured by an antigen-nonspecific assay, which utilized 4 percent polyethylene glycol insolubilization, were increased in all patients at presentation (734 delta OD450 +/- 381) when compared with normal human control sera (202 +/- 4, p less than 0.05). No particular relation was found between presenting circulating immune complex levels and tumor burden. Progressive circulating immune complex increases were demonstrated only in patients whose tumors were either completely removed or dramatically responded to regional therapy (that is, when the tumor antigen load, as reflected by the carcinoembryonic antigen value, rapidly diminished). Serum samples obtained at times of presumed antibody excess in the patients with gastrointestinal cancers were found to contain unexpectedly high concentrations of IgA. We believe these data demonstrate the kinetics of circulating immune complex change during tumor course and they have allowed us to begin to identify circulating immune complex components in patients with colorectal cancer. The results confirm our earlier findings in patients with gestational tumors and differ from accepted relations between immune complexes and tumor growth.

The detection and evaluation of human tumor metastases

Many biochemical indices are purported to have clinical utility in the detection and management of neoplasia. Experience gained during the past decade tends to indicate their having a more important role in the detection and monitoring of metastases than of the primary lesion. From this present review of some of the commoner human tumours, it is concluded that such marker substances are important adjuncts in the management of germ cell and certain endocrine and endocrine-related tumours. The carcinoembryonic antigen (CEA) provides a marker for many gastrointestinal cancers, but there are no presently available substances with clinical usefulness for either breast or lung neoplasms. Alternative approaches to the detection of metastases are also presented. The particular use of antibody probes at an immunohistochemical level has been claimed to be able to detect micrometastastic disease in bone marrow or tumour-related monoclonal antibody probes may have application to other cancers in the future.