Clinical significance of the preoperative plasma carcinoembryonic antigen (CEA) level in patients with carcinoma of the large bowel

The sensitivity and specificity of serum glycan-based biomarkers for cancer detection

Most of clinically used serum biomarkers for cancer detection were established in early 1980s when the Nobel Prize in physiology or medicine was awarded for the "discovery of the principle for the production of monoclonal antibodies." Using this "Nobel" technology, various monoclonal antibodies were obtained when different types of cancer cells were injected into mice and the ligands on the cancer cell surface were characterized. Both aberrant glycan structures and aberrant glycan-associated glycoproteins were revealed as a common feature of cancer cell surfaces through the specific interactions with the monoclonal antibodies. These results indicate that the biosynthesis of the environment-sensitive glycan structures goes awry in cancer cells, which is beyond genetic mutations. Later on, the glycan-related biomarkers were detected in the sera of cancer patients and then developed into serum biomarkers, such as CA125, CA153, CA195, CA199, CA242, CA27.29, CA50, and CA724, which are still in clinical use as of today. During the past 30 years, even with the advancement of different OMICS technologies not limited to genomics, epigenomics, proteomics, glycomics, lipidomics, and metabolomics, very few serum biomarkers have been introduced into clinical practice. The reason is that most of the newly discovered cancer biomarkers are inferior in terms of sensitivity and specificity to these biomarkers. We will summarize the reported sensitivity and specificity of currently used cancer biomarkers, especially the glycan-related biomarkers, in the forms of tables and radar plots and discuss the pros and cons of currently used cancer biomarkers.

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.

Expression and immunogenicity of NY-ESO-1 in colorectal cancer

Serum assays of NY-ESO-1 antibodies provide a guide to discriminate between patients who suffer from different types of cancer. In the present study, the expression of NY-ESO-1 was detected with the aim to identify a novel tumor antigen in colorectal cancer (CRC). Sera were obtained from 89 healthy individuals and 236 patients with CRC with stage I, II, III and IV tumors. The NY-ESO-1 autoantibody levels were determined using an enzyme-linked immunosorbent assay. The mRNA and protein expression levels of NY-ESO-1 were detected using reverse transcription-polymerase chain reaction and immunohistochemistry, respectively, in 60 CRC and paired adjacent non-tumor tissues. NY-ESO-1 antibody was detected in 40 of the 236 (16.9%) patients with CRC. The NY-ESO-1 antibody combined with carcinoembryonic antigen enhanced the sensitivity, from 52.1 to 62.7%, of the diagnosis of CRC. The frequency of antibody positivity increased with the TNM cancer stage (8.8 vs. 28.3% in stages I+II and III+IV, respectively). The mRNA and protein expression levels of NY-ESO-1 were significantly higher in CRC tissue than in adjacent non-tumor tissue. In conclusion, NY-ESO-1 is frequently expressed in CRC with the capacity of inducing a humoral immune response in CRC patients, exhibiting the potential to be a promising biomarker for CRC.

Evaluating the Prognostic Role of Elevated Preoperative Carcinoembryonic Antigen Levels in Colon Cancer Patients: Results from the National Cancer Database

OBJECTIVES

Carcinoembryonic antigen (CEA) is a reliable tumor marker for the management and surveillance of colon cancer. However, limitations in previous studies have made it difficult to elucidate whether CEA should be established as a prognostic indicator. This study examines the association between elevated preoperative CEA levels and overall survival in colon cancer patients using a national population-based registry.

METHODS

Stage I-III colon cancer patients were identified from the 2004-2006 National Cancer Database. A multivariable Cox proportional hazards model was used to estimate the association between elevated CEA levels and overall survival after controlling for important patient, hospital, and tumor characteristics. A Monte Carlo Markov Chain was used to impute the large degree of missing CEA data. All models controlled for the propensity score in order to account for selection bias.

RESULTS

A total of 137,381 patients met the inclusion criteria. Overall, 34 % of patients had an elevated CEA level and 66 % had a normal CEA level, with a median survival of 70 and 100 months, respectively. Patients with an elevated CEA level had a 62 % increase in the hazard of death (HR 1.62, 95 % CI 1.53-1.74) compared with patients with a normal CEA level.

CONCLUSIONS

Preoperative CEA was an independent predictor of overall survival across all stages. The results support recommendations to include CEA levels as another high-risk feature that clinicians can use to counsel patients on adjuvant chemotherapy, especially for stage II patients.

Watch and Wait?--Elevated Pretreatment CEA Is Associated with Decreased Pathological Complete Response in Rectal Cancer

INTRODUCTION

Between 10 and 30% of rectal cancer patients experience pathological complete response after neoadjuvant treatment. However, physiological factors predicting which patients will experience tumor response are largely unknown. Previous single-institution studies have suggested an association between elevated pretreatment carcinoembryonic antigen and decreased pathological complete response.

METHODS

Clinical stage II-III rectal cancer patients undergoing neoadjuvant chemoradiotherapy and surgical resection were selected from the 2006-2011 National Cancer Data Base. Multivariable analysis was used to examine the association between elevated pretreatment carcinoembryonic antigen and pathological complete response, pathological tumor regression, tumor downstaging, and overall survival.

RESULTS

Of the 18,113 patients meeting the inclusion criteria, 47% had elevated pretreatment carcinoembryonic antigen and 13% experienced pathological compete response. Elevated pretreatment carcinoembryonic antigen was independently associated with decreased pathological complete response (OR = 0.65, 95% CI = 0.52-0.77, p < 0.001), pathological tumor regression (OR = 0.74, 95% CI = 0.67-0.70, p < 0.001), tumor downstaging (OR = 0.77, 95% CI = 0.63-0.92, p < 0.001), and overall survival (HR = 1.45, 95% CI = 1.34-1.58, p < 0.001).

CONCLUSION

Rectal cancer patients with elevated pretreatment carcinoembryonic antigen are less likely to experience pathological complete response, pathological tumor regression, and tumor downstaging after neoadjuvant treatment and experience decreased survival. These patients may not be suitable candidates for an observational "watch-and-wait" strategy. Future prospective studies should investigate the relationships between CEA levels, neoadjuvant treatment response, recurrence, and survival.

Comparison of recurrence patterns between ≤5 years and >5 years after curative operations in colorectal cancer patients

BACKGROUND AND OBJECTIVES

To identify characteristics of recurrent colorectal cancer in terms of follow-up periods, that is, ≤5 years and >5 years after curative operations

METHODS

This study enrolled 4,023 patients. Of them, 835 patients showed recurrence after primary curative resection for colorectal cancer. Recurrence occurred ≤5 years (n = 799) or >5 years (n = 36) after curative surgery. Variables and recurrence patterns were compared between the groups.

RESULTS

Among the 835 patients who experienced recurrence, only 4.3% recurred >5 years after surgery. This group showed lower preoperative serum carcinoembryonic antigen levels, more tumors with expanding growth, well-differentiated histology, and no lymph node metastasis (all P < 0.05). In terms of haematogenous metastasis, lung or liver was the most prevalent site in patients who recurred after >5 years or ≤5 years, respectively (P = 0.005). In rectal cancer patients, recurrence patterns revealed the same results. In colon cancer patients, the liver was the most prevalent site in both groups.

CONCLUSIONS

After 5 years of follow-up, routine surveillance for detecting other malignancies seems to be sufficient. However, the possibility of late (particularly late pulmonary) recurrence should be considered. Radiologic examination to detect pulmonary metastasis should be considered in the follow-up program.

Differential expression of colon cancer associated transcript1 (CCAT1) along the colonic adenoma-carcinoma sequence

BACKGROUND

The transition from normal epithelium to adenoma and, to invasive carcinoma in the human colon is associated with acquired molecular events taking 5-10 years for malignant transformation. We discovered CCAT1, a non-coding RNA over-expressed in colon cancer (CC), but not in normal tissues, thereby making it a potential disease-specific biomarker. We aimed to define and validate CCAT1 as a CC-specific biomarker, and to study CCAT1 expression across the adenoma-carcinoma sequence of CC tumorigenesis.

METHODS

Tissue samples were obtained from patients undergoing resection for colonic adenoma(s) or carcinoma. Normal colonic tissue (n = 10), adenomatous polyps (n = 18), primary tumor tissue (n = 22), normal mucosa adjacent to primary tumor (n = 16), and lymph node(s) (n = 20), liver (n = 8), and peritoneal metastases (n = 19) were studied. RNA was extracted from all tissue samples, and CCAT1 expression was analyzed using quantitative real time-PCR (qRT-PCR) with confirmatory in-situ hybridization (ISH).

RESULTS

Borderline expression of CCAT1 was identified in normal tissue obtained from patients with benign conditions [mean Relative Quantity (RQ) = 5.9]. Significant relative CCAT1 up-regulation was observed in adenomatous polyps (RQ = 178.6 ± 157.0; p = 0.0012); primary tumor tissue (RQ = 64.9 ± 56.9; p = 0.0048); normal mucosa adjacent to primary tumor (RQ = 17.7 ± 21.5; p = 0.09); lymph node, liver and peritoneal metastases (RQ = 11,414.5 ± 12,672.9; 119.2 ± 138.9; 816.3 ± 2,736.1; p = 0.0001, respectively). qRT-PCR results were confirmed by ISH, demonstrating significant correlation between CCAT1 up-regulation measured using these two methods.

CONCLUSION

CCAT1 is up-regulated across the colon adenoma-carcinoma sequence. This up-regulation is evident in pre-malignant conditions and through all disease stages, including advanced metastatic disease suggesting a role in both tumorigenesis and the metastatic process.

Colorectal cancer biomarkers and the potential role of cancer stem cells

Over 50% of patients with colorectal cancer (CRC) will progress and/or develop metastases. Biomarkers capable of predicting progression, risk stratification and therapeutic benefit are needed. Cancer stem cells are thought to be responsible for tumor initiation, dissemination and treatment failure. Therefore, we hypothesized that CRC stem cell markers (CRCSC) can identify a group of patients whom are at increased risk for recurrence or progression of disease. If proven correct, these CRCSC biomarkers may herald a paradigm shift in the treatment of this deadly disease. This manuscript reviews current CRC evidence based screening modalities, patient stratification, and summarizes the current state of biomarkers and discusses the novel concept of putative CRCSC's as prognostic biomarkers.

Investigation of nonspecific cross-reacting antigen 2 as a prognostic biomarker in bone marrow plasma from colorectal cancer patients

Carcinoembryonic antigen (CEA) is still the only routinely used biomarker in colorectal cancer (CRC), but its utility is hampered by poor specificity and sensitivity, and the search for novel biomarkers is highly warranted. The nonspecific cross-reacting antigen 2 (NCA-2), a truncated CEA species molecule which is transcribed from the same gene, has been suggested as an alternative biomarker to CEA. In the present work, specific immunofluorometric assays were used for detection of NCA-2 and full-length CEA in bone marrow plasma from 277 CRC patients to assess their value as prognostic biomarkers, and detection was also performed in tumor tissue and a CRC cell line. Elevated plasma CEA was associated with advanced tumor stage at diagnosis and adverse patient outcome, while for NCA-2, although the same trends were observed, no additional prognostic information was gained. While specific detection of NCA-2 was clearly achieved in plasma samples, cross-reactivity with full-length CEA was observed when the antigen was exposed to common fixation chemicals. The results from this study indicate that NCA-2 is probably not a prognostic biomarker in CRC and, furthermore, underline the issue of antibody specificity when investigating CEA species molecules.

Detection of autoantibodies against Rabphilin-3A-like protein as a potential biomarker in patient's sera of colorectal cancer

BACKGROUND

Rabphilin-3A-like (RPH3AL) protein functions in the regulation of hormone exocytosis, and mutations in the RPHA3L gene have been associated with tumorigenesis in colorectal cancer (CRC). We evaluated the potential use of anti-RPH3AL autoantibodies as a marker for CRC detection.

METHODS

Sera from 84 patients with CRC and 63 healthy controls were analysed for the presence of RPH3AL autoantibodies with a Western blotting assay.

RESULTS

The frequencies of RPH3AL autoantibodies in the early stage, advanced stage and all CRC patients were 64.7%, 78.0% and 72.6%, respectively. These values are significantly higher than the frequency of RPH3AL autoantibodies in healthy controls (15.9%, P<0.001). Although the presence of RPH3AL autoantibodies did not correlate with clinical parameters, RPH3AL autoantibodies were found in 69.4% (34/49) of CRC patients who were negative for carcinoembryonic antigen. The value of the area under the receiver operating characteristic curve of RPH3AL autoantibody was 0.84, which suggests that screening for these autoantibodies could potentially be used for CRC diagnosis.

CONCLUSION

Circulating RPH3AL autoantibodies are prevalent in patients with CRC, and detection of these autoantibodies might provide a novel non-invasive approach for CRC diagnosis.

Sensitivity estimates of blood-based tests for colorectal cancer detection: impact of overrepresentation of advanced stage disease

A large number of blood-based markers have been proposed for early detection of colorectal cancer (CRC). Their sensitivity for detecting CRC has mostly been evaluated in clinical settings, and found to be higher in more advanced stages compared with earlier stages of the disease. The aim of this study is to estimate the overall sensitivity of blood-based markers expected in screening settings, where the proportion of advanced stages is typically lower than in clinical settings. A systematic literature review was performed on studies evaluating sensitivity and specificity of blood-based markers for early detection of CRC. For each study, overall sensitivity expected in screening settings was estimated by weighting stage-specific sensitivities according to the stage distribution of CRC expected in the screening setting. The latter was derived from 12,605 CRC cases diagnosed in the German screening colonoscopy program during 2003-2007. Overall, 73 studies evaluating 55 blood-based markers were identified. Adjusted sensitivity was lower than reported sensitivity in 120 (90%) evaluations of different markers. Median absolute reduction in sensitivity after adjustment was 9.0% (interquartile range: 4.0-13.0) units, whereas median relative reduction was 19.5% (interquartile range: 11.3-33.3%). Blood-based markers for CRC detection reported from clinical settings showed higher sensitivities than expected in the screening setting in most cases, mainly due to substantially higher proportions of advanced stage cancers. Adjustment of sensitivity to the stage distribution expected in the screening setting is crucial to obtain realistic and comparable estimates of sensitivities.

Comparison of carcinoembryonic antigen prognostic value in serum and tumour tissue of patients with colorectal cancer

OBJECTIVE

Carcinoembryonic antigen (CEA) in the serum and the tumour tissue of colorectal cancer (CRC) patients is the most commonly used tumour marker for the diagnosis and evaluation of prognosis or recurrence after treatment, but the role remains controversial. The objective of this study was to compare the prognostic value of CEA both in serum and tumour tissue in CRC.

METHOD

A total of 173 patients with CRC in stages I-III were retrospectively assessed with the endpoint of recurrence or metastasis after curative operation. CEA was assessed both in serum and tumour tissue.

RESULTS

37.0% (64/173) patients had a high level of CEA in serum (S-CEA) while 39.3% (68/173) had high CEA in tumour tissue (T-CEA). There were no significant differences in clinico-pathological features between the low and high S-CEA or T-CEA groups. The high S-CEA group had a worse prognosis than the low S-CEA group but the difference was not significant. The high T-CEA group had a significantly poorer prognosis than the low T-CEA group (P = 0.028) in the univariate analysis. The multivariate analysis demonstrated that the T-CEA was an independent prognosis factor in CRC. Because many factors would affect the concentration of S-CEA, there was no correlation between S-CEA and T-CEA directly.

CONCLUSION

Our study suggests that a high T-CEA concentration may be a useful and independent predictor for poor outcome after surgery in CRC patients. It may be stronger than a high preoperative serum CEA level.

Blood markers for early detection of colorectal cancer: a systematic review

BACKGROUND

Despite different available methods for colorectal cancer (CRC) screening and their proven benefits, morbidity, and mortality of this malignancy are still high, partly due to low compliance with screening. Minimally invasive tests based on the analysis of blood specimens may overcome this problem. The purpose of this review was to give an overview of published studies on blood markers aimed at the early detection of CRC and to summarize their performance characteristics.

METHOD

The PUBMED database was searched for relevant studies published until June 2006. Only studies with more than 20 cases and more than 20 controls were included. Information on the markers under study, on the underlying study populations, and on performance characteristics was extracted. Special attention was given to performance characteristics by tumor stage.

RESULTS

Overall, 93 studies evaluating 70 different markers were included. Most studies were done on protein markers, but DNA markers and RNA markers were also investigated. Performance characteristics varied widely between different markers, but also between different studies using the same marker. Promising results were reported for some novel assays, e.g., assays based on SELDI-TOF MS or MALDI-TOF MS, for some proteins (e.g., soluble CD26 and bone sialoprotein) and also for some genetic assays (e.g., L6 mRNA), but evidence thus far is restricted to single studies with limited sample size and without further external validation.

CONCLUSIONS

Larger prospective studies using study populations representing a screening population are needed to verify promising results. In addition, future studies should pay increased attention to the potential of detecting precursor lesions.

Clinical and pathologic evaluation of patients with recurrence of colorectal cancer five or more years after curative resection

PURPOSE

This study was designed to evaluate the characteristics of recurrences that occur five or more years after curative resection for colorectal cancer.

METHODS

This study included a total of 352 patients who were confirmed as having recurrence after curative resection for colorectal cancer during the period from January 1995 to December 2000. Of the 352 patients, 231 had early recurrence (less than 2 years after operation), 103 had intermediate recurrence (2-5 years after operation), and 18 had late recurrence (more than 5 years after operation). The clinicopathologic findings of the patients with late recurrence were compared with those of the other two recurrence groups, with special reference to the pattern of recurrence.

RESULTS

The rate of late recurrence was 1.2 percent. In the late recurrence group, males outnumbered females by a ratio of 3.5:1 and the mean level of preoperative carcinoembryonic antigen was 4.5 ng/ml, whereas that of the early recurrence group was 30.5 ng/ml. All the lesions in the cases with late recurrence except one lesion were located in the left colon or rectum, the tumors were small-sized and polypoid, and well-differentiated adenocarcinomas were more frequently observed. Distant metastasis, especially lung metastasis, was most frequently observed.

CONCLUSIONS

Late recurrent colorectal cancer has some characteristics compared with early or intermediate recurrence. Although recurrence at more than five years postoperatively is not common, its possibility should be considered whenever performing follow-up, and surveillance for lung metastasis is recommended after more than five years of surgery.

Tumour M2-pyruvate kinase: a gastrointestinal cancer marker

BACKGROUND

Gastrointestinal cancer tumour markers are valuable in the detection of recurrence following resection or in monitoring response to chemotherapy. CEA, CA19-9, CA-50 and CA72-4 are currently available but are nonspecific and have a low sensitivity. 'Tumour M2-pyruvate kinase' was described by Eigenbrodt around 1985. In cancers the active tetrameric form of the M2 isoenzyme of pyruvate kinase converted to an inactive dimeric form by direct interaction with oncoproteins to channel glucose carbons into DNA synthesis. This review summarizes the current knowledge of this unique tumour marker with regard to its biochemistry, assay and potential use as a diagnostic and screening tool in gastrointestinal cancer.

METHODS

A literature search was conducted for entries from 1980 to 2005 using PubMed and NeLH databases using tumour M2-pyruvate kinase, faecal tumour M2-pyruvate kinase, tumour metabolism, tumour markers and carcinoembryonic antigen as keywords. A total of 56 references relevant to tumour M2-pyruvate kinase were retrieved. Eighteen references were clinical studies involving plasma/faecal tumour M2-pyruvate kinase and gastrointestinal cancer. The remaining 38 references were clinical/nonclinical trials and reviews on tumour metabolism and plasma/faecal tumour M2-pyruvate kinase assay. Seven of the 18 clinical studies involved faecal M2-pyruvate kinase. Three of the 11 plasma tumour M2-pyruvate kinase studies were non-English language and were excluded. The sensitivity, specificity, positive predictive and negative predictive value for plasma/serum tumour M2-pyruvate kinase in the detection of gastrointestinal cancer was determined for each of the remaining eight studies. Data for gastrointestinal cancer M2-pyruvate kinase were compared with other gastrointestinal cancer markers. Data from three of the eight studies using a diagnostic cut-off value of 15 U/ml for ethylenediaminetetraacetic acid (EDTA) plasma tumour M2-pyruvate kinase were analysed together as a small meta-analysis.

RESULTS

At a diagnostic cut-off value of 15 U/ml for tumour M2-pyruvate kinase in EDTA plasma the sensitivity, specificity, positive predictive and negative predictive value was 57.3, 89, 85.7 and 64.8%, respectively, for colorectal cancers, 62.1, 89, 88 and 64%, respectively, for gastric/oesophageal cancers and 72.5, 89, 58 and 94%, respectively, for pancreatic cancers. As a faecal marker for colorectal cancers, faecal tumour M2-pyruvate kinase has a sensitivity of 73-92% at a cut-off value of 4 U/ml as against 50% sensitivity for Guaiac faecal test.

CONCLUSION

Circulating tumour M2-pyruvate kinase is more commonly elevated in oesophageal, gastric and colorectal cancer patients than conventional tumour markers. Faecal M2-pyruvate kinase is a sensitive marker of colorectal cancer. The clinical role of tumour M2-pyruvate kinase in gastrointestinal cancer management should be investigated in large-scale clinical trials.

Is it reasonable to add preoperative serum level of CEA and CA19-9 to staging for colorectal cancer?

BACKGROUND

Carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 (CA19-9) are the most common tumor markers for colorectal cancer. The aim of this study was to evaluate the possibility of adding them into the current staging system by analyzing their prognostic significance.

MATERIALS AND METHODS

The study population was patients (n = 574, 67.1 +/- 11.3 years old, 397 males) who received potentially curative resection of colorectal adenocarcinoma (stage I-III) between January 1994 and August 2002, including preoperative measurements of CEA and CA19-9. Clinicopathological characteristics and associated follow-up data were retrospectively collected by reviewing available medical charts. CEA higher or equal to 5 ng/ml was defined as abnormal (CEA+). The CA19-9 level was set at 37 U/ml (CA19-9+). Patients were further divided into four groups (1, 2, 3, 4) according to the results of these two markers (CEA/CA19-9: -/-, -/+, +/-, and +/+). Survival was analyzed for AJCC staging, CEA (+) versus (-), CA19-9 (+) versus (-), and four groups.

RESULTS

CEA and CA19-9 survival curves were not significantly different. However, the combined use of the two markers revealed a significant survival benefit (P = 0.035) of group 1 ("-" for both markers) over 4 ("+" for both) in stage II.

CONCLUSIONS

Patients with an elevated level of both CEA and CA19-9 in stage II of colorectal cancer have a significantly poorer prognosis than those with normal levels of these markers. We recommend adding both CEA and CA19-9 to the current staging system.

Carcinoembryonic Antigen as a Marker for Colorectal Cancer: Is It Clinically Useful?

Background: Carcinoembryonic antigen (CEA) is one of the most widely used tumor markers worldwide. Its main application is mostly in gastrointestinal cancers, especially in colorectal malignancy. Although in use for almost 30 years, the clinical value of CEA in colorectal cancer is still not clear.

Methods: The literature relevant to the clinical value of CEA in colorectal cancer was reviewed. Particular attention was paid to studies involving metaanalyses and guidelines issued by Expert Panels.

Results: Although of little use in detecting early colorectal cancer, high preoperative concentrations of CEA correlate with adverse prognosis. Serial CEA measurements can detect recurrent colorectal cancer with a sensitivity of ∼80%, a specificity of ∼70%, and can provide a lead time of ∼5 months. CEA is the most frequent indicator of recurrence in asymptomatic patients and currently is the most cost-effective test for the preclinical detection of resectable disease. CEA is most useful for the early detection of liver metastasis in patients with diagnosed colorectal cancer. Overall, however, little evidence is available that monitoring of all patients with diagnosed colorectal cancer leads to enhanced patient outcome or quality of life.

Conclusions: Currently, the most useful application of CEA is in the detection of liver metastasis from colorectal cancers. Because of the relative success of surgery in resecting hepatic metastases, serial determinations of the marker are recommended for detecting cancer spread to the liver. In the future, preoperative concentrations of CEA may be included with the standard staging procedures for assessing prognosis.

Clinicopathological variables and p53 overexpression as a combined prognosticator for hematogenic recurrence in colorectal cancer

BACKGROUND AND OBJECTIVE

Precise evaluation of the prognostic factors for hematogenic recurrence after resection for colorectal cancer is important not only for the prediction of patient outcome but also for the determination of adjuvant therapy. The purpose of the current study was to elucidate the clinical significance of using clinicopathological variables in combination with p53 expression as a prognosticator for hematogenic recurrence.

METHODS

One hundred forty-two patients with colorectal cancer were examined. The expression of p53 was determined by immunohistochemical staining.

RESULTS

Eighteen (60%) of the 30 patients who were positive for both p53 overexpression and lymph node metastasis, 13 (41%) of the 32 patients who were positive for p53 and venous invasion, and 13 (39%) of the 33 patients who were positive for p53 and carcinoembryonic antigen (CEA) developed hematogenic recurrence.

CONCLUSIONS

The combination of p53 overexpression and lymph node metastasis was an excellent prognostic indicator for hematogenic recurrence in colorectal cancer.

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.

Pathologic prognostic factors for gastrointestinal cancer

Numerous clinicopathologic factors have been reported to have prognostic significance for gastrointestinal cancer. Many problems, however, confront the surgeon assessing the extent of disease and the clinical and molecular pathologist distinguishing differences in tumor differentiation, behavior, and defining important prognostic markers of cancer. This review assesses current pathologic prognostic variables of gastric and colorectal cancer that have been reported to influence survival.

Optimal follow-up in colorectal cancer patients: what tests and how often?

Patients' benefit from follow-up examinations after curative surgery for colorectal cancer is unproven in spite of numerous different programs' having been designed for that purpose. Unfortunately, no final results from prospective randomized studies have been published yet and no ideal marker for recurrent cancer is available to identify patients in whom new curative treatment may be possible. So far, screening for metachronous neoplasia with intervals of several years may influence survival, whereas benefit from detecting recurrent colorectal cancer may be claimed only by using historical or other inappropriate controls. The tradition of follow-up is expensive and prospective evidence for any cost benefit is needed to justify continuous use of our limited resources in this area of patient care.

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.

Staging and surgery for colorectal cancer

Staging of colorectal cancer has become increasingly important to select groups of patients for limited or more extensive surgery, and for adjuvant radiotherapy and chemotherapy. The main treatment is still surgery, but subgroups may benefit from adjuvant therapy, even accepting additional side effects. Accurate staging is necessary to define different treatment groups. A critical review is given of the present methods of clinicopathological staging.

Prognostic factors in colorectal cancer

The prognostic power of the extent of tumour invasion is indisputable; Dukes' classification has repeatedly been proven to be strongly correlated with patient survival. Modifications have led only to confusion, resulting in caution being required in the classification of patients with Dukes' A tumours. In the UK, the American tumour node metastasis and Australian clinicopathological systems are frequently considered too complex for routine clinical use. Meanwhile, Jass's classification may be complicated by observer variation between pathologists, and recent evidence suggests that it offers no advantage over that of Dukes. All the conventional staging systems also fail to take the skill of the surgeon into account when determining outcome. Attempts at quantifying tumour structure have not heralded the expected major advance. For instance, the expense and uncertain prognostic value of tumour DNA content assessed by flow cytometry are likely to restrict widespread use of this technique. It may soon be possible, however, to provide optimum treatment for patients based on individual tumour doubling times. Classification using knowledge of how a small number of cells in the tumour have the ability to invade locally, enter blood vessels and metastasize would also provide important prognostic information on which treatment could be based. Until then, the ease of use and high prognostic power of Dukes' classification ensure that, after 60 years, it is still the 'gold standard' against which all other prognostic classifications in colorectal cancer should be assessed.

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.

Characterization of a new monoclonal antibody to a cell surface antigen on colorectal cancer and fetal gut tissues

Murine hybridoma were raised against the human colon carcinoma cell line CL-187. One clone was found to secrete a monoclonal antibody (ND-1) that recognizes a large external antigen (LEA) on human colon carcinoma cells. With indirect immunofluorescence on formaldehyde-fixed cells, more than 90% of the human colorectal carcinoma cell lines tested expressed LEA. Almost all of the 46 human noncolorectal and nonhuman cell lines tested did not express LEA, including cancer cell lines from other endodermally derived tissues. Staining of frozen sections from human colorectal tumors, noncolorectal tumors, normal adult, and normal fetal tissues showed expression of the antigen on colorectal cancer tissue, fetal colon, and fetal biliary epithelium. LEA can also be detected in the serum and ascites of colorectal cancer patients. Double indirect immunofluorescence with rabbit anti-carcinoembryonic antigen (CEA) antibody and ND-1 monoclonal antibody on a human colorectal carcinoma cell line showed that LEA is distinct from CEA. Physicochemical analysis of LEA showed that it has a large molecular weight, is resistant to extraction from the cell surface, and that sialic acid is an important component of the antigenic site. Because of the specificity for colorectal cancer tissue along with certain biochemical properties, LEA appears to be unique when compared with other tumor-associated antigens. Further research is needed to define the clinical usefulness of LEA in either the diagnosis or treatment of colorectal carcinoma.

Patient selection for adjuvant therapy trials in colorectal carcinoma

The aim of this research was to determine how to improve the efficiency of study design in adjuvant therapy trials of colorectal carcinoma. Survival analysis related to pathological variables was performed on 1020 patients who had resections for colorectal carcinoma during an 11 year complete follow-up. It was felt that the median survival of B stage patients was too long to justify their inclusion in survival trials. Practical multi-centre trials could be undertaken with patients who were found to have clinicopathological stage C. Fifty per cent of the total number of stage C patients had primary tumours with either high grade or venous invasion of mural and extra-mural veins. They had a highly significantly (P = 0.0004) poorer prognosis (median survival 27 months) than those with low or average grade and no venous invasion (median survival 49 months). The most efficient trial would select patients whose primary tumours showed lymph node involvement and high grade and venous invasion.

Detection of recurrent cancer of the colon and rectum

Outpatient follow-up in patients operated upon due to carcinoma of the colon and rectum is usually performed, due to a high rate of recurrence and with the aim of finding a curable recurrence. Due to the enormous cost of an extended follow-up system, a careful evaluation of the benefit is needed. The aim of the present investigation was to study the efficacy of the different tools in an extended follow-up. One hundred ninety patients with carcinoma of the colon and rectum were--apart from traditional clinical follow-up--followed with an extensive laboratory battery including carcinoembryonic antigen (CEA), erythrocyte sedimentation rate (ESR), hemoglobin (Hb), electrophoresis, ALP, and GT. Forty-seven recurrences were found. Thirty-one of these recurrences were first detected by a rise in CEA. Seven cases were detected at clinical follow-up and six cases due to symptoms suggestive of recurrence. The predictive value of a positive test was 79.4% for CEA but very low for the other tests studied. A negative value for any of the tests in the battery was usually accurate. Follow-up after colorectal carcinoma should include CEA as the only laboratory parameter. Postoperative colonoscopy for removal of missed synchronous lesions, chest X-ray, and endoscopic investigations of the anastomotic region also seem to be of value.

Carcinoembryonic antigen (CEA) in human colorectal cancers growing subcutaneously in nude mice

Eleven human colorectal xenografts from 26 tumor lines established in nude mice in our laboratory were investigated for carcinoembryonic antigen (CEA) production. Serum levels of CEA in nude mice were markedly elevated in all cases but one, median values ranging from 3.7 to 42.8 ng/ml. Carcinoembryonic-antigen levels for ten nontumor-bearing nude mice ranged from 0.00 to 0.12 ng/ml (median value 0.07). A clear linear correlation could be demonstrated between log CEA serum levels and log tumor volumes in serial measurements. In one case, CEA was normal in the cancer patient's serum and gave the lowest value (3.7 ng/ml) in nude mice bearing the xenograft. By the indirect peroxidase technique, CEA was localized mainly on the apical cell membranes of the cancerous glands and in necrotic areas; only small amounts were detectable in the cytoplasm. Transplantation of human colorectal carcinomas into nude mice offers an excellent experimental in vivo system to study the mechanism of release, metabolism, and excretion of the marker.

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.