Clinical significance of the number of positive tumor markers in assisting the diagnosis of lung cancer with multiple tumor marker assay

Distribution of the Carbohydrate Antigens, Du-Pan-2 and Ca19-9, in Tumors of the Lung

Aims and background

The carbohydrate chains of malignant cells appear to be related to oncofetal differentiation. The serum levels of CA19-9 have been reported to be evaluated in some patients with lung carcinomas, however, the distribution of carbohydrate antigens were not precisely described. We have investigated in this study the distribution of DU-PAN-2 and CA19-9 antigens in lung tumors.

Methods

Ninety five specimens of lung tumors were selected from surgical specimens. The expression of DU-PAN-2 and CA19-9 were studied by immunohystochemical techniques. The relationship between the expression of these antigens and the classification or the differentiation degree of the tumors were examined.

Results

DU-PAN-2 or CA19-9 antigens were detected in 41 (54%) and 45 (59%) cases of the 76 malignant epithelial tumors investigated. These antigens were detected in all types of malignant epithelial tumors, including squamous cell carcinomas, where they were mainly localized to the entire cell surface of malignant cells. In adenocarcinomas, large cell carcinomas and small cell carcinomas, however, these antigens were commonly detected both on the cell membrane and in the cytoplasm. There was positive correlation between the degree of differentiation and DU-PAN-2, but not CA19-9 expression. Among the non-epithelial tumors investigated, those antigens were detected in pulmonary blastomas but not in mesotheliomas.

Conclusions

Immunohistochemical studies for DU-PAN-2 and CA19-9 are useful for defining characteristics of the lung tumors. DU-PAN-2 could be a marker for differentiating between malignant epithelial tumors and mesotheliomas.

Cyfra 21–1 in Lung Cancer: Comparison with Cea, Ca 125, Scc and Nse Serum Levels

CYFRA 21–1, CEA, CA 125, SCC and NSE serum levels were determined in 50 healthy subjects and in 189 patients with primary lung cancer (101 with locoregional disease, 68 with recurrence and 20 patients with no evidence of residual disease (NED). Abnormal CYFRA 21–1 serum levels were found in 53.6% (90/168) of the patients with active cancer. Neither healthy subjects nor NED patients had abnormal serum levels. CYFRa 21–1 serum concentrations were significantly higher in patients with active cancer than in healthy subjects or in NED patients (p < 0.0001). CYFRA 21–1 sensitivity was related to tumor histology with abnormal levels in 64.7% of patients with NSCLC and in 30% of patients with SCLC (P <0.0001). In NSCLC, serum CYFRA 21–1 concentrations were also related to histological type, the highest values being found in squamous cell carcinomas and LCLC and the lowest in adenocarcinomas (p < 0.04). There was also a clear relationship between CYFRA 21–1 and tumor extension, with significantly higher values in patients with metastases than in those without metastases (p < 0.0001). Abnormal CEA values were found in 49.1%, CA 125 in 39%, SCC in 27.8% and NSE in 21.3% of the patients with active cancer. With respect to histological type, CYFRA was elevated in 68.3% of squamous cell carcinomas (CEA: 46.7%, SCC: 50%, CA 125:31.7%, NSE: 11.7%), in 54.8% of adenocarcinomas (CEA: 62%, SCC: 26.2%, CA 125: 59.5%, NSE: 9.5%), in 78.6% of LCLC (CEA: 64.3%, SCC: 28.6%, CA 125: 78.6%, NSE: 7.1%) and in 30% of SCLC (CEA: 37.7%, SCC: 3.8%, CA 125:20.8%, NSE: 45.3%). In summary, CYFRA 21–1 is the most sensitive tumor marker in patients with lung cancer, especially in NSCLC patients.

Evaluation of Cytokeratin 19 Serum Fragments (Cyfra 21–1) in Patients with Lung Cancer: Results of a Multicenter Trial

Recently, a new immunometric assay (Cyfra 21–1) was developed to measure serum concentrations of a soluble fragment of cytokeratin subunit 19. With this method, supplied by Boehringer Mannheim (EIA Test Cyfra 21–1), an Italian multicenter trial was performed in patients with lung cancer. Cyfra 21–1 serum levels were determined in 568 normal subjects (blood donors), 607 patients with non-malignant diseases (491 respiratory diseases) and 730 patients with malignancies. In the latter group 584 had lung cancer. All these 584 patients had pathologically confirmed disease; 314 were epidermoid tumors, 166 adenocarcinomas, 88 small cell cancers and 16 large cell cancers.

In the 568 healthy blood donors the mean Cyfra 21–1 value was 0.91 ng/ml (SD 0.47 ng/ml; range 0.05–2.90 ng/ml). A threshold of 1.9 ng/ml was chosen as the upper limit of normality. High levels of Cyfra21–1 were observed in patients with chronic hepatitis (positivity rate: 17/51–33.3%) and with pancreatitis (positivity rate 5/16 - 31.3%). In 114 out of 491 (23.2%) patients with respiratory diseases Cyfra 21–1 showed values greater than 1.9 ng/ml. The overall sensitivity (all stages) of Cyfra 21–1 in lung cancer was 65.6% (383/584). When the histology was considered the highest positivity rates were found in patients with squamous cell tumors (226/314; 72%) followed by adenocarcinomas (105/166; 63%). In patients with SCLC the global sensitivity was 52.3% (46/88). Higher sensitivity of Cyfra 21–1 was observed from stage I to stage IV (53.9% vs 85.7%; Chisquare: p < 0.01). When comparing patients in whom curative resections were possible (up to stage IIIa) with patients suffering from inoperable tumors, a significant difference in Cyfra 21–1 positivies was found (59% vs 81.5%; Chi square p < 0.01).

Clinical utility of cytokeratins as tumor markers

Cytokeratins, belonging to the intermediate filament (IF) protein family, are particularly useful tools in oncology diagnostics. At present, more than 20 different cytokeratins have been identified, of which cytokeratins 8, 18, and 19 are the most abundant in simple epithelial cells. Upon release from proliferating or apoptotic cells, cytokeratins provide useful markers for epithelial malignancies, distinctly reflecting ongoing cell activity. It appears that motifs in certain cytokeratins make them likely substrates for caspase degradation, and their subsequent release occurs during the intermediate events in apoptosis. The clinical value of determining soluble cytokeratin protein fragments in body fluids lies in the early detection of recurrence and the fast assessment of the efficacy of therapy response in epithelial cell carcinomas. The three most applied cytokeratin markers used in the clinic are tissue polypeptide antigen (TPA), tissue polypeptide specific antigen (TPS), and CYFRA 21-1. TPA is a broad spectrum test that measures cytokeratins 8, 18, and 19. TPS and CYFRA 21-1 assays are more specific and measure cytokeratin 18 and cytokeratin 19, respectively. By following patients with repeated testing during management, the oncologist may obtain critical information regarding the growth activity in symptomatic patients. Although their main use is to monitor treatment and evaluate response to therapy, early prognostic information particularly on tumor progression and metastasis formation is also provided for several types of cancers. Cytokeratin tumor markers can accurately predict disease status before conventional methods and offer a simple, noninvasive, cheap, and reliable tool for more efficient management.

ProGRP: a new biomarker for small cell lung cancer

Progastrin-releasing peptide (ProGRP) is a recently identified biomarker of small cell lung cancer (SCLC), a disorder of neuroendocrine tissue differentiation. The upper normal limit of ProGRP in the circulation is 50 pg/ml. Impaired glomerular filtration tends to increase circulating levels and confound the tumor marker significance of modestly elevated values. Excluding patients with renal failure, circulating levels did not exceed 80 pg/ml in benign disease (3% of cases in excess of the upper normal limit) or 120 pg/ml in malignancy other than lung cancer and neuroendocrine tumors (5% of cases in excess of the upper limit). ProGRP serum levels are clearly related to the lung cancer histological type with significantly higher levels observed in SCLC than in nonsmall cell lung cancer (NSCLC). Circulating ProGRP in excess of 120 mg/ml was found in only 4% of cases of NSCLC with another 22% presenting with modestly elevated levels in excess of the upper normal limit. By contrast, abnormal ProGRP results are found in 60-70% and in 75-90% of SCLC patients with local and extensive disease, respectively. ProGRP is a more sensitive biomarker than is neuron-specific enolase (NSE) for SCLC, but thus far has not been found in multivariate analysis to have independent prognostic significance. Preliminary studies suggest ProGRP will have utility in conjunction with NSE in monitoring the therapy of established SCLC.

Neuron-specific enolase is an effective tumour marker in non-small cell lung cancer (NSCLC)

BACKGROUND

Neuron-specific enolase (NSE) is a well known marker of small cell lung cancer. The present study was designed to assess the clinical value of NSE in non-small cell lung cancer (NSCLC), as compared to that of carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA).

METHODS

The study comprised 448 new consecutive NSCLC patients seen from 1996 to 2001. A set of 30 anthropometric, clinical, physical, laboratory, radiological, and pathological variables was prospectively recorded for all patients. Patients were carefully followed-up, and their subsequent clinical course recorded.

RESULTS

Increased values of NSE were present in 32% of the patients. Bivariate analyses showed that NSE, TPA and CEA were significantly correlated with each other, lactate dehydrogenase, tumour diameter, and disease extent. Univariate analyses showed that patients with elevated concentration of both NSE and TPA had significantly shorter survivals than patients with low values (30 [95% CI: 25-35] vs. 61 weeks [46-76], and 30 [CI: 24-36] vs. 59 weeks [40-79], respectively, P=0.0000). The Cox proportional hazards model including all the 22 variables significant in univariate analysis selected, in decreasing order of significance, the following variables: (1) N factor; (2) main treatment; (3) ECOG PS; (4) CNS metastasis; (5) age; (6) tumour cavitation; (7) NSE; (8) T factor; and (9) adrenal gland metastasis.

CONCLUSIONS

This data indicates that serum assay of NSE is a useful marker also in NSCLC and a significant predictor of survival, independently of the other prognostic factors.

Serum biomarkers facilitate the recognition of early- stage cancer and may guide the selection of surgical candidates: a study of carcinoembryonic antigen and tissue polypeptide antigen in patients with operable non-small cell lung cancer

OBJECTIVES

Copious literature shows that in lung cancer many serum markers, especially the cytokeratin degradation products, correlate with the extent of disease. In 1995, we suggested the possibility of predicting the resectability of non-small cell lung cancer by measuring the plasma level of the tissue polypeptide antigen, a marker of the cytokeratin family. This study was designed (1) to confirm the earlier data in a new prospective evaluation, (2) to comparatively assess another classic biomarker (ie, the carcinoembryonic antigen), and (3) to incorporate their results into the preoperative evaluation of non-small cell lung cancer.

METHODS

We analyzed the database of a single institution over a 5-year period (1994-1998) in a community-based hospital and second referral level institution for a province of 500,000 people. The database included 124 consecutive patients (105 men) with pathologically documented lung cancer (50% with adenocarcinoma) accurately staged, clinically judged operable or potentially operable, and eventually operated on. Anthropometric, clinical, and laboratory data (including the carcinoembryonic antigen and tissue polypeptide antigen serum levels) and the results of a complex staging workup were prospectively recorded. Receiver-operating characteristic curves and diagnostic formulas were used for data analysis.

RESULTS

Computed tomography of the thorax, upper part of the abdomen, and brain was the most accurate preoperative method to assess tumor resectability (receiver-operating characteristic area: 0.76, 95% confidence intervals: 0.67-0.86, P =.000; accuracy rate: 77%, confidence intervals: 69%-84%). Tissue polypeptide antigen was also predictive for tumor resectability (receiver-operating characteristic area: 0.62, 95% confidence intervals: 0.51-0.73, P =.035; accuracy rate at a threshold level of 110 U/L: 65%, 95% confidence intervals: 56%-73%). Carcinoembryonic antigen was diagnostic only at the extreme values of its distribution (accuracy rate at a level up to 10 ng/mL: 69%, 95% confidence intervals: 60%-77%). The probability of finding resectable disease at the time of the operation increased from 78% (baseline computed tomography-based probability) to 83% when the concentration of tissue polypeptide antigen was lower than 90 U/L and to 85% when the concentration of carcinoembryonic antigen was below 10 ng/mL. The probability of discovering an advanced disease increased from 68% (baseline computed tomography-based probability) to 89% when tissue polypeptide antigen levels were abnormal and to 100% when carcinoembryonic antigen concentrations were higher than 10 ng/mL. Conversely, the predictability of computed tomography was diminished by contrasting biomarker results, requiring further clinical investigations.

CONCLUSIONS

Computed tomography remains the gold standard for the preoperative evaluation of non-small cell lung cancer, although it may significantly underestimate the real tumor extension. The addition of the easy and inexpensive tissue polypeptide antigen test (with or without carcinoembryonic antigen) is capable of correcting this underestimation and helps to decide whether to completely rely on computed tomography or order additional clinical investigations.

Cytokeratin-derived markers of lung cancer

Various evaluation methods are available for aiding clinicians in lung cancer management. Some of these methods are highly specific. However, they are also invasive and burdened by non-negligible complication rates (e.g., mediastinoscopy); other methods are highly accurate and noninvasive, but require expensive equipment and well-trained personnel (e.g., PET scanning); others are fast, inexpensive and safe. However, their diagnostic yield is low and requires further clinical testing (an example of such tests is the chest-x-ray film). There is probably only one way to perform an easy, inexpensive, repeatable test, which is also fairly accurate and predictive. This is tumor marker testing, which--as a large and specialized literature shows--can be highly effective when based on a cytokeratin-derived marker assay.

CEA, CYFRA21-1 and SCC in non-small cell lung cancer

CEA, SCC and CYFRA 21-1 were measured in samples of serum coming from 105 'Non small cell lung cancer' (NSCLC) patients. The present study has been carried out to compare these markers, to analyse their prognostic significance and to determine the best combination of tumor markers. The median value and interquartile range were: CYFRA 21-1: 2,3 ng/ml, CEA: 3,7 ng/ml, SCC: 1,2 ng/ml. CEA demonstrated higher values in adenocarcinomas (P = 0.04). SCC and CYFRA 21-1 were comparable in the different histologic groups. CYFRA 21-1 and CEA values were dependant on tumor stage. Advanced tumors (T3 and T4) demonstrated higher serum CYFRA 21-1 level (P = 0.0006). CYFRA 21-1 was higher than 3,3 ng/ml in 36% of patients. CEA was higher than 5 ng/ml in 38% of patients and SCC was higher than 2 ng/ml in 27% of patients. Patients with a high CEA and CYFRA21-1 serum level had a shorter survival than those with a normal serum level. In a Cox regression analysis four variables (TNM stage, age, CYFRA 21-1 and CEA level) were found to be significant in the prediction of survival; CYFRA 21-1 level had the lowest P value (P = 0.0002). The current study suggests the use of a combination of CEA and CYFRA 21-1 in the clinical care of NSCLC.

Monitoring lung cancer with tissue polypeptide antigen: an ancillary, profitable serum test to evaluate treatment response and posttreatment disease status

The tissue polypeptide antigen (TPA) is a protein produced and released by proliferating cells that possesses several characteristics for an ideal tumor marker. Our purpose was to define the clinical yield of TPA in the follow-up of patients with lung cancer (LC). Three hundred and forty-one new LC patients underwent an extensive pre-treatment staging evaluation (UICC 1987 classification) and a TPA serum measurement. We restaged them at regular times by: 1, clinical history and physical examination, routine lab tests, chest X-rays, and any other examination as suggested by the prior baseline evaluation, and 2, the serum level of TPA. We evaluated a total of 1513 assays (including 1172 posttreatment measurements). Individual values of TPA correlated significantly with treatment response and disease status. Patients with small-cell lung cancer showed the lowest correlation indexes between clinical parameters and the marker. Each objective response to treatment or disease progression was almost always associated to consistent changes of TPA (P < 0.0001, by the Wilcoxon's test). A 50% reduction under the prior TPA value was 30% sensitive, 90% specific, and 88% accurate in the diagnosis of response to treatment. The same percent reduction was 18% sensitive, 92% specific, and 88% accurate in predicting a future response. A 100% increase over the prior level of TPA permitted to recognize tumor relapses with sensitivity, specificity, and accuracy of 30%, 93%, and 80% (diagnosis of progression), and 18%, 92%, and 78% (prediction of progression). Similar diagnostic yields were observed using progressively increasing or progressively decreasing changes of the marker level. In lung cancer, the diagnosis (and even the anticipation) of disease status is often possible using appropriate threshold value of TPA.

The clinical value of neuron-specific enolase as a tumor marker in bronchoalveolar lavage

BACKGROUND

Neuron-specific enolase (NSE) is used in the staging and monitoring of responses to therapy and the detection of recurrences in lung cancer. The diagnostic value of NSE has been under discussion. This may be because NSE usually has been studied in the sera of patients with bronchogenic carcinoma and not in the bronchoalveolar lavage (BAL).

METHODS

The NSE levels in the BAL of three groups--control subjects, patients with chronic bronchitis, and patients with tumors--were analyzed. The fluid obtained was centrifuged. The NSE was analyzed in the supernatant of the BAL (NSE, Pharmacia, Columbia, MD). Its concentrations were calculated in relation to milligrams of total protein.

RESULTS

A significant difference was noted in the level of NSE in the BAL of the tumor group compared with those of the other two groups. No differences were observed between the other two groups or between healthy smokers and nonsmokers. No correlation was found with the histologic type of pulmonary carcinoma and NSE levels in BAL. The NSE levels were higher in the lavages of patients with primary pulmonary carcinomas than in those with metastases.

CONCLUSIONS

Neuron-specific enolase could be of aid in the early diagnosis of solitary pulmonary nodules and lung cancer. More studies would be required to identify a correlation between NSE levels in BAL and those in serum, or between NSE levels in BAL and tumor size and location and disease stage of lung cancer.

Serological tumor markers for small cell lung cancer and their therapeutic implications

Serological tumor markers may become widely used as inexpensive and non-invasive methods of cancer detection. Markers of current interest for small cell lung cancer (SCLC) comprise enzymes, peptides, proteins, and carbohydrates. None of the serological markers for SCLC have yet proven to be of diagnostic value and at present their use is limited to monitoring disease and indicating prognosis. However, whilst serological markers related to the metabolic state of SCLC cells, such as neuron-specific enolase, serum thymidine kinase and tissue polypeptide antigen, may only be used for monitoring patients and for estimating prognosis, the other serological markers under current investigation may be used to indicate new treatment forms. Several novel approaches, including interference in the autocrine growth-regulating loop of SCLC by either peptides or antibodies, have been tried, SCLC is a highly heterogeneous tumor with respect to antigen expression, regulation of growth, and differentiation state. It is therefore important that new interventions are directed against both antigen-positive and antigen-negative tumor cells. For instance, radioisotopes or enzymes coupled to antibodies may be effective by exerting toxicity at some distance from the target. Antigens expressed on SCLC cells, such as peptide receptors involved in growth regulation, carbohydrate antigens like Lewis antigens, carcinoembryonic antigen and the ganglioside fucosylGM1, provide potential targets for antibody-conjugated therapy.

Quantitative analysis of carcinoembryonic antigen, squamous cell carcinoma antigen, CA 125, and CA 50 cytosolic content in non-small cell lung cancer

BACKGROUND

The cytosolic content of carcinoembryonic antigen (CEA), squamous cell carcinoma (SCC), CA 125, and CA 50 antigens in non-small cell lung cancer (NSCLC) is analyzed in this study. The aim was to ascertain the relationship between tumor marker content and the clinicopathologic aspects of this neoplasm.

METHODS

Lung tissue samples were obtained at the time of surgery from 75 patients with NSCLC patients (samples of tumor and unaffected tissue) and 29 subjects with idiopathic pneumothorax. All determinations were performed on cytosols obtained from lung specimens. CEA and CA 125 were determined by enzyme immunoassay, SCC antigen by radioimmunoassay, and CA 50 by fluoroimmunoassay. Tumor marker content was analyzed by TNM stage, histologic type, tumor grade, and number of atypias.

RESULTS

The concentration of the four markers was significantly higher in cytosol obtained from neoplastic tissue. Frequency of elevated levels of CEA was higher in adenocarcinoma (87% cases expressing high levels of the marker), SCC antigen in epidermoid carcinoma (65% expressing high levels), and CA 125 in large cell carcinomas (100% expressing high levels). No association was found between TNM stage and cytosol concentration for any of the four markers. CEA exhibited significantly greater concentration in well differentiated tumors, whereas this was true of CA 125 in poorly differentiated tumors. CA 125 content was higher in tumors with more atypia.

CONCLUSIONS

Cytosolic quantification of tumor markers may be an adjuvant mechanism to evaluate histologic subtypes of non-small cell lung cancer and identification of tumors with poorly differentiated features.

Squamous cell carcinoma antigen (SCC Ag) in the diagnosis and prognosis of lung cancer

OBJECTIVE

We have studied the usefulness of squamous cell carcinoma antigen (SCC Ag) in diagnosis and prognosis of lung cancer (LC).

MATERIAL AND METHODS

We have measured the serum SCC Ag levels in 388 subjects: 69 healthy persons; 103 with nonmalignant lung diseases (NMLD); 24 with lung metastasis of extrapulmonary origin (LMEO); and 192 with LC (88, with squamous cell carcinoma [SCC] type). In 55 with SCC, we analyzed the survival time.

RESULTS

Serum SCC Ag was above 2.5 ng/ml in 1.4 percent of healthy persons; 2.9 percent of those with NMLD; 8.3 percent of those with LMEO; and 27.6 percent of those with LC. Such percentage was 47.7 percent in SCC. In this type, there were significant differences according to the extent of disease (61.6 percent in advanced stages, and 26.5 percent in localized stages, p = 0.002). In the other types, the sensitivity was substantially lower. The initial SCC Ag has prognostic significance (p = 0.02) in the univariate analysis, but it loses such significance in a multivariate model, including the stage.

CONCLUSIONS

Therefore, we do not recommend this marker in the clinical management of patients with LC, even it can be useful in the differential diagnosis if used in combination with other markers.

Prognostic significance of serum CA 125 antigen assay in patients with non-small cell lung cancer

BACKGROUND

The serum levels of CA 125 tumor-associated antigen in patients with lung cancer have been previously related to TNM stage, histologic type, and survival rate. In the current study, the prognostic information provided by the CA 125 antigen assay was analyzed.

METHODS

Preoperative serum of CA 125 antigen was determined in 137 patients with non-small cell lung cancer. The assay was performed by means of a solid-phase enzyme-immunoassay test. The influence of CA 125 serum level on postoperative outcome was studied by a multivariate analysis, performed with Cox's proportional hazards regression model.

RESULTS

Patients whose initial CA 125 level was higher than 15 U/ml had a 3.25-fold greater likelihood of relapse (95% confidence interval [CI], 1.7-6.21) (P < 0.001) and a 4.27-fold greater likelihood of deaths (95% CI, 2.42-7.55) (P < 0.001) due to cancer than patients with lower values. For patients with serum levels over 15 U/ml, the 36-month survival rate posttreatment was lower (67% versus 20%) (P < 0.001), as was the disease-free rate (64% versus 13%) (P < 0.001). After adjustment for TNM stages, histologic type, sex, and age, patients with CA 125 values over 15 U/ml continued exhibiting higher risk of relapse (hazard ratio, 2.2; 95% CI, 1.04-4.69) (P = 0.04) and higher risk of death (hazard ratio, 2.42; 95% CI, 1.29-4.54) (P = 0.006).

CONCLUSIONS

CA 125 is an independent prognostic factor of survival and tumor relapse in non-small cell lung cancer. The preoperative serum level of CA 125 antigen is inversely correlated with the outcome figures. The authors suggest that CA 125 be included in any future multifactorial analysis of survival.

Serum tumor markers in non-small cell lung cancer. A comparative analysis

BACKGROUND

The role of serum tumor markers in non-small cell lung cancer (NSCLC) remains undefined. New proposed markers have seldom been rigorously compared with existing standards. The authors prospectively compared the performance of three new monoclonal antibodies (MoAb) (5E8, 5C7, and 1F10) with the established serum markers carcinoembryonic antigen (CEA) and squamous cell carcinoma antigen (SCC).

METHODS

The cohort consisted of 45 consecutive out-patients with newly diagnosed NSCLC: Control subjects were 38 outpatients with non-neoplastic chronic pulmonary diseases. Blood from each patient and control subject was assayed for all five tumor markers. An enzyme-linked immunosorbent assay (ELISA) was used to determine 5E8, 5C7, and 1F10 reactivity. Commercially available kits were used to measure SCC by radioimmunoassay and CEA by ELISA: Individual and combinations of tumor markers were compared in terms of sensitivity, specificity, and accuracy for NSCLC diagnosis.

RESULTS

5E8 plus 5C7 plus 1F10 significantly surpassed SCC plus CEA in terms of sensitivity (P < 0.05) and proved the most accurate marker combination. Among single markers, 5E8 was most specific, 5C7 most sensitive, and 5C7 and 1F10 each most accurate, but differences from CEA alone were not significant. Subgroup analysis by histologic type and stage demonstrated similar findings, and marker combinations yielded little additional diagnostic benefit.

CONCLUSIONS

5E8, 5C7, and 1F10 performed marginally better than did CEA and SCC in patients with newly diagnosed NSCLC: Many limitations apply in defining a clinical niche for these tumor markers in NSCLC, although 5E8, 5C7, and 1F10 previously have demonstrated a modest prognostic value. An adjunctive role in a few specific clinical contexts remains possible.

Clinical usefulness of serum assays of neuron-specific enolase, carcinoembryonic antigen and CA-50 antigen in the diagnosis of lung cancer

Serum concentrations of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA) and CA-50 antigen were determined in 168 consecutive patients with lung cancer. All three markers were significantly elevated compared with levels in 102 patients with non-malignant chest diseases. NSE and CEA varied significantly across histological lung cancer types, with most highly elevated serum levels in small cell lung cancer and adenocarcinomas, respectively. The overall diagnostic accuracy was 0.66 for NSE, 0.74 for CEA, and 0.62 for CA-50, implying that CEA best discriminated between lung cancer and benign chest diseases, while CA-50 was less efficient as a diagnostic marker. In multivariate analysis of the three markers combined, a positive predictive value of 95% for lung cancer could be achieved with a diagnostic sensitivity of 57%, with a cut-off level defined as 0.037.NSE + 0.052.CEA + 0.011.CA-50 > 1. In 22% of the cancer patients, the time from admission to histological or cytological lung cancer diagnosis exceeded 1 month. In 52% of these patients, the initial weighted tumour marker index was > 1, strongly implying the cancer diagnosis. The study lends support to the potential use of combined analysis of NSE, CEA and CA-50 as a complementary tool in the diagnosis of lung cancer.

Prognostic value of the tissue polypeptide antigen in lung cancer

The prognostic impact of TPA was evaluated by assaying the marker in the serum of 563 patients with a newly diagnosed bronchogenic carcinoma. The group included patients with squamous cell cancers and others with tumors of diverse or undefined histologies. Raised levels of TPA were clearly associated with a shortened survival, even adjusting for the stage of disease. A Cox's proportional hazards regression analysis, incorporating all major prognostic factors, selected TPA as an independent survival predictor. In the regression model, however, TPA was less important than disease extent, KPS and weight loss. Another multivariate analysis was made in a subgroup of 121 patients who, because of poor KPS or advanced age, had undergone a limited staging workup; TPA came out as the first most important factor. This study shows that TPA is an important prognostic factor and that it should be included among laboratory data evaluated in lung cancer studies.

Preliminary Study on Auxiliary Value of Serum Basic Fetoprotein in Diagnosing Lung Cancer

To characterize basic fetoprotein (BFP) as a new tumor marker, we measured serum levels of BFP and 5 other tumor markers (CA19-9, CEA, NSE, SCC, and TPA) concomitantly in 65 patients with lung cancer, 57 patients with benign pulmonary disease, and 40 healthy volunteers. The sensitivity of BFP was 43%, the specificity 82% and the accuracy 61%. The positivity increased in relation to stage of the disease. There was no correlation between positivity of BFP and histologic type. On the whole, BFP appeared to be analogous to TPA in terms of broad spectrum and to have an auxiliary value in diagnosing lung cancer.