Increased carcinoembryonic antigen concentrations in sera and bronchoalveolar lavage fluids of patients with pulmonary alveolar proteinosis

Differential expression profiling of transcripts of IDH1, CEA, Cyfra21-1, and TPA in stage IIIa non-small cell lung cancer (NSCLC) of smokers and non-smokers cases with air quality index

Smoking tobacco is the major hazard for lung cancer in Indian subcontinent especially men, compare to woman where, other important risk factors such as air pollutions are responsible. So, the aim of the study is to compare chronic smokers (CS) and non-smokers living in areas with air quality categorized as poor (AQI 201-300) or moderate (AQI 101-200). We measured the expression of non-small cell lung cancer (NSCLC) biomarkers;. IDH1, CEA, Cyfra21-1, and TPA through quantitative Real-Time PCR (qRT-PCR) and compared the levels of upregulation of the transcripts in stage IIIa NSCLC over control benign tissues among the smoking and AQI settings. Though the all biomarkers were significantly up-regulated in tumor tissues compared to control benign tissues, the fold change increase of IDH1 and CEA was highest in CS-poor/moderate AQI, followed by non-smokers-poor AQI and non-smokers moderate AQI. This indicates the aggressiveness and poor prognosis in CS living in either poor or moderate AQI areas. The level of Cyfra21-1 was lower in in the CS groups in comparison to non-smokers in the poor AQI area. This suggest higher Lung Squamous cell carcinoma histology in non-smokers living areas with poor AQI. Hence, we conclude that poor air quality can be as injurious for lung cancers as chronic smoking.

Pulmonary alveolar proteinosis

Pulmonary alveolar proteinosis (PAP) is a syndrome characterized by the accumulation of alveolar surfactant and dysfunction of alveolar macrophages. PAP results in progressive dyspnoea of insidious onset, hypoxaemic respiratory failure, secondary infections and pulmonary fibrosis. PAP can be classified into different types on the basis of the pathogenetic mechanism: primary PAP is characterized by the disruption of granulocyte-macrophage colony-stimulating factor (GM-CSF) signalling and can be autoimmune (caused by elevated levels of GM-CSF autoantibodies) or hereditary (due to mutations in CSF2RA or CSF2RB, encoding GM-CSF receptor subunits); secondary PAP results from various underlying conditions; and congenital PAP is caused by mutations in genes involved in surfactant production. In most patients, pathogenesis is driven by reduced GM-CSF-dependent cholesterol clearance in alveolar macrophages, which impairs alveolar surfactant clearance. PAP has a prevalence of at least 7 cases per million individuals in large population studies and affects men, women and children of all ages, ethnicities and geographical locations irrespective of socioeconomic status, although it is more-prevalent in smokers. Autoimmune PAP accounts for >90% of all cases. Management aims at improving symptoms and quality of life; whole-lung lavage effectively removes excessive surfactant. Novel pathogenesis-based therapies are in development, targeting GM-CSF signalling, immune modulation and cholesterol homeostasis.

Clinical significance of cigarette smoking and dust exposure in pulmonary alveolar proteinosis: a Korean national survey

BACKGROUND

This study aimed to investigate clinical characteristics of Korean PAP patients and to examine the potential risk factors of PAP.

METHODS

We retrospectively reviewed medical records of 78 Korean PAP patients diagnosed between 1993 and 2014. Patients were classified into two groups according to the presence/absence of treatment (lavage). Clinical and laboratory features were compared between the two groups.

RESULTS

Of the total 78 PAP patients, 60% were male and median age at diagnosis was 47.5 years. Fifty three percent were ever smokers (median 22 pack-years) and 48% had a history of dust exposure (metal 26.5%, stone or sand 20.6%, chemical or paint 17.7%, farming dust 14.7%, diesel 14.7%, textile 2.9%, and wood 2.9%). A history of cigarette smoking or dust exposure was present in 70.5% of the total PAP patients, with 23% having both of them. Patients who underwent lavage (n = 38) presented symptoms more frequently (38/38 [100%] vs. 24/40 [60%], P < 0.001) and had significantly lower PaO₂ and DL_CO with higher D(A-a)O₂ at the onset of disease than those without lavage (n = 40) (P = 0.006, P < 0.001, and P = 0.036, respectively). Correspondingly, the distribution of disease severity score (DSS) differed significantly between the two groups (P = 0.001). Based on these, when the total patients were categorized according to DSS (low DSS [DSS 1-2] vs. high DSS [DSS 3-5]), smoking status differed significantly between the two groups with the proportion of current smokers significantly higher in the high DSS group (11/22 [50%] vs. 7/39 [17.9%], P = 0.008). Furthermore, current smokers had meaningfully higher DSS and serum CEA levels than non-current smokers (P = 0.011 and P = 0.031), whereas no difference was found between smokers and non-smokers. Regarding type of exposed dust, farming dust was significantly associated with more severe form of PAP (P = 0.004).

CONCLUSION

A considerable proportion of PAP patients had a history of cigarette smoking and/or dust exposure, suggestive of their possible roles in the development of PAP. Active cigarette smoking at the onset of PAP is associated with the severity of PAP.

Elevated serum CEA levels are associated with the explosive progression of lung adenocarcinoma harboring EGFR mutations

BACKGROUND

Serum carcinoembryonic antigen (CEA) levels are a predictor of epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) efficacy and are associated with epidermal growth factor receptor (EGFR) gene mutations. However, the clinical significance of plasma CEA level changes during different cycles of target therapy is unknown for lung adenocarcinoma patients with sensitizing EGFR mutations.

METHODS

In total, 155 patients with lung adenocarcinoma were enrolled in this retrospective study between 2011 and 2015. EGFR mutations were detected by RT-PCR (real-time quantitative PCR). Plasma CEA levels were measured prior to different EGFR-TKI treatment cycles. Computed tomography (CT) scans were conducted every 2 months to assess the therapeutic efficacy.

RESULTS

Serum CEA concentrations were significantly associated with EGFR mutations (p < 0.05). Furthermore, in all patients treated with EGFR-TKIs, the serum CEA levels increased with disease progression (p < 0.005). A COX multivariate analysis revealed that CEA levels 16.2 times above normal were associated with early disease progression (HR, 5.77; 95% CI:2.36 ~ 14.11; p < 0.001). Based on this finding, a threshold was set at the median time of 8.3 months. Patients with EGFR mutations exhibited a median progression-free survival time of 12.8 months. Serum CEA levels were markedly increased compared to levels measured 4.5 months prior to the changes detected via CT scans for patients resistant to EGFR-TKIs.

CONCLUSIONS

Elevated CEA levels during targeted therapy may be a more sensitive predictor of explosive lung adenocarcinoma progression in patients harboring mutant EGFRs compared to traditional imaging methods.

The Clinical Clues of Pulmonary Alveolar Proteinosis: A Report of 11 Cases and Literature Review

Pulmonary alveolar proteinosis (PAP) is a rare interstitial lung disease characterized by the abnormal alveolar accumulation of surfactant components. The diagnosis of PAP can be easily missed since it is rare and lacks specific clinical symptoms. It is of great importance to have a better understanding of the crucial clue to clinically diagnose PAP and take PAP into consideration in the differential diagnosis of interstitial pulmonary diseases or other diseases with similar manifestations. Here, we analyze the clinical characteristics of 11 cases of PAP patients in local hospital and review the relevant literature in order to provide more information in diagnosis and management of PAP. In our observation, cyfra21-1 and neuron-specific enolase (NSE) known as tumor markers probably can be useful serum markers for diagnosis of PAP. As for the method of pathologic diagnosis, open-lung biopsy was the gold standard but now it is less required because findings on examination of bronchoalveolar lavage fluid (BALF) can help to make the diagnosis. We also have deep experience about when and how to carry out lung lavage.

MUC1 gene polymorphisms are associated with serum KL-6 levels and pulmonary dysfunction in pulmonary alveolar proteinosis

BACKGROUND

KL-6, a human MUC1 mucin, is a sensitive biomarker for interstitial lung diseases including pulmonary alveolar proteinosis (PAP). A correlation between MUC1 gene single nucleotide polymorphism (SNP) rs4072037 genotype and serum KL-6 levels has been reported. This study was aimed at investigating the correlation between MUC1 SNP genotype, severity of disease and disease outcome in PAP.

METHODS

Twenty four patients with PAP and 30 healthy volunteers were studied. MUC1 rs4072037 was detected by using a real-time polymerase chain reaction (RT-PCR). Genotyping was performed by pyrosequencing. KL-6 levels were measured in serum by Nanopia KL-6 assay (SEKISUI Diagnostics).

RESULTS

The frequency of MUC1 rs4072037 alleles was significantly different between PAP patients and healthy volunteers (PAP, A/A 46%, A/G 54%, G/G 0%; healthy controls, A/A 30%, A/G 40%, G/G 30%; p = 0.013). Serum KL-6 levels were significantly higher in PAP patients than in controls (p < 0.0001), and significantly higher in PAP patients with A/A genotype than in those with A/G genotype (p = 0.007). Patients with A/A genotype had higher alveolar-arterial oxygen difference (A-aDO2) and lower DLco compared to those with A/G genotype (p = 0.027 and p = 0.012, respectively). Multivariate analysis, Kaplan-Meier analysis and C statistics showed that the rs4072037 A/A genotype was associated with higher rate of disease progression (HR: 5.557, p = 0.014).

CONCLUSIONS

MUC1 rs4072037 A/A genotype is associated with more severe pulmonary dysfunction and a higher rate of disease progression in PAP patients.

Serum KL-6 is a predictor of outcome in pulmonary alveolar proteinosis

Background

Pulmonary alveolar proteinosis (PAP) is a rare disorder characterised by abundant alveolar accumulation of surfactant lipoproteins. Serum levels of KL-6, high molecular weight human MUC1 mucin, are increased in the majority of patients with PAP. The prognostic significance of KL-6 in PAP is still unknown. Aim of the study was to evaluate whether serum KL-6 levels correlate with the outcome of the disease.

Patients and methods

From 2006 to 2012, we prospectively studied 33 patients with primary autoimmune PAP. We measured serum KL-6 levels by ELISA (Eisai, Tokyo, Japan), and evaluated the correlation between initial KL-6 levels and clinical variables. Disease progression was defined as deterioration of symptoms, and/or lung function, and/or chest imaging.

Main results

The initial serum KL-6 levels were significantly correlated with the baseline PaO₂, A-aDO₂, DLCO, VC and TLC (p=0.042, 0.012, 0.012, 0.02 and 0.013, respectively). The change over time of serum KL-6 correlated with the change over time of DLCO (p=0.017). The initial serum KL-6 levels were significantly higher in patients with disease progression than in those with remission (p<0.001). At a cut-off level of 1526 U/mL, the initial serum KL-6 level predicted disease progression (Se 81%, Sp 94%). At a cut-off level of 2157 U/mL, the initial serum KL-6 predicted the necessity of repeated whole lung lavage (Se 83%, Sp 96%). In the multivariate analysis, the initial serum level of KL-6 was the strongest predictor of disease progression (HR 9.41, p=0.008).

Conclusions

Serum KL-6 seems to predict outcome in PAP.

Assessment and management of pulmonary alveolar proteinosis in a reference center

Pulmonary alveolar proteinosis (PAP) is a term defining an ultra-rare group of disorders characterised by a perturbation in surfactant homeostasis, resulting in its accumulation within airspaces and impaired gas transfer. In this report we provide data from a cohort of PAP patients (n=81) followed for more than two decades at the San Matteo University Hospital of Pavia, Italy. In agreement with other large series in PAP individuals, 90% of the study subjects were affected by autoimmune/idiopathic PAP, while the remaining subjects were divided as follow: congenital 1%, secondary 4% and PAP-like 5%. The disease affected males and females with a ratio of 2:1 and approximately one third of PAP patients were lifelong nonsmokers. Occupational exposure was reported in 35% of subjects in this series. With reference to the PAP clinical course, in 29 patients (7% with spontaneous remission) disease severity did not necessitate whole lung lavage (WLL) in the long-term follow up. On the other hand, 44 PAP patients underwent therapeutic WLL: in 31 subjects a single WLL was sufficient to provide long term, durable benefit, whereas 13 patients required multiple WLLs. The intra-patient mean interval between two consecutive WLLs was 15.7±13.6 months. When baseline data among never lavaged and PAP patients lavaged at least once were compared, the need for lavage was significantly associated with serum biomarkers (CEA, Cyfra, LDH), lung function parameters forced vital capacity (FVC), and lung diffusing capacity (Dlco). We conclude that patient cohorts with an ultra-rare disease, such as PAP, referred to a single reference center, can provide useful information on the natural history and clinical course of the disease.

Prognostic and predictive value of carcinoembryonic antigen and cytokeratin-19 fragments levels in advanced non-small cell lung cancer patients treated with gefitinib or erlotinib

PURPOSE

The prognostic and predictive value of pretreatment serum levels of carcinoembryonic antigen (CEA) and cytokeratin-19 fragments (CYFRA 21-1) were assessed in advanced non-small cell lung cancer (NSCLC) patients treated with gefitinib or erlotinib.

MATERIALS AND METHODS

Pretreatment CEA and CYFRA 21-1 were measured in 123 advanced NSCLC patients receiving gefitinib or erlotinib. High CEA levels (h-CEA) were significantly associated with females, patients with adenocarcinoma, and non-smokers.

RESULTS

Low CYFRA 21-1 levels (l-CYFRA) were significantly associated with a good performance status (ECOG PS 0-1). The overall response rate (RR) was 27.6%, and higher RR was associated with adenocarcinoma, h-CEA, and epidermal growth factor receptor (EGFR) mutation. Patients with h-CEA had significantly longer progression-free survival (PFS) (p=0.021). Patients with l-CYFRA had significantly longer PFS and overall survival (p=0.006 and p<0.001, respectively). Of note, h-CEA and l-CYFRA had good prognosis in patients with unknown EGFR mutation status or patients with squamous cell carcinoma (p=0.021 and p=0.015, respectively). A good ECOG PS (HR=0.45, p=0.017), h-CEA (HR=0.41, p=0.007), l-CYFRA 21-1 (HR=0.52, p=0.025), and an EGFR mutation (HR=0.22, p<0.001) were independently predictive of a longer PFS.

CONCLUSION

h-CEA and l-CYFRA 21-1 may be prognostic and predictive serum markers for higher response and longer survival in patients with advanced NSCLC receiving gefitinib or erlotinib, especially in patients with unknown EGFR mutation status or patients with squamous cell carcinoma.

Prognostic and predictive value of CEA and CYFRA 21-1 levels in advanced non-small cell lung cancer patients treated with gefitinib or erlotinib

The prognostic and predictive value of pre-treatment serum levels of carcinoembryonic antigen (CEA) and cytokeratin-19 fragments (CYFRA 21-1) were assessed in advanced non-small cell lung cancer (NSCLC) patients treated with gefitinib or erlotinib. Pre-treatment CEA and CYFRA 21-1 levels were measured in 123 advanced NSCLC patients receiving gefitinib or erlotinib. High CEA levels (h-CEA) were significantly associated with females, patients with adenocarcinoma and non-smokers. Low CYFRA 21-1 levels (l-CYFRA 21-1) were significantly associated with a good performance status (ECOG PS 0-1). The overall response rate (RR) was 27.6%, and a higher RR was associated with adenocarcinoma, h-CEA, and epidermal growth factor receptor (EGFR) mutation. Patients with h-CEA had significantly longer progression-free survival (PFS) (P=0.021). Patients with l-CYFRA 21-1 had significantly longer PFS and overall survival (OS) (P=0.006 and P<0.001, respectively). Notably, h-CEA and l-CYFRA 21-1 levels were associated with good prognosis in patients with unknown EGFR mutation status or patients with squamous cell carcinoma (P=0.021 and P=015, respectively). A good ECOG PS (HR=0.45, P=0.017), h-CEA (HR=0.41, P=0.007), l-CYFRA 21-1 (HR=0.52, P=0.025), and an EGFR mutation (HR=0.22, P<0.001) were independently predictive of a longer PFS. A good ECOG PS (HR=0.52, P=0.018), l-CYFRA 21-1 (HR=0.36, P=0.004), and EGFR mutation (HR=0.53, P=0.051) were independently predictive of longer OS. h-CEA and l-CYFRA 21-1 may be prognostic and predictive serum markers for higher response and longer survival in patients with advanced NSCLC receiving gefitinib or erlotinib, particularly in patients with unknown EGFR mutation status or patients with squamous cell carcinoma.

Characteristics of a large cohort of patients with autoimmune pulmonary alveolar proteinosis in Japan

RATIONALE

Acquired pulmonary alveolar proteinosis (PAP) is a syndrome characterized by pulmonary surfactant accumulation occurring in association with granulocyte/macrophage colony-stimulating factor autoantibodies (autoimmune PAP) or as a consequence of another disease (secondary PAP). Because PAP is rare, prior reports were based on limited patient numbers or a synthesis of historical data.

OBJECTIVES

To describe the epidemiologic, clinical, physiologic, and laboratory features of autoimmune PAP in a large, contemporaneous cohort of patients with PAP.

METHODS

Over 6 years, 248 patients with PAP were enrolled in a Japanese national registry, including 223 with autoimmune PAP.

MEASUREMENTS AND MAIN RESULTS

Autoimmune PAP represented 89.9% of cases and had a minimum incidence and prevalence of 0.49 and 6.2 per million, respectively. The male to female ratio was 2.1:1, and the median age at diagnosis was 51 years. A history of smoking occurred in 56%, and dust exposure occurred in 23%; instances of familial onset did not occur. Dyspnea was the most common presenting symptom, occurring in 54.3%. Importantly, 31.8% of patients were asymptomatic and were identified by health screening. Intercurrent illnesses, including infections, were infrequent. A disease severity score reflecting the presence of symptoms and degree of hypoxemia correlated well with carbon monoxide diffusing capacity and serum biomarkers, less well with pulmonary function, and not with granulocyte/macrophage colony-stimulating factor autoantibody levels or duration of disease.

CONCLUSIONS

Autoimmune PAP had an incidence and prevalence higher than previously reported and was not strongly linked to smoking, occupational exposure, or other illnesses. The disease severity score and biomarkers provide novel and potentially useful outcome measures in PAP.

Preoperative Serum Carcinoembryonic Antigen Level is a Prognostic Factor in Women With Early Non–Small-Cell Lung Cancer

BACKGROUND

Carcinoembryonic antigen (CEA) is one of the markers evaluated in patients with non-small cell lung cancer (NSCLC). The significance of the preoperative serum CEA level in female patients with NSCLC is seldom discussed. In this study, we conducted a retrospective review to investigate the prognostic significance of the preoperative CEA level in female patients with stage I NSCLC.

METHODS

In this study, we looked at 163 female patients with stage I NSCLC. Patient charts were reviewed to collect patient data, including the age of the patient, tumor location, tumor size, visceral pleural invasion, the stage of disease, and the preoperative serum CEA level. The cutoff value of serum CEA level was 6.0 ng/mL. The significance of preoperative CEA level in the prognosis of female patients with stage I NSCLC was evaluated.

RESULTS

Among the 163 female patients with stage I NSCLC, 47 patients (28.8%) had abnormal preoperative serum CEA level (>6 ng/mL). Diagnosis of adenocarcinoma and bronchoalveolar carcinoma accounted for 83.4% of these 163 female patients. In-hospital mortality was encountered in 1 patient. Univariate analysis of survival in the other 162 female patients with stage I NSCLC showed that age, stage, tumor size, and preoperative CEA level were prognostic factors. Visceral pleural invasion had no impact on the prognosis of these patients. Multivariate analysis revealed that tumor size and preoperative CEA level were independent prognostic factors in female patients with stage I NSCLC.

CONCLUSIONS

Preoperative serum CEA level and tumor size are independent prognostic factors in female patients with stage I NSCLC. In contrast, visceral pleural invasion was not associated with the prognosis. Importantly, these results suggest that female patients with abnormally high preoperative CEA level and tumor size larger than 3 cm may need a thorough preoperative evaluation and careful postoperative follow-up to rule out occult metastasis of early NSCLC.

Epidemiological and clinical features of idiopathic pulmonary alveolar proteinosis in Japan

Idiopathic pulmonary alveolar proteinosis (IPAP) is a rare disease characterized by excessive amounts of lipoproteinaceous material in the alveolus. This report presents an interim analysis of nationwide epidemiological data from Japanese patients with pulmonary alveolar proteinosis, and the roles of serum markers for IPAP. (i) The nationwide demographic data from 166 Japanese patients with IPAP are shown. The female to male ratio was 1:2, and the average age was 51 +/- 14 years old (age range: 15-79 years) at registration or diagnosis. A total of 30% of patients with IPAP have a poor clinical course. In total, 30% of patients were treated with whole lung lavage therapy (WLL). Under WLL, the patients significantly improved in the short term, but 40% of the patients who underwent WLL worsened again. A new strategy such as granulocyte-macrophage colony-stimulating factor (GM-CSF) therapy for intractable PAP is required. (ii) The correlation of serum KL-6, carcinoembryonic antigen, surfactant proteins D and A, and LDH with disease severity suggests their potential as disease markers. In contrast, serum anti-GM-CSF antibody did not correlate with disease severity, but is a specific marker for the diagnosis of IPAP. The combined measurements of the serum markers may well prove very useful for both the diagnosis and the management of IPAP patients.

Effect of histologic type and smoking status on interpretation of serum carcinoembryonic antigen value in non-small cell lung carcinoma

BACKGROUND

Serum carcinoembryonic antigen (CEA) has all of the properties desired for a biologic measure to be used as a prognostic indicator in the clinical evaluation of lung cancer. Carcinoembryonic antigen value appears to be related to tumor histologic type and patients' smoking status, which has yet to be intensively analyzed as reports available thus far have consisted of a limited number of patients. This study was undertaken to determine whether the prognostic value of CEA differs according to histologic type in a large group of patients with clinical early-stage lung cancer, and how smoking influences its value.

METHODS

Two series of 694 and 260 consecutive patients who underwent resection for clinical stage I lung adenocarcinoma and squamous cell carcinoma, respectively, were evaluated. We measured serum CEA before and after surgery, and analyzed its prognostic significance in relation to histologic type and its correlation with smoking status.

RESULTS

We found significantly higher CEA levels in patients with adenocarcinomas than in those with squamous cell carcinomas (7.8 versus 5.5 ng/mL; p = 0.0018), but a higher percentage of CEA-positive patients among those with squamous cell carcinoma (109 of 260, 41.9%) than those with adenocarcinoma (245 of 694, 35.3%). Clinical stage I patients with a high preoperative CEA level had a poor prognosis, and for pathologically confirmed stage I patients with a high postoperative CEA level the prognosis was worse. The prognostic value of serum CEA level was thus significantly greater for adenocarcinoma than for squamous cell carcinoma. This was probably because of a much higher proportion of smokers among patients with squamous cell carcinoma. In adenocarcinoma, the growth of which was generally less influenced by smoking, the proportion of CEA-positive smokers (49.3%, 170 of 345) was greater than that of CEA-positive nonsmokers (21.5%, 75 of 349, p < 0.0001). Additionally, in patients with adenocarcinoma, survival of nonsmokers was more greatly influenced by CEA level than that of smokers.

CONCLUSIONS

Although serum CEA values measured before and after surgery are important in identifying patients at high risk of poor survival, its specificity is higher for adenocarcinoma than for squamous cell carcinoma. When serum CEA levels are checked, smoking status of patients, particularly of those with squamous cell carcinoma, should be taken into account.

Pulmonary alveolar proteinosis: progress in the first 44 years

Pulmonary alveolar proteinosis is a rare clinical syndrome that was first described in 1958. Subsequently, over 240 case reports and small series have described at least 410 cases in the literature. Characterized by the alveolar accumulation of surfactant components with minimal interstitial inflammation or fibrosis, pulmonary alveolar proteinosis has a variable clinical course ranging from spontaneous resolution to death with pneumonia or respiratory failure. The most effective proven treatment--whole lung lavage--was described soon after the first recognition of this disease. In the last 8 years, there has been rapid progress toward elucidation of the molecular mechanisms underlying both the congenital and acquired forms of pulmonary alveolar proteinosis, following serendipitous discoveries in gene-targeted mice lacking granulocyte-macrophage colony-stimulating factor (GM-CSF). Impairment of surfactant clearance by alveolar macrophages as a result of inhibition of the action of GM-CSF by blocking autoantibodies may underlie many acquired cases, whereas congenital disease is most commonly attributable to mutations in surfactant protein genes but may also be caused by GM-CSF receptor defects. Therapy with GM-CSF has shown promise in approximately half of those acquired cases treated, but it is unsuccessful in congenital forms of the disease, consistent with the known differences in disease pathogenesis.

Influence of smoking on serum carcinoembryonic antigen levels in subjects who underwent multiphasic health testing and services

We quantified the effect of smoking on serum carcinoembryonic antigen (CEA) levels in 1341 subjects who underwent the multiphasic health testing and services in our center. Four hundred and sixty seven of them were smokers and the rest were nonsmokers. In males subjects, serum CEA levels were significantly higher in smokers (3.11 +/- 1.8 ng/ml) than in nonsmokers (2.14 +/- 1.8 ng/ml) (mean +/- SD; p < 0.01). For females, however, the levels had no significant differences between smokers (2.11 +/- 0.91 ng/ml) and nonsmokers (1.87 +2- 1.3 ng/ml). The CEA-positive subjects were 44, of whom 32 were male custom heavy smokers, and only 2 of them had gastrointestinal cancer. We concluded that the serum CEA level was influenced by smoking especially in males and its clinical significance for detection of carcinoma was doubtful.