Variability of serum CYFRA 21 - 1 and its susceptibility to clinical characteristics in individuals without cancer: a 4-year retrospective analysis.

BACKGROUND: CYFRA 21 - 1 is a useful marker for diagnosing and monitoring lung cancer. However, its stability remains unclear. Moreover, while its applicability to screening is now being investigated, CYFRA 21 - 1 levels in individuals without cancer, who are targets for cancer screening, have not yet been the focus of research. Therefore, the present study investigated variability in and the factors increasing serum CYFRA 21 - 1 levels. METHODS: This retrospective study recruited 951 individuals undergoing annual medical examinations for six years. We used data obtained in the first four years. Variability in serum CYFRA 21 - 1 levels over a period of four years were investigated. CYFRA 21 - 1 was categorized as normal (≤ 3.5 ng/ml) or elevated (> 3.5 ng/ml). The rate of an elevated level in one visit and the transition from an elevated to normal level between visits were visualized. A multiple logistic regression model was used to study the relationships between the frequency of elevated CYFRA 21 - 1 levels and clinical characteristics, such as age, sex, body mass index, weight changes, and the smoking status. RESULTS: Approximately 5% of subjects had elevated CYFRA 21 - 1 levels once in five tests over four years, while 15% had elevated CYFRA 21 - 1 levels once or more. Among subjects with elevated CYFRA 21 - 1 levels in one blood test, between 63 and 72% had normal levels in the next test. The median CYFRA 21 - 1 level in subjects with elevations in one blood test significantly decreased in the next test at all four time points. The frequency of elevated CYFRA 21 - 1 levels was associated with an older age [odds ratio (OR) = 6.99, 95% confidence interval (CI) = 3.01-16.2], current heavy smoking (OR = 3.46, 95% CI = 1.52-7.9), and weight loss (OR = 1.86, 95% CI = 1.07-3.24). CONCLUSIONS: Variability in and the factors increasing serum CYFRA 21 - 1 levels beyond the cut-off value need to be considered when interpretating CYFRA 21 - 1 test results. The future application of CYFRA 21 - 1 to lung cancer screening may require more than a single measurement.

Possibility of Venous Serum Cl- Concentration ([Cl-]s) as a Marker for Human Metabolic Status: Correlation of [Cl-]s to Age, Fasting Blood Sugar (FBS), and Glycated Hemoglobin (HbA1c).

The HCO3- concentration in venous serum ([HCO3-]s) is a factor commonly used for detecting the body pH and metabolic conditions. To exactly detect [HCO3-]s, the venous CO2 pressure should be kept as it is in the vein. The [HCO3-]s measurement is technically complicated to apply for huge numbers of almost heathy persons taking only basic medical examinations. The summation of [HCO3-]s and the venous serum Cl- concentration ([Cl-]s) is approximately constant; therefore, we studied if [Cl-]s could be a marker detecting metabolic conditions instead of [HCO3-]s. Venous blood was obtained from persons taking basic medical examinations (the number of persons = 107,630). Older persons showed higher values of [Cl-]s, fasting blood sugar (FBS), and glycated hemoglobin (HbA1c) than younger ones. [Cl-]s showed positive correlation to age and negative correlation to FBS and HBA1c. The negative correlation of [Cl-]s to FBS/HbA1c was obvious in persons with high FBS/HbA1c, leading us to an idea that persons with high FBS/HbA1c show high [HCO3-]s, which might be caused by low activity of carbonic anhydrase in the lung observed in persons with diabetes mellitus under acidotic conditions. Taken together, an easily measured serum electrolyte, [Cl-]s, could be a useful marker estimating metabolic conditions.

Age and Smoking Status Affect Serum Cytokeratin 19 Fragment Levels in Individuals Without Cancer.

BACKGROUND/AIM: Lung cancer is a frequent and fatal cancer that is difficult to diagnose in the early stages. CYFRA 21-1 is a serological marker currently used to diagnose and monitor lung cancer; however, its clinical use for screening is controversial. Therefore, the present study investigated the relationship between serum CYFRA 21-1 levels and clinical confounders. PATIENTS AND METHODS: We recruited 3,674 individuals who had never been diagnosed with any cancer. The relationships between high serum CYFRA 21-1 levels (≥3.5 ng/ml) and age, sex, body mass index, and smoking status were investigated. RESULTS: High serum CYFRA 21-1 levels (≥3.5 ng/ml) were detected in 5.1% of all subjects. High serum CYFRA 21-1 levels were observed in 7.3% of current smokers and 4.3% of non-smokers. The proportion of subjects with high serum CYFRA 21-1 levels was markedly higher in the older group (65 years and older, 11%) than in the younger group (younger than 45 years, 2.0%). High serum CYFRA 21-1 levels (≥3.5 ng/ml) were associated with older age [odds ratio (OR)=3.39, 95% confidence interval (CI)=1.79-6.41 for 55-64 years vs. <45 years, and OR=7.34, 95% CI=3.86-13.9 for ≥65 years vs. <45 years, respectively] and current smoking (OR=2.09, 95% CI=1.38-3.15 for current smoker vs. non-smoker). CONCLUSION: High serum CYFRA 21-1 levels were associated with an older age and current smoking, which may be considered as factors influencing CYFRA 21-1 levels.