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Establishing reference interval of serum CA-125 for the healthy Han population in China
Guo-Ming Zhang1, Tao Wang1, Bing Gu2,3
1Department of Laboratory Medicine, The Affiliated Shuyang Hospital of Xuzhou Medical University, Shuyang Hospital, Shuyang, China.
Insights
This study established new sex- and age-specific reference intervals for serum cancer antigen 125 (CA-125) in healthy Han Chinese adults. These updated CA-125 reference ranges may enhance diagnostic accuracy for ovarian cancer in this population.
Area of Science:
- Clinical Chemistry
- Oncology
- Biomarker Research
Background:
- Serum cancer antigen 125 (CA-125) is a key biomarker for ovarian cancer diagnosis and monitoring.
- Existing CA-125 reference intervals can vary significantly across different populations.
- Establishing population-specific reference ranges is crucial for accurate clinical interpretation.
Purpose of the Study:
- To determine sex- and age-specific reference intervals for serum CA-125 in healthy Han Chinese adults.
- To provide updated reference values for improved clinical utility in routine health checks.
- To follow CLSI C28-A3 guidelines for establishing laboratory test reference ranges.
Main Methods:
- Analysis of health check records from 10,076 Han Chinese adults (aged 18-90 years).
- Exclusion of individuals with chronic diseases, infections, or abnormal related lab tests.
- Serum CA-125 measurement using a Beckman Coulter DxI 800 chemiluminescent immunoassay.
- Statistical outlier removal and reference limit estimation following CLSI recommendations.
Main Results:
- A cohort of 9,871 healthy Han Chinese adults (7,688 females, 2,183 males) was analyzed.
- The upper reference limit for CA-125 in men was 19.7 U/mL.
- In women, CA-125 levels were higher than in men and decreased with age (upper limits: 33.1 U/mL for 18-30 yrs, 28.1 U/mL for 31-70 yrs, 21.8 U/mL for 71-90 yrs).
Conclusions:
- Sex- and age-specific reference intervals for serum CA-125 were successfully established for Han Chinese adults.
- The findings indicate a decrease in CA-125 with age in women, while levels remain stable in men.
- These locally derived reference intervals may improve CA-125 interpretation but require validation in other populations and assay systems.
Background:
Serum cancer antigen 125 (CA-125) is widely used in the diagnosis and follow-up of ovarian cancer, but its reference interval may vary between populations. We aimed to establish sex- and age-specific reference intervals for serum CA-125 in healthy Han Chinese adults receiving routine health checks, following CLSI C28-A3 guidance.
Methods:
We reviewed health-check records from Shuyang Hospital and identified 10,076 Han Chinese adults aged 18-90 years whose serum CA-125 concentration was measured between October 2018 and December 2023. Individuals with self-reported or clinically documented chronic diseases, acute infection, pregnancy or abnormal results in complete blood count, liver and renal function tests, fasting plasma glucose or C-reactive protein were excluded. Serum CA-125 was measured on a DxI 800 chemiluminescent immunoassay analyser (Beckman Coulter). Statistical outliers were identified within sex and age partitions via Tukey's rule and, where needed, the Dixon test. Reference limits and 90% confidence intervals were estimated according to CLSI recommendations.
Results:
After applying the clinical and laboratory criteria and removing 170 statistical outliers, 9,871 apparently healthy Han adults (7,688 females and 2,183 males) remained for analysis. The upper reference limit for CA-125 in men was 19.7 U/mL. In women, CA-125 concentrations were higher than those in men and were negatively correlated with age (Spearman r = - 0.2488, P < 0.001). The upper reference limits were 33.1 U/mL for women aged 18-30 years, 28.1 U/mL for those aged 31-70 years and 21.8 U/mL for those aged 71-90 years.
Conclusions:
Using a large health-check cohort and CLSI-based methodology, we established sex-specific and age-specific reference intervals for serum CA-125 in Han Chinese adults via the Beckman DxI 800 platform. In this population, CA-125 tends to decrease with age in women and remains relatively stable in men. These locally derived intervals may improve the interpretation of CA-125 in Han adults but should be verified in other centers, assay systems and ethnic groups.
