Prognostic Impact of Elevation of Cancer Antigen 15-3 (CA15-3) in Patients With Early Breast Cancer With Normal Serum CA15-3 Level

• Published in: Journal of breast cancer Vol. 26; no. 2; pp. 126 - 135
• Main Authors: Ryu, Jai Min, Kang, Danbee, Cho, Juhee, Lee, Jeong Eon, Kim, Seok Won, Nam, Seok Jin, Lee, Se Kyung, Kim, Yeon Jin, Im, Young-Hyuck, Ahn, Jin Seok, Park, Yeon Hee, Kim, Ji-Yeon, Lee, Hyunjong, Kang, Mira, Yu, Jong Han
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Breast Cancer Society 01.04.2023
• Subjects: Original; Breast Neoplasms; Survival; Prognosis
• ISSN: 1738-6756; 2092-9900
• DOI: 10.4048/jbc.2023.26.e17

Cancer antigen 15-3 (CA15-3) is a serum tumor marker for breast cancer (BC) extensively used in clinical practice. CA15-3 is non-invasive, easily available, and a cost-effective tumor marker for immediate diagnosis, monitoring and prediction of BC recurrence. We hypothesized that an elevation of CA15-3 may have prognostic impact in patients with early BC with normal serum CA15-3 level. This was a retrospective cohort study, which included patients with BC who received curative surgery at a comprehensive single institution between 2000 and 2016. CA15-3 levels from 0 to 30 U/mL were considered normal, and patients who had CA15-3 > 30 U/mL, were excluded from the study. The mean age of study participants (n = 11,452) was 49.3 years. The proportion of participants with elevated CA15-3 ≥ 1 standard deviation (SD) compared with the previous examination during follow-up was 23.3% (n = 2,666). During the follow-up (median follow-up 5.8 years), 790 patients experienced recurrence. The fully-adjusted hazard ratio (HR) for recurrence comparing participants with stable CA15-3 level to subjects with elevated CA15-3 level was 1.76 (95% confidence interval [CI], 1.52-2.03). In addition, if the CA15-3 was elevated ≥ 1 SD, the risk was much higher (HR, 6.87; 95% CI, 5.81-8.11) than in patients without elevated CA15-3 ≥ 1 SD. In sensitivity analysis, the recurrence risk was consistently higher in participants with elevated CA15-3 levels than in participants without elevated CA15-3 levels. The association between elevated CA15-3 levels and incidence of recurrence was observed in all subtypes and the association was stronger in patients with N+ than in patients with N0 stage ( -value for interaction < 0.01). The results of the present study demonstrated that elevation of CA15-3 in patients with early BC and initial normal serum CA15-3 levels has a prognostic impact.