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Updated: Apr 21, 2026
Serum and Plasma Copy Number Detection Using Real-time PCR
Published on: December 15, 2017
Increases in serum CYFRA21-1 concentration during successful treatment with crizotinib
Nobuhiro Kanaji1, Akira Tadokoro1, Naoki Watanabe1
1Department of Internal Medicine, Division of Hematology, Rheumatology and Respiratory Medicine, Faculty of Medicine, Kagawa University, Kagawa, Japan.
Background:
Increases in tumor marker concentrations usually suggest disease progression.
Case Report:
We here describe on 3 patients with non-small cell lung cancer whose serum concentrations of CYFRA21-1 increased in spite of successful treatment with crizotinib. Discontinuation of crizotinib resulted in a rapid decrease in serum CYFRA21-1 concentrations in all cases. In 1 patient with progressive disease, in spite of increasing the dose of crizotinib, CYFRA21-1 concentrations decreased.
Conclusions:
Crizotinib can induce increases in CYFRA21-1 concentration without disease progression. Pulmonologists and oncologists should be aware of this novel phenomenon, and focus on interpretation of CYFRA21-1 concentrations in monitoring tumor response to crizotinib treatment.
