Tesis

Korelasi Pemeriksaan HER2 Circulating Tumor Cell dan Jaringanpada Kasus Kanker Payudara = Correlation Between HER2 Expression in Circulating Tumor Cells andTumor Tissue in Breast Cancer.

Latar Belakang: Penentuan status HER2 merupakan komponen penting dalam diagnosisdan tatalaksana kanker payudara karena berimplikasi terhadap prognosis dan terapi. Bakuemas pemeriksaan HER2 dilakukan melalui biopsi jaringan, namun bersifat invasif danmemiliki keterbatasan akibat heterogenitas tumor. Pemeriksaan berbasis darah melaluicirculating tumor cell (CTC) sebagai bagian dari biopsi cair bersifat metode non-invasif,namun korelasinya dengan pemeriksaan jaringan masih terbatas.Tujuan: Mengetahui korelasi antara hasil pemeriksaan HER2 pada darah dengan hasilpemeriksaan HER2 pada jaringan tumor pasien kanker payudara.Metode: Penelitian ini menggunakan desain potong lintang yang dilakukan di RSUPNCipto Mangunkusumo pada periode Mei 2025–Mei 2026. Sampel terdiri dari 45 pasienkanker payudara yang memenuhi kriteria inklusi. Pemeriksaan HER2 jaringan dilakukandengan imunohistokimia/CISH-FISH, sedangkan HER2 CTC darah diperiksamenggunakan flow cytometry. Analisis korelasi dilakukan menggunakan uji Spearman.Hasil: Rerata usia subjek adalah 51,96±9,81 tahun dengan mayoritas stadium III.Didapatkan korelasi kuat antara HER2 CTC darah dan HER2 jaringan (r=0,762;p < 0,001). Median kadar HER2 darah lebih tinggi secara bermakna pada kelompok HER2positif dibandingkan HER2 negatif (2,35 vs 0,285; p < 0,001).Kesimpulan: Terdapat korelasi yang kuat dan bermakna antara pemeriksaan HER2 padaCTC darah dan jaringan tumor pada kanker payudara. Pemeriksaan HER2 berbasis darahberpotensi menjadi metode non-invasif yang dapat melengkapi evaluasi status HER2dalam praktik klinis.
Kata Kunci: kanker payudara, HER2, circulating tumor cell, biopsi cair, korelasi.


Background: Determination of HER2 status is a crucial component in the diagnosis andmanagement of breast cancer due to its prognostic and therapeutic implications. Tissuebiopsy remains the gold standard for HER2 assessment; however, it is invasive andlimited by tumor heterogeneity. Liquid biopsy using circulating tumor cells (CTCs) offersa minimally invasive alternative, yet its correlation with tissue-based HER2 assessmentremains unclear.Objective: To determine the correlation between the results of HER2 examination inblood and the results of HER2 examination in tumor tissue of breast cancer patients.Methods: This cross-sectional study was conducted at Cipto Mangunkusumo NationalGeneral Hospital between May 2025 and May 2026. A total of 45 breast cancer patientsmeeting the inclusion criteria were enrolled. HER2 status in tumor tissue was assessedusing immunohistochemistry and/or CISH/FISH, while HER2 expression in CTCs wasevaluated using flow cytometry. Correlation analysis was performed using Spearman’stest.Results: The mean age of subjects was 51.96 ± 9.81 years, with the majority presentingat stage III. A strong positive correlation was found between HER2 expression in CTCsand tumor tissue (r = 0.762; p < 0.001). The median HER2 level in blood was significantlyhigher in the HER2-positive group compared to the HER2-negative group (2.35 vs 0.285;p < 0.001).Conclusion: There is a strong and statistically significant correlation between HER2expression in circulating tumor cells and tumor tissue in breast cancer patients. Bloodbased HER2 assessment has the potential to serve as a minimally invasive adjunct inevaluating HER2 status in clinical practice.
Keywords: breast cancer, HER2, circulating tumor cells, liquid biopsy, correlation.