Hubungan antara Ekspresi Ki-67 dan Disease Free Survival pada Pasien Triple Negative Breast Cancer Operable; Perbandingan Pemeriksaan dengan Imunohistokimia dan qRT-PCR

Andreas P.T.Y. Hutapea, dr. Paranita Ferronika, Ph.D. Sp.PA., Subsp.KA (K).; Dr. dr. R. Artanto Wahyono, Sp.B. Subsp. Onk (K).; Dr.rer.nat. dr. Dyah Laksmi Dewi, M.Sc., Sp.B.

2026 | Skripsi | PENDIDIKAN DOKTER

Latar belakang: Kanker payudara menempati peringkat pertama sebagai jenis kanker yang terdiagnosis di Indonesia. Triple negative breast cancer (TNBC) memiliki perilaku biologi sangat invasif, gradasi dan indeks mitosis yang tinggi, agresif serta prognosis yang buruk. Gen Ki-67 berperan sebagai indeks proliferasi dan faktor prognosis TNBC operable. Ekspresi gen Ki-67 melalui uji qRT-PCR lebih terstandarisasi dalam perhitungan dan minimal bias pemrosesan dibandingkan dengan imunohistokimia (IHK). Oleh karena itu ekspresi gen ki-67 melalui uji qRT-PCR berpotensi digunakan sebagai penentuan prognosis pada TNBC operable.

Tujuan: Membandingkan metode Immunohistokimia dan qRT-PCR dalam menganalisis pengaruh ekspresi Ki-67 terhadap Disease Free Survival (DFS) pada Triple Negatif Breast Cancer (TNBC) Operable.

Metodologi penelitian: Penelitian ini melibatkan pasien TNBC yang berobat di Departemen Bedah Onkologi RSUP Dr. Sardjito dengan desain penelitian non-experimental analytic dengan pendekatan metodologi cohort retrospektif. Ekspresi ki-67 pada spesimen jaringan tumor diperiksa secara IHK dengan antibodi monoklonal anti-Ki-67 dan qRT-PCR. Analisis Survival dengan kurva Kaplan-Meier membandingkan ekspresi Ki-67 IHK dan qRT-PCR terhadap Disease free survival. Uji diskordansi dilakukan dengan uji McNemar.

Hasil: Sampel penelitian sejumlah 54 pasien dengan karakteristik 3 pasien (94,4%) dengan ekspresi Ki-67 IHK rendah dan 51 pasien (5,6%) tinggi. 15 pasien (27,8%) dengan ekspresi Ki-67 qRT-PCR rendah dan 39 pasien (72,2%) tinggi. Median survival pasien dengan ekspresi Ki-67 IHK tinggi adalah 122 minggu, median survival pasien dengan ekspresi Ki-67 qRT-PCR tinggi adalah 51,3 minggu. Terdapat diskordansi antara nilai ekspresi Ki-67 IHK dan qRT-PCR pada uji McNemar p = 0.003 (p<0 lang="EN-US">

Kesimpulan: Tidak terdapat pengaruh Ki-67 IHK dengan DFS, terdapat pengaruh Ki-67 qRT-PCR terhadap DFS, dan diskordan antara Ki-67 IHK dan qRT-PCR.

Background: Breast cancer ranks first as the most frequently diagnosed cancer in Indonesia. Triple-negative breast cancer (TNBC) exhibits highly invasive biological behavior, high histological grade and mitotic index, aggressive nature, and poor prognosis. The Ki-67 gene functions as a proliferation index and prognostic factor in operable TNBC. Measurement of Ki-67 gene expression using quantitative real-time PCR (qRT-PCR) is more standardized and has minimal processing bias compared to immunohistochemistry (IHC). Therefore, Ki-67 gene expression assessed by qRT-PCR has potential value for prognostic determination in operable TNBC.

Objective: To compare immunohistochemistry (IHC) and qRT-PCR methods in analyzing the effect of Ki-67 expression on Disease-Free Survival (DFS) in operable Triple-Negative Breast Cancer (TNBC).

Methods: This study involved TNBC patients treated at the Department of Surgical Oncology, Dr. Sardjito General Hospital, using a non-experimental analytic design with a retrospective cohort approach. Ki-67 expression in tumor tissue specimens was assessed using IHC with monoclonal anti–Ki-67 antibodies and by qRT-PCR. Survival analysis using Kaplan–Meier curves compared Ki-67 expression measured by IHC and qRT-PCR with Disease-Free Survival. Discordance between the two methods was analyzed using the McNemar test.

Results: A total of 54 patients were included in this study. Based on IHC, 3 patients (5.6%) showed low Ki-67 expression and 51 patients (94.4%) showed high Ki-67 expression. Based on qRT-PCR, 15 patients (27.8%) had low Ki-67 expression and 39 patients (72.2%) had high expression. The median survival of patients with high Ki-67 expression measured by IHC was 122 weeks, while the median survival of patients with high Ki-67 expression measured by qRT-PCR was 51.3 weeks. Discordance between Ki-67 expression values obtained by IHC and qRT-PCR was statistically significant based on the McNemar test (p = 0.003; p < 0>

Conclusion: Ki-67 expression assessed by IHC showed no significant association with DFS, whereas Ki-67 expression assessed by qRT-PCR significantly affected DFS. There was discordance between Ki-67 expression results obtained by IHC and qRT-PCR.

Kata Kunci : Kata kunci: Ki-67, Triple Negative Breast Cancer (TNBC) Operable, Imunohistokimia (IHK), qRT-PCR, Disease Free Survival (DFS).