Electronic Theses and Dissertation

Kanker kolorektal masih menjadi salah satu masalah kesehatan utama, sementara metode skrining noninvasif yang akurat dan terjangkau masih terbatas. Fecal secondary bile acid, khususnya deoxycholic acid (DCA) dan lithocholic acid (LCA), berpotensi menjadi penanda biologis kanker kolorektal, termasuk bila dikombinasikan dengan carcinoembryonic antigen (CEA). Penelitian ini bertujuan menganalisis sensitivitas dan spesifisitas DCA feses, LCA feses, CEA serum, serta kombinasinya sebagai penanda biologis untuk skrining kanker kolorektal, serta hubungannya dengan stadium penyakit. Penelitian observasional analitik dengan desain case-control ini melibatkan 40 subjek, terdiri atas 20 pasien kanker kolorektal dan 20 kontrol. Kadar DCA dan LCA feses diperiksa dengan liquid chromatography–mass spectrometry, sedangkan kadar CEA serum diperiksa dengan electrochemiluminescence immunoassay. Performa penanda biologis dianalisis menggunakan kurva ROC, sedangkan hubungannya dengan stadium dinilai menggunakan korelasi Spearman. Kadar DCA, LCA, dan CEA secara bermakna lebih tinggi pada kelompok kanker kolorektal dibandingkan dengan kontrol (p0,05). Disimpulkan bahwa DCA feses, LCA feses, CEA serum, dan kombinasinya menunjukkan performa yang cukup baik sebagai penanda biologis untuk skrining kanker kolorektal, dengan hasil terbaik pada model kombinasi.

Colorectal cancer remains a major health problem, while accurate, affordable non-invasive screening methods remain limited. Fecal secondary bile acids, particularly deoxycholic acid (DCA) and lithocholic acid (LCA), may serve as biomarkers for colorectal cancer, alone or combined with carcinoembryonic antigen (CEA). This study aimed to analyze the sensitivity and specificity of fecal DCA, fecal LCA, serum CEA, and their combination as biomarkers for colorectal cancer screening, as well as their association with disease stage. This analytical observational study with a case-control design involved 40 subjects; 20 patients with colorectal cancer and 20 controls. Fecal DCA and LCA levels were measured using liquid chromatography–mass spectrometry, whereas serum CEA levels were measured using electrochemiluminescence immunoassay. Biomarker performance was analyzed using ROC curve analysis, and its association with disease stage was evaluated using Spearman correlation. DCA, LCA, and CEA levels were significantly higher in the colorectal cancer group than in controls (p0.05). In conclusion, fecal DCA, fecal LCA, serum CEA, and their combination showed performance as biomarkers for colorectal cancer screening, with the best results observed in the combined model.