<![CDATA[Abstract: Colorectal cancer is the third most common cancer in Indonesia with a mortality rate at fourth rank. A balance between systemic inflammation and immunity is necessary in the stratification of risk, treatment, and prognosis of various cancers. This study aimed to determine the relationship between neutrophil-to lymphocyte ratio (NLR) and carcinoembryonic antigen (CEA) in the survival of post-operative colorectal cancer patients. This was a retrospective hospital-based cohort study using the R statistical analysis tool version 4.2.2. The results obtained 88 colorectal cancer patients with histopathologically confirmed. Most were nearly 60 years old, with a relatively balanced proportion of men and women. The median of resected mass size was around 6 cm, 80% of tumors located in the rectum and rectosigmoid, a balanced proportion of stage II and III (44%), moderate differentiation (86%), with decreased NLR post-operation (median of 3,8 to 2,6), and decrased CEA post-operation (median 8,6 to 6,3). In conclusion, there is a positive correlation between NLR and CEA level, however, it is limited until three months post operation. After three months, the correlation is undetected anymore. Keywords: neutrophil-to-lymphocyte ratio; carcinoembryonic antigen; colorectal cancer; pre and post operation  Abstrak: Kanker kolorektal merupakan keganasan ketiga terbanyak di dunia dengan angka mortalitas urutan ke-empat. Keseimbangan antara peradangan sistemik dan imunitas diperlukan dalam stratifikasi risiko, pengobatan, dan prognosis berbagai jenis keganasan. Penelitian ini bertujuan untuk mengetahui hubungan antara neutrophil-to lymphocyte ratio (NLR) dan kadar carcinoembryonic antigen (CEA) pada kesintasan pasien kanker kolorektal pasca operasi. Jenis penelitian ialah kohort retrospektif berbasis rumah sakit dengan alat analisis statistik R versi 4.2.2. Hasil penelitian mendapatkan 88 pasien terkonfirmasi histopatologik kanker kolon rektal, berusia hampir 60 tahun, proporsi laki-laki dan perempuan relatif berimbang, median ukuran masa yang direseksi sekitar 6 cm, 80% tumor terletak di daerah rektum dan rektosigmoid, stadium II dan III presentasi berimbang (44%), diferensiasi sedang (86%), NLR menurun pada pasca operasi (median 3,8 menjadi 2,6), dan CEA menurun pada pasca operasi (median 8,6 menjadi 6,3). Simpulan penelitian ini ialah terdapat hubungan positif antara neutrophil-to-lymphocyte ratio (NLR) dan kadar carcinoembryonic antigen (CEA), tetapi hanya terbatas sampai tiga bulan pasca operasi. Korelasi keduanya tidak terdeteksi lagi setelah tiga bulan pasca operasi. Kata kunci: neutrophil-to-lymphocyte ratio; carcinoembryonic antigen: kanker kolon rektal; pre dan pasca operasi]]>
