Jeonghyun Kang

Background Carcinoembryonic antigen (CEA) and sarcopenia, defined as a low skeletal muscle index (SMI), are established prognostic factors in colorectal cancer (CRC). We evaluated the prognostic value of the preoperative CEA-to-SMI ratio (CSR), an index integrating tumor burden and host physiological reserve. Methods We retrospectively analyzed 1,033 patients who underwent curative surgery for CRC. SMI (cm²/m²) was measured on preoperative computed tomography at the third lumbar vertebra, and patients were stratified into CSR quartiles (Q1–Q4). The primary endpoint was overall survival (OS). Independent prognostic factors were identified by multivariable Cox regression, and discrimination was compared with that of CEA and SMI alone using Harrell's concordance index (C-index). Results Five-year OS decreased stepwise as the CSR increased: 93.4% (Q1), 86.8% (Q2), 83.2% (Q3) and 76.6% (Q4) ( P < 0.001). On multivariable analysis the CSR remained an independent prognostic factor, with Q4 carrying a higher risk of death than Q1 (hazard ratio 2.650, 95% confidence interval 1.610–4.360; P < 0.001). The C-index of the CSR (0.625) was higher than that of CEA alone (0.574, P < 0.001) or SMI alone (0.574, P = 0.039). Adding the CSR to a base clinical model improved the C-index from 0.714 to 0.728 ( P = 0.041). Conclusion The preoperative CSR is a potentially useful independent prognostic indicator in CRC, providing additive risk stratification beyond CEA or SMI alone and enabling identification of high-risk patients in clinical practice.

Korean Practical Guidelines for Geriatric Assessment and Management of Older Adults with Cancer: A Korean Cancer Association Guideline for Geriatric Oncology

Kang J. Ann Surg Treat Res. 2026 Apr;110(4):203-204. https://doi.org/10.4174/astr.2026.110.4.203

Lee JW, et al. Ann Surg Treat Res. 2026 Mar;110(3):170-179. https://doi.org/10.4174/astr.2026.110.3.170

Skeletal Muscle Index to Red Cell Distribution Width Ratio: A Novel Prognostic Indicator for Patients with Stage I-III Colorectal Cancer

Purpose: Although carbohydrate antigen 19-9 (CA19-9) may exhibit low sensitivity in tumor screening, its prognostic significance has been highlighted. This study assessed the significance of preoperative CA19-9 and early postoperative CA19-9 levels in patients with nonmetastatic colorectal cancer (CRC).Methods: Patients diagnosed with stage I–III CRC between January 2004 and April 2014 were included. Preoperative CA19-9 was assessed within 2 months of operation, whereas postoperative CA19-9 was measured 4 to 7 days after operation. The optimal cutoff values for preoperative and postoperative CA19-9 were established to maximize the differences in overall survival. Patients were categorized into 3 groups based on the CA19-9 change (CA19-9 trend): group 1, low preoperative CA19-9; group 2, high preoperative and low postoperative CA19-9; and group 3, high preoperative and postoperative CA19-9. The discriminatory powers of all variables were compared using the concordance index.Results: A total of 816 patients were included. The determined cutoff values for preoperative and postoperative CA19-9 were 18.9 and 21.4 U/mL, respectively. Subgroup dichotomization revealed associations of preoperative CA19-9, postoperative CA19-9, and CA19-9 trend with overall survival in univariable analysis. The CA19-9 trend emerged as an independent prognostic factor in the multivariable analysis (group 1 vs. group 2: hazard ratio, 1.682 [95% confidence interval (CI), 1.043–2.710], P=0.032; group 1 vs. group 3: hazard ratio, 2.882 [95% CI, 1.899–4.371], P<0.001). The concordance index value of the CA19-9 trend (0.636; 95% CI, 0.509–0.682) surpassed those of preoperative and postoperative CA19-9.Conclusion: The amalgamation of preoperative and postoperative CA19-9 levels demonstrated enhanced prognostic stratification, allowing for a more detailed classification of patients with nonmetastatic CRC.

Purpose: While preoperative prognostic nutritional index (PNI) is a well-established prognostic marker in colorectal cancer (CRC), and postoperative PNI has gained attention, their combined prognostic value remains largely unexplored. Patients and Methods: We analyzed patients who underwent curative surgery for stage I–III CRC between March 2004 and February 2014. The pre- and postoperative PNI, measured within 1 month before and 3– 8 weeks after surgery, were combined to create “change-PNI” The Cox proportional hazards model was used to assess the prognostic significance, and the C-index was compared across values. Results: The optimal pre- and postoperative PNI cutoff values predicting 5-year overall survival (OS) were 48.05 and 43.65, respectively. The patients were categorized into four groups based on their pre- and postoperative values: pre-low + post-low (G1), pre-low + post-high (G2), pre-high + post-low (G3), and pre-high + post-high (G4). A multivariable Cox proportional hazards model demonstrated that patients in G2, G3, and G4 had significantly lower mortality risks than those in G1 (HR [95% CI] vs G1: G2, 0.341 [0.186– 0.625]; G3, 0.457 [0.222– 0.941]; G4, 0.222 [0.123– 0.401]). The C-index of change-PNI (0.671, 95% CI 0.617– 0.720) was superior to that of preoperative PNI (0.609, 95% CI 0.563– 0.654) (bootstrap mean difference: 0.062, 95% CI 0.029– 0.099) and postoperative PNI (0.622, 95% CI 0.581– 0.664) (bootstrap mean difference: 0.049, 95% CI 0.014– 0.085). Conclusion: Change-PNI serves as a more effective independent immuno-nutritional marker than pre- or postoperative PNI in predicting OS in patients undergoing surgery for non-metastatic colorectal cancer.