To investigate the effect of a new combined inflammatory-nutritional serum marker, (platelet×albumin) to lymphocyte ratio (PALR), on lymph node metastasis in colorectal cancer (CRC), and to establish a clinically applicable risk prediction model for column line drawing.

The clinical data of 235 CRC radical surgery patients in Zhongshan City People’s Hospital from July 2022 to July 2023 were collected, and the study subjects were randomly divided into the training set and the validation set according to the ratio of 7∶3. A single-factor analysis was used to initially screen the factors associated with CRC lymph node metastasis, and then a column-line graph prediction model was developed based on the independent risk factors identified by multifactor logistic regression analysis, and a validation set was used to internally validate the model, and receiver operating characteristic (ROC) curves, calibration plots, and decision analytic curves.

Patients in the training set were divided into metastasis positive group (116 cases) and metastasis negative group (48 cases) based on their lymph node metastasis status. The results of regression analysis showed that PALR, systemic immune-inflammation index (SII), carcinoembryonic antigen (CEA) level, degree of tumor differentiation, preoperative intestinal obstruction, and enhanced CT report of lymph node metastasis were all significantly correlated with the occurrence of lymph node metastasis in CRC patients (P<0.05). The areas under the curve of the training and validation sets of the model were 0.868 (95% CI: 0.813-0.922) and 0.854 (95% CI: 0.763-0.946), respectively, and the validation results of the model in the validation set showed that the calibration curves were in good agreement with the actual observed values, and meanwhile, the assessment based on the decision curves confirmed that the predictive tool had a higher practical value.

The nomogram prediction model based on PALR provides a key tool for CRC patients to assess the risk of lymph node metastasis before surgery, which is helpful to provide useful reference and support for personalized and precise treatment plans for patients.