Predictive value of magnetic resonance imaging parameters combined with tumor markers for rectal cancer recurrence risk after surgery.

Background: An increasing number of studies to date have found preoperative magnetic resonance imaging (MRI) features valuable in predicting the prognosis of rectal cancer (RC). However, research is still lacking on the correlation between preoperative MRI features and the risk of recurrence after radical resection of RC, urgently necessitating further in-depth exploration.

Aim: To investigate the correlation between preoperative MRI parameters and the risk of recurrence after radical resection of RC to provide an effective tool for predicting postoperative recurrence.

Methods: The data of 90 patients who were diagnosed with RC by surgical pathology and underwent radical surgical resection at the Second Affiliated Hospital of Bengbu Medical University between May 2020 and December 2023 were collected through retrospective analysis. General demographic data, MRI data, and tumor markers levels were collected. According to the reviewed data of patients six months after surgery, the clinicians comprehensively assessed the recurrence risk and divided the patients into high recurrence risk (37 cases) and low recurrence risk (53 cases) groups. Independent sample t-test and χ ² test were used to analyze differences between the two groups. A logistic regression model was used to explore the risk factors of the high recurrence risk group, and a clinical prediction model was constructed. The clinical prediction model is presented in the form of a nomogram. The receiver operating characteristic curve, Hosmer-Lemeshow goodness of fit test, calibration curve, and decision curve analysis were used to evaluate the efficacy of the clinical prediction model.

Results: The detection of positive extramural vascular invasion through preoperative MRI [odds ratio (OR) = 4.29, P = 0.045], along with elevated carcinoembryonic antigen (OR = 1.08, P = 0.041), carbohydrate antigen 125 (OR = 1.19, P = 0.034), and carbohydrate antigen 199 (OR = 1.27, P < 0.001) levels, are independent risk factors for increased postoperative recurrence risk in patients with RC. Furthermore, there was a correlation between magnetic resonance based T staging, magnetic resonance based N staging, and circumferential resection margin results determined by MRI and the postoperative recurrence risk. Additionally, when extramural vascular invasion was integrated with tumor markers, the resulting clinical prediction model more effectively identified patients at high risk for postoperative recurrence, thereby providing robust support for clinical decision-making.

Conclusion: The results of this study indicate that preoperative MRI detection is of great importance for predicting the risk of postoperative recurrence in patients with RC. Monitoring these markers helps clinicians identify patients at high risk, allowing for more aggressive treatment and monitoring strategies to improve patient outcomes.