Dynamic monitoring of perioperative plasma SAA2 levels: association with treatment efficacy and prognosis in NSCLC patients

To explore the clinical value of dynamic monitoring of perioperative plasma serum amyloid A2 (SAA2) levels in evaluating surgical efficacy and predicting long-term prognosis in patients with non-small cell lung cancer (NSCLC).​ A total of 70 patients with NSCLC who underwent surgical treatment in our department from January 2018 to June 2022 were enrolled retrospectively. Peripheral blood samples were collected at four time points: 1 day before surgery (T0), 1 day after surgery (T1), 7 days after surgery (T2), and 1 month after surgery (T3). The plasma concentration of serum amyloid A2 (SAA2) was determined using the enzyme-linked immunosorbent assay (ELISA). Meanwhile, the clinicopathological characteristics of the patients were recorded, and regular follow-up was performed to analyze disease-free survival (DFS) and overall survival (OS). The optimal cut-off value of SAA2 level was determined based on the receiver operating characteristic (ROC) curve, and internal validation was performed using Bootstrap resampling. Preoperative plasma SAA2 levels in NSCLC patients were significantly higher than those in the healthy control group ( P < 0.01) and were associated with lymph node metastasis of lung cancer ( P < 0.01). SAA2 levels peaked sharply at T1 post-surgery. For patients with good postoperative recovery, their SAA2 levels began to decrease significantly at T2 and approached or returned to normal levels at T3. Survival analysis showed that patients whose SAA2 levels did not return to normal (defined as ≥ cutoff value of 18.3 µg/mL) at 1 month after surgery had significantly worse DFS (HR = 9.200, 95% CI: 4.666–18.139) and OS (HR = 6.977, 95% CI: 3.311–14.704) than those with normalized SAA2 levels. The median DFS was 15.72 months in the high-expression group vs. 32.85 months in the normal group; the median OS was 21.22 months vs. 33.75 months, respectively. Perioperative plasma SAA2 levels show a dynamic change pattern related to surgical stress, postoperative recovery, and tumor burden. Postoperative SAA2 measured at one month after surgery may serve as a potential prognostic biomarker in NSCLC patients with uncomplicated recovery, warranting further validation in prospective studies.