Postablation fever after microwave ablation for hepatocellular carcinoma: prognostic implications and the role of periprocedural nursing care

Ultrasound-guided microwave ablation (MWA) is widely accepted as a first-line treatment for selected patients with early-stage hepatocellular carcinoma (HCC), offering minimally invasive management with oncologic outcomes comparable to surgical resection. As the use of ablative therapies expands, increasing attention has been directed toward periprocedural physiological responses and their potential prognostic implications. Among these, postablation fever is one of the most common postoperative events, yet its clinical meaning remains controversial. In this context, we read with great interest the multicenter real-world study by Cai et al[1], which systematically evaluated the association between post-MWA fever and recurrence as well as survival outcomes in patients with HCC. By analyzing the postoperative peak temperature and fever duration, the authors identified a U-shaped relationship between peak temperature and the risks of very early and early recurrence. Notably, transient low-grade fever was associated with a reduced recurrence risk, suggesting that certain postoperative temperature responses may reflect favorable host reactions rather than adverse events. A major strength of this study is its focus on postoperative body temperature, a simple and routinely monitored variable that is deeply embedded in periprocedural nursing care. Traditionally, postablation fever has been regarded primarily as a warning sign of complications, such as infection, often prompting additional diagnostic tests or empirical treatment. In contrast, Cai et al examined both the magnitude and duration of temperature elevation as potential prognostic indicators. Restricted cubic spline analyses demonstrated a nonlinear association between temperature and recurrence risk, indicating that moderate, transient temperature elevation may be associated with improved oncologic outcomes. This observation challenges the conventional assumption that postoperative fever is uniformly undesirable. The authors further defined a phenotype of “transient low-grade fever” and demonstrated its consistent association with lower risks of very early and early recurrence across multivariable and weighting analyses. After excluding patients with overt complications, this fever phenotype appeared to represent a benign postoperative response rather than an event requiring aggressive intervention. The modest but consistent improvements observed in disease-free and overall survival further support its potential relevance at the population level. Methodologically, the study benefits from its multicenter design, extended enrollment period, standardized outcome definitions, and the use of multiple analytical approaches, including spline modeling, multivariable adjustment, and sensitivity analyses. Exploratory analyses of periprocedural lymphocyte counts and neutrophil-to-lymphocyte ratios provided preliminary insight into potential immune-related mechanisms underlying postoperative fever. Nevertheless, postoperative temperature is inherently influenced by peri-procedural nursing surveillance and management. The method of temperature measurement, monitoring frequency, and completeness of documentation directly affect the identification of peak temperature and fever duration. Routine nursing interventions – such as physical cooling, administration of antipyretics, fluid infusion, and use of analgesics or sedatives – may substantially modify observed temperature trajectories. In real-world multicenter settings, variability in nursing protocols and intervention thresholds may therefore influence fever phenotyping. Consequently, postablation fever reflects not only physiological responses but also differences in periprocedural care pathways. Several limitations warrant consideration. Fever phenotyping relied on routine inpatient axillary temperature recordings, which are susceptible to measurement timing and nursing practices. Patients with fever are often monitored more frequently, potentially biasing estimates of fever duration. Inter-center heterogeneity in monitoring intensity and management strategies may further limit reproducibility. In addition, temperature cutoffs were partly data-driven, and the long inclusion period may introduce confounding related to evolving ablation techniques and peri-procedural care standards. From a biological perspective, HCC recurrence is primarily driven by intrinsic tumor aggressiveness. Pathological risk factors such as microvascular invasion are unavailable in ablation-treated patients, and adjustment using tumor burden and AFP levels cannot fully substitute for histopathological stratification. Therefore, transient low-grade fever should be interpreted as a prognostic marker rather than a causal determinant. In summary, this multicenter real-world study suggests that postoperative temperature trajectories following MWA may contain clinically meaningful prognostic information. Future prospective studies with standardized temperature monitoring, nursing interventions, and documentation practices are needed to clarify the role of postablation fever in postoperative risk stratification. Until these issues are addressed, the findings should be regarded as hypothesis-generating rather than directly prescriptive for clinical management[2].