The study included 126 patients with muscle-invasive bladder cancer who underwent radical cystectomy with a Bricker ileal conduit, a urinary diversion technique in which a segment of intestine is used to create a stoma. Sixty-three patients were managed with a 22-element ERAS protocol adapted from ERAS Society guidelines, while 63 historical controls received standard perioperative care. The ERAS pathway combined eight preoperative elements, including patient education, nutritional optimization, carbohydrate loading, and shortened fasting, with seven intraoperative measures such as epidural analgesia, goal-directed fluid therapy, and active maintenance of body temperature, and seven postoperative elements including early feeding, early mobilization, and milestone-based discharge criteria. Many of these components were delivered or coordinated by nursing staff, making the protocol as much a nursing intervention as a surgical one.

To track immune changes, the team drew blood at three standardized timepoints: 24 hours before surgery, 24 hours after surgery, and on postoperative day seven or at discharge. Multiplex flow cytometry quantified cytotoxic CD8-positive T cells, regulatory T cells, and natural killer cells, while a 37-analyte Luminex panel measured inflammatory cytokines and ELISA assays captured soluble immune checkpoint molecules such as soluble PD-L1. The differences between the two groups were striking. In the ERAS cohort, CD8-positive T-cell counts fell by 22.8 percent from baseline in the first 24 hours after surgery, compared with a 41.6 percent decline in the conventional group, a difference that was highly statistically significant. Serum interleukin-6, a key inflammatory cytokine released during surgical stress, averaged 43.2 picograms per milliliter in ERAS patients versus 87.4 picograms per milliliter in conventional patients.

Beyond the cellular counts, the soluble immune landscape also differed. ERAS patients showed lower concentrations of soluble PD-L1 and soluble TIM-3, molecules shed into the bloodstream that are thought to dampen antitumor immunity, and higher levels of interferon-gamma, a cytokine central to cytotoxic immune defense. Natural killer cell activity was also better preserved, at 42.3 percent versus 31.7 percent. By postoperative day seven, several of these measures remained more favorable in the ERAS group, including higher CD8 counts and lower proportions of immunosuppressive regulatory T cells. The authors are careful to note, however, that these timepoint comparisons alone cannot establish a causal effect of ERAS on immune trajectories, since no formal group-by-time mixed-effects analysis was performed.

One of the most intriguing findings is an exploratory four-marker immune index measured 24 hours after surgery, combining CD8-positive T-cell count, interleukin-6, soluble PD-L1, and natural killer cell activity. When the researchers tested this composite score against the risk of infectious complications within 30 days of surgery, it achieved an area under the receiver operating characteristic curve of 0.84, with a 95 percent confidence interval of 0.76 to 0.92. That performance substantially exceeded a reference model based only on ASA score and clinical stage, which reached an AUC of 0.61. Individual markers performed less well, with interleukin-6 alone at 0.76 and CD8 count alone at 0.73, suggesting that the integration of multiple immune dimensions carries the predictive signal.

The team also examined the tumors themselves. Using multiplex immunofluorescence on surgical specimens, they quantified immune cell infiltration in tumor nests, invasive margins, and surrounding stroma. Specimens from the ERAS cohort showed higher densities of CD8-positive tumor-infiltrating lymphocytes in both tumor nests and invasive margins, lower densities of CD68-positive CD163-positive M2-polarized macrophages, and higher ratios of CD8-positive to FoxP3-positive cells, a measure that weighs cytotoxic against regulatory immune activity. Spatial transcriptomics performed on 24 specimens revealed higher expression of cytotoxic effector genes such as GZMB, PRF1, and IFNG, and lower expression of exhaustion markers including TIGIT, LAG3, and PDCD1 in the ERAS group. The immune-inflamed tumor phenotype, characterized by T cells penetrating deep into tumor tissue, was present in 52.4 percent of ERAS specimens versus 28.6 percent of conventional ones.

Here the authors issue an important caution. Because tumor tissue was collected at the time of cystectomy, before any postoperative ERAS component such as early feeding or mobilization could have taken effect, the tumor immune differences are cross-sectional observations rather than evidence that ERAS remodels the tumor microenvironment. They may reflect pre-existing tumor biology, differences in surgical approach, calendar-period effects, or other confounders. Indeed, the ERAS group had shorter operative times, less blood loss, lower transfusion rates, and more frequent minimally invasive surgery, all of which could independently influence both systemic immunity and tumor immune features.

Clinically, the ERAS group fared better on nearly every recovery measure. Time to first flatus was 2.1 days versus 3.4 days, first oral intake occurred at 8.2 hours versus 28.7 hours, and first mobilization at 12.4 hours versus 24.6 hours. Postoperative length of stay averaged 4.8 days compared with 7.2 days, resting pain scores on the first day after surgery were 3.2 versus 5.1 on a ten-point scale, and total hospitalization costs were 22.4 percent lower. The overall rate of 30-day infectious complications was numerically lower in the ERAS group at 19.0 percent versus 33.3 percent, but this difference did not reach conventional statistical significance after recalculation, with a P value of 0.068.

Survival analyses, while exploratory, added another layer. Among patients with available follow-up, descriptive three-year overall survival proportions were 78.1 percent in the ERAS cohort and 68.3 percent in the conventional cohort, though the authors stress these are not formal Kaplan-Meier estimates for the full cohort. In multivariable Cox models, ERAS management was associated with an overall survival hazard ratio of 0.58, and an eight-gene immune signature comprising cytotoxic effectors, exhaustion markers, FOXP3, CD163, and IL6 showed an even stronger association at a hazard ratio of 0.47. Notably, the survival benefit associated with ERAS appeared concentrated in patients whose tumors had high tumor mutational burden, with a hazard ratio of 0.41 in that subgroup and a nominal interaction P value of 0.048.

The authors are unequivocal that these biomarker and survival findings are hypothesis-generating rather than validated. The four-marker index and eight-gene signature were developed and tested in the same retrospective cohort, creating a real risk of overfitting, and only 33 infectious events were available for the predictive analysis. The single-center historical-control design means ERAS exposure is tightly correlated with calendar period, and secular improvements in surgical technique, infection control, and systemic therapy could account for some of the observed differences. Mean follow-up was approximately 24 months, limiting interpretation of three-year outcomes. What the study does establish is a detailed immunological portrait of what happens to the immune system after major cancer surgery under two different care philosophies, and a roadmap for the prospective, contemporaneous trials with longitudinal immune sampling and paired tumor biopsies that will be needed before any of these signals can guide clinical practice.

Subject of Research: Perioperative immunogenomic differences between ERAS-based and conventional nursing care in muscle-invasive bladder cancer patients undergoing radical cystectomy

Article Title: Perioperative immunogenomics and clinical outcomes under ERAS-based nursing care in muscle-invasive bladder cancer

Article References: Xin, L.-L., Guo, J.-J., Zheng, X.-Y., & Li, Z.-Y. (2026). Perioperative immunogenomics and clinical outcomes under ERAS-based nursing care in muscle-invasive bladder cancer. Frontiers in Genetics, 17, Article 1967034. https://doi.org/10.3389/fgene.2026.1967034

Image Credits: AI Generated

DOI: 10.3389/fgene.2026.1967034

Keywords: bladder cancer, ERAS, radical cystectomy, perioperative immunogenomics, CD8 T cells, tumor immune microenvironment, immune biomarkers, interleukin-6, tumor mutational burden, spatial transcriptomics, nursing care, infectious complications