Levels of Inflammatory and Oncological Biomarkers Pre- and Postoperatively
BMI and inflammatory biomarkers (IL-6, CRP) as well as the oncological marker (CEA) were evaluated at two time points: baseline (Week 0, preoperative) and final (Week 8, approximately 1 month postoperative). The results of intra-group and inter-group comparisons are presented in Table 2.
1. Body Mass Index (BMI)
Baseline BMI was comparable between the Del-Immune V® group and the Control group [24.6 kg/m² (IQR: 22.6–27.7) vs. 25.8 kg/m² (IQR: 20.8–28.7), p = 0.867]. At the end of follow-up (Week 8), no significant differences were observed between groups [23.7 kg/m² (IQR: 22.4–26.5) vs. 23.9 kg/m² (IQR: 19.8–26.2), p = 0.923]. The absolute change in BMI (Δ = Final – Baseline) was similar between the Del-Immune V® group [-0.5 kg/m² (IQR: -1.8–0.3)] and the Control group [-0.4 kg/m² (IQR: -1.5–0.6)], with no statistically significant differences (p = 0.789). Intra-group comparisons showed no significant changes from baseline to Week 8 in either group (Del-Immune V®: p = 0.234; Control: p > 0.05). These findings indicate that Del-Immune V® treatment had no significant effect on nutritional status measured by BMI in the early postoperative period.
2. Interleukin-6 (IL-6)
At the end of follow-up (Week 8), the Del-Immune V® group presented lower IL-6 levels [4.23 pg/mL (IQR: 2.34–8.59)] compared to the Control group [6.23 pg/mL (IQR: 3.22–12.35)], although the difference did not reach statistical significance (p = 0.189). Intra-group analysis showed a significant reduction in IL-6 from baseline to Week 8 in the Del-Immune V® group (p = 0.012), while the Control group showed no significant change (p = 0.570). The magnitude of absolute change (Δ) was greater in the Del-Immune V® group [-3.52 pg/mL (IQR: -8.24–0.45)] versus the Control group [-2.15 pg/mL (IQR: -6.89–1.23)], without significant differences between groups (p = 0.634). These results suggest that Del-Immune V® treatment is associated with a significant reduction in IL-6 levels in the postoperative period, which may reflect modulation of the systemic inflammatory response mediated by the metabolite.
3. C-Reactive Protein (CRP)
At the end of follow-up (Week 8), both groups showed a marked reduction in CRP levels, with no significant differences between them [3.26 mg/L (IQR: 2.06–6.28) vs. 3.46 mg/L (IQR: 2.27–8.64), p = 0.657]. Intra-group analysis demonstrated a highly significant reduction in CRP from baseline to Week 8 in both groups (Del-Immune V®: p < 0.001; Control: p = 0.001). The magnitude of absolute change (Δ) was greater in the Del-Immune V® group [-8.54 mg/L (IQR: -25.3–(-2.1))] versus the Control group [-5.89 mg/L (IQR: -18.7–(-1.5))], without significant differences between groups (p = 0.423). These findings indicate that resective surgery itself induces a significant reduction in CRP in the postoperative period, reflecting resolution of the tumor-associated inflammatory process. The trend toward greater reduction in the Del-Immune V® group may suggest an additive effect of the metabolite on normalization of this inflammatory marker.
4. Carcinoembryonic Antigen (CEA)
At the end of follow-up (Week 8), both groups showed a reduction in CEA levels, with no significant differences between them [2.95 ng/mL (IQR: 1.65–5.42) vs. 2.49 ng/mL (IQR: 1.29–3.42), p = 0.312]. Intra-group analysis showed a trend toward reduction of CEA in the Del-Immune V® group (p = 0.076), while the Control group showed no significant change (p = 0.155). The magnitude of absolute change (Δ) was similar between groups [-1.23 ng/mL (IQR: -4.56–0.34) vs. -0.89 ng/mL (IQR: -3.21–0.67), p = 0.567]. These results suggest that surgical resection of the tumor is associated with a reduction in CEA levels in the early postoperative period, as expected. The trend toward greater reduction in the Del-Immune V® group may indicate a beneficial effect of the metabolite on residual tumor burden or associated inflammation.
These findings support the hypothesis that Del-Immune V® may modulate the perioperative inflammatory response in patients undergoing resective surgery for colorectal cancer, particularly through the reduction of IL-6, a key marker of systemic inflammation and prognosis in this population.
3. Magnitude of Percentage Change in Biomarkers
The magnitude of change in inflammatory and oncological biomarkers was evaluated by calculating the percentage change (Δ%) between baseline values (Week 0) and final values (Week 8). Additionally, the proportion of patients who achieved normalization of each biomarker (values within the reference range at the end of follow-up) was analyzed. Results are presented in Table 3.
1. Percentage Change in Interleukin-6 (IL-6)
The percentage change in IL-6 levels showed a greater reduction in the Del-Immune V® group [-45.2% (IQR: -68.5 to -12.3)] compared to the Control group [-28.7% (IQR: -55.4 to 8.9)], without reaching statistical significance (p = 0.234). These results indicate that although both groups experienced a decrease in IL-6 levels during the postoperative period, the magnitude of reduction was approximately 1.6 times greater in the group receiving the metabolite. It is noteworthy that the interquartile range of the control group included positive values (up to 8.9%), suggesting that some patients in this group experienced an increase in IL-6 levels rather than a reduction.
2. Percentage Change in C-Reactive Protein (CRP)
The percentage change in CRP showed a more pronounced reduction in the Del-Immune V® group [-62.8% (IQR: -85.2 to -35.6)] versus the Control group [-48.3% (IQR: -72.1 to -18.9)], with a difference that did not reach statistical significance (p = 0.189). The magnitude of CRP reduction exceeded 60% in the intervention group, reflecting faster normalization of this acute inflammatory marker. As with IL-6, the interquartile range of the control group showed greater variability, with some patients presenting less marked reductions.
3. Percentage Change in Carcinoembryonic Antigen (CEA)
The percentage change in CEA was similar between the Del-Immune V® group [-32.5% (IQR: -58.9 to 12.4)] and the Control group [-25.6% (IQR: -48.7 to 18.3)], with no statistically significant differences (p = 0.445). Both groups showed moderate reductions in CEA levels, consistent with surgical resection of the primary tumor. It is notable that the interquartile ranges of both groups included positive values, indicating that a subset of patients experienced an increase in CEA levels during follow-up, which may reflect residual or progressive disease.
4. Normalization Rates of Biomarkers
IL-6: Normalization (<5 pg/mL at Week 8) was observed in 14 of 22 patients (63.6%) in the Del-Immune V® group versus 8 of 17 patients (47.1%) in the Control group, without significant differences (p = 0.298). Although not statistically significant, the normalization rate was 1.36 times higher in the intervention group.
CRP: Normalization (<5 mg/L at Week 8) was achieved in 18 of 22 patients (81.8%) in the Del-Immune V® group versus 12 of 17 patients (70.6%) in the Control group (p = 0.489). This biomarker showed the highest normalization rates in both groups, consistent with its role as an acute inflammatory marker that tends to normalize after surgical resolution.
CEA: Normalization (<4.7 ng/mL at Week 8) was observed in 15 of 22 patients (68.2%) in the Del-Immune V® group versus 11 of 17 patients (64.7%) in the Control group (p = 0.812). Rates were similar between groups, reflecting that this oncological marker responds primarily to tumor resection rather than metabolite treatment.
These findings are consistent with the hypothesis that Del-Immune V® may modulate the perioperative inflammatory response, although larger studies are required to confirm these effects with greater statistical precision.
4. Perioperative Clinical Outcomes
Perioperative clinical outcomes were evaluated by recording complications, reinterventions, mortality, length of hospital stay, recovery of intestinal transit, readmissions, and disease status at follow-up. Results are presented in Table 4.
1. Total Complications
Total complications occurred in 5 of 22 patients (22.7%) in the Del-Immune V® group versus 1 of 17 patients (5.9%) in the Control group, with no statistically significant differences (p = 0.206). Although the complication rate was approximately 3.9 times higher in the intervention group, the low number of events limits the ability to detect significant differences. Infectious complications occurred in 3 patients (13.6%) in the Del-Immune V® group versus 1 patient (5.9%) in the Control group (p = 0.634). Surgical complications (dehiscence, fistula, hemorrhage) occurred in 2 patients (9.1%) in the intervention group versus none in the control group (p = 0.487).
2. Reintervention and Mortality
The reintervention rate was 4 patients (18.2%) in the Del-Immune V® group versus 0 patients (0%) in the Control group, with a trend toward statistical significance (p = 0.056). Most reinterventions in the Del-Immune V® group corresponded to Stage IV patients requiring additional management of metastatic disease or complications related to advanced disease. Thirty-day mortality was 1 patient (4.5%) in the Del-Immune V® group versus 0 patients (0%) in the Control group (p = 1.000). Six-month mortality was 2 patients (9.1%) in the intervention group versus 0 patients (0%) in the Control group (p = 0.487). Causes of death were related to progression of metastatic disease in both cases.
3. Postoperative Recovery
Length of hospital stay was longer in the Del-Immune V® group [5.0 days (IQR: 3.0–7.0)] compared to the Control group [3.0 days (IQR: 3.0–5.0)], with a trend toward statistical significance (p = 0.070). This difference may be partially explained by the higher proportion of Stage IV patients in the intervention group, who required longer hospitalizations for advanced disease management. Recovery of intestinal transit, measured as time to first bowel movement, was 3.0 days (IQR: 2.0–4.0) in the Del-Immune V® group versus 2.0 days (IQR: 2.0–3.0) in the Control group (p = 0.123). Although not statistically significant, a trend toward slower recovery was observed in the intervention group.
4. Readmission and Follow-up
Thirty-day readmissions occurred in 2 patients (9.1%) in the Del-Immune V® group versus 1 patient (5.9%) in the Control group (p = 1.000). Ninety-day readmissions were 3 patients (13.6%) versus 1 patient (5.9%), respectively (p = 0.634). None of these differences reached statistical significance. Completion of adjuvant chemotherapy was similar between groups: 12 of 15 patients (80.0%) in the Del-Immune V® group versus 11 of 13 patients (84.6%) in the Control group completed the proposed regimen (p = 1.000). This suggests that metabolite treatment did not negatively affect tolerance to adjuvant chemotherapy.
5. Disease Status at Follow-up (February 2026)
At the time of the last follow-up (February 2026), disease was controlled in 14 patients (63.6%) in the Del-Immune V® group versus 13 patients (76.5%) in the Control group (p = 0.389). Disease progression occurred in 4 patients (18.2%) in the intervention group versus 1 patient (5.9%) in the Control group (p = 0.356). Recurrences were observed in 2 patients (9.1%) in the Del-Immune V® group versus 2 patients (11.8%) in the Control group (p = 1.000), with no significant differences between groups. Deaths at follow-up were 2 patients (9.1%) in the intervention group versus 0 patients (0%) in the Control group (p = 0.487).
Conclusion: These findings must be interpreted considering the important limitation of tumor stage imbalance between groups, with a higher proportion of Stage IV patients in the Del-Immune V® group (22.7% vs. 0%, p = 0.056), which represents a confounding factor that may have attenuated the potential beneficial effects of the metabolite.
5. Correlation Between Biomarkers and Clinical Outcomes
The association between inflammatory biomarkers (IL-6, CRP) and the oncological biomarker (CEA), measured at Week 8 postoperatively, as well as their changes from baseline (Δ), was evaluated in relation to various relevant clinical outcomes. Spearman correlation coefficients and their statistical significance values are presented in Table 5.
1. Length of Hospital Stay
Length of hospital stay did not show statistically significant correlations with any of the biomarkers evaluated at Week 8. However, a trend toward a moderate positive correlation was observed with CRP at Week 8 (r = 0.289, p = 0.074), suggesting that patients with higher CRP levels at the end of follow-up may require longer hospital stays. IL-6 at Week 8 showed a weak positive correlation (r = 0.234, p = 0.152), while CEA at Week 8 presented the lowest correlation (r = 0.156, p = 0.345). Changes in biomarkers from baseline (Δ IL-6, Δ CRP, Δ CEA) were not significantly associated with hospital stay (all p > 0.05).
2. Postoperative Complications
The presence of postoperative complications (Yes/No) showed a trend toward positive correlation with IL-6 levels at Week 8 (r = 0.312, p = 0.054), indicating that patients with higher levels of this inflammatory marker at the end of follow-up may have a greater likelihood of experiencing complications. CRP at Week 8 also showed a moderate positive correlation, though not significant (r = 0.278, p = 0.087). CEA at Week 8 presented a weaker correlation (r = 0.189, p = 0.248). Changes in biomarkers from baseline showed moderate negative correlations with complications (Δ IL-6: r = -0.267, p = 0.099; Δ CRP: r = -0.245, p = 0.134), suggesting that patients with greater reductions in inflammatory markers may have lower risk of complications, although these associations did not reach statistical significance.
3. Surgical Reintervention
The need for surgical reintervention did not show significant correlations with any biomarker evaluated. A trend toward positive correlation was observed with IL-6 at Week 8 (r = 0.289, p = 0.075), consistent with the finding of a higher reintervention rate in the Del-Immune V® group observed in Table 4, likely related to the higher proportion of advanced-stage patients in this group. Changes in biomarkers (Δ) were not significantly associated with reintervention (all p > 0.05).
4. CEA Levels at Week 8
CEA levels at Week 8 showed trends toward positive correlation with inflammatory markers IL-6 at Week 8 (r = 0.298, p = 0.066) and CRP at Week 8 (r = 0.267, p = 0.101). This suggests that patients with greater systemic inflammation at the end of follow-up may have higher levels of the tumor marker, possibly reflecting residual disease or tumor-associated inflammatory response. Changes in inflammatory biomarkers showed moderate negative correlations with CEA at Week 8 (Δ IL-6: r = -0.245, p = 0.134; Δ CRP: r = -0.223, p = 0.172), indicating that greater reductions in inflammation are associated with lower postoperative CEA levels.