Mechanism underlying the transient increase of serum iron during FOLFOX/FOLFIRI therapy

Serum nutritional predictive biomarkers and risk assessment for anastomotic leakage after laparoscopic surgery in rectal cancer patients

BACKGROUND

Anastomotic leakage (AL) is one of the severest complications after laparoscopic surgery for middle/low rectal cancer, significantly impacting patient outcomes. Identifying reliable predictive factors for AL remains a clinical challenge. Serum nutritional biomarkers have been implicated in surgical outcomes but are underexplored as predictive tools for AL in this setting. Our study hypothesizes that preoperative serum levels of prealbumin (PA), albumin (ALB), and transferrin (TRF), along with surgical factors, can accurately predict AL risk.

AIM

To determine the predictive value of preoperative serum nutritional biomarkers for rectal cancer AL following laparoscopic surgery.

METHODS

In the retrospective cohort study carried out at a tertiary cancer center, we examined 560 individuals who underwent laparoscopic procedures for rectal cancer from 2018 to 2022. Preoperative serum levels of PA, ALB, and TRF were measured. We employed multivariate logistic regression to determine the independent risk factors for AL, and a predictive model was constructed and evaluated using receiver operating characteristic curve analysis.

RESULTS

AL occurred in 11.96% of cases, affecting 67 out of 560 patients. Multivariate analysis identified PA, ALB, and TRF as the independent risk factor, each with an odds ratio of 2.621 [95% confidence interval (CI): 1.582-3.812, P = 0.012], 3.982 (95%CI: 1.927-4.887, P = 0.024), and 2.109 (95%CI: 1.162-2.981, P = 0.031), respectively. Tumor location (< 7 cm from anal verge) and intraoperative bleeding ≥ 300 mL also increased AL risk. The predictive model demonstrated an excellent accuracy, achieving an area under the receiver operating characteristic curve of 0.942, a sensitivity of 0.844, and a specificity of 0.922, demonstrating an excellent ability to discriminate.

CONCLUSION

Preoperative serum nutritional biomarkers, combined with surgical factors, reliably predict anastomotic leakage risk after rectal cancer surgery, highlighting their importance in preoperative assessment.

Impact of low serum iron on treatment outcome of PD-1 inhibitors in advanced gastric cancer

BACKGROUND

The aim of this study was to investigate the influence of serum iron levels in advanced gastric cancer (GC) patients treated with programmed cell death protein-1 (PD-1) inhibitors.

METHODS

We retrospectively reviewed 149 GC patients who were treated with PD-1 inhibitors at our center. Clinicopathological characteristics, laboratory data, and clinical outcomes were analyzed.

RESULTS

Multivariate analysis showed that Eastern Cooperative Oncology Group performance status (ECOG PS), histological subtype, and baseline serum iron levels were independent prognostic factors for overall survival (OS), while ECOG PS, multiple metastatic sites, and baseline serum iron levels were independent prognostic factors for progression-free survival (PFS). Patients with baseline low serum iron levels (LSI) had a significantly shorter median OS and PFS compared to patients with normal serum iron levels (NSI) (Median OS: 7 vs. 14 months, p = 0.001; median PFS: 3 vs. 5 months, p = 0.005). Patients with baseline LSI had a disease control rate (DCR) of 58.3% at 2 months after PD-1 inhibitor initiation (M2), compared to 81.1% in patients with NSI (p = 0.005). Patients with baseline LSI had a DCR of 43.8% at 4 months, compared to 64.2% in patients with NSI (p = 0.017).

CONCLUSIONS

LSI was associated with worse OS, PFS, and DCR in GC patients treated with PD-1 inhibitors and might be a quick and efficient biomarker to predict the efficacy of PD-1 inhibitors.

Iron metabolism in colorectal cancer

Iron, as one of the essential trace elements in the human body, is involved in a wide range of critical biochemical reactions and physiological processes, including the maintenance of the normal cell cycle, mitochondrial function, nucleotide metabolism, and immune response. In this context, iron is naturally associated with cancer occurrence. Cellular iron deficiency can induce apoptosis, however, iron can also engage in potentially harmful reactions that produce free radicals because of its capacity to gain and lose electrons. Studies suggest that dietary iron, particularly heme iron, may be one of the leading causes of colorectal cancer (CRC). Moreover, patients with CRC have abnormal iron absorption, storage, utilization, and exportation. Therefore, iron is crucial for the development and progression of CRC. Elaborating on the alterations in iron metabolism during the onset and advancement of CRC would help to further explain the role and mechanism of iron inside the body. Thus, we reviewed the alterations in numerous iron metabolism-related molecules and their roles in CRC, which may provide new clues between iron metabolism and CRC.