Beyond mismatch repair deficiency? Pre-treatment neutrophil-to-lymphocyte ratio is associated with improved overall survival in patients with recurrent endometrial cancer treated with immunotherapy

Pretreatment systemic inflammatory markers predict survival in endometrial cancer: A Japanese Gynecologic Oncology Group 2043 exploratory data analysis

OBJECTIVE

We investigated whether pretreatment systemic inflammatory markers are associated with survival outcomes in patients with endometrial cancer (EC).

METHODS

Data from the Japanese Gynecologic Oncology Group 2043 were analyzed. Patients who did not receive chemotherapy or were lost to follow-up were excluded. Associations of pretreatment systemic inflammatory markers, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and hemoglobin, albumin, lymphocyte, and platelet (HALP) score, with progression-free survival (PFS) and overall survival (OS) were analyzed. The optimal NLR, PLR, and HALP score cutoff values for PFS and OS were determined. Survival estimates were calculated and compared using the Kaplan-Meier method and log-rank test.

RESULTS

We included 712 patients (median age: 55 [range, 28-74] years; body mass index [BMI]: 21.1 [15.2-38.6] kg/m2). For PFS, optimal NLR, PLR, and HALP score cutoff values were 1.48, 0.017, and 35.52, respectively, and for OS, the values were 1.88, 0.026, and 19.87, respectively. At optimal PFS-related cutoff values, NLR was associated with BMI; PLR with age, BMI, and clinical stage; and HALP score with BMI, clinical stage, and lymph node metastasis. At optimal OS-related cutoff values, NLR was associated with BMI, PLR, and BMI; the HALP score was associated with age and BMI. The HALP score was a prognostic factor for PFS (p = 0.025), while PLR and HALP scores were prognostic factors for OS (both p = 0.028).

CONCLUSIONS

Pretreatment systemic inflammatory markers are associated with survival outcomes in patients with EC, with the HALP score being a prognostic factor for PFS and OS.

Reanalysis of single-cell data reveals macrophage subsets associated with the immunotherapy response and prognosis of patients with endometrial cancer

Endometrial cancer (EC) is an aggressive gynecological malignancy with an increased incidence rate. The immune landscape crucially affects immunotherapy efficacy and prognosis in EC patients. Here, we characterized the distinct tumor microenvironment signatures of EC tumors by analyzing single-cell RNA sequencing data from Gene Expression Omnibus and bulk RNA sequencing data from The Cancer Genome Atlas, which were compared with normal endometrium. Three macrophage subsets were identified, and two of them showed tissue-specific distribution. One of the macrophage subsets was dominant in macrophages derived from EC and exhibited characteristic behaviors such as promoting tumor growth and metastasis. One of the other macrophage subsets was mainly found in normal endometrium and served functions related to antigen presentation. We also identified a macrophage subset that was found in both EC and normal endometrial tissue. However, the pathway and cellular cross-talk of this subset were completely different based on the respective origin, suggesting a tumor-related differentiation mechanism of macrophages. Additionally, the tumor-enriched macrophage subset was found to predict immunotherapy responses in EC. Notably, we selected six genes from macrophage subset markers that could predict the survival of EC patients, SCL8A1, TXN, ANXA5, CST3, CD74 and NANS, and constructed a prognostic signature. To verify the signature, we identified immunohistochemistry for the tumor samples of 83 EC patients based on the selected genes and further followed up with the survival of the patients. Our results provide strong evidence that the signature can effectively predict the prognosis of EC patients.

Immune escape and resistance to immunotherapy in mismatch repair deficient tumors

Up to 30% of colorectal, endometrial and gastric cancers have a deficiency in mismatch repair (MMR) protein expression due to either germline or epigenetic inactivation. Patients with Lynch Syndrome who inherit an inactive MMR allele have an up to 80% risk for developing a mismatch repair deficient (MMRd) cancer. Due to an inability to repair DNA, MMRd tumors present with genomic instability in microsatellite regions (MS). Tumors with high MS instability (MSI-H) are characterized by an increased frequency of insertion/deletions (indels) that can encode novel neoantigens if they occur in coding regions. The high tumor antigen burden for MMRd cancers is accompanied by an inflamed tumor microenvironment (TME) that contributes to the clinical effectiveness of anti-PD-1 therapy in this patient population. However, between 40 and 70% of MMRd cancer patients do not respond to treatment with PD-1 blockade, suggesting that tumor-intrinsic and -extrinsic resistance mechanisms may affect the success of checkpoint blockade. Immune evasion mechanisms that occur during early tumorigenesis and persist through cancer development may provide a window into resistance pathways that limit the effectiveness of anti-PD-1 therapy. Here, we review the mechanisms of immune escape in MMRd tumors during development and checkpoint blockade treatment, including T cell dysregulation and myeloid cell-mediated immunosuppression in the TME. Finally, we discuss the development of new therapeutic approaches to tackle resistance in MMRd tumors, including cancer vaccines, therapies targeting immunosuppressive myeloid programs, and immune checkpoint combination strategies.