Age-related Survival Outcomes for Pancreatic Cancer by Age

Single-cell analysis reveals the disparities in immune profiles between younger and elder patients

PURPOSE

The immune profiles of elder patients with non-small cell lung cancer (NSCLC) differ significantly from those of younger patients. The tumor microenvironment (TME) is a crucial factor in cancer progression and therapeutic responses. The present study aims to decipher the difference in TME between younger and elderly patients with lung cancers.

METHODS

We downloaded single-cell RNA data from public databases. The algorithm of uniform manifold approximation and projection (UMAP) was applied to cluster and visualize single-cell sequencing data. Gene set variation analysis (GSVA) and gene set enrichment analysis (GSEA) analysis were performed to evaluate the physiological functional characteristics in sub-group cells. CellPhoneDB was used to identify cell-cell interactions between immune cells within TME.

RESULTS

We conducted single-cell RNA sequencing on 96,491 cells from elderly patients and 169,207 cells from younger patients, respectively. We observed that epithelial cells were the predominant component of the TME in younger patients, whereas T/NK cells were the predominant cell type in the TME of elderly patients. We also found that there was a higher proportion of Tregs and a lower proportion of NK, effector CD8+T and γδT cells in elder patients compared with younger patients. In addition, a comparative GSEA analysis of NK cells between older and younger patients revealed that the pathways of Parkinson's disease, Alzheimer's disease, mismatch repair, and base excision repair were up-regulated in NK cells from elderly patients, while the pathways related to natural killer cell-mediated cytotoxicity and allograft rejection were downregulated. Furthermore, we identified tumor-associated neutrophils (TANs) in elder patients, and GSVA analysis demonstrated that the pathway of angiogenesis was upregulated, and the pathway of interferon_γ_response, inflammatory_response, TNFα_signaling_via_NFκB pathways were downregulated. Importantly, the pro-inflammatory response scores of complement C1q C chain positive (C1QC+) macrophages, tissue-resident macrophages (TRM), non-classical monocytes (NCM), secreted phosphoprotein 1 positive (SPP1+) macrophages, and classical monocytes (CM) in elder patients were significantly lower compared to those in younger patients. Finally, cell-to-cell communication analyses unveiled the disparities in regulatory patterns between elder and younger patients, namely the pairs of CXCL13-ACKR4 and CSF1-SIRPA in elder patients and the pairs of CTLA4-CD86 and TIGIT-NECTIN2 in younger patients.

CONCLUSION

This study reveals the distinct immune profiles between younger and elder NSCLC patients, and the elder patients were likely to exhibit a more immunosuppressive TME and attenuated tumor-killing capability compared with younger patients.

Perineural invasion score system and clinical outcomes in resected pancreatic cancer patients

BACKGROUND/OBJECTIVES

Perineural invasion (PNI), classified according to its presence or absence in tumor specimens, is recognized as a poor prognostic factor in pancreatic ductal adenocarcinoma (PDAC) patients. Herein, we identified five histological features of PNI and investigated their impact on survival outcomes of PDAC resected patients.

METHODS

Five histopathological features of PNI (diameter, number, site, sheath involvement, and mitotic figures within perineural invasion) were combined in an additional final score (ranging from 0 to 8), and clinical data of PDAC patients were retrospectively analyzed. PNI + patients were stratified in two categories according to the median score value (<6 and ≥ 6, respectively). Impact of PNI on disease-free survival (DFS) and overall survival (OS) were analyzed.

RESULTS

Forty-five patients were enrolled, of whom 34 with PNI (PNI+) and 11 without PNI (PNI-). The DFS was 11 months vs. not reached (NR) (p = 0.258), while the OS was 19 months vs. NR (p = 0.040) in PNI+ and PNI- patients, respectively. A ≥6 PNI was identified as an independent predictor of worse OS vs. <6 PNI + patients (29 vs. 11 months, p < 0.001) and <6 PNI+ and PNI- patients (43 vs. 11 months, p < 0.001). PNI ≥6 was an independent negative prognostic factor of DFS vs. <6 PNI+ and PNI- patients (13 vs. 6 months, p = 0.022).

CONCLUSIONS

We report a PNI scoring system that stratifies surgically-treated PDAC patients in a graded manner that correlates with patient prognosis better than the current dichotomous (presence/absence) definition. However, further and larger studies are needed to support this PNI scoring system.

Disparities in time to treatment initiation for rectal cancer patients: an analysis of demographic and socioeconomic factors

Background

This study investigated demographic and socioeconomic factors contributing to disparities in the time to treatment for rectal cancer. Subgroup analysis based on age < 50 and ≥ 50 was performed to identify differences in time to treatment among young adults (age < 50) compared to older adults with rectal cancer.

Methods

An analysis was performed using data from the National Cancer Database, spanning from 2004 to 2019. The study encompassed 281,849 patients diagnosed with rectal cancer. We compared time intervals from diagnosis to surgery, radiation, and chemotherapy, considering age, sex, race, and socioeconomic variables. Analyses were performed for the entire cohort and for two subgroups based on age (< 50 and ≥ 50).

Results

Overall, Hispanic patients experienced longer times to surgery, radiation, and chemotherapy compared to non-Hispanic patients (surgery: 94.2 vs. 79.1 days, radiation: 65.0 vs. 55.6 days, chemotherapy: 56.4 vs. 47.8 days, all p < 0.001). Patients with private insurance had shorter times to any treatment (32.5 days) compared to those with government insurance or no insurance (30.6 and 32.5 days, respectively, p < 0.001). Black patients experienced longer wait times for both radiation (63.4 days) and chemotherapy (55.2 days) compared to White patients (54.9 days for radiation and 47.3 days for chemotherapy, both p < 0.001). Interestingly, patients treated at academic facilities had longer times to treatment in surgery, radiation, and chemotherapy compared to those treated at comprehensive and community facilities. When analyzed by age, many of the overall differences persisted despite the age stratification, suggesting that these disparities were driven more by demographic and socioeconomic variables rather than by age.

Conclusion

Significant differences in the time to treatment for rectal cancer have been identified. Hispanic patients, individuals lacking private insurance, Black patients, and patients receiving care at academic facilities had the longest times to treatment. However, these differences were largely unaffected by the age (< 50 and ≥ 50) subgroup analysis. Further investigation into the causes of these disparities is warranted to develop effective strategies for reducing treatment gaps and enhancing overall care for rectal cancer patients.

Identification of age- and immune-related gene signatures for clinical outcome prediction in lung adenocarcinoma

BACKGROUND

The understanding of the factors causing decreased overall survival (OS) in older patients compared to younger patients in lung adenocarcinoma (LUAD) remains.

METHODS

Gene expression profiles of LUAD were obtained from publicly available databases by Kaplan-Meier analysis was performed to determine whether age was associated with patient OS. The immune cell composition in the tumor microenvironment (TME) was evaluated using CIBERSORT. The fraction of stromal and immune cells in tumor samples were also using assessed using multiple tools including ESTIMATE, EPIC, and TIMER. Differentially expressed genes (DEGs) from the RNA-Seq data that were associated with age and immune cell composition were identified using the R package DEGseq. A 22-gene signature composed of DEGs associated with age and immune cell composition that predicted OS were constructed using Least Absolute Shrinkage and Selection Operator (LASSO).

RESULTS

In The Cancer Genome Atlas (TCGA)-LUAD dataset, we found that younger patients (≤70) had a significant better OS compared to older patients (>70). In addition, older patients had significantly higher expression of immune checkpoint proteins including inhibitory T cell receptors and their ligands. Moreover, analyses using multiple bioinformatics tools showed increased immune infiltration, including CD4+ T cells, in older patients compared to younger patients. We identified a panel of genes differentially expressed between patients >70 years compared to those ≤70 years, as well as between patients with high or low immune scores and selected 84 common genes to construct a prognostic gene signature. A risk score calculated based on 22 genes selected by LASSO predicted 1, 3, and 5-year OS, with an area under the curve (AUC) of 0.72, 0.72, 0.69, receptively, in TCGA-LUAD dataset and an independent validation dataset available from the European Genome-phenome Archive (EGA).

CONCLUSION

Our results demonstrate that age contributes to OS of LUAD patients atleast in part through its association with immune infiltration in the TME.