Radiation and Modulation of the Tumor Immune Microenvironment in Non-Small Cell Lung Cancer

Radiotherapy combined with immunotherapy: the dawn of cancer treatment

Radiotherapy (RT) is delivered for purposes of local control, but can also exert systemic effect on remote and non-irradiated tumor deposits, which is called abscopal effect. The view of RT as a simple local treatment has dramatically changed in recent years, and it is now widely accepted that RT can provoke a systemic immune response which gives a strong rationale for the combination of RT and immunotherapy (iRT). Nevertheless, several points remain to be addressed such as the interaction of RT and immune system, the identification of the best schedules for combination with immunotherapy (IO), the expansion of abscopal effect and the mechanism to amplify iRT. To answer these crucial questions, we roundly summarize underlying rationale showing the whole immune landscape in RT and clinical trials to attempt to identify the best schedules of iRT. In consideration of the rarity of abscopal effect, we propose that the occurrence of abscopal effect induced by radiation can be promoted to 100% in view of molecular and genetic level. Furthermore, the “radscopal effect” which refers to using low-dose radiation to reprogram the tumor microenvironment may amplify the occurrence of abscopal effect and overcome the resistance of iRT. Taken together, RT could be regarded as a trigger of systemic antitumor immune response, and with the help of IO can be used as a radical and systemic treatment and be added into current standard regimen of patients with metastatic cancer.

Neoadjuvant Therapy Induces a Potent Immune Response to Sarcoma, Dominated by Myeloid and B Cells

PURPOSE

To characterize changes in the soft-tissue sarcoma (STS) tumor immune microenvironment induced by standard neoadjuvant therapy with the goal of informing neoadjuvant immunotherapy trial design.

EXPERIMENTAL DESIGN

Paired pre- and postneoadjuvant therapy specimens were retrospectively identified for 32 patients with STSs and analyzed by three modalities: multiplexed IHC, NanoString, and RNA sequencing with ImmunoPrism analysis.

RESULTS

All 32 patients, representing a variety of STS histologic subtypes, received neoadjuvant radiotherapy and 21 (66%) received chemotherapy prior to radiotherapy. The most prevalent immune cells in the tumor before neoadjuvant therapy were myeloid cells (45% of all immune cells) and B cells (37%), with T (13%) and natural killer (NK) cells (5%) also present. Neoadjuvant therapy significantly increased the total immune cells infiltrating the tumors across all histologic subtypes for patients receiving neoadjuvant radiotherapy with or without chemotherapy. An increase in the percentage of monocytes and macrophages, particularly M2 macrophages, B cells, and CD4+ T cells was observed postneoadjuvant therapy. Upregulation of genes and cytokines associated with antigen presentation was also observed, and a favorable pathologic response (≥90% necrosis postneoadjuvant therapy) was associated with an increase in monocytic infiltrate. Upregulation of the T-cell checkpoint TIM3 and downregulation of OX40 were observed posttreatment.

CONCLUSIONS

Standard neoadjuvant therapy induces both immunostimulatory and immunosuppressive effects within a complex sarcoma microenvironment dominated by myeloid and B cells. This work informs ongoing efforts to incorporate immune checkpoint inhibitors and novel immunotherapies into the neoadjuvant setting for STSs.

Immunomodulatory effect of splenectomy in lung cancer mouse xenograft models receiving radiation therapy

Purpose: This study aims to investigate the effect of splenectomy on radiation-mediated growth inhibition and immune modulation in lung cancer xenograft models. Materials and Methods: Human non-small cell lung cancer H1299 cells and murine Lewis lung carcinoma LL/2-luc cells were injected into the right hind leg of BALB/c-nude mice and C57BL/6 mice, respectively. Splenectomy or sham operation was performed prior to tumor cell injection or before and after irradiation during tumor growth. Irradiation was delivered with 2–3 fractions of 6 Gy X-ray using a linear accelerator. Flow cytometry analysis was performed for immune cell profiling.Results: Splenectomy prior to tumor injection or at early stage inhibited growth of LL/2-luc tumors but not that of H1299 tumors; however, it did not enhance the antitumor effect of radiation regardless of intervention timing. Flow cytometry analysis showed monocytic myeloid-derived suppressor cells (MDSCs) and activated CD8+ T cells increased after irradiation in the tumors of splenectomized mice, compared to those of sham-operated mice. Administration of anti-PD-1 (programmed death-1) antibodies improved the ability of splenectomy to attenuate the growth of irradiated tumors.Conclusion: Splenectomy has paradoxical effects on radiation-induced tumor growth inhibition, depending on tumor types and intervention timing, but it has an immune-modulating effect when combined with radiation.

The Pan-Cancer Crosstalk Between the EFNA Family and Tumor Microenvironment for Prognosis and Immunotherapy of Gastric Cancer

Background: EFNA1-5 have important physiological functions in regulating tumorigenesis and metastasis. However, correlating EFNA genes in the tumor immune microenvironment (TIME), and the prognosis of patients with gastric cancer remains to be determined. Methods: Using public databases, the expression of EFNA1-5 in pan-cancer and gastric cancer was comprehensively analyzed using UCSC Xena, the Oncomine dataset and UALCAN. We further completed survival analysis by Kaplan-Meier plotter to evaluate the prognosis of the high and low expression groups of the EFNAs gene in patients with gastric cancer. The TIMER tool was used to reveal the correlation between immune cell infiltration and genes of interest. Spearman correlation was used to find an association between the EFNA genes and tumor stem cells, TIME, microsatellite instability (MSI) or tumor mutational burden (TMB). We also used cBioportal, GeneMANIA and STRINGS to explore the types of changes in these genes and the protein interactions. Finally, we described the TIME based on QUANTISEQ algorithm, predicted the relationship between the EFNA genes and half-maximal inhibitory concentration (IC₅₀), and analyzed the relationship between the EFNA family genes and immune checkpoints. Results: The expression of EFNA1, EFNA3, EFNA4, and EFNA5 was elevated in pan-cancer. Compared with normal adjacent tissues, EFNA1, EFNA3, and EFNA4 were up-regulated in gastric cancer. In terms of the influence on the survival of patients, the expression of EFNA3 and EFNA4 were related to overall survival (OS) and disease-free survival (DFS) for patients with gastric cancer. High expression of EFNA5 often predicted poor OS and DFS. In gastric cancer, the expression of EFNA3 and EFNA4 showed a significant negative correlation with B cells. The higher the expression of EFNA5, the higher the abundance of B cells, CD4+T cells and macrophages. CD8+T cells, dendritic cells infiltration and EFNA1-4 expression were negatively correlated. The infiltration of CD4+T cells, macrophages and neutrophils was negatively correlated with the expression of EFNA1, EFNA3, and EFNA4. TMB and MSI were positively correlated with EFNA3/EFNA4 expression. In the tumor microenvironment and drug sensitivity, EFNA3/4/5 also showed a significant correlation. In addition, we explored the relationship between the EFNA family genes and the immune microenvironment (B cells, M2 macrophages, monocytes, CD8⁺ T cells, regulatory T cells, myeloid dendritic cells, natural killer cells, non-regulatory CD4⁺ T cells), immune checkpoint (PDCD1, PDCD1LG2, CD274, CTLA4), and IC₅₀ of common chemotherapeutic drugs for gastric cancer (5-fluorouracil, cisplatin, docetaxel and gemcitabine). Conclusions: Our study provides new ideas for tumor treatment and prognosis from the perspective of TIME, and nominates EFNA1-5 to become potential therapeutic targets for gastric cancer.

The benefits and risks of CTLA4 inhibitor plus PD1/PDL1 inhibitor in stage IIIB/IV non-small cell lung cancer: A systematic analysis and meta-analysis based on randomized controlled trials

WHAT IS KNOWN AND OBJECTIVE

Although immune checkpoint inhibitors (ICIs) have shown clinical benefit for patients with non-small cell lung cancer (NSCLC), the efficacy of the combination of ICIs targeting different pathways is still unclear. We performed this meta-analysis to explore the efficacy of cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor plus programmed cell death 1 receptor (PD-1)/programmed cell death receptor ligand 1 (PD-L1) inhibitor therapy (CP) for NSCLC IIIB/IV patients.

METHODS

We systematically searched the main databases for relevant studies. The main outcomes were overall survival (OS) and progression-free survival (PFS).

RESULTS AND DISCUSSION

We identified 3526 articles, including 5 randomized controlled trials (RCTs) (4377 patients), in our meta-analysis. We conducted two comparisons of CP versus chemotherapy or PD1/PDL1 inhibitor (P). Compared with chemotherapy, CP was more effective, with better OS (hazard ratio [HR]: 0.77, 95% CI [confidence interval]: 0.66-0.91; p = 0.001), better PFS (HR: 0.77, 95% CI: 0.70-0.85; p < 0.00001) and comparable objective response rate (ORR) (risk ratio [RR]: 1.27, 95% CI: 0.98-1.65; p = 0.07); in terms of toxicity, CP was comparable to chemotherapy across all-grade adverse events (AEs) (RR: 0.87, 95% CI: 0.73-1.03; p = 0.11) and grade 3-5 AEs (RR: 0.85, 95% CI: 0.63-1.14; p = 0.27). Compared with P, CP had no superiority in efficacy in terms of the OS (HR: 1.04, 95%CI: 0.86-1.24; p=0.70), PFS (HR: 0.95, 95%CI: 0.75-1.22; p = 0.70) and the ORR (RR: 1.07, 95% CI: 0.95-1.21; p = 0.27) but CP was more effective than P when PD-L1 expression was <1% (RR: 0.77,95%CI: 0.60-0.98; p = 0.04); in terms of toxicity, CP was associated with increased all-grade AEs (RR:1.07, 95% CI: 0.97-1.19; p = 0.18) and grade 3-5 AEs (RR:1.58, 95% CI: 1.21-2.07; p = 0.0008).

WHAT IS NEW AND CONCLUSION

CP is a beneficial therapeutic schedule with longer PFS and OS than chemotherapy and has an acceptable, manageable grade 3-4 AE rate in IIIB/IV NSCLC. However, compared with P, CP results in better OS only in patients with PD-L1 expression <1%.