Posttreatment Immune Parameters Predict Cancer Control and Pneumonitis in Stage I Non-Small-Cell Lung Cancer Patients Treated With Stereotactic Ablative Radiotherapy

Brachytherapy for high grade prostate cancer induces distinct changes in circulating CD4 and CD8 T cells - Implications for systemic control

This exploratory study is a follow up to our previous investigation of immune response in the circulation of high-grade Gleason 9 prostate cancer patients treated with EBRT + BT compared to EBRT alone. Notably, EBRT + BT demonstrates the potential to elicit an effect on CD4/CD8 ratio which may have attributed to improved clinical response to therapy. Our findings show promise for leveraging circulating immune cells as predictive biomarkers for radiotherapy response.

Tumor microenvironment shows an immunological abscopal effect in patients with NSCLC treated with pembrolizumab-radiotherapy combination

Background

Immunotherapy is currently part of the standard of care for patients with advanced-stage non-small cell lung cancer (NSCLC). However, many patients do not respond to this treatment, therefore combination strategies are being explored to increase clinical benefit. The PEMBRO-RT trial combined the therapeutic programmed cell death 1 (PD-1) antibody pembrolizumab with stereotactic body radiation therapy (SBRT) to increase the overall response rate and study the effects on the tumor microenvironment (TME).

Methods

Here, immune infiltrates in the TME of patients included in the PEMBRO-RT trial were investigated. Tumor biopsies of patients treated with pembrolizumab alone or combined with SBRT (a biopsy of the non-irradiated site) at baseline and during treatment were stained with multiplex immunofluorescence for CD3, CD8, CD20, CD103 and FoxP3 for lymphocytes, pan-cytokeratin for tumors, and HLA-ABC expression was determined.

Results

The total number of lymphocytes increased significantly after 6 weeks of treatment in the anti-PD-1 group (fold change: 1.87, 95% CI: 1.06 to 3.29) and the anti-PD-1+SBRT group (fold change: 2.29, 95% CI: 1.46 to 3.60). The combination of SBRT and anti-PD-1 induced a 4.87-fold increase (95% CI: 2.45 to 9.68) in CD103⁺ cytotoxic T-cells 6 weeks on treatment and a 2.56-fold increase (95% CI: 1.03 to 6.36) after anti-PD-1 therapy alone. Responders had a significantly higher number of lymphocytes at baseline than non-responders (fold difference 1.85, 95% CI: 1.04 to 3.29 for anti-PD-1 and fold change 1.93, 95% CI: 1.08 to 3.44 for anti-PD-1+SBRT).

Conclusion

This explorative study shows that that lymphocyte infiltration in general, instead of the infiltration of a specific lymphocyte subset, is associated with response to therapy in patients with NSCLC.

Furthermore, anti-PD-1+SBRT combination therapy induces an immunological abscopal effect in the TME represented by a superior infiltration of cytotoxic T cells as compared with anti-PD-1 monotherapy.

Comparison of Radiation Pneumonitis in Lung Cancer Patients Treated with HT versus IMRT and Circulating Lymphocyte Subsets as Predicting Risk Factors

Purpose

We sought to compare the symptomatic radiation pneumonitis (RP) in lung cancer patients treated with helical tomotherapy (HT) versus intensity-modulated radiotherapy (IMRT), and examine the predictive value of circulating lymphocyte subsets affecting the occurrence of RP.

Patients and Methods

Circulating lymphocyte subsets, clinical characteristics, dosimetric parameters and pulmonary function were collected from 130 lung cancer patients treated with HT (n = 53) or IMRT (n = 77) from 2016 through 2020. Symptomatic RP was compared between groups. Binary logistic regression was used to identify predictors of RP.

Results

The IMRT group had larger planning target volume (319.9 vs 240.8 cc, P = 0.041); more ECOG performance status 0–1 (96.1% vs 79.2%, P = 0.002); more stage III–IV disease (94.8% vs 37.6%, P = 0.028); and more combined systemic therapy (85.7% vs 69.8%, P = 0.022). Grade ≥2 RP were comparable between IMRT and HT groups (16.9% vs 15.1%, P = 0.785). For stage III–IV disease, IMRT was associated with lower lung V10 (31.9% vs 35.8%, P = 0.047) and lower incidence of grade 5 RP (0% vs 9.1%, P = 0.018). All lymphocyte subsets reduced after radiotherapy. The decrease degree of total T cell count and CD4⁺ T cell count were larger after IMRT than HT (P = 0.043, P = 0.021). In univariate analysis, the smoking status, lower baseline FEV1, and higher total T cell count, higher CD8⁺ T cell count, lower total B cell count, lower CD4⁺/CD8⁺ ratio after radiotherapy were associated with the development of grade ≥2 RP. The higher CD8⁺T cell count after radiotherapy was the only risk factor associated with grade ≥2 RP in multivariable analysis (OR 1.003; 95% CI: 1.000–1.005; P = 0.044).

Conclusion

IMRT was associated with lower lung V10 and less grade 5 RP than HT for stage III–IV lung cancer. Higher CD8⁺ T cell count after radiotherapy was associated with an increased risk of RP. HT may better preserve total T cell and CD4⁺ T cell than IMRT.

Circulating tumor cells counts are associated with CD8+ T cell levels in programmed death-ligand 1-negative non-small cell lung cancer patients after radiotherapy: A retrospective study

This study aimed to explore the dynamics of circulating tumor cells (CTCs) and CD8+ T cells in stage II-III non-small cell lung cancer patients with CTCs in different programmed death-ligand 1 (PD-L1) status treated with radiotherapy and evaluate the correlation between CTCs and CD8+ T cells.This study was a retrospective study which reviewed 69 stage II-III non-small cell lung cancer patients underwent postoperative radiotherapy and peripheral blood tests of CTCs and T lymphocyte were available before radiation, 1 week after radiation and 1 month after radiation.In this study, 25 patients had PD-L1 positive CTCs and 44 patients had PD-L1 negative CTCs. The CTCs count was significantly decreased compared with baseline in patients with different PD-L1 status CTCs at 1 week and 1 month after radiotherapy. The proportion of CD8+ T cells was significantly increased at 1 month after radiotherapy compared with baseline in the total population (mean change, 7.24 ± 2.12; P < .05) and patients with PD-L1 negative CTCs (mean change, 7.17 ± 2.65; P < .05). One month after radiotherapy, the proportion of CD8+ T cells was negatively correlated with the CTCs count in the total population (r = -0.255, P = .034) and PD-L1 negative patients (r = -0.330, P = .029). In patients with PD-L1 negative CTCs, the CTCs count 1 week after radiotherapy (hazard ratio, 0.150 [95% confidence intervals., 0.027-0.840], P = .031) and the proportion of CD8+ T cells 1 month after radiotherapy (hazard ratio, 7.961 [95% confidence intervals, 1.028-61.68], P = .047) were independent prognostic factors for disease recurrence.After radiotherapy, only PD-L1-negative patients had a significant increase in the CD8+ T cell levels, while it was negatively correlated with CTCs count and was an independent prognostic factors of disease recurrence.

Changes in T Lymphocyte Subsets in Different Tumors Before and After Radiotherapy: A Meta-analysis

Purpose

Radiation therapy (RT) induces an immune response, but the relationship of this response with tumor type is not fully understood. This meta-analysis further elucidated this relationship by analyzing the changes in T lymphocyte subsets in different tumors before and after radiotherapy.

Methods

We searched English-language electronic databases including PubMed, EMBASE, and the Cochrane Library to collect studies on the changes in peripheral blood CD3+ T lymphocytes, CD4+ T lymphocytes, and CD8+ T lymphocytes before and after radiotherapy in tumor patients from January 2015 to April 2021. The quality of the included literature was evaluated using the NOS scale provided by the Cochrane Collaboration, and statistical software RevMan 5.4 was used to analyze the included literature. P<0.05 was considered to indicate statistical significance.

Results

A total of 19 studies in 16 articles involving 877 tumor patients were included. All data were collected within 1 month before or after radiotherapy. Meta-analysis showed that numbers of CD3+ T lymphocytes (SMD: -0.40; 95% CI [-0.75, -0.04]; p = 0.03) and CD4+ T lymphocytes (SMD: -0.43; 95% CI: [-0.85, -0.02]; p = 0.04) were significantly reduced after radiotherapy compared with before treatment, but there was no statistically significant difference for CD8+ T lymphocytes (SMD: 0.33; 95% CI: [-0.88, 0.74]; p = 0.12). Subgroup analysis showed that peripheral blood T lymphocytes decreased in head and neck cancer. However, in prostate cancer and breast cancer, there was no significant change in peripheral blood. 1 month after radiotherapy, it has a potential proliferation and activation effect on lymphocytes in esophageal cancer and lung cancer. The results showed that CD8+T lymphocytes increased in peripheral blood after SBRT. Radiotherapy alone reduced CD3+ T lymphocyte numbers.

Conclusions

Within 1 month of radiotherapy, patients have obvious immunological changes, which can cause apoptosis and reduction of T lymphocytes, and affect the balance of peripheral blood immune cells. The degree of immune response induced by radiotherapy differed between tumor types.

Current status of immune checkpoint inhibition in early-stage NSCLC

Immune checkpoint inhibition (ICI) immunotherapy has revolutionized the approach to metastatic non-small-cell lung cancer (NSCLC). In particular, antibodies blocking the inhibitory immune checkpoints programmed death 1 (PD-1) and its ligand (PD-L1) are associated with higher response rates, improved overall survival and better tolerability as compared with conventional cytotoxic chemotherapy. Recently, ICI has moved from the second-line to the first-line setting for many patients with non-oncogene-addicted NSCLC, either alone or in combination with chemotherapy. The next logical step is to examine this therapy in patients with non-metastatic NSCLC to improve long-term overall survival and cure rates. For patients with unresectable stage III NSCLC, ICI with durvalumab after concurrent chemoradiotherapy has brought a major improvement in 2-year progression-free and overall survival, which holds promise for an improved cure rate. As the relapse pattern in patients with completely resected early-stage NSCLC is predominantly systemic, high expectations rest on the integration of ICI therapy in their treatment approach. A large number of studies with adjuvant or neo-adjuvant ICI are ongoing and will be discussed here. The advent of stereotactic ablative radiotherapy has brought a valid alternative treatment of patients unfit for or not willing to undergo surgery. Data on combining systemic therapy and stereotactic ablative radiotherapy are virtually non-existent, but there is a strong biological rationale to combine radiotherapy and ICI therapy. Early findings in small feasibility studies are promising and now need to be explored in well-designed phase III trials.

Increased CD8+CD28+ T cells independently predict better early response to stereotactic ablative radiotherapy in patients with lung metastases from non-small cell lung cancer

Background

Stereotactic ablative radiotherapy (SABR) shows a remarkable local control of non-small cell lung cancer (NSCLC) metastases, partially as a result of host immune status. However, the predictors of immune cells for tumor response after SABR are unknown. To that effect, we investigated the ability of pre-SABR immune cells in peripheral blood to predict early tumor response to SABR in patients with lung metastases from NSCLC.

Methods

This study included 70 patients with lung metastases from NSCLC who were undergoing SABR. We evaluated the early tumor response 1 month and 6 months after SABR in these patients following RECIST 1.1 guidelines. Pre-SABR peripheral CD8+ T cell count, CD8+CD28+ T-cell count, CD8+CD28− T-cell count, CD4+ T-cell count, and Treg-cell count were measured using flow cytometry.

Results

Increased CD8+CD28+ T-cell counts (14.43 ± 0.65 vs. 10.21 ± 0.66; P = 0.001) and CD4/Treg ratio (16.96 ± 1.76 vs. 11.91 ± 0.74; P = 0.011) were noted in 1-month responsive patients, compared with non-responsive patients. In univariate logistic analyses, high CD8+CD28+ T-cell counts (OR 0.12, 95% CI 0.03–0.48; P = 0.003), CD4/Treg ratio (OR 0.24, 95% CI 0.06–0.90; P = 0.035), and BED₁₀ (OR 0.91, 95% CI 0.84–0.99; P = 0.032) predicted a 1-month tumor response to SABR. According to multivariate logistic analyses, the CD8+CD28+ T-cell count predicted a 1-month tumor response to SABR (OR 0.19, 95% CI 0.04–0.90; P = 0.037) independently. Furthermore, we confirmed the independent predictive value of the CD8+CD28+ T-cell count in predicting tumor response to SABR in 41 patients 6 months after treatment (OR 0.08, 95% CI 0.01–0.85; P = 0.039).

Conclusions

A pre-SABR CD8+CD28+ T-cell count could predict early tumor response to SABR in patients with lung metastases from NSCLC. Larger, independently prospective analyses are warranted to verify our findings.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1872-9) contains supplementary material, which is available to authorized users.