Low-dose radiation therapy mobilizes antitumor immunity: New findings and future perspectives.

Radiotherapy has unique immunostimulatory and immunosuppressive effects. Although high-dose radiotherapy has been found to have systemic antitumor effects, clinically significant abscopal effects were uncommon on the basis of irradiating single lesion. Low-dose radiation therapy (LDRT) emerges as a novel approach to enhance the antitumor immune response due to its role as a leverage to reshape the tumor immune microenvironment (TIME). In this article, from bench to bedside, we reviewed the possible immunomodulatory role of LDRT on TIME and systemic tumor immune environment, and outlined preclinical evidence and clinical application. We also discussed the current challenges when LDRT is used as a combination therapy, including the optimal dose, fraction, frequency, and combination of drugs. The advantage of low toxicity makes LDRT potential to be applied in multiple lesions to amplify antitumor immune response in polymetastatic disease, and its intersection with other disciplines might also make it a direction for radiotherapy-combined modalities.

Safety and Tolerability of Low-Dose Radiation and Stereotactic Body Radiotherapy + Sintilimab for Treatment-Naïve Stage IV PD-L1+ Non-Small Cell Lung Cancer Patients.

PURPOSE: Low-dose radiotherapy (LDRT) may enhance the synergistic antitumor effect of combined immunotherapy and stereotactic body radiotherapy (SBRT). The safety and efficacy of this novel triple-combination therapy were evaluated for the first time as first-line treatment for patients with metastatic non-small cell lung cancer (NSCLC). PATIENTS AND METHODS: This prospective phase I study enrolled 29 patients and included a dose-escalation and dose-expansion phase. Patients received SBRT [30 Gray (Gy)/3f] to small lesions and LDRT (2 Gy/1f, 4 Gy/2f, or 10 Gy/5f) to a large lesion concurrently, followed by sintilimab (a programmed death-1 inhibitor). The primary endpoint was safety and tolerability; secondary endpoints included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS). RESULTS: No dose-limiting toxicities were observed during the dose-escalation phase; 4 Gy/2f was the recommended LDRT dose. Median follow-up was 15.6 months. Treatment-related adverse events (TRAE) occurred in 96.6% (28/29) of patients [grade ≥ 3; 20.7% (6/29)]; 2 patients (6.9%) discontinued due to TRAEs. Seven patients experienced pneumonitis (grade 2, n = 6; grade 3, n = 1). Immune-related adverse events were noted in 58.6% (17/29) of patients. In patients with tumor assessment (n = 28), ORR and confirmed ORR were 60.7% and 57.1%, respectively. Median PFS was 8.6 months (95% confidence interval, 3.7-16.5), and median OS was not reached. Exploratory analyses suggested both expanded and newly emerging T-cell receptor clonotypes were associated with better PFS. CONCLUSIONS: The findings indicate that the novel SBRT + LDRT + sintilimab therapy is safe and promising in patients with programmed death ligand-1-positive, driver gene-negative primary metastatic NSCLC.

Psychological distress and eustress in cancer and cancer treatment: Advances and perspectives.

Facing cancer diagnosis, patients with cancer are prone to psychological stress and consequent psychological disorders. The association between psychological stress and cancer has long been a subject of high interest. To date, preclinical studies have gradually uncovered the promotive effects of psychological distress on tumor hallmarks. In contrast, eustress may exert suppressive effects on tumorigenesis and beneficial effects on tumor treatment, which brings a practicable means and psychosocial perspective to cancer treatment. However, the underlying mechanisms remain incompletely understood. Here, by focusing on the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, as well as stress-related crucial neurotransmitters and hormones, we highlight the effects of distress and eustress on tumorigenesis, the tumor microenvironment, and tumor treatment. We also discuss the findings of clinical studies on stress management in patients with cancer. Last, we summarize questions that remain to be addressed and provide suggestions for future research directions.

Inflammation-nutritional markers of peripheral blood could predict survival in advanced non-small-cell lung cancer patients treated with PD-1 inhibitors.

BACKGROUND: Inflammation-nutritional markers of peripheral blood are easily assessed and can predict survival. The aim of this study was to investigate the association between inflammation-nutritional parameters and survival of anti-programmed death-1 (PD-1) therapy in non-small-cell lung cancer (NSCLC) patients. METHODS: We performed a retrospective study from March 2017 to April 2020 in advanced NSCLC patients treated with PD-1 inhibitors. Univariable and multivariable analyses were conducted to evaluate the relationship between peripheral blood parameters (absolute lymphocyte count [ALC], absolute neutrophil count [ANC], absolute monocyte count [AMC], absolute eosinocyte count [AEC], lactic dehydrogenase [LDH], plasma-albumin [ALB], neutrophil/lymphocyte ratio [NLR], and platelet/lymphocyte ratio [PLR]) measured before therapy initiation and prognosis. RESULTS: Among 184 evaluable patients, 134 (72.8%) were male and the median age was 58 years (range 33-87) with 31 (16.8%) ≥70 years. An elevated ANC (≥7500/ul), NLR (≥5), and PLR (≥200) was significantly associated with worse objective response rate (ORR), progression-free survival (PFS), and overall survival (OS), while increased ALC (≥1000/ul) and ALB (≥3.5 g/dl) could significantly improve survival in terms of ORR, PFS, and OS. In multivariate analyses, higher AEC (≥150/ul) and AMC (≥650/ul) could significantly decrease the risk of death (hazard ratio [HR] 0.363, 95% confidence interval [CI] 0.141-0.931, p = 0.035; HR 0.370, 95% CI 0.203-0.675, p = 0.001). A higher NLR and PLR, and lower ALB were independent predictors of poor prognosis for OS (HR 1.964, 95% CI 1.027-3.755, p = 0.041; HR 4.255, 95% CI 2.364-7.658, p = 0.000; HR 1.962, 95% CI 1.213-3.174, p = 0.006, respectively). CONCLUSION: Our research illustrated that pretreatment AEC, AMC, ALB, NLR, and PLR are independent predictors for survival in advanced NSCLC patients treated with PD-1 inhibitors.

Pseudoprogression and hyperprogression in lung cancer: a comprehensive review of literature.

PURPOSE: Immune checkpoint inhibitors are associated with clinical benefit in lung cancer. However, response patterns to immunotherapy, including pseudoprogression and hyperprogression, are difficult to diagnose, and their mechanisms remain unclear. This review aimed to describe two response patterns observed in lung cancer, namely pseudoprogression and hyperprogression, including their epidemiology, diagnostic characteristics, and plausible mechanisms. METHODS: We performed a comprehensive literature search in the PubMed database, using keywords "pseudoprogression", "hyperprogression", and "lung cancer", among others. The literature was examined for pseudoprogression and hyperprogression characteristics and plausible mechanisms. RESULTS: Pseudoprogression manifests in multiple forms; however, the immune system-related response criteria and biopsy data are helpful to make accurate diagnosis. Serological biomarkers, such as neutrophil-to-lymphocyte ratio (NLR) and circulating tumor DNA (ctDNA), might help distinguish pseudoprogression from true progression. The incidence of hyperprogression ranges within 5-19.2%, depending on definition. The unique response pattern of rapid progression is observed not only with immunotherapy, but also with other treatment regimens. Molecular mutations and amplifications may result in hyperprogression; however, the exact mechanism remains unclear. CONCLUSION: Atypical response patterns, such as pseudoprogression and hyperprogression, are increasingly common in clinical practice. Immune-related response criteria can help diagnose pseudoprogression. Molecular mechanisms of hyperprogression remain unclear. Biomarkers for pseudoprogression and hyperprogression are required.