Developments in radiation techniques for thoracic malignancies

Added value of EUS-B-FNA to bronchoscopy and EBUS-TBNA in diagnosing and staging of lung cancer

Background

Bronchoscopy and EBUS are standard procedures in lung cancer work-up but have low diagnostic yield in lesions outside the central airways and hilar/mediastinal lymph nodes. Growing evidence on introducing the EBUS endoscope into the oesophagus (EUS-B) in the same session as bronchoscopy/EBUS gives access to new anatomical areas that can be safely biopsied.

Objective

To summarize the current evidence of the added value of EUS-B-FNA to bronchoscopy and EBUS-TBNA in lung cancer work-up.

Methods

A narrative review.

Results

Few randomized trials or prospective studies are available. Prospective studies show that add-on EUS-B-FNA increases diagnostic yield when sampling abnormal mediastinal lymph nodes, para-oesophageal lung and left adrenal gland. A large retrospective series on EUS-B-FNA from retroperitoneal lymph nodes suggests high diagnostic yield without safety concerns, as do casuistic reports on EUS-B-FNA from mediastinal pleural thickening, pancreatic lesions, ascites fluid and pericardial effusions. No study has systematically assessed both diagnostic yield, safety, patient reported outcomes, adverse events and costs.

Conclusion

The diagnostic value of add-on EUS-B to standard bronchoscopy and EBUS in lung cancer work-up appears very promising without safety concerns, giving the pulmonologist access to a variety of sites out of reach with other minimally invasive techniques. Little is known on patient-reported outcomes and costs. Future and prospective research should focus on effectiveness aspects to clarify whether overall benefits of add-on EUS-B sufficiently exceed overall downsides.

Diagnosis and management of pneumonitis following chemoradiotherapy and immunotherapy in stage III non-small cell lung cancer

BACKGROUND

In inoperable stage III NSCLC, the standard of care is chemoradiotherapy and adjuvant durvalumab (IO) for 12 months. Pneumonitis is the commonest toxicity leading to discontinuation of IO. A failure to distinguish between expected radiation-induced changes, IO pneumonitis and infection can lead to unnecessary durvalumab discontinuation. We investigated the use of a structured multidisciplinary review of CT-scans, radiation dose distributions and clinical symptoms for the diagnosis of IO pneumonitis.

METHODS

A retrospective study was conducted at an academic medical center for patients treated for stage III NSCLC with chemoradiotherapy and adjuvant durvalumab between 2018 and 2021. An experienced thoracic radiologist reviewed baseline and follow-up chest CT-scans, systematically scored radiological features suspected for pneumonitis using a published classification system (Veiga C, Radioth Oncol 2018), and had access to screenshots of radiation dose distributions. Next, two experienced thoracic oncologists reviewed each patients' case record, CT-scans and radiation fields. A final consensus diagnosis incorporating views of expert clinicians and the radiologist was made.

RESULTS

Among the 45 included patients, 14/45 (31.1%) had a pneumonitis scored in patient records and durvalumab was discontinued in 11/45 cases (24.4%). Review by the radiologist led to a diagnosis of immune-related pneumonitis only in 6/45 patients (13.3%). Review by pulmonary oncologists led to a diagnosis of immune-related pneumonitis in only 4/45 patients (8.9%). In addition a suspicion of an immune-related pneumonitis was rejected in 3 separate patients (6.7%), after the thoracic oncologists had reviewed the patients' radiation fields.

CONCLUSIONS

In patients treated using the PACIFIC regimen, multidisciplinary assessment of CT-scans, radiation doses and patient symptoms, resulted in fewer diagnoses of immune-related pneumonitis (8.9%). Our study underscores the challenges in accurately diagnosing either IO-related or radiation pneumonitis in patients undergoing adjuvant immunotherapy after chemoradiotherapy and highlights the need for multidisciplinary review in order to avoid inappropriate cessation of adjuvant IO.

The Preventive Effect of Endostar on Radiation-induced Pulmonary Fibrosis

BACKGROUND

Radiation-induced pulmonary fibrosis (RIPF) is a long-term complication of thoracic radiotherapy without effective treatment available.

OBJECTIVE

This study aimed to establish a RIPF mouse model and explore the therapeutic effects and mechanisms of recombinant human endostatin (Endostar).

METHODS

C57BL/6 mice received a 16-Gy dose of X-rays to the whole thorax with or without the administration of Endostar for 24 weeks.

RESULTS

Radiation-induced body weight loss was partially attenuated by Endostar (P<0.05). Endostar significantly reduced alveolar inflammation (P<0.05) and pulmonary fibrosis (P<0.001), as indicated by a decrease in the expression levels of collagen I and collagen IV in lung tissue (both P<0.001). Angiogenesis (as shown by CD31 immunohistochemistry) was also decreased (P<0.01). In irradiated mice, Endostar inhibited the transforming growth factor-β1 (TGF-β1)/drosophila mothers against the decapentaplegic 3 (Smad3)/extracellular regulated protein kinases (ERK) signaling pathway (all P<0.05). In vitro, Endostar treatment decreased the radiation-induced expression of TGF-β1, vascular endothelial growth factor (VEGF), p-Smad3, and p-ERK in alveolar epithelial cells and vascular endothelial cells (all P<0.05).

CONCLUSION

Endostar could alleviate RIPF through decreased antiangiogenic activity and inhibition of the TGF-β1/Smad3/ERK pathway.

Association between statin therapy dose intensity and radiation cardiotoxicity in non-small cell lung cancer: Results from the NI-HEART study

INTRODUCTION

Radiation cardiotoxicity is a dose-limiting toxicity and major survivorship issue for patients with non-small cell lung cancer (NSCLC) completing curative-intent radiotherapy, however patients' cardiovascular baseline is not routinely optimised prior to treatment. In this study we examined the impact of statin therapy on overall survival and post-radiotherapy cardiac events.

METHODS

Patients treated between 2015-2020 at a regional center were identified. Clinical notes were interrogated for baseline patient, tumor and cardiac details, and both follow-up cancer control and cardiac events. Three cardiologists verified cardiac events. Radiotherapy planning scans were retrieved for application of validated deep learning-based autosegmentation. Pre-specified Cox regression analyses were generated with varying degrees of adjustment for overall survival. Fine and Gray regression for the risk of cardiac events, accounting for the competing risk of death and cardiac covariables was undertaken.

RESULTS

Statin therapy was prescribed to 59% of the 478 included patients. The majority (88%) of patients not prescribed a statin had at least one indication for statin therapy according to cardiovascular guidelines. In total, 340 patients (71%) died and 79 patients (17%) experienced a cardiac event. High-intensity (HR 0.68, 95%CI 0.50-0.91, p = 0.012) and medium-intensity (HR 0.70, 95%CI 0.51-0.97, p = 0.033) statin therapy were associated with improved overall survival after adjustment for patient, cancer, treatment, response and cardiovascular clinical factors. There were no consistent differences in the rate or grade of cardiac events according to statin intensity.

CONCLUSIONS

Statin therapy is associated with improved overall survival in patients receiving curative-intent radiotherapy for NSCLC, and there is evidence of a dose-response relationship. This study highlights the importance of a pre-treatment cardiovascular risk assessment in this cohort. Further studies are needed to examine if statin therapy is cardioprotective in patients undergoing treatment for NSCLC with considerable incidental cardiac radiation dose and a low baseline cardiac risk.

Health Economic Evaluation of Proton Therapy for Lung Cancer: A Systematic Review

BACKGROUND

To our knowledge, there have been no systematic reviews of health economic evaluations of proton therapy specific to lung cancer.

METHODS

We conducted this systematic review according to the predefined protocol [PROSPERO CRD42022365869]. We summarized the results of the included studies via structured narrative synthesis.

RESULTS

We identified four studies (all used passively scattered proton therapy) from 787 searches. Two cost analyses reported that proton therapy was more costly than photon therapy for early- or locally advanced-stage non-small cell lung cancer, one cost-utility analysis reported that proton therapy was dominated by nonproton therapy in early-stage non-small cell lung cancer, and one cost-utility analysis reported that proton therapy was not cost-effective (vs. photon) in locally advanced non-small cell lung cancer.

CONCLUSIONS

Passively scattered proton therapy was more costly and not cost-effective than photon therapy for early- and locally advanced-stage non-small cell lung cancer. Further health economic evaluations regarding modern proton therapy (such as scanning beam) for common radiotherapy indications of lung cancer are eagerly awaited.

Patients with Lower Positive Lymph Nodes Ratio May Benefit from Preoperative Radiotherapy in Stage III Non-Small Cell Lung Cancer

BACKGROUND

Although preoperative radiotherapy (PORT) is a promising therapeutic option for stage III non-small cell lung cancer (NSCLC), the efficacy of this treatment remains controversial. The positive lymph node ratio (PLNR) is recognized as an independent prognostic factor for survival. However, no previous studies have focused on the association between PLNR and PORT in stage III NSCLC.

METHODS

Data were collected from the Surveillance, Epidemiology and End Results (SEER) database, and all patients enrolled in this analysis were diagnosed during 2010-2015. The primary endpoint was overall survival (OS). Univariate and multivariate Cox regression analysis was used to identify factors associated with survival before and after case-control matching. PLNR was defined as the ratio of the number of positive lymph nodes to the total number of retrieved or examined lymph nodes. A cutoff value for PLNR was calculated using an X-tile model.

RESULTS

Overall, 391 patients with PORT and 2814 patients without PORT were enrolled in this study. The cohort after 1:1 case-control matching included 322 patients who received PORT and 322 patients without PORT. PORT was not associated with a significant effect on OS (HR  =  1.14; 95% CI: 0.91-1.43; P  =  0.825). Multivariate Cox regression analysis showed that PLNR (P < 0.001) was independently associated with OS in patients with stage III NSCLC. An X-tile model was used to identify a cutoff value for PLNR: the risk of death was significantly lower in patients with PLNR ≤0.41 who received PORT than in those with PLNR >0.41 who received PORT (HR  =  0.59; 95% CI: 0.38-0.91; P  =  0.015).

CONCLUSION

PLNR may be a prognostic factor for survival in patients with stage III NSCLC who undergo PORT. Lower PLNR is a predictor of better OS and thus warrants further study.

The Multidisciplinary Approach in Stage III Non-Small Cell Lung Cancer over Ten Years: From Radiation Therapy Optimisation to Innovative Systemic Treatments

Background: About 30% of new non-small cell lung cancer (NSCLC) cases are diagnosed at a locally advanced stage, which includes a highly heterogeneous group of patients with a wide spectrum of treatment options. The management of stage III NSCLC involves a multidisciplinary team, adequate staging, and a careful patient selection for surgery or radiation therapy integrated with systemic treatment. Methods: This is a single-center observational retrospective and prospective study including a consecutive series of stage III NSCLC patients who were referred to the Veneto Institute of Oncology and University Hospital of Padova (Italy) between 2012 and 2021. We described clinico-pathological characteristics, therapeutic pathways, and treatment responses in terms of radiological response in the entire study population and in terms of pathological response in patients who underwent surgery after induction therapy. Furthermore, we analysed survival outcomes in terms of relapse-free survival (RFS) and overall survival (OS). Results: A total of 301 patients were included. The majority of patients received surgical multimodality treatment (n = 223, 74.1%), while the remaining patients (n = 78, 25.9%) underwent definitive CRT followed or not by durvalumab as consolidation therapy. At data cut-off, 188 patients (62.5%) relapsed and the median RFS (mRFS) of the entire population was 18.2 months (95% CI: 15.83−20.57). At the time of analyses 140 patients (46.5%) were alive and the median OS (mOS) was 44.7 months (95% CI: 38.4−51.0). A statistically significant difference both in mRFS (p = 0.002) and in mOS (p < 0.001) was observed according to the therapeutic pathway in the entire population, and selecting patients treated after 2018, a significant difference in mRFS (p = 0.006) and mOS (p < 0.001) was observed according to treatment modality. Furthermore, considering only patients diagnosed with stage IIIB-C (N = 131, 43.5%), there were significant differences both in mRFS (p = 0.047) and in mOS (p = 0.022) as per the treatment algorithm. The mRFS of the unresectable population was 16.3 months (95% CI: 11.48−21.12), with a significant difference among subgroups (p = 0.030) in favour of patients who underwent the PACIFIC-regimen; while the mOS was 46.5 months (95% CI: 26.46−66.65), with a significant difference between two subgroups (p = 0.003) in favour of consolidation immunotherapy. Conclusions: Our work provides insights into the management and the survival outcomes of stage III NSCLC over about 10 years. We found that the choice of radical treatment impacts on outcome, thus suggesting the importance of appropriate staging at diagnosis, patient selection, and of the multidisciplinary approach in the decision-making process. Our results confirmed that the PACIFIC trial and the following introduction of durvalumab as consolidation treatment may be considered as a turning point for several improvements in the diagnostic-therapeutic pathway of stage III NSCLC patients.

Immunobiology of cancer-associated fibroblasts in the context of radiotherapy

Radiotherapy (RT) still represents a mainstay of treatment in clinical oncology. Traditionally, the effectiveness of radiotherapy has been attributed to the killing potential of ionizing radiation (IR) over malignant cells, however, it has become clear that therapeutic efficacy of RT also involves activation of innate and adaptive anti-tumor immune responses. Therapeutic irradiation of the tumor microenvironment (TME) provokes profound cellular and biological reconfigurations which ultimately may influence immune recognition. As one of the major constituents of the TME, cancer-associated fibroblasts (CAFs) play central roles in cancer development at all stages and are recognized contributors of tumor immune evasion. While some studies argue that RT affects CAFs negatively through growth arrest and impaired motility, others claim that exposure of fibroblasts to RT promotes their conversion into a more activated phenotype. Nevertheless, despite the well-described immunoregulatory functions assigned to CAFs, little is known about the interplay between CAFs and immune cells in the context of RT. In this review, we go over current literature on the effects of radiation on CAFs and the influence that CAFs have on radiotherapy outcomes, and we summarize present knowledge on the transformed cellular crosstalk between CAFs and immune cells after radiation.