Outcomes and toxicity following high-dose radiation therapy in 15 fractions for non-small cell lung cancer

Evidence-based clinical recommendations for hypofractionated radiotherapy: exploring efficacy and safety - Part 2. Lung (non-small cell lung cancer)

Several recent studies have investigated the use of hypofractionated radiotherapy (HFRT) for various cancers. However, HFRT for non-small cell lung cancer (NSCLC) with or without concurrent chemotherapy is not yet widely used because of concerns about serious side effects and the lack of evidence for improved treatment results. Investigations of HFRT with concurrent chemotherapy in NSCLC have usually been performed in single-arm studies and with a small number of patients, so there are not yet sufficient data. Therefore, the Korean Society for Radiation Oncology Practice Guidelines Committee planned this review article to summarize the evidence on HFRT so far and provide it to radiation oncology clinicians. In summary, HFRT has demonstrated promising results, and the reviewed data support its feasibility and comparable efficacy for the treatment of locally advanced NSCLC. The incidence and severity of esophageal toxicity have been identified as major concerns, particularly when treating large fraction sizes. Strategies, such as esophagus-sparing techniques, image guidance, and dose constraints, may help mitigate this problem and improve treatment tolerability. Continued research and clinical trials are essential to refine treatment strategies, identify optimal patient selection criteria, and enhance therapeutic outcomes.

Coronavirus disease 2019 and lung cancer: where are we?

Oncology patients are more susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection due to hospital contact and an immunological system that can be compromised by antineoplastic therapy and supportive treatments. Certain similarities have been described in the physiopathology of coronavirus disease 2019 (COVID-19) and lung cancer (LC) that may explain the higher probability of these patients of developing a more serious disease with more frequent hospitalizations and even death, especially with the addition of smoking, cardiovascular and respiratory comorbidities, old age and corticosteroids use. Pre-existing lesions and cancer therapies change the normal architecture of the lungs, so diagnostic scales such as COVID-19 Reporting and Data System (CO-RADS) are of vital importance for a correct diagnosis and patient homogenization, with a high inter-observer correlation. Moreover, anticancer treatments have required an adaptation to reduce the number of visits to the hospital [hypofractionated radiotherapy (RT), larger intervals between chemotherapy cycles, delay in follow-up tests, among others]. In a way, this has also caused a delay in the diagnosis of new cancers. On the other hand, vaccination has had a positive impact on the mortality of these patients, who maintain a similar seroprevalence to the rest of the population, with a similar impact in mortality.

Tumor-suppressive E3 ubiquitin ligase CHIP inhibits the PBK/ERK axis to repress stem cell properties and radioresistance in non-small cell lung cancer

Recently, radioresistant cancer cells surviving radiotherapy have been suggested to show more aggressive phenotypes than parental cells, and the underlying mechanisms may be associated with cancer stem cells. This study provided novel mechanistic insights for E3 ubiquitin ligase CHIP in stem cell properties and radioresistance of non-small cell lung cancer (NSCLC). After bioinformatic prediction for key genes involved, NSCLC tissues and cells were collected to measure the expression of CHIP and PBK. E3 ubiquitin ligase CHIP was poorly expressed, while PBK was highly expressed in NSCLC tissues and cells. CHIP reduced the protein stability of PBK through the ubiquitin-protease pathway to repress the activation of ERK pathway. Based on the gain- or loss-of-function experiments, it was noted that restoration of CHIP curtailed stem cell properties and radioresistance in NSCLC, as manifested by inhibited sphere formation and cell proliferation, decreased number of CD133⁺CD44⁺ cells and expression of OCT4, SOX2, and NANOG, as well as facilitated apoptosis of NSCLC cells. Besides, in vivo animal experiments further confirmed that CHIP restrained tumorigenic ability and improved radiosensitivity of NSCLC cells by inhibiting PBK/ERK axis. Collectively, CHIP suppressed stem cell properties and radioresistance of NSCLC cells by inhibiting PBK/ERK axis, therefore offering a potential therapeutic target for enhancing efficacy of radiotherapy.

Hypofractionated radiation therapy for unresectable or metastatic sarcoma lesions

Purpose

Given the relative radioresistance of sarcomas and their often large size, conventional palliative radiation therapy (RT) often offers limited tumor control and symptom relief. We report on our use of hypofractionated RT (HFRT) as a strategy to promote durable local disease control and optimize palliation.

Methods and Materials

We retrospectively reviewed 73 consecutive patients with sarcoma who received >10 fractions of HFRT from 2017 to 2020. Clinical scenarios included: (1) palliative or symptomatic intent (34%), (2) an unresectable primary (27%), (3) oligometastatic disease (16%), and (4) oligoprogressive disease (23%).

Results

The HFRT target was a primary tumor in 64% of patients with a median dose of 45 Gy in 15 fractions (59% ≥45 Gy). The 1-year disease-specific survival was 59%, which was more favorable for patients receiving HFRT for oligometastatic (1-year 100%) or oligoprogressive (1-year 73%) disease (P = .001). The 1-year local control (LC) of targeted lesions was 73%. A metastatic target (1-year 95% vs 60% primary; P = .02; hazard ratio, 0.27; P = .04) and soft tissue origin (1-year 78% vs 61% bone; P = .01; hazard ratio, 0.33; P = .02) were associated with better LC. The rate of distant failure was high with a 6-month distant metastasis-free survival of only 43%. For patients not planned for adjuvant systemic therapy (n = 53), the median systemic therapy break was 9 months and notably longer in oligometastatic (13 months), oligoprogressive (12 months) or unresectable (13 months) disease. HFRT provided palliative relief in 95% of cases with symptoms. Overall, 49% of patients developed acute grade 1 to 2 RT toxicities (no grade 3-5). No late grade 2 to 5 toxicities were observed.

Conclusions

HFRT is an effective treatment strategy for patients with unresectable or metastatic sarcoma to provide durable LC, symptom relief, and systemic therapy breaks with limited toxic effects.

Predictors of Acute Radiation Dermatitis and Esophagitis in African American Patients Receiving Whole Breast Radiotherapy

PURPOSE/OBJECTIVES

Adjuvant whole breast radiotherapy following breast conserving surgery is standard of care in the management of early stage breast cancer. Two of the most common acute toxicities of breast radiotherapy are radiation esophagitis (RE) and radiation dermatitis (RD). African Americans are at higher risk for experiencing treatment-related toxicity and are often under-represented in clinical trials.

METHODS

An institutional database was developed to include all African American patients with history of breast cancer or DCIS undergoing adjuvant radiotherapy at a single institution from 2013-2019. Records were reviewed to identify patient age, BMI, radiation dose, prone vs supine position, inclusion of boost, and inclusion of regional nodal irradiation (RNI). Radiation treatment plans were reviewed to identify breast size as well as dosimetric parameters to the breast and esophagus. Medical records were reviewed to identify which patients were prescribed silvadene or mylanta-lidocaine during or immediately following their course of radiotherapy which was used as a surrogate for Grade 2 or higher dermatitis (G2RD) and esophagitis (G2RE), respectively.

RESULTS

272 patients were included in the final analysis. On univariable analysis, morbidly obese patients were more likely to develop G2RD while hypofractionated radiotherapy was associated with lower rates of G2RD. On multivariable analysis, increasing breast volume was associated with higher rates of G2RD. For the subset of patients receiving RNI, 19% of patients experienced G2RE with the best predictor on multivariable analysis being D_mean to the esophagus.

CONCLUSION

Radiation dermatitis and esophagitis are common toxicities in African American patients undergoing adjuvant breast radiotherapy. Breast size, irrespective of patient's BMI, was associated with worse rate of dermatitis. Prone position and hypofractionated radiation reduced rates of G2RD. D_mean to the esophagus was the dosimetric parameter best correlating with G2RE. These results may be used to help select patients are at higher risk for G2 or higher toxicity during radiotherapy.

Increased biologically effective dose (BED) to the primary tumor is associated with improved survival in patients with oligometastatic NSCLC

PURPOSE

Local consolidative therapy (LCT) for oligometastatic non-small cell lung cancer (NSCLC) is an evolving treatment paradigm. We investigated whether the biologically effective dose (BED) of consolidative radiation therapy (RT) to the primary tumor predicted for improved local control, progression-free survival (PFS), and overall survival (OS) among NSCLC patients presenting with oligometastatic disease.

MATERIALS AND METHODS

Patients presenting to a single institution (2000-2017) with stage IV NSCLC, ≤3 synchronous metastatic lesions at diagnosis, and treated with RT to the primary tumor were identified. Univariate and multivariable Cox proportional-hazards regression modeling were performed to identify factors associated with local recurrence-free survival (LRFS), PFS, and OS.

RESULTS

One hundred twenty-four patients were identified meeting our inclusion criteria. With a median follow-up of 55.1 months, median PFS and OS for the entire cohort were 11.0 months and 25.3 months, respectively. The median BED (α/β = 10) of RT to the primary tumor was 74.3 Gy. On univariate analysis, increased BED to the primary tumor predicted for improved PFS (p < 0.001) and LRFS (p = 0.01), with a median PFS of 8.5 vs 12.8 months and median LRFS of 23.4 vs 58.4 months between patients treated with BED < 75 Gy and ≥75 Gy, respectively. Increased BED to the primary tumor was also associated with significantly improved OS (p = 0.02); patients treated with a BED of <75 Gy demonstrated a median OS of 22.9 months vs 27.5 months if treated with BED ≥ 75 Gy. On multivariable analysis, primary site BED remained a significant predictor of OS (p = 0.02) and PFS (p = 0.002).

CONCLUSIONS

We found that delivery of >75 Gy BED RT regimens to the primary lesion in patients with synchronous oligometastatic NSCLC is associated with improved local control, PFS, and OS. These data support results of recent prospective trials and other ongoing prospective efforts to characterize therapeutic benefits associated with this management strategy.

GOECP/SEOR clinical recommendations for lung cancer radiotherapy during the COVID-19 pandemic

The coronavirus disease 2019 crisis has had a major and highly complex impact on the clinical practice of radiation oncology worldwide. Spain is one of the countries hardest hit by the virus, with devastating consequences. There is an urgent need to share experiences and offer guidance on decision-making with regard to the indications and standards for radiation therapy in the treatment of lung cancer. In the present article, the Oncological Group for the Study of Lung Cancer of the Spanish Society of Radiation Oncology reviews the literature and establishes a series of consensus-based recommendations for the treatment of patients with lung cancer in different clinical scenarios during the present pandemic.

Thoracic Radiation Therapy During Coronavirus Disease 2019: Provisional Guidelines from a Comprehensive Cancer Center within a Pandemic Epicenter

Coronavirus disease 2019 is an unprecedented pandemic with significant and evolving impact on the practice of radiation oncology. Radiation oncology departments must anticipate and account for coronavirus disease 2019 exposure risk for both patients and staff. The potential for severe radiation therapy resource constraints, particularly due to staff illness, must also be considered. Here we present provisional guidelines for thoracic radiation therapy adopted at our facility, a high-volume cancer center located in a United States pandemic epicenter. Generally, these guidelines reflect the principle that where evidence-supported hypofractionated schedules with comparable efficacy and toxicity exist, the shortest such schedules should be employed. In addition, we discuss potential adaptations in the prioritization and timing of radiation therapy for thoracic malignancies under these circumstances.

Alternative Multidisciplinary Management Options for Locally Advanced NSCLC During the Coronavirus Disease 2019 Global Pandemic

The coronavirus disease 2019 (COVID-19) pandemic is currently accelerating. Patients with locally advanced NSCLC (LA-NSCLC) may require treatment in locations where resources are limited, and the prevalence of infection is high. Patients with LA-NSCLC frequently present with comorbidities that increase the risk of severe morbidity and mortality from COVID-19. These risks may be further increased by treatments for LA-NSCLC. Although guiding data is scarce, we present an expert thoracic oncology multidisciplinary (radiation oncology, medical oncology, surgical oncology) consensus of alternative strategies for the treatment of LA-NSCLC during a pandemic. The overarching goals of these approaches are the following: (1) reduce the number of visits to a health care facility, (2) reduce the risk of exposure to severe acute respiratory syndrome–coronavirus-2, (3) attenuate the immunocompromising effects of lung cancer therapies, and (4) provide effective oncologic therapy. Patients with resectable disease can be treated with definitive nonoperative management if surgical resources are limited or the risks of perioperative care are high. Nonoperative options include chemotherapy, chemoimmunotherapy, and radiation therapy with sequential schedules that may or may not affect long-term outcomes in an era in which immunotherapy is available. The order of treatments may be on the basis of patient factors and clinical resources. Whenever radiation therapy is delivered without concurrent chemotherapy, hypofractionated schedules are appropriate. For patients who are confirmed to have COVID-19, usually, cancer therapies may be withheld until symptoms have resolved with negative viral test results. The risk of severe treatment-related morbidity and mortality is increased for patients undergoing treatment for LA-NSCLC during the COVID-19 pandemic. Adapting alternative treatment strategies as quickly as possible may save lives and should be implemented through communication with the multidisciplinary cancer team.

Definitive Radiotherapy for Inoperable Stage IIB Non-small-cell Lung Cancer: Patterns of Care and Comparative Effectiveness

BACKGROUND

The purpose of this study was to analyze practice patterns and perform comparative effectiveness of definitive radiotherapy techniques for inoperable stage IIB (American Joint Committee on Cancer eighth edition) non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

Adults in the National Cancer Database diagnosed with T3N0M0 or T1-2N1M0 NCSLC between 2004 and 2015 who received definitive radiotherapy were identified. Cases were divided as stereotactic body radiotherapy (SBRT), hypofractionated radiotherapy (HFRT), or conventionally fractionated radiotherapy (CFRT) and stratified by systemic therapy (ST). Cox proportional hazards models evaluated the effect of covariates on overall survival (OS). Subgroup analysis by tumor size, chest wall invasion, multifocality, and ST use was performed with Kaplan-Meier estimates of OS.

RESULTS

A total of 10,081 subjects met inclusion criteria: 4401 T3N0M0 (66.5% CFRT, 11.0% HFRT, and 22.5% SBRT) and 5680 T1-2N1M0 (92.5% CFRT and 7.5% HFRT). For T3N0M0 NSCLC, SBRT utilization increased from 3.7% in 2006% to 35.4% in 2015. Subjects treated with SBRT were more likely to have smaller tumors, multifocal tumors, or adenocarcinoma histology. SBRT resulted in similar or superior OS compared with CFRT for tumors > 5 cm, tumors invading the chest wall, or multifocal tumors. SBRT was significantly associated with improved OS on multivariate analysis (hazard ratio, 0.715; P < .001). For T1-2N1M0 NSCLC, patients treated with HFRT were significantly older and less likely to receive ST; nevertheless, there was no difference in OS between HFRT and CFRT on multivariate analysis.

CONCLUSION

CFRT + ST is utilized most frequently to treat stage IIB NSCLC in the United States when surgery is not performed, though it is decreasing. SBRT utilization for T3N0M0 NSCLC is increasing and was associated with improved OS.