Definitive radiotherapy with or without chemotherapy for clinical stage T4N0-1 non-small cell lung cancer

High-dose radiation-resistant lung cancer cells stored many functional lipid drops through JAK2/p-STAT3/FASN pathway

BACKGROUND

The understanding of radiation resistance is still unclear. This study aims to explore the new mechanism of radiation resistance in lung cancer from the perspective of lipid metabolism.

METHODS

Oil red O was used to detect the amount of lipid droplets in high-dose radiation-resistant lung cancer cells (HDRR-LCCs) and the primary lung cancer cells. Western blot analysis was used to determine the protein expression levels of key molecules related to de novo fatty acid synthesis and fatty acid transport. Orlistat was used to inhibit the de novo fatty acid synthesis. The prediction of the transcriptional regulators of fatty acid synthetase (FASN) was analyzed by bioinformatics. AZD-1480 was used to inhibit the JAK2/STAT3 pathway to observe its effects on FASN and intracellular lipid droplets. The regulation of the transcription factor p-STAT3 on the FASN gene was verified by Chip-qPCR. Finally, we used the public data of lung cancer patients to analyze the correlation between FASN and LPL gene expression with the prognosis.

RESULTS

There were more lipid drops in the HDRR-LCCs than in the primary lung cancer cells. HDRR-LCCs preferred de novo synthesis of fatty acids, and high expression of LPL homodimers indicated a high intake of extracellular fatty acids. The expression of FASN was increased in HDRR-LCCs compared with the primary lung cancer cells in a radiation-dose-dependent way, while LPL homodimers did not show such a trend. The lipid droplets, cell proliferation, and radiation resistance were decreased in HDRR-LCCs after orlistat treatment. Lipid droplets were significantly reduced, and the protein expression of FASN also decreased when using AZD-1480 to inhibit the JAK2/STAT3 pathway. The Chip-qPCR showed that p-STAT3 was the upstream regulator which binds to the promoter region of FASN. Survival analysis showed that high expression of the FASN gene was associated with a poor prognosis in lung cancer patients who received radiotherapy.

CONCLUSION

Our studies discovered that lipids deposited in HDRR-LCCs were due to endogenous de novo fatty acids synthesis and exogenous lipids uptake. JAK2/p-TAT3/FASN could be used as promising targets for radiotherapy sensitization. Our study provided a new theoretical basis for studying the mechanism of radiation resistance in lung cancer.

Long-term survival of patients with central or > 7 cm T4 N0/1 M0 non-small-cell lung cancer treated with definitive concurrent radiochemotherapy in comparison to trimodality treatment

ABSTARCT

BACKGROUND: To examine long-term-survival of cT4 cN0/1 cM0 non-small-cell lung carcinoma (NSCLC) patients undergoing definitive radiochemotherapy (ccRTx/CTx) in comparison to the trimodality treatment, neoadjuvant radiochemotherapy followed by surgery, at a high volume lung cancer center.

METHODS

All consecutive patients with histopathologically confirmed NSCLC (cT4 cN0/1 cM0) with a curative-intent-to-treat ccRTx/CTx were included between 01.01.2001 and 01.07.2019. Mediastinal involvement was excluded by systematic EBUS-TBNA or mediastinoscopy. Following updated T4-stage-defining-criteria initial staging was reassessed by an expert-radiologist according to UICC-guidelines [8th edition]. Outcomes were compared with previously reported results from patients of the same institution with identical inclusion criteria, who had been treated with neoadjuvant radiochemotherapy and resection. Factors for treatment selection were documented. Endpoints were overall-survival (OS), progression-free-survival (PFS), and cumulative incidences of isolated loco-regional failures, distant metastases, secondary tumors as well as non-cancer deaths within the first year.

RESULTS

Altogether 46 consecutive patients with histopathologically confirmed NSCLC cT4 cN0/1 cM0 [cN0 in 34 and cN1 in 12 cases] underwent ccRTx/CTx after induction chemotherapy (iCTx). Median follow-up was 133 months. OS-rates at 3-, 5-, and 7-years were 74.9%, 57.4%, and 57.4%, respectively. Absolute OS-rate of ccRTx/CTx at 5 years were within 10% of the trimodality treatment reference group (Log-Rank p = 0.184). The cumulative incidence of loco-regional relapse was higher after iCTx + ccRT/CTx (15.2% vs. 0% at 3 years, p = 0.0012, Gray's test) while non-cancer deaths in the first year were lower than in the trimodality reference group (0% vs 9.1%, p = 0.0360, Gray's test). None of the multiple recorded prognostic parameters were significantly associated with survival after iCTx + ccRT/CTx: Propensity score weighting for adjustment of prognostic factors between iCTx + ccRT/CTx and trimodality treatment did not change the results of the comparisons.

CONCLUSIONS

Patients with cT4 N0/1 M0 NSCLC have comparable OS with ccRTx/CTx and trimodality treatment. Loco-regional relapses were higher and non-cancer related deaths lower with ccRTx/CTx. Definitive radiochemotherapy is an adequate alternative for patients with an increased risk of surgery-related morbidity.

Construction of Radiation Surviving/Resistant Lung Cancer Cell Lines with Equidifferent Gradient Dose Irradiation

Radiotherapy plays an increasingly crucial role in the treatment of non-small cell lung cancer (NSCLC). Local tumor recurrence and tumor progression caused by intratumoral heterogeneity induced radiotherapy resistance remain the primary causes of radiotherapy failure. However, the lack of a suitable cell line model has hampered the exploration of the dynamic mechanisms of radiation resistance. We established 3 groups of equidifferent gradient dose irradiation surviving/resistant human lung cancer cell lines based on A549, H520, and H460 cells with clinical conventional fractionated radiotherapy (CFRT) (2 Gy × 20 F, 2 Gy × 30 F, and 2 Gy × 40 F). The radiosensitivity of the cells was detected by clone formation assay, EDU cell proliferation assay, neutral comet assay, and γ-H2AX immunofluorescence staining. The radiosensitivity and proliferation viability were increased in a received dose-dependent manner. Compared with parental cells, DNA double-strand breaks (DSBs) in cell lines that received higher-dose irradiation were significantly reduced. We successfully constructed equidifferent gradient dose irradiation surviving/resistant NSCLC cell lines whose radiation surviving and resistant abilities were increased in a received dose-dependent manner. This preclinical cell model could be used to dynamically observe and detect the radiation surviving/resistant biomarkers during radiotherapy stress, elucidate the mechanism of radiation resistance.

Comparison of early tumour-associated versus late deaths in patients with central or >7 cm T4 N0/1 M0 non-small-cell lung-cancer undergoing trimodal treatment: Only few risks left to improve

BACKGROUND

The optimal treatment for patients with locally advanced non-small-cell lung-cancer (NSCLC) cT4 cN0/1 cM0 is still under debate. The purpose of this study was to examine the long-term survival of cT4 cN0/1 cM0 NSCLC patients undergoing induction chemotherapy and concurrent radiochemotherapy before surgery.

METHODS

All consecutive patients with confirmed NSCLC (cT4 cN0/1 cM0) treated with neoadjuvant chemotherapy, concurrent radiochemotherapy (RT/CTx) (45-46 Gy) and surgical resection between 2000 and 2015 were included. According to the UICC guidelines (8th edition), T4 stage was reanalysed by an expert radiologist. The mediastinal staging was performed by systematic EBUS-TBNA or mediastinoscopy. The primary end-point was overall-survival (OS). The power to detect an increase of early tumour-associated mortality (hazard ratio > 3.5) within the first 5 years after treatment in comparison to late deaths beyond 96 months was >80%.

RESULTS

Overall, 67 patients were treated with concurrent RT/CTx. T4 criteria were fulfilled by all patients, and multiple T4 criteria by 53 patients. Seventy percent of patients had an initial PET/CT staging. The median follow-up period was 134 months. OS rates at 2, 5, 10 and 15 years were 83.6 ± 4.5%, 65.4 ± 5.9%, 53.3 ± 6.3% and 36.6 ± 6.8%, respectively. A total of 44.8% of patients achieved a pathologic complete response. In multivariable analysis, ypT category was the most predictive factor. OS at 5 years for ypT0 (n = 31) was 80.5%, and ypT1 (n = 11) was 62.5%. Main sites of failure were brain and pulmonary metastases in seven and three patients, respectively. The intercurrent annual death rate was estimated from the survival curve beyond 96 months and was found to be 4.75% (95% CI 2.40-9.27%). No significant increased mortality was observed during the first 5 years (annual death rate: 8.31% [95% CI 5.60-12.24%], hazard-ratio = 1.72 [95% CI 0.81-3.65]).

CONCLUSIONS

The effectiveness of this trimodality schedule is high in patients with cT4 cN0/1 cM0 NSCLC with excellent local control rates. Considering the annual death rate beyond 8 years of survival as an intercurrent death rate due to comorbidity, this treatment schedule reduces annual mortality to background even in the first 5 years after therapy.

Hospitalization and definitive radiotherapy in lung cancer: incidence, risk factors and survival impact

BACKGROUND

Unplanned hospitalization during cancer treatment is costly, can disrupt treatment, and affect patient quality of life. However, incidence and risks factors for hospitalization during lung cancer radiotherapy are not well characterized.

METHODS

Patients treated with definitive intent radiation (≥45 Gy) for lung cancer between 2008 and 2018 at a tertiary academic institution were identified. In addition to patient, tumor, and treatment related characteristics, specific baseline frailty markers (Charlson comorbidity index, ECOG, patient reported weight loss, BMI, hemoglobin, creatinine, albumin) were recorded. All cancer-related hospitalizations during or within 30 days of completing radiation were identified. Associations between baseline variables and any hospitalization, number of hospitalizations, and overall survival were identified using multivariable linear regression and multivariable Cox proportional-hazards models, respectively.

RESULTS

Of 270 patients included: median age was 66.6 years (31-88), 50.4% of patients were male (n = 136), 62% were Caucasian (n = 168). Cancer-related hospitalization incidence was 17% (n = 47), of which 21% of patients hospitalized (n = 10/47) had > 1 hospitalization. On multivariable analysis, each 1 g/dL baseline drop in albumin was associated with a 2.4 times higher risk of any hospitalization (95% confidence interval (CI) 1.2-5.0, P = 0.01), and baseline hemoglobin ≤10 was associated with, on average, 2.7 more hospitalizations than having pre-treatment hemoglobin > 10 (95% CI 1.3-5.4, P = 0.01). After controlling for baseline variables, cancer-related hospitalization was associated with 1.8 times increased risk of all-cause death (95% CI: 1.02-3.1, P = 0.04).

CONCLUSIONS

Our data show baseline factors can predict those who may be at increased risk for hospitalization, which was independently associated with increased mortality. Taken together, these data support the need for developing further studies aimed at early and aggressive interventions to decrease hospitalizations during treatment.

Neutrophil-lymphocyte ratio and a dosimetric factor for predicting symptomatic radiation pneumonitis in non-small-cell lung cancer patients treated with concurrent chemoradiotherapy

OBJECTIVES

To identify the factors that predict the progression of radiological radiation pneumonitis (RP) to symptomatic RP, and to evaluate the usefulness of the neutrophil-lymphocyte ratio (NLR) as a marker of RP severity and prognosis in stage III non-small cell lung cancer (NSCLC) patients treated with definitive concurrent chemoradiotherapy (CCRT).

MATERIALS AND METHODS

We retrospectively reviewed 61 patients treated between January 2010 and December 2015. Patients' demographic characteristics, clinical data, laboratory findings and treatment parameters were analyzed to determine the predictive factors associated with progression from radiological RP to symptomatic RP.

RESULTS

Forty-seven patients (77%) exhibited radiological RP at a median of 78 days after radiation therapy (RT) completion, and 15 (32%) of these patients developed symptomatic RP. The interval between RT completion and radiological RP presentation was shorter in patients who progressed to symptomatic RP (P = .001); progression was highly probable if this latency period was ≤2 months (P = .002). Stage and RT technique correlated with symptomatic RP development (P = .046 and P = .046, respectively). Among dosimetric factors, a V₂₀ (defined as the lung volume receiving ≥20 Gy) of >30% was the most significant predictor of symptomatic RP (P = .001). The NLR and C-reactive protein level at radiological RP were higher in patients who developed symptomatic RP (P = .067 and P = .012, respectively). On multivariate analysis, a V₂₀ >30% and an NLR at radiological RP >6 were associated with symptomatic RP development.

CONCLUSION

The NLR at radiological RP is a useful biomarker for predicting symptomatic RP development after CCRT in stage III NSCLC patients.

Comparison of survival rates between 3D conformal radiotherapy and intensity-modulated radiotherapy in patients with stage III non-small cell lung cancer

Purpose

Randomized trials showing a clear survival benefit of intensity-modulated radiotherapy (IMRT) over 3-dimensional conformal radiotherapy (3D-CRT) in the treatment of lung cancer are lacking. This study compared the survival rates of patients with stage III non-small cell lung cancer who were treated with either 3D-CRT or IMRT and analyzed the prognostic factors for survival.

Methods

From January 2008 to July 2015, 19 patients were treated with IMRT and 30 were treated with 3D-CRT in our institution. The choice between 3D-CRT and IMRT was determined by the physician based on tumor extent and general condition of the patients. The primary endpoint of this study was overall survival. The secondary endpoints were loco-regional recurrence-free survival, distant metastasis-free survival, and the incidence of radiation-induced lung and esophageal toxicities.

Results

The 1- and 2-year overall survival rates were 94.7% and 77.1% in the IMRT group and 76.7% and 52.5% in the 3D-CRT group, respectively. The overall survival rates of the IMRT group were higher than those of the 3D-CRT group; however, these differences were not statistically significant (P=0.072). Gross tumor volume was significantly associated with the overall survival rate. The 1- and 2-year loco-regional recurrence-free survival rates were 63.2% and 51% in the IMRT group and 67.5% and 48.1% in the 3D-CRT group (P=0.897), respectively. The 1- and 2-year distant metastasis-free survival rates were 78.9% and 68.4% in the IMRT group and 62.6% and 40.9% in the 3D-CRT group (P=0.120), respectively. Chemotherapy and treatment interruption were significantly associated with distant metastasis-free survival.

Conclusion

IMRT showed comparable or better overall survival compared with 3D-CRT in patients with stage III non-small cell lung cancer. To confirm the results of this study, further randomized prospective trials comparing IMRT with 3D-CRT are warranted.