Superior Treatment Response and In-field Tumor Control in Epidermal Growth Factor Receptor-mutant Genotype of Stage III Nonsquamous Non-Small cell Lung Cancer Undergoing Definitive Concurrent Chemoradiotherapy

Comparison of treatment regimens for unresectable stage III epidermal growth factor receptor (EGFR) mutant non-small cell lung cancer

BACKGROUND

Durvalumab after chemoradiotherapy (CRT) failed to bring survival benefits to patients with epidermal growth factor receptor (EGFR) mutations in PACIFIC study ( evaluating durvalumab in patients with stage III, unresectable NSCLC who did not have disease progression after concurrent chemoradiotherapy). We aimed to explore whether locally advanced inoperable patients with EGFR mutations benefit from tyrosine kinase inhibitors (TKIs) and the optimal treatment regimen.

METHODS

We screened the PubMed, Embase, the Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov databases from January 1, 2000 to December 31, 2022 and performed a meta-analysis based on a Bayesian framework, with progression-free survival (PFS) and overall survival (OS) as the primary endpoints.

RESULTS

A total of 1156 patients were identified in 16 studies that included 6 treatment measures, including CRT, CRT followed by durvalumab (CRT-Durva), TKI monotherapy, radiotherapy combined with TKI (RT-TKI), CRT combined with TKI (CRT-TKI), and TKI combined with durvalumab (TKI-Durva). The PFS after the TKI-containing treatments was significantly longer than after the TKI-free treatments (hazard ratio [HR] = 0.37, 95% confidence interval [CI], 0.20-0.66). The PFS of TKI monotherapy was significantly longer than CRT (HR = 0.66, 95% CI, 0.50-0.87) but shorter than RT-TKI (HR = 1.78, 95% CI, 1.17-2.67). Furthermore, the PFS of RT-TKI or CRT-TKI were both significantly longer than that of CRT or CRT-Durva. RT-TKI ranked first in the Bayesian ranking, with the longest OS (60.8 months, 95% CI = 37.2-84.3 months) and the longest PFS (21.5 months, 95% CI, 15.4-27.5 months) in integrated analysis.

CONCLUSIONS

For unresectable stage III EGFR mutant NSCLC, RT and TKI are both essential. Based on the current evidence, RT-TKI brings the best survival advantage, while CRT-TKI needs further estimation. Large randomized clinical trials are urgently needed to explore the appropriate application sequences of TKI, radiotherapy, and chemotherapy.

REGISTRATION

PROSPERO; https://www.crd.york.ac.uk/PROSPERO/; No. CRD42022298490.

The ASCENT Trial: a phase 2 study of induction and consolidation afatinib and chemoradiation with or without surgery in stage III EGFR-mutant NSCLC

BACKGROUND

The role of tyrosine kinase inhibitors (TKIs) in early-stage and metastatic oncogene-driven non-small cell lung cancer (NSCLC) is established, but it remains unknown how best to integrate TKIs with concurrent chemoradiotherapy (cCRT) in locally advanced disease. The phase 2 ASCENT trial assessed the efficacy and safety of afatinib and cCRT with or without surgery in locally advanced epidermal growth factor receptor (EGFR)-mutant NSCLC.

PATIENTS AND METHODS

Adults ≥18 years with histologically confirmed stage III (AJCC 7th edition) NSCLC with activating EGFR mutations were enrolled at Mass General and Dana-Farber/Brigham Cancer Centers, Boston, Massachusetts. Patients received induction afatinib 40 mg daily for 2 months, then cisplatin 75 mg/m2 and pemetrexed 500 mg/m2 IV every 3 weeks during RT (definitive or neoadjuvant dosing). Patients with resectable disease underwent surgery. All patients were offered consolidation afatinib for 2 years. The primary endpoint was the objective response rate (ORR) to induction TKI. Secondary endpoints were safety, conversion to operability, progression-free survival (PFS), and overall survival (OS). Analyses were performed on the intention-to-treat population.

RESULTS

Nineteen patients (median age 56 years; 74% female) were enrolled. ORR to induction afatinib was 63%. Seventeen patients received cCRT; 2/9 previously unresectable became resectable. Ten underwent surgery; 6 had a major or complete pathological response. Thirteen received consolidation afatinib. With a median follow-up of 5.0 years, median PFS and OS were 2.6 (95% CI, 1.4-3.1) and 5.8 years (2.9-NR), respectively. Sixteen recurred or died; 6 recurrences were isolated to CNS. The median time to progression after stopping consolidation TKI was 2.9 months (95% CI, 1.1-7.2). Four developed grade 2 pneumonitis. There were no treatment-related deaths.

CONCLUSION

We explored the efficacy of combining TKI with cCRT in oncogene-driven NSCLC. Induction TKI did not compromise subsequent receipt of multimodality therapy. PFS was promising, but the prevalence of CNS-only recurrences and rapid progression after TKI discontinuation speak to unmet needs in measuring and eradicating micrometastatic disease.

Targeted treatment for unresectable EGFR mutation-positive stage III non-small cell lung cancer: Emerging evidence and future perspectives

Epidermal growth factor receptor (EGFR) mutations are detected in up to one third of patients with unresectable stage III non-small cell lung cancer (NSCLC). The current standard of care for unresectable stage III NSCLC is consolidation durvalumab for patients who have not progressed following concurrent chemoradiotherapy (the 'PACIFIC regimen'). However, the benefit of immunotherapy, specifically in patients with EGFR mutation-positive (EGFRm) tumors, is not well characterized, and this treatment approach is not recommended in these patients, based on a recent ESMO consensus statement. EGFR-tyrosine kinase inhibitors (EGFR-TKIs) have demonstrated significant improvements in patient outcomes in EGFRm metastatic NSCLC. The benefits of these agents have also translated to patients with EGFRm early-stage resectable disease as adjuvant therapy. The role of EGFR-TKIs has yet to be prospectively characterized in the unresectable setting. Preliminary efficacy signals for EGFR-TKIs in unresectable EGFRm stage III NSCLC have been reported from a limited number of subgroup and retrospective studies. Several clinical trials are ongoing assessing the safety and efficacy of EGFR-TKIs in this patient population. Here, we review the current management of unresectable EGFRm stage III NSCLC. We outline the rationale for investigating EGFR-TKI strategies in this setting and discuss ongoing studies. Finally, we discuss the evidence gaps and future challenges for treating patients with unresectable EGFRm stage III NSCLC.

Real-world treatment patterns and clinical outcomes in EGFR-mutant locally advanced lung adenocarcinoma: A multi-center cohort study

Objective

To investigate the optimal management of patients with epidermal growth factor receptor gene (EGFR) mutant locally advanced non-small cell lung cancer (LA-NSCLC).

Methods

Patients with unresectable stage III lung adenocarcinoma (LAC) harboring EGFR mutations from 2012 to 2018 were analyzed retrospectively, and were categorized into three groups according to the primary treatment: chemoradiotherpy (CRT) (group 1), combined radiation therapy (RT) and EGFR-tyrosine kinase inhibitors (TKI) with/without chemotherapy (group 2), and EGFR-TKI alone until tumor progression (group 3). Inverse probability of multiple treatment weighting (IPTW) of propensity score was used to compare overall survival (OS) and progression free survival (PFS) between treatments and account for confounding.

Results

A total of 104, 105, and 231 patients were categorized into groups 1, 2, and 3, respectively. After IPTW adjustment, the median PFS for each group was 12.4, 26.2, and 16.2 months (log-rank P < 0.001), and the median OS was 51.0, 67.4 and 49.3 months (log-rank P = 0.084), respectively. Compared with those in group 1, patients in group 2 had significantly improved PFS [adjusted hazard ratio HR (aHR), 0.40; 95% confidence interval (CI): 0.29, 0.54; P < 0.001] and OS (aHR, 0.61; 95% CI: 0.38, 0.98; P = 0.039). Patients in group 3 had prolonged PFS (aHR, 0.66; 95% CI: 0.50, 0.87; P = 0.003), but not OS (aHR, 0.90; 95% CI: 0.62, 1.32; P = 0.595). Doubly robust IPTW analysis and multivariable Cox regression analysis yielded similar findings.

Conclusions

EGFR-TKIs after chemoradiation or combined with radiation alone correlated with the longest PFS and OS (versus CRT or TKIs alone) in patients with EGFR-mutant unresectable LA-NSCLC. Well-designed prospective trials were warranted.

Pattern of failure and clinical value of local therapy for oligo‐recurrence in locally advanced non‐small cell lung cancer after definitive chemoradiation: Impact of driver mutation status

INTRODUCTION

Considerable differences of treatment response and pattern of failure may exist between definitive chemoradiation (CRT) treated locally advanced non-small cell lung cancer (LA-NSCLC) patients. The clinical value of additional tyrosine kinase inhibitors (TKIs) before disease recurrence and salvage local therapy after initial recurrent disease remain controversial.

METHODS AND MATERIALS

Consecutive LA-NSCLC patients receiving definitive CRT and having definite results about driver mutations (EGFR, ALK and ROS1) were retrospectively reviewed. Initial recurrent disease was classified as in-field recurrence, out-of-field recurrence and distant metastasis. Recurrent disease occurred only in the brain or limited to ≤3 extra-cranial organs and ≤5 extra-cranial lesions, was defined as oligo-recurrence. Progression free survival and overall survival (OS) were calculated from diagnosis to disease progression or death, and to death, respectively. OS2 was measured from initial disease recurrence to death among patients who had recurrent disease.

RESULTS

Of the 153 enrolled patients, 39 had driver mutations and 13 received additional TKI therapy besides definitive CRT. Patients harboring driver mutations but without additional TKI therapy had a similar PFS and significantly longer OS (p = 0.032) than those without driver mutations. Additional TKI therapy prolonged PFS (p = 0.021) but not OS among patients with driver mutations. No significant difference of pattern of failure was observed between patient subgroups stratified by the status of driver mutations and the usage of additional TKI therapy. Furthermore, 57 of the 95 patients with initial recurrent disease developed oligo-recurrence and salvage local therapy significantly improved OS2 (p = 0.01) among patients with oligo-recurrence disease.

CONCLUSION

LA-NSCLC patients receiving definitive CRT generally had similar PFS and pattern of treatment failure, regardless of driver mutation status. Additional TKI therapy besides definitive CRT could prolong PFS but not OS. The majority of recurrent disease after definitive CRT belongs to oligo-recurrence and salvage local therapy may provide survival benefit.

Prognostic outcome of treatment modalities for epidermal growth factor receptor-mutated advanced lung cancer

BACKGROUND/AIMS

The treatment of epidermal growth factor receptor (EGFR)-mutated lung cancer cases has shown remarkable development in the past two decades. However, there have been limited studies comparing the prognostic effects of EGFR-tyrosine kinase inhibitor (TKI) and other treatment modalities. Therefore, we compared the survival outcomes of patients treated with EGFR-TKIs versus those treated with other treatment modalities.

METHODS

Patient data were collected from the Korean National Health Insurance Database, National Health Insurance Service- National Sample Cohort 2002 to 2015, which was released by the Korean National Health Insurance Service in 2015. The lung cancer group included patients (n = 2,003) initially diagnosed with lung cancer between January 2010 and December 2013. The main outcome was all-cause mortality. A Cox proportional hazard regression analysis was used to calculate the relative risk of mortality.

RESULTS

Among the newly diagnosed lung cancer cases, 1,004 (50.1%) were included in the analysis. A 15.1-month median survival benefit was observed in the EGFR-TKI group than that of the multimodality therapy group. The risk of mortality was as follows: EGFR-TKI treatment group (n = 142; hazard ratio [HR], 5.29; 95% confidence interval [CI], 3.57 to 7.86) and multimodality therapy group (n = 326; HR, 7.42; 95% CI, 5.19 to 10.63) compared to surgery only (n = 275).

CONCLUSION

Patients with advanced lung cancer harbouring EGFR mutations treated with EGFR-TKIs showed better median survival and lower risk of mortality than those in the multimodality therapy group. In the case of EGFR-mutated advanced lung cancer, there is room for downstaging in the TNM classification.

Targeted therapies for unresectable stage III non-small cell lung cancer

Until recently, the standard treatment in unresectable stage III non-small cell lung cancer was concurrent chemoradiotherapy, but often with dismal outcome. The introduction of consolidation treatment with immune checkpoint inhibitors has shifted the treatment landscape and prognosis of these patients. However, patients whose tumors harbors an epidermal growth factor receptor (EGFR) mutation derived less benefit, with an increased risk of immune-related adverse events. Moreover, current data suggested that patients with oncogenic addicted tumors, mainly EGFR-positive tumors, and also anaplastic lymphoma kinase (ALK)-positive have poorer progression free survival after chemoradiotherapy. Indeed, these tumors have also inferior distant control compared with those who have wild-type disease, especially in the central nervous system, highlighting the need for assessing the role of targeted therapies in this patient population. It is speculated that outcome could probably increase with a consolidation treatment strategy including an EGFR tyrosine kinase inhibitor. However, a personalized treatment approach is not considered standard of care in this setting due to lack of robust evidence, as the majority of trials were performed in unselected patients, number of patients is limited and the majority of these studies were underpowered. In this review we summarize the role of tyrosine kinase inhibitors in unresectable stage III NSCLC, specifically focusing on EGFR-mutant tumors.

Development and validation of a prediction model using molecular marker for long-term survival in unresectable stage III non-small cell lung cancer treated with chemoradiotherapy

Background

This study aimed to establish a predictive nomogram integrating epidermal growth factor receptor (EGFR) mutation status for 3‐ and 5‐year overall survival (OS) in unresectable/inoperable stage III non‐small cell lung cancer (NSCLC) treated with definitive chemoradiotherapy.

Methods

A total of 533 stage III NSCLC patients receiving chemoradiotherapy from 2013 to 2017 in our institution were included and divided into training and testing sets (2:1). Significant factors impacting OS were identified in the training set and integrated into the nomogram based on Cox proportional hazards regression. The model was subject to bootstrap internal validation and external validation within the testing set and an independent cohort from a phase III trial. The accuracy and discriminative capacity of the model were examined by calibration plots, C‐indexes and risk stratifications.

Results

The final multivariate model incorporated sex, smoking history, histology (including EGFR mutation status), TNM stage, planning target volume, chemotherapy sequence and radiation pneumonitis grade. The bootstrapped C‐indexes in the training set were 0.688, 0.710 for the 3‐ and 5‐year OS. For external validation, C‐indexes for 3‐ and 5‐year OS were 0.717, 0.720 in the testing set and 0.744, 0.699 in the external testing cohort, respectively. The calibration plots presented satisfying accuracy. The derivative risk stratification strategy classified patients into distinct survival subgroups successfully and performed better than the traditional TNM staging.

Conclusions

The nomogram incorporating EGFR mutation status could facilitate survival prediction and risk stratification for individual stage III NSCLC, providing information for enhanced immunotherapy decision and future trial design.

Lung cancer epidermal growth factor receptor mutations and radiotherapy response: A multicentre clinical study

Purpose

To examine the impact of epidermal growth factor receptor (EGFR) mutations on objective response to palliative lung radiotherapy in patients with metastatic non-small cell lung cancer (NSCLC).

Materials and Methods

A multicentre retrospective study was conducted of patients with metastatic NSCLC diagnosed between March 2010 and June 2012 who received palliative radiotherapy to the chest. Patients included for study had baseline imaging and follow-up imaging 1-3 months after radiotherapy. The primary endpoint was 1-3 month local objective imaging response by the Response Evaluation Criteria in Solid Tumours (RECIST). Patients were divided into EGFR mutation positive (EGFR+) and EGFR wild type (WT) cohorts for analysis.

Results

There were 121 patients for study inclusion: 89 (74%) were EGFR WT and 32 (26%) were EGFR+. The response rate between EGFR WT and EGFR+ cohorts was not significantly different (49 vs. 63%, p = 0.21). On multivariate analysis, initiation of a tyrosine kinase inhibitor (TKI) after radiotherapy was associated with a higher rate of response (OR: 5.07, 95%CI: 1.08-23.69, p = 0.039) but EGFR mutation status was not. For the EGFR+ cohort, patients with disease progression after initial management on a TKI had a worse response rate compared to patients who were TKI-naïve before starting radiotherapy (30 vs. 77%, p = 0.018). Local control was not statistically different between the EGFR cohorts.

Conclusion

The EGFR mutation status alone was not an independent predictor of objective radiographic response to palliative thoracic radiotherapy. Acquired resistance to TKI therapy may be associated with disease cross-resistance to palliative radiotherapy.

Radiotherapy for unresectable locally advanced non-small cell lung cancer: a narrative review of the current landscape and future prospects in the era of immunotherapy

Significant recent advances have occurred in the use of radiation therapy for locally advanced non-small cell lung cancer (LA-NSCLC). In fact, the past few decades have seen both therapeutic gains and setbacks in the evolution of radiotherapy for LA-NSCLC. The PACIFIC trial has heralded a new era of immunotherapy and has raised important questions for future study, such as the future directions of radiation therapy for LA-NSCLC in the era of immunotherapy. Modern radiotherapy techniques such as three-dimensional (3D) conformal radiotherapy and intensity-modulated radiotherapy (IMRT) provide opportunities for improved target conformity and reduced normal-tissue exposure. However, the low-dose radiation volume brought by IMRT and its effects on the immune system deserve particular attention when combing radiotherapy and immunotherapy. Particle radiotherapy offers dosimetric advantages and exhibits great immunoregulatory potential. With the ongoing improvement in particle radiotherapy techniques and knowledge, the combination of immunotherapy and particle radiotherapy has tremendous potential to improve treatment outcomes. Of particular importance are questions on the optimal radiation schedule in the settings of radio-immunotherapy. Strategies for the reduction of the irradiated field such as involved-field irradiation (IFI) and omission of clinical target volume (CTV) hold promise for better preservation of immune function while not compromising locoregional and distant control. In addition, different dose-fractionation regimens can have diverse effects on the immune system. Thus, prospective trials are urgently needed to establish the optimal dose fractionation regimen. Moreover, personalized radiotherapy which allows the tailoring of radiation dose to each individual's genetic background and immune state is of critical importance in maximizing the benefit of radiation to patients with LA-NSCLC.

Perspective on treatment for unresectable locally advanced non-small cell lung cancer with oncogene-driven mutation: a narrative review

The standard treatment of unresectable locally advanced non-small cell lung cancer (LA NSCLC) is concurrent chemoradiotherapy. With the addition of immunotherapy, patients with LA NSCLC received a significantly prolonged outcome, while patients with harboring epidermal growth factor receptor (EGFR) mutation benefited less. Tyrosine kinase inhibitors (TKIs) have revolutionized the treatment of stage IV with harboring EGFR mutation and anaplastic lymphoma kinase rearrangement, but there are few recommendations indicating whether TKI treatment is effective in unresectable NSCLC. Preclinical studies have shown that TKIs could have a radiosensitizing effect, which provided a rationale to consider the application TKI with radiotherapy. In this review, we summarize the clinical studies that have used TKIs in LA-NSCLC as well as ongoing trials, and discuss recent progress in research related to the efficacy of TKI for unresectable LA NSCLC patients. Recent results of small studies evaluating TKI therapy for LA NSCLC patients in combination with radiation or chemoradiation demonstrated promising efficacy, improved outcomes with a tolerable toxicity profile. However, there is a lack of strong evidence for TKI treatment in unresectable LA NSCLC, because of unpowered statistics, lack of molecular selection, or lack of large randomized arms. We prospect the combination of TKI and radiation or chemoradiation therapy might eventually replace the current standard treatment for patients with LA NSCLC harboring oncogene-driven mutation.

Modeling Resistance and Recurrence Patterns of Combined Targeted-Chemoradiotherapy Predicts Benefit of Shorter Induction Period

Optimal integration of molecularly targeted therapies, such as tyrosine kinase inhibitors (TKI), with concurrent chemotherapy and radiation (CRT) to improve outcomes in genotype-defined cancers remains a current challenge in clinical settings. Important questions regarding optimal scheduling and length of induction period for neoadjuvant use of targeted agents remain unsolved and vary among clinical trial protocols. Here, we develop and validate a biomathematical framework encompassing drug resistance and radiobiology to simulate patterns of local versus distant recurrences in a non-small cell lung cancer (NSCLC) population with mutated EGFR receiving TKIs and CRT. Our model predicted that targeted induction before CRT, an approach currently being tested in clinical trials, may render adjuvant targeted therapy less effective due to proliferation of drug-resistant cancer cells when using very long induction periods. Furthermore, simulations not only demonstrated the competing effects of drug-resistant cell expansion versus overall tumor regression as a function of induction length, but also directly estimated the probability of observing an improvement in progression-free survival at a given cohort size. We thus demonstrate that such stochastic biological simulations have the potential to quantitatively inform the design of multimodality clinical trials in genotype-defined cancers. SIGNIFICANCE: A biomathematical framework based on fundamental principles of evolution and radiobiology for in silico clinical trial design allows clinicians to optimize administration of TKIs before chemoradiotherapy in oncogene-driven NSCLC.

Precision radiotherapy for non-small cell lung cancer

Precision medicine is becoming the standard of care in anti-cancer treatment. The personalized precision management of cancer patients highly relies on the improvement of new technology in next generation sequencing and high-throughput big data processing for biological and radiographic information.

Systemic precision cancer therapy has been developed for years. However, the role of precision medicine in radiotherapy has not yet been fully implemented. Emerging evidence has shown that precision radiotherapy for cancer patients is possible with recent advances in new radiotherapy technologies, panomics, radiomics and dosiomics.

This review focused on the role of precision radiotherapy in non-small cell lung cancer and demonstrated the current landscape.

Differences in failure patterns according to the EGFR mutation status after proton beam therapy for early stage non-small cell lung cancer

We analyzed 135 patients (including 27 EGFR-mutant and 29 EGFR-wild) with T1-3N0M0 non-squamous NSCLC treated by PBT. Considering the 3-year cumulative incidence, the EGFR-mutant group showed a significantly lower infield failure rate (9% vs 27%, p = 0.02) and higher out-of-field failure rate (67% vs 40%, p = 0.02) than the EGFR-wild group.

Predictive model of the first failure pattern in patients receiving definitive chemoradiotherapy for inoperable locally advanced non-small cell lung cancer (LA-NSCLC)

Purpose

To analyze patterns of failure in patients with LA-NSCLC who received definitive chemoradiotherapy (CRT) and to build a nomogram for predicting the failure patterns in this population of patients.

Materials and methods

Clinicopathological data of patients with LA-NSCLC who received definitive chemoradiotherapy and follow-up between 2013 and 2016 in our hospital were collected. The endpoint was the first failure after definitive chemoradiotherapy. With using elastic net regression and 5-fold nested cross-validation, the optimal model with better generalization ability was selected. Based on the selected model and corresponding features, a nomogram prediction model was built. This model was also validated by ROC curves, calibration curve and decision curve analysis (DCA).

Results

With a median follow-up of 28 months, 100 patients experienced failure. There were 46 and 54 patients who experience local failure and distant failure, respectively. Predictive model including 9 factors (smoking, pathology, location, EGFR mutation, age, tumor diameter, clinical N stage, consolidation chemotherapy and radiation dose) was finally built with the best performance. The average area under the ROC curve (AUC) with 5-fold nested cross-validation was 0.719, which was better than any factors alone. The calibration curve revealed a satisfactory consistency between the predicted distant failure rates and the actual observations. DCA showed most of the threshold probabilities in this model were with good net benefits.

Conclusion

Clinicopathological factors could collaboratively predict failure patterns in patients with LA-NSCLC who are receiving definitive chemoradiotherapy. A nomogram was built and validated based on these factors, showing a potential predictive value in clinical practice.

Randomized phase II study of chemoradiotherapy with cisplatin + S-1 versus cisplatin + pemetrexed for locally advanced non-squamous non-small cell lung cancer: SPECTRA study

OBJECTIVES

SPECTRA is a multicenter, randomized phase II study of chemotherapy with cisplatin (CDDP) plus S-1 versus CDDP plus pemetrexed (PEM) in combination with thoracic radiotherapy (TRT) for locally advanced non-squamous non-small cell lung cancer, in order to determine which of these two regimens might be preferable for comparison with standard therapies in a future phase III study.

MATERIALS AND METHODS

Patients were randomly assigned to receive CDDP + S-1 (CDDP 60 mg/m² on day 1 and S-1 80 mg/m2 on days 1-14, every 4 weeks, up to 4 cycles) or CDDP + PEM (CDDP 75 mg/m² + PEM 500 mg/m² on day 1, every 3 weeks, up to 4 cycles) combined with TRT (60 Gy in 30 fractions). The primary endpoint was the 2-year progression-free survival (PFS) rate. The sample size had been set at 100 patients.

RESULTS

A total of 102 patients were randomized to receive CDDP + S-1 or CDDP + PEM (CDDP + S-1, n = 52; CDDP + PEM, n = 50) between January 2013 and October 2016. The results in the CDDP + S1 group and CDDP + PEM group were as follows: completion rates of TRT (60 Gy)/chemotherapy (4 cycles) was 92 %/73 % and 98 %/86 %, respectively; the response rates were 60 % and 64 %, respectively; median PFS after a median follow-up of 32.1 months, 12.7/13.8 months (hazard ratio [HR] = 1.16; 95 % confidence interval [CI], 0.73-1.84); 2-year PFS rate, 36.5 % (95 % CI, 23.5-49.6)/32.1 % (95 %CI, 18.9-45.4); median OS, 48.3/59.1 months (HR = 1.05; 95 %CI, 0.58-1.90); 2-year OS rate, 69.2 % (95 %CI, 56.7-81.8)/66.4 % (95 %CI, 53.0-79.9); Grade 3 toxicities: febrile neutropenia (12 %/2 %), anorexia (8 %/16 %), diarrhea (8 %/0 %), esophagitis (6 %/8 %), and neutropenia (35 %/50 %); Grade 2 or worse radiation pneumonitis, 15 % (8 patients)/4 % (2 patients).

CONCLUSION

The 2-year PFS rate in the CDDP + S-1 arm was higher than that in the CDDP + PEM arm. Both treatments were safe, with manageable toxicities.

Pattern of recurrence after CyberKnife stereotactic body radiotherapy for peripheral early non-small cell lung cancer

Background

The treatment efficacy after CyberKnife stereotactic body radiotherapy (SBRT) have not been adequately addressed. The purpose of this study was to investigate pattern of recurrence according to irradiation field after CyberKnife SBRT for early-stage non-small cell lung cancer (NSCLC).

Methods

This retrospective study included patients with peripheral cT1/2N0M0 NSCLC that was treated with SBRT using a CyberKnife between May 2013 and March 2016 at single institute and followed up by more than two imaging examinations. Both operable and inoperable patients were included. Overall survival (OS) and progression-free survival (PFS) curves were estimated using the Kaplan-Meier method with 95% confidence intervals (CI). Cumulative incidence curves of recurrence were calculated and compared using the Gray's test.

Results

Total 71 patients were included and analyzed in this study. The median follow-up period for surviving patients was 34 months (range, 7-64 months). The 2-year OS and PFS rate were 93% (95% CI: 83-97%) and 77% (95% CI: 65-86%), respectively. The 2-year cumulative incidence rate of infield recurrence and out-of-field recurrence were 6% (95% CI: 2-14%) and 17% (95% CI: 9-27%), respectively. Gross tumor volume (GTV) ≥9 mL and diagnosis-to-treatment interval (DTI) ≥90 days were significantly associated with infield recurrence (P<0.001 and P=0.007), and epidermal growth factor receptor (EGFR) mutation was significantly associated with out-of-field recurrence (P=0.014).

Conclusions

Treatment efficacy after CyberKnife SBRT for peripheral early-stage NSCLC was identical to previous conventional linac-based SBRT reports. With short follow-up period, it was found that GTV and DTI were the significant predictive factor of infield recurrence, and EGFR mutation was the significant predictive factor of out-of-field recurrence.