Survival After Stereotactic Body Radiation Therapy for Clinically Diagnosed or Biopsy-Proven Early-Stage NSCLC: A Systematic Review and Meta-Analysis

Surgery and Stereotactic Radiotherapy for Stage I Small-Cell Lung Carcinoma: A 25-Year Experience

OBJECTIVES

Small-cell lung carcinoma (SCLC) is usually a wide-spread, highly-lethal malignancy but occasionally presents as localized, limited stage cancer amenable to local treatment. We reviewed our experience using surgery or stereotactic body radiotherapy (SBRT) to assess safety, survival rates and treatment toxicity in clinical stage I SCLC patients.

MATERIALS AND METHODS

Electronic medical records of patients with clinical stage I lymph node-negative SCLC who underwent surgical resection or SBRT between 1996 and 2021 were retrospectively reviewed. A multivariable Cox Proportional Hazards model was constructed.

RESULTS

Of 96 patients meeting inclusion criteria, 77 underwent resection and 19 underwent SBRT. Surgical patients were younger (mean 68.4 ± 9.2 years surgery versus 74.3 ± 6.6 years SBRT, P = .005) and had better pulmonary function (81.5 ± 19.6 FEV1% of predicted surgery versus 44.0 ± 20.9% SBRT, P < .001). SBRT patients had significantly more comorbidities. For both cohorts, 59 tumors were pure SCLC and 37 were mixed SCLC/NSCLC histology. Median survivals were 21 months versus 31 months for SBRT and surgery patients respectively (P = .07). There were no treatment-related mortalities. Mean length of hospital stay for surgical patients was 5.4 ± 5.7 days. Survival was longer in lymph node-negative surgery patients (median 48 months node-negative versus 19 months node-positive, P = .04). For node-negative-surgery patients, the estimated 2- and 5-year survival rates are 60% and 48%.

CONCLUSIONS

Our single-institutional experience over 25 years demonstrates that local treatment with surgery or SBRT for clinical stage I SCLC is safe and effective, with survivals lower than similar stage non-small-cell carcinoma patients. However, our results compare favorably with prior small-cell surgical series and far better than reported results of chemoradiotherapy for similar stage patients, thereby validating current recommendations for employing surgery or SBRT for stage I SCLC.

Dysfunction of CD8+ T cells around tumor cells leads to occult lymph node metastasis in NSCLC patients

Occult lymph node metastasis (OLNM) is one of the main causes of regional recurrence in inoperable N0 non-small cell lung cancer (NSCLC) patients following stereotactic ablation body radiotherapy (SABR) treatment. The integration of immunotherapy and SABR (I-SABR) has shown preliminary efficiency in mitigating this recurrence. Therefore, it is necessary to explore the functional dynamics of critical immune effectors, particularly CD8+ T cells in the development of OLNM. In this study, tissue microarrays (TMAs) and multiplex immunofluorescence (mIF) were used to identify CD8+ T cells and functional subsets (cytotoxic CD8+ T cells/predysfunctional CD8+ T cells (CD8+ Tpredys)/dysfunctional CD8+ T cells (CD8+ Tdys)/other CD8+ T cells) among the no lymph node metastasis, OLNM, and clinically evident lymph node metastasis (CLNM) groups. As the degree of lymph node metastasis escalated, the density of total CD8+ T cells and CD8+ Tdys cells, as well as their proximity to tumor cells, increased progressively and remarkably in the invasive margin (IM). In the tumor center (TC), both the density and proximity of CD8+ Tpredys cells to tumor cells notably decreased in the OLNM group compared with the group without metastasis. Furthermore, positive correlations were found between the dysfunction of CD8+ T cells and HIF-1α+CD8 and cancer microvessels (CMVs). In conclusion, the deterioration in CD8+ T cell function and interactive dynamics between CD8+ T cells and tumor cells play a vital role in the development of OLNM in NSCLC. Strategies aimed at improving hypoxia or targeting CMVs could potentially enhance the efficacy of I-SABR.

The optimal treatment for patients with stage I non-small cell lung cancer: minimally invasive lobectomy versus stereotactic ablative radiotherapy - a nationwide cohort study

OBJECTIVES

The aim of the Early-Stage LUNG cancer (ESLUNG) study was to compare outcomes after minimally invasive lobectomy (MIL) and stereotactic ablative radiotherapy (SABR) in patients with stage I non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

In this retrospective cohort study, patients with clinical stage I NSCLC (according to TNM7), treated in 2014-2016 with MIL or SABR, were included. 5-year overall survival (OS) and recurrence-free survival (RFS) were calculated and compared between patients treated with MIL and a propensity score (PS)-weighted SABR population with characteristics comparable to those of the MIL group.

RESULTS

1211 MIL and 972 SABR patients were included. Nodal upstaging occurred in 13.0 % of operated patients. 30-day mortality was 1.0 % after MIL and 0.2 % after SABR. After SABR, the 5-year regional recurrence rate (18.1 versus 14.2 %; HR 0.74, 95 % CI 0.58-0.94) and distant metastasis rate (26.2 versus 20.2 %; HR 0.72, 95 % CI 0.59-0.88) were significantly higher than after MIL, with similar local recurrence rate (13.1 versus 12.1 %; HR 0.90, 95 % CI 0.68-1.19). Unadjusted 5-year OS and RFS were 70.2 versus 40.3 % and 58.0 versus 25.1 % after MIL and SABR, respectively. PS-weighted, multivariable analyses showed no significant difference in OS (HR 0.89, 95 % CI 0.65-1.20) and better RFS after MIL (HR 0.70, 95 % CI 0.49-0.99).

CONCLUSION

OS was not significantly different between stage I NSCLC patients treated with MIL and the PS-weighted population of patients treated with SABR. For operable patients with stage I NSCLC, SABR could therefore be an alternative treatment option with comparable OS outcome. However, RFS was better after MIL due to fewer regional recurrences and distant metastases. Future studies should focus on optimization of patient selection for MIL or SABR to further reduce postoperative mortality and morbidity after MIL and nodal failures after SABR.

[Prevention, Diagnosis, Therapy, and Follow-up of Lung Cancer - Interdisciplinary Guideline of the German Respiratory Society and the German Cancer Society - Abridged Version]

The current S3 Lung Cancer Guidelines are edited with fundamental changes to the previous edition based on the dynamic influx of information to this field:The recommendations include de novo a mandatory case presentation for all patients with lung cancer in a multidisciplinary tumor board before initiation of treatment, furthermore CT-Screening for asymptomatic patients at risk (after federal approval), recommendations for incidental lung nodule management , molecular testing of all NSCLC independent of subtypes, EGFR-mutations in resectable early stage lung cancer in relapsed or recurrent disease, adjuvant TKI-therapy in the presence of common EGFR-mutations, adjuvant consolidation treatment with checkpoint inhibitors in resected lung cancer with PD-L1 ≥ 50%, obligatory evaluation of PD-L1-status, consolidation treatment with checkpoint inhibition after radiochemotherapy in patients with PD-L1-pos. tumor, adjuvant consolidation treatment with checkpoint inhibition in patients withPD-L1 ≥ 50% stage IIIA and treatment options in PD-L1 ≥ 50% tumors independent of PD-L1status and targeted therapy and treatment option immune chemotherapy in first line SCLC patients.Based on the current dynamic status of information in this field and the turnaround time required to implement new options, a transformation to a "living guideline" was proposed.

Occult lymph node metastasis is not a favorable factor for resected NSCLC patients

BACKGROUND

This study was to compare the clinical presentations and survivals between the non-small cell lung cancer (NSCLC) patients with occult lymph node metastasis (OLNM) and those with evident lymph node metastasis (ELNM). We also intended to analyze the predictive factors for OLNM.

METHODS

Kaplan-Meier method with log-rank test was used to compare survivals between groups. Propensity score matching (PSM) was used to reduce bias. The least absolute shrinkage and selection operator (LASSO)-penalized Cox multivariable analysis was used to identify the prognostic factors. Random forest was used to determine the predictive factors for OLNM.

RESULTS

A total of 2,067 eligible cases (N0: 1,497 cases; occult N1: 165 cases; evident N1: 54 cases; occult N2: 243 cases; evident N2: 108 cases) were included. The rate of OLNM was 21.4%. Patients with OLNM were tend to be female, non-smoker, adenocarcinoma and had smaller-sized tumors when compared with the patients with ELNM. Survival curves showed that the survivals of the patients with OLNM were similar to those of the patients with ELNM both before and after PSM. Multivariable Cox analysis suggested that positive lymph nodes (PLN) was the only prognostic factor for the patients with OLNM. Random forest showed that clinical tumor size was an important predictive factor for OLNM.

CONCLUSIONS

OLNM was not rare. OLNM was not a favorable sign for resected NSCLC patients with lymph node metastasis. PLN determined the survivals of the patients with OLNM. Clinical tumor size was a strong predictive factor for OLNM.

Local control and survival after stereotactic body radiation therapy of early-stage lung cancer patients in Slovenia

BACKGROUND

Stereotactic body radiation therapy (SBRT) precisely and non-invasively delivers ablative radiation dose to tumors in early-stage lung cancer patients who are not candidates for surgery or refuse it. The aim of research was to evaluate local control, overall survival (OS), local progression free survival (LPFS), distant metastases free survival (DMFS), disease free survival (DFS) and toxicity in early-stage lung cancer patients treated with SBRT in a single tertiary cancer centre.

PATIENTS AND METHODS

We retrospectively evaluated medical records and radiation treatment plan parameters of 228 tumors irradiated in 206 early-stage lung cancer patients between 2016 and 2021 at the Institute of Oncology Ljubljana.

RESULTS

After 25 months of median follow up, 68 of 206 (33%) patients died. Median OS was 46 months (CI 36-56), 1-year, 2-year and 3-year OS were 87%, 74% and 62% and 5-year OS was 31%. A total of 45 disease progressions have been identified in 41 patients. Local progress only was noticed in 5 (2%) patients, systemic progress in 32 (16%) and combined systemic and local in 4 (2%) patients. Local control rate (LCR) at 1 year was 98%, at 2 and 3 years 96% and 95% at 5 years. The 1-, 2- and 3-year LPFS were 98%, 96% and 94%, respectively and 5-year LPFS was 82%. One, 2-, 3- and 5-year DFS were 89%, 81%, 72% and 49%, respectively. Among 28 toxicities recorded only one was Grade 4 (pneumonitis), all others were Grade 1 or 2. No differences in LCR, LPFS, DFS were found in univariate analysis comparing patient, tumor, and treatment characteristics. For OS the only statistically significant difference was found in patients with more than 3 comorbidities compared to those with less comorbidities.

CONCLUSIONS

Early lung cancer treated with SBRT at single tertiary cancer centre showed that LCR, LPFS, DFS, DMFS and OS were comparable to published studies. Patients with many comorbidities had significantly worse overall survival compared to those with less comorbidities. No other significant differences by patient, tumor, or treatment characteristics were found for DMFS, LPFS, and DFS. Toxicity data confirmed that treatment was well tolerated.

Percutaneous image-guided thermal ablation of lung cancer: What is the evidence?

Thermal ablation techniques have now been used for more than twenty years in the treatment of primary lung tumours, predominantly non-small cell lung cancer (NSCLC). Although primarily used for the treatment of early-stage disease in non-surgical patients, thermal ablation is now also being used in selected patients with oligometastatic and oligoprogressive disease. This review discusses the techniques available for thermal ablation, the evidence for use of thermal ablation in primary lung tumours in early- and advanced-stage disease and compares thermal ablation to alternative treatment strategies.

High-dose stereotactic body radiotherapy using CyberKnife® for stage I peripheral lung cancer: a single-center retrospective study

Background

This retrospective study was performed to evaluate the efficacy and toxicity of high-dose stereotactic body radiotherapy (SBRT) using a CyberKnife® for patients with stage I peripheral non-small cell lung cancer (NSCLC).

Methods

Ninety-six patients with stage I peripheral NSCLC who were treated with SBRT using a CyberKnife® from August 2010 to June 2019 were identified and included in this study. Local control (LC), local progression-free survival (LPFS), progression-free survival (PFS), overall survival (OS), and late toxicity were evaluated. Potential risk factors associated with LC, LPFS, PFS, or OS were investigated by univariate analyses.

Results

Data of 96 patients were examined. The prescribed dose to the tumor was 54 Gy in 3 fractions in 91 patients and 60 Gy in 3 fractions in 5 patients. The median follow-up duration was 27 months. The 2-year LC, LPFS, PFS, and OS rates were 97%, 88%, 84%, and 90%, respectively. The T factor was significantly correlated with LC, LPFS, and PFS. The 2-year LC rate for patients with T1a/T1b and T1c/T2a disease was 100% and 90%, respectively (p < 0.05), and the 2-year PFS rate for the corresponding patients was 95% and 65%, respectively (p < 0.001). One patient (1%) developed grade 3 radiation pneumonitis.

Conclusions

High-dose SBRT using a CyberKnife® for stage I peripheral NSCLC produced favorable treatment outcomes with acceptable late toxicity. Further studies are needed to improve the treatment outcomes for patients with T1c/T2a disease.

A Propensity-Matched Analysis of Survival of Clinically Diagnosed Early-Stage Lung Cancer and Biopsy-Proven Early-Stage Non-Small Cell Lung Cancer Following Stereotactic Ablative Radiotherapy

Purpose

Stereotactic body radiotherapy (SBRT) has been increasingly regarded as a reasonable option for early-stage lung cancer patients without pretreatment pathologic results, but the efficacy and safety in a Chinese population remains unclear. The aim of this study was to compare survival outcomes and toxicities between patients with clinically diagnosed early-stage lung cancer or biopsy-proven early-stage non-small cell lung cancer and to demonstrate the rationality of this treatment.

Material and Methods

From May 2012 to December 2018, 56 patients with clinically diagnosed early-stage lung cancer and 60 patients with early-stage biopsy-proven were selected into non-pathological group and pathological group, respectively. Propensity score matching (PSM) was performed to reduce patient selection bias. Survival analysis with log-rank test was used to assess the differences of treatment outcomes, which included local control (LC), progression-free survival (PFS), and overall survival (OS).

Results

The median age was 76 (range 47–93) years, and the median follow-up time was 58.3 (range 4.3–95.1) months in the cohort without pathologic results. The median age was 74 (range 57–88) years, and the median follow-up time was 56.3 (range 2.6–94) months in the cohort with pathologic results. 45 matched-pair were analyzed. The 5-year LC, PFS, and OS rates in matched-pair patients with or without pathologic biopsy were 85.5% and 89.8%, 40.6% and 70.9%, and 63.2% and 76.1%, respectively. On Kaplan-Meier survival analysis after PSM analysis, there was no significant difference between patients with pathologic results versus patients with no pathologic results in terms of LC (P= 0.498) and OS (P=0.141). Of the matched-pair patients treated with SBRT, only 1 patient experienced grade 3 or above radiation pneumonitis.

Conclusion

For early-stage lung cancer patients with medically inoperable or not suitable for invasive diagnosis, SBRT may be a good local treatment.

Use and Outcomes of SBRT for Early Stage NSCLC Without Pathologic Confirmation in the Veterans Health Care Administration

Purpose

Stereotactic body radiation therapy (SBRT) use has increased among patients without pathologic confirmation (PC) of lung cancer. Empirical SBRT without PC raises concerns about variation in workup and patient selection, but national trends have not been well described. In this study, we assessed patterns of empirical SBRT use, workup, and causes of death among a large national non-small cell lung cancer (NSCLC) cohort.

Methods and Materials

We identified 2221 patients treated with SBRT for cT1-T2aN0M0 NSCLC in the Veterans Affairs health care system from 2008 to 2015. We reviewed their pretreatment workup and assessed associations between absence of PC and clinical and demographic factors. We compared causes of death between PC and non-PC groups and used Cox proportional hazards modeling to compare overall survival and lung cancer specific survival (LCSS) between these groups.

Results

Treatment without PC varied from 0% to 61% among Veterans Affairs medical centers, with at least 5 cases of stage I NSCLC. Overall, 14.9% of patients were treated without PC and 8.8% did not have a biopsy attempt. Ten percent of facilities were responsible for almost two-thirds (62%) of cases of treatment without PC. Of non-PC patients, 95.5% had positron emission tomography scans, 40.6% had biopsy procedures attempted, and 12.7% underwent endobronchial ultrasound. Non-PC patients were more likely to have cT1 tumors and live outside the histoplasmosis belt. Age, sex, smoking status, and Charlson comorbidity index were similar between groups. Lung cancer was the most common cause of death in both groups. Overall survival was similar between groups, whereas non-PC patients had better LCSS (hazard ratio = 0.77, P = .031).

Conclusions

Empirical SBRT use varied widely among institutions and appropriate radiographic workup was consistently used in this national cohort. Future studies should investigate determinants of variation and reasons for higher LCSS among non-PC patients.

Stage I non-small cell lung cancer: Treatment modalities, Dutch daily practice and future perspectives

OBJECTIVES

Several treatment modalities are available for patients with stage I non-small cell lung cancer (NSCLC). Over the past decade, these treatment modalities have been further investigated and might have changed current treatment regimens. In this review we present an overview of the treatment options, developments and future perspectives for stage I NSCLC. Furthermore, we describe the current use of these treatment modalities in the Netherlands.

MATERIALS AND METHODS

A bibliographical search was performed in PubMed and the Cochrane Library for publications concerning treatment modalities for stage I NSCLC. In addition, evidence-based guidelines of the European Society for Medical Oncology (ESMO) and the National Comprehensive Cancer Network (NCCN) were studied.

RESULTS

The guideline-recommended treatment for operable stage I NSCLC patients is a lobectomy with systematic lymph node dissection. Inoperable patients or those refusing surgery are offered stereotactic ablative radiotherapy (SABR). Percutaneous ablation, such as radiofrequency ablation, is a non-surgical minimally invasive technique offered to those who are ineligible for surgery or SABR. The role of systemic therapy is currently limited. However, the efficacy of immunotherapy is being investigated in clinical trials. In the Netherlands, an increasing use of SABR and a relative decrease in resection rates have been observed.

CONCLUSION

Surgery and SABR are currently the prevailing treatment modalities for stage I NSCLC patients. Despite optimization of treatment regimens, survival of patients with stage I NSCLC remains to be improved. Future studies are required to optimize treatment strategies, but also to investigate factors influencing treatment decision-making for patients with stage I NSCLC.

Stereotactic radiotherapy for early stage non-small cell lung cancer: current standards and ongoing research

Stereotactic body radiation therapy (SBRT) allows for the non-invasive and precise delivery of ablative radiation dose. The use and availability of SBRT has increased rapidly over the past decades. SBRT has been proven to be a safe, effective and efficient treatment for early stage non-small cell lung cancer (NSCLC) and is presently considered the standard of care in the treatment of medically or functionally inoperable patients. Evidence from prospective randomized trials on the optimal treatment of patients deemed medically operable remains owing, as three trials comparing SBRT to surgery in this cohort were terminated prematurely due to poor accrual. Yet, SBRT in early stage NSCLC is associated with favorable toxicity profiles and excellent rates of local control, prompting discussion in regard of the treatment of medically operable patients, where the standard of care currently remains surgical resection. Although local control in early stage NSCLC after SBRT is high, distant failure remains an issue, prompting research interest to the combination of SBRT and systemic treatment. Evolving advances in SBRT technology further facilitate the safe treatment of patients with medically or anatomically challenging situations. In this review article, we discuss international guidelines and the current standard of care, ongoing clinical challenges and future directions from the clinical and technical point of view.

Trends and variations in treatment of stage I-III non-small cell lung cancer from 2008 to 2018: A nationwide population-based study from the Netherlands

INTRODUCTION

This Dutch population-based study describes nationwide treatment patterns and its variations for stage I-III non-small cell lung cancer (NSCLC).

MATERIALS AND METHODS

Patients diagnosed with clinical stage I-III NSCLC in the period 2008-2018 were selected from the Netherlands Cancer Registry. Treatment trends were studied over time and age groups. Use of radiotherapy versus surgery (stage I-II), and concurrent versus sequential chemoradiotherapy (stage III) were analyzed by logistic regression.

RESULTS

In stage I, the rate of surgery decreased from 58 % (2008) to 40 % (2018) while radiotherapy use increased over time (from 31 % to 52 %), which mostly concerned stereotactic body radiotherapy (74 %). In stage II, 54 % of patients received surgery, and use of radiotherapy alone increased from 18 % to 25 %. The strongest factors favoring radiotherapy over surgery were WHO performance status (OR ≥ 2 vs 0: 23.39 (95% CI: 18.93-28.90)), increasing age (OR ≥ 80 vs <60 years: 14.52 (95% CI: 13.02-16.18)) and stage (OR stage II vs I: 0.61 (95% CI: 0.57-0.65)). In stage III, the combined use of chemotherapy and radiotherapy increased from 35 % (2008) to 39 % (2018). In all years, 23 % received concurrent chemoradiotherapy, 9 % sequential chemoradiotherapy, 23 % radiotherapy or chemotherapy alone, and 25 % best supportive care. The strongest factors favoring concurrent over sequential chemoradiotherapy were age (OR ≥ 80 vs <60 years: 0.14 (95% CI: 0.10-0.19)), WHO Performance status (OR ≥ 2 vs 0: 0.33 (95% CI: 0.24-0.47)) and region (OR east vs north: 0.39 (95% CI: 0.30-0.50)).

CONCLUSIONS

The use of radiotherapy became more prominent over time in stage I NSCLC. Combined use of chemotherapy and radiotherapy marginally increased in stage III: only one third of patients received chemoradiotherapy, mainly concurrently. Treatment variation seen between patient groups suggests tailored treatment decision, while variation between hospitals and regions indicate differences in clinical practice.

Comparison of Oncologic Outcomes between Carbon Ion Radiotherapy and Stereotactic Body Radiotherapy for Early-Stage Non-Small Cell Lung Cancer

Simple Summary

Lung cancer is a leading cause of cancer-related death. Stereotactic body radiotherapy (SBRT) is the standard treatment for inoperable early-stage non-small cell lung cancer (NSCLC). Carbon ion radiotherapy (CIRT) is a safe and effective treatment for early-stage NSCLC. However, there is no direct comparison study between these treatments. The present study aimed to compare oncologic outcomes after CIRT and SBRT for early-stage NSCLC in a single-institutional and contemporaneous cohort. We demonstrated favorable overall survival and local control in the CIRT group compared to those in the SBRT group using log-rank tests and Cox regression analyses for 89 patients. In addition, these results were validated in propensity score-adjusted analyses. The present retrospective comparison study showed a positive efficacy profile of CIRT, which is beneficial in the management of early-stage NSCLC.

Abstract

Lung cancer is a leading cause of cancer-related deaths worldwide. Radiotherapy is an essential treatment modality for inoperable non-small cell lung cancer (NSCLC). Stereotactic body radiotherapy (SBRT) is the standard treatment for early-stage NSCLC because of its favorable local control (LC) compared to conventional radiotherapy. Carbon ion radiotherapy (CIRT) is a kind of external beam radiotherapy characterized by a steeper dose distribution and higher biological effectiveness. Several prospective studies have shown favorable outcomes. However, there is no direct comparison study between CIRT and SBRT to determine their benefits in the management of early-stage NSCLC. Thus, we conducted a retrospective, single-institutional, and contemporaneous comparison study, including propensity score-adjusted analyses, to clarify the differences in oncologic outcomes. The 3-year overall survival (OS) was 80.1% in CIRT and 71.6% in SBRT (p = 0.0077). The 3-year LC was 87.7% in the CIRT group and 79.1% in the SBRT group (p = 0.037). Multivariable analyses showed favorable OS and LC in the CIRT group (hazard risk [HR] = 0.41, p = 0.047; HR = 0.30, p = 0.040, respectively). Log-rank tests after propensity score matching and Cox regression analyses using propensity score confirmed these results. These data provided a positive efficacy profile of CIRT for early-stage NSCLC.

Occult lymph node metastases in clinical N0/N1 NSCLC; A single center in-depth analysis

OBJECTIVES

Lymph node staging in patients with non-small cell lung cancer is crucial for determining prognosis and treatment. Our objective was to evaluate the clinical- to pathological agreement of guideline-concordant nodal staging in patients with resectable NSCLC and assess occurrence and distribution of occult lymph node metastases (OLM).

MATERIALS AND METHODS

In a retrospective single center cohort study (n = 390), we analyzed all surgically treated NSCLC patients from January 2015 until April 2019. Patients were classified into sub-groups (1) mediastinal staging by PET-CT/CT-scan (IMAGE-group) or (2) invasive staging by endobronchial ultrasound and mediastinoscopy (INVAS-group). Agreement between final clinical (cN) and pathological nodal stage (pN) and the presence and location of OLM are analyzed.

RESULTS

Agreement between cN- and pN-stage was 86.3 % in the IMAGE-group (n = 117) and 50.9 % in the INVAS-group (n = 167). Occult N1 disease was found in 33 patients (16.6 % in cN0) of which 52 % occurred in LN-regions 12-14. Occult N2 disease was found in 20 cases (6.5 % in cN0 and 12.7 % in cN1). Combined, 23.1 % of all pre-operatively cN0-staged patients (n = 46/199) had OLM (pN+), of which 12.1 % (24/199) had metastases in regions 5-6 and/or 12-14. Of all patients with OLM, 50.0 % (23/46) had primary tumors ≤30 mm.

CONCLUSION

OLM are frequently identified in clinically N0/N1 NSCLC, also in tumors <3 cm, and often in regions beyond reach of current staging techniques. These findings should be addressed when non-surgical treatment or sub-lobar resections are considered for early stage lung cancer.

Current status of immune checkpoint inhibition in early-stage NSCLC

Immune checkpoint inhibition (ICI) immunotherapy has revolutionized the approach to metastatic non-small-cell lung cancer (NSCLC). In particular, antibodies blocking the inhibitory immune checkpoints programmed death 1 (PD-1) and its ligand (PD-L1) are associated with higher response rates, improved overall survival and better tolerability as compared with conventional cytotoxic chemotherapy. Recently, ICI has moved from the second-line to the first-line setting for many patients with non-oncogene-addicted NSCLC, either alone or in combination with chemotherapy. The next logical step is to examine this therapy in patients with non-metastatic NSCLC to improve long-term overall survival and cure rates. For patients with unresectable stage III NSCLC, ICI with durvalumab after concurrent chemoradiotherapy has brought a major improvement in 2-year progression-free and overall survival, which holds promise for an improved cure rate. As the relapse pattern in patients with completely resected early-stage NSCLC is predominantly systemic, high expectations rest on the integration of ICI therapy in their treatment approach. A large number of studies with adjuvant or neo-adjuvant ICI are ongoing and will be discussed here. The advent of stereotactic ablative radiotherapy has brought a valid alternative treatment of patients unfit for or not willing to undergo surgery. Data on combining systemic therapy and stereotactic ablative radiotherapy are virtually non-existent, but there is a strong biological rationale to combine radiotherapy and ICI therapy. Early findings in small feasibility studies are promising and now need to be explored in well-designed phase III trials.

Oncologic Outcomes of Surgery Versus SBRT for Non-Small-Cell Lung Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

The optimal treatment of stage I non-small-cell lung carcinoma is subject to debate. The aim of this study was to compare overall survival and oncologic outcomes of lobar resection (LR), sublobar resection (SR), and stereotactic body radiotherapy (SBRT).

METHODS

A systematic review and meta-analysis of oncologic outcomes of propensity matched comparative and noncomparative cohort studies was performed. Outcomes of interest were overall survival and disease-free survival. The inverse variance method and the random-effects method for meta-analysis were utilized to assess the pooled estimates.

RESULTS

A total of 100 studies with patients treated for clinical stage I non-small-cell lung carcinoma were included. Long-term overall and disease-free survival after LR was superior over SBRT in all comparisons, and for most comparisons, SR was superior to SBRT. Noncomparative studies showed superior long-term overall and disease-free survival for both LR and SR over SBRT. Although the papers were heterogeneous and of low quality, results remained essentially the same throughout a large number of stratifications and sensitivity analyses.

CONCLUSION

Results of this systematic review and meta-analysis showed that LR has superior outcomes compared to SBRT for cI non-small-cell lung carcinoma. New trials are underway evaluating long-term results of SBRT in potentially operable patients.

The role of surgery for stage I non-small cell lung cancer in octogenarians in the era of stereotactic body radiotherapy in the Netherlands

OBJECTIVES

Resection is the standard treatment for stage I non-small cell lung cancer (NSCLC) in operable patients. Stereotactic body radiotherapy (SBRT) is recommended for inoperable patients. A shift from surgery to SBRT is expected in elderly patients due to increased frailty and competing risks. We assessed the current influence of age on treatment decision-making and overall survival (OS).

MATERIALS AND METHODS

We performed a retrospective cohort study using data from patients with clinical stage I NSCLC diagnosed in 2012-2016 and treated with lobectomy, segmentectomy, wedge resection, or SBRT, retrieved from the Netherlands Cancer Registry. Patient characteristics and OS were compared between SBRT and (sub)lobar resection for patients aged 18-79 and ≥80 years.

RESULTS AND CONCLUSION

8764 patients treated with lobectomy (n = 4648), segmentectomy (n = 122), wedge resection (n = 272), or SBRT (n = 3722) were included. In 2012-2016, SBRT was increasingly used for octogenarians and younger patients from 75.3% to 83.7% and from 30.8% to 43.2%, respectively. Five-year OS in the whole population was 70% after surgery versus 39% after SBRT and 50% versus 27% in octogenarians. After correction for age, gender, year of diagnosis, and clinical T-stage, OS was equal after lobectomy and SBRT in the first 2 years after diagnosis. However, after >2 years, OS was better after lobectomy than after SBRT. SBRT is the prevailing treatment in octogenarians with stage I NSCLC. While surgery is associated with better OS than SBRT, factors other than treatment modality (e.g. comorbidity) may have had a significant impact on survival. The wider application of SBRT in octogenarians likely reflects the frailty of this group. Registries and trials are required to identify key determinants of frailty in this specific population to improve patient selection for surgery or SBRT.

Stereotactic Image Guided Lung Radiation Therapy for Clinical Early Stage Non-Small Cell Lung Cancer: A Long-Term Report From a Multi-Institutional Database of Patients Treated With or Without a Pathologic Diagnosis

PURPOSE

Early stage lung cancer is treated with stereotactic body radiation therapy (SBRT) in patients who are unable or unwilling to undergo surgical resection. Some patients' comorbidities are so severe that they are unable to even undergo a biopsy. A clinical diagnosis without biopsy before SBRT has been used, but there are limited data on its efficacy.

METHODS AND MATERIALS

Data on patients treated with SBRT for non-small cell lung cancer, with and without tissue confirmation, were collected from multiple institutions across Europe, Canada, and the United States. Patients with a minimum of 2 years of comprehensive follow up were selected for analysis. Treatment and patient characteristics were compared. Overall survival (OS), disease-free survival (DFS), cause-specific survival (CSS), and rates of local recurrence (LR), regional recurrence (RR), and distant metastasis (DM) were calculated and analyzed.

RESULTS

A total of 701 patients were identified, of which 67% had tissue confirmation of their tumors. The 3- and 5-year outcomes for OS, CSS, and DFS were 83.8%, 93.1%, 69%, and 60.6%, 86.7%, 45.5%, respectively. The rates for LR, RR, and DM at 3 and 5 years were 6.4%, 9.3%, 14.3%, and 10.5%, 14.3%, 19.7%, respectively. There were no statistically significant differences in survival outcomes or recurrences between the biopsy and no-biopsy cohorts.

CONCLUSIONS

SBRT for clinically diagnosed lung cancers is efficacious in appropriately selected patients, with similar outcomes as those with a pathologic diagnosis. Thorough clinical and radiographic evaluations in a multidisciplinary setting are critical to the management of these patients.