Adjuvant chemotherapy for high-risk pathological stage I non-small cell lung cancer

Perioperative Immunotherapy for Node-Negative Non-Small Cell Lung Cancer-Current Evidence and Future Directions

Neoadjuvant immunotherapy has gone from an idea to an indication in locally advanced lung cancer. Several phase III trials have demonstrated the superiority of neoadjuvant chemoimmunotherapy compared with chemotherapy in this setting. Although such progress has revolutionized the treatment of locally advanced disease, the unmet needs of stage I and stage II patients without lymph node disease have largely been underrepresented in existing trials. Up-front resection with few patients going on to complete adjuvant therapy remains the norm for most stage I and II patients. Emerging evidence now supports the exploration of supplemental checkpoint blockade in well-selected early-stage, node-negative patients with large tumors and no actionable driver mutations. Although concerns surrounding safety and risk exist, patient selection could be substantially improved using novel biomarker approaches that leverage our understanding of the tumor immune microenvironment of lung cancer. This review provides a comprehensive overview of the opportunities and controversies of perioperative immunotherapy in node-negative lung cancer.

Who benefit from adjuvant chemotherapy in stage I lung adenocarcinoma? A multi-dimensional model for candidate selection

BACKGROUND

Despite promising overall survival of stage I lung adenocarcinoma (LUAD) patients, 10-25 % of them still went through recurrence after surgery. [1] While it is still disputable whether adjuvant chemotherapy is necessary for stage I patients. [2] IASLC grading system for non-mucinous LUAD shows that minor high-grade patterns are significant indicator of poor prognosis. [3] Other risk factors, such as, pleura invasion, lympho-vascular invasion, STAS, etc. are also related to poor prognosis. [4-6] There still lack evidence whether IASLC grade itself or together with other risk factors can guide the use of adjuvant therapy in stage I patients. In this article, we tried to establish a multi-variable recurrence prediction model for stage I LUAD patients that is able to identify candidates of adjuvant chemotherapy.

METHODS

We retrospectively collected patients who underwent lung surgery from 2018.8.1 to 2018.12.31 at our institution and diagnosed with lung adenocarcinoma pT1-2aN0M0 (stage I). Clinical data, manifestation on CT scan, pathologic features, driver gene mutations and follow-up information were collected. Cox proportional hazards regression analyses were performed utilizing the non-adjuvant cohort to predict disease free survival (DFS) and a nomogram was constructed and applied to the total cohort. Kaplan-Meier method was used to compare DFS between groups. Statistical analysis was conducted by R version 3.6.3.

FINDINGS

A total of 913 stage I LUAD patients were included in this study. Median follow-up time is 48.1 months.4-year and 5-year DFS are 92.9 % and 89.6 % for the total cohort. 65 patient experienced recurrence or death. 4-year DFS are 97.0 %,94.6 % and 76.2 %, and 5-year DFS are 95.5 %, 90.0 % and 74.1 % in IASLC Grade1, 2 and 3, respectively(p < 0.0001). High-risk patients defined by single risk factors, such as, IASLC grade 3, pleura invasion, STAS, less LN resected could not benefit from adjuvant therapy. A LASSO-COX regression model was built and patients are divided into high-risk and low-risk groups. In the high-risk group, patients underwent adjuvant chemotherapy have longer DFS than those who did not (p = 0.024), while in the low-risk group, patients underwent adjuvant chemotherapy have inferior DFS than those who did not (p < 0.001).

INTERPRETATION

IASLC grading is a significant indicator of DFS, however it could not guide adjuvant therapy in our stage I LUAD cohort. Growth patterns and T indicators together with other risk factors could identify high-risk patients that are potential candidate of adjuvant therapy, including some stage IA LUAD patients.

Distinct impacts of radiological appearance on lymph node metastasis and prognosis based on solid size in clinical T1 non-small cell lung cancer

BACKGROUND

Solid nodules (SN) had more aggressive features and a poorer prognosis than part-solid nodules (PSN). This study aimed to evaluate the specific impacts of nodule radiological appearance (SN vs. PSN) on lymph node metastasis and prognosis based on solid size in cT1 non-small cell lung cancer (NSCLC).

METHODS

Patients with cT1 NSCLC who underwent anatomical resection between 2010 and 2019 were retrospectively screened. Univariable and multivariable logistic regression analyses were adopted to evaluate the associations between nodule radiological appearance and lymph node metastasis. The log-rank test and Cox regression analyses were applied for prognostic evaluation. The cumulative recurrence risk was evaluated by the competing risk model.

RESULTS

There were 958 and 665 NSCLC patients with PSN and SN. Compared to the PSN group, the SN arm had a higher overall lymph node metastasis rate (21.7% vs. 2.7%, P < 0.001), including nodal metastasis at N1 stations (17.7% vs. 2.1%), N2 stations (14.0% vs. 1.6%), and skip nodal metastasis (3.9% vs. 0.6%). However, for cT1a NSCLC, no significant difference existed between SN and PSN (0 vs. 0.4%, P = 1). In addition, the impacts of nodule radiological appearance on lymph node metastasis varied between nodal stations. Solid NSCLC had an inferior prognosis than part-solid patients (5-year disease-free survival: 79.3% vs. 96.2%, P < 0.001). The survival inferiority only existed for cT1b and cT1c NSCLC, but not for cT1a. Strikingly, even for patients with nodal involvement, SN still had a poorer disease-free survival (P = 0.048) and a higher cumulative incidence of recurrence (P < 0.001) than PSN. Specifically, SN had a higher recurrence risk than PSN at each site. Nevertheless, the distribution of recurrences between SN and PSN was similar, except that N2 lymph node recurrences were more frequent in solid NSCLC (28.21% vs. 7.69%, P = 0.041).

CONCLUSION

SN had higher risks of lymph node metastasis and poorer prognosis than PSN for cT1b and cT1c NSCLC, but not for cT1a. SN exhibited a greater proportion of N2 lymph node recurrence than PSN. SN and PSN needed distinct strategies for nodal evaluation and postoperative follow-up.

Dynamic Analysis of the Impact of Micropapillary Component on Different Recurrence Patterns of Pathological Stage IA3 Lung Adenocarcinoma: A Multicenter, Retrospective Study

BACKGROUND

This study aimed to evaluate the dynamic impact of the micropapillary (MIP) component on local recurrence (LR), distant metastasis (DM), and multiple recurrence (MR) of pathological stage IA3 lung adenocarcinoma.

METHODS

Between July 2012 and July 2020, a total of 351 patients at two medical institutions were enrolled in this study. Cumulative incidence of curves, dynamic risk curves, and time-dependent multivariate analysis was performed to evaluate the effect of the MIP component on patients.

RESULTS

The 5-year cumulative incidence of total recurrence with or without an MIP component was 34.2% and 12.3%, respectively (p = 0.001). In three recurrence patterns, our findings revealed that the 5-year cumulative incidence of LR (p = 0.048) and DM (p = 0.005) was higher in the 'MIP-present' group than in the 'MIP-absent' group. In the dynamic recurrence curve, the risk of the three recurrence patterns was different and varied over time between the two groups, especially in DM. Moreover, the dynamic cumulative event curve showed that after 1, 2, and 3 years of survival, the cumulative incidence of DM in the group with MIP continued to be higher than that in the group without MIP (all p < 0.05). Time-dependent Cox regression analysis indicated that the MIP component continued to be an independent risk factor for the cumulative incidence of DM in patients with 3-year survival.

CONCLUSIONS

Of the three recurrence patterns, the MIP component mainly aggravated the risk of DM in patients with pathological stage IA3 lung adenocarcinoma, which persisted for 3 years.

Diagnosis, treatment, and prognosis of stage IB non-small cell lung cancer with visceral pleural invasion

With the increasing implementation of early lung cancer screening and the increasing emphasis on physical examinations, the early-stage lung cancer detection rate continues to rise. Visceral pleural invasion (VPI), which denotes the tumor's breach of the elastic layer or reaching the surface of the visceral pleura, stands as a pivotal factor that impacts the prognosis of patients with non-small cell lung cancer (NSCLC) and directly influences the pathological staging of early-stage cases. According to the latest 9th edition of the TNM staging system for NSCLC, even when the tumor diameter is less than 3 cm, the final T stage remains T2a if VPI is present. There is considerable controversy within the guidelines regarding treatment options for stage IB NSCLC, especially among patients exhibiting VPI. Moreover, the precise determination of VPI is important in guiding treatment selection and prognostic evaluation in individuals with NSCLC. This article aims to provide a comprehensive review of the current status and advancements in studies pertaining to stage IB NSCLC accompanied by VPI.

Prognostic Impact of Cancer Inflammation Prognostic Index for Non-small Cell Lung Cancer

PURPOSE

Cancer-inflammation prognostic index (CIPI) is calculated by multiplying the concentration of carcinoembryonic antigen by neutrophil-to-lymphocyte ratio. CIPI has been reported as a prognostic factor for colorectal cancer. Although carcinoembryonic antigen and neutrophil-to-lymphocyte ratio have been reported as prognostic factors for non-small cell lung cancer (NSCLC), it has not been investigated whether CIPI is a useful marker.

METHODS

We analyzed the prognostic factors, including CIPI, in 700 NSCLC patients treated by pulmonary resection. We also analyzed a subgroup of 482 patients with pathological stage I NSCLC.

RESULT

CIPI > 14.59 (P < 0.01), maximum standardized uptake value (SUVmax) > 5.35 (P < 0.01), lymphatic invasion (P = 0.01), and pathological stage (P < 0.01) were significant factors for relapse-free survival (RFS) in multivariate analysis. SUVmax > 5.35 (P < 0.01) and pathological stage (P < 0.01) were revealed as significant factors for overall survival in the multivariate analysis. In the subanalysis, CIPI > 14.88 (P = 0.01) and SUVmax > 5.07 (P < 0.01) were significant factors for RFS of pathological stage I NSCLC in multivariate analysis.

CONCLUSION

CIPI was a significant factor for RFS in NSCLC patients treated surgically, even in those with pathological stage I disease. SUVmax was also a significant factor for RFS and overall survival in NSCLC patients treated surgically, and for RFS in patients with pathological stage I NSCLC.

TRIAL REGISTRATION

The Institutional Review Board of Kanazawa Medical University approved the protocol of this retrospective study (Approval Number: I392), and written informed consent was obtained from all patients.

High-risk characteristics of pathological stage I lung adenocarcinoma after resection: patients for whom adjuvant chemotherapy should be performed

Background

The objective of the present study was to identify patients with pathologic stage I lung adenocarcinoma (LUAD) who are at high risk of recurrence and assess the efficacy of adjuvant chemotherapy (ACT) in these individuals.

Methods

A retrospective study was conducted on 1504 patients with pathologic stage I LUAD who underwent surgical resection at Shanghai Pulmonary Hospital and Sun Yat-sen University Cancer Center. Cox proportional hazard regression analyses were performed to identify indicators associated with a high risk of recurrence, while the Kaplan-Meier method and Log-rank test were employed to compare recurrence-free survival (RFS) and overall survival (OS) between patients with ACT and those without it.

Results

Four independent indicators, including age (≥62 years), visceral pleural invasion (VPI), predominant pattern (micropapillary/solid), and lymphovascular invasion (LVI), were identified to be significantly related with RFS. Subsequently, patients were classified into high-risk and low-risk groups by LVI, VPI, and predominant pattern. The administration of ACT significantly increased both RFS (P < 0.001) and OS (P = 0.03) in the high-risk group (n = 250). Conversely, no significant difference was observed in either RFS (P = 0.45) or OS (P = 0.063) between ACT and non-ACT patients in the low-risk group (n = 1254).

Conclusions

Postoperative patients with stage I LUAD with factors such as LVI, VPI, and micropapillary/solid predominant pattern may benefit from ACT.

The possibility of mutations of RAS signaling genes and/or TP53 in combination as a negative prognostic impact on pathological stage I non-small cell lung cancer

BACKGROUND

The recurrence rate of non-small cell lung cancer (NSCLC) is as high as 30%, even in the cancer with pathological stage I disease. Therefore, identifying factors predictive of high-risk pathological recurrence is important. However, few studies have examined the genetic status of these tumors and its relationship to prognosis.

MATERIALS AND METHODS

A cohort of 328 cases of primary lung cancer that underwent complete resection at Tokyo Medical and Dental University (TMDU) was screened for 440 cancer-associated genes using panel testing. Further analyses included 92 cases of pathological stage I NSCLC who did not receive adjuvant chemotherapy. Ridge regression was performed to identify association studies mutational status and postoperative recurrence. These data were then validated using clinical and genetic data from 56 patients in The Cancer Genome Atlas (TCGA).

RESULTS

Mutations in TP53, RAS signaling genes KRAS and HRAS, and EGFR were recurrently detected. Ridge regression analysis relevant to recurrence, as well as survival analysis, performed using data from the TMDU cohort revealed significantly shorter relapse-free survival (RFS) for patients with RAS signaling or TP53 gene mutations than for those without (log-rank test, p = 0.00090). This statistical trend was also suggested in the TCGA cohort (log-rank test, p = 0.10).

CONCLUSION

Mutations in RAS signaling genes and/or TP53 could be useful for the prediction of shorter RFS of patients with stage I NSCLC.

Correlations between iodine uptake, invasive CT features and pleural invasion in adenocarcinomas with pleural contact

Pleural contact in lung cancers does not always imply pleural invasion (PI). This study was designed to determine whether specific invasive CT characteristics or iodine uptake can aid in the prediction of PI. The sample population comprised patients with resected solid lung adenocarcinomas between April 2019 and May 2022. All participants underwent a contrast enhanced spectral CT scan. Two proficient radiologists independently evaluated the CT features and iodine uptake. Logistic regression analyses were employed to identify predictors for PI, via CT features and iodine uptake. To validate the improved diagnostic efficiency, accuracy analysis and ROC curves were subsequently used. A two-tailed P value of less than 0.05 was considered statistically significant. We enrolled 97 consecutive patients (mean age, 61.8 years ± 10; 48 females) in our study. The binomial logistic regression model revealed that a contact length > 10 mm (OR 4.80, 95% CI 1.92, 11.99, p = 0.001), and spiculation sign (OR 2.71, 95% CI 1.08, 6.79, p = 0.033) were independent predictors of PI, while iodine uptake was not. Enhanced sensitivity (90%) and a greater area under the curve (0.73) were achieved by integrating the two aforementioned CT features in predicting PI. We concluded that the combination of contact length > 10 mm and spiculation sign can enhance the diagnostic performance of PI.

The American Association for Thoracic Surgery (AATS) 2023 Expert Consensus Document: Staging and multidisciplinary management of patients with early-stage non-small cell lung cancer

Novel targeted therapy and immunotherapy drugs have recently been approved for use in patients with surgically resectable lung cancer. Accurate staging, early molecular testing, and knowledge of recent trials are critical to optimize oncologic outcomes in these patients.

Effects of pre-operative biopsy on recurrence and survival in stage I lung adenocarcinoma patients in China

Background

Whether pre-operative biopsy affects post-operative recurrence and metastasis of lung cancer patients is still controversial.

Methods

In order to clarify these disputes, we collected relevant literature to conduct a meta-analysis. To validate the results of the meta-analysis, we retrospectively analysed 575 patients with stage I lung adenocarcinoma who underwent surgical resection at our centre from 2010 to 2018 using propensity score matching and competing risk models.

Results

5509 lung cancer patients from 11 articles were included in the meta-analysis. Summary analysis showed that the total recurrence rate of the biopsy group was higher than that of the nonbiopsy group (risk ratio 1.690, 95% CI 1.220-2.330; p=0.001). After propensity score matching, we found that there was no significant correlation between biopsy and total recurrence (risk ratio 1.070, 95% CI 0.540-2.120; p=0.850). In our cohort, of 575 stage I lung adenocarcinomas, 113 (19.7%) patients underwent pre-operative biopsy. During a median (interquartile range) follow-up of 71 (57-93) months, multivariable analyses showed pre-operative biopsy in the overall observation cohort (subdistribution hazard ratio (SHR) 1.522, 95% CI 0.997-2.320; p=0.051) and in the propensity score-matched cohort (SHR 1.134, 95% CI 0.709-1.810; p=0.600) was not significantly correlated with the risk of recurrence and metastasis. Moreover, the pre-operative biopsy did not affect disease-free survival (SHR 0.853, 95% CI 0.572-1.273; p=0.438) or overall survival (SHR 0.647, 95% CI 0.352-1.189; p=0.161).

Conclusion

Pre-operative biopsy might not increase the risk of recurrence and metastasis, suggesting that these procedures might be safe for patients with stage I lung adenocarcinoma whose diagnosis is difficult to determine before surgery.

Evaluation of recurrence risk for patients with stage I invasive lung adenocarcinoma manifesting as solid nodules based on 18F-FDG PET/CT, imaging signs, and clinicopathological features

BACKGROUND

Stage I lung adenocarcinoma is a heterogeneous group. Previous studies have shown the prognostic evaluation value of PET/CT in this cohort; however, few studies focused on stage I invasive adenocarcinoma manifesting as solid nodules. This study aimed to evaluate the recurrence risk for patients with stage I invasive lung adenocarcinoma manifesting as solid nodules based on ¹⁸F-FDG PET/CT, CT imaging signs, and clinicopathological parameters.

METHODS

We retrospectively enrolled 230 patients who underwent ¹⁸F-FDG PET/CT examination between January 2013 and July 2019. Metabolic parameters: maximum standard uptake value (SUVmax), mean standard uptake value, tumor metabolic volume (MTV), and total tumor glucose digestion were collected. Kaplan-Meier method was used to evaluate recurrence-free survival (RFS), and the multivariate Cox proportional hazards model was used to determine the independent risk factors associated with RFS. The time-dependent receiver operating characteristic curve (ROC) method was used to calculate the optimal cutoff value of metabolic parameters.

RESULTS

The 5-year RFS rate for all patients was 71.7%. Multivariate Cox analysis revealed that the International Association for the Study of Lung Cancer Pathology Committee (IASLC) pathologic grade 3 [Hazard ratio (HR), 3.96; 95% Confidence interval (CI), 1.11-14.09], the presence of cavity sign (HR 5.38; 95% CI 2.23-12.96), SUVmax (HR 1.23; 95% CI 1.13-1.33), and MTV (HR 1.05; 95% CI 1.01-1.08) were potential independent prognostic factors for RFS. Patients with IASLC grade 3, the presence of cavity sign, SUVmax > 3.9, or MTV > 5.4 cm³ were classified as high risk, while others were classified as low risk. There was a significant difference in RFS between the high-risk and low-risk groups (HR 6.04; 95% CI 2.17-16.82, P < 0.001), and the 5-year RFS rate was 94.1% for the low-risk group and 61.3% for the high-risk group.

CONCLUSIONS

We successfully evaluate the recurrence risk of patients with stage I invasive adenocarcinoma manifesting as solid nodules for the first time. The 5-year RFS rate in the high-risk group was significantly lower than in the low-risk group (61.3% vs. 94.1%). Our study may aid in optimizing therapeutic strategies and improving survival benefits for those patients.

Adjuvant EGFR-TKI therapy in resected EGFR-mutation positive non-small cell lung cancer: A real-world study

Background

Although several clinical studies have laid the foundation for the adjuvant application of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs), some questions remain unresolved. This real-world study aimed to address questions such as the effect of adjuvant chemotherapy prior to adjuvant EGFR-TKI therapy on survival outcomes, and the duration of adjuvant EGFR-TKI therapy, etc.

Methods

Between October 2005 and October 2020, 227 consecutive patients with non-small cell lung cancer (NSCLC) who underwent complete pulmonary resections were included in this retrospective study. Patients received postoperative adjuvant chemotherapy followed by EGFR-TKI or adjuvant EGFR-TKI monotherapy. The disease-free survival (DFS) and overall survival (OS) were evaluated.

Results

Of the total 227 patients, 55 (24.2%) patients underwent 3-4 cycles of chemotherapy prior to receiving adjuvant EGFR-TKI therapy. The 5-year DFS rate was 67.8%, while the 5-year OS rate was 76.4%. The stages were significantly associated with both DFS (P&lt;0.001) and OS (P&lt;0.001), while no significant differences were observed in the DFS (P=0.093) and OS (P=0.399) between the adjuvant chemotherapy followed by EGFR-TKI and adjuvant EGFR-TKI monotherapy groups. A longer duration of EGFR-TKI therapy was associated with better DFS (P&lt;0.001) and OS (P&lt;0.001) benefit. Additionally, pTNM stage and duration of EGFR-TKI therapy were considered independent prognostic factors for long-term survival (All P&lt;0.05).

Conclusions

This study supports the use of EGFR-TKI as a postoperative adjuvant treatment for patients with stage II-IIIA EGFR-mutation positive NSCLC. Additionally, patients with stage I who had pathological risk factors were also suitable for receiving adjuvant EGFR-TKI therapy. Postoperative EGFR-TKI based, chemotherapy-free adjuvant regimen may be a potential therapeutic option for patients with EGFR-mutation positive NSCLC.

Type of lymphadenectomy does not influence survival in pIa NSCLC patients who underwent VATS lobectomy: Results from the national VATS group database

INTRODUCTION

Stage Ia presents an optimal survival rate after surgical resection, but the type of lymphadenectomy to use in these patients is still debated. The aim of this study is evaluate if one type of lymphadenectomy adopted influences survival in patients who underwent VATS lobectomy for stage Ia NSCLC.

METHODS

Clinical and pathological data from pIa patients in the prospective VATS Italian nationwide registry were reviewed and analysed. Patients and tumour characteristics,type of lymphadenectomy (sampling or radical nodal dissection,MRLD), were collected and correlated to Overall Survival(OS) and Disease free Survival(DFS). The Kaplan-Meier product-limit method was used to estimate OS and DFS and the log-rank test was adopted to evaluate the differences between groups. A propensity match was performed to reduce bias due to the retrospective study design.

RESULTS

The final analysis was conducted on 2039 patients, 179 died during follow-up,recurrence rate was 13%. MRLD was performed in 1287(63.1%)patients. The univariable analysis identified as favourable prognostic factors for OS the female sex(p = 0.023), low ECOG-score(0.008),low SUVmax(p < 0.001), GGO appearance(p < 0.001), pT < 2 cm(p = 0.002) and low tumour grading(p = 0.002). The multivariable analysis confirmed as independent prognostic factors low ECOG-score(p = 0.012), low SUVmax(p < 0.001) and low tumour grading(p < 0.001). Analysing survival in patients with solid/sub-solid nodules and after propensity score matching for pTdimension and number of N2 resected lymphnodes, no OS differences were present comparing sampling vs MRLD.

CONCLUSION

Survival in pIa patients seems to be determined by patient and tumour characteristics such as performance status,grading and SUVmax. Type of lymphadnectomy did not seem to be correlated with OS in these patients.

Adjuvant chemotherapy can benefit the survival of stage I lung adenocarcinoma patients with tumour spread through air spaces after resection: Propensity-score matched analysis

Background

It is still unclear whether stage I lung adenocarcinoma patients with tumour spread through air spaces (STAS) can benefit from postoperative adjuvant chemotherapy (ACT) after lobectomy. This study investigated the effect of ACT on the postoperative survival of patients with stage I (STAS⁺) lung adenocarcinoma.

Methods

We retrospectively analysed the clinical data of stage I (STAS⁺) invasive lung adenocarcinoma patients who underwent lobectomy in the Department of Thoracic Surgery of our hospital from January 1, 2013 to January 1, 2016. Propensity score matching (PSM) was performed to group patients to investigate whether ACT could lead to better prognosis of patients.

Results

A total of 593 patients with stage I (STAS⁺) lung adenocarcinoma were enrolled. The study after PSM included 406 patients. Kaplan–Meier survival analysis showed the experimental group had a better 3-year recurrence-free survival (RFS) rate (p = 0.037) and the 5-year RFS rate (p = 0.022) than the control group. It also had higher 5-year overall survival (p = 0.017). The multivariate analysis by Cox proportional hazard regression model showed that stage I STAS⁺ lung adenocarcinoma patients with lymphatic vessel invasion (HR: 1.711, 95% CI: 1.052-2.784; p = 0.045), vascular invasion (HR: 5.014, 95% CI: 3.154-7.969; p < 0.001), and visceral pleural invasion (HR: 2.086, 95% CI: 1.162-3.743; p = 0.014), and without ACT (HR: 1.675, 95% CI: 1.043-2.689; p = 0.033) had a significant survival disadvantage.

Conclusion

ACT can boost the postoperative survival of patients with stage I (STAS⁺) lung adenocarcinoma.

Rationale for Combing Stereotactic Body Radiation Therapy with Immune Checkpoint Inhibitors in Medically Inoperable Early-Stage Non-Small Cell Lung Cancer

Simple Summary

The rate of recurrence remains high for lymph node negative early-stage non-small cell lung cancer that are over 2–3 cm in size following stereotactic body radiation therapy (SBRT). This is due to the increased incidence of out-of-field failures, which warrants the addition of systemic therapy. Immune checkpoint inhibitors (ICIs), a class of immunotherapy, may induce a strong distant therapeutic effect known as the “abscopal” effect. This makes them a very suitable class of drugs to be combined with SBRT when treating early lung cancer with high-risk features, such as larger tumor size. In this review, we discuss the rationale and evidence for doing so.

Abstract

Stereotactic body radiation therapy (SBRT) has been widely adopted as an alternative to lobar resection in medically inoperable patients with lymph-node negative (N0) early-stage (ES) non-small cell lung cancer (NSCLC). Excellent in-field local control has been consistently achieved with SBRT in ES NSCLC ≤ 3 cm in size. However, the out-of-field control following SBRT remains suboptimal. The rate of recurrence, especially distant recurrence remains high for larger tumors. Additional systemic therapy is warranted in N0 ES NSCLC that is larger in size. Radiation has been shown to have immunomodulatory effects on cancer, which is most prominent with higher fractional doses. Strong synergistic effects are observed when immune checkpoint inhibitors (ICIs) are combined with radiation doses in SBRT’s dose range. Unlike chemotherapy, ICIs can potentiate a strong systemic response outside of the irradiated field when combined with SBRT. Together with their less toxic nature, ICIs represent a very suitable class of systemic agents to be combined with SBRT when treating ES NSCLC with high-risk features, such as larger tumor size. In this review, we describe the rationale and emerging evidence, as well as ongoing investigations in this area.

The prognostic significance of tumor spread through air space in stage I lung adenocarcinoma

Aim

There are still patients of stage I lung adenocarcinoma (ADC) suffering from local or distant recurrence. Herein we conducted a meta‐analysis to investigate the prognostic value of tumor spread through air space (STAS), a new form of invasion pattern, in patients with pathologically confirmed stage I lung ADC.

Methods

Related literature was searched using PubMed, Embase, Cochrane Library, and Web of Science databases from the inception dates to September 4, 2021. Recurrence‐free survival (RFS) and overall survival (OS) were set as primary outcome endpoints. In addition, subgroup analyses on operation mode, edition of the American Joint Committee on Cancer TNM staging, sample size, and research regions were also investigated.

Results

A total of 17 studies involving 9785 patients were included. The presence of STAS was detected in 31.2% of patients and was associated with poor RFS (adjusted hazard ratio [HR] = 1.93, p < 0.001) and OS (HR = 2.02, p < 0.001). In subgroup analysis on operation mode, the prognostic value of STAS was prominently shown in patients who underwent limited resection (RFS: HR = 3.58, p < 0.001; OS: HR = 3.37, p < 0.001), while for patients who underwent lobectomy, adverse impact of STAS on RFS was observed (HR = 1.60, p = 0.019), but no significant difference was observed on OS (HR = 1.56, p = 0.061). The results fluctuated in different regions while other factors did not alter the independent predictive value of STAS.

Conclusion

Tumor STAS should be considered as an adverse prognostic indicator for patients with stage I lung ADC, especially for those under limited resection. More intensive medical care for those patients needs to be investigated in further studies.