Adjuvant therapy for resected EGFR-mutant non-small-cell lung cancer

Opportunities and challenges of neoadjuvant targeted therapy in nonsmall cell lung cancer

PURPOSE OF REVIEW

The aim of this study is to summarize the completed and ongoing clinical trials of neoadjuvant targeted therapy, discuss tolerability and efficacy, and explain the role of neoadjuvant targeted therapy in patients with resectable nonsmall cell lung cancer (NSCLC). At the same time, the existing challenges are presented, including assessment methods, biomarkers, surrogate endpoints and so on. We also put forward our views on possible ways to make improvements and establish neoadjuvant therapy a standard treatment in resectable NSCLC.

RECENT FINDINGS

The mortality of lung cancer has decreased in the last 10 years, which can partly be attributed to advancement of targeted therapy. Targeted therapy has become the first-line treatment for patients with advanced mutation gene positive NSCLC, achieving the effect of prolonging overall survival (OS). Compared with chemotherapy, targeted therapy is associated with good tolerability and high response rate. Neoadjuvant targeted therapy has emerged in recent years and attracted attention of researchers. Early findings proved that neoadjuvant targeted therapy alone can improve patients' disease-free survival (DFS) and the efficacy of combining with other forms of neoadjuvant therapy is also being explored by researchers.

SUMMARY

Neoadjuvant targeted therapy is playing an important role in NSCLC and worth more in-depth research.

Patterns and risks of postoperative recurrence in completely resected EGFR-mutant non-small cell lung cancer: prognostic significance of routine immunohistochemical markers

Background

Recent studies indicate that EGFR-mutant non-small cell lung cancer (NSCLC) is a heterogeneous disease with varying prognosis. In order to design an optimized surveillance strategy and identify potential candidates for adjuvant therapy, the patterns and risks of postoperative recurrence in completely resected EGFR-mutant NSCLC should be investigated, which are currently largely unknown.

Methods

Consecutive patients with curatively resected EGFR-positive NSCLC receiving standard adjuvant chemotherapy without EGFR tyrosine kinase inhibitors (TKI), with or without adjuvant radiotherapy, from January 2007 to December 2017 in our cancer center, were retrospectively reviewed. Prognostic significance of ten routine immunohistochemical (IHC) markers were examined.

Results

After a median follow-up of 32 (range, 5-122) months, disease recurrence occurred in 197 (37.1%) of the 531 enrolled patients. The frequencies of thoracic recurrence, brain recurrence, bone recurrence, abdominal recurrence and neck recurrence, were 69.0%, 20.8%, 20.8%, 7.1% and 6.6%, respectively. Using the Cox regression model, tumor size, Ki67, CK20, and N stage were identified as independent predictors of overall recurrence. A nomogram predicting the 1-, 2-, and 3-year cumulative rate of overall recurrence was then developed and internally validated, with a bias-corrected C-index of 0.723 (95% CI, 0.675 to 0.771) and a small extent of "over-fitting" (0.8%). Risk factors of site-specific recurrence were also discovered. Additionally, using competing risk analyses, N stage, lymphovascular invasion (LVI) and CK5/6 were found as independent predictors of loco-regional recurrence. Among patients with N2-positive disease (n=91), adjuvant radiotherapy tended to prolong disease free survival (DFS) (P=0.067), but not overall survival (OS) (P=0.271).

Conclusions

This study provides the proof of concept of using routine IHC markers, along with common clinical-pathological parameters, in predicting postoperative recurrence among completely resected EGFR-mutant NSCLC. Adjuvant radiotherapy may improve DFS, but hard to prolong OS in N2-positive EGFR-mutant NSCLC without further biomarker-guided patients' selection.

Long non-coding RNA BRE-AS1 represses non-small cell lung cancer cell growth and survival via up-regulating NR4A3

Recently, several long non-coding RNAs (lncRNAs) have been revealed to play crucial roles in tumorigenesis and progression of many cancers. Nevertheless, more than 50,000 lncRNAs were identified in human cells and the roles of majority of these lncRNAs in non-small cell lung cancer (NSCLC) are unknown. In this study, using public NSCLC microarray data we identified a novel lncRNA BRE antisense RNA 1 (BRE-AS1). BRE-AS1 is significantly down-regulated in NSCLC tissues and cell lines. Gain-of-function and loss-of-function assays showed that BRE-AS1 reduces NSCLC cell viability, represses NSCLC cell proliferation, and induces NSCLC cell apoptosis in vitro, and represses NSCLC tumor growth in vivo. Mechanistic investigation revealed that BRE-AS1 physically binds STAT3, reduces the binding of STAT3 to the promoter of NR4A3, relieves the repression of NR4A3 caused by STAT3, and up-regulates NR4A3 expression. Consistently, NR4A3 is significantly down-regulated in NSCLC tissues and the expression of NR4A3 is positively correlated with the expression of BRE-AS1 in NSCLC tissues. In addition, depletion of NR4A3 attenuates the tumor suppressive roles of BRE-AS1 in NSCLC. Collectively, our data demonstrate that BRE-AS1 represses NSCLC cell growth and survival via up-regulating NR4A3 and suggest that enhancing BRE-AS1 may be potential therapeutic strategy for NSCLC.

Survival analysis in Caucasian pulmonary adenocarcinoma patients based on differential targets between Caucasian and Asian population

Ethnicity differences may contribute to the variety of overall survival in pulmonary adenocarcinoma, while the influence of ethnicity relevant somatic driver mutations (ERSDM) profile on Caucasian survival is not well investigated. In this study, we studied epidermal growth factor receptor (EGFR), tumor protein p53 (TP53), Kirsten rat sarcoma 2 viral oncogene homolog (KRAS), and Serine/Threonine Kinase 11 (STK11) to construct the ERSDM profile. Those genes were selected as harboring somatic driver mutations with >10% prevalence and with different occurrence between Caucasian and Asian ethnicity. Clinical information and transcriptome sequencing of 173 Caucasian pulmonary adenocarcinoma patients with matched mutation data are retrieved from TCGA, Kaplan-Meier analyses and Cox proportional-hazards regression models are further used to analyze the effect of the ERSDM profile on overall survival. There is no significant correlation between single gene mutation and overall survival, while patients with less than two mutated genes have a better overall survival compared with those with at least two mutated genes (p = 0.034). All of these indicate that multiple mutations in the ERSDM profile may be a negative prognostic factor for overall survival in Caucasian pulmonary adenocarcinoma patients.

Recurrence risk after preoperative biopsy in patients with resected early-stage non-small-cell lung cancer: a retrospective study

Background

Tumor cell dissemination after needle biopsy has been reported in a variety of malignancies, including non-small-cell lung cancer (NSCLC). However, there is little clinical evidence in regard to whether preoperative biopsy increases the risk of recurrence in completely resected NSCLC.

Patients and methods

A total of 322 patients diagnosed as pathological stage I NSCLC using intraoperative biopsy (IOB) (control group), preoperative percutaneous needle biopsy (PNB) or bronchoscopic biopsy were included in this study. Baseline characteristics were collected and compared. The disease-free survival (DFS) of patients was analyzed using Kaplan–Meier method. Subgroup analysis and Cox regression were performed to evaluate the effect of preoperative biopsy on recurrence risk with adjustment for potential confounders.

Results

Among these patients, 202 (63%) underwent IOB, 66 (20%) underwent PNB, and 54 (17%) underwent bronchoscopic biopsy. DFS of patients who had preoperative PNB or bronchoscopic biopsy was similar to those who had IOB (P=0.514 and 0.869). Neither preoperative PNB nor transbronchial biopsy significantly affected recurrence incidence across all the relevant subgroups. Furthermore, multivariate analysis showed that preoperative biopsy was not associated with increased recurrence risk in NSCLC patients with adjustment for confounders, while squamous cell carcinoma and adjuvant chemotherapy were associated with prolonged DFS.

Conclusion

Neither preoperative PNB nor bronchoscopic biopsy increased the recurrence risk in patients with resected stage I NSCLC, indicating that these procedures could be safely used for diagnosis of early-stage NSCLC.