Neoadjuvant therapy in non-small cell lung cancer: basis, promise, and challenges.

Introduction: Survival rates for early-stage non-small cell lung cancer (NSCLC) remain poor despite the decade-long established standard of surgical resection and systemic adjuvant therapy. Realizing this, researchers are exploring novel therapeutic targets and deploying neoadjuvant therapies to predict and improve clinical and pathological outcomes in lung cancer patients. Neoadjuvant therapy is also increasingly being used to downstage disease to allow for resection with a curative intent. In this review, we aim to summarize the current and developing landscape of using neoadjuvant therapy in the management of NSCLC. Methods: The PubMed.gov and the ClinicalTrials.gov databases were searched on 15 January 2023, to identify published research studies and trials relevant to this review. One hundred and seven published articles and seventeen ongoing clinical trials were selected, and relevant findings and information was reviewed. Results & Discussion: Neoadjuvant therapy, proven through clinical trials and meta-analyses, exhibits safety and efficacy comparable to or sometimes surpassing adjuvant therapy. By attacking micro-metastases early and reducing tumor burden, it allows for effective downstaging of disease, allowing for curative surgical resection attempts. Research into neoadjuvant therapy has necessitated the development of surrogate endpoints such as major pathologic response (MPR) and pathologic complete response (pCR) allowing for shorter duration clinical trials. Novel chemotherapy, immunotherapy, and targeted therapy agents are being tested at a furious rate, paving the way for a future of personalized systemic therapy in NSCLC. However, challenges remain that prevent further mainstream adoption of preoperative (Neoadjuvant) therapy. These include the risk of delaying curative surgical resection in scenarios of adverse events or treatment resistance. Also, the predictive value of surrogate markers of disease cure still needs robust verification. Finally, the body of published data is still limited compared to adjuvant therapy. Addressing these concerns with more large scale randomized controlled trials is needed.

Skeletal muscle index is associated with long term outcomes after lobectomy for non-small cell lung cancer.

BACKGROUND: Skeletal muscle indices have been associated with improved peri-operative outcomes after surgical resection of non-small-cell lung cancer (NSCLC). However, it is unclear if these indices can predict long term cancer specific outcomes. METHODS: NSCLC patients undergoing lobectomy at our institute between 2009-2015 were included in this analysis (N = 492). Preoperative CT scans were used to quantify skeletal muscle index (SMI) at L4 using sliceOmatic software. Cox proportional modelling was performed for overall (OS) and recurrence free survival (RFS). RESULTS: For all patients, median SMI was 45.7 cm2/m2 (IQR, 40-53.8). SMI was negatively associated with age (R = -0.2; p < 0.05) and positively associated with BMI (R = 0.46; P < 0.05). No association with either OS or RFS was seen with univariate cox modelling. However, multivariable modelling for SMI with patient age, gender, race, smoking status, DLCO and FEV1 (% predicted), American Society of Anesthesiology (ASA) score, tumor histology and stage, and postoperative neoadjuvant therapy showed improved OS (HR = 0.97; P = 0.0005) and RFS (HR = 0.97; P = 0.01) with SMI. Using sex specific median SMI as cutoff, a lower SMI was associated with poor OS (HR = 1.65, P = 0.001) and RFS (HR = 1.47, P = 0.03). CONCLUSIONS: SMI is associated with improved outcomes after resection of NSCLC. Further studies are needed to understand the biological basis of this observation. This study provides additional rationale for designing and implementation of rehabilitation trials after surgical resection, to gain durable oncologic benefit.

Obesity and lung cancer-a narrative review.

Background and Objective: A highly nuanced relationship exists between obesity and lung cancer. The association between obesity and lung cancer risk/prognosis varies depending on age, gender, race, and the metric used to quantify adiposity. Increased body mass index (BMI) is counterintuitively associated with decreased lung cancer incidence and mortality, giving rise to the term 'obesity paradox'. Potential explanations for this paradox are BMI being a poor measure of obesity, confounding by smoking and reverse causation. A literature search of this topic yields conflicting conclusions from various authors. We aim to clarify the relationship between various measures of obesity, lung cancer risk, and lung cancer prognosis. Methods: The PubMed database was searched on 10 August 2022 to identify published research studies. Literature published in English between 2018 and 2022 were included. Sixty-nine publications were considered relevant, and their full text studied to collate information for this review. Key Content and Findings: Lower lung cancer incidence and better prognosis was associated with increased BMI even after accounting for smoking and pre-clinical weight loss. Individuals with high BMI also responded better to treatment modalities such as immunotherapy compared to individuals with a normal BMI. However, these associations varied highly depending on age, gender, and race. Inability of BMI to measure body habitus is the main driver behind this variability. The use of anthropometric indicators and image-based techniques to quantify central obesity easily and accurately is on the rise. Increase in central adiposity is associated with increased incidence and poorer prognosis of lung cancer, contrasting BMI. Conclusions: The obesity paradox may arise due to the improper use of BMI as a measure of body composition. Measures of central obesity better portray the deleterious effects of obesity and are more appropriate to be discussed when talking about lung cancer. The use of obesity metrics based on anthropometric measurements and imaging modalities has been shown to be feasible and practical. However, a lack of standardization makes it difficult to interpret the results of studies using these metrics. Further research must be done to understand the association between these obesity metrics and lung cancer.

Survival Benefit of Perioperative Systemic Chemotherapy for Patients With N0 to N1 NSCLC Having Synchronous Brain Metastasis.

Introduction: In stage IV NSCLC with solitary or oligometastatic brain metastasis, surgical resection of the primary and definitive management of the brain metastasis is an accepted standard. However, the effect of systemic chemotherapy after surgical resection on overall survival is not well-established. Methods: We used the National Cancer Database to retrospectively identify individuals with NSCLC as the primary tumor along with synchronous brain metastases who underwent thoracic resection with or without adjuvant chemotherapy. Chi-square and Wilcoxon rank sum tests were performed to compare categorical and continuous variables, respectively, across the treatment groups. Kaplan-Meier and Cox proportional modeling were done to determine the survival benefit. Results: A total of 310 (71.9%) of the cohort received perioperative chemotherapy, most of whom (79.4%) received it in the adjuvant setting. Patients receiving chemotherapy were likely to be younger (p = 0.002), privately insured (p = 0.01), and receive radiation (p < 0.001). Perioperative chemotherapy was significantly associated with survival on both univariate (hazard ratio = 0.71[0.52 - 0.99]) and multivariable (hazard ratio = 0.66 [0.47 - 0.92]) in addition to age (p = 0.03), Charlson-Deyo score (p = 0.02), pathologic N stage (p = 0.02), and adenocarcinoma histology (p = 0.02). Kaplan-Meier analysis confirmed this result with a significantly better survival with perioperative chemotherapy (p = 0.02). Further subgroup analysis using pathologic N stage revealed similar effect in pN1 (p = 0.001), but not pN0 (p = 0.2) patients. Conclusions: Perioperative chemotherapy for pN0-1 NSCLC with synchronous brain metastasis is associated with improved OS in this analysis.

Immunoprofiling bronchoalveolar lavage cells reveals multifaceted smoking-associated immune dysfunction.

Background: Bronchoalveolar lavage (BAL) is an underutilised tool in the search for pulmonary disease biomarkers. While leukocytes with effector and suppressor function play important roles in airway immunity and tumours, it remains unclear if frequencies and phenotypes of BAL leukocytes can be useful parameters in lung cancer studies and clinical trials. We therefore explored the utility of BAL leukocytes as a source of biomarkers interrogating the impact of smoking, a major lung cancer risk determinant, on pulmonary immunity. Methods: In this "test case" observational study, BAL samples from 119 donors undergoing lung cancer screening and biopsy procedures were evaluated by conventional and spectral flow cytometry to exemplify the comprehensive immune analyses possible with this biospecimen. Proportions of major leukocyte populations and phenotypic markers levels were found. Multivariate linear rank sum analysis considering age, sex, cancer diagnosis and smoking status was performed. Results: Significantly increased frequencies of myeloid-derived suppressor cells and PD-L1-expressing macrophages were found in current and former smokers compared to never-smokers. While cytotoxic CD8 T-cells and conventional CD4 helper T-cell frequencies were significantly reduced in current and former smokers, expression of immune checkpoints PD-1 and LAG-3 as well as Tregs proportions were increased. Lastly, the cellularity, viability and stability of several immune readouts under cryostorage suggested BAL samples are useful for correlative end-points in clinical trials. Conclusions: Smoking is associated with heightened markers of immune dysfunction, readily assayable in BAL, that may reflect a permissive environment for cancer development and progression in the airway.

Association between visceral obesity, metformin use, and recurrence risk in early-stage colorectal cancer.

We sought to investigate the association between visceral obesity with disease recurrence and survival in early-stage colorectal cancer (CRC) patients. We also wanted to examine if such an association, if exists, is influenced by metformin use. Stage I/II CRC adenocarcinoma patients treated surgically were identified. L3 level CT VFI (visceral fat index) was used as a metric of visceral obesity and was calculated as the proportion of total fat area composed of visceral fat. N = 492. 53% were males, 90% were Caucasians, 35% had stage I disease, and 14% used metformin. 20.3% patients developed a recurrence over a median follow-up of 56 months. VFI was associated with both RFS and OS in a multivariate model, but not BMI. The final multivariate model for RFS included an interaction term for VFI and metformin (p = 0.04). Confirming this result, subgroup analysis showed an increasing VFI was associated with a poor RFS (p = 0.002), and OS (p < 0.001) in metformin non-users only and metformin use was associated with a better RFS only in the top VFI tertile (p = 0.01). Visceral obesity, but not BMI, is associated with recurrence risk and poorer survival in stage I/II CRC. Interestingly, this association is influenced by metformin use.

Geographical Disparities in Esophageal Cancer Incidence and Mortality in the United States.

BACKGROUND: Our previous research on neuroendocrine and gastric cancers has shown that patients living in rural areas have worse outcomes than urban patients. This study aimed to investigate the geographic and sociodemographic disparities in esophageal cancer patients. METHODS: We conducted a retrospective study on esophageal cancer patients between 1975 and 2016 using the Surveillance, Epidemiology, and End Results database. Both univariate and multivariable analyses were performed to evaluate overall survival (OS) and disease-specific survival (DSS) between patients residing in rural (RA) and urban (MA) areas. Further, we used the National Cancer Database to understand differences in various quality of care metrics based on residence. RESULTS: N = 49,421 (RA [12%]; MA [88%]). The incidence and mortality rates were consistently higher during the study period in RA. Patients living in RA were more commonly males (p < 0.001), Caucasian (p < 0.001), and had adenocarcinoma (p < 0.001). Multivariable analysis showed that RA had worse OS (HR = 1.08; p < 0.01) and DSS (HR = 1.07; p < 0.01). Quality of care was similar, except RA patients were more likely to be treated at a community hospital (p < 0.001). CONCLUSIONS: Our study identified geographic disparities in esophageal cancer incidence and outcomes despite the similar quality of care. Future research is needed to understand and attenuate such disparities.

Visceral Obesity in Non-Small Cell Lung Cancer.

While obesity measured by body mass index (BMI) has been paradoxically associated with reduced risk and better outcome for lung cancer, recent studies suggest that the harm of obesity becomes apparent when measured as visceral adiposity. However, the prevalence of visceral obesity and its associations with demographic and tumor features are not established. We therefore conducted an observational study of visceral obesity in 994 non-small cell lung cancer (NSCLC) patients treated during 2008-2020 at our institution. Routine computerized tomography (CT) images of the patients, obtained within a year of tumor resection or biopsy, were used to measure cross-sectional abdominal fat areas. Important aspects of the measurement approach such as inter-observer variability and time stability were examined. Visceral obesity was semi-quantified as visceral fat index (VFI), the fraction of fat area that was visceral. VFI was found to be higher in males compared to females, and in former compared to current or never smokers. There was no association of VFI with tumor histology or stage. A gene expression-based measure of tumor immunogenicity was negatively associated with VFI but had no bearing with BMI. Visceral obesity is appraisable in routine CT and can be an important correlate in lung cancer studies.