Comprehensive Clinical Staging for Resectable Lung Cancer: Clinicopathological Correlations and the Role of Brain MRI

Does clinical T1N0 GGN really require checking for distant metastasis during initial staging for lung cancer?

BACKGROUND

Accurate clinical staging is crucial for selection of optimal oncological treatment strategies in non-small cell lung cancer (NSCLC). Although brain MRI, bone scintigraphy and whole-body PET/CT play important roles in detecting distant metastases, there is a lack of evidence regarding the indication for metastatic staging in early NSCLCs, especially ground-grass nodules (GGNs). Our aim was to determine whether checking for distant metastasis is required in cases of clinical T1N0 GGN.

METHODS

This was a retrospective study of initial staging using imaging tests in patients who had undergone complete surgical R0 resection for clinical T1N0 Stage IA NSCLC.

RESULTS

A total of 273 patients with cT1N0 GGNs (n = 183) or cT1N0 solid tumors (STs, n = 90) were deemed eligible. No cases of distant metastasis were detected on initial routine imaging evaluations. Among all cT1N0M0 cases, there were 191 incidental findings on various modalities (128 in the GGN). Most frequently detected on brain MRI was cerebral leukoaraiosis, which was found in 98/273 (35.9%) patients, while cerebral infarction was detected in 12/273 (4.4%) patients. Treatable neoplasms, including brain meningioma and thyroid, gastric, renal and colon cancers were also detected on PET/CT (and/or MRI). Among those, 19 patients were diagnosed with a treatable disease, including other-site cancers curable with surgery.

CONCLUSIONS

Extensive staging (MRI, scintigraphy, PET/CT etc.) for distant metastasis is not required for patients diagnosed with clinical T1N0 GGNs, though various imaging modalities revealed the presence of adventitious diseases with the potential to increase surgical risks, lead to separate management, and worsen patient outcomes, especially in elderly patients. If clinically feasible, it could be considered to complement staging with whole-body procedures including PET/CT.

Systematic Literature Review to Identify Cost and Resource Use Data in Patients with Early-Stage Non-small Cell Lung Cancer (NSCLC)

BACKGROUND

Approximately 2 million new cases and 1.76 million deaths occur annually due to lung cancer, with the main histological subtype being non-small cell lung cancer (NSCLC). The costs and resource use associated with NSCLC are important considerations to understand the economic impact imposed by the disease on patients, caregivers and healthcare services.

OBJECTIVE

The objective of this systematic literature review (SLR) is to provide a comprehensive overview of the available direct medical costs, direct non-medical costs, indirect costs, cost drivers and resource use data available for patients with early-stage NSCLC.

METHODS

Electronic searches were conducted via the Ovid platform in March 2021 and June 2022 and were supplemented by grey literature searches. Eligible patients had early-stage (stage I-III) resectable NSCLC and received treatment in the neoadjuvant or adjuvant setting. There was no restriction on intervention or comparators. Publication date was restricted to 2011 onwards, and English language publications or non-English language publications with an English abstract were of primary interest. Due to the anticipation of many studies meeting the inclusion criteria, analyses were restricted to full publications from countries of primary interest (Australia, Brazil, Canada, China, France, Germany, Italy, Japan, South Korea, Spain, UK and the US) and those with > 200 patients. The Molinier checklist was applied to conduct quality assessment.

RESULTS

Forty-two full publications met the eligibility criteria and were included in this SLR. Early-stage NSCLC was associated with significant direct medical costs and healthcare utilisation, and the economic burden of the disease increased with its progression. Surgery was the primary cost driver in stage I patients, but as patients progressed to stage II and III, treatments such as chemotherapy and radiotherapy, and inpatient care became the main cost drivers. There was no significant difference in resource use between patients with early-stage disease. However, these data were heavily US-centric and there was a paucity of data relating to direct non-medical and indirect costs associated with early-stage NSCLC.

CONCLUSIONS

Preventing disease progression for patients with NSCLC could reduce the economic burden of NSCLC on patients, caregivers and healthcare systems. This review provides a comprehensive overview of the available cost and resource use data in this indication, which is important in guiding the decisions of policy makers regarding the allocation of resources. However, it also indicates a need for more studies comparing the economic impact of NSCLC in markets in addition to the US.

Specific organ metastases and prognosis in lung adenocarcinoma

OBJECTIVES

This study aims to characterize the specific organ metastatic rates in lung adenocarcinoma (LUAD) patients and identify the prognosis-associated factors.

METHODS

Using the Surveillance, Epidemiology and End Results database, 40 117 patients diagnosed with positive histology as the only primary LUAD were included. We stratified patients by diagnosed year, age, sex, race/ethnicity, marital status, insurance, location, TNM stage, organ-specific metastases, surgery, chemotherapy, and radiation therapy. We performed multivariable logistic and Cox regression to identify the factors associated with the presence of specific organ metastases and prognosis predictors.

RESULTS

For the 40 117 LUAD patients, 43.69%, 26.25%, 19.66%, 10.60%, and 17.89% had specific organ, bone, brain, liver, and lung metastases, respectively. The average survival in patients with organ metastases was 12.19 months, compared to 36.40 months in patients without metastases. In different kinds of metastatic organ cohorts, the longest average survival was 12.60 months in the lung metastases cohort, and the shortest was 8.43 months in liver metastases cohort. In total, 571 patients with metastases received surgery, which was significantly associated with decreased mortality (hazard ratio 1.82, 95% confidence interval 1.65-2.01, p < 0.01). Patients received surgery of lobectomy or extended (251 of 571, 43.96%) displayed the longest average survival (35.16 months); patients (294 of 571, 51.49%) received sub-lobar resection, had the average survival (19.90 months); patients received local tumor destruction (26 of 571, 4.55%) had the shortest average survival (13.73 months).

CONCLUSION

This study provides insights into the specific organ metastatic rates and prognosis in LUAD patients on a population level. These findings suggest that surgery resection should be taken into consideration in the treatment for these LUAD patients.

The role of brain radiotherapy for EGFR- and ALK-positive non-small-cell lung cancer with brain metastases: a review

Non-small cell lung cancer (NSCLC) is frequently complicated by central nervous system (CNS) metastases affecting patients' life expectancy and quality. At the present clinical trials including neurosurgery, radiotherapy (RT) and systemic treatments alone or in combination have provided controversial results. CNS involvement is even more frequent in NSCLC patients with EGFR activating mutations or ALK rearrangement suggesting a role of target therapy in the upfront treatment in place of loco-regionals treatments (i.e. RT and/or surgery). So far clinical research has not explored the potential role of accurate brain imaging (i.e. MRI instead of the routine total-body contrast CT and/or PET/CT staging) to identify patients that could benefit of local therapies. Moreover, for patients who require concomitant RT there are no clear guidelines on the timing of intervention with respect to innovative precision medicine approaches with Tyrosine Kinase Inhibitors, ALK-inhibitors and/or immuno-oncological therapies. On this basis the present review describes the therapeutic strategies integrating medical and radiation oncology in patients with metastatic NSCLC (mNSCLC) adenocarcinoma with CNS involvement and EGFR activating mutations or ALK rearrangement.

Machine Learning for the Prediction of Synchronous Organ-Specific Metastasis in Patients With Lung Cancer

Background

This study aimed to develop an artificial neural network (ANN) model for predicting synchronous organ-specific metastasis in lung cancer (LC) patients.

Methods

A total of 62,151 patients who diagnosed as LC without data missing between 2010 and 2015 were identified from Surveillance, Epidemiology, and End Results (SEER) program. The ANN model was trained and tested on an 75/25 split of the dataset. The receiver operating characteristic (ROC) curves, area under the curve (AUC) and sensitivity were used to evaluate and compare the ANN model with the random forest model.

Results

For distant metastasis in the whole cohort, the ANN model had metrics AUC = 0.759, accuracy = 0.669, sensitivity = 0.906, and specificity = 0.613, which was better than the random forest model. For organ-specific metastasis in the cohort with distant metastasis, the sensitivity in bone metastasis, brain metastasis and liver metastasis were 0.913, 0.906 and 0.925, respectively. The most important variable was separate tumor nodules with 100% importance. The second important variable was visceral pleural invasion for distant metastasis, while histology for organ-specific metastasis.

Conclusions

Our study developed a “two-step” ANN model for predicting synchronous organ-specific metastasis in LC patients. This ANN model may provide clinicians with more personalized clinical decisions, contribute to rationalize metastasis screening, and reduce the burden on patients and the health care system.

Endobronchial Ultrasound Staging of Operable Non-small Cell Lung Cancer: Do Triple-Normal Lymph Nodes Require Routine Biopsy?

BACKGROUND

Staging guidelines for lung cancer recommend endobronchial ultrasound (EBUS) and systematic biopsy of at least three mediastinal lymph node (LN) stations for accurate staging. A four-point ultrasonographic score (Canada Lymph Node Score [CLNS]) was developed to determine the probability of malignancy in each LN. A LN with a CLNS of < 2 is considered low probability for malignancy. We hypothesized that, in patients with cN0 non-small cell lung cancer, LNs with CLNS of < 2 may not require routine biopsy because they represent true node-negative disease.

RESEARCH QUESTION

Do LNs considered triple normal on CT scanning, PET scanning, and CLNS evaluation require routine biopsy?

STUDY DESIGN AND METHODS

LNs were evaluated for ultrasonographic features at the time of EBUS and the CLNS was applied. Triple-normal LNs were defined as cN0 on CT scanning (short axis, < 1 cm), PET scanning (no hypermetabolic activity), and EBUS (CLNS, < 2). Specificity and negative predictive value (NPV) were calculated against the gold standard pathologic diagnosis from surgically excised specimens.

RESULTS

In total, 143 LNs from 57 cN0 patients were assessed. Triple-normal LNs showed a specificity and NPV of 60% (95% CI, 51.2%-68.3%) and 93.1% (95% CI, 85.6%-97.4%), respectively. After pathologic assessment, only 5.6% (n = 8/143) of triple-normal nodes were proven to be malignant.

INTERPRETATION

At the time of staging for lung cancer, combining CT scanning, PET scanning, and CLNS criteria can identify triple-normal LNs that have a high NPV for malignancy. This raises the question of whether triple-normal LNs require routine sampling during EBUS and transbronchial needle aspiration. A prospective trial is required to confirm these findings.

Diagnostic Yield of Staging Brain MRI in Patients with Newly Diagnosed Non-Small Cell Lung Cancer

Background Existing guidelines are inconsistent regarding the indications for staging brain MRI in patients with newly diagnosed, early-stage non-small cell lung cancer (NSCLC). Purpose To evaluate the diagnostic yield of staging brain MRI in the initial evaluation of lung cancer. Materials and Methods This retrospective, observational, single-institution study included patients with newly diagnosed NSCLC who underwent staging chest CT and staging brain MRI from November 2017 to October 2018. Diagnostic yield was defined as the proportion of patients with brain metastases among all patients. Yield was stratified into clinical stage groups per the eighth edition of the American Joint Committee on Cancer staging guidelines, based on staging chest CT and in adenocarcinoma with epidermal growth factor receptor (EGFR) gene mutation and anaplastic lymphoma kinase (ALK) gene rearrangement. Subgroup analyses were performed on the basis of cell types and molecular markers. The χ² test was performed to compare the diagnostic yields, and Bonferroni correction was used to account for multiple testing between stage groups. Results A total of 1712 patients (mean age, 64 years ± 10 [standard deviation]; 1035 men) were included. The diagnostic yield of staging brain MRI in newly diagnosed NSCLC was 11.9% (203 of 1712; 95% confidence interval [CI]: 10.4%, 13.5%). In clinical stage IA, IB, and II disease, the diagnostic yields were 0.3% (two of 615; 95% CI: 0.0%, 1.2%), 3.8% (seven of 186; 95% CI: 1.5%, 7.6%), and 4.7% (eight of 171; 95% CI: 2.0%, 9.0%), respectively. The diagnostic yield was higher in patients with adenocarcinoma (13.6%; 176 of 1297; 95% CI: 11.8%, 15.6%) than squamous cell carcinoma (5.9%; 21 of 354; 95% CI: 3.7%, 8.9%) and in patients with EGFR mutation-positive adenocarcinoma (17.5%; 85 of 487; 95% CI: 14.2%, 21.1%) than with EGFR mutation-negative adenocarcinoma (10.6%; 68 of 639; 95% CI: 8.4%, 13.3%) (P < .001 for both). Conclusion The diagnostic yield of staging brain MRI in clinical stage IA non-small cell lung cancer was low, but staging brain MRI had a higher diagnostic yield in clinical stage IB and epidermal growth factor receptor mutation-positive adenocarcinoma. © RSNA, 2020 Online supplemental material is available for this article.

Impact of neuroimaging in the pretreatment evaluation of early stage non-small cell lung cancer

Background

There are limited data and conflicting guideline recommendations regarding the role of neuroimaging in the pretreatment evaluation of non-small cell lung cancer (NSCLC).

Methods

We performed a retrospective, pragmatic cohort study of patients with NSCLC diagnosed between January 1 and December 31, 2015. Eligible patients were identified from an institutional tumor registry. We collected all records of pretreatment neuroimaging within 12 weeks of diagnosis, including CT head (CT) and MRI brain (MRI). We abstracted the indication for neuroimaging, presence of central neurologic symptoms and cancer stage (with and without neuroimaging findings) from the tumor registry and the electronic health record.

Results

We identified 216 evaluable patients with newly diagnosed NSCLC. 157 of 216 patients (72.7%) underwent neuroimaging as part of initial staging, and 41 (26%) were found to have brain metastases. Of 43 patients with central neurologic symptoms at the time of neuroimaging, 28 (67%) had brain metastasis. In patients without central neurologic symptoms, brain metastases were discovered in 0 of 33 patients with clinical stage I or II, 4 of 36 (11%) with clinical stage III and 9 of 45 (20%) with clinical stage IV disease.

Conclusions

In patients with early stage NSCLC (i.e. clinical stage I and II) without central neurologic symptoms, brain metastases are unlikely. The continued use of neuroimaging in the pretreatment evaluation of clinical stage I patients without central neurologic symptoms is not needed.

Micropapillary pattern is associated with the development of brain metastases and the reduction of survival time in EGFR-mutation lung adenocarcinoma patients with surgery

OBJECTIVE

The role of micropapillary pattern (MIP) in EGFR-mutated NSCLC patients with brain metastases (BM) after complete surgical resection still remains unclear. Therefore, a retrospective study was conducted to evaluate the role of MIP in those patients.

METHODS

This study included 332 stage I-III patients with EGFR-mutant lung adenocarcinoma and complete resection. Patients were classified in four groups: the MIP-positive patients without BM development, the MIP-negative patients without BM development, the MIP-positive patients with BM development and the MIP-negative patients with BM development. Intracranial disease-free survival (iDFS), systemic disease-free survival (DFS) and overall survival (OS) were evaluated.

RESULTS

The median OS in the whole group was 70 months. The patients with MIP show inferior DFS (13 months vs. 22 months; P < 0.001) and OS (56 months vs. 74 months; P < 0.001). Furthermore, BM development was more likely to be found in patients with MIP (P = 0.001). In addition, the MIP-positive patients showed a significantly shorter iDFS compared with MIP-negative patients (14.5 months vs. 26 months; P < 0.001). Furthermore, the MIP-positive patients had significantly inferior iDFS in both BM as first line development groups (13 months vs. 19 months; P < 0.001) and BM as non-first line development groups (18 months vs. 33 months; P = 0.007).

CONCLUSIONS

MIP was related to the earlier recurrence and shortened survival time. In addition, MIP was an independent poor prognostic factor for the increase of BM rate and the shortened time of BM development after surgery.