Brain Imaging for Staging of Patients With Clinical Stage IA Non-small Cell Lung Cancer in the National Lung Screening Trial: Adherence With Recommendations From the Choosing Wisely Campaign

Asian Thoracic Oncology Research Group expert consensus statement on the peri-operative management of non-small cell lung cancer

The peri-operative management of non-small cell lung cancer (NSCLC) in earlier stage disease has seen significant advances in recent years with the incorporation of immune checkpoint inhibitors and targeted therapy. However, many unanswered questions and challenges remain, including the application of clinical trial data to routine clinical practice. Recognising the unique demographic profile of Asian patients with NSCLC and heterogeneous healthcare systems, the Asian Thoracic Oncology Research Group (ATORG) convened a consensus meeting in Singapore on 26 April 2024 to discuss relevant issues spanning diagnostic testing to post-neoadjuvant treatment considerations and future directions. An interdisciplinary group of 19 experts comprising medical oncologists, thoracic surgeons, radiation oncologists, pulmonologists and pathologists from Singapore, Hong Kong, Mainland China, Korea, Japan, Taiwan, India, Malaysia, Thailand, Vietnam and Australia met to discuss emerging data, identify existing gaps in clinical care and develop a multidisciplinary, multinational expert consensus statement on the peri-operative management of NSCLC tailored to the Asia-Pacific region.

Brain Imaging in Patients with Non-Small Cell Lung Cancer-A Systematic Review

Background: Lung cancer frequently metastasizes to the brain, liver, and adrenal glands with a significant negative prognostic impact on overall survival and quality of life (QoL). To optimize treatment and prognosis, adequate staging with the detection of distant metastases is crucial. The incidence of brain metastases in potentially resectable early-stage non-small cell lung cancer (NSCLC) is as low as 3%; hence, the need for preoperative brain imaging has been a constant matter of debate, especially in stage II. In stages III and IV NSCLC, neuroimaging is an essential part of staging. Methods: A systematic literature search was performed. Publications from 1999 to 2024, focusing on preoperative brain imaging (BI) in the staging of stages I-IV NSCLC, were included. Data extraction included study population characteristics, the modality of BI, the incidence of brain metastases (BMs), and the main outcomes of the studies. The final included studies were selected according to the PRISMA criteria. In the second step, guidelines on BI in NSCLC staging of major importance were identified and compared. Results: A total of 530 articles were identified, of which 25 articles were selected. Four prospective studies and 21 retrospective investigations were included. Most of the investigations focused on BI in the early stages. The main imaging modality for BI was magnetic resonance imaging (MRI), followed by computed tomography (CT). Besides the identified 25 studies, the most important internationally applied guidelines on brain imaging in the staging of NSCLC were reviewed. While some guidelines agree on preoperative BI in NSCLC stage III (Union for International Cancer Control-UICC eighth edition) patients, other guidelines recommend earlier BI starting from clinical stage II. All mentioned guidelines homogenously recommend BI in patients with symptoms suggestive of brain pathologies. Conclusions: BI in NSCLC staging is recommended in neurologically symptomatic patients suggestive of brain metastases as well as NSCLC patients with stage III disease. Neuroimaging in stage IA patients, as well as in pure GGO (Ground-Glass Opacity) lesions, was considered unnecessary. The predominantly applied imaging modality was ce-MRI (contrast-enhanced magnetic resonance imaging). Inconsistency exists concerning BI in stage II. The identification of prognostic factors for developing BM in patients with early-stage NSCLC could help to clarify which subgroup might benefit from preoperative BI.

Role of Pre-Operative Brain Imaging in Patients with NSCLC Stage I: A Retrospective, Multicenter Analysis

Simple Summary

Lung cancer is the worldwide leading cause of cancer-related death among both genders, with about 230,000 patients/year being diagnosed in the US alone. It accounts for about 40% of all brain metastases, which already occur in around 3% of early-stage patients. Nonetheless, current international guidelines do not unanimously recommend brain imaging for use in the early stages of cancer. Some studies have suggested that surgical or radiosurgical treatment of brain metastases may provide better survival, especially in asymptomatic patients. Additionally, advances in genome analysis have identified molecular targets for pharmaceutical agents. These recent advancements in treatment stress the importance of studying incidence as well as patient and tumor characteristics in order to potentially adapt future guidelines and provide the best possible treatment for early-stage lung cancer. This multicentric study analyzed the data of 577 patients diagnosed with early-stage lung cancer who had been submitted for brain imaging at initial tumor staging.

Abstract

Background: Lung cancer is the worldwide leading oncological cause of death in both genders combined and accounts for around 40–50% of brain metastases in general. In early-stage lung cancer, the incidence of brain metastases is around 3%. Since the early detection of asymptomatic cerebral metastases is of prognostic value, the aim of this study was to analyze the incidence of brain metastases in early-stage lung cancer and identify possible risk factors. Methods: We conducted a retrospective multicentric analysis of patients with Stage I (based on T and N stage only) Non-Small Cell Lung Cancer (NSCLC) who had received preoperative cerebral imaging in the form of contrast-enhanced CT or MRI. Patients with a history of NSCLC, synchronous malignancy, or neurological symptoms were excluded from the study. Analyzed variables were gender, age, tumor histology, cerebral imaging findings, smoking history, and tumor size. Results were expressed as mean with standard deviation or median with range. Results: In total, 577 patients were included in our study. Eight (1.4%) patients were found to have brain metastases in preoperative brain imaging. Tumor histology was adenocarcinoma in all eight cases. Patients were treated with radiotherapy (five), surgical resection (two), or both (one) prior to thoracic surgical treatment. Other than tumor histology, no statistically significant characteristics were found to be predictive of brain metastases. Conclusion: Given the low incidence of brain metastases in patients with clinical Stage I NSCLC, brain imaging in this cohort could be avoided.

Revisiting Indications for Brain Imaging During the Clinical Staging Evaluation of Lung Cancer

Introduction

Available guidelines are inconsistent as to whether patients with newly diagnosed clinical stage II NSCLC should receive routine brain imaging.

Methods

The National Cancer Database was queried for the prevalence of isolated brain metastases among patients with newly diagnosed NSCLC in 2016 and 2017. Patients with metastases in locations other than the brain were excluded. The prevalences were then stratified by clinical T and N classifications and further stratified into a summary stage, which was calculated based on T and N classifications. The summary stage represents the clinical stage that would have been available at the time of decision for brain imaging.

Results

A total of 6,949 of 149,958 patients (4.6%) with clinical stages I, II, III, or brain-limited stage IV NSCLC had dissemination limited to the brain. As T and N stages increased, prevalence of brain metastases generally increased. Among patients with node-negative (N0) NSCLC, the prevalence of brain-only metastases increased from 1.2% in patients with T1a to 3.8% among patients with T4 (p < 0.001). Among patients with T1a, the prevalence of brain-only metastases increased from 1.2% for patients with N0 to 7.9% for patients with N3 (p < 0.001). The prevalence of brain-limited metastases generally increased with increasing summary stage. The prevalence of brain-only metastases among patients with stage IA was 1.7% whereas that among patients with stage IIIA was 6.7% (p < 0.001). Of note, the prevalence of brain-limited metastases was approximately 6% for both summary stages II and III.

Conclusions

Considering the similarity in prevalence of isolated brain metastases and the potential hazards associated with brain imaging in early stage NSCLC, practitioners may consider a more liberal use of brain imaging when interpreting conflicting guidelines.

Incidence and Prognosis Nomogram of Small Solitary Lung Cancer (≤2 cm) With Extra-Thoracic Metastasis at Initial Diagnosis:A Population-Based Study

BACKGROUND

Small solitary lung cancer (≤2 cm) with extra-thoracic metastasis and no nodal metastasis or intra-thoracic metastasis is a rare situation in clinic.

METHODS

Lung cancer patients with stage T1aN0M0 and T1aN0M1b from 2010 to 2015 were identified from the Surveillance, Epidemiology, and End Results database. The identified significant parameters were utilized to develop 2 nomogram to predict the extra-thoracic metastasis rates and the overall survival for the group of patients with stage T1aN0M1b.

RESULTS

Small solitary lung cancers which occur in the males, younger patients, or locate in the main bronchus or left lung, or with histologic type as small cell lung cancer, or with undifferentiated type, tend to have extra-thoracic metastasis. Application of the nomogram in the intra-group still gave good discrimination and good calibration. Univariable and multivariable analysis identified several clinical data as the prognostic factors for lung cancer patients with stage T1aN0M1b, all the factors above were incorporated into the nomogram. ROC curve analysis showed that the nomogram had good discrimination, with AUC of .779, .786 and .77 for 1-, 3- and 5-year survival in the development group and validation group, respectively. Moreover, decision curve analysis has been implemented to evaluate and compare prediction and prognostic nomogram.

CONCLUSIONS

Younger male patients whose lung cancer locates in main bronchus or left lung, or with undifferentiated type, or with histologic type as small cell lung cancer are more likely to have extra-thoracic metastasis. The proposed nomogram reliably predicted OS for lung cancer patients with stage T1aN0M1b, though further validation is needed, it may be a useful tool in clinical practice. These models can be wildly used for easy facilitate the lung cancer individualized prediction of extra-thoracic metastasis and OS.

Overuse of Diagnostic Brain Imaging Among Patients With Stage IA Non-Small Cell Lung Cancer

BACKGROUND

Among patients diagnosed with stage IA non-small cell lung cancer (NSCLC), the incidence of occult brain metastasis is low, and several professional societies recommend against brain imaging for staging purposes. The goal of this study was to characterize the use of brain imaging among Medicare patients diagnosed with stage IA NSCLC.

METHODS

Using data from linked SEER-Medicare claims, we identified patients diagnosed with AJCC 8th edition stage IA NSCLC in 2004 through 2013. Patients were classified as having received brain imaging if they underwent head CT or brain MRI from 1 month before to 3 months after diagnosis. We identified factors associated with receipt of brain imaging using multivariable logistic regression.

RESULTS

Among 13,809 patients with stage IA NSCLC, 3,417 (25%) underwent brain imaging at time of diagnosis. The rate of brain imaging increased over time, from 23.5% in 2004 to 28.7% in 2013 (P=.0006). There was significant variation in the use of brain imaging across hospital service areas, with rates ranging from 0% to 64.0%. Factors associated with a greater likelihood of brain imaging included older age (odds ratios [ORs] of 1.16 for 70-74 years, 1.13 for 75-79 years, 1.31 for 80-84 years, and 1.46 for ≥85 years compared with 65-69 years; all P<.05), female sex (OR, 1.09; P<.05), black race (OR 1.23; P<.05), larger tumor size (ORs of 1.23 for 11-20 mm and 1.28 for 21-30 mm tumors vs 1-10 mm tumors; all P<.05), and higher modified Charlson-Deyo comorbidity score (OR, 1.28 for score >1 vs score of 0; P<.05).

CONCLUSIONS

Roughly 1 in 4 patients with stage IA NSCLC received brain imaging at the time of diagnosis despite national recommendations against the practice. Although several patient factors are associated with receipt of brain imaging, there is significant geographic variation across the United States. Closer adherence to clinical guidelines is likely to result in more cost-effective care.

Overuse of follow-up chest computed tomography in patients with incidentally identified nodules suspicious for lung cancer

PURPOSE

Although professional societies agreed that CT screening inconsistent with recommendation leads to radiation-related cancer and unexpected cost, many patients still undergo unnecessary Chest CT before treatment. The goal of this study was to assess the overuse of Chest CT in different type of patients.

METHODS

Data on 1853 patients who underwent pulmonary resection from May 2019 to May 2020 were retrospectively analyzed. Data collected include age, sex, follow-up period, density and size of nodules and frequency of undergoing Chest CT. Pearson χ² test and logistic regression were conducted to compare the receipt of CT screening.

RESULTS

Among 1853 patients in the study, 689 (37.2%) overused Chest CT during follow-up of the pulmonary nodules. This rate was 16.2% among patients with solid nodules, 57.5% among patients with pure ground glass opacity (pGGO), and 41.4% among patients with mixed ground glass opacity (mGGO) (P < 0.001). 50.7% in the "age ≤ 40" group, 39.8% in the "41 ≤ age ≤ 50" group, 38.7% in the "51 ≤ age ≤ 60" group, 32.3% in the "61 ≤ age ≤ 70" group, 27.8% in the " > 70" group underwent unnecessary CT (P < 0.001). Female got more unnecessary CT than male (40.6% vs 32.8%, P < 0.001). Factors associated with a greater likelihood of overusing Chest CT was the density of nodules [odds ratios (ORs) of 0.53 for mGGO; 0.15 for solid nodule, P < 0.0001, vs patients with pGGO].

CONCLUSION

Roughly 37% patients with pulmonary nodules received Chest CT too frequently despite national recommendations against the practice. Closer adherence to clinical guidelines is likely to result in more cost-effective care.

Significance of Brain Imaging for Staging in Patients With Clinical Stage T1-2 N0 Non-Small-Cell Lung Cancer on Positron Emission Tomography/Computed Tomography

BACKGROUND

Routine positron emission tomography/computed tomography (PET/CT) has been recommended even for clinical stage I non-small-cell lung cancer (NSCLC). In spite of the progress in the screening procedure, and revisions to TNM classification, there is no evidence to support brain imaging screening of patients assessed with the current staging protocol including PET/CT.

MATERIALS AND METHODS

We retrospectively investigated the frequency of extrathoracic metastasis in 466 consecutive patients with clinical stage T1-2 N0 NSCLC with the complete staging assessment comprised of thin-section CT, PET/CT, and brain contrast-enhanced magnetic resonance imaging between 2008 and 2016. All patients were reclassified according to the eighth edition of the tumor, node, and metastasis (TNM) classification.

RESULTS

Among all patients, 70% of the tumors were pure solid and 30% had part-solid ground-glass opacity on thin-section CT, and 388 (83%) and 78 (17%) were classified into clinical stages T1 and T2, respectively. Eight patients (1.7%) had extrathoracic metastasis, including 3 (0.6%) with brain metastasis, and all showed pure-solid tumors. The frequency of extrathoracic and brain metastasis was 1.0% and 0.5% in 388 T1 patients, and 5.0% and 3.0% in 78 T2 patients. Although brain metastases were detected in 2 of 7 patients (29%) with PET/CT detectable extrathoracic metastases and 1 of 459 patients (0.2%) without PET/CT detectable extrathoracic metastasis, there were no neurologically asymptomatic brain metastases in patients with early-stage NSCLC confirmed by PET/CT.

CONCLUSION

Routine screening of brain imaging is unnecessary in patients with early-stage NSCLC, assessed with the current staging protocol including PET/CT.

Impact of Low-Dose Computed Tomography Screening for Primary Lung Cancer on Subsequent Risk of Brain Metastasis

INTRODUCTION

Brain metastasis (BM) is one of the most common metastases from primary lung cancer (PLC). Recently, the National Lung Screening Trial revealed the efficacy of low-dose computed tomography (LDCT) screening on LC mortality reduction. Nevertheless, it remains unknown if early detection of PLC through LDCT may be potentially beneficial in reducing the risk of subsequent metastases. Our study aimed to investigate the impact of LDCT screening for PLC on the risk of developing BM after PLC diagnosis.

METHODS

We used the National Lung Screening Trial data to identify 1502 participants who were diagnosed with PLC in 2002 to 2009 and have follow-up data for BM. Cause-specific competing risk regression was applied to evaluate an association between BM risk and the mode of PLC detection-that is, LDCT screen-detected versus non-LDCT screen-detected. Subgroup analyses were conducted in patients with early stage PLC and those who underwent surgery for PLC.

RESULTS

Of 1502 participants, 41.4% had PLC detected through LDCT screening versus 58.6% detected through other methods, for example, chest radiograph or incidental detection. Patients whose PLC was detected with LDCT screening had a significantly lower 3-year incidence of BM (6.5%) versus those without (11.9%), with a cause-specific hazard ratio (HR) of 0.53 (p = 0.001), adjusting for age at PLC diagnosis, PLC stage, PLC histology, and smoking status. This significant reduction in BM risk among PLCs detected through LDCT screening persisted in subgroups of participants with early stage PLC (HR = 0.47, p = 0.002) and those who underwent surgery (HR = 0.37, p = 0.001).

CONCLUSIONS

Early detection of PLC using LDCT screening is associated with lower risk of BM after PLC diagnosis on the basis of a large population-based study.

Differentiation of brain metastases from small and non-small lung cancers using apparent diffusion coefficient (ADC) maps

BACKGROUND

Brain metastases are particularly common in patients with small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), with NSCLC showing a less  aggressive clinical course and lower chemo- and radio sensitivity compared to SCLC. Early adequate therapy is highly desirable and depends on a reliable classification of tumor type. The apparent diffusion coefficient is a noninvasive neuroimaging marker with the potential to differentiate between major histological subtypes. Here we determine the sensitivity and specificity of the apparent diffusion coefficient to distinguish between NSCLC and SCLC.

METHODS

We enrolled all NSCLC and SCLC patients diagnosed between 2008 and 2019 at the University Medical Center Göttingen. Cranial MR scans were visually inspected for brain metastases and the ratio of the apparent diffusion coefficient (ADC) was calculated by dividing the ADC measured within the solid part of a metastasis by a reference ADC extracted from an equivalent region in unaffected tissue on the contralateral hemisphere.

RESULTS

Out of 411 enrolled patients, we detected 129 patients (83 NSCLC, 46 SCLC) with sufficiently large brain metastases with histologically classified lung cancer and no hemorrhage. We analyzed 185 brain metastases, 84 of SCLC and 101 of NSCLC. SCLC brain metastases showed an ADC ratio of 0.68 ± 0.12 SD, and NSCLC brain metastases showed an ADC ratio of 1.47 ± 0.31 SD. Receiver operating curve statistics differentiated brain metastases of NSCLC from SCLC with an area under the curve of 0.99 and a 95% CI of 0.98 to 1, p < 0.001. Youden's J cut-point is 0.97 at a sensitivity of 0.989 and a specificity of 0.988.

CONCLUSIONS

In patients with lung cancer and brain metastases with solid tumor parts, ADC ratio enables an ad hoc differentiation of SCLC and NSCLC, easily achieved during routine neuroradiological examination. Non-invasive MR imaging enables an early-individualized management of brain metastases from lung cancer.

TRIAL REGISTRATION

The study was registered in the German Clinical Trials Register (DRKS00023016).

The effect of diagnostic assessment programs on the diagnosis and treatment of patients with lung cancer in Ontario, Canada

INTRODUCTION

Diagnostic assessment programs (DAPs) were implemented in Ontario, Canada, to improve the efficiency of the lung cancer care continuum. We compared the efficiency and effectiveness of care provided to patients in DAPs relative to usual care (non-DAPs).

METHODS

Lung cancer patients diagnosed between 2014 and 2016 were identified from the Ontario Cancer Registry. Using administrative databases, we identified various health-care encounters 6 months before diagnosis until the start of treatment and compared utilization patterns, timing, and overall survival between DAP and non-DAP patients.

RESULTS

DAP patients were younger (P < 0.0001), had fewer comorbidities (P = 0.0006), and were more likely to have early-stage disease (36% vs. 25%) than non-DAP patients. Although DAP patients had a similar time until diagnosis as non-DAP patients, the time until treatment was 8.5 days shorter for DAP patients. DAP patients were more likely to receive diagnostic tests and specialist consultations and less likely to have duplicate chest imaging. DAP patients were more likely to receive brain imaging. Among early-stage lung cancers, brain imaging was high (74% for DAP and 67% for non-DAP), exceeding guideline recommendations. After adjustment for clinical and demographic factors, DAP patients had better overall survival than non-DAP patients (hazard ratio [HR]: 0.79 [0.76-0.82]), but this benefit was lost after adjusting for emergency presentation (HR: 0.96 [0.92-1.00]). A longer time until treatment was associated with better overall survival.

CONCLUSION

DAPs provided earlier treatment and better access to care, potentially improving survival. Quality improvement opportunities include reducing unnecessary or duplicate testing and characterizing patients who are diagnosed emergently.

Incidence and real-world burden of brain metastases from solid tumors and hematologic malignancies in Ontario: a population-based study

BACKGROUND

Although intracranial metastatic disease (IMD) is a frequent complication of cancer, most cancer registries do not capture these cases. Consequently, a data-gap exists, which thwarts system-level quality improvement efforts. The purpose of this investigation was to determine the real-world burden of IMD.

METHODS

Patients diagnosed with a non-CNS cancer between 2010 and 2018 were identified from the Ontario Cancer Registry. IMD was identified by scanning hospital administrative databases for cranial irradiation or coding for a secondary brain malignancy (ICD-10 code C793).

RESULTS

25,478 of 601,678 (4.2%) patients with a diagnosis of primary cancer were found to have IMD. The median time from primary cancer diagnosis to IMD was 5.2 (0.7, 15.4) months and varied across disease sites, for example, 2.1 months for lung, 7.3 months for kidney, and 22.8 months for breast. Median survival following diagnosis with IMD was 3.7 months. Lung cancer accounted for 60% of all brain metastases, followed by breast cancer (11%) and melanoma (6%). More advanced stage at diagnosis and younger age were associated with a higher likelihood of developing IMD (P < .0001). IMD was also associated with triple-negative breast cancers and ductal histology (P < .001), and with small-cell histology in patients with lung cancer (P < .0001). The annual incidence of IMD was 3,520, translating to 24.2 per 100,000 persons.

CONCLUSION

IMD represents a significant burden in patients with systemic cancers and is a significant cause of cancer mortality. Our findings support measures to actively capture incidents of brain metastasis in cancer registries.

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.

Pre-diagnosis Multidisciplinary Tumor Board and Time to Staging in Lung Cancer: The Case Western MetroHealth Experience

Introduction

National guidelines support the discussion of cancer patients by multidisciplinary tumor boards (MTB). We researched whether early pre-diagnosis multidisciplinary tumor board discussions are associated with shorter times to staging in lung cancer.

Methods

We reviewed our institution’s lung cancer and MTB registries to retrospectively study if an early discussion at pre-diagnostic MTB (pd-MTB) influenced the timeliness of diagnostic evaluation. Over 14 months, 161 consecutive patients with a diagnosis of lung cancer were included. Fifty-five patients were presented at pd-MTB while 106 (controls) patients were not. The primary outcome was the difference in the time interval from suspicious imaging (Ix) to completion of staging (Sx). Outcomes were adjusted for key confounders with a multiple regression analysis.

Results

For stages I, II, and III lung cancer, where time to therapy matters, early discussion of patients with nodules suspicious for malignancy at pd-MTB was associated with no time delays when compared to patients who were not discussed in pd-MTB. The mean time intervals for imaging to staging (with standard deviations) are 65 days in controls (sd = 42.67) and 75 days (sd = 58.27) in tumor board cases (p=0.39). Adjusting for confounders with a multiple regression analysis among all stages revealed a similar lack of difference in time intervals to diagnosis, staging, and therapy.

Conclusion

Our stage I-III lung cancer cases (pd-MTB) completed staging in a timely manner, similar to controls (no pd-MTB). The severity of illness at presentation and the availability of diagnostic services and others likely influence the results. Our manuscript shares important numerical data on timelines during cancer diagnosis and treatment. Using this data, prospective registries examining the process workflow may help standardize cancer quality goals and maximize referrals from primary-care/specialty providers. The key findings in our study create a paradigm for future studies to create and achieve “door-to-balloon” time targets for lung cancer care (akin to cardiac care) across different styles of tumor boards.

Utility of FDG PET/CT for Preoperative Staging of Non-Small Cell Lung Cancers Manifesting as Subsolid Nodules With a Solid Portion of 3 cm or Smaller

OBJECTIVE. The objective of our study was to investigate the utility of FDG PET/CT for the preoperative staging of subsolid non-small cell lung cancers (NSCLCs) with a solid portion size of 3 cm or smaller. MATERIALS AND METHODS. We retrospectively enrolled 855 patients with pathologically proven NSCLCs manifesting as subsolid nodules with a solid portion of 3 cm or smaller on CT. We then compared the diagnostic performances of FDG PET/CT and chest CT for detecting lymph node (LN), intrathoracic, or distant metastases in patients who underwent preoperative chest CT and FDG PET/CT. After propensity score matching, we compared the diagnostic performance of FDG PET/CT in the group who underwent both chest CT and FDG PET/CT with that of chest CT in patients who did not undergo FDG PET/CT. RESULTS. There were LN metastases in 25 of 765 patients (3.3%) who underwent surgical LN dissection or biopsy and intrathoracic or distant metastasis in two of 855 patients (0.2%). For LN staging, FDG PET/CT showed a sensitivity of 44.0%, specificity of 81.5%, positive predictive value of 9.6%, negative predictive value of 97.0%, and accuracy of 79.9%, which were lower than those of chest CT for accuracy (p < 0.0001). FDG PET/CT could not accurately detect any intrathoracic or distant metastasis. After propensity score matching, the diagnostic accuracy for LN staging of FDG PET/CT in the group who underwent both CT and FDG PET/CT was lower than that of chest CT in the group who did not undergo FDG PET/CT (p = 0.002), and the diagnostic accuracy for intrathoracic and distant metastases was not different (p > 0.999). CONCLUSION. FDG PET/CT has limited utility in preoperatively detecting LN or distant metastasis in patients with subsolid NSCLCs with a solid portion size of 3 cm or smaller.

CT-Based Radiomics Model for Predicting Brain Metastasis in Category T1 Lung Adenocarcinoma

OBJECTIVE. The purpose of this study is to develop and evaluate an unenhanced CT-based radiomics model to predict brain metastasis (BM) in patients with category T1 lung adenocarcinoma. MATERIALS AND METHODS. A total of 89 eligible patients with category T1 lung adenocarcinoma were enrolled and classified as patients with BM (n = 35) or patients without BM (n = 54). A total of 1160 quantitative radiomic features were extracted from unenhanced CT images of each patient. Three prediction models (the clinical model, the radiomics model, and a hybrid [clinical plus radiomics] model) were established. The ROC AUC value and 10-fold cross-validation were used to evaluate the prediction performance of the models. RESULTS. In terms of predictive performance, the mean AUC value was 0.759 (95% CI, 0.643-0.867; sensitivity, 82.9%; specificity, 57.4%) for the clinical model, 0.847 (95% CI, 0.739-0.915; sensitivity, 80.0%; specificity, 81.5%) for the radiomics model, and 0.871 (95% CI, 0.767-0.933; sensitivity = 82.9%, specificity = 83.3%) for the hybrid model. The hybrid and radiomics models (p = 0.0072 and 0.0492, respectively) performed significantly better than the clinical model. No significant difference was found between the radiomics model and the hybrid model (p = 0.1022). CONCLUSION. A CT-based radiomics model presented good predictive performance and great potential for predicting BM in patients with category T1 lung adenocarcinoma. As a promising adjuvant tool, it can be helpful for guiding BM screening and thus benefiting personalized surveillance for patients with lung cancer.

Preoperative brain MRI for clinical stage IA lung cancer: is routine scanning rational?

PURPOSE

Early detection and control of lung cancer brain metastases (BMs) are important. However, several guideline recommendations are inconsistent with regard to routine preoperative brain MRI, especially in patients with clinical stage IA lung cancer. Our study evaluated the value of preoperative brain MRI in patients with clinical stage IA lung cancer.

METHODS

A retrospective analysis of patients with lung cancer was performed using a prospectively collected database. Clinical data and the results of brain MRI were collected and analyzed.

RESULTS

Patients with pathologically proved primary lung cancer who underwent an MRI at initial diagnosis were identified (3392 patients). In total, 170 patients (5.0%) were diagnosed with BMs. The increased frequency of BMs was significantly associated with advanced clinical stage (P = 0.000) and pathological type (P = 0.011). BMs were detected in 11 out of 1595 patients with clinical stage IA lung cancer (0.7%). BMs were more common in patients with clinical stage cT1c lung cancer (1.9%) than those with clinical stage cT1a or cT1b (0.1%, odds ratio = 21.30, 95% confidence interval: 2.7-166.9, P = 0.000). All patients with stage IA lung cancer and BMs had solid lung lesions (P = 0.002).

CONCLUSIONS

Preoperative brain MRI might help identify BMs in patients with lung cancer that has progressed beyond stage IA. In patients with clinical stage IA lung cancer, we do not recommend preoperative brain MRI, but it may potentially be beneficial in those with solid T1c cancers.

Incidence of brain metastasis in lung adenocarcinoma at initial diagnosis on the basis of stage and genetic alterations

OBJECTIVE

Patients with lung adenocarcinoma (ADC) are at higher risk of the development of brain metastasis (BM), and genetic alterations are associated with BM.

PATIENTS AND METHODS

A total of 598 patients with lung ADC in our institution between January 2014 and December 2014 were reviewed retrospectively. We evaluated the incidence of BM by stage and genetic alterations.

RESULTS

Of the 598 patients, 97 (16.2%) had BM, which occurred across all stages. The incidence of BM showed a tendency to increase as the stage increased (p < 0.001, trend test). Although patients with EGFR mutations had BM across all stages, those with ALK or K- mutations had BM only in stage III and IV diseases. Regardless of types of mutations, the incidence of BM showed a tendency to increase as the T or N staging increased (p < 0.001 for each of EGFR, ALK, and K-RAS mutations, trend test). Whereas BM incidence showed a tendency to increase as the M staging increased in patients with EGFR-mutant lung ADC (p < 0.001, trend test), there was no linear trend between M staging and ALK (p = 0.469, trend test) or K-RAS mutations (p = 0.066, trend test). After adjusting covariables, EGFR mutations were associated with BM in never-smokers (adjusted OR = 2.07, 95% CI = 1.02-4.34) and K-RAS mutations were risk factors for BM in males (adjusted OR = 3.86, 95% CI = 1.01-14.43).

CONCLUSIONS

BM occurred in approximately 16% of lung ADC patients, including 3% with stage I diseases. Whereas EGFR-mutant lung ADC had BM across all stages, ALK- or K-RAS-mutant lung ADC had BM only in advanced stages. EGFR mutations were risk factors for BM among never-smokers and K-RAS mutations were risk factors among males.

Lymph Node Size Predicts for Asymptomatic Brain Metastases in Patients With Non-small-cell Lung Cancer at Diagnosis

BACKGROUND

We questioned whether the National Comprehensive Cancer Network recommendations for brain magnetic resonance imaging (MRI) for patients with stage ≥ IB non-small-cell lung cancer (NSCLC) was high-yield compared with American College of Clinical Pharmacy and National Institute for Health and Care Excellence guidelines recommending stage III and above NSCLC. We present the prevalence and factors predictive of asymptomatic brain metastases at diagnosis in patients with NSCLC without extracranial metastases.

MATERIALS AND METHODS

A retrospective analysis of 193 consecutive, treatment-naïve patients with NSCLC diagnosed between January 2010 and August 2015 was performed. Exclusion criteria included no brain MRI staging, symptomatic brain metastases, or stage IV based on extracranial disease. Univariate and multivariate logistic regression was performed.

RESULTS

The patient characteristics include median age of 65 years (range, 36-90 years), 51% adenocarcinoma/36% squamous carcinoma, and pre-MRI stage grouping of 31% I, 22% II, 34% IIIA, and 13% IIIB. The overall prevalence of brain metastases was 5.7% (n = 11). One (2.4%) stage IA and 1 (5.6%) stage IB patient had asymptomatic brain metastases at diagnosis, both were adenocarcinomas. On univariate analysis, increasing lymph nodal stage (P = .02), lymph nodal size > 2 cm (P = .009), multi-lymph nodal N1/N2 station involvement (P = .027), and overall stage (P = .005) were associated with asymptomatic brain metastases. On multivariate analysis, increasing lymph nodal size remained significant (odds ratio, 1.545; P = .009).

CONCLUSION

Our series shows a 5.7% rate of asymptomatic brain metastasis for patients with stage I to III NSCLC. Increasing lymph nodal size was the only predictor of asymptomatic brain metastases, suggesting over-utilization of MRI in early-stage disease, especially in lymph node-negative patients with NSCLC. Future efforts will explore the utility of baseline MRI in lymph node-positive stage II and all stage IIIA patients.

Choosing wisely in oncology: necessity and obstacles

In the last decades, the survival of many patients with cancer improved thanks to modern diagnostic methods and progresses in therapy. Still for several tumours, especially when diagnosed at an advanced stage, the benefits of treatment in terms of increased survival or quality of life are at best modest when not marginal, and should be weighed against the potential discomfort caused by medical procedures. As in other specialties, in oncology as well the dialogue between doctor and patient should be encouraged about the potential overuse of diagnostic procedures or treatments. Several oncological societies produced recommendations similar to those proposed by other medical disciplines adhering to the Choosing Wisely (CW) campaign. In this review, we describe what was reported in the medical literature concerning adequacy of screening, diagnostic, treatment and follow-up procedures and the potential impact on them of the CW. We only marginally touch on the more complex topic of treatment appropriateness, for which several evaluation methods have been developed (including the European Society for Medical Oncology-magnitude of clinical benefit scale). Finally, we review the possible obstacles for the development of CW in the oncological setting and focus on the strategies which could allow CW to evolve in the cancer field, so as to enhance the therapeutic relationship between medical professionals and patients and promote more appropriate management.

Dilemmas in Lung Cancer Staging

The advent of the 8th edition of the lung cancer staging system reflects a further meticulous evidence-based advance in the stratification of the survival of patients with lung cancer. Although addressing many limitations of earlier staging systems, several limitations in staging remain. This article reviews from a radiological perspective the limitations of the current staging system, highlighting the process of TNM restructuring, the residual issues with regards to the assignment of T, N, M descriptors, and their associated stage groupings and how these dilemmas impact guidance of multidisciplinary teams taking care of patients with lung cancer.

Early stage non-small cell lung cancer patients need brain imaging regardless of symptoms

BACKGROUND

Japanese Lung Cancer Society and ESMO guideline recommends screening for brain metastasis in all patients with non-small cell lung cancer (NSCLC), while NCCN/ACCP guidelines do not recommend screening patients who are asymptomatic and with clinical stage I NSCLC. However, brain metastasis sometimes occurs in early stage NSCLC patients without any neurological symptoms.

METHODS

We retrospectively reviewed medical records of 124 patients admitted to the University of Tokyo Hospital with stage IV NSCLC from January 2012 to April 2016. We analyzed clinical stage, the presence of the central nervous system manifestations and the number of brain metastases.

RESULTS

Forty-six out of 124 cases had brain metastasis at presentation. The brain metastasis group had larger number of female, never smokers and patients with EGFR mutation compared with extracranial metastasis group. Twenty-one of 35 adenocarcinoma cases with brain metastasis had EGFR mutations. Out of 46 brain metastasis patients, 29 patients (63%) were asymptomatic and patients with EGFR mutations were significantly less likely to have neurological symptoms (4/21 vs. 7/14, p = 0.049). Six out of 46 cases with brain metastasis (13%) were clinical T1-2aN0. In clinical T1-2aN0 cases, only one patient had neurological symptoms at presentation.

CONCLUSION

In clinical T1-2aN0 lung cancer patients with brain metastasis, almost all patients were asymptomatic. Patients with EGFR mutations and brain metastasis were likely to be asymptomatic. Regardless of central nervous system symptoms, routine brain imaging seems warranted in all NSCLC patients, especially in areas where patients have a higher frequency of EGFR mutations.

Brain imaging before primary lung cancer resection: a controversial topic

Objective

International and national recommendations for brain imaging in patients planned to undergo potentially curative resection of non-small-cell lung cancer (NSCLC) are variably implemented throughout the United Kingdom [Hudson BJ, Crawford MB, and Curtin J et al (2015) Brain imaging in lung cancer patients without symptoms of brain metastases: a national survey of current practice in EnglandClin Radiol https://doi.org/10.1016/j.crad.2015.02.007]. However, the recommendations are not based on high-quality evidence and do not take into account cost implications and local resources. Our aim was to determine local practice based on historic outcomes in this patient cohort.

Methods

This retrospective study took place in a regional thoracic surgical centre in the United Kingdom. Pathology records for all patients who had undergone lung resection with curative intent during the time period January 2012–December 2014 were analysed in October 2015. Electronic pathology and radiology reports were accessed for each patient and data collected about their histological findings, TNM stage, resection margins, and the presence of brain metastases on either pre-operative or post-operative imaging. From the dates given on imaging, we calculated the number of days post-resection that the brain metastases were detected.

Results

585 patients were identified who had undergone resection of their lung cancer. Of these, 471 had accessible electronic radiology records to assess for the radiological evidence of brain metastases. When their electronic records were evaluated, 25/471 (5.3%) patients had radiological evidence of brain metastasis. Of these, five patients had been diagnosed with a brain metastasis at initial presentation and had undergone primary resection of the brain metastasis followed by resection of the lung primary. One patient had been diagnosed with both a primary lung and a primary bowel adenocarcinoma; on review of the case, it was felt that the brain metastasis was more likely to have originated from the bowel cancer. One had been clinically diagnosed with a cerebral abscess while the radiology had been reported as showing a metastatic deposit. Of the remaining 18/471 (3.8%) patients who presented with brain metastases after their surgical resection, 12 patients had adenocarcinoma, four patients had squamous cell carcinoma, one had basaloid, and one had large-cell neuroendocrine. The mean number of days post-resection that the brain metastases were identified was 371 days, range 14–1032 days, median 295 days (date of metastases not available for two patients).

Conclusion

The rate of brain metastases identified in this study was similar to previous studies. This would suggest that preoperative staging of the central nervous system may change the management pathway in a small group of patients. However, for this group of patients, the change would be significant either sparing them non-curative surgery or allowing aggressive management of oligometastatic disease. Therefore, we would recommend pre-operative brain imaging with MRI for all patients undergoing potentially curative lung resection.