The significance of visceral pleural surface invasion in 321 cases of non-small cell lung cancers with pleural retraction

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.

Upstaged from cT1a-c to pT2a lung cancer, related to visceral pleural invasion patients, after segmentectomy: is it an indication to complete resection to lobectomy?

OBJECTIVES

Segmentectomy may be indicated for T1a-cN0 non-small-cell lung cancer. However, several patients are upstaged pT2a at final pathological examination due to visceral pleural invasion (VPI). As resection is usually not completed to lobectomy, this may raise issue of potential worse prognosis. The aim of this study is to compare prognosis of VPI upstaged cT1N0 patients operated on by segmentectomy or lobectomy.

METHODS

Data of patients from 3 centres were analysed. This was a retrospective study, of patients operated on from April 2007 to December 2019. Survival and recurrence were assessed by Kaplan-Meier method and cox regression analysis.

RESULTS

Lobectomy and segmentectomy were performed in 191 (75.4%) and in 62 (24.5%) patients, respectively. No difference in 5-year disease-free survival rate between lobectomy (70%) and segmentectomy (64.7%) was observed. There was no difference in loco-regional recurrence, nor in ipsilateral pleural recurrence. The distant recurrence rate was higher (P = 0.027) in the segmentectomy group. Five-year overall survival rate was similar for both lobectomy (73%) and segmentectomy (75.8%) groups. After propensity score matching, there was no difference in 5-year disease-free survival rate (P = 0.27) between lobectomy (85%) and segmentectomy (66.9%), and in 5-year overall survival rate (P = 0.42) between the 2 groups (lobectomy 76.3% vs segmentectomy 80.1%). Segmentectomy was not impacting neither recurrence, nor survival.

CONCLUSIONS

Detection of VPI (pT2a upstage) in patients who underwent segmentectomy for cT1a-c non-small-cell lung cancer does not seem to be an indication to extend resection to lobectomy.

Tumour-pleura relationship on CT is a risk factor for occult lymph node metastasis in peripheral clinical stage IA solid adenocarcinoma

OBJECTIVES

To investigate whether the tumour-pleura relationship on computed tomography (CT) is a risk factor for occult lymph node metastasis (OLNM) in peripheral clinical stage IA solid adenocarcinoma.

METHODS

A total of 232 patients were included in the study. The tumour-pleura relationship was divided into four types: type 1, the tumour was unrelated to the pleura; type 2, the tumour was not in contact with the pleura, and one or more linear or striated pleural tags were visible; type 3, the tumour was not in contact with the pleura, and one or more linear or striated pleural tags with soft tissue component at the pleural end were visible; and type 4, the tumour was in contact with the pleura. Univariate and multivariate logistic regression analyses were used to identify the predictive factors, including the tumour-pleura relationship, clinical factors, conventional CT findings, and pathology-reported visceral pleural invasion, for OLNM.

RESULTS

Type 3 and 4 tumour-pleura relationships were more likely to have visceral pleural invasion than type 1 and 2 tumour-pleura relationships (p < 0.001). Univariate and multivariate logistic regression analyses revealed that the type 3 or 4 tumour-pleura relationship (OR: 3.261, p = 0.026), carcinoembryonic antigen level (OR: 3.361, p = 0.006), cytokeratin 19 fragments level (OR: 2.539, p = 0.025), and mediastinal window tumour size (OR: 1.078, p = 0.020) were predictive factors for OLNM.

CONCLUSIONS

The type 3 or 4 tumour-pleura relationship is correlated with a greater risk of OLNM in peripheral clinical stage IA solid adenocarcinoma.

KEY POINTS

• The tumour-pleura relationship on CT is a risk factor for occult lymph node metastasis in peripheral clinical stage IA solid adenocarcinoma. • Other risk factors for OLNM include CEA level, CYFRA level, and mediastinal window tumour size. • Pathology-reported visceral pleural invasion is not a risk factor for OLNM.

Prognostic relevance of pleural invasion for resected NSCLC patients undergoing adjuvant treatments: A propensity score-matched analysis of SEER database

BACKGROUND

Adjuvant chemotherapy demonstrated a clear benefit in resected non-small cell lung cancer (NSCLC) with nodal disease (stages II-III), and a minimal benefit in tumors >4 cm (stage II, TNM 8th edition). Pleural invasion (PL), classified as visceral pleural invasion (VPI, which includes PL1 and PL2, and parietal pleural invasion (PL3), is an established negative prognostic factor. However, whether PL should influence the decisional algorithm of postoperative chemotherapy is controversial.

METHODS

A survival analysis of NSCLC patients who underwent radical surgery between 2010 and 2015 included in the SEER database was performed. Tumor stage and size, number of examined and positive nodes, histology, PL, and treatment data were extracted. Propensity score matching was performed. The benefit of chemotherapy was analyzed in two subgroups: standard of care (SOC), including patients with positive nodes or tumors ≥ 4 cm; non-SOC, including patients with tumors < 4 cm and negative nodes.

RESULTS

Records of 30,858 patients were extracted. 11,708 patients were included in the propensity score-matched analysis. In the SOC subgroup, including 8089 patients, all pleural invasion degrees were associated with progressively increased risk for death and shorter overall survival (OS), independently from chemotherapy administration. However, chemotherapy significantly improved the median OS regardless of the extent of PL. In the non-SOC subgroup, including 3619 patients, only PL3 was associated with increased mortality. The administration of chemotherapy did not improve survival outcomes.

CONCLUSION

Chemotherapy should be strongly recommended in patients in the SOC-subgroup with pleural invasion. VPI is not associated with unfavorable prognosis in the non-SOC subgroup.

Development and Validation of a Combined Model for Preoperative Prediction of Lymph Node Metastasis in Peripheral Lung Adenocarcinoma

Background

Based on the “seed and soil” theory proposed by previous studies, we aimed to develop and validate a combined model of machine learning for predicting lymph node metastasis (LNM) in patients with peripheral lung adenocarcinoma (PLADC).

Methods

Radiomics models were developed in a primary cohort of 390 patients (training cohort) with pathologically confirmed PLADC from January 2016 to August 2018. The patients were divided into the LNM (−) and LNM (+) groups. Thereafter, the patients were subdivided according to TNM stages N0, N1, N2, and N3. Radiomic features from unenhanced computed tomography (CT) were extracted. Radiomic signatures of the primary tumor (R1) and adjacent pleura (R2) were built as predictors of LNM. CT morphological features and clinical characteristics were compared between both groups. A combined model incorporating R1, R2, and CT morphological features, and clinical risk factors was developed by multivariate analysis. The combined model’s performance was assessed by receiver operating characteristic (ROC) curve. An internal validation cohort containing 166 consecutive patients from September 2018 to November 2019 was also assessed.

Results

Thirty-one radiomic features of R1 and R2 were significant predictors of LNM (all P < 0.05). Sex, smoking history, tumor size, density, air bronchogram, spiculation, lobulation, necrosis, pleural effusion, and pleural involvement also differed significantly between the groups (all P < 0.05). R1, R2, tumor size, and spiculation in the combined model were independent risk factors for predicting LNM in patients with PLADC, with area under the ROC curves (AUCs) of 0.897 and 0.883 in the training and validation cohorts, respectively. The combined model identified N0, N1, N2, and N3, with AUCs ranging from 0.691–0.927 in the training cohort and 0.700–0.951 in the validation cohort, respectively, thereby indicating good performance.

Conclusion

CT phenotypes of the primary tumor and adjacent pleura were significantly associated with LNM. A combined model incorporating radiomic signatures, CT morphological features, and clinical risk factors can assess LNM of patients with PLADC accurately and non-invasively.

Correlation between pleural tags on CT and visceral pleural invasion of peripheral lung cancer that does not appear touching the pleural surface

OBJECTIVES

To evaluate the association between a sign and visceral pleural invasion (VPI) of peripheral non-small-cell lung cancer (NSCLC) that does not appear touching the pleural surface.

METHODS

A total of 221 consecutive patients with NSCLC that did not appear touching the pleural surface, ≤ 3 cm in solid tumor diameter, and was surgically resected between January 2009 and December 2015 were included. We focused on the flat distortion of the tumor caused by an arch-shaped linear tag between the tumor and the pleura on CT and named it a bridge tag sign. We evaluated the associations between the clinicopathological features of the tumor, including the bridge tag sign, and VPI. We also evaluated the associations between histopathological findings and the bridge tag sign. The utility of the bridge tag sign in the diagnosis of VPI was statistically assessed.

RESULTS

The bridge tag sign was observed in 48 (20.8%) patients. VPI was positive in 9 (4.1%) patients; among these, the bridge tag sign was positive in 8 patients. In multivariate analysis, a bridge tag sign was significantly associated with VPI. The bridge tag sign was associated with longer contact length of the pleura with the tumor and trapezoid type pleural retraction. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of VPI were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively.

CONCLUSIONS

A bridge tag sign on CT might improve the accuracy of the prediction of VPI.

KEY POINTS

• We present the bridge tag sign which is defined as a flat distortion of an NSCLC tumor by an arch-shaped linear tag between the tumor and chest wall or interlobar fissure. • The bridge tag sign was an independent predictive factor for visceral pleural invasion. • The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of the bridge tag sign in the diagnosis of visceral pleural invasion were 88.9%, 83.5%, 83.7%, 18.6%, and 99.4%, respectively.

Imaging Assessment of Visceral Pleural Surface Invasion by Lung Cancer: Comparison of CT and Contrast-Enhanced Radial T1-Weighted Gradient Echo 3-Tesla MRI

Objective

To compare the diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3-tesla (3T) magnetic resonance imaging (MRI) and computed tomography (CT) for the detection of visceral pleural surface invasion (VPSI). Visceral pleural invasion by non-small-cell lung cancer (NSCLC) can be classified into two types: PL1 (without VPSI), invasion of the elastic layer of the visceral pleura without reaching the visceral pleural surface, and PL2 (with VPSI), full invasion of the visceral pleura.

Materials and Methods

Thirty-three patients with pathologically confirmed VPSI by NSCLC were retrospectively reviewed. Multidetector CT and contrast-enhanced 3T MRI with a free-breathing radial three-dimensional fat-suppressed volumetric interpolated breath-hold examination (VIBE) pulse sequence were compared in terms of the length of contact, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. Supplemental evaluation of the tumor-pleura interface (smooth versus irregular) could only be performed with MRI (not discernible on CT).

Results

At the tumor-pleura interface, radial VIBE MRI revealed a smooth margin in 20 of 21 patients without VPSI and an irregular margin in 10 of 12 patients with VPSI, yielding an accuracy, sensitivity, specificity, positive predictive value, negative predictive value, and F-score for VPSI detection of 91%, 83%, 95%, 91%, 91%, and 87%, respectively. The McNemar test and receiver operating characteristics curve analysis revealed no significant differences between the diagnostic accuracies of CT and MRI for evaluating the contact length, angle of mass margin, or arch distance-to-maximum tumor diameter ratio as predictors of VPSI.

Conclusion

The diagnostic performance of contrast-enhanced radial T1-weighted gradient-echo 3T MRI and CT were equal in terms of the contact length, angle of mass margin, and arch distance-to-maximum tumor diameter ratio. The advantage of MRI is its clear depiction of the tumor-pleura interface margin, facilitating VPSI detection.

Effects of adjuvant chemotherapy on survival of patients with stage IB non-small cell lung cancer with visceral pleural invasion

BACKGROUND

Adjuvant chemotherapy could improve the prognosis of stage II-III non-small cell lung cancer (NSCLC). However, its influences on stage IB were controversial. The purpose of this study was to investigate whether patients with stage IB NSCLC could benefit from adjuvant chemotherapy.

METHODS

Stage IB NSCLC in 2010-2015 was selected from the surveillance, epidemiology, and end result database. Chi square test was used to compare the clinical characteristics of patients with different adjuvant chemotherapy status. Kaplan-Meier survival curves were plotted by the log-rank test. Cox proportional hazard regression was used to perform multivariate analysis on overall survival (OS), and the life table method was employed to calculate 1-, 3-, and 5-year survival rates.

RESULTS

A total of 2915 patients were included in this study, and the number of patients with visceral pleural invasion (VPI) was 1096 (37.6%), of which 145 (13.2%) received adjuvant chemotherapy. There was no statistical difference in OS among the total population with or without chemotherapy (p = 0.295), nor in patients with VPI (p = 0.216). In patients with VPI, the 1-, 3-, 5-year survival curves of patients who are receiving adjuvant chemotherapy showed an upward trend compared with patients who did not. Additionally, female, high differentiated, adenocarcinoma, and tumor size ≤ 3 cm were also independent prognostic factors for improving the prognosis of patients with VPI.

CONCLUSION

In our study, stage IB NSCLC did not benefit from adjuvant chemotherapy, even in patients with VPI. However, the significance of adjuvant chemotherapy in patients with VPI is still worth further exploration.

EGFR mutations are significantly associated with visceral pleural invasion development in non-small-cell lung cancer patients

OBJECTIVES

A retrospective study was performed to investigate the association between EGFR mutations and visceral pleural invasion (VPI), and evaluate the prognostic value of EGFR in resected non-small-cell lung cancer (NSCLC) patients with VPI.

MATERIALS AND METHODS

Clinicopathological characteristics and follow-up information were collected from 508 consecutive patients with surgically resected stage I-III NSCLC, and EGFR mutations were detected based on real-time PCR technology. Significant results (P<0.05) from univariate logistic regression analysis were involved as covariates to adjust confounding factors in the analysis of independent factors.

RESULTS

VPI and EGFR mutations were detected in 229 (45.1%) and 243 (47.8%) cases in NSCLC, respectively. There was a significant association between EGFR mutations and VPI development. Both 19-del (adjusted OR =2.13, 95%CI =1.13-3.99, P=0.019) and L858R (adjusted OR =2.89, 95%CI =1.59-5.29, P=0.001) could significantly increase the risk of VPI development compared with EGFR wild-type. Higher frequency of L858R (adjusted OR =2.63, 95%CI =1.42-4.88, P=0.002) was detected in VPI patients compared with non-VPI patients. 19-del (adjusted HR =0.31, 95%CI =0.12-0.80, P=0.015) was an independent prognostic factor for a better disease-free survival (DFS) in non-VPI patients. No significant association was shown between EGFR mutations and DFS in VPI patients.

CONCLUSION

EGFR mutations were significantly associated with VPI development in NSCLC, but no significant association was observed between EGFR mutations and DFS in the patients with VPI. 19-del was a favorable prognostic factor for DFS in non-VPI patients.

Score for lung adenocarcinoma in China with EGFR mutation of exon 19: Combination of clinical and radiological characteristics analysis

BACKGROUD

The biopsy samples might be the only tumor material available for testing the EGFR mutation status in some cases, but these samples are often composed of variable ratios of tumor to normal cells. In this study, we sought to build a scoring system to predict Epidermal growth factor receptor (EGFR) exon 19 mutation in lung adenocarcinoma by clinical and radiological features.

METHODS

Enrolled in this study were 601 patients with lung adenocarcinoma. Qualitative evaluation of the clinical and radiological features included 25 aspects. Statistical analysis was used to assess the association of these features between the EGFR wild type and exon 19 mutation, based on a clinical scoring system built by the statistical model and the experience of the radiologists.

RESULTS

EGRF-exon-19-mutation was associated with the female gender [odds ratios (OR), 2.573; 95% confidence intervals (CI), 1.689-3.920], tumor maximum diameter (OR, 0.357; 95% CI, 0.235-0.542), the absence of emphysema (OR, 0.202; 95% CI, 0.110-0.368), the absence of fibrosis (OR, 0.168; 95% CI, 0.083-0.339), and pleural retraction (OR, 2.170; 95% CI, 1.434-3.285). The clinical scoring model assigned 3 points to the female gender, 2 points to small tumor maximum diameter (≤34.5 mm), 2 to the absence of emphysema, 2 to the absence of fibrosis, and 1 to the presence of pleural retraction.

CONCLUSIONS

The scoring system based on the statistical analysis of clinical and radiological features may be a new alternative to the prediction of EGFR mutation subtypes.

CT imaging features associated with recurrence in non-small cell lung cancer patients after stereotactic body radiotherapy

BACKGROUND

Predicting recurrence after stereotactic body radiotherapy (SBRT) in non-small cell lung cancer (NSCLC) patients is problematic, but critical for the decision of following treatment. This study aims to investigate the association of imaging features derived from the first follow-up computed tomography (CT) on lung cancer patient outcomes following SBRT, and identify patients at high risk of recurrence.

METHODS

Fifty nine biopsy-proven non-small cell lung cancer patients were qualified for this study. The first follow-up CTs were performed about 3 months after SBRT (median time: 91 days). Imaging features included 34 manually scored radiological features (semantics) describing the lesion, lung and thorax and 219 quantitative imaging features (radiomics) extracted automatically after delineation of the lesion. Cox proportional hazard models and Harrel's C-index were used to explore predictors of overall survival (OS), recurrence-free survival (RFS), and loco-regional recurrence-free survival (LR-RFS). Five-fold cross validation was performed on the final prognostic model.

RESULTS

The median follow-up time was 42 months. The model for OS contained Eastern Cooperative Oncology Group (ECOG) performance status (HR = 3.13, 95% CI: 1.17-8.41), vascular involvement (HR = 3.21, 95% CI: 1.29-8.03), lymphadenopathy (HR = 3.59, 95% CI: 1.58-8.16) and the 1st principle component of radiomic features (HR = 1.24, 95% CI: 1.02-1.51). The model for RFS contained vascular involvement (HR = 3.06, 95% CI: 1.40-6.70), vessel attachment (HR = 3.46, 95% CI: 1.65-7.25), pleural retraction (HR = 3.24, 95% CI: 1.41-7.42), lymphadenopathy (HR = 6.41, 95% CI: 2.58-15.90) and relative enhancement (HR = 1.40, 95% CI: 1.00-1.96). The model for LR-RFS contained vascular involvement (HR = 4.96, 95% CI: 2.23-11.03), lymphadenopathy (HR = 2.64, 95% CI: 1.19-5.82), circularity (F13, HR = 1.60, 95% CI: 1.10-2.32) and 3D Laws feature (F92, HR = 1.96, 95% CI: 1.35-2.83). Five-fold cross-validated the areas under the receiver operating characteristic curves (AUC) of these three models were all above 0.8.

CONCLUSIONS

Our analysis reveals disease progression could be prognosticated as early as 3 months after SBRT using CT imaging features, and these features would be helpful in clinical decision-making.

Extent of Visceral Pleural Invasion Affects Prognosis of Resected Non-small Cell Lung Cancer: A meta-analysis

Visceral pleural invasion (VPI) has been known to be an adverse prognostic factor in non-small cell lung cancer (NSCLC). However, the prognostic significance of extent of VPI (PL0, PL1 and PL2) remains controversial. We conduct a meta-analysis to summarize available evidence on this topic. PubMed, EMBASE, OVID and The Cochrane Library were searched for published studies from inception to May 9, 2016. A total of 16 studies were included in meta-analysis. Our results showed that patients with PL1 or PL2 had poorer overall survival compared with PL0 (HR = 1.555, 95% CI 1.399, 1.730; HR = 2.447, 95% CI 1.913, 3.130) and patients with PL2 had even poorer overall survival than PL1 (HR = 1.287, 95% CI 1.114, 1.487). Patients with PL1 or PL2 had lower 5-year survival rate than PL0 patients (OR = 0.515, 95% CI 0.415, 0.640; OR = 0.441, 95% CI 0.336, 0.579) and patients with PL2 had even lower 5-year survival rate than PL1 (OR = 0.706, 95% CI 0.545, 0.915). In conclusion, extent of VPI impacts the prognosis of resected NSCLC and VPI should be categorized as PL1 and PL2 in the terms of clinical practice and trials.

Impact of maximum standardized uptake value of non-small cell lung cancer on detecting lymph node involvement in potential stereotactic body radiotherapy candidates

BACKGROUND

The retrospective study investigated the association between the maximum standardized uptake value (SUV_max) of primary tumor and lymph node involvement in potential stereotactic body radiotherapy (SBRT) candidates.

METHODS

A total of 185 patients with clinical stage I NSCLC were enrolled in the current study. All patients underwent lobectomy with systematic lymph node dissection following preoperative FDG-PET/CT scanning. The association between clinicopathological variables and lymph node involvement was analyzed by univariate and multivariate analysis. Spearman's correlation test was used to evaluate the correlation between them. Receiver operating characteristic (ROC) analysis was performed to calculate the area under the curve.

RESULTS

Among these patients, 22.1% had occult lymph node involvement, 15.1% were N1 and 7.0% were N2. Greater tumor size (P=0.007), elevated CEA (P=0.006), central location (P=0.002), higher SUV_max (P<0.001), solid nodule type (P=0.002), visceral pleural invasion (P=0.001) and presence of micropapillary and solid patterns (P=0.002) were significantly associated with lymph node involvement. In multivariate analysis, lymph node involvement was associated with central location (OR 5.784, 95% CI: 1.584-21.114, P=0.008), SUV_max (increase of 1 unite, OR 1.147, 95% CI: 1.035-1.272, P=0.009) and visceral pleural invasion (OR 3.044, 95% CI: 1.369-6.769, P=0.006). ROC area under the curve of SUV_max for lymph node involvement was 0.770 (95% CI: 0.698-0.841), the sensitivity and specificity were 85.4% and 63.2%, respectively. Spearman's correlation test showed that SUV_max of tumor mostly depended on tumor size and nodule type.

CONCLUSIONS

SUV_max of primary tumor was a predictor of lymph node involvement for potential SBRT candidates. Centrally located tumor and visceral pleural invasion were related to higher rate of nodal metastasis. Lobectomy and systemic lymph node dissection should be performed in these patients, instead of SBRT.

The predictive and prognostic values of factors associated with visceral pleural involvement in resected lung adenocarcinomas

Background

The predictive and prognostic impact of factors associated with visceral pleural invasion (VPI) on survival and recurrence in patients with resected lung adenocarcinomas is not clearly defined.

Patients and methods

A total of 505 consecutive patients with stage Ia–IIIa lung adenocarcinomas treated with radical resection were included. The predominant growth pattern was classified according to the new classification system for lung adenocarcinoma proposed by the International Association for the Study of Lung Cancer, the American Thoracic Society, and the European Respiratory Society. The correlations of VPI with clinical and pathologic parameters were analyzed.

Results

The incidence of VPI was significantly lower in lepidic predominant group (15.5% vs 4.5%, P<0.001) and higher in solid and micropapillary predominant group (28.6% vs 17.6%, P=0.004 and 14.7% vs 4.2%, P<0.001, respectively). VPI correlated with higher risk in regional postoperative recurrence (hazard ratio, 2.341; 95% confidence interval, 1.564–3.504) and distant recurrence (hazard ratio, 2.193; 95% confidence interval, 1.665–2.89) in surgically resected lung adenocarcinomas. However, when growth patterns of adenocarcinoma were lumped into multivariate analysis, VPI was not a significant independent predictive factor for survival (P=0.854 for overall survival [OS] and P=0.575 for disease-free survival [DFS]) and recurrence (P=0.38 for regional recurrence and P=0.089 for distant recurrence). Of the 95 patients with stage Ib, those who received adjuvant chemotherapy had longer DFS and OS than the patients who received no chemotherapy after surgery. However, these differences in DFS and OS did not reach statistical significance (P=0.063 for DFS, P=0.85 for OS).

Conclusion

VPI was associated with solid and micropapillary histology. In addition, stage Ib patients with solid histologic subtype tumor showed longer DFS and OS, highlighting a potential benefit in this subgroup of patients and necessitating the need for larger clinical trials.

Association Between Computed Tomographic Features and Kirsten Rat Sarcoma Viral Oncogene Mutations in Patients With Stage I Lung Adenocarcinoma and Their Prognostic Value

BACKGROUND

We investigated the association between computed tomographic (CT) features and Kirsten rat sarcoma viral oncogene (KRAS) mutations in patients with stage I lung adenocarcinoma and their prognostic value.

PATIENTS AND METHODS

A total of 79 patients with pathologic stage I lung adenocarcinoma, available KRAS mutational status, preoperative CT images available, and survival data were included in the present study. Seven CT features, including spiculation, concavity, ground-glass opacity, bubble-like lucency, air bronchogram, pleural retraction, and pleural attachment, were evaluated. The association among the clinical characteristics, CT features, and mutational status was analyzed using Student's t test, the χ(2) test or Fisher's exact test, and logistic regression. The association among CT features, mutational status, and overall survival was analyzed using Kaplan-Meier survival curves with the log-rank test and Cox proportional hazard regression.

RESULTS

The prevalence of KRAS mutations was 41.77%. Spiculation was significantly associated with the presence of KRAS mutations (odds ratio, 2.99; 95% confidence interval [CI], 1.16-7.68). Although KRAS mutational status was not significantly associated with overall survival, the presence of pleural attachment was associated with an increased risk of death (hazard ratio, 2.46; 95% CI, 1.09-5.53). When analyzing KRAS mutational status and pleural attachment combined, patients with wild-type KRAS and no pleural attachment had significantly better survival than did those with wild-type KRAS and pleural attachment (P = .014).

CONCLUSION

These data suggest that spiculation is associated with KRAS mutations and pleural attachment is associated with overall survival in patients with stage I lung adenocarcinoma. Combining the analysis of KRAS mutational status and CT features could better predict survival.

CT Radiogenomic Characterization of EGFR, K-RAS, and ALK Mutations in Non-Small Cell Lung Cancer

OBJECTIVES

To assess the association between CT features and EGFR, ALK, KRAS mutations in non-small cell lung cancer.

METHODS

Patients undergoing chest CT and testing for the above gene mutations were included. Qualitative evaluation of CTs included: lobe; lesion diameter; shape; margins; ground-glass opacity; density; cavitation; air bronchogram; pleural thickening; intratumoral necrosis; nodules in tumour lobe; nodules in non-tumour lobes; pleural retraction; location; calcifications; emphysema; fibrosis; pleural contact; pleural effusion. Statistical analysis was performed to assess association of features with each gene mutation. ROC curves for gene mutations were drawn; the corresponding area under the curve was calculated. P-values <0.05 were considered significant.

RESULTS

Of 285 patients, 60/280 (21.43 %) were positive for EGFR mutation; 31/270 (11.48 %) for ALK rearrangement; 64/240 (26.67 %) for KRAS mutation. EGFR mutation was associated with air bronchogram, pleural retraction, females, non-smokers, small lesion size, and absence of fibrosis. ALK rearrangements were associated with age and pleural effusion. KRAS mutation was associated with round shape, nodules in non-tumour lobes, and smoking.

CONCLUSIONS

This study disclosed associations between CT features and alterations of EGFR (air bronchogram, pleural retraction, small lesion size, absence of fibrosis), ALK (pleural effusion) and KRAS (round lesion shape, nodules in non-tumour lobes).

KEY POINTS

Air bronchogram, pleural retraction, small size relate to EGFR mutation in NSCLC. Pleural effusion and younger age relate to ALK mutation. Round lesion shape, nodules in non-tumour lobes relate to KRAS mutation.

Reevaluation of survival and prognostic factors in pathologic stage I lung adenocarcinoma by the new 2009 TNM classification

The incidence of lung adenocarcinoma has been increased significantly year by year. In this histologic type, complete surgical resection is commonly chosen as treatment method at the initial stages. However, the postoperative survival rate remains unsatisfactory even within the stage I. The purpose of this study is to investigate the factors related with prognosis in stage I lung adenocarcinoma after surgical resection. In this manuscript, a retrospective study was performed. Survival rates were calculated by the Kaplan-Meier method, and for multivariate analyses, Cox proportional hazards regression model was used. The results indicated that a total of 531 patients were included. Overall 5-year survival was 81.2 %. Age, sex, pathologic stage, T category, tumor size, differentiation, necrosis, visceral pleural invasion (VPI), lymphatic vessel or vascular invasion, and serum carcinoembryonic antigen (CEA) were significantly associated with 5-year overall survival of the patients with Kaplan-Meier analysis. Moreover, on multivariate analyses, seven variables were shown to be independent prognostic factors, including differentiation (hazard ratios (HR), 1.357), VPI (HR, 0.551), lymphatic vessel or vascular invasion (HR, 0.533), necrosis (HR, 1.671), age (HR, 1.519), pathological stage (HR, 4.477), and CEA (HR, 2.099). In conclusion, the most important prognostic factor is pathologic stage. Other adverse prognostic factors include differentiation, VPI, lymphatic vessel or vascular invasion, necrosis, age, and CEA.

Visceral pleural invasion is not predictive of survival in patients with lung cancer and smaller tumor size

BACKGROUND

Visceral pleural invasion (VPI) is used as an indicator of adverse prognosis in non-small cell lung cancer (NSCLC). The purpose of this retrospective study was to evaluate the impact of VPI on disease-free survival (DFS) and overall survival (OS) in patients with node-negative NSCLC.

METHODS

Between 1998 and 2009, 1,166 patients with pathologic N0M0 NSCLC underwent surgical resection by lobectomy. Two hundred fourteen patients with VPI were compared with 952 patients without VPI.

RESULTS

Median follow-up was 59 months. In multivariate analysis, VPI, larger tumor size, older age, female sex, and poor performance status were significantly associated with decreased OS. In contrast, larger tumor size, female sex, and poor performance, but notably not VPI, were associated with decreased DFS. After examining interactive effects of VPI and T stage subgroups, we found that VPI did not significantly affect either OS or DFS in the subgroups of patients with smaller tumor sizes-stage T1a, stage T1b, or stage T2a. In contrast, a deleterious effect of VPI on DFS was seen for tumors larger than 5 cm-stages T2b and T3-with the VPI-stage T3 interaction effect being statistically significant for DFS but not for OS.

CONCLUSIONS

The effect of VPI on survival in NSCLC varies greatly with tumor size, with VPI not strongly associated with OS or DFS in tumors smaller than 5 cm, but showing large negative effects on DFS for stage T2b and stage T3 tumors. Using VPI to upstage T1 tumors to a higher T stage is not warranted because it would misrepresent these VPI-T stage subgroup effects.