Prognostic Significance of a Solid Component in Pulmonary Adenocarcinoma

The role of adenocarcinoma subtypes and immunohistochemistry in predicting lymph node metastasis in early invasive lung adenocarcinoma

BACKGROUND

Identifying lymph node metastasis areas during surgery for early invasive lung adenocarcinoma remains challenging. The aim of this study was to develop a nomogram mathematical model before the end of surgery for predicting lymph node metastasis in patients with early invasive lung adenocarcinoma.

METHODS

In this study, we included patients with invasive lung adenocarcinoma measuring ≤ 2 cm who underwent pulmonary resection with definite pathology at Qilu Hospital of Shandong University from January 2020 to January 2022. Preoperative biomarker results, clinical features, and computed tomography characteristics were collected. The enrolled patients were randomized into a training cohort and a validation cohort in a 7:3 ratio. The training cohort was used to construct the predictive model, while the validation cohort was used to test the model independently. Univariate and multivariate logistic regression analyses were performed to identify independent risk factors. The prediction model and nomogram were established based on the independent risk factors. Recipient operating characteristic (ROC) curves were used to assess the discrimination ability of the model. Calibration capability was assessed using the Hosmer-Lemeshow test and calibration curves. The clinical utility of the nomogram was assessed using decision curve analysis (DCA).

RESULTS

The overall incidence of lymph node metastasis was 13.23% (61/461). Six indicators were finally determined to be independently associated with lymph node metastasis. These six indicators were: age (P < 0.001), serum amyloid (SA) (P = 0.008); carcinoma antigen 125 (CA125) (P = 0. 042); mucus composition (P = 0.003); novel aspartic proteinase of the pepsin family A (Napsin A) (P = 0.007); and cytokeratin 5/6 (CK5/6) (P = 0.042). The area under the ROC curve (AUC) was 0.843 (95% CI: 0.779-0.908) in the training cohort and 0.838 (95% CI: 0.748-0.927) in the validation cohort. the P-value of the Hosmer-Lemeshow test was 0.0613 in the training cohort and 0.8628 in the validation cohort. the bias of the training cohort corrected C-index was 0.8444 and the bias-corrected C-index for the validation cohort was 0.8375. demonstrating that the prediction model has good discriminative power and good calibration.

CONCLUSIONS

The column line graphs created showed excellent discrimination and calibration to predict lymph node status in patients with ≤ 2 cm invasive lung adenocarcinoma. In addition, the predictive model has predictive potential before the end of surgery and can inform clinical decision making.

Contemporary Incidence of Synchronous Multiple Primary Lung Cancers and Survival in the Era of Lung Cancer Screening

OBJECTIVE

Up to 15% of lung cancer patients have multiple suspicious nodules. While some of these nodules may represent metastatic lung cancer, others represent synchronous multiple primary lung cancer (SMPLC). The incidence of SMPLC ranges from 0.8% to 8.4% and appears to be increasing. Inconsistent identification of SMPLC can be detrimental for patients who are misdiagnosed as having intrapulmonary metastasis and not offered stage-based treatment. We sought to identify the contemporary incidence of SMPLC at a tertiary institution.

METHODS

From January 2018 to September 2019, patients who underwent lung cancer resection were retrospectively reviewed. Patients with SMPLC were identified using the modified Martini-Melamed criteria.

RESULTS

During the 21-month period, 227 patients underwent lung cancer resection. There were 47 patients (20.7%) who had 119 pathologically confirmed SMPLC. Most patients had ipsilateral tumors (n = 24, 51.1%) with at least 1 adenocarcinoma (n = 40, 85.1%). Considering histologic subtyping, 38 (80.9%) had histologically distinct tumors. Overall and cancer-specific survival at 4 years was 86% and 90%, respectively. Only patients with 3 or more SMPLC had poor 4-year overall (P = 0.002) and cancer-specific survival (P = 0.043) compared with those with 2 SMPLC. Patient demographics, histology, tumor location, and highest pathologic staging did not affect survival outcomes.

CONCLUSIONS

Using a strict inclusion criterion, the incidence of SMPLC is higher than previously reported. SMPLC patients have favorable survival outcomes, suggesting that they behave like primary lung cancer, not intrapulmonary metastasis. Awareness of SMPLC by thoracic surgeons is critical in optimizing outcomes in this patient population.

Morphological and genetic heterogeneity of synchronous multifocal lung adenocarcinoma in a Chinese cohort

Background

Synchronous multifocal lung cancer (SMLC) is diagnosed with increasing frequency in clinical practice globally. Due to innate variation in clinical management and outcome, it is vital to properly distinguish between synchronous multifocal primary lung cancer (SMPLC) and intrapulmonary metastasis (IM). The pathologic features and principal classification criteria of multifocal lung cancer remain unclear. Our objective was to evaluate the diagnostic value of histological morphologic features and driver gene mutations in SMLC classification.

Methods

We collected a unique cohort of Chinese patients with SMLC, and fully explored the morphologic, immunohistochemical, and molecular features of the disease. Twenty-one SMLC patients with a total of 50 tumours were included in our study. The pathological features that were presented by these patients were analysed, including the tumours location, tumours size, pathological types, predominant pattern of adenocarcinoma, and immunohistochemical staining. We conducted molecular testing of nine driver oncogenes that are associated with lung cancer, namely, EGER, KRAS, BRAF, NRAS, ALK, ROS1, RET, HER2, and PIK3CA.

Results

According to the Martini-Melamed classification and refined standard, 8 and 17 patients, respectively, were considered to have SMPLCs. Gene mutations were identified in 18 tumours (36%). Twelve patients had different gene mutations.

Conclusions

We demonstrate that conventional morphological assessment is not sufficient to clearly establish the clonal relationship of SMPLCs. Instead, the evaluation of histological subtypes, including nonmucinous adherent components, is required. Multiplex genotypic analysis may also prove to be a useful additional tool.

Prognostic Significance of Ground-Glass Opacity Components in 5-Year Survivors With Resected Lung Adenocarcinoma

BACKGROUND

Reports on the prognosis for 5-year survivors with lung adenocarcinoma after resection are sparse. This study aimed to identify factors associated with overall survival (OS) and cancer-specific survival (CSS) for 5-year survivors with completely resected lung adenocarcinoma, and to determine whether preoperative imaging factors, including the presence of ground-glass opacity (GGO) components, affect late recurrence in long-term survivors.

METHODS

Complete resection of lung adenocarcinoma was performed for 1681 patients between January 2000 and December 2013. Of these patients, 936 who survived 5 years or longer after surgery were identified, and factors associated with OS and CSS were determined using the Cox proportional hazard model.

RESULTS

Multivariable analysis demonstrated that lymph node metastasis (p < 0.01) and absence of GGO components (p < 0.01) were independently associated with OS and CSS for the 5-year survivors. The absence of GGO components was significantly associated with OS (p < 0.01) and CSS (p < 0.01) also for the 5-year survivors with stage 1 disease (n = 782) and for the 5-year survivors without recurrence (n = 809). The incidence of recurrence anytime during the 10-year postoperative follow-up period differed significantly between the 5-year survivors with and without GGO components.

CONCLUSIONS

The absence of GGO components was significantly associated with an unfavorable prognosis for the 5-year survivors with completely resected lung adenocarcinoma regardless whether they had recurrences not.

Prognostic Effects of Predominant Histologic Subtypes in Resected Pulmonary Adenocarcinomas

Background

Predominant histologic subtypes have been reported as predictors of survival of patients with pulmonary adenocarcinoma.

Aims

To evaluate the predictive value of histologic classification in resected lung adenocarcinoma using the classification systems proposed by the International Association for the Study of Lung Cancer, American Thoracic Society, European Respiratory Society, and World Health Organization (2015).

Study Design

Cross-sectional study.

Methods

The histologic classification of a large cohort of 491 patients with resected lung adenocarcinoma (stages I-III) was retrospectively analyzed. The tumors were classified according to their predominant component (lepidic, acinar, papillary, solid, micropapillary, and mucinous), and their predictive values were assessed for clinicopathologic characteristics and overall survival.

Results

The patient cohort comprised 158 (32.2%) patients with solid predominant, 150 (30.5%) with acinar predominant, 80 (16.3%) with papillary predominant, 75 (15.3%) with lepidic predominant, 22 (4.5%) with mucinous, and 5 (1.0%) with micropapillary subtype, and 1 (0.2%) with adenocarcinoma in situ. Overall 5-year survival of 491 patients was found to be 51.8%. Patients with lepidic, acinar, and mucinous adenocarcinoma had 70.9%, 59.0%, and 66.6% 5-year survival, respectively, and there was no statistically significant difference between them. Whereas patients with solid, papillary, and micropapillary predominant adenocarcinoma had 41.0%, 40.5%, and 0.0% 5-year survival, respectively. Compared to other histologic subtypes, patients with solid and papillary predominant adenocarcinoma had significantly lower survival than those with lepidic (p<0.001, p=0.002), acinar (p<0.001, p=0.008), and mucinous (p=0.048, p=0.048) subtypes, respectively. The survival difference between patients with solid subtype and those with papillary subtype was not statistically significant (p=0.67).

Conclusion

Solid and papillary histologic subtypes are poor prognostic factors in resected invasive lung adenocarcinoma.

Radiomic signature: a non-invasive biomarker for discriminating invasive and non-invasive cases of lung adenocarcinoma

Purpose

We aimed to assess the classification performance of a computed tomography (CT)-based radiomic signature for discriminating invasive and non-invasive lung adenocarcinoma.

Patients and Methods

A total of 192 patients (training cohort, n=116; validation cohort, n=76) with pathologically confirmed lung adenocarcinoma were retrospectively enrolled in the present study. Radiomic features were extracted from preoperative unenhanced chest CT images to build a radiomic signature. Predictive performance of the radiomic signature were evaluated using an intra-cross validation cohort. Diagnostic performance of the radiomic signature was assessed via receiver operating characteristic (ROC) analysis.

Results

The radiomic signature consisted of 14 selected features and demonstrated good discrimination performance between invasive and non-invasive adenocarcinoma. The area under the ROC curve (AUC) for the training cohort was 0.83 (sensitivity, 0.84 ; specificity, 0.78; accuracy, 0.82), while that for the validation cohort was 0.77 (sensitivity, 0.94; specificity, 0.52 ; accuracy, 0.82).

Conclusion

The CT-based radiomic signature exhibited good classification performance for discriminating invasive and non-invasive lung adenocarcinoma, and may represent a valuable biomarker for determining therapeutic strategies in this patient population.

Papillary predominant histological subtype predicts poor survival in lung adenocarcinoma

BACKGROUND

This study aims to investigate whether papillary predominant histological subtype can predict poor survival in lung adenocarcinoma.

METHODS

Between January 2005 and December 2016, a total of 80 patients with papillary predominant subtype lung adenocarcinoma (70 males, 10 females; mean age 60.7 years; range, 42 to 79 years) operated in our clinic were included in the study. These patients were compared with those having lepidic, acinar, and mucinous subtypes. Overall and five-year survival rates were evaluated.

RESULTS

Five-year survival was 40.5% in papillary predominant histological subtype, while this rate was 70.9%, 59.0%, and 66.6% in lepidic, acinar, and mucinous subtypes, respectively. Papillary subtype showed significantly poor survival compared to lepidic (p=0.002), acinar (p=0.008), and mucinous subtypes (p=0.048). In Stage 1 disease, it was more evident (papillary, 47.5%, lepidic 86.9% [p=0.001], acinar 69.3% [p=0.040], and mucinous 90.0% [p=0.050]).

CONCLUSION

Our study results suggest that papillary predominant subtype predicts poor survival in lung adenocarcinoma and these cases may be candidates for adjuvant treatment modalities even in the earlier stages of disease.

Solid predominant subtype in lung adenocarcinoma is related to poor prognosis after surgical resection: A systematic review and meta-analysis

BACKGROUND

Recent studies have indicated that solid predominant (SP) subtype of lung adenocarcinoma (LADC) may be associated with early recurrence and worse prognosis. Hence, a systematic review and meta-analysis were performed to evaluate the association between LADC subtype and survival.

METHODS

The MEDLINE, SCOPUS, Web of Science and Cochrane Libraries were reviewed for eligible studies in December 2017. Studies were included if they compared outcomes of patients with and without SP subtype in resection specimens of LADC patients after surgical treatment by using multivariate Cox regression analysis. A meta-analysis for overall survival (OS) and disease-free survival (DFS) was performed. The hazard ratios (HR) or odds ratios with 95% confidence intervals (CIs) from each study were used to calculate pooled HRs. Statistical analyses were performed using Review Manager 5.3.

RESULTS

In total, 14 eligible studies including 12,137 LADC patients were identified, which assessed the impact of SP subtype on OS and DFS in patients treated with pulmonary resection. SP subtype was reported in 1246 (10.2%) patients and was associated with significantly worse OS (pooled HR, 1.51; 1.29-1.75) and DFS (pooled HR, 1.26; 1.14-1.40).

CONCLUSIONS

SP subtype is associated with significantly worse OS and DFS in patients with LADC after pulmonary resection. These data provide evidence for the integration of the distinct histological LADC subtyping into prognostic tools and guidelines for adjuvant treatment after complete surgical resection.

Lymph node involvement according to lung adenocarcinoma subtypes: lymph node involvement is influenced by lung adenocarcinoma subtypes

Backgrounds

Invasive adenocarcinoma subtypes are known to be associated with prognosis; however, the underlying reason remains unclear. To find out the reason, we investigated the possible influence of lymph node (LN) involvement by the constituent histologic subtypes in the tumor and clarified the different prognosis according to the predominant histologic subtypes in the tumor and LN.

Methods

A total of 97 consecutive patients who underwent surgical resection for lung invasive adenocarcinoma between February 2009 and December 2015 were included. We analyzed the associations of the histologic subtypes between the tumor and LN and disease-free survival (DFS) according to the histologic subtypes and predicted the histologic subtype in LN involvement using the component ratio of the predominant histologic subtype in the tumor. A P value <0.05 was considered statistically significant.

Results

Acinar and papillary subtypes occupied the majority of the predominant histological subtypes (tumor 73.2%, LN 71.1%). The tumor showed significantly more constituent histologic subtypes than LN (P<0.001). Micropapillary and solid predominant subtype were more common in poorer differentiation (tumor P<0.001, LN P=0.001). The predominant histologic subtype in the tumor was not the same as that in LN and micropapillary and solid predominant subtypes were significantly more prone to LN involvement than other subtypes (P<0.001). Regarding the predominant histologic subtypes in the tumor, there was no significant difference in DFS between micropapillary and solid predominant subtypes and other subtypes. However, regarding the predominant histologic subtypes in LN, micropapillary and solid predominant subtypes had significantly lower DFS than other subtypes (P=0.010). Solid predominant subtype had a significant cutoff value for prediction of the predominant histologic subtype in LN using the component ratio of the predominant histologic subtype in the tumor (cutoff value 12.5%, sensitivity 70.0%, specificity 82.4%, area 0.775, P<0.001).

Conclusions

The present study presented a possible reason of discrepancies in outcomes according to the lung adenocarcinoma constituent subtypes. Micropapillary and solid predominant subtypes had poorer prognosis than other subtypes, which might be explained by being more prone to LN involvement.

Histopathologic and molecular approach to staging of multiple lung nodules

Distinguishing multiple primary lung cancers from intrapulmonary metastases in patients with synchronous multifocal lung adenocarcinomas can be challenging. The most recent 8th edition American Joint Committee on Cancer staging manual (AJCC staging manual) distinguishes four disease patterns in patients with multiple lung nodules: (I) two or more distinct and histologically different masses (considered unrelated and staged as individual cancers); (II) multiple ground-glass or part-solid nodules, histologically of with lepidic growth pattern (considered separate tumors, T staged based on highest T stage lesion); (III) patchy areas of ground-glass and consolidations, histologically often invasive mucinous adenocarcinomas (considered single tumor with diffuse "pneumonic-type" involvement); and (IV) separate nodules with the same histologic features based on comprehensive histologic subtyping (considered intrapulmonary metastases). Histologic and molecular features, in conjunction with clinical and radiological information, can all be tools to assist with staging of multiple nodules. Histologic features of adenocarcinomas are best characterized using comprehensive histologic subtyping (percentage of lepidic, acinar, solid, papillary and micropapillary pattern). Genomic alterations are commonly assessed using fluorescence in-situ hybridization and next generation sequencing (NGS). The AJCC considers exactly matching breakpoints by comparative genomic hybridization (CGH) as the only evidence for intrapulmonary metastases, and clearly different histologic types or subtypes as the only evidence for separate primary tumors. Similar histologic subtypes or the same biomarker pattern are considered merely relative arguments in favor of a single tumor source. When assessing multifocal lung cancer, pathologists should consider, and carefully weigh the importance of, molecular testing results in addition to the tumor's histologic features. For many cases encountered in routine clinical practice, absolute certainty cannot be reached as to whether they represent multiple primary cancers or intrapulmonary metastases. Classification of difficult cases often benefits from multidisciplinary discussion.

MicroRNA Expression Profile on Solid Subtype of Invasive Lung Adenocarcinoma Reveals a Panel of Four miRNAs to Be Associated with Poor Prognosis in Chinese Patients

According to the reclassification of lung adenocarcinoma (LAC) proposed in 2011, solid predominant lung adenocarcinoma (SPA) has been associated with poor outcomes for LAC patients. However, the prognostic value of the presence of solid subtype remains unclear. Besides, there is little data about the roles of microRNA (miRNA) in solid subtype of LAC. In this study, 243 LAC patients were classified into solid subtype positive and negative groups (S+ LAC, n=134 and S- LAC, n=109) according to whether the solid subtype was more than 5% of the tumor component or not. We analyzed the relationship between solid subtype and patients' outcome by univariate and multivariate analyses. Solid subtype was proved to be significantly associated with the 5-year overall survival and played as an independent prognostic factor for stage I-III invasive LAC patients. Then miRNA microarray was used to identify differentially expressed miRNAs in solid subtype, resulting in 31 differential miRNAs. Quantitative reverse transcription-PCR (QRT-PCR) was used to validate 4 key miRNAs (miR-133b, miR-155-5p, miR-124-3p, miR-145-5p). Further, CCK-8 and transwell assays were performed to validate the impact of one dysregulated miRNA (miR-133b) on LAC cell function. Interestingly, while miR-133b could significantly inhibit the proliferation of A549 and SPC-A1, it showed no effect on the migration or invasion of LAC cell lines. These results suggest that solid subtype can exert independent prognostic impact on LAC patients, and 4 important dysregulated miRNAs in solid subtype of LAC may be involved in the malignancy of S+LAC, thus may further have clinical perspective for S+ LAC in the future.

[Clinical and paraclinical prognostic factors in non-small cell lung cancer surgery]

INTRODUCTION

Lung cancer prognosis is mainly based on the TNM, histology and molecular biology. Our aim was to analyze the prognostic value of certain clinical and paraclinical variables.

PATIENTS AND METHODS

We studied among 6105 patients operated on, divided during 3 time-periods (1979 to 2010), the following prognostic factors: type of surgery, pTNM, histology, age, sex, smoking history, clinical presentation, and paraclinical variables.

RESULTS

Postoperative mortality was 4% (243/6105), rate of complications was 23.3% (1424/6105). The 5-year overall survival was 43.2% and 10-year was 27%. Best survival was observed after complete resection (R0) (P<10(-6)), lobectomy (P<10(-6)), lymph node dissection (P=0.0006), early pTNM stages (P<10(-6)), absence of a solid component in adenocarcinoma. Other pejorative factors were: male gender (P=10(-5)), age (P=0.0000002), comorbidity (P=0.016), history of cancer (P<10(-5)), postoperative complications (P=0.0018), FEV lower than 80% (P=0.0000025), time-periods (P<10(-6)). All these factors were confirmed by multivariate analysis, except gender. Smoking was not poor prognostic factor in univariate analysis (P=0.09) but became significant in the multivariate one (P=0.013).

CONCLUSION

Medical and human factors, and the general physiological state, play an important role in prognosis after surgery. We do not know their exact meaning and, like studies on chemotherapy, they justify special research.

International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification predicts occult lymph node metastasis in clinically mediastinal node-negative lung adenocarcinoma

OBJECTIVES

We investigated the role of the 2011 International Association for the Study of Lung Cancer, American Thoracic Society, and European Respiratory Society (IASLC/ATS/ERS) classification in predicting occult lymph node metastasis in clinically mediastinal node-negative lung adenocarcinoma.

METHODS

We reviewed lung adenocarcinoma patients who had clinically N2-negative status, were evaluated by preoperative positron emission tomography combined with computed tomography (PET/CT) and had undergone lobectomy or pneumonectomy at Memorial Sloan Kettering Cancer Center (n = 297). Tumours were classified according to the 2011 IASLC/ATS/ERS classification. The associations between occult lymph node metastasis and clinicopathological variables were analysed using Fisher's exact test and logistic regression analysis.

RESULTS

Thirty-two (11%) cN0-1 patients had occult mediastinal lymph node metastasis (pN2) whereas 25% of cN1 patients had pN2 disease. Increased micropapillary pattern was associated with increased risk of pN2 disease (P = 0.001). On univariate analysis, high maximum standard uptake value of the primary tumour on PET/CT (P = 0.019) and the presence of micropapillary (P = 0.014) and solid pattern (P = 0.014) were associated with occult pN2 disease. On multivariable analysis, micropapillary pattern was positively associated with risk of pN2 disease (odds ratio = 3.41; 95% confidence intervals = 1.42-8.19; P = 0.006).

CONCLUSIONS

The presence of micropapillary pattern is an independent predictor of occult mediastinal lymph node metastasis. Our observations have potential therapeutic implications for management of early-stage lung adenocarcinoma.

Accuracy of the IASLC/ATS/ERS histological subtyping of stage I lung adenocarcinoma on intraoperative frozen sections

Histological subtyping of surgically resected lung adenocarcinoma has been shown to be of prognostic significance, and limited surgical resection has been proposed as a treatment of choice for early-stage lung adenocarcinoma. The accuracy of histological subtyping has been recently assessed in the surgical resection and small biopsy specimens; however, the accuracy of intraoperative subtyping on frozen sections remains relatively unknown. The aim of this study was to determine diagnostic accuracy and interobserver variability in histological subtyping of lung adenocarcinoma on intraoperative frozen sections. Overall, 112 consecutive cases of surgically resected stage I lung adenocarcinoma were reviewed independently by three pathologists. Histological patterns (acinar, lepidic, papillary, micropapillary, and solid) and mucinous variant were recorded in 5% increments for each intraoperative frozen and permanent sections. Primary and secondary histological patterns were assigned in each case. Kappa scores were calculated to evaluate agreement between pathologists in the assessment of histological subtype on intraoperative frozen sections versus permanent sections. Overall agreement between intraoperative frozen and permanent sections was moderate for primary pattern (69.7% of cases), with kappa scores ranging from 0.43 to 0.58, with more consistent agreement for stage IA tumors. Kappa scores for the secondary pattern ranged from 0.16 to 0.32. Acinar and solid patterns were most likely to be correctly identified as primary growth patterns. Micropapillary pattern was recognized in only 11-55% of cases. The main reasons for discrepancies between intraoperative frozen and permanent sections were inadequate sampling and poor quality of frozen sections. Our study suggests that it is difficult to predict the primary adenocarcinoma pattern on a single representative frozen section. This observation suggests a potential impact on the extent of frozen section sampling by pathologists at the time of intraoperative consultation, if surgical management of stage I lung adenocarcinoma will be guided by its histological subtype.

Using frozen section to identify histological patterns in stage I lung adenocarcinoma of ≤ 3 cm: accuracy and interobserver agreement

AIMS

The IASLC/ATS/ERS classification of lung adenocarcinoma provides a prognostically significant histological subclassification. The aim of this study was to investigate the accuracy, limitations and interobserver agreement of frozen sections for predicting histological subtype.

METHODS AND RESULTS

Frozen section and permanent section slides from 361 resected stage I lung adenocarcinomas ≤ 3 cm in size were reviewed for predominant histological subtype and the presence or absence of lepidic, acinar, papillary, micropapillary and solid patterns. Fifty cases were additionally reviewed by three pathologists to determine interobserver agreement. To test the accuracy of frozen section in judging degree of invasion, five pathologists reviewed frozen section slides from 35 cases with a predominantly lepidic pattern. There was moderate agreement on predominant histological subtype between frozen sections and final diagnosis (κ = 0.565). Frozen sections had high specificity for micropapillary and solid patterns (94% and 96%, respectively), but sensitivity was low (37% and 69%, respectively). The interobserver agreement was satisfactory (κ > 0.6, except for the acinar pattern).

CONCLUSIONS

Frozen section can provide information on the presence of aggressive histological patterns-micropapillary and solid-with high specificity but low sensitivity. It was difficult to predict the predominant pattern on the basis of frozen sections, mostly because of sampling issues.

Clinical and pathologic prognostic factors that are influential in the survival and prognosis of lung adenocarcinomas and invasive predominant subtypes

Therapeutic approaches to lung adenocarcinomas differ because of their heterogeneous morphologies, prognoses, and clinical features. For this reason, new histopathologic classifications for lung adenocarcinomas were done by the International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society to form subtypes with homogeneous prognoses. There are limited clinical data in the literature on the prognosis of the subgroups formed according to the new classification. A total of 86 patients with adenocarcinoma who had undergone pathologic stages I and II curative resection and mediastinal lymph node dissection were retrospectively analyzed according to the seventh TNM staging system revised by the Union for International Cancer Control/American Joint Committee on Cancer. Histologic subtyping was reassessed according to the dominant histopathologic morphology. When survival rates of lung adenocarcinomas were compared according to their localizations, it was observed that adenocarcinomas localized to the right hemithorax had a longer survival than the ones with left hemithorax localization (P = 0.026). When necrosis was taken into account, it was seen that necrosis rate was higher in solid predominant type compared with other types, whereas it was lower in acinary type (P = 0.046). When peritumoral lymphovascular invasion data were assessed, it was observed that disease-free survival was influenced in a negative fashion (P = 0.018). New histopathologic classification of adenocarcinomas has been a step forward to attaining homogeneous groups, but when the biologic heterogeneity of the adenocarcinomas is taken into account, the authors believe that considering the peritumoral lymphatic vascular invasion, left hemithorax localization, and tumoral necrosis entities in the upcoming TNM classification will contribute to evaluating the prognosis.

Lung cancer staging: clinical and radiologic perspectives

Published in 2009, the 7th edition of the American Joint Committee on Cancer TNM staging system is the culmination of an extensive worldwide initiative to standardize and validate lung cancer staging. Unlike prior editions, the new staging system is now inclusive of small cell carcinoma and carcinoid tumors. In addition, significant changes were made to the T and M descriptors, resulting in improved prognostic stratification of disease. This review article highlights these changes, the rationale for their inclusion in the new staging manual, and the role of the radiologist in determining stage.

Alteration of the E-Cadherin/β-Catenin Complex Is an Independent Poor Prognostic Factor in Lung Adenocarcinoma

Background

Epithelial-mesenchymal transition (EMT) is an important step in the invasion and progression of cancer and in the development of chemoresistance by cancer cells.

Methods

To address the clinical significance of the EMT pathway in lung adenocarcinoma and the association of the pathway with histological subtype, we examined 193 surgically resected lung adenocarcinoma samples for the expression of representative EMT-related proteins (E-cadherin, β-catenin, and vimentin) by immunohistochemistry. Histological subtypes were classified according to the 2011 International Association for the Study of Lung Cancer/American Thoracic Society/European Respiratory Society classification. The results for EMT-related protein expression were analyzed for correlation with clinicopathological features and with survival.

Results

The loss of E-cadherin expression and aberrant β-catenin expression were significantly associated with larger tumor size, pleural invasion, lymphatic/vascular invasion, and advanced pathological stage (p<0.05). The alteration of the E-cadherin/β-catenin complex was least frequently observed in the lepidic-predominant group, but these associations were not statistically significant. In the multivariate analysis, altered E-cadherin/β-catenin complex expression was found to be an independent poor prognostic factor (p=0.017; hazard ratio, 1.926; 95% confidence interval, 1.119 to 3.314).

Conclusions

The alteration of the expression of the E-cadherin/β-catenin complex was associated with aggressive tumor behavior in lung adenocarcinoma.

Forkhead box P3 regulatory T cells coexisting with cancer associated fibroblasts are correlated with a poor outcome in lung adenocarcinoma

Recently, an association between tumor infiltrating Forkhead box P3 regulatory T cells (Treg ) and an unfavorable prognosis has been clinically shown in some cancers, but the mechanism of Treg induction in the tumor microenvironment remains uncertain. The aims of the present study were to examine the relationship between Treg and patient outcome and to investigate whether Treg induction is influenced by the characteristics of cancer-associated fibroblasts (CAF) in lung adenocarcinoma. The numbers of Treg in both the tumor stroma and the tumor nest were counted in 200 consecutive pathological stage I lung invasive adenocarcinoma specimens. To examine whether the characteristics of CAF influence Treg induction, we selected and cultured CAF from low Treg and high Treg adenocarcinoma. The number of Treg was much higher in the stroma than in the nest (P < 0.01). Patients with high Treg had a significantly poorer prognosis than those with low Treg (overall survival: P = 0.03; recurrence-free survival: P = 0.02; 5-year overall survival: 85.4% vs 93.0%). Compared with the CAF from low Treg adenocarcinoma, culture supernatant of the CAF from high Treg adenocarcinoma induced more Treg (P = 0.01). Also, CAF from high Treg adenocarcinoma expressed significantly higher mRNA levels of transforming growth factor-β (P = 0.01) and vascular endothelial growth factor (P = 0.01), both of which are involved in Treg induction. Our studies suggest the possibility that CAF expressing immunoregulatory cytokines may induce Treg in the stroma, creating a tumor-promoting microenvironment in lung adenocarcinoma that leads to a poor outcome.

Characteristic immunophenotype of solid subtype component in lung adenocarcinoma

BACKGROUND

Lung adenocarcinomas represent a morphologically heterogeneous tumor composed of an admixture of different histologic subtypes (lepidic, papillary, acinar, and solid subtype). The presence of a solid subtype component is reported to be associated with a poorer prognosis. The aim of this study was to evaluate the characteristic immunophenotype of the solid subtype component compared with the immunophenotypes of other components.

METHODS

We analyzed the clinicopathological characteristics of stage I adenocarcinoma patients with predominant solid subtype disease. Furthermore, we immunostained adenocarcinomas with predominant lepidic, papillary, acinar, and solid subtype components (n = 23 each) for 10 molecular markers of tumor invasiveness and scored the results.

RESULTS

Patients showing predominance of the solid subtype component (solid subtype adenocarcinoma) had a poorer prognosis than those showing predominance of the lepidic, papillary, or acinar component. Lymphovascular invasion was more often detected in solid subtype tumors than in others. The solid subtype component showed a significantly stronger staining intensity of laminin-5 expression than the lepidic, papillary, and acinar components (P < 0.001, P < 0.001, and P = 0.016, respectively). The fibronectin and vimentin expression levels were also significantly higher in the solid subtype component than in other components. This immunostaining character was validated by using mixed-subtype adenocarcinomas containing all four components in the same tumor.

CONCLUSIONS

This study concluded that the solid subtype component in lung adenocarcinomas exhibit the invasive immunophenotype, including increased laminin-5 expression, compared with the other components, which may be associated with a poorer prognosis.