Differences in clinicopathological and biological features between central-type and peripheral-type squamous cell carcinoma of the lung

Long-term results of middle lobectomy patients operated for non-small cell lung cancer

Objectives

Lobectomy is the most frequently performed surgical treatment for lung cancer; isolated middle lobectomy (IML) is the least frequently performed lobectomy. Until recently, IML performed for Non-Small Cell Lung Cancer (NSCLC) located in the middle lobe of the lung was considered insufficient in oncologic surgery, and upper bilobectomy (Upper lobe + Middle lobe) or lower bilobectomy (Lower lobe + Middle lobe) was performed for isolated middle lobe tumors. Since postoperative morbidity and mortality rates are worse in bilobectomy compared to lobectomy, IMLs have become frequently performed. In this study, patients who underwent IML for NSCLC were compared with upper or lower lobectomies (ULL), and the oncologic results of patients who underwent IML were evaluated.

Materials and methods

In this study, 45 patients who underwent IML at our institution between 2012 and 2022 and 45 patients, who underwent right upper or lower lobectomy and were similar in terms of gender and age, were retrospectively analyzed. Oncological outcomes between these two groups were evaluated.

Results

The mean age of 45 patients, 34 (75.6%) male and 11 (24.5%) female, who underwent IML was found to be 62.5 ± 8.4 years. According to the type of surgery, 27 (60%) patients underwent thoracotomy and 18 (40%) patients underwent Video-Assisted Thoracoscopic Surgery (VATS). When tumor histopathologies were examined in all lobectomy patients, it was seen that squamous cell carcinoma was statistically significantly more dominant in IML patients than in the other two lobectomy groups (p = 0.014). In addition, it was seen that the tumor size was smaller in IML patients than in the other groups (p = 0.005). When the survival characteristics between these two groups were evaluated, the overall survival time (OS) of patients who underwent IML was 118.0 (59.0-124.0) months, while the overall survival time of patients who underwent ULL was 71.0 (66.0-74.0) months, and no statistically significant difference was found between the groups. No statistically significant difference was observed between the groups in terms of 30-day and 90-day mortality rates and 5-year survival rates.

Conclusion

There was no significant difference in survival between patients who underwent IML for NSCLC and those who underwent same-sided ULL. Based on these results, IML can be considered as an oncologically appropriate treatment option for masses confined to the middle lobe without the need for bilobectomy.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-024-01886-4.

The Impact of Ultracentral Tumor Location on Outcomes in Patients with Pulmonary Oligometastases: A Secondary Analysis of the Single-Arm Phase 2 SABR-5 Trial

PURPOSE/OBJECTIVES

There are limited data on outcomes in patients with ultracentral pulmonary oligometastases treated with SABR. The purpose of this study was to determine whether ultracentral location was prognostic for toxicity and survival.

MATERIAL AND METHODS

Oligometastatic lung lesions treated on the single-arm phase 2 SABR-5 trial were retrospectively stratified into 2 cohorts: ultracentral tumors (UC), defined as planning target volume overlap or direct tumor abutment to the proximal bronchial tree, esophagus, great vessels, or heart, and nonultracentral tumors. Cohorts were compared with respect to grade ≥ 2 toxicity, progression-free survival (PFS), and overall survival (OS).

RESULTS

In total, 41 patients with 45 ultracentral metastases and 93 patients with 172 nonultracentral metastases underwent SABR. The most common primary histologies were colorectal (30%), lung (13%), and renal (13%), and these did not differ between groups. Patients with UC had a lower median PFS of 5.8 months compared with 15.8 months in patients with non ultracentral tumors (P < .001). OS was also worse in the UC cohort: median 29.0 months versus not yet reached (P < .001). On multivariable regression, UC remained prognostic for worse PFS (hazard ratio 2.18, P = .004) and OS (hazard ratio 3.45, P < .001). Groups had similar rates of local tumor control. Patients with UC had higher 2-year cumulative incidence of polymetastatic progression: 69.2% versus 31.4% (P < .001). The 2-year cumulative incidence of grade ≥ 2 toxicity was 14.6% for patients with UC and 9.8% for patients with nonultracentral tumors (P = .74). There were no grade 4 or 5 toxicities.

CONCLUSIONS

In this prospective patient cohort, SABR for ultracentral tumor had low toxicity rates and good local control. However, ultracentral location was an adverse prognostic feature for survival. This finding should be validated with larger studies and may be a factor when weighing the benefit versus risk of SABR in patients with pulmonary oligometastases.

Radiological precursor lesions of lung squamous cell carcinoma: Early progression patterns and divergent volume doubling time between hilar and peripheral zones

OBJECTIVES

This study investigated the early progression patterns of lung squamous cell carcinoma (SqCC) on computed tomography (CT) images.

MATERIALS AND METHODS

In total, 65 patients with SqCC who underwent surgical resection and two CT scans separated by an interval of at least 6 months were enrolled. We categorized the findings of the initial and at-diagnosis CT images into five patterns as previously reported. The volume doubling time (VDT) was calculated for measurable lesions.

RESULTS

A single nodule pattern on CT images at-diagnosis was most common in 56 (86.2 %) patients, in line with practical clinical findings. However, the patterns were diverse in the initial images, with 28 (43.1 %) patients displaying atypical findings, including multiple nodules (3.1 %), endobronchial lesions (20.0 %), subsolid nodules (10.8 %), and cyst wall thickening (9.2 %). All endobronchial lesions were located in the central/middle zone of the lung field, whereas lesions presented as multiple nodules, subsolid nodules, and cyst wall thickening were predominantly observed in the peripheral zone. The differences in the developed zones were reflected in the median VDT, and the tumors with an initial endobronchial pattern had a significantly shorter VDT than those with a subsolid nodule pattern (median: 140 days vs 276 days, p < 0.001).

CONCLUSIONS

Lung SqCC initiated with various CT image patterns, although most tumors ultimately developed a single nodule pattern by diagnosis. The initial CT image patterns differed between the hilar and peripheral zones, suggesting a difference in the progression scheme, which was also supported by differences in VDT.

Selection of the surgical approach for patients with cStage IA lung squamous cell carcinoma: A population-based propensity score matching analysis

Background

This study aimed to conduct a comparative analysis of the survival rates after segmentectomy, wedge resection, or lobectomy in patients with cStage IA lung squamous cell carcinoma (SCC).

Methods

We enrolled 4,316 patients who had cStage IA lung SCC from the Surveillance, Epidemiology, and End Results (SEER) database. The Cox proportional hazards model was conducted to recognize the potential risk factors for overall survival (OS) and lung cancer-specific survival (LCSS). To eliminate potential biases of included patients, the propensity score matching (PSM) method was used. OS and LCSS rates were compared among three groups stratified according to tumor size.

Results

Kaplan–Meier analyses revealed no statistical differences in the rates of OS and LCSS between wedge resection (WR) and segmentectomy (SG) groups for patients who had cStage IA cancers. In patients with tumors ≤ 1 cm, LCSS favored lobectomy (Lob) compared to segmentectomy (SG), but a similar survival rate was obtained for wedge resection (WR) and lobectomy (Lob). For patients with tumors sized 1.1 to 2 cm, lobectomy had improved OS and LCSS rates compared to the segmentectomy or wedge resection groups, with the exception of a similar OS rate for lobectomy and segmentectomy. For tumors sized 2.1 to 3 cm, lobectomy had a higher rate of OS or LCSS than wedge resection or segmentectomy, except that lobectomy conferred a similar LCSS rate compared to segmentectomy. Multivariable analyses showed that patients aged ≥75 and tumor sizes of &gt;2 to ≤3 cm were potential risk factors for OS and LCSS, while lobectomy and first malignant primary indicator were considered protective factors. The Cox proportional analysis also confirmed that male patients aged ≥65 to &lt;75 were independent prognostic factors that are indicative of a worse OS rate.

Conclusions

The tumor size can influence the surgical procedure recommended for individuals with cStage IA lung SCC. For patients with tumors ≤1 cm, lobectomy is the recommended approach, and wedge resection or segmentectomy might be an alternative for those who cannot tolerate lobectomy if adequate surgical margin is achievable and enough nodes are sampled. For tumors &gt;1 to ≤3 cm, lobectomy showed better survival outcomes than sublobar resection. Our findings require further validation by randomized controlled trial (RCT) or other evidence.

Primary tumor location in lung cancer: the evaluation and administration

ABSTRACT

Lung cancer continues to be the leading cause of cancer-related death in the world, which is classically subgrouped into two major histological types: Non-small cell lung cancer (NSCLC) (85% of patients) and small-cell lung cancer (SCLC) (15%). Tumor location has been reported to be associated with the prognosis of various solid tumors. Several types of cancer often occur in a specific region and are more prone to spread to predilection locations, including colorectal cancer, prostate cancer, gastric cancer, ovarian cancer, cervical cancer, bladder cancer, lung tumor, and so on. Besides, tumor location is also considered as a risk factor for lung neoplasm with chronic obstructive pulmonary disease/emphysema. Additionally, the primary lung cancer location is associated with specific lymph node metastasis. And the recent analysis has shown that the primary location may affect metastasis pattern in metastatic NSCLC based on a large population. Numerous studies have enrolled the "location" factor in the risk model. Anatomy location and lobe-specific location are both important in prognosis. Therefore, it is important for us to clarify the characteristics about tumor location according to various definitions. However, the inconsistent definitions about tumor location among different articles are controversial. It is also a significant guidance in multimode therapy in the present time. In this review, we mainly aim to provide a new insight about tumor location, including anatomy, clinicopathology, and prognosis in patients with lung neoplasm.

Predicting Incomplete Resection in Non-Small Cell Lung Cancer Preoperatively: A Validated Nomogram

BACKGROUND

Patients who are surgically treated for stage I to III non-small cell lung cancer (NSCLC) have dismal prognosis after incomplete (R1-R2) resection. Our study aimed to develop a prediction model to estimate the chance of incomplete resection based on preoperative patient-, tumor-, and treatment-related factors.

METHODS

From a Dutch national cancer database, NSCLC patients who had surgical treatment without neoadjuvant therapy were selected. Thirteen possible predictors were analyzed. Multivariable logistic regression was used to create a prediction model. External validation was applied in the American National Cancer Database, whereupon the model was adjusted. Discriminatory ability and calibration of the model was determined after internal and external validation. The prediction model was presented as nomogram.

RESULTS

Of 7156 patients, 511 had an incomplete resection (7.1%). Independent predictors were histology, cT stage, cN stage, extent of surgery, and open vs thoracoscopic approach. After internal validation, the corrected C statistic of the resulting nomogram was 0.72. Application of the nomogram to an external data set of 85,235 patients with incomplete resection in 2485 patients (2.9%) resulted in a C statistic of 0.71. Calibration revealed good overall fit of the nomogram in both cohorts.

CONCLUSIONS

An internationally validated nomogram is presented providing the ability to predict the individual chance of incomplete resection in patients with stage I to III NSCLC planned for resection. In case of a high predicted risk of incomplete resection, alternative treatment strategies could be considered, whereas a low risk further supports the use of surgical procedures.

Peripheral type squamous cell carcinoma of the lung: clinicopathologic characteristics in comparison to the central type

BACKGROUND

Squamous cell carcinomas (SqCCs) of the lung are known to arise more often in a central area but reports of peripheral SqCCs have increased, with a pathogenesis that is obscured. In this study, the clinicopathologic characteristics of peripheral lung SqCCs were studied and compared with those of the central type.

METHODS

This study included 63 peripheral lung SqCCs and 48 randomly selected central cases; hematoxylin and eosin-stained slides of surgically resected specimens were reviewed in conjunction with radiologic images and clinical history. Cytokeratin-7 immunohistochemical staining of key slides and epidermal growth factor receptor (EGFR)/KRAS mutations tested by DNA sequencing were also included.

RESULTS

Stages of peripheral SqCCs were significantly lower than central SqCCs (p=.016). Cystic change of the mass (p=.007), presence of interstitial fibrosis (p=0.007), and anthracosis (p=.049) in the background lung were significantly associated with the peripheral type. Cytokeratin-7 positivity was also higher in peripheral SqCCs with cutoffs of both 10% and 50% (p=.011). Pathogenic mutations in EGFR and KRAS were observed in only one case out of the 72 evaluated. The Cox proportional hazard model indicated a significantly better disease-free survival (p=.009) and the tendency of better overall survival (p=.106) in the peripheral type.

CONCLUSIONS

In peripheral type, lower stage is a favorable factor for survival but more frequent interstitial fibrosis and older age are unfavorable factors. Multivariate Cox analysis revealed that peripheral type is associated with better disease-free survival. The pathogenesis of peripheral lung SqCCs needs further investigation, together with consideration of the background lung conditions.

Integrated evaluation of clinical, pathological and radiological prognostic factors in squamous cell carcinoma of the lung

Objective

Little is known about prognostic factors for lung squamous cell carcinoma (SCC). We aimed to explore radiologic and clinical factors affecting prognosis and to compare the prognosis of both central and peripheral lung SCCs.

Materials and methods

Radiologic, clinical, and pathologic profiles of surgically confirmed SCCs from 382 patients were retrospectively reviewed. Tumor location, enhancement, necrosis, the presence of obstructive pneumonitis/atelectasis and underlying lung disease were evaluated on chest CT examination. Age, pulmonary function, tumor marker, and cancer stage were also assessed. Univariate and multivariate Cox regression analyses were performed to identify any correlation to overall survival (OS) and disease-free survival (DFS). Hazard rate estimation and competing risk analysis were done to evaluate recurrence pattern.

Results

The median follow-up period was 56.2 months. Tumors were located centrally in 230 patients (60.2%) and peripherally in 152 patients (39.8%). Age (p = 0.002, hazard ratio [HR] 1.03, 95% confidence interval [CI] = [1.01, 1.06]) and interstitial lung abnormalities (ILAs) (p<0.001, HR 5.41, 95% CI = [3.08, 9.52]) were associated with poor OS on multivariate analysis. ILAs also had a strong association to DFS (p<0.001, HR 4.25, 95% CI = [3.08, 9.52]). Central cancers had two peaks of local recurrence development at 15 and 60 months after surgery, and peripheral tumors showed rising curves for metastasis development at 60 months.

Conclusions

CT-determined ILAs are a strong biomarker predicting poor outcome. Prognosis may not vary according to tumor location, but the two groups exhibited different recurrence patterns.

Growth patterns of small peripheral squamous cell carcinoma of the lung and their impacts on pathological and biological characteristics of tumor cells

PURPOSE

The growth pattern of peripheral squamous cell carcinoma (SCC) of the lung is divided into two types: alveolar space-filling (ASF) growth and alveolar space-destructive (ASD) growth. The aim of this study was to investigate the clinicopathological differences between cancer cells displaying ASF and ASD growth.

METHODS

We analyzed 155 patients with peripheral SCC measuring 30 mm or less in diameter. The proportion of ASF in the total tumor area (%ASF) was determined using digital image analysis. We examined the clinicopathological characteristics of the cancer cells and compared the immunophenotypes of high %ASF tumors (> 30%) and low %ASF tumors (0%). Finally, we analyzed the prognostic impact of ASD area with small SCC cases (≤ 2.0 cm, n = 72).

RESULTS

Cases of high %ASF tumors showed significantly lower frequencies of lymphovascular invasion (p = 0.008). Immunohistochemical staining revealed that the expression score of laminin-5, invasive-related molecule, in cancer cells was significantly lower in high %ASF cases than in low %ASF cases (p = 0.001). Within the same tumor, laminin-5 expression in the ASF area was significantly lower than that in the ASD area (p = 0.001). The overall 5-year survival rate of patients with a larger ASD area (> 1.0 cm2) was significantly lower than that of patients with a smaller ASD area (≤ 1.0 cm2) (p = 0.017).

CONCLUSIONS

In this study, we clearly showed that cancer cells presenting with ASF represents a "less invasive phenotype" in peripheral SCC.

Choice of the surgical approach for patients with stage I lung squamous cell carcinoma ≤3 cm

Background

We tried to explore the surgical procedures for stage I squamous cell carcinoma (SCC) with a size of ≤3 cm by using the Surveillance, Epidemiology, and End Results (SEER) database. Furthermore, we investigated the relationships between the chosen surgical option and the size of SCC.

Methods

In total, 1,147 patient data sets were collected from 2010 to 2011 using the SEER database. Afterwards, 849 patients with a pT1-2aN0M0 SCC with a size of ≤3 cm after a lobectomy or sublobectomy procedure were identified. Kaplan-Meier curves were conducted to compare the overall survival (OS) rates and the lung cancer-specific survival (LCSS) rates between the two surgical approaches. Cox proportional hazards regressions were performed to discover the independent risk factors for both the OS and LCSS rates. Lastly, subgroup analysis was stratified by the size of the SCC and then classified by the 8^th edition T category.

Results

The sublobectomy procedure did not demonstrate a difference for the OS rate. Additionally, it demonstrated a worse LCSS rate when compared with a lobectomy for stage I SCC. In the subgroup analysis, a lobectomy was shown to have a better survival outcome only when the SCC was >2 and ≤3 cm. Multivariable analysis showed that a size of >2 to ≤3 cm, and an age of >60 were independently associated with poorer OS while the sublobectomy procedure and pleural invasions (PI) were related with a poorer LCSS rate. In the stratification of data for the tumor size, the cox proportional analysis still confirmed the protective effects of the lobectomy in subgroups of SCCs with sizes between >2 to ≤3 cm as well as the T1c category.

Conclusions

The choice of the SCC surgery can be recommended based on the tumor size. A lobectomy procedure demonstrated a better LCSS against the sublobectomy in stage I SCC. SCC with sizes of >2 to ≤3 cm could become a pretty good indicator for lobectomy, while a sublobectomy may be an adequate substitute when the SCC size is ≤2 cm, especially for patients who cannot tolerate a lobectomy. T1c category can also suggest a lobectomy instead of sublobectomy for stage I SCC patients.

The Differences in Clinicopathologic and Prognostic Characteristics Between Surgically Resected Peripheral and Central Lung Squamous Cell Carcinoma

BACKGROUND

Pulmonary peripheral-type squamous cell carcinoma (p-SqCC) has been increasing in incidence. However, little is known about the clinicopathologic features of p-SqCC. This study aimed to investigate the clinicopathologic characteristics and clinical outcomes of p-SqCC compared with central-type SqCC (c-SqCC) in a large cohort of surgically resected lung SqCC patients with long-term follow-up results.

METHODS

The study included 268 patients with SqCC who underwent surgical resection at the authors' institute from January 1990 to September 2013. The mean follow-up period was 67.1 months. The clinicopathologic and genetic characteristics were investigated in relation to their association with progression-free survival (PFS) and overall survival (OS) based on tumor location.

RESULTS

The study cohort included 120 patients with p-SqCC and 148 patients with c-SqCC. Compared with c-SqCC, p-SqCC was correlated with older age (p = 0.002), female sex (p = 0.033), better performance status (p < 0.001), smaller tumor (p = 0.004), less lymph node metastasis (p < 0.001), and an earlier pathologic stage (p < 0.001). Despite the clinicopathologic differences, tumor location was not significantly correlated with clinical outcomes. For the p-SqCC patients, the multivariate analysis showed a significant correlation of lymphovascular invasion (PFS, p < 0.001; OS, p < 0.001) and lymph node metastasis (p = 0.007; OS, p = 0.022) with poor PFS and OS, but a significant correlation of incomplete tumor resection (PFS, p = 0.009) only with poor PFS.

CONCLUSIONS

The clinicopathologic features differed between the p-SqCC and c-SqCC patients. Lymphovascular invasion and lymph node metastasis were independent prognostic factors of p-SqCC. These prognostic factors may be potentially used as indicators for adjuvant therapies to be used with patients who have p-SqCC.

Comprehensive investigation of clinicopathologic features, oncogenic driver mutations and immunohistochemical markers in peripheral lung squamous cell carcinoma

Background

Although the majority of lung squamous cell carcinomas (SQCC) arise in central airways, the prevalence of peripheral (p) SQCC is increasing. This study aimed to have a comprehensive investigation of clinicopathologic features, status of common driver mutations and immunophenotypes of p-SQCC compared to central (c) SQCC.

Methods

A total of 261 p-SQCC were compared to 444 c-SQCC for clinicopathologic characteristics. Comprehensive mutational analysis of EGFR, KRAS, HER2, BRAF, PIK3CA, DDR2, AKT1, ALK, ROS1, RET and FGFRs were performed. TTF1, CK7, Napsin A and PE10 protein expression were analyzed through immunohistochemistry (IHC). TTF1, CK7, CK8, SPA and TP63 gene expression levels were measured by quantitative real-time PCR.

Results

Compared to c-SQCC, p-SQCC were associated with female (14.2% vs. 4.5%, P<0.001), never-smokers (22.6% vs. 13.3%, P=0.001), older age at diagnosis (64.9 vs. 59.5 years, P<0.001) and lower pathologic stage (P<0.001). The frequency of EGFR mutations was significantly higher in p-SQCC than c-SQCC (6.2% vs. 2.2%, P=0.040). Positive protein expression of TTF1 (P=0.010) and CK7 (P=0.001) was significantly more prevalent in p-SQCC. p-SQCC had significantly higher gene expression of SPA (P=0.003), whereas c-SQCC showed higher gene expression of TP63 (P=0.028).

Conclusions

Lung p-SQCC had distinctive clinicopathologic characteristics and molecular features compared to c-SQCC, but showed some similarity with adenocarcinoma (ADC).

Clinical Prognosis of Superior Versus Basal Segment Stage I Non-Small Cell Lung Cancer

BACKGROUND

Despite its extensive size, variations in the clinicopathologic features of tumors in the lower lobe have been little studied. The present study investigated the prognostic differences in tumors originating from the superior and basal segments of the lower lobe in patients with non-small cell lung cancer.

METHODS

Data of 134 patients who underwent lobectomy or segmentectomy with systematic nodal dissection for clinical stage I, radiologically solid-dominant, non-small cell lung cancer in the superior segment (n = 60) or basal segment (n = 74) between April 2007 and December 2015 were retrospectively reviewed. Factors affecting survival were assessed by the Kaplan-Meier method and Cox regression analyses.

RESULTS

Prognosis in the superior segment group was worse than that in the basal segment group (5-year overall survival rates 62.6% versus 89.9%, p = 0.0072; and 5-year recurrence-free survival rates 54.4% versus 75.7%, p = 0.032). In multivariable Cox regression analysis, a superior segment tumor was an independent factor for poor overall survival (hazard ratio 3.33, 95% confidence interval: 1.22 to 13.5, p = 0.010) and recurrence-free survival (hazard ratio 2.90, 95% confidence interval: 1.20 to 7.00, p = 0.008). The superior segment group tended to have more pathologic mediastinal lymph node metastases than the basal segment group (15.0% versus 5.4%, p = 0.080).

CONCLUSIONS

Tumor location was a prognostic factor for clinical stage I non-small cell lung cancer in the lower lobe. Patients with superior segment tumors had worse prognosis than patients with basal segment tumors, with more metastases in mediastinal lymph nodes.

Nonsmall cell lung carcinoma: diagnostic difficulties in small biopsies and cytological specimens

The pathological and molecular classification of lung cancer has become substantially more complex over the past decade. For diagnostic purposes on small samples, additional stains are frequently required to distinguish between squamous cell carcinoma and adenocarcinoma. Subsequently, for advanced nonsquamous cell nonsmall cell lung carcinoma (NSCLC) patients, predictive analyses on epidermal growth factor receptor, anaplastic lymphoma kinase and ROS1 are required. In NSCLCs negative for these biomarkers, programmed death ligand-1 immunohistochemistry is performed. Small samples (biopsy and cytology) require “tissue” management, which is best achieved by the interaction of all physicians involved.

Differing histopathology and prognosis in pulmonary adenocarcinoma at central and peripheral locations

BACKGROUND

Pulmonary adenocarcinoma is largely peripheral in location but often does occur centrally. In the course of this study, clinicopathologic features of pulmonary adenocarcinoma, including the prognosis of early-stage disease, were assessed and compared by tumor location.

METHODS

A retrospective chart review was conducted, examining 308 patients treated for pulmonary adenocarcinoma by curative resection. Clinicopathologic findings were analyzed, comparing central and peripheral primary locations. Recurrence-free survival (RFS) rates were determined for tumor subsets (central vs. peripheral).

RESULTS

At all disease stages (N=308), 41 patients (13.3%) with central adenocarcinoma were documented. In central (vs. peripheral) adenocarcinoma, mean tumor size was larger (3.1 vs. 2.3 cm, P=0.014), nodal metastasis was more frequent (P=0.012), and the likelihood of advanced disease (stages II and III) was greater (P=0.007). Microscopically, central adenocarcinoma displayed more acinar (53.3% vs. 38.9%; P=0.006) and less lepidic (20.9% vs. 37.5%; P=0.001) growth. At stage I disease [N=329; central, 25 (10.5%)], group similarities were sustained. As with disease overall, central adenocarcinoma contained more acinar (51.8% vs. 37.1%; P=0.025) and fewer lepidic (26.2% vs. 44.1%; P=0.006) areas. Three-year RFS rates for central and peripheral adenocarcinoma at all disease stages were 63.2% and 82.5% (P=0.024), respectively, compared with 70.4% and 91.0% (P=0.023), respectively at stage I. Lepidic growth was identified as a statistically significant risk factor for early recurrence by multivariate analysis.

CONCLUSIONS

Central pulmonary adenocarcinoma is generally detected at an advanced stage. In early (stage I) disease, the prognosis is comparatively worse for central adenocarcinoma, owing to significant micromorphologic differences in central and peripheral tumors.

Prognostic factors based on clinicopathological data among the patients with resected peripheral squamous cell carcinomas of the lung

INTRODUCTION

Although the incidence of peripheral squamous cell carcinomas (p-SqCCs) of the lung has increased over recent years, clinicopathological factors influencing prognosis of resected p-SqCCs remain unclear.

METHODS

We examined 280 patients who underwent complete resection of SqCCs and analyzed the clinicopathological features in relation to their overall survival (OS) and recurrence-free survival (RFS) according to the primary location.

RESULTS

Multivariate analysis of all stages of p-SqCCs patients revealed that high serum squamous cell carcinoma antigen (SCC) level (OS; p < 0.01, RFS; p < 0.01), vascular invasion (OS; p < 0.01, RFS; p < 0.01), pleural invasion (OS; p = 0.03, RFS; p = 0.01), nodal metastasis (OS; p = 0.02) and complication with lung disease (OS; p < 0.01) were independently unfavorable prognostic factors. Among stage I p-SqCCs patients, high serum SCC level (OS; p < 0.01, RFS; p < 0.01), vascular invasion (RFS; p < 0.01) and pleural invasion (RFS; p = 0.01) were also strongly correlated with poor prognosis independently. When we reevaluated the survival rate, T1 p-SqCCs with high serum SCC level or vascular invasion can be upgraded to T2a. Patients with stage IB had a significantly poorer prognosis than stage IA (5-year RFS; 61.4 % versus 76.6 %, p < 0.05).

CONCLUSION

High serum SCC level, pleural and vascular invasions were independent poor prognostic factors for completely resected p-SqCCs. T1 p-SqCCs with high serum SCC level or vascular invasion should be upgraded to T2a, which accurately reflect survival status among patients with p-SqCCs.

A clinicopathological study of resected small-sized squamous cell carcinomas of the peripheral lung: prognostic significance of serum carcinoembryonic antigen levels

PURPOSE

The purpose of this retrospective study was to evaluate common clinicopathological factors and clarify the prognostic factors of small-sized peripheral-lung squamous cell carcinomas.

METHODS

We retrospectively reviewed 71 patients with peripheral squamous cell carcinoma ≤3 cm in diameter, who were surgically treated between January 1989 and December 2010. Patients undergoing partial lung resection without lymph node dissection were excluded. The median follow-up for living patients was 63 months.

RESULTS

The overall 3- and 5-year survival rates were 83.9% and 74.7%, respectively.Although the ROC curve of serum carcinoembryonic antigen (CEA) levels showed marginally significance (P = 0.050), multivariate analyses revealed that age (P = 0.043), lymph node metastasis (P = 0.004), and preoperative serum carcinoembryonic antigen (CEA) level (P = 0.037) were independent prognostic factors. For pathologic N0 patients, there was a significant difference for recurrence-free survival based on CEA levels: patients with normal CEA levels (n = 40), 5-year-recurrence-free rate = 93.5%;elevated CEA (n = 14), 5-year-recurrence-free rate = 72.7% (P = 0.0160). The distribution of tumor cells immunoreactive for CEA was significantly associated with serum CEA levels (P = 0.033).

CONCLUSION

Age, lymph node metastasis, and serum CEA level are independent prognostic factors for small-sized peripheral-lung squamous cell carcinoma.

Morphologic and clinicopathologic features of lung squamous cell carcinomas expressing Sox2

Sox2 amplification was recently reported as a common event in squamous cell carcinomas (SCCs) occurring at different anatomic sites including the lung. The objective of the study was to determine morphologic and clinicopathologic characteristics of lung SCCs with respect to Sox2 protein expression and gene amplification. One hundred forty-seven surgically treated non-small cell lung carcinomas were analyzed for Sox2 gene amplification by using fluorescence in situ hybridization and protein expression using immunohistochemical analysis. SCC showed more frequent Sox2 protein expression (52/66; 79%) than adenocarcinomas (ADC) (14/76; 18%) (P < .0001). Similarly, Sox2 amplification was more frequent in SCCs (52/70; 72%) than in ADCs (6/77; 8%) (P < .0001). Sox2 protein expression was associated with better overall survival in SCC (66 vs 14 months; P =.048). SCC with basaloid differentiation and severe nuclear atypia exhibited more intense Sox2 protein expression than other tumors. Sox2 appears to be an important gene in lung squamous cell carcinogenesis that in particular drives the development of poorly differentiated tumors.

Immunohistochemical algorithm for differentiation of lung adenocarcinoma and squamous cell carcinoma based on large series of whole-tissue sections with validation in small specimens

Immunohistochemistry is increasingly utilized to differentiate lung adenocarcinoma and squamous cell carcinoma. However, detailed analysis of coexpression profiles of commonly used markers in large series of whole-tissue sections is lacking. Furthermore, the optimal diagnostic algorithm, particularly the minimal-marker combination, is not firmly established. We therefore studied whole-tissue sections of resected adenocarcinoma and squamous cell carcinoma (n=315) with markers commonly used to identify adenocarcinoma (TTF-1) and squamous cell carcinoma (p63, CK5/6, 34βE12), and prospectively validated the devised algorithm in morphologically unclassifiable small biopsy/cytology specimens (n=38). Analysis of whole-tissue sections showed that squamous cell carcinoma had a highly consistent immunoprofile (TTF-1-negative and p63/CK5/6/34βE12-diffuse) with only rare variation. In contrast, adenocarcinoma showed significant immunoheterogenetity for all 'squamous markers' (p63 (32%), CK5/6 (18%), 34βE12 (82%)) and TTF-1 (89%). As a single marker, only diffuse TTF-1 was specific for adenocarcinoma whereas none of the 'squamous markers,' even if diffuse, were entirely specific for squamous cell carcinoma. In contrast, coexpression profiles of TTF-1/p63 had only minimal overlap between adenocarcinoma and squamous cell carcinoma, and there was no overlap if CK5/6 was added as a third marker. An algorithm was devised in which TTF-1/p63 were used as the first-line panel, and CK5/6 was added for rare indeterminate cases. Prospective validation of this algorithm in small specimens showed 100% accuracy of adenocarcinoma vs squamous cell carcinoma prediction as determined by subsequent resection. In conclusion, although reactivity for 'squamous markers' is common in lung adenocarcinoma, a two-marker panel of TTF-1/p63 is sufficient for subtyping of the majority of tumors as adenocarcinomas vs squamous cell carcinoma, and addition of CK5/6 is needed in only a small subset of cases. This simple algorithm achieves excellent accuracy in small specimens while conserving the tissue for potential predictive marker testing, which is now an essential consideration in advanced lung cancer specimens.

Mixed Adenocarcinomas of the Lung: Place in New Proposals in Classification, Mandatory for Target Therapy

Context.—Lung cancer is one of the most frequent and lethal malignant neoplasms, but knowledge regarding the molecular basis of its pathogenesis is far from complete due to the striking diversity of different forms. The current lung cancer classification (World Health Organization 2004) can efficiently distinguish clinically relevant major subtypes (small cell and non–small cell carcinomas), but its results are partly inadequate when facing prognostic and therapeutic decisions for non–small cell carcinomas, especially for the group of tumors classified as adenocarcinoma. Lung adenocarcinoma comprises a heterogeneous group of tumors characterized by diverse morphologic features and molecular pathogenesis. The category of mixed adenocarcinomas includes most adenocarcinomas (approximately 80%) and, according to World Health Organization criteria, is defined by the occurrence of a mixed array of different patterns (acinar, papillary, bronchioloalveolar, solid with mucin). The histologic recognition of mixed adenocarcinoma is subjective and cannot consistently discriminate between responders and nonresponders to new targeted therapies (eg, tyrosine kinase inhibitors). Diagnostic problems are mainly related to the poor reproducibility of histologic criteria, especially when applied in small biopsies and cytology, and to the difficulty in assigning each form to a precisely defined entity, as needed by updated therapeutic approaches. In this evolving scenario, pathologists face new challenging diagnostic roles that include not only the precise morphologic definition of carcinoma subtypes but also their molecular characterization.

Objective.—To use a comprehensive critical analysis reconciling the overwhelming variety of biologic, morphologic, molecular, and clinical data to define new classification schemes for lung adenocarcinoma.

Data Sources.—Scientific literature and personal data were used.

Conclusions.—A new classification approach should redefine lung adenocarcinoma heterogeneity reconciling classic morphology, immunophenotypic and molecular features of neoplastic cells, and also relevant information provided by stem cell biology. This approach, which has been already successfully applied in World Health Organization classification of other tumors, could improve the recognition of new reproducible profiles for adenocarcinomas, more closely and reproducibly related to clinical features and response to specific therapies, limiting the use of “wastebasket” categories such as mixed adenocarcinoma.

Immunohistochemical differential diagnosis between thymic carcinoma and type B3 thymoma: diagnostic utility of hypoxic marker, GLUT-1, in thymic epithelial neoplasms

There are only a few immunohistochemical markers that are useful for differentiating thymic carcinomas from type B3 thymomas. The purpose of this study is to examine the additional markers that would be useful for differentiating between thymic carcinoma and thymoma type B3. We performed a tissue microarray analysis of surgically resected thymic tumor specimens from 12 cases of thymic carcinoma, 7 cases of type B3 thymoma, and 68 cases of other types of thymoma. Immunostaining using 49 antibodies was scored based on staining intensity and the percentage of cells that stained positive. Seven proteins that were selected by the staining scores, namely, GLUT-1 (167 vs 4), CA-IX (110 vs 15), c-kit (162 vs 44), CD5 (33 vs 0), MUC-1 (54 vs 0), CEA (42 vs 0), and CK18 (110 vs 42), were significantly higher in the thymic carcinomas than in the type B3 thymomas. The staining sensitivity and specificity of the antibodies for thymic carcinoma were GLUT-1, sensitivity 72% and specificity 100%; CA-IX, 58 and 71%; c-kit, 72 and 85%; CD5, 33 and 100%; CK18, 58 and 71%; MUC-1, 25 and 100%; and CEA, 33 and 100%. Glucose transporter 1 (GLUT-1) is the best marker for thymic carcinoma because it had the highest sensitivity and specificity. Positive immunostaining for a combination of three markers, namely, GLUT-1, CD5, and CEA, enabled differentiation of thymic carcinoma with 91.6% sensitivity and 100% specificity. In conclusion, we identified GLUT-1 as an additional marker that will be useful for differentiating thymic carcinoma from type B3 thymoma, especially in biopsy specimens that have been crushed or are otherwise difficult to examine morphologically in thymic tumors.

Forkhead box M1 expression in pulmonary squamous cell carcinoma: correlation with clinicopathologic features and its prognostic significance

Forkhead box M1 (FoxM1) transcription factor has been shown to play important roles in regulating the expression of genes that are involved in cell proliferation, differentiation, and transformation by promoting both G(1)/S and G(2)/M transition. Although it has been reported that the FoxM1 signaling network is frequently deregulated with an up-regulated FoxM1 expression in human malignancies, the role of FoxM1 in lung cancer remains to be determined. We performed immunohistochemical detection of FoxM1 protein in 69 tissue samples from patients with primary pulmonary squamous cell carcinoma using a tissue microarray, and Western blotting was done to confirm the immunohistochemical observations. FoxM1 immunoreactivity was observed in 26 (37.7%) of the 69 squamous cell carcinoma cases. Analysis of the FoxM1 expression in 12 squamous cell carcinoma tissues and 2 normal lung tissues by Western blotting confirmed the immunohistochemical results. A FoxM1 expression was more frequently detected in the moderately or poorly differentiated squamous cell carcinomas than in the well-differentiated squamous cell carcinomas (P = .008). The tumors with a positive FoxM1 expression more frequently showed lymph node metastasis (P = .027) and an advanced American Joint Committee on Cancer stage (P = .049). The Kaplan-Meier survival curves demonstrated that patients with a positive FoxM1 expression had a significantly shorter survival time than those patients with a negative FoxM1 expression (P = .003). The multivariate analysis revealed that the FoxM1 expression was an independent poor prognostic factor (P = .018). A subset of pulmonary squamous cell carcinoma with a FoxM1 expression was associated with progressive pathologic features and an aggressive clinical course.