Clinicopathological characteristics of EGFR mutated adenosquamous carcinoma of the lung

Clinicopathological characteristics and prognosis of resectable lung adenosquamous carcinoma: a population-based study of the SEER database

OBJECTIVE

Adenosquamous carcinoma is a rare subtype of non-small cell lung cancer characterized by aggressive behavior, with combination of adenocarcinoma and squamous cell carcinoma components. The clinicopathological characteristics and prognosis of resectable adenosquamous carcinoma are incompletely understood and this study aimed to depict those in a large population.

METHODS

A total of 805 adenosquamous carcinoma, 7875 squamous cell carcinoma and 23 957 adenocarcinoma patients who underwent lobectomy or sublobectomy were queried from the Surveillance, Epidemiology, and End Results database (2010-17). Clinicopathological characteristics of adenosquamous carcinoma patients were compared with those of squamous cell carcinoma and adenocarcinoma patients. Prognostic factors were identified by univariable and multivariable Cox regression analyses. Propensity score matching was applied to reduce confounding effects.

RESULTS

Adenosquamous carcinoma was associated with higher pleural invasion incidence and poorer differentiation compared with squamous cell carcinoma or adenocarcinoma (P values < 0.001). The independent risk factors of cancer-specific survival of adenosquamous carcinoma patients were increasing age, male sex, invading through visceral pleura, poor differentiation and higher stage. Stage IB adenosquamous carcinoma patients whose tumor invaded through visceral pleura had significantly worse survival than those not (P = 0.003). Adenosquamous carcinoma patients had worse survival compared with squamous cell carcinoma (5-year-survival: 64.55 vs. 69.09%, P = 0.003) and adenocarcinoma (5-year-survival: 64.55 vs. 76.79%, P < 0.001) patients before match. And this difference persisted after match.

CONCLUSIONS

Resectable adenosquamous carcinoma patients had higher pleural invasion incidence, poorer differentiation and worse survival compared with squamous cell carcinoma and adenocarcinoma patients. Visceral pleural invasion status and differentiation grade were vital prognostic factors of adenosquamous carcinoma patients on the basis of stage.

A nomogram to predict prognosis of patients with lung adenosquamous carcinoma: a population-based study

Background

Adenosquamous carcinoma (ASC) of the lung is an infrequent variant of lung cancer. This study aimed to identify independent risk factors and to develop a predictive model for the prognosis of ASC patients.

Methods

Patient data were extracted from the Surveillance, Epidemiology, and End Results (SEER) database (2004 to 2016) and database in our department (2010 to 2014). Overall survival (OS) was evaluated by the Kaplan-Meier method. Significant prognostic factors were identified by univariate analysis (UVA) and multivariate analysis (MVA) using the Cox proportional hazards regression. Competing risk model analyses were performed using cancer-specific survival outcomes. A nomogram was developed to predict patient 3-year and 5-year OS and was validated using data from the two databases.

Results

A total of 4,600 patients with ASC were included and divided into a training cohort (n=3,202) and two validation cohorts (n=1,372, n=26). Patients with ASC had significantly older age, lower grades of tumor differentiation or incidences of nodal, and distant invasions than adenocarcinoma and squamous cell carcinoma (SCC) of the lung (P<0.001), while the median survival time of ASC patients was intermediate [21.0 (19.3-22.7) months]. Age, sex, primary site of tumor, histological grade, T stage, N stage, M stage of the tumor, as well as surgery to the primary tumor site and chemotherapy were identified as independent factors for ASC (P<0.001). A reliable nomogram was established with a group of validation plots and concordance indices (C-indices) (internal: 0.755±0.010; external: 0.748±0.049 and 0.721±0.045).

Conclusions

Age, sex, primary site of tumor, histological grade, T stage, N stage, M stage of the tumor, as well as surgery to the primary site of tumors and chemotherapy were independent risk factors for ASC patients. A validated nomogram was constructed to predict the prognosis based on the patient clinical characteristics.

Adenocarcinomatous-predominant subtype associated with a better prognosis in adenosquamous lung carcinoma

Background

According to the proportion of glandular and squamous pathological components, adenosquamous carcinoma (ASC) could be divided into adenocarcinoma (AC) and squamous cell carcinoma (SCC) predominant subtypes. Due to its rarity, no study investigating the impact of different subtypes on the clinical features, radiologic findings and prognosis characteristics of ASC has been reported.

Methods

Sixty eight patients who underwent surgical resection for lung adenosquamous carcinoma in our institute between January 2006 and March 2017 were retrospectively reviewed. Data regarding the clinical features, radiologic findings and prognosis characteristics were collected.

Results

Thirty nine patients of the study cohort were with AC-predominant ASC and 29 with SCC-predominant ASC. There was no significant difference between the two subgroups in age, gender, smoking history, serum carcinoembryonic antigen (CEA) level and T,N classification. Air bronchogram was found more frequently in AC-predominant ASC than in SCC-predominant ASC (P = 0.046). Multivariate analysis identified pathological subtype (P = 0.022) and CT findings of peripheral location (P = 0.009) to be independent prognostic factors.

Conclusions

AC-predominant ASC were more commonly presented with air bronchogram, and were with a better prognosis than SCC-predominant ASC.

Treatment for Patients With Early Stage Adenosquamous Lung Cancer

Introduction

Adenosquamous lung cancer (ASC) is a rare type of NSCLC with poor prognosis. There is no consensus on the necessity of adjuvant chemotherapy and the selection of surgical procedures for patients with early stage lung cancer. Few studies have investigated the treatment for early stage ASC.

Methods

All cases of TNM stage I ASC as per the seventh edition of the American Joint Committee on Cancer staging system were identified from the Surveillance, Epidemiology, and End Results database from 2004 to 2016. The prognostic factors of the primary cohort were identified. Clinical characteristics, first-line treatments, surgical procedures, and survival data, including overall survival and cancer-specific survival, were analyzed.

Results

A total of 1251 patients were included. The mean age of the patients was 70 years (±9.5 y). Male and white patients accounted for larger proportions. There were 656 and 595 patients with stages IA and IB, respectively. The mean tumor size was 26.2 mm (±10.7 mm). With respect to the treatment, 139 patients who received only chemotherapy had the worst prognosis. Similar outcomes were observed in both the surgery and adjuvant therapy groups. Nevertheless, adjuvant chemotherapy could improve survival outcomes of patients with a tumor size of 4 to 5 cm. Of the 1075 patients who underwent surgery, there were 224 cases of sublobar resection, 834 cases of lobectomy, and 17 cases of extended or sleeve lobectomy. The results revealed that patients who underwent lobectomy had better prognosis.

Conclusions

Early stage ASC has a poor prognosis. Adjuvant chemotherapy was found to have no considerable benefit in patients with stage I disease (eighth edition). Lobectomy or other radical surgeries are recommended as they can improve overall survival of patients with ASC.

[Clinical Characteristics and Prognostic Factors of Lung Adenosquamous Carcinoma in SEER Database between 2010 and 2015]

背景与目的

肺癌发病率和死亡率均位居所有恶性肿瘤的第一，严重影响人类健康。非小细胞肺癌（non-small cell lung cancer, NSCLC）中常见病理类型为腺癌和鳞癌，临床研究和关注较多，而肺腺鳞癌是一种较为罕见的肺癌病理类型，其临床特征及预后相关因素尚未完全明确。本研究即对肺腺鳞癌的临床特征及预后进行分析，并构建了列线图来预测患者的预后。

方法

我们纳入了2010年-2015年美国SEER（Surveillance, Epidemiology, and End Results）数据库中的肺腺鳞癌数据，与同期的肺腺癌和肺鳞癌的临床特征和预后进行了比较。随后我们采用单因素和多因素分析研究了肺腺鳞癌患者预后的独立相关因素，以此构建了列线图并进行了验证。

结果

我们一共入组了肺腺鳞癌患者1, 453例。与同期的肺腺癌和肺鳞癌患者相比较，肺腺鳞癌患者在大多数变量中的分布情况均介于肺腺癌和鳞癌之间，其预后也优于肺鳞癌但差于肺腺癌患者。多因素分析发现，年龄、分化程度、肿瘤-淋巴结-转移（tumor-node-metastasis, TNM）、手术和化疗是患者预后的独立影响因素（P均 < 0.001）。我们以此构建了列线图，其C-index为0.783（0.767-0.799），区分度检验和一致性检验均表明这一列线图可以有效地预测患者预后。

结论

肺腺鳞癌具有独特的临床病理和预后特征。年龄、分化、T、N、M、手术和化疗状况是肺腺鳞癌患者预后的独立预测因素。我们以此构建的列线图可以较好地预测患者预后。

Adenosquamous carcinoma of the lung

Adenosquamous carcinoma of the lung (ASC), a relatively rare subtype of non-small-cell lung cancer, is defined as a malignancy containing components of lung adenocarcinoma (ADC) and lung squamous cell carcinoma (SCC). Although ASC has biological characteristics of ADC and SCC, it is not by any means a simple hybrid of two components above. It is extremely difficult to diagnose preoperatively; pathology of surgically resected gross specimen is the most effective means for adequate diagnosis of ASC. Platinum-based postoperative adjuvant chemotherapy for at least four cycles can significantly improve the survival in stage III patients with ASC. Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) such as erlotinib and gefitinib can be the effective therapeutic strategies for advanced EGFR-mutant ASC. The studies of crizotinib in the treatment of patients with ASC are very limited. Immune checkpoint blockade therapy may be a potential treatment choice for ASC patients.

Surgical significance and efficacy of epidermal growth factor receptor tyrosine kinase inhibitors in patients with primary lung adenosquamous carcinoma

Background

Primary adenosquamous carcinoma (ASC) of the lung is a rare and aggressive disease. The accurate diagnosis of ASC based on small biopsies is challenging because of the mixed components within the tumor, and this may lead to suboptimal treatment. Furthermore, information about the efficacy of epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) in lung ASC is limited.

Patients and methods

Data on a cohort of patients with lung ASC who underwent surgery between October 2008 and December 2016 at a single institution were retrospectively reviewed.

Results

This study analyzed 148 patients. Differences between the pre- and post-resection diagnosis were observed. Based on the results of preoperative biopsy, patients were diagnosed as having squamous cell carcinoma (n=26), adenocarcinoma (n=20), poorly differentiated carcinoma (n=20), and large cell carcinoma (n=1), and finally diagnosed as having ASC based on histopathological examination of the surgical specimens. Thirty patients (20.3%) with EGFR-sensitizing mutations (TKI group) were treated with EGFR-TKIs after surgery, whereas the remaining patients (79.7%) with unknown EGFR-mutation status received chemotherapy or chemoradiotherapy alone (non-TKI group). TKI treatment was associated with better median overall survival (OS) (HR=0.619; p=0.034). Multivariate analysis identified the presence of EGFR-TKI treatment as an independent prognostic factor for OS (HR=0.471; p=0.003).

Conclusion

Discrepancies between the pre- and post-operative diagnosis reflect the inadequacy of non-resection approaches to the diagnosis of ASC. ASC patients harboring EGFR-sensitizing mutations who were treated with EGFR-TKIs showed a significantly better prognosis than those receiving chemotherapy or chemoradiotherapy alone.

Pulmonary micropapillary-type adenosquamous carcinoma sharing epidermal growth factor receptor mutation in adenocarcinoma and squamous cell carcinoma

Adenosquamous lung carcinoma (AdSqLC) has a worse prognosis than adenocarcinoma (ADC) or squamous cell carcinoma (SQCC). Micropapillary pattern in lung ADC is an additional poor prognostic factor. We describe a rare case of AdSqLC with epidermal growth factor receptor (EGFR) mutation in both the micropapillary‐ADC and SQCC components, showing long‐term response to gefitinib. A 60‐year‐old woman underwent right lower lobectomy for primary lung cancer. Histopathological examination demonstrated adenosquamous carcinoma comprising micropapillary‐ADC and moderately differentiated SQCC. EGFR exon 19 deletions mutation was detected in both the ADC and SQCC components. Gefitinib was administered for multiple metastatic recurrences on bilateral lung, resulting in remarkable shrinkage of visible lesions. The efficacy of gefitinib lasted for 31 months after the induction. AdSqLCs harbouring the EGFR mutation in both the ADC and SQCC components may well benefit from EGFR tyrosine kinase inhibitors, especially when they contain micropapillary‐ADC component that correlates with frequent EGFR mutations.

Clinical outcomes of epidermal growth factor receptor tyrosine kinase inhibitors in recurrent adenosquamous carcinoma of the lung after resection

PURPOSE

The therapeutic efficacy of targeted therapy for adenosquamous carcinoma (ASC) of the lung remains unclear and the role of epidermal growth factor receptor (EGFR) testing in patients with ASC also remains controversial. We aimed to analyze the efficacy of EGFR tyrosine kinase inhibitors (EGFR-TKIs) in ASC.

METHODS

Clinical records of patients with ASC who received treatment with EGFR-TKIs between January 2006 and December 2014 at two institutions were retrospectively reviewed.

RESULTS

A total of 27 EGFR mutation-positive patients with ASC who received TKI therapy were enrolled in this study. EGFR mutations included a deletion in exon 19 in 15 cases and a point mutation at codon 858 (L858R) in exon 21 in 12 cases. Among the 27 ASC patients who received treatment with EGFR-TKIs, nine had a partial response and 11 achieved stable disease, accounting for a disease control rate of 74.1% (20/27). The median postoperative overall survival (OS) of the EGFR-mutant patients who received TKI therapy was 39 months (95% confidence interval [CI]: 25.6-52.4). The median progression-free survival for EGFR mutation-positive patients was 15 months (95% CI: 12.9-17.1), and the median relapse OS was 19 months (95% CI: 0.9-37.1). In addition, the 3- and 5-year postoperative survival rate was 51.9% and 15.3%, respectively.

CONCLUSION

ASC patients harboring EGFR mutations had a good response to TKI therapy. Routine EGFR testing for ASCs was recommended. Further studies on TKI therapy versus chemotherapy alone for EGFR-mutant ASCs are required.

Improved survival associated with a balanced structure between adenomatous and squamous components in patients with adenosquamous carcinoma of the lung

BACKGROUND

Primary adenosquamous carcinoma (ASC) of the lung is rare and its biological behavior has not yet been thoroughly described. The aim of this study was to analyze the clinicopathological characteristics and prognostic factors associated with ASC.

MATERIALS

Clinical records of patients with ASC of the lung who underwent surgery between October 2008 and December 2014 in a single institution were retrospectively reviewed.

RESULTS

A total of 205 patients were identified. Patients with balanced structural components had significantly better prognosis than those with squamous (p = 0.014) or adenomatous (p < 0.001) predominance, and those with N0, N1, and N2 ASC (N0 vs. N1 [ p = 0.031] and N1 vs. N2 [p = 0.037], respectively), or stage I, II and IIIA ASC (stage I vs. II [p = 0.021] and stage II vs. IIIA [p = 0.007], respectively) had significant differences with respect to overall survival (OS). Multivariate analysis identified structural components (p = 0.011), tumor, node and metastasis (TNM) status (p < 0.001), and adjuvant chemotherapy (p = 0.008) as significantly prognostic factors for OS, and structural components (p = 0.030), TNM stage (p < 0.001) and adjuvant chemotherapy (p = 0.005) as the corresponding variables for disease-free survival.

CONCLUSIONS

A balanced structure between adenomatous and squamous components in patients with primary ASC of the lung was associated with better prognosis.

Epidermal Growth Factor Receptor Activating Mutations in Squamous Histology of Lung Cancer Patients of Southern Bulgaria

There is only limited data on the prevalence of epidermal growth factor receptor (EGFR) activating mutations in squamous cell carcinomas and adenosquamous carcinomas of the lung in patients of the Southern Bulgarian region and the efficacy of EGFR tyrosine kinase inhibitors. AIM: Previous reports for Bulgarian population showed high incidence of EGFR mutations in the squamous cell carcinomas, so we set the goal to investigate their frequency in Southern Bulgaria, after precise immunohistochemical verification of lung cancers. MATERIALS AND METHODS: Two hundred and thirty-six lung carcinomas were included in this prospective study. All biopsies were initially analysed with p63, TTF1, Napsin A, CK7, CK34βE12, synaptophysin, CK20 and CDX2. Two hundred and twenty-five non-small cell lung carcinomas were studied with real-time PCR technology to assess the status of the EGFR gene. RESULTS: We detected 132 adenocarcinomas (58.7%), 89 squamous cell carcinomas (39.2%), 4 adenosquamous carcinomas (1.8%), 9 large cell neuroendocrine carcinomas (3.8%) and 2 metastatic colorectal adenocarcinomas (0.8%). Activating mutations in the EGF receptor had 3 out of 89 squamous cell carcinomas (3.37%). We have established mutations in L858R, deletion in exon 19 and rare mutation in S7681. One out of four adenosquamous carcinomas had a point mutation in the L858R (25%). CONCLUSIONS: The frequency of EGFR mutations we found in lung squamous cell carcinomas in a Southern Bulgarian region is lower than that in European countries. Ethnic diversity in the region does not play role of an independent predictive factor in terms of mutation frequency.

Surgical specimen histology revealed inadequacy of conventional transbronchial needle aspiration sample in the diagnosis of adenosquamous lung carcinoma

OBJECTIVE

We retrospectively reviewed the accuracy of conventional transbronchial needle aspiration (cTBNA) in the subtyping of lesions located in or around central airways by comparing the histological diagnosis based on TBNA and surgical specimens.

MATERIALS AND METHODS

cTBNA was conducted in consecutive patients with lesions located in or around the central airways (trachea, left and right primary bronchi, hilar and mediastinal masses or lymph nodes) between October 2012 and May 2014 in Wuhan No. 1 Hospital. The aspirated specimens in all patients were performed cytological and/or histopathological examination. Of these patients, some were subjected to surgical resection and histopathological examination was performed by the Department of Pathology. In the patients with gross specimens, the final diagnosis was established based on histopathological results from these specimens.

RESULTS

In 63 patients diagnosed with cTBNA for the lesions located in or around the central airways, 23 patients with a diagnosis of lung cancer or atypical hyperplasia underwent surgery. The final diagnosis based on histopathology of surgery specimen was lung cancer in 22 patients [3 small cell lung cancer (SCLC), 9 squamous cell carcinoma (SCC), 5 adenocarcinoma (ADC), 4 adenosquamous carcinoma (ADS) and 1 neuroendocrine carcinoma], and inflammatory pseudotumor in 1 patient. The overall diagnostic yield of cTBNA for lung cancer was 95.7% (22/23), but the accuracy for histological typing of lung cancer is only 63.6% (14/22), for adenosquamous lung carcinoma was only 25% (1/4).

CONCLUSIONS

cTBNA is a safe and effective procedure that can be used for the diagnosis of central lung cancer. However, the accuracy of TBNA for the histological classification of lung cancer is relatively low, especially for adenosquamous lung carcinoma.

Molecular spectrum of somatic EGFR and KRAS gene mutations in non small cell lung carcinoma: determination of frequency, distribution pattern and identification of novel variations in Indian patients

Somatic mutations of EGFR and KRAS gene represent the most common alterations currently known in NSCLC patients. This study explored the frequency, distribution pattern of EGFR and KRAS mutations in Indian patients. The frequencies of EGFR and KRAS mutations were 29 % (116/400) and 4.5 % (6/132) respectively. Both EGFR and KRAS mutations were prevalent in females, and a trend towards higher mutation frequency was seen in patients under ≥ 60 years age. The presence of EGFR and KRAS mutations were higher in adenocarcinomas in comparison to other histological subtype. Sequencing analysis of EGFR exon 18 revealed Inframe deletion (G709_T710 > A) and missense mutation (K713R). Among exon 19 positive cases, 49.3 % (37/75) were in-frame deletions, of which E746_A750del was frequent. Similarly, ~47 % (35/75) cases showed complex mutation involving indel. Among mutations in exon 20 (N = 9), 8 were substitutions, one showed duplication, while all exon 21 mutations were of the missense types with L858R as the most recurrent type. Sequencing analysis of KRAS exon 1 revealed three different types codon 12 substitutions resulting in c34G > T (G12C) (n = 4), c.35G > A (G12D) (n = 1), and c.35G > T (G12V) (n = 1). In conclusion, the present study is an example of molecular diversity of EGFR and KRAS gene in Indian patients and further confirms that the frequency of EGFR and KRAS mutations varies considerably globally. To the best of our knowledge, this is the first Indian study to evaluate KRAS mutation. The current study also served to identify novel variations that added new insights into the genetic heterogeneity of NSCLC.

Clinical Significance of Detecting Somatic Gene Mutations in Surgically Resected Adenosquamous Cell Carcinoma of the Lung in Japanese Patients

BACKGROUND

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) and echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK) inhibitors are effective and useful agents for treating patients who harbor EGFR-TKI-sensitive mutations or EML4-ALK rearrangement. Therefore, the importance of determining the presence of these somatic mutations when treating lung adenocarcinomas is widely accepted. However, genetic mutations are rarely evaluated in patients with adenosquamous cell carcinoma of the lung, a relatively infrequent histologic type of lung cancer, because of limited knowledge and the unclear value of assessing these oncogenic mutations in these patients. Therefore, we investigated the clinical implications of somatic mutations in surgically resected adenosquamous cell carcinoma of the lung in Japanese patients.

METHODS

We retrospectively analyzed 32 patients with adenosquamous cell carcinoma of the lung who underwent surgical resection at two institutes in Japan. EGFR mutations and EML4-ALK rearrangement were assessed in all of the patients.

RESULTS

Overall, 7 (21.9 %) of 32 patients had EGFR mutations: three patients had an exon 19 deletion and 4 had an exon 21, L858R mutation. There were no T790 M mutations. The median relapse-free survival was 766 days and the median overall survival was 1,152 days in the total cohort. Relapse-free survival and overall survival were not significantly different between patients with or without EGFR mutations.

CONCLUSIONS

Detecting EGFR mutations in patients with adenosquamous cell carcinoma is clinically important, especially in patients with disease recurrence because EGFR-TKIs may be effective in this histologic type of lung cancer.

Biomarker expression and druggable gene alterations for development of an appropriate therapeutic protocol for pulmonary adenosquamous carcinoma

AIMS

Pulmonary adenosquamous carcinoma (ASC) is more aggressive than adenocarcinoma (AC) and squamous cell carcinoma (SCC). The genetic features and biomarkers of ASC are not well known. Here, we attempted to identify potential therapeutic markers for ASC.

METHODS AND RESULTS

Surgically resected ASC samples from 65 patients were analysed. We examined the expression of β III-tubulin, thymidylate synthase, breast cancer susceptibility gene 1 and ribonucleotide reductase M1 (RRM1); identified mutations in epidermal growth factor receptor (EGFR), KRAS, BRAF and HER2; and detected ALK, ROS1 and RET rearrangements. Gene amplification and expression of EGFR, human epidermal growth factor receptor 2 (HER2), fibroblast growth factor receptor-1 and MET were also examined. β III-Tubulin showed the highest expression (P = 0.002), and its expression was more frequent in the AC than in the SCC component (P = 0.013). RRM1 expression was more frequent in the SCC component (P = 0.046). EGFR and KRAS mutations were detected in both components (21.5 and 10.9%, respectively). ALK and ROS1 rearrangements and MET amplification were detected in both components in one (1.5%) case.

CONCLUSIONS

In ASC, drug response-specific gene alterations could occur in both AC and SCC components, suggesting that patients with confirmed or suspected ASC should undergo further testing for driver gene analyses.