Do patients with adenosquamous carcinoma of the lung need a more aggressive approach?

Clonal dynamics and Stereo-seq resolve origin and phenotypic plasticity of adenosquamous carcinoma

The genomic origin and development of the biphasic lung adenosquamous carcinoma (ASC) remain inconclusive. Here, we derived potential evolutionary trajectory of ASC through whole-exome sequencing, Stereo-seq, and patient-derived xenografts. We showed that EGFR and MET activating mutations were the main drivers in ASCs. Phylogenetically, these drivers and passenger mutations found in both components were trunk clonal events, confirming monoclonal origination. Comparison of multiple lesions also revealed closer genomic distance between lymph node metastases and the ASC component with the same phenotype. However, as mutational signatures of EGFR-positive lung squamous carcinomas (LUSCs) were more comparable to EGFR-positive ASCs than to wild-type LUSCs, we postulated different origination of these LUSCs, with ASC being the potential intermediate state of driver-positive LUSCs. Spatial transcriptomic profiling inferred transformation from adenocarcinoma to squamous cell carcinoma, which was then histologically captured in vivo. Together, our results explained the development of ASC and provided insights into future clinical decisions.

Clinical significance of visceral pleural and lymphovascular invasion in surgically resected adenosquamous lung cancer

OBJECTIVES

The aim of this study was to assess the relationship between visceral pleural invasion (VPI), lymphovascular invasion (LVI) and other clinicopathological characteristics and their prognostic impact on surgically resected adenosquamous carcinoma (ASC).

METHODS

We retrospectively reviewed 256 patients with radically resected ASC between January 2010 and December 2015. Patients were divided into 2 groups: those with VPI and those with LVI. The effects of VPI and LVI on disease-free survival and overall survival were evaluated, further stratified by tumour size and lymph node status.

RESULTS

Finally, 213 patients with ASC were enrolled in our study. VPI was correlated with tumour location (P < 0.001), pT stage (P < 0.001) and pN stage (P = 0.012). LVI was related to age (P = 0.005) and pN stage (P = 0.003). Both VPI and LVI were adverse prognostic factors for disease-free survival (P = 0.008, P = 0.028) and overall survival (P = 0.005, P = 0.009) using the Kaplan-Meier method. In multivariable analysis only, VPI was an independent risk factor for disease-free survival [hazard ratio (HR) 0.61, 95% confidence interval (CI) 0.42-0.87; false discovery rate, adjusted P = 0.020] and overall survival (HR 0.60, 95% CI 0.42-0.86; false discovery rate, adjusted P = 0.017). When the prognostic value of VPI was stratified by tumour size and lymph node status, we observed that only patients with VPI in tumours ≤4 cm and patients with N0 status had a worse prognosis than those without visceral invasion (P < 0.05).

CONCLUSIONS

VPI and LVI were poor prognostic factors in patients with ASC, but only VPI was an independent factor for survival, especially in patients with tumours ≤4 cm and pN0 status.

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.

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.

Methodological comparison of the allele refractory mutation system and direct sequencing for detecting EGFR mutations in NSCLC, and the association of EGFR mutations with patient characteristics

Gefitinib is effective for patients with non-small cell lung cancer (NSCLC) with a mutation in the epidermal growth factor receptor (EGFR) gene, which makes the detection of EGFR mutations a critical step prior to determining a treatment schedule. Therefore, the present study determined the EGFR mutation status in patients with NSCLC using an allele refractory mutation system (ARMS) and analyzed the detection ratio for different specimen types. A total of 1,596 NSCLS samples were collected and EGFR gene mutations were detected on exons 18-21 using ARMS and direct sequencing. The concordance of two methods reached 89.21%, with a total mutation rate of 45.55% (727/1,596), in which the mutation rate in lung adenocarcinoma samples was markedly increased compared with squamous cell carcinoma (51.77 vs. 8.68%). In patients with lung adenocarcinoma, EGFR mutations were more frequent in female patients than male patients (65.53 vs. 39.80%, P<0.01); there was no observable difference depending on age. Similar results were obtained for squamous cell carcinoma. In the present study, certain rare mutations were also identified; these may be subjects for further study. The impact of different sample types on the consistency between the methods was determined to be insignificant. ARMS is a more applicable approach for large-scale clinical detection than direct sequencing, and we hypothesize that ARMS may replace direct sequencing if the drawbacks of ARMS, including its narrow detection range, can be amended.

Characteristics of lymph node metastasis in resected adenosquamous lung cancer

The aim of this study was to retrospectively analyze the clinical data of resected adenosquamous lung cancer (ASLC) and to explore the influencing factors and clinicopathological characteristics of the metastasis lymph nodes. A total of 1156 consecutive patients with surgically resected lung cancer from January 2009 to June 2014 were studied. Fifty-four previously diagnosed ASLC patients were re-evaluated by experienced pathologists. IHC and H&E staining were employed to examine the primary focus and metastasis lymph nodes. The relationship between lymph node metastasis and clinicopathological characteristics of ASLC patients was then analyzed and the pathological type of metastasis lymph node was also determined. Forty-nine cases of typical ASLC were included in the study. Of the 49 ASLC patients, 26 cases presented lymph node metastasis. Lymph node metastasis was not associated with gender, smoking, tumor distribution, histological type of primary focus, and preoperative CEA level, but was associated with age ≥ 65 (P < .05) and tumor size ≥ 3 cm (P < .05). Lymph node metastasis adenocarcinoma was the main type in ASLC patients, and was related to the age and tumor size of the primary focus. Further large sample studies are necessary to identify influencing factors and clinicopathological characteristics of metastasis lymph nodes.

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.

Successful pemetrexed-containing chemotherapy for epidermal growth factor receptor mutation-positive adenosquamous cell carcinoma of the lung: A case report

Pemetrexed-containing chemotherapy has shown promise in the treatment of non-small-cell lung cancer (NSCLC). However, although adenosquamous cell lung cancer (ASCLC) is a type of NSCLC, the availability of studies investigating its response to pemetrexed-containing chemotherapy is limited. A 66-year-old woman was referred to Mito Medical Center, University of Tsukuba with hemoptysis and a chest computed tomography (CT) scan revealed a large cavitary mass in the lower lobe of the left lung. The patient underwent left lower lobectomy and mediastinal lymph node dissection. The tumor was staged as pT2bN2M0. An epidermal growth factor receptor (EGFR) exon 19 deletion was identified in the adenocarcinomatous as well as the squamous cell carcinomatous components. Despite gefitinib therapy for pulmonary metastases, the patient developed cavitary metastases in both lungs. Therefore, treatment with pemetrexed-containing chemotherapy was initiated. A chest CT scan revealed significant regression of the metastatic lesions in both lungs, with thinning of the walls. The patient remains well and recurrence-free 19 months after the initiation of pemetrexed-containing chemotherapy. Therefore, the clinical response of EGFR mutation-positive ASCLC to pemetrexed-containing chemotherapy was promising, suggesting pemetrexed to be one of the key drugs for this subset of ASCLC patients.

Adenosquamous carcinoma of the lung: surgical management, pathologic characteristics, and prognostic implications

BACKGROUND

Adenosquamous carcinoma (ASC) is a mixed glandular and squamous cell carcinoma with a more aggressive behavior than the other histologic subtypes of lung cancer. We revisited the pathologic characteristics and surgical results associated with ASC.

METHODS

Patients who underwent surgical resection of non-small cell lung cancer in two French centers were retrospectively reviewed. Patients presenting with ASC (n=141) were compared to those with adenocarcinomas (AC, n=2415) and squamous cell carcinomas (SCC, n=2662) regarding preoperative data, histologic characteristics, and outcome.

RESULTS

The frequency of ASC and SCC decreased over time. ASC patients were similar to AC patients regarding age, sex, and smoking habits. The type of resections performed in ASC patients was intermediary between SCC (more pneumonectomy) and AC (more lobectomy) patients. ASC was associated with larger size, more frequent visceral pleura invasion, microinvasion of the lymphatic vessels, and ipsilateral second nodules, compared with SCC and AC. Among the 135 patients with documented ASC, 48% presented with a combination of AC and SCC tumor cells ranging between 40% and 60% of each component, and 55% of cases were associated with undifferentiated large cells. ASC was associated with a lower 5-year survival rate (37%) than SCC and AC (43.4% and 42.8%, respectively, p=0.017). For ASC patients, survival was better during the last decade or in cases of balanced AC/SCC components.

CONCLUSIONS

ASC is characterized by both histologic aggressiveness and adverse prognosis. In this setting, the impact of adjuvant therapies needs to be reevaluated.

[Mixed lung tumors: pathological update]

The pathological diagnosis of lung cancer is based on the WHO classification 2004. Tumors containing several tumoral contingents are rare but put at the same time problems of diagnosis and therapeutic coverage. On biopsy, the diagnosis can be refined by using immuno-histochemistry and the recent multidisciplinary classification IALSC/ARS/ETS. Some of these tumors can present molecular anomalies and therefore are accessible to targeted therapies: the precision of the pathological diagnosis is thus essential.

EGFR and KRAS mutations in Chinese patients with adenosquamous carcinoma of the lung

Adenosquamous carcinoma (ADSQ) is uncommon in non-small cell lung cancer (NSCLC). The frequency rate of ADSQ was 9.7% of 6990 primary lung cancers resected in our department. Many researches have analyzed genetic and molecular alterations in adenocarcinoma (AD) and squamous cell carcinoma (SQ), but few molecular studies have been conducted on heterogeneous ADSQ. The current study was to investigate gene mutations of epidermal growth factor receptor (EGFR) and Kirsten rat sarcoma viral oncogene (KRAS) and their correlation with clinical variables in Chinese patients with ADSQ. Histologic features were reviewed, and immunohistochemical (IHC) and molecular (EGFR and KRAS) studies were done in 55 Chinese patients with ADSQ. Microscopically, all the tumors demonstrated dual differentiation with varying proportions of AD and SQ. Based on morphological diagnosis, a combination of multiple IHC markers is helpful for accurately discriminating two undifferentiated histologic subtypes of ADSQ. EGFR mutations were identified in 21 (38.2%) patients: 11 mutations were in exon 19, 1 in exon 20, 7 in exon 21 and double mutations were found in two patients. We also found two new mutations, namely, L747-E749del K754A within exon 19 and H850R within exon 21. Moreover, 16 (29.1%) silent mutations Q787Q in exon 20 were found in the series, five of which coexisted with other mutations. EGFR mutations were more frequently found in patients with size of the tumors ≥3cm [19/35 (54.3%); 2/20 (10%); P=0.001] or coexistent double cancer. However, the EGFR mutation was not associated with gender, age, lymph node status, tumor stage and smoking history. KRAS mutations were present in 2 (3.64%) male patients in codon12 (G12C) and none of them showed EGFR mutation. Moreover, identical EGFR and KRAS mutations in both components of ADSQ were further confirmed by microdissection techniques. The data indicated that the incidence of EGFR and KRAS mutations in Chinese patients with ADSQ were similar to those of Asian patients with AD. Furthermore, EGFR silent mutations accounted for a large proportion in ADSQ. Additional prospective studies are needed in order to define the clinical relevance of new and silent mutation variants.

Adenosquamous lung carcinomas: a histologic subtype with poor prognosis

INTRODUCTION

The aim of this study is to evaluate the prognostic factors and outcome of patients operated for adenosquamous (ADS) carcinoma of the lung, in comparison with adenocarcinoma (AD) and squamous cell carcinoma (SCC).

METHODS

a retrospective review of our thoracic cancer surgical database for patients operated for ADS, SCC and AD between January, 1995 and December, 2009 was done.

RESULTS

Forty-eight patients (39 males, 81.3%) had ADS; complete tumor resection and lymphadenectomy was accomplished in all patients. A higher stage at presentation was observed in ADS, as compared to AD or SCC (p=0.0001). Three and 5-year survival rates were 25% and 15%. ADS overall survival was worse than AD or SCC (p=0.0005). Three and 5-year survival rates of ADS Stage I were similar to those of Stage IIIA AD or SCC. More than half ADS patients developed distant metastases (MTS) or local recurrences. Brain MTS were the most frequent. Median survival for those patients was 8±2.3 months. Postoperative platinum-based chemotherapy statistically improved patients survival (p=0.02). In the multivariate analysis, the presence of MTS (p=0.001), the tumor perineural invasion (p=0.01) and the tumor stage (p=0.0005) were factors associated with poor prognosis. Adjuvant chemotherapy was a significant positive prognostic factor (p=0.00001).

CONCLUSIONS

ADS are uncommon and extremely aggressive lung tumors. Adjuvant chemotherapy should be administered even in Stage I radically resected tumors. A whole brain postoperative prophylactic radiotherapy could be proposed to reduce risk of developing brain MTS.

Identical epidermal growth factor receptor mutations in adenocarcinomatous and squamous cell carcinomatous components of adenosquamous carcinoma of the lung

BACKGROUND

Adenosquamous carcinoma of the lung is composed of adenocarcinomatous and squamous cell carcinomatous components. The epidermal growth factor receptor (EGFR) mutations occur mostly in adenocarcinomas and rarely in squamous cell carcinoma of lung. Attempts to investigate the EGFR mutation status in each component of adenosquamous carcinoma and to characterize the patients according to mutation status may help to understand the histogenesis of adenosquamous carcinoma.

METHODS

The mutation status of EGFR kinase domain from exon 18 to 21 was investigated in 25 Korean patients with adenosquamous carcinoma by polymerase chain reaction-single strand conformation polymorphism using the tissues of each component from the adenosquamous carcinoma tumor. Clinicopathologic characteristics of the patients according to the status of EGFR mutations were compared.

RESULTS

EGFR mutations were identified in 11 (44%) patients: 9 mutations were in exon 19, 1 in exon 20, and 1 in exon 21. EGFR mutations were significantly more frequent (P = .005) in women (n = 8, 80%) than men (n = 3, 20%). Never-smokers (n = 8, 62%) had EGFR mutations more commonly than smokers (n = 3, 25%; P = .111). Identical EGFR mutations in both components of adenosquamous carcinoma were confirmed by nucleotide sequencing.

CONCLUSIONS

The frequency of EGFR mutation and clinicopathologic characteristics of the EGFR mutants in adenosquamous carcinoma are similar to those of Asian patients with adenocarcinomas. Identical EGFR mutations in both components suggest the possibility of monoclonality in the histogenesis of adenosquamous carcinoma.

Adenosquamous carcinoma of the lung: CT—pathological correlation

AIM

To correlate CT morphological features and histopathological findings of adenosquamous carcinoma of the lung.

MATERIALS AND METHODS

In all, 29 patients underwent contrast-enhanced CT of an adenosquamous carcinoma of the lung, followed by resection of the cancer. Correlations between CT morphological and histopathological features were evaluated, including location, characteristics of margins, attenuation and the presence of necrosis.

RESULTS

The tumour was peripheral in 21 (72%) and central in 8 (28%) cases. The tumours varied in size from 1.1cm to 11.0cm (mean 3.8cm); 20 (69%) appeared as heterogeneous masses and 9 (31%) as homogeneous masses. The most common CT features were lobulation in 27 (93%), pleural tail in 22 (76%), spiculation in 17 (59%), necrosis in 15 (52%) and vessel convergence in 13 (45%). Among the 21 peripheral tumours, 14 (67%) showed intratumoural necrosis and 17 (81%) were heterogeneous. Among the 8 central tumours, only 1 (12.5%) showed intratumoural necrosis and 5 (62.5%) were homogeneous. These CT features corresponded mainly to solid tumour growth, which was composed of both squamous cell carcinomatous and adenocarcinomatous tissue.

CONCLUSION

Adenosquamous carcinoma of the lung is shown to be characteristically a solid, lobulated nodule or mass, more commonly peripheral than central. After intravenous injection of positive contrast medium, CT shows that the peripheral lesions are usually of heterogeneous soft-tissue attenuation.

Surgical treatment of other bronchial tumors

Bronchial gland tumors (bronchial carcinoids, adenoid cystic carcinoma, mucoepidermoid carcinoma are the most common), benign tumors and other rare primary malignant neoplasms present as endobronchial tumors. This article discusses the surgical treatment of each of these tumors individually.