Histological diversity in basaloid squamous cell carcinoma of the esophagus

Atypical intrapapillary capillary loops in early-stage basaloid squamous cell carcinoma of the esophagus

Basaloid squamous cell carcinoma of the esophagus (BSCCE) is rare and extremely difficult to identify at early stage.We herein presented a superficial depressed lesion at early stage.

A comparative analysis of clinicopathological factors and survival between esophageal basaloid squamous cell carcinoma and conventional esophageal squamous cell carcinoma

INTRODUCTION

Recently, the number of diagnosed esophageal basaloid squamous cell carcinoma (EBSCC) has gradually increased. However, available data on EBSCC are limited to date.

METHODS

A total of 165 EBSCC (Cohort 1) and 515 conventional esophageal squamous cell carcinoma (ESCC) (Cohort 2) were retrospectively analyzed.

RESULTS

In Cohort 1, 70 cases only had invasive EBSCC component (42.4%, defined as Group 1), 73 cases had concomitant invasive ESCC component (44.2%, Group 2), and 22 had concomitant invasive poor-differentiated component (13.3%, Group 3). Lymph node metastasis rates of Group 3, Group 2 and Group 1 were ranked from high to low (P = 0.044). There were higher patient age (P = 0.047), smaller tumor size (P = 0.009), more nerve invasion (P < 0.001), and lower pTNM stage (P < 0.001) in EBSCC (Cohort 1), compared with ESCC (Cohort 2). In Cohort 1 and Cohort 2, pTNM stage was an independent prognostic factor for both DFS and OS. No significant survival difference was found between EBSCC (Cohort 1) and ESCC (Cohort 2) in pIA-B stage, pIIA-B stage, pIIIA-B stage and pIVA-B stage (P > 0.05).

CONCLUSION

Our analysis of the largest EBSCC series from a single institution to date with conventional ESCC demonstrated that EBSCC carried a similar prognosis with ESCC in pIA-B stage, pIIA-B stage, pIIIA-B stage and pIVA-B stage. And pure EBSCC, didn't have poorer survival than mixed EBSCC with concomitant ESCC or other components. Our findings may be valuable in the better understanding of EBSCC's biological behaviors, and the related molecular mechanism is needed to be explored in the future.

Comparative Analysis of Clinicopathological Characteristics, Survival Features, and Protein Expression Between Basaloid and Squamous Cell Carcinoma of the Esophagus

Background

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma (SCC) of the esophagus. This study aimed to assess the discrepancy in clinicopathological characteristics and protein expression between esophageal BSCC and typical esophageal SCC.

Study Design

We reviewed 40 cases of esophageal BSCC. As controls, 63 well-differentiated SCC (WSCC) patients, 70 moderately differentiated SCC (MSCC) patients, and 51 poorly differentiated SCC (PSCC) patients were selected. The clinicopathologic characteristics and immunoreactivity of Ki-67, p53, p63, and epidermal growth factor receptor (EGFR) were then evaluated in the BSCC and typical SCC patients.

Results

The 5-year survival rates for the BSCC patients were 27.5%. The prognostic outcomes of the BSCC group were similar to those of the PSCC and MSCC groups but worse than that of the WSCC group, with a significant difference (P=0.045). Ki-67 expression was significantly higher in the BSCC group than that in the WSCC group (P < 0.05). Meanwhile, there were no significant differences in the expression of the other molecular markers (p53, p63, and EGFR) between the typical SCC and BSCC groups (P > 0.05). The median survival time of esophageal the BSCC patients with low p53 expression was significantly longer than that of the patients with high p53 expression (P=0.026). Further, the median survival time of the esophageal BSCC patients with high p63 expression was significantly longer than that of the patients with low p63 expression (P=0.041). Meanwhile, Ki-67 and EGFR expressions were not correlated with OS in the BSCC group.

Conclusion

Esophageal BSCC has a more clinically virulent course. Notably, p53 and p63 expression are associated with prognosis in BSCC. These findings conject that evaluation of multiple cancer biomarkers might be a promising auxiliary diagnostic indicator in BSCC.

Esophageal basaloid squamous cell carcinoma presenting as a subepithelial lesion

Basaloid squamous cell carcinoma of the esophagus is rare and generally detected at advanced stage, and its prognosis is poorer than that of conventional esophageal squamous cell carcinoma. Therefore, detection at the early stage is crucial for patient survival. We experienced an elevated esophageal basaloid squamous cell carcinoma presenting as a subepithelial tumor-like lesion. Although the lesion needed to be differentiated from subepithelial tumor, we diagnosed it as early stage and treated with endoscopic submucosal dissection. We report the macroscopic and microscopic findings of basaloid carcinoma through this case along with a review of the relevant literature.

Beyond Squamous Cell Carcinoma: Basaloid Squamous Cell Carcinoma of the Esophagus

Basaloid squamous cell carcinoma (BSCC) is a poorly differentiated variant of squamous cell carcinoma (SCC) with distinct morphologic characteristics. Yet, there are no clearly defined guidelines established for management. BSCC in the esophagus is a very rare entity, with the proportion of esophageal BSCC ranging from 0.068% to 11%. This wide range is thought to be secondary to difficulty making the diagnosis on small biopsy specimens and the lack of a universally defined proportion of BSCC components necessary to make the diagnosis. We present the case of a 57-year-old African American female, who underwent esophagogastroduodenoscopy (EGD) after an abnormal barium swallow in the setting of two months history of dysphagia and weight loss and was diagnosed with BSCC of the esophagus on histopathology.

Basaloid squamous cell carcinoma with adenoid cystic-like features of the head and neck region: A report of two cases

The histology of basaloid squamous cell carcinoma (BSCC) can resemble that of adenoid cystic carcinoma (AdCC). Herein, we report two cases of BSCC with adenoid cystic-like features (BSCC-AdC). We collected cases of AdCC and BSCC of the head and neck region, extracted two cases with unusual histology, and reexamined them histologically and immunohistochemically. Case 1 involved an 81-year-old Japanese male, who had an elastic-hard mass on the left side of his tongue, and a biopsy examination suggested AdCC. Case 2 involved a 63-year-old Japanese male, who had a polypoid mass on his right hypopharynx. He was diagnosed with AdCC with high-grade transformation. Histologically, atypical cells in a myxoid stroma, which exhibited trabecular, nest-like, and/or cribriform growth patterns, and necrosis were observed in both cases. Case 2 displayed more marked cellular atypia than Case 1. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin 5/6, p63/p40, SRY-related HMG-box 10 and Ki-67, but negative for other myoepithelial markers and p16. Finally, both cases were rediagnosed as BSCC-AdC. It is known that esophageal BSCC displays adenoid cystic-like features, and BSCC-AdC also sometimes occurs in the head and neck region. Clinicians should carefully differentiate BSCC-AdC from AdCC of the minor salivary glands and human papillomavirus-related carcinoma.

Submucosal gland neoplasms of the esophagus: an update and review

Submucosal glands (SMGs) present throughout human esophagus with clusters at either the upper third or lower third of the organ. SMGs tend to atrophy with age, and neoplasms arising in these glands are rare. In order to bring convenience to diagnosis, we summarize the histopathologic characteristics of all esophageal submucosal gland tumors (SGTs). Due to the morphological similarity, the nomenclature of salivary tumors is adopted for SGTs. However, there is great confusion about the definition and histogenesis of these tumors, especially the malignant subtypes. In the literature, esophageal mucoepidermoid carcinoma and adenoid cystic carcinoma usually adjoin the surface squamous epithelium and coexist with intraepithelial neoplasia or invasive squamous cell carcinoma (SCC). In addition, the typical gene alterations of salivary tumors have not been reported in these SGTs. Therefore, we propose to apply stringent diagnostic criteria to esophageal SGTs so as to exclude mimickers that are SCCs with various degree of SMG differentiation.

Clinicopahological features of superficial basaloid squamous cell carcinoma of the esophagus

Basaloid squamous cell carcinoma (BSC) of the esophagus is classified as an epithelial malignant tumor and is a rare variant of squamous cell carcinoma (SCC). Most previous reports have suggested that advanced BSC has a poorer prognosis than typical SCC because of its high biological malignancy, but the biological activity of superficial BSC remains unclear. Twenty cases of superficial BSC, which underwent surgical resection in Tokai University Hospital between January 2004 and December 2013, were analyzed retrospectively. Among these cases, 19 cases with a T1 depth of invasion (BSC group) were compared with 180 cases of SCC that were resected during the same period and were pathologically diagnosed as T1 (SCC group). The frequency of lymph node metastasis in the T1 BSC group was significantly lower (2 patients, 11%) than that in the SCC group (84 patients, 47%) (P = 0.005). The frequency of lymphatic invasion in the BSC group was also lower (9 patients, 47%) than that in the SCC group (131 patients, 73%) (P = 0.021). The pathological type of the metastatic lymph node was BSC in all the superficial BSC cases with lymph node metastasis. This study demonstrated that lymph node metastasis was less likely to occur in cases with superficial BSC than in cases with superficial SCC.

A Case of Basaloid Squamous Cell Carcinoma of Polypoid Type in the Esophagus

Basaloid squamous cell carcinoma of the esophagus is very rare. Further, polypoid type of esophageal cancer is also rare. We have recently treated a case of basaloid squamous cell carcinoma which presented as a 1.3-cm esophageal polyp. A 48-year-old woman was referred to our hospital because of a polypoid mass at 36 cm distance from the upper incisor on endoscopic examination, and the result of the biopsy was basaloid squamous cell carcinoma. The patient underwent Ivor Lewis operation with lymph node dissection. Two basaloid squamous cell carcinomas, of 1.3 and 0.4 cm, were diagnosed in the final pathologic examination. Regular periodic follow-up showed no evidence of recurrence or metastasis in the 5-month postoperative period.

A novel gene expression scoring system for accurate diagnosis of basaloid squamous cell carcinoma of the esophagus

Basaloid squamous cell carcinoma of the esophagus (BSCE) is a rare variant of squamous cell carcinoma that is difficult to distinguish from other carcinomas by preoperative endoscopic biopsy because of its histological varieties. Accurate diagnosis is essential for adequate treatment, and the methods proposed so far (e.g., immunohistochemical staining) have limitations. In this study, we tried to identify the characteristic bundles of gene expression in BSCE using comprehensive gene expression analysis (CGEA). Subsequently, we constructed a gene expression scoring system for the proper diagnosis of BSCE. Fifty-seven surgical specimens, including seven BSCEs, obtained from 30 patients who underwent esophagectomy were used for constructing the scoring system. Three hundred and twelve biopsy specimens, including eight BSCEs, obtained from 80 patients and 20 commercially available formalin-fixed paraffin-embedded (FFPE) specimens diagnosed as esophageal cancer, including 13 BSCEs, were used for validation. After our original mathematical extraction algorithm, 75 genes were extracted to distinguish BSCE from non-BSCE. The cumulative converted values (gene expression score) of the respective 75 genes from each specimen were obtained and lined up in ascending order to assess the optimal gene expression cut-off score for a definitive diagnosis of BSCE. The validation of this scoring system showed high prediction of the biopsy specimens [area under the curve (AUC)=0.981; 95% confidence interval (CI): 0.952‑1.000] and the commercially available FFPE specimens (AUC=0.901; 95% CI: 0.750-1.000). In conclusion, using CGEA in a gene expression scoring system helps in differentiating BSCE from non-BSCE with high accuracy and may contribute in improving BSCE treatment.

Basaloid Squamous Cell Carcinoma of the Head and Neck: Subclassification into Basal, Ductal, and Mixed Subtypes Based on Comparison of Clinico-pathologic Features and Expression of p53, Cyclin D1, Epidermal Growth Factor Receptor, p16, and Human Papillomavirus

Background

Basaloid squamous cell carcinoma (BSCC) is a rare variant of squamous cell carcinoma with distinct pathologic characteristics. The histogenesis of BSCC is not fully understood, and the cancer has been suggested to originate from a totipotent primitive cell in the basal cell layer of the surface epithelium or in the proximal duct of secretory glands.

Methods

Twenty-six cases of head and neck BSCC from Asan Medical Center, Seoul, Korea, reported during a 14-year-period were subclassified into basal, ductal, and mixed subtypes according to the expression of basal (cytokeratin [CK] 5/6, p63) or ductal markers (CK7, CK8/18). The cases were also subject to immunohistochemical study for CK19, p53, cyclin D1, epidermal growth factor receptor (EGFR), and p16 and to in situ hybridization for human papillomavirus (HPV), and the results were clinico-pathologically compared.

Results

Mixed subtype (12 cases) was the most common, and these cases showed hypopharyngeal predilection, older age, and higher expression of CK19, p53, and EGFR than other subtypes. The basal subtype (nine cases) showed frequent comedo-necrosis and high expression of cyclin D1. The ductal subtype (five cases) showed the lowest expression of p53, cyclin D1, and EGFR. A small number of p16- and/or HPV-positive cases were not restricted to one subtype. BSCC was the cause of death in 19 patients, and the average follow-up period for all patients was 79.5 months. Overall survival among the three subtypes was not significantly different.

Conclusions

The results of this study suggest a heterogeneous pathogenesis of head and neck BSCC. Each subtype showed variable histology and immunoprofiles, although the clinical implication of heterogeneity was not determined in this study.

Myrciaria cauliflora extract improves diabetic nephropathy via suppression of oxidative stress and inflammation in streptozotocin-nicotinamide mice

Myrciaria cauliflora is a functional food rich in anthocyanins, possessing antioxidative and anti-inflammatory properties. Our previous results demonstrated M. cauliflora extract (MCE) had beneficial effects in diabetic nephropathy (DN) and via the inhibition of Ras/PI3K/Akt and kidney fibrosis-related proteins. The purpose of this study was to assess the benefit of MCE in diabetes associated with kidney inflammation and glycemic regulation in streptozotocin–nicotinamide (STZ/NA)-induced diabetic mice. Compared with the untreated diabetic group, MCE significantly improved blood glucose and serum biochemical characteristic levels. Exposure to MCE increased antioxidative enzyme activity and diminished reactive oxygen synthesis. Mice receiving MCE supplementation had reduced intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemoattractant protein 1 (MCP-1), colony stimulating factor 1 (CSF-1), interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) levels compared to the untreated diabetic mice. Inflammatory and fibrotic related proteins such as collagen IV, fibronectin, Janus kinase (JAK), phosphorylated signal transducer and activator of transcription 3 (STAT3), protein kinase C beta (PKC-β), and nuclear factor kappa B (NF-κB) were also inhibited by MCE treatment in STZ/NA mice. These results suggest that MCE may be used as a hypoglycemic agent and antioxidant in Type 2 diabetic mice.

Comparative analysis of basaloid and conventional squamous cell carcinomas of the esophagus: prognostic relevance of clinicopathological features and protein expression

Basaloid squamous cell carcinoma (BSCC), a variant of squamous cell carcinoma (SCC), is a rare and aggressive epithelial malignancy which has been reported in only 0.1-11 % of primary esophageal carcinomas. In this study, a comparison of clinicopathological features and protein expression between esophageal BSCC (EBSCC) and conventional esophageal SCC (ESCC) cases from Brazil was performed in order to find factors that can be relevant to better characterize EBSCC. The expression of HER2, epidermal growth factor receptor (EGFR), Ki-67, and cyclins (A, B1, and D1) in 111 cases (95 ESCC and 16 EBSCC) was evaluated by immunohistochemistry using tissue microarray. When the clinicopathological data were compared, no significant difference was found between the two histological types. Although the difference is not significant (p = 0.055), the EGFR expression was more frequent in the conventional ESCC than in the EBSCC group. Our results indicate that the clinicopathological profiles of conventional ESCC and EBSCC are similar and provide no indicators for differences in prognosis between these two groups.

Clinical outcomes of basaloid squamous cell carcinoma of the esophagus: a retrospective analysis of 142 cases

BACKGROUND

Basaloid squamous cell carcinoma of the esophagus (BSCCE) is a rare and distinctive tumor with no standard treatment. This study aimed to explore treatment in relation to prognosis of the disease.

METHODS

A total of 142 patients with BSCCE that underwent treatment in our hospital from March 1999 to July 2010 were retrospectively analyzed. All patients received surgery, 42 postoperative radiotherapy and 28 patients chemotherapy.

RESULTS

There were 26 patients included in stage I, 60 in stage II, 53 in stage III and 3 in stage IV. The clinical symptoms and macroscopic performances of BSCCE did not differ from those of typical esophageal squamous cell carcinoma. Among 118 patients receiving endoscopic biopsy, only 12 were diagnosed with BSCCE. The median survival time (MST) of the entire group was 32 months, with 1-, 3- and 5-year overall survival (OS) of 81.4%, 46.8% and 31.0%, respectively. The 5-year OS of stage I and II patients was significantly longer than that of stages III/IV, at 60.3%, 36.1% and 10.9%, respectively (p<0.001, p=0.001). The MST and 5-year OS were 59.0 months and 47.4% in patients with tumors located in the lower thoracic esophagus, and 27.0 months and 18.1% in those with lesions in the upper/middle esophagus (p=0.002). However, the survival was not significantly improved in patients undegoing adjunctive therapy. Multivariate analysis showed TNM stage and tumor location to be independent prognostic factors. Furthermore, distant metastasis was the most frequent failure pattern, with a median recurrence time of 10 months.

CONCLUSION

BSCCE is an aggressive disease with rapid progression and a propensity for distant metastasis. It is difficult to make a definitive diagnosis via preoperative biopsy. Multidisciplinary therapy including radical esophagectomy with extended lymphadenectomy should be recommended, while the effectiveness of radiochemotherapy requires further validation for BSCCE.

Surgical resection of a solitary pulmonary metastasis from basaloid squamous cell carcinoma of the esophagus: a case report

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a relatively rare variant of esophageal malignancies. It is regarded as a disease with a poor prognosis because of the high frequency of distant metastases. We managed a case of resected solitary pulmonary metastasis of BSCC of the esophagus in a 78-year-old female. We performed curative thoracic esophagectomy with three-field lymph node dissection for her disease. After two years and nine months, a thoracoscopic partial resection of the left lung was performed for the solitary pulmonary metastasis. At present, one year after the surgery, the patient is doing well without any recurrence. There have been few reports of case of resected pulmonary metastases. In addition, no treatment strategy for pulmonary metastases from BSCC of the esophagus has been established because of the limited number of cases. Additional cases are required to determine the treatment method.

Basaloid squamous cell carcinoma of the esophagus

PURPOSE

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare carcinoma with distinct characteristics. No standard treatment has been established. This retrospective study was designed to investigate the clinical and pathological characteristics, diagnosis, treatment, and prognosis of esophageal BSCC.

METHODS

Clinical data were retrospectively analyzed from 26 patients with pathologically confirmed esophageal BSCC who underwent transthoracic esophagectomy with lymphadenectomy between January 1995 and June 2010 at the Cancer Hospital of Shantou University Medical College. Clinicopathologic data between BSCC patients and different histologic grades of esophageal squamous cell carcinoma (ESCC) patients were statistically compared by means of the χ(2) test or Fisher's exact test. The Kaplan-Meier and log-rank methods were used to estimate and compare survival rates.

RESULTS

Microscopically, BSCC was characterized by a nesting, lobular, or trabecular arrangement of small crowded cells with scant cytoplasm. None of the histologic specimens taken at preoperative esophagoscopy were diagnosed as BSCC. The median survival time (MST) of the 26 patients was 29.0 months (95% confidence interval, 9.0-49.0), and the 1-, 3-, and 5-year overall survival rates were 73.1, 42.7, and 36.6%, respectively. The MST for BSCC patients was significantly lower than that of well-differentiated SCC patients (P = 0.024), but there were no significant differences between the MST for BSCC patients and that of moderately or poorly differentiated SCC patients (P > 0.05).

CONCLUSIONS

BSCC of the esophagus is a rare but distinctive disease and is prone to be misdiagnosed by endoscopic biopsy. The prognosis is poorer than well-differentiated SCC, but similar to moderately or poorly differentiated SCC.

Review: Experimental models for Barrett's esophagus and esophageal adenocarcinoma

Several different cell culture systems and laboratory animal models have been used over the years to study Barrett's esophagus (BE) and esophageal adenocarcinoma (EAC). Most of the existing models have key differences with the human esophagus and complex pathogenesis of disease. None of the models offers an ideal system for the complex study of environmental exposure, genetic risk, and prevention strategies. In fact, different model systems may be required to answer different specific research questions about the pathogenesis of BE and EAC. Given the high mortality associated with EAC and the fact that current screening strategies miss most cases of EAC, advances in basic and translational science related to esophageal injury, repair, and carcinogenesis are clearly needed. This review describes several of the existing and potential model systems for BE and EAC with their benefits and disadvantages.

A case of long-term survival after pulmonary resection for metachronous pulmonary metastasis of basaloid squamous cell carcinoma of the esophagus

INTRODUCTION

Basaloid squamous cell carcinoma of the esophagus (BSCE) is a rare malignancy among esophageal cancers. We reported a case of 63-year-old woman with metachronous pulmonary metastasis of BSCE, successfully treated by metastasectomy of the left lung.

PRESENTATION OF CASE

Biopsy specimens of upper gastrointestinal fiberscopy led to diagnosis of poorly differentiated squamous cell carcinoma of the esophagus. Computed tomography revealed metastatic lymph nodes surrounding the bilateral recurrent laryngeal nerve and no evidence of metastasis to distant organs. Curative esophagectomy with three-field lymph node dissection was performed through thoracoscopic approach. Pathological examination of the resected specimens led to diagnosis of BSCE with invasion into the submucosal layer of the esophageal wall. Two years later, a solitary oval-shaped pulmonary lesion of approximately 10mm was detected in the left lung. Wedge resection of the left upper lobe was performed via thoracoscopic approach. The postoperative course was uneventful. Histologically, the pulmonary lesion was diagnosed as metastatic BSCE. Follow-up indicated no recurrence 9 years after the initial surgery.

DISCUSSION

Surgical intervention was acceptable on this case of solitary pulmonary metastasis. However, data are lacking about the efficacy of pulmonary resection for metachronous pulmonary metastasis of BSCE because the postoperative outcome is usually poor. The efficacy of surgical intervention for metastatic lesions of BSCE is debatable and requires further examination.

CONCLUSION

Although the usefulness of surgical intervention for metastatic lesions from BSCE is controversial, the patients with metachronous solitary metastasis to the lung and without extrapulmonary metastasis would be good candidate for pulmonary resection.

Immunohistochemical and oncogenetic analyses of the esophageal basaloid squamous cell carcinoma in comparison with conventional squamous cell carcinomas

Basaloid squamous cell carcinoma of the esophagus is a rare variant of squamous cell carcinoma. We reviewed 878 cases of esophageal squamous cell carcinoma and detected 22 cases (3%) of basaloid squamous cell carcinoma. These tumors and stage-matched paired conventional squamous cell carcinomas were investigated for clinicopathologic features and immunoreactivity of cytokeratin subtypes, p53, B-cell lymphoma 2 (bcl-2), β-catenin, and epidermal growth factor receptor. Molecular aberrations in p53, CTNNB1 (the gene encoding β-catenin), and epidermal growth factor receptor (EGFR) were also determined. Patients with basaloid squamous cell carcinomas demonstrated a 5-year survival rate of 42%, significantly worse than those with well-differentiated squamous cell carcinoma (P<.01). Histologically, solid nests with central necrosis and a cribriform pattern were identified in almost all (≥95%) cases, and ductal differentiation was less frequent (45%) but associated with significantly better survival (P<.05). Compared with conventional squamous cell carcinomas, the basaloid squamous cell carcinomas were less immunoreactive for cytokeratin 14, cytokeratin 903, and membranous β-catenin (P<.01-.001) but more reactive for bcl-2, nuclear β-catenin, epidermal growth factor receptor, and Ki-67 (P<.05-.001). Direct sequencing showed mutations of p53 (36%), EGFR (14%), but not CTNNB1; fluorescent in situ hybridization detected amplification of the epidermal growth factor receptor gene (22%). In basaloid squamous cell carcinomas, low-level expression of cytokeratin 14/cytokeratin 903 and mutations of p53 and EGFR had a significant influence on worse survival (P<.05-.001). We conclude that the esophageal basaloid squamous cell carcinoma, a neoplasm with particularly aggressive biologic behavior, should be differentiated from conventional squamous cell carcinomas. In this context, immunohistochemical assessment of several markers might provide a useful adjunct diagnostic tool. Aberrations of p53 and epidermal growth factor receptor genes are possibly involved in progression of esophageal basaloid squamous cell carcinoma.