Immunohistochemical expression of bcl-2 protein in squamous cell carcinoma and basaloid carcinoma of the esophagus

Cutaneous metastasis from esophageal basaloid squamous cell carcinoma: A case report

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Cutaneous metastasis of esophageal cancer is rare.

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Basaloid squamous cell carcinoma (BSCC) of the esophagus is a relatively rare histologic variant of squamous cell carcinoma.

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We reported a case of cutaneous metastasis from esophageal BSCC and was successfully treated with multidisciplinary treatment.

Introduction and importance

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a relatively rare histologic variant of squamous cell carcinoma. Here, we reported a case of solitary cutaneous metastasis as the first symptom of esophageal BSCC and was successfully treated with multidisciplinary treatment.

Case presentation

A 67-year-old man visited a local hospital with symptoms of dysphagia and cutaneous nodules on his left shoulder. Fluorine-18 fluorodeoxyglucose positron emission tomography revealed hypermetabolic accumulations in the middle thoracic esophagus, right recurrent laryngeal nerve lymph node, and epidermis of the left shoulder. Esophagogastroscopy revealed an ulcerative and infiltrating type tumor in the middle thoracic esophagus. Based on histopathologic examination of the endoscopic biopsy and the resected cutaneous tumor, the patient was diagnosed as esophageal BSCC with cutaneous metastasis. The patient was treated with chemotherapy followed by chemoradiotherapy. The therapeutic effect was a complete response, which was sustained for 39 months.

Clinical discussion

Review of previous literature in the PubMed database revealed only been two case reports on cutaneous metastasis of BSCC. Advanced BSCC of the esophagus with distant metastasis has a poor prognosis. Therefore, in our case, future careful follow-up is required.

Conclusion

Esophageal BSCC with cutaneous metastasis can be successfully managed by multidisciplinary treatment, including local resection of the cutaneous metastasis, systemic chemotherapy, and chemoradiotherapy.

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.

Molecular Characteristics of Basaloid Squamous Cell Carcinoma of the Esophagus: Analysis of KRAS, BRAF, and PIK3CA Mutations and LINE-1 Methylation

BACKGROUND

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare carcinoma with distinct characteristics, and was recently recognized as a variant of squamous cell carcinoma (SCC). We previously revealed genetic and epigenetic alterations associated with esophageal SCCs in relation to clinical outcome, including mutations in KRAS, BRAF, and PIK3CA, p53 expression, and long interspersed nucleotide element-1 (LINE-1) methylation, a surrogate marker for global DNA methylation level. In this study, we explored these features in BSCC.

METHODS

A database of 502 esophageal cancers was used to evaluate the clinical and molecular characteristics of BSCC. KRAS, BRAF, and PIK3CA mutations and LINE-1 methylation were analyzed by pyrosequencing.

RESULTS

Of 502 tumors, 22 (4.4 %) were pathologically diagnosed as BSCC, and 440 (87 %) as SCC. No prognostic differences between BSCC and SCC cases were identified (p = 0.41). KRAS or BRAF mutations were not observed in BSCCs. While 23 % of SCC tumors harbored a PIK3CA mutation, all BSCC cases were wild-type for PIK3CA (p = 0.002), and there were no differences in p53 expression between BSCCs and SCCs (p = 0.57), as assessed by immunohistochemistry. Furthermore, BSCC tissues exhibited significantly lower levels of LINE-1 methylation than SCC tissues (p < 0.0001).

CONCLUSIONS

These findings imply that esophageal BSCC and SCC retain different cellular phenotypes with distinct genetic and epigenetic alterations; thus, tailored therapeutic strategies should be developed against each cancer type.

Correlation of STAT1 with apoptosis and cell-cycle markers in esophageal squamous cell carcinoma

We recently found evidence that STAT1 in esophageal squamous carcinoma (ESCC) cells exerts tumor suppressor function, and it regulates five key regulators of apoptosis or cell-cycle progression, including Bcl-2, Bcl-xL, survivin, cyclin D1 and p21. In this study, we confirmed these findings in four ESCC cell lines. Using immunohistochemistry, we also assessed the expression of these proteins in 62 primary tumors. The expression of these markers was heterogeneous, ranging 39 to 69% of the cohort. Significant correlation was found between STAT1 and three proteins (p21, Bcl-xL and survivin), whereas only a trend was identified for cyclin D1 and Bcl-2. We then correlated the expression of these proteins with several clinicopathologic parameters including lymph node metastasis, depth of invasion, clinical stage and overall survival. Significant correlations were found between Bcl-2 and deep invasion (p = 0.033), survivin and lymph node metastasis (p = 0.006), as well as cyclin D1 and clinical stage (p = 0.014). Patients with p21-positive tumors had a significantly longer survival compared to those with p21-negative tumors (p = 0.031). To conclude, our findings support the concept that STAT1 exerts its tumor suppressor effects in ESCC via modulating the expression of key regulators of apoptosis and cell-cycle progression.

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.

Basaloid squamous cell carcinoma of the esophagus: assessment for high-risk human papillomavirus and related molecular markers

Basaloid squamous cell carcinoma (BSCC) of the esophagus is rare, historically confused for adenoid cystic carcinoma, and recently shown to behave similar to conventional, keratinizing esophageal squamous cell carcinoma. At other sites (eg, oropharynx, anogenital tract) the basaloid phenotype is frequently associated with the presence of high-risk human papillomavirus (HPV). HPVs role in esophageal squamous cell carcinomas is less certain, and to our knowledge, a direct examination of esophageal BSCC for high-risk HPV has not been performed earlier. Nine cases of esophageal BSCC were retrieved from our surgical pathology files. Twenty-two cases of keratinizing esophageal squamous cell carcinoma served as controls. In situ hybridization (ISH) for high-risk HPV and immunohistochemistry for related molecular markers including p53, cyclin D1, and p16 (scored 0 to 4+ based on percentage of cells staining; p53 additionally scored for intensity) were performed. HPV ISH was nonreactive in all tested cases. Compared with controls, BSCC showed less immunoreactivity for p16 and p53 (P=0.003, 0.009). Esophageal BSCC is negative for high-risk HPV by ISH, distinguishing these lesions from other BSCCs. Differential p16 and p53 expression in BSCC suggests that these tumors are molecularly distinct from conventional esophageal squamous cell carcinomas.

Expression of PCNA and Bcl-2 in Basaloid Squamous Cell Carcinoma of the Larynx: A Controlled Study

We investigated the difference in the biologic nature of typical squamous cell carcinoma (SCC) and basaloid SCC (BSCC) of the larynx by studying proliferation and antiapoptotic markers. We performed an immunohistochemical analysis of the expression of proliferating cell nuclear antigen (PCNA) and bcl-2 protein in 15 patients with laryngeal BSCC and 15 stage-and site-matched controls with typical laryngeal SCC. We found no significant difference between the two groups in the PCNA index or the frequency of bcl-2 overexpression, nor did we find any significant difference in survival. Our findings indicate that the biologic nature of typical laryngeal SCC and laryngeal BSCC is similar. In addition, our follow-up data suggest that the clinical course of laryngeal BSCC is no worse than that of typical laryngeal SCC.

Metastatic basaloid-squamous cell carcinoma of the esophagus treated by 5-fluorouracil and cisplatin

Basaloid squamous cell carcinoma (BSC) of the esophagus is a rare malignant disease. We report here a patient with recurrent esophageal BSC, who was successfully treated by systemic chemotherapy containing 5-fluorouracil (5-FU) and cisplatin (CDDP). A 57-year-old woman was diagnosed as having squamous cell carcinoma of the esophagus upon endoscopic examination. Curative esophagectomy with lymph node dissection was performed under the thoracoscope. The pathological diagnosis of the surgical specimen was BSC. Five months after operation, the patient was diagnosed as having a recurrence of the BSC with metastases to the liver and spleen, and a right paraclavicular lymph node. She was given systemic chemotherapy consisting of continuous infusion of 800 mg/d of 5-FU and 3 h infusion of 20 mg/d of CDDP for 5 consecutive days every 4 wk. The metastatic lesions in the spleen and right paraclavicular lymph node disappeared, and the liver metastasis was apparently reduced in size after 2 courses of chemotherapy. The tumor regression was seen over 6 courses, with progression afterwards. Although subsequent treatment with CPT-11 and CDDP was not effective, docetaxel and vinorelbine temporarily controlled the tumor growth for 2 mo. 5-FU and CDDP combination may be useful for the patients with advanced BSC.

Recurrence and survival predictive value of phenotypic expression of Bcl-2 varies with tumor stage of colorectal adenocarcinoma

Although decreased or lack of expression of Bcl-2 has been correlated with advanced tumor stage and shortened patient survival in colorectal cancer (CRC), its value in predicting the recurrence has not been well explored. Therefore, we assessed the usefulness of phenotypic expression of Bcl-2 in non-Hispanic Caucasian patients with CRCs in identifying risk of recurrence. Archival tissues of 92 Stage II and 66 Stage III primary CRCs were evaluated for immunohistochemical expression of Bcl-2. None of these patients received either pre- or post-surgical adjuvant therapies. Kaplan-Meier and Cox proportional hazards methods were used to estimate the rates of recurrence and survival according to Bcl-2 expression. Decreased expression of Bcl-2 was associated with an increased rate of recurrence in patients with Stage II CRCs (5-year log-rank test P=0.0015; Hazard Ratio (HR)=3.90, 95%C.I.:1.55-9.77) but not with Stage III CRCs (5-year log-rank test P=0.6058; HR=1.07, 95%C.I.:0.47-2.45) after adjusting for other demographic and clinicopathological features. Furthermore, decreased expression of Bcl-2 was an indicator of short survival in patients with Stage II CRCs but not with Stage III CRCs. Thus, decreased or lack of Bcl-2 expression in primary CRCs may serve as a molecular biomarker of high risk of recurrence for Caucasian patients with Stage II CRCs. These findings might be useful in identifying biologically aggressive phenotypes of Stage II CRCs, and may aid the oncologist in designing maximally appropriate therapeutic regimens.

Immunohistochemical analysis of nuclear survivin expression in esophageal squamous cell carcinoma

Despite advances in the treatment of esophageal carcinoma, the prognosis for this disease remains poor. Therefore, it is important to obtain a better understanding of the molecular basis of esophageal carcinogenesis. The purpose of this study was to clarify the roles of survivin in esophageal squamous cell carcinoma (ESCC). One hundred 22 ESCC surgical specimens resected from 1989 to 1999 were examined. Survivin expression was assessed by immunohistochemistry. Tumor cells were considered survivin-positive if the immunoreactivity was confined to the nucleus, and a scoring method was applied. Survivin-positive immunostaining was detected in 68 patients (56%). There was a significant association between survivin expression and pN (P = 0.0472). Moreover, the overall survival rate was worse in patients with survivin-positive tumors than in patients with survivin-negative tumors (P = 0.0189). The overexpression of survivin was associated with the overall survival rate and poor prognosis in patients with ESCC. Survivin may be targeted during cancer therapy because of its selective expression in malignant tissue.

Spindle basaloid squamous carcinoma of the upper aerodigestive tract: immunohistochemical and clinicopathological study of three cases

We describe the clinicopathological and immunohistochemical features of three spindle (sarcomatoid) basaloid squamous carcinomas in three men aged 73, 69, and 59 years with a history of tobacco and alcohol abuse. Two tumors were located in the hypopharynx and one was located in the nasal cavity. The three tumors have a pedunculated polypoid appearance. Histologically, they were composed of conventional basaloid squamous carcinomas with extensive malignant spindle cell proliferation, comprising more than 50% of the tumor. The sarcomatoid component demonstrated immunoreactivity with one or more epithelial markers. One case in addition expressed CD99 and Bcl-2 and was originally diagnosed as monophasic synovial sarcoma; however, a subsequent biopsy disclosed basaloid squamous cell carcinoma with sarcomatoid stroma. Two patients were treated with surgery and radiation whereas one refused therapy. The patients were alive 14 (case patient 1), 10 (case patient 2), and 8 (case patient 3) months after diagnosis. In the absence of evidence from immunohistochemical or electron microscopy studies, a polypoid malignant spindle cell tumor of a mucosal surface of the upper aerodigestive tract should be considered a sarcomatoid carcinoma until proven otherwise. The type of epithelial component would determine the subtype of sarcomatoid carcinoma.

Expression of PCNA, p53, Bax, and Bcl-X in oral poorly differentiated and basaloid squamous cell carcinoma: Relationships with prognosis

BACKGROUND

The aim of this study was to compare the clinical features and proliferating cell nuclear antigen (PCNA), p53, Bcl-X, and Bax expression in primary oral basaloid squamous cell carcinoma (BSCC) and poorly differentiated squamous cell carcinoma (PDSCC) matched by stage and site and to assess the possible prognostic significance of these variables.

METHODS

Seventeen cases of oral BSCC were compared with 27 PDSCCs matched by stage and tumor site. In addition, PCNA, p53, Bax, and Bcl-X expression in both carcinomas were evaluated in relation to their clinicopathologic features and prognostic values using the Kaplan-Meier method and Cox regression models.

RESULTS

No statistically significant differences were found between the groups (BSCC and PDSCC) in regard to clinical features and immunohistochemical reactivity for antibodies PCNA, p53, and Bcl-X. In comparison with PDSCC, the BSCC group exhibited a higher Bax score (p = .031). The 5-year and 10-year overall survival, cancer-specific survival, and disease-free survival rates demonstrated no significant differences between the BSCC and PDSCC groups, and the PCNA, p53, Bax, and Bcl-X also showed no prognostic value.

CONCLUSIONS

These results suggest that the clinical and biologic course of BSCC is similar to PDSCC in the oral cavity when clinical stage and site are matched.

Two cases of superficial basaloid squamous carcinoma of the esophagus

. Basaloid squamous carcinoma of the esophagus is very rare. We report two cases of basaloid squamous carcinoma of the esophagus. Both tumors histologically consisted of solid cell nests with intervening fibromyxoid stroma. In some tumor nests were comprised of pseudoglandular structures containing myxoid matrix, and displayed focal immunoreactivity for laminin. Thoracic esophagectomy with lymph node dissection was followed by intrathoracic esophagogastrostomy in both patients. The patients had uneventful postoperative courses. Regular periodic follow-up showed no evidence of recurrence or metastasis in the 22-month postoperative period.

Hepatocellular carcinoma and markers of apoptosis (bcl-2, bax, bcl-x): prognostic significance

Patients with tumors expressing promoters of apoptosis (bax) versus inhibitors of apoptosis (bcl-2, bcl-x) may have increased survival. The purpose of this study was to determine the frequency of expression of apoptotic markers in hepatocellular carcinoma (HCC) and their relationship with prognosis. Seventy HCC were immunostained for bcl-2, bax, and bcl-x. Staining intensity in tumor cells was graded 0 to 3+. Follow-up data were available for mean survival (57 cases) and death rates (58 cases). These values and clinical parameters were related to prognosis. Staining frequency for bcl-2, bax, and bcl-x was 20%, 66%, and 60%, respectively. Immunostaining intensity of bax correlated with overall survival and death rates: of 57 patients, the 37% with 0 to 1+ intensity had a median survival of 6.6 months, the 63% with 2 to 3+ intensity had a median survival of 31.9 months (P = 0.05); 86% of 19 patients with 0 to 1+ intensity died, and 50% of 36 patients with 2 to 3+ intensity died (P < 0.05). Intensity of bcl-x staining tended to correlate with survival: of the 57 patients with 0 to 1+, 42% had a median survival of 32.7 months compared with 5.8 months in the 58% with 2 to 3+ intensity (P = 0.06). By multivariate analysis, this relationship held for bax (P = 0.011) and bcl-x (P = 0.048). There was no correlation between bcl-2 expression, stage, or gender and prognosis. Patients with bax-expressing HCC experience improved survival compared with those with no or low bax expression, in uni- and multivariate models. Patients with no or low bcl-x tended toward improved survival compared with patients with more bcl-x in their HCC. bcl-2 expression did not correlate with prognosis.

Digest

Dr Keizo Sugimachi, Editor-in-Chief of Surgery Today (The Japanese Journal of Surgery), has selected from the July to September 1997 issues of his journal for this quarter's digest. A digest of BJS for the same period written by Mr Colin Johnson, European Editor, appears in the Japanese journal.

Paradoxical role of apoptosis in tumor progression

Tumors frequently acquire resistance to apoptosis that is expected to contribute to malignant phenotype and reduce sensitivity to treatment. In fact, inactivation of p53 tumor suppressor gene resulting in suppression of apoptosis serves as a negative prognostic marker. Surprisingly, expression of a strong anti-apoptotic protein Bcl-2, another mechanism to avoid apoptosis, was found to be associated with a favorable prognosis. This paradoxical anti-progressor function of Bcl-2 has been explained in literature based on the negative effect of Bcl-2 on cell proliferation. Here, by analyzing accumulated experimental and clinical data, we provide evidence supporting another hypothesis that defines apoptosis as an accelerator of tumor progression. The mechanism of anti-progressor function of Bcl-2 is based on creation of tumors that maintain control of genomic stability by eliminating selective advantages for the cells that acquire resistance to apoptosis through loss of p53. Thus, inhibition of apoptosis does not lead to loss of genomic stability and creates tumor environment that no longer supports further tumor progression and inhibitors of apoptosis can be considered as factors suppressing tumor progression.

Hepatocellular carcinoma and markers of apoptosis (bcl-2, bax, bcl-x): prognostic significance

Patients with tumors expressing promoters of apoptosis (bax) versus inhibitors of apoptosis (bcl-2, bcl-x) may have increased survival. The purpose of this study was to determine the frequency of expression of apoptotic markers in hepatocellular carcinoma (HCC) and their relationship with prognosis. Seventy HCC were immunostained for bcl-2, bax, and bcl-x. Staining intensity in tumor cells was graded 0 to 3+. Follow-up data were available for mean survival (57 cases) and death rates (58 cases). These values and clinical parameters were related to prognosis. Staining frequency for bcl-2, bax, and bcl-x was 20%, 66%, and 60%, respectively. Immunostaining intensity of bax correlated with overall survival and death rates: of 57 patients, the 37% with 0 to 1+ intensity had a median survival of 6.6 months, the 63% with 2 to 3+ intensity had a median survival of 31.9 months (P = 0.05); 86% of 19 patients with 0 to 1+ intensity died, and 50% of 36 patients with 2 to 3+ intensity died (P < 0.05). Intensity of bcl-x staining tended to correlate with survival: of the 57 patients with 0 to 1+, 42% had a median survival of 32.7 months compared with 5.8 months in the 58% with 2 to 3+ intensity (P = 0.06). By multivariate analysis, this relationship held for bax (P = 0.011) and bcl-x (P = 0.048). There was no correlation between bcl-2 expression, stage, or gender and prognosis. Patients with bax-expressing HCC experience improved survival compared with those with no or low bax expression, in uni- and multivariate models. Patients with no or low bcl-x tended toward improved survival compared with patients with more bcl-x in their HCC. bcl-2 expression did not correlate with prognosis.

Immunohistochemical prognostic indicators of gastrointestinal carcinoid tumours

AIMS

The aim of this study was to determine whether expression of the oncoproteins p21, p53, E-cadherin (EC), cyclin D1, bcl-2 and Rb and the proliferation marker Ki-67 is predictive of malignant behaviour in gastrointestinal carcinoid tumours.

METHODS

Immunohistochemical (IHC) staining was performed on carcinoid tumours from 41 patients (31 rectal, eight gastrointestinal, two appendiceal lesions). The six tumours that had invaded deeply into the muscularis propria or beyond, had metastasized to regional lymph nodes or had metastasized to a distant site were classified as the malignant group, and the other 35 tumours formed the benign group. IHC expression was compared between the two groups, and the prognostic value of each marker was assessed.

RESULTS

Of the six tumours in the malignant group, 66.7% were p21 positive, 0% were p53 positive, 33.3% were EC positive, 100% were cyclin D1 positive, 33.3% were Rb positive, 16.7% were bcl-2 positive and 50% were Ki-67 positive. Of the 35 tumours in the benign group, 17.1% were p21 positive, 0% were p53 positive, 100% were EC positive, 94.3% were cyclin D1 positive, 8.6% were Rb positive, 17.1% were bcl-2 positive and 0% were Ki-67 positive.

CONCLUSIONS

These data show that p53, cyclin D1, Rb, bcl-2 and Ki-67 staining does not correlate with malignant behaviour but that overexpression of p21 (P=0.02) and reduced staining of EC (P=0.005) do correlate with malignant behaviour. These two parameters may therefore be useful as prognostic indicators for gastrointestinal carcinoid tumours.

Comparative analysis of basaloid and typical squamous cell carcinoma of the oesophagus: a molecular biological and immunohistochemical study

Twenty-three cases of basaloid squamous cell carcinoma (BSCC) and 23 stage-matched pairs of typical squamous cell carcinoma (SCC) of the oesophagus were investigated for molecular aberrations. Polymerase chain reaction (PCR) was used to detect loss of heterozygosity at the APC, RB, and MCC gene loci, while differential PCR was carried out to detect amplification of the CDK4 gene. In addition, the level of expression of the p53 and RB proteins in the tumour tissue was assessed by immunohistochemistry. Loss of heterozygosity (LOH) at the APC and MCC loci was about twice as common in BSCC as in SCC (40% vs. 21% and 33% vs. 12%, respectively), with co-existence of LOH at both loci occurring only in BSCC. LOH frequency at the RB gene locus was not remarkably different in either BSCC or SCC (20% vs. 24%, respectively). On immunohistochemistry, accumulation of p53 protein was slightly more frequent in BSCC than in SCC (61% vs. 52%), whereas the rate of loss of RB protein expression was about equal in both types of carcinoma (9% vs. 13% BSCC and SCC, respectively). There was no detectable amplification of the CDK4 gene in either type of tumour. Although the observed differences did not achieve statistical significance, this work has further highlighted possible differences between the molecular pathogenesis of BSCC and SCC.

Histochemical study of angiogenesis in basaloid squamous carcinoma of the esophagus

Angiogenesis of esophageal basaloid squamous carcinoma (BSC) was studied immunohistochemically and compared with that of squamous cell carcinoma (SCC). In tissues taken from six patients with esophageal BSC and 35 with esophageal SCC, angiogenesis was evaluated by measuring microvessel density (MVD), defined as the microvessel count determined using factor VIII-related antigen immunostaining, and by measuring immunoreactivity of vascular endothelial growth factor (VEGF) and thymidine phosphorylase (dThdPase). Three of the six patients with BSC had distant metastases. There was no difference of MVD between BSC and SCC (22.0 +/- 4.6 vs. 27.6 +/- 9.4). VEGF expression tended to be more frequently observed in BSC than in SCC (100% vs. 60.0%; p = 0.066). Strong expression of VEGF was detected in three BSC with distant metastases; however, there was no difference in the rate of strong VEGF expression between BSC and SCC. The MVD in the cases of BSC with strong VEGF expression, i.e. in the cases with distant metastases, was higher than that in the cases of BSC with weak VEGF expression (p=0.049). There was no difference in dThdPase expression of the cancer cells between BSC and SCC (50.0% vs. 54.3%), whereas the infiltrating stromal cells of all the BSC expressed dThdPase. Strong dThdPase expression in the cancer cells or in the infiltrating stromal cells was observed in two and three BSC, respectively. However, there were no differences in the rate of cancer cells or stromal cells with strong dThdPase expression between BSC and SCC. In one BSC with high MVD and distant metastases, VEGF and dThdPase were both strongly expressed. The vascularity of esophageal BSC was not different from that of SCC. VEGF may participate in angiogenesis of esophageal BSC and may influence the rate of metastasis in esophageal BSC patients. dThdPase may play a partial rule in angiogenesis and metastasis in some cases of BSC.

Molecular biology of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the predominant histologic subtype of esophageal cancer and characterized by high mortality rate and geographic differences in incidence. With the advances in the field of molecular biology, our understanding of the pathogenesis, epidemiology and behavior of ESCC continues to evolve. The recent development includes research in etiopathogenesis (viruses and cancer susceptibility genes), keratins, tumor related genes (oncogenes, tumor suppressor genes, genes involved in metastasis and apoptosis genes), proliferation-related factors (nuclear proteins, flow cytometry/morphometry, argyrophilic nucleolar organizer region) and factors related to metastases (cell adhesion molecules and enzymes related to degradation of extracellular matrix). There are ranges of molecular techniques potentially available to complement the traditional approaches in the management of ESCC. On the other hand, critics are needed in the interpretation and translation of these research findings from laboratories to clinics. Further investigations, education and collaborations between the various scientific and clinical disciplines are important to successful application of these molecular findings aiming at improving management of patients with ESCC.

Expression of Bcl-2 and amplification of c-myc are frequent in basaloid squamous cell carcinomas of the esophagus

Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare, poorly differentiated variant of typical esophageal squamous cell carcinoma (SCC) characterized by high proliferative activity and frequent spontaneous apoptoses. In the present study, we investigated the expression of the apoptosis-suppressing protein Bcl-2 in 23 BSCC of the esophagus and 23 stage-matched typical esophageal SCC by means of immunohistochemistry. In addition, amplification of the apoptosis- and proliferation-inducing gene c-myc was determined by means of differential polymerase chain reaction. Bcl-2 expression was found significantly more often in BSCC than in SCC (86.9% vs. 17.4%, P < 0.0001). Amplification of c-myc was nearly twice as common in BSCC as in SCC (47.8% vs. 26.1%, not significant). Bcl-2 protein expression together with c-myc amplification was detected in 43.5% of the BSCC but in none of the typical SCC (P < 0.0001). Taken together, our findings indicate that the molecular pathogenesis of esophageal BSCC differs from that of typical SCC and frequently involves coactivation of c-myc and Bcl-2.

Oral squamous cell carcinoma is associated with decreased bcl-2/bax expression ratio and increased apoptosis

Expression of bcl-2 and bax and apoptosis were studied in fresh frozen samples of normal oral epithelium (OE, n = 7) and oral squamous cell carcinomas (OSCC, n = 16) by immunohistochemistry and the TUNEL method. In OE, bcl-2 was expressed in both basal (96.6% +/- 2.3% [mean +/- SD]) and suprabasal (91.8% +/- 6.2%) compartments. In OSCC, compared with OE, there was a marked reduction of bcl-2-positive cells in the basal part, and in the central parts of well-differentiated (33.0% +/- 19.7%, P < .001) and moderately differentiated (6.1% +/- 4.6%, P < .001) and also in poorly differentiated (1.9% +/- 0.2%, P < .001) tumors. More cells expressed bax in the suprabasal layer of OE (65.6% +/- 9.9%) and central parts of OSCC than in the basal layer of OE (19.1% +/- 4.1%) and basal parts of OSCC. A higher proportion of cells expressed bax in the central part of well-differentiated OSCC (74.3% +/- 8.2%) than in poorly differentiated OSCC (24.9% +/- 9.7%, P < .001). Apoptotic cell death was more pronounced in OSCC (1.5% +/- 0.9%) than in OE (0.4% +/- 0.1%, P < .05). We conclude that, in OSCC, compared with OE, there is a decreased bcl-2 expression, a lowered bcl-2/bax ratio and increased apoptosis. The expression of bax correlates with histological tumor grading in oral squamous cell carcinoma.