Immunohistochemical expression of epidermal growth factor receptor in salivary gland tumours

The Therapeutic Landscape of Salivary Gland Malignancies-Where Are We Now?

Salivary gland malignancies (SGMs) account for less than 5% of new diagnoses in head and neck tumors. If feasible, surgery is the preferred treatment modality. Nevertheless, some malignancies have a tendency of recurrence, with possible distant metastasis. Alternative treatment strategies, such as primary radiation or chemotherapeutics, often present low response rates. As a result, there is an unmet need for novel therapeutic approaches. Nowadays, target-based therapies (e.g., small inhibitors and immunotherapy) are used by the medical oncologist for possible treatment of advanced SGMs. Based on recent published trials, some novel treatments may provide additional disease control for some patients. However, sample sizes are small, the general findings are unsatisfactory, and a lot of uncertainties remain to be elucidated. Nevertheless, research shows that patients do not benefit from blind administration of systemic treatments and therefore a more personalized approach is highly needed. The aim of this review paper is to summarize the most recent advances in the biological understanding and molecular pathways of salivary gland cancers, the association of these pathways with the current treatments used and their implications for more personalized targeted-based therapies.

A Single-Arm, Prospective, Phase II Study of Cisplatin Plus Weekly Docetaxel as First-Line Therapy in Patients with Metastatic or Recurrent Salivary Gland Cancer

PURPOSE

Salivary gland cancers (SGCs) are relatively rare but comprise various histologic subtypes, which complicates design of prospective trials. Systemic chemotherapy plays a limited role in treatment of SGCs, but cisplatin and docetaxel showed efficacy in a previous preclinical study. Here, we conduct a prospective, phase II study to evaluate the efficacy and toxicities of cisplatin plus weekly docetaxel in patients with metastatic or recurrent SGC.

MATERIALS AND METHODS

We included patients with histologically confirmed SGCs of the following subtypes: mucoepidermoid carcinoma, adenocarcinoma, ductal carcinoma, or adenoid cystic carcinoma. Patients had no prior systemic chemotherapy for metastatic or recurrent tumors and at least one measurable lesion. Patients were treated with docetaxel 35 mg/m2 (D1, 8) and cisplatin 70 mg/m2 (D1) every 21 days.

RESULTS

Forty-one patients were enrolled between April 2014 and October 2020. The median age was 58 years (range, 32 to 73 years). The most common histologic subtype was adenoid cystic carcinoma (63.4%), followed by ductal carcinoma (24.4%). The most common metastatic site was the lung (75.6%). The median treatment cycle was 5.5 (range, 3 to 8), and the objective response rate was 46.3%, with three complete responses. The median duration of response was 6.8 months (interquartile range, 4.0 to 10.2). The progression-free survival and overall survival were 9.4 months (95% confidence interval [CI], 8.4 to 10.5) and 28.2 months (95% CI, 22.7 to 33.6), respectively. There were no treatment-related deaths. The most common grade 3/4 adverse events were neutropenia (4.9%) and fatigue (4.9%).

CONCLUSION

Cisplatin plus weekly docetaxel is effective and tolerable with manageable toxicity as first-line therapy in patients with metastatic or recurrent SGC.

PCP4/PEP19 and HER2 Are Novel Prognostic Markers in Mucoepidermoid Carcinoma of the Salivary Gland

Simple Summary

Mucoepidermoid carcinoma (MEC) is the most common malignancy of all salivary neoplasms, and no effective treatment strategy for MEC has been established other than resection. In this study, we showed that Purkinje cell protein (PCP) 4/peptide (PEP) 19 and human epidermal growth factor receptor 2 (HER2) are predicted to play important roles in the pathogenesis and progression of MEC. The detection of PCP4/PEP19 and HER2 may be useful for providing more effective treatments against MEC.

Abstract

Mucoepidermoid carcinoma (MEC) is one of the most common malignant salivary gland carcinomas, but no effective treatment strategy has been established other than surgical resection. Purkinje cell protein (PCP) 4/peptide (PEP) 19 is a calmodulin-binding antiapoptotic peptide that is expressed and inhibits apoptosis in human breast cancer cells. Human epidermal growth factor receptor 2 (HER2) is an epidermal growth factor that has been implicated in the pathogenesis of many carcinomas, particularly breast and gastric carcinomas. In the present study, we performed immunohistochemical analyses of samples from 73 patients who underwent surgical resection for MEC of the salivary gland using antibodies against PCP4/PEP19 and HER2. PCP4/PEP19 expression was related to better prognosis, while HER2 expression was associated with worse prognosis. Patients that were PCP4/PEP19-positive and HER2-negative showed similar outcomes to PCP4/PEP19 and HER2 alone. Therefore, PCP4/PEP19 and HER2 are predicted to play important roles in the pathogenesis and progression of MEC.

Molecularly guided treatment of metastatic parotid gland carcinoma in adults

Background

Advanced therapy-refractory parotid gland carcinomas have a poor prognosis with limited therapy options. We used molecular profiling to offer molecular guided therapies to patients with advanced metastatic parotid gland malignancies.

Methods

In this retrospective analysis we describe the molecular profiling of ten patients diagnosed with therapy-refractory metastatic parotid gland malignancies.

Results

We identified seven genetic aberrations in five patients: two mutations in CDKN2A and one mutation in APC, ATM, TP53, SMARCB1 and FGFR1, respectively. No mutations were detected in five patients. The IHC demonstrated frequent expressions of EGFR and p‑mTOR, as well as PTEN in eight patients. For four fifths (n = 8) of the patients, a targeted therapy was suggested. Eventually, three patients received the targeted therapy recommendation and one patient achieved stable disease for 14 months.

Conclusion

A total of eight therapy recommendations were provided. Based on our observations, molecular-guided therapies may be a feasible treatment approach for this rare disease entity.

Salivary mucoepidermoid carcinoma revisited

Clinicopathological features, prognosis and therapeutic strategies for mucoepidermoid carcinoma originating in salivary and salivary-type glands of the head and neck are reviewed. We emphasise histopathological aspects, appraise the value of histochemistry, electron microscopy, immunohistochemistry and cytophotometry, and discuss histogenesis and characteristic gene translocations. We additionally consider possible diagnostic difficulties, problems related to histological grading and accuracy of existing literature, and areas of controversy or uncertainty which may benefit from further investigations.

Epidermal growth factor receptor (EGFR) in salivary gland carcinomas: potentials as therapeutic target

AIMS

Epidermal growth factor (EGFR) is involved in angiogenesis, cell differentiation, proliferation and progression of many cancers and is an important therapy target in lung and colorectal cancer. To determine the potential applicability of EGFR targeted therapies, EGFR status of over 800 salivary gland tumors of different entities were analyzed on DNA and protein level by FISH and IHC.

MATERIALS AND METHODS

A tissue microarray was constructed from 721 carcinomas and 205 adenomas of the salivary gland. EGFR expression and EGFR gene copy number was assessed by means of immunohistochemistry and fluorescence in situ hybridization (FISH). EGFR mutation analysis of exon 19 and 21 was performed in a subset of 107 carcinomas.

RESULTS

Positive immunohistochemical staining (definition?) for EGFR was shown in 324 of 663 (48.9%) salivary gland carcinomas. The frequency was dependent on the tumor entity and ranged from 17.9% (30 of 168 cases) positive immunostaining in acinic cell adenocarcinomas to 85.7% (42 of 49 cases) in Warthin tumors. No EGFR amplification was found by FISH. EGFR mutation analysis of Exon 19 and 21 in 107 salivary gland carcinomas revealed mutations in two acinic cell adenocarcinomas.

CONCLUSION

EGFR protein expression is common in salivary gland tumors but is not associated with gene amplification. Activating mutations of EGFR are rare. Nonetheless, selected cases of patients with salivary gland carcinomas might potentially benefit of anti-EGFR therapy.

Acinic cell carcinoma of minor salivary glands: a clinical and immunohistochemical study

PURPOSE

Acinic cell carcinoma is a rare malignant tumor of salivary glands. The purpose of this study is to evaluate the clinical outcome of acinic cell carcinoma in a group of 11 patients, who were treated in our clinic, and to discuss the management as well as the immunohistochemical features and prognosis of this carcinoma.

MATERIALS AND METHODS

The study included 11 patients with acinic cell carcinoma of the minor salivary glands who were treated in our clinic. The patients were 7 women and 4 men. The patients' age ranged from 46 to 83 years. The distribution of the primary sites was buccal mucosa (4) maxilla/maxillary sinus, etc, (2), hard palate (1), junction of soft/hard palate (1), lower lip (1), labio marginal sulcus (1), and vestibular sulcus and mandible (1). All patients were treated with surgery. Adjuvant radiotherapy was used in 3 patients. Immunohistochemical assay of expression of Ki-67, p53, EGFR, and c-erbB-2/neu markers was performed on specimens of all tumors.

RESULTS

The mean follow-up range was 2 to 15 years. Of the 11 patients, 7 were alive (2, 3, 4, 5, and 15 years after the initial therapy). Two patients died of another cause free of the disease 9 and 10 years after the initial treatment, and 2 patients died of the disease (local recurrence, distant metastases 2 and 3 years later). Overexpression of immunohistochemical markers was evident for tumors with widespread metastases.

CONCLUSIONS

Acinic cell carcinoma is a rare malignant tumor of the salivary glands, characterized by an indolent clinical course with the potential for both local recurrence and distant metastases. The immunohistochemical analysis of proliferation markers provides additional prognostic information for this tumor.

Study of growth factors and receptors in carcinoma ex pleomorphic adenoma

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignant salivary gland tumor derived from a pre-existing pleomorphic adenoma. It is a good model to study the evolution of carcinogenesis, starting with in situ areas to frankly invasive carcinoma. Growth factors are associated with several biological and neoplastic processes by transmembrane receptors. In order to investigate, by immunohistochemistry, the expression of some growth factors and its receptors [EGF receptor, fibroblast growth factor, fibroblast growth factor receptor 1, fibroblast growth factor receptor 2, hepatocyte growth factor, c-Met, transforming growth factor (TGF) beta1, TGFbetaR-II and insulin-like growth factor receptor 1] in the progression of CXPA, we have used ten cases of CXPA in several degrees of invasion- intracapsular, minimally and frankly invasive carcinoma- with only epithelial component. Slides were qualitatively and semi-quantitatively evaluated according to the percentage of stained tumor cells from 0 to 3 (0 = less than 10%; 1 = 10-25%; 2 = 25-50%; 3 = more than 50% of cells). Malignant epithelial cells starting with in situ areas showed stronger expression than luminal cells of pleomorphic adenoma for all antibodies. Most of the intracapsular, minimally and frankly invasive CXPA presented score 3. However, score 2 was more evident in the frankly invasive one. In small nests of invasive carcinoma, negative cells were observed probably indicating that the proliferative process is replaced by the invasive mechanism. Altogether this data infers that these factors may contribute to cell proliferation during initial phases of the tumor.

Fluorescence in situ hybridization gene amplification analysis of EGFR and HER2 in patients with malignant salivary gland tumors treated with lapatinib

BACKGROUND

Gene amplification status of the epidermal growth factor receptor (EGFR) and the human epidermal growth factor receptor 2 (HER2) were analyzed and correlated with clinical outcome in patients with progressive malignant salivary glands tumors (MSGT) treated with the dual EGFR/Her2 tyrosine kinase inhibitor lapatinib.

METHODS

Fluorescence in situ hybridization (FISH) analysis for both EGFR and HER2 gene amplification was performed successfully in the archival tumor specimens of 20 patients with adenoid cystic carcinomas (ACC) and 17 patients with non-ACC, all treated with lapatinib.

RESULTS

For ACC, no EGFR or HER2 amplifications were detected. For non-ACC, no EGFR gene amplifications were detected but 3 patients (18%) were HER2 amplified and all had stained 3+ for both EGFR and HER2 by immunohistochemistry (IHC) in their archival specimens. Two of these patients had time-to-progression (TTP) durations of 8.3 months and 18.4 months, respectively. Interestingly, patients with low and high HER2/chromosome-specific centromeric enumeration probe (CEP) 17 ratio had a prolonged TTP than those with moderate ratios for both ACC and non-AAC subtypes.

CONCLUSIONS

HER2 to CEP17 FISH ratio may predict which patients with MSGT have an increased likelihood to benefit from lapatinib. The finding of HER2:CEP17 ratio as a predictive marker of efficacy to lapatinib warrants further investigation.

Salivary gland-type lung carcinomas: an EGFR immunohistochemical, molecular genetic, and mutational analysis study

Salivary gland-type lung carcinomas are uncommon neoplasms of the lung, the two most common being adenoid cystic carcinoma and mucoepidermoid carcinoma. Although they usually have an indolent behavior, adenoid cystic carcinomas can be more aggressive, with 5-year survival as low as 55%. Unfortunately, these tumors do not respond well to chemotherapy. In contrast to the most common subtypes of lung carcinomas, epidermal growth factor receptor studies have not been carried out in this group of tumors. Herein we report a series of 24 cases (12 adenoid cystic and 12 mucoepidermoid carcinomas) tested for epidermal growth factor receptor protein expression, epidermal growth factor receptor gene copy gains, and epidermal growth factor receptor gene mutational status, through immunohistochemistry, fluorescence in situ hybridization, and sequencing of the exons 18-21, respectively. Overall, 91 and 92% of the adenoid cystic carcinomas and mucoepidermoid carcinomas expressed epidermal growth factor receptor protein. Chromosome 7 polysomy occurred in 25% of the cases (four adenoid cystic carcinomas and two mucoepidermoid carcinomas). No epidermal growth factor receptor gene amplification was detected and no mutation was found in exons 18-21 of the epidermal growth factor receptor gene. Immunoexpression of epidermal growth factor receptor in salivary gland-type lung carcinomas is not related to epidermal growth factor receptor gene copy number or mutational status.

Salivary gland malignancies: the role for chemotherapy and molecular targeted agents

Salivary gland tumors are a rare and clinically diverse group of neoplasms that represent less than 1% of all malignancies. In locoregional recurrent or metastatic disease, systemic therapy is the standard approach. Numerous phase II studies with small sample sizes have assessed the activity of different cytotoxic agents, either alone or in combination. For these agents, the objective response rates are generally modest, ranging from 15% to 50%. Duration of response is typically cited in the range of 6 to 9 months. Further evaluation of novel therapies is mandated in this disease. With the emergence of molecular targeted therapy, these tumors become optimal candidates for trials of investigational drugs and established drugs for new indications. Often, salivary gland carcinomas are indolent. As such, one should wish only to treat patients with progressive disease. Study designs must incorporate stringent inclusion criteria to enable accurate reporting of disease response and stabilization, especially in the evaluation of new drugs and novel combinations. Salivary gland-focused cooperative groups are necessary in order to accrue patients to these clinical trials and establish new treatment guidelines for these patients.

Phase II Study of Lapatinib in Recurrent or Metastatic Epidermal Growth Factor Receptor and/or erbB2 Expressing Adenoid Cystic Carcinoma and Non–Adenoid Cystic Carcinoma Malignant Tumors of the Salivary Glands

Purpose

Expression of erbB2 and/or epidermal growth factor receptor (EGFR) is associated with biologic aggressiveness and poor prognosis in malignant salivary gland tumors (MSGTs). This phase II study was conducted to determine the antitumor activity of lapatinib, a dual inhibitor of EGFR and erbB2 tyrosine kinase activity, in MSGTs.

Patients and Methods

Patients with progressive, recurrent, or metastatic adenoid cystic carcinoma (ACC) immunohistochemically expressing at least 1+ EGFR and/or 2+ erbB2 were treated with lapatinib 1,500 mg daily, in a two-stage cohort. Patients with non-ACC MSGTs were treated as a separate single-stage cohort.

Results

Of 62 patients screened, 29 of 33 (88%) ACC and 28 of 29 (97%) non-ACC patients expressed EGFR and/or erbB2. Forty patients with progressive disease were enrolled onto the study. Among 19 assessable ACC patients, there were no objective responses, 15 patients (79%) had stable disease (SD), nine patients (47%) had SD ≥ 6 months, and four patients (21%) had progressive disease (PD). For 17 assessable non-ACC patients, there were no objective responses, eight patients (47%) had SD, four patients (24%) had SD ≥ 6 months, and nine patients (53%) had PD. The most frequent adverse events were grade 1 to 2 diarrhea, fatigue, and rash. Eight paired tumor biopsies for correlative studies were procured; results did not correlate with clinical outcome.

Conclusion

Although no responses were observed, lapatinib was well tolerated, with prolonged tumor stabilization of ≥ 6 months in 36% (95% CI, 21% to 54%) of assessable patients. The antitumor effects of lapatinib in MGSTs appear mainly cytostatic, hence evaluation of other molecular targeted agents, or combinations with lapatinib, may be considered. Continued efforts should be made to gain better understanding into the biology of this heterogeneous group of malignancies.

Malignancies of the head and neck: the role for molecular targeted agents

Although cancers arising in the head and neck region are a diverse group of malignancies, a unifying thread remains a poor overall survival for patients with advanced, recurrent or metastatic disease. Treatment strategies need to evolve and improve upon established therapeutic practices. As the process of cancer evolution is understood to be derived from aberrations in genetic and epigenetic processes, molecularly targeted agents offer attractive therapeutic options by restoring normal control of oncogenic processes. The direct role for the treatment of squamous cell carcinoma of the head and neck, nasopharynx and salivary gland carcinomas with these novel, molecularly targeted agents are reviewed and their potential to improve on the existing standard of care is further explored.

Carcinoma ex pleomorphic adenoma of the salivary gland: an immunohistochemical study

The proliferative activity of the tumor cells and the expression of tumor-associated genes and sex steroid hormone receptors were investigated immunohistochemically in ten cases of carcinoma ex pleomorphic adenoma (Ca-ex-PA) of the salivary glands. These were analyzed in benign and malignant components separately, and then were compared with ten cases of the other malignant tumors [adenocarcinomas, not otherwise specified (ACN) and salivary duct carcinomas (SDC)] and ten cases of pleomorphic adenomas (PA). The results obtained in this study were as follows: (1) malignant component of Ca-ex-PA showed a higher incidence of PCNA and Ki67 than benign component of Ca-ex-PA. A significant difference between benign component of Ca-ex-PA and PA was not observed. (2) A significant difference in the incidence of p53, c-erbB-2, EGFR overexpression was observed only between malignant component of Ca-ex-PA and benign component of Ca-ex-PA. (3) The incidence of PCNA, Ki67, p53, c-erbB-2 overexpression in malignant component of Ca-ex-PA showed the highest data among the four groups. These results suggest that Ca-ex-PA acquired the particular biological behavior in contrast to the other salivary neoplasms in the long-standing process while PA undergoes malignant transformation.

Subcellular localization of epidermal growth factor receptor in human submandibular gland

The subcellular distribution of the epidermal growth factor receptor (EGFr) was demonstrated in the normal human submandibular gland by means of immunogold cytochemistry. EGFr labelling appeared in both acinar and ductal cells, where strong immunoreactivity was associated with a tubulovesicular system near the basolateral surfaces. In addition, groups of reactive vesicles were highlighted among secretory granules of both serous and mucous cells and at the apex of ductal cells. Basolateral vesicles were interpreted as being a result of EGFr internalization after activation by an exogenous ligand, although the functional meaning of those located apically remains unclear.

Interlobular excretory ducts of mammalian salivary glands: structural and histochemical review

In the major salivary glands of mammals, excretory ducts (EDs) succeed striated ducts. They are for the most part interlobular in position, although their proximal portions sometimes are on the periphery of a lobule, where they occasionally retain some of the structural features of striated ducts. Based on a survey of a broad range of mammalian species and glands, the predominant tissue type that composes EDs is pseudostratified epithelium. In some species, there is a progression of epithelial types: the proximal EDs are composed of simple cuboidal or columnar epithelium that, in the excurrent direction, usually gives way to the pseudostratified variety. Secretory granules are visible in the apical cytoplasm of the principal cells of the EDs of only a few species, but histochemistry has shown the presence of a variety of glycoproteins in these cells in a spectrum of species. Moreover, the latter methodology has revealed the presence of a variety of oxidative, acid hydrolytic, and transport enzymes in the EDs, showing that, rather than simply acting as a conduit for saliva, these ducts play a metabolically active role in gland function. It is difficult to describe a "typical" mammalian ED because it can vary along its length and interspecific variation does not follow a phylogenetic pattern. Moreover, in contrast to intercalated and striated ducts, ED cellular features do not exhibit a relationship to diet.

Phase II trial of taxol in salivary gland malignancies (E1394): A trial of the Eastern Cooperative Oncology Group

BACKGROUND

Malignant tumors of the salivary glands make up approximately 5% of head and neck cancers. The Eastern Cooperative Oncology Group (ECOG) initiated a phase II evaluation of paclitaxel in patients with locally recurrent or metastatic salivary gland malignancies.

METHODS

Chemo-naive patients with histologically confirmed recurrent or metastatic carcinoma of salivary gland origin (mucoepidermoid, adenocarcinoma, or adenoid cystic) were eligible. Patients were treated with paclitaxel, 200 mg/m(2) IV, every 21 days for a minimum of four cycles.

RESULTS

Forty-five patients were treated. Eight partial responses were seen among the 31 patients with mucoepidermoid or adenocarcinoma histologic findings for a response rate of 26%. No responses were seen in the adenoid cystic carcinoma group. No significant difference in overall survival was found among these three histologic subgroups.

CONCLUSION

Paclitaxel demonstrates moderate activity in salivary gland tumors of mucoepidermoid and adenocarcinoma histology. The poor response rate in adenoid cystic carcinoma is consistent with prior reports in this chemoresistant histologic subtype.

Extra-cellular signal-regulated ERK-1/ERK-2 pathway activation in human salivary gland mucoepidermoid carcinoma: association to aggressive tumor behavior and tumor cell proliferation

Information on oncogenetic events accompanying salivary gland mucoepidermoid carcinoma is so far limited. Activation of extracellular signal-regulated kinases ERK-1 and ERK-2 is strongly correlated to cancer. Using an antibody specific for phosphorylated (active) ERK-1/ERK-2, we examined human salivary gland mucoepidermoid carcinoma samples by immunohistochemistry. The comparison in paired tumor and normal tissue samples showed that phosphorylated ERK-1/ERK-2 immunoreactivity was higher in tumor cells as compared to surrounding normal salivary parenchyma. ERK-1/ERK-2 phosphorylation was observed in approximately 39% of mucoepidermoid carcinomas. Those tumors where the ERK-1/ERK-2 pathway was activated had a more aggressive tumor behavior as compared to the group where this pathway was inactive. The association of ERK-1/ERK-2 phosphorylation to a worse prognosis was independent of histological grade. ERK-1/ERK-2 phosphorylation was associated with increased Ki67 and cyclin A indexes, which indicated that ERK-1/ERK-2 pathway activation increased tumor cell proliferation. There was no relationship between ERK-1/ERK-2 phosphorylation and HER-2/neu or p16/INK4a protein expression. In conclusion, ERK-1/ERK-2 pathway is active in salivary gland mucoepidermoid carcinoma and this activation is associated to a more aggressive tumor behavior and a higher proliferative activity. These data suggest that deregulation of ERK-1/ERK-2 pathway contributes to mucoepidermoid carcinoma phenotype and, possibly, represents a target for new anticancer drugs.

Immunohistochemical study of epidermal growth factor receptor in adenoid cystic carcinoma of salivary gland origin

BACKGROUND

Epidermal growth factor (EGF) and its receptor (EGFR) are involved in the development of salivary gland tumors. Recently, treatment modalities for EGFR inhibition have shown an enhanced clinical response in carcinomas of different locations. Adenoid cystic carcinoma (ACC) of salivary gland origin is a malignant tumor with a poor long-term outcome. If salivary gland ACC does exhibit EGFR, then immunotherapy could have a major impact on improving its prognosis.

METHODS

The study consisted of 34 samples of formalin-fixed, paraffin-embedded specimens of salivary gland ACC. Specimens were stained with a mouse antihuman monoclonal antibody for immunohistochemical detection of EGFR. Overlying oral mucosa and adjacent normal salivary ducts served as internal controls. Both membrane and cytoplasmic staining were evaluated. Staining score was calculated by multiplying the percentage of positively stained tumor cells by the intensity of the staining. The highest score for a given tumor was equal to 2.

RESULTS

In the final analysis, 27 of the 34 specimens were included; 7 were excluded, because the internal control did not reveal any staining. Of these 27 specimens, 23 (85%) stained positively for EGFR with a staining score of 0.05 to 1.8. Three palatal tumors attained the highest scores (one tumor, 1.2, and the remaining two, 1.8).

CONCLUSIONS

Most salivary gland ACC stained positively for EGFR, and in some the staining was quite intense. On the basis of the already proven antitumoral effect of agents acting as EGFR inhibitors, it is suggested that patients with ACC might benefit from these agents, especially when surgery has failed or in those with recurrent or metastatic disease.

Molecular differences in mucoepidermoid carcinoma and adenoid cystic carcinoma of the major salivary glands

OBJECTIVE/HYPOTHESIS

Mucoepidermoid carcinoma (MEC) and adenoid cystic carcinoma (ACC), the most common malignancies of the major salivary glands, are clinically and pathologically different. To determine whether MEC and ACC have different molecular characteristics, we examined the expression of erbB-2, erbB-3, epidermal growth factor receptor (EGFR), and transforming growth factor-alpha (TGF-alpha), important molecular features in other malignancies.

STUDY DESIGN/METHODS

Archival tissue sections of 22 MEC and 6 ACC tumors of the major salivary glands were evaluated immunohistochemically for expression of erbB-2, erbB-3, EGRF, and TGF-alpha. A differential immunostaining score, reflecting the difference in immunostaining between carcinoma and uninvolved salivary gland tissue, was calculated for cytoplasmic and membranous staining.

RESULTS

Positive immunostaining for all biomarkers was observed in the cytoplasm and membrane of both tumors. However, expression was higher in MEC than in ACC tumors and was statistically significant for cytoplasmic EGFR (P =.009), TGF-alpha (P =.041), and membranous EGFR (P =.004). A significantly higher percentage of MEC cells also demonstrated positive immunostaining for cytoplasmic erbB-3 (P =.022), EGFR (P =.005), membranous erbB-3 (P =.022), and EGFR (P =.013). The differential immunostaining score was significantly higher for MEC compared with uninvolved alveolar tissue and the membranes of uninvolved ductal tissue. There were no statistically positive differential immunostaining scores for ACC.

CONCLUSIONS

There is a clear difference in the molecular phenotypes of MEC and ACC. The lack of statistically significant expression in ACC, when compared with similar uninvolved salivary gland tissue, suggests minimal involvement for these molecular structures in the pathogenesis of ACC. Conversely, erbB-2, erbB-3, EGFR, and TGF-alpha may have a role in the development and progression of MEC. These results have therapeutic implications for MEC of the major salivary glands.

Oncogens in ENT and head and neck - a review

With the exploration of new horizons in the frontiers of genetic linkage with head and neck cancer by advanced molecular biological technique it may be possible to know the various steps involved in the cancer development and new prognostic markers for not only predicting prognosis but also progression and predisposition including routine diagnostic tests for mutantgenes for a better diagnosis and treatment of squamous cell cancers of head and neck. Various oncogens and their products so far identified are ras, myc, c-erb, Bl, PRAD-.l, int-2, hst-1 and p 53 etc with lirikage to head and neck malignancy. The HLA gene association is the most convincing evidence for the role of genetics in the aetiology of nasopharyngeal cancer. EGFR looks to be a promising prognostic indicator as its interaction with the polypeptide epidermal growth factor stimulates proliferation of target cells.

Species differences in the expression of transforming growth factor-alpha (TGF-alpha) in the submandibular gland and pancreas

CONCLUSION

Significant differences exist in the expression of transforming growth factor-alpha (TGF-alpha) in the submandibular glands (SMG) and the pancreas of different species and among cell components in the same species.

BACKGROUND

Our previous studies have shown marked differences in the expression of TGF-alpha in the pancreas of humans and Syrian hamsters. To examine whether these differences also exist in other species, we examined the expression of TGF-alpha in the pancreas of mouse, rat, Syrian hamster, guinea pig, rabbit, pig, dog, and monkey. We included the SMG of these species for comparison.

MATERIALS AND METHODS

The formalin-fixed tissues of these species (n = 3) were investigated by immuno-histochemistry using a monoclonal antibody to TGF-alpha. The SMG of rat, mouse, hamster, rabbit, pig, dog, and monkey were examined by RT-PCR to assure the specificity of the antibody.

RESULTS

Remarkable species differences were found in the expression of this peptide in both the SMG and the pancreas. In the SMG, the expression varied in different cell components, even in the same tissue of the species. Although excretory and secretory ducts of the SMG of most species reacted with the antibody, intercalated ducts were immunoreactive only in mouse and guinea pig. Acinar cells were either weakly positive or nonimmunoreactive. In the pancreas of most species, the cells of the large and medium-sized ducts expressed TGF-alpha, whereas centroacinar cells of only rat and dog reacted with the antibody. Marked differences were found in the expression of TGF-alpha in islet cells and in its spatial distribution. Differences were also found in the immunoreactivity of mesenchymal and neural cells among the species.

Epidermal growth factor receptor in vulvar malignancies and its relationship to metastasis and patient survival

OBJECTIVE

To evaluate the level of epidermal growth factor receptor (EGF-R) expression in vulvar malignancies and to determine if a correlation exists between EGF-R levels and metastasis or patient survival.

METHODS

All patients with a diagnosis of invasive squamous cell carcinoma of the vulva who were treated at our institution with a primary radical vulvectomy and inguinal lymph node dissection from 1983 to 1993 were eligible for the study. Sixty-one patients with available tissue blocks of benign vulvar epithelium, the primary malignant vulvar lesion, and groin node metastasis (when positive) were included in the study. Semiquantitative EGF-R expression was determined in a blinded fashion utilizing immunohistochemical staining of appropriate tissue samples. Survival was calculated utilizing Kaplan-Meier life table analysis based upon disease-free survival.

RESULTS

A significant increase (P < 0.001) in mean EGF-R levels was demonstrated in the primary tumor (67%) versus benign vulvar epithelium (31%). In the 14 patients with lymph node metastasis, the mean EGF-R level in the primary tumor was 65% versus 88% in the metastatic lesion (P < 0.001). The likelihood of lymph node metastasis was elevated in those patients with a benign tissue EGF-R level > or =40% (P < 0.03) and in those patients with a primary tumor EGF-R level > or =90% (P < 0.025). Life table analysis revealed a cumulative disease-free survival of 45% for all patients. Disease-free survival in those patients with EGF-R levels > or =90% in the primary tumor was 25%, contrasting with a disease-free survival of 54% in those patients with EGF-R levels <90% (P < 0.05).

CONCLUSIONS

There is a progressive increase in EGF-R expression from benign vulvar epithelium to primary malignant tissue to metastatic lesions within the same patient. Increased expression of EGF-R in the primary vulvar malignancy is significantly associated with lymph node metastasis and decreased patient survival. Increased expression of EGF-R in histologically benign vulvar epithelium has a significant association with lymph node metastasis and may predict decreased patient survival.

Parathyroid hormone-related peptide: immunolocalisation in normal salivary glands and in pleomorphic adenomas

Parathyroid hormone-related peptide (PTHrP) has been shown to be produced as an early step in the differentiation sequence and is considered to be a marker of some progenitor cells. We investigated the presence and distribution of PTHrP in 7 normal parotid glands and in 18 salivary pleomorphic adenomas (PA). Localisation of PTHrP was studied by immunohistochemistry with a three-step unlabelled peroxidase-antiperoxidase method. In the normal glands PTHrP is found mainly in the basal and dark cells, and to a lesser extent in the light cells of the ducts. In PA the inner layer of tubulo-ductal structures and all cells of the cyst-like structures show strong positivity for PTHrP. Scattered cells in the dense clusters also stain strongly. Virtually all tumour cells in myxoid and chondroid areas are devoid of staining. In clusters of squamous metaplasia, most cells are slightly positive and scattered cells are stained strongly. PTHrP contributes to cellular differentiation and is also related to keratinisation. We suggest that the PTHrP-positive inner layer cells in pleomorphic adenomas represent a step in the squamous differentiation and in the further elaboration of the tubulo-ductal structures.

Prognostic utility of epidermal growth factor receptor overexpression in endometrial adenocarcinoma

BACKGROUND

Overexpression of epidermal growth factor receptor (EGFR) has been reported in endometrial adenocarcinoma.

METHODS

A retrospective analytic study was designed to investigate its prognostic utility. Sixty-nine patients were studied with cell types that included endometrioid (n = 45), papillary serous (n = 16), and clear cell (n = 8). Patients' medical charts and survival data were reviewed. Assessment of EGFR overexpression was done at the protein level by the use of an anti-EGFR polyclonal antibody that reacts with the cytoplasmic membrane glycoprotein receptor in paraffin-embedded tissues.

RESULTS

EGFR was overexpressed in 34 (49%) patients in whom immunoreactivity was limited to neoplastic cells. Initial bivariate analysis revealed significant correlations between EGFR immunoreactivity and histologic grade (r = 0.44, P < 0.001), metastasis (r = 0.38, P < 0.001), cell type (r = 0.30, P < 0.01), myometrial invasion (r = 0.30, P < 0.01), and patient age (r = 0.30, P < 0.01). Multiple logistic regression analyses showed that EGFR overexpression and nonendometrioid cell types are two independent statistically significant markers for the presence of metastases. EGFR immunoreactivity can significantly predict myometrial invasion, but after controlling for the histologic grade, its ability of significantly predict invasion was lost. EGFR overexpression was shown to be a statistically significant predictor of survival, even after controlling for patient age, histologic grade, and cell type.

CONCLUSIONS

Expression of this oncoprotein may serve as an independent prognostic indicator and a guide to therapy in patients with endometrial cancer.

Epidermal growth factor receptors and oestrogen receptors in the head and neck

We report a pilot study of the levels of epidermal growth factor receptors (EGFR) in normal and neoplastic tissues of the head and neck. Specimens from 20 consecutive patients undergoing major head and neck surgery showed that squamous cell carcinomas had detectable but widely varying levels of EGFR. EGFR expression was greater in normal salivary gland tissue than in benign salivary neoplasms. Oestrogen receptors were not detected in clinically significant amounts in any of the tumours assayed.

Rare expression of the c-erbB-2 oncoprotein in salivary gland tumors: an immunohistochemical study

An immunohistochemical study of c-erbB-2 oncoprotein expression was carried out on 201 cases of primary salivary gland tumors, using a polyclonal antibody, raised to the intracytoplasmic domain of the c-erbB-2 oncogene product. An intense membrane reactivity was observed in one case of sialocarcinoma transformed from pleomorphic adenoma (n = 8) and one case of mucoepidermoid carcinoma (n = 22). A comparative histopathologic evaluation of c-erbB-2 positive tumors showed marked variation in cell size, nuclear pleomorphism, multinucleation, a high mitotic rate and increased lymphoid cell infiltration and an aggressive clinical course with poor survival. The results indicate that c-erbB-2 oncoprotein is rarely expressed in malignant salivary gland tumors. However, the overexpression appears to have a distinct histopathologic feature, but a larger study incorporating histopathology and clinical data would be necessary to correlate the significance of c-erbB-2 oncogene product in salivary malignant tumors.

Epidermal growth factor receptor in odontogenic cysts and tumors

The expression of epidermal growth factor receptor (EGFR) was investigated in 67 cases of odontogenic cysts and 35 cases of odontogenic tumors using monoclonal antibody to EGFR (Biomarker, Israel) to determine the presence and significance of this transmembrane growth factor receptor. The cystic epithelial cells of odontogenic cystic lesions (keratocyst 60%; primordial cyst 75%; radicular cyst 35%; and follicular cyst 47.4%) were positive to EGFR staining. Cytochemical characterization of EGFR in those cystic epithelium was cell membrane positive type as in the normal epithelium. No expression of EGFR was found in the odontogenic tumors. This diversity of EGFR represents no binding activity of EGF, or loss of EGFR in the tumor cell upon EGFR mediated growth in odontogenic tumors was suggested a different tumor cell growth factor status or microenvironment in cell proliferation mechanism at the cellular level in cysts and tumors of odontogenic origin.

Expression of epidermal growth factor receptor in glottic carcinoma and its relation to recurrence after radiotherapy

The expression of EGFR was determined immunohistochemically in two groups of patients with glottic carcinoma, one that recurred after a full course of radiotherapy and one that did not. Using a 4-graded scale (-,+,++, ) 80% (12/15) of the recurrent carcinomas had a staining intensity and proportion of stained cells of ++ or more. The same figure for non-recurrent carcinomas was 39% (7/18). The difference is statistically significant (chi-squared with Yates' correction, P less than 0.05). The results indicate that an increased expression of EGFR may influence the rate of recurrence of glottic squamous cell carcinoma after radiotherapy.

Expression of EGF-receptors on epithelial and stromal cells of normal and inflamed gingiva

Immunolocalization techniques were used to examine the expression of the cell surface receptors of EGF in normal and inflamed gingival tissue. Detectable levels of receptor were not observed in any (0/6) of the normal tissue biopsies examined; in contrast, the EGF-receptor was expressed by both epithelial and stromal cells in 7/9 of the inflamed tissue biopsies. Receptor expression by epithelial cells in inflamed tissues exhibited a variable distribution pattern. In the majority of sections, staining was confined to cells in the spinous, granular and cornified cell layers, with little in the basal layer. Occasionally, isolated islands of stained epithelial cells were present, suggesting their clonal origin. Staining for the EGF receptor was also observed in fibroblasts and endothelial cells throughout the lamina propria of inflamed tissue. Positive staining for the receptor ligand (EGF) was observed in both normal and inflamed tissue. These data suggest that an up-regulation of cell surface receptors for EGF occurs during the inflammatory response, this resulting in an increased cellular responsiveness to EGF.

Immunohistochemical distribution of MAM-3 and MAM-6 antigens in developing salivary glands of the human fetus

The immunohistochemical expression of MAM-3 and MAM-6 antigens was studied developing human fetal salivary gland removed at autopsy of 22 normal fetuses of varying maturity (10-40 weeks of gestation). The onset of functional maturation in the fetal gland was seen at 21 weeks of gestational maturity. The acini and ducts then underwent distinct alterations in antigen expression with growth and maturation until the late developmental stage (33-40 weeks of gestation) when they resemble the adult salivary gland. The role of maturing duct cells in histogenesis of salivary gland tumours is discussed.

Prenatal development of human major salivary glands and immunohistochemical detection of keratins using monoclonal antibodies

The major salivary glands were examined from 69 human fetuses ranging from 10 to 40 weeks of gestation. Prenatal growth curves of developing salivary glands could be established by histological scoring, and development was divided into the early developmental stage (EDS) from 10 to 18 weeks, early intermediate developmental stage (EIDS) from 19 to 24 weeks, late intermediate developmental stage (LIDS) from 15 to 32 weeks, late developmental stage (LDS) from 33 to 40 weeks. Characteristic morphogenesis and cytodifferentiation occurred in glandular duct cells during the period of EIDS and LIDS. In the LDS, acini and ducts of the salivary glands histologically developed into a mature state similar to adult glands. Immunohistochemical staining with monoclonal antibodies (MoAbs) PKK1, KL1, K8.12, K8.13, K4.62, RPN 1160, 1162, 1163, 1164, and 1165 was performed. During the fetal period, keratin expression as revealed by MoAbs PKK1, KL1, K8.12 was well established, and the staining pattern for each of these antibodies was comparable. Other antibodies showed rare or negative staining except K8.13 which had a diffuse, non-specific staining pattern. Accordingly, the proliferation and cytodifferentiation of fetal stage keratin staining in ductal cells as revealed by MoAbs PKK1, KL1, and K8.12 showed a heterogenic distribution in both luminal and basal cells. It is a characteristic finding that the cytodifferentiation of ductal luminal cells precedes ductal basal cells. Ductal basal cells stained with MoAb K8.12 and show heterogeneity of keratin distribution continuously until the full term of gestation. The keratin staining of oral epithelium was also examined to compare with distribution of salivary gland ductal cells and oral epithelial cells. In the present study, the developmental sequence of salivary gland cells and the immunohistochemical properties of keratin proteins in these cells were described in relation to the histogenesis of salivary gland tumours.