Prognostic significance of biomarkers (c-erbB-2, p53, proliferating cell nuclear antigen, and DNA content) in salivary duct carcinoma

HER2-targeted therapies for salivary gland cancers

Salivary gland cancers (SGCs) are a heterogeneous group of rare tumors including various histological subtypes with different molecular profiling. Human epidermal growth factor receptor 2 (HER2) is one of the most intriguing and studied molecular alterations with prognostic and predictive roles. Indeed, HER2 overexpression is commonly correlated with aggressive histological subtypes and poorer prognosis. However, HER2 may represent the target of personalized treatment. We performed a literature review of use of anti-HER2 targeted agents for treatment of recurrent or metastatic SGCs. The efficacy and safety of anti-HER2 were firstly evaluated in patients affected with other solid tumors, mostly breast and gastric cancers. For SGCs the literature is mainly comprised of case reports or case series and small clinical trials. The most common used drug is trastuzumab in combination with chemotherapy (i.e. taxanes, capecitabine, carboplatin, eribulin) or with another anti-HER2 targeted agent (i.e. pertuzumab). The use of anti-HER2 therapies induces improvement in clinical responses, which are mostly durable. Besides, new anti-HER2 drugs such as antibody-drug conjugates (ADC) (i.e. trastuzumab emtansine, trastuzumab deruxtecan) have been introduced in this setting inducing further therapeutic advances. Anti-HER2 treatment strategy is emerging as potentially effective in selected HER2 overexpressing SGCs. However, prospective and multicentric clinical trials are needed to evaluate the efficacy of these therapeutic regimens within larger cohorts and to assess the most appropriate treatment sequence strategy.

Role of HER2 in Prognosis of Salivary Duct Carcinoma: A Systematic Review and Meta-Analysis

OBJECTIVES

Salivary duct carcinoma (SDC) is a rare, aggressive malignancy with a poor prognosis. These tumors frequently stain positive for HER2/ErbB2, but data on the prognostic significance of HER2 status in SDC are mixed. We sought to determine whether HER2 status affects survival outcomes in SDC.

METHODS

PubMed, Embase, and Web of Science databases were searched from inception to October 2020. Eligibility was restricted to studies reporting HER2/ErbB2 overexpression in histologically confirmed de novo SDC or SDC ex pleomorphic adenoma, with corresponding overall (OS) and disease-free (DFS) survival measures. Separate multivariable and univariable meta-analyses were performed using random-effects models. Statistical heterogeneity was estimated by Cochran's Q and I² tests. Funnel plots were generated and Egger's test was used to assess for publication bias. The risk of bias was assessed with the Newcastle-Ottawa Scale.

RESULTS

Of 183 unique citations, 14 studies of 663 patients were included. Most included studies determined HER2 status according to ASCO/CAP guidelines. The univariable meta-analysis did not reveal an effect between HER2 status and OS (HR 1.09, 95% CI 0.84-1.42). In the multivariable analysis, HER2 positivity was associated with a HR of 1.49 for OS (95% CI 0.96-2.30). Fewer studies reported data for DFS than OS, with no relationship between HER2 status and DFS found on multivariable or univariable meta-analyses.

CONCLUSION

In patients with salivary duct carcinoma, HER2 positivity was not found to be associated with worse overall survival. This information may be useful when counseling patients and considering treatment options. Laryngoscope, 133:476-484, 2023.

Case report: ado-trastuzumab as second-line treatment in HER2 positive salivary duct carcinoma

The objective of this report is to present the use and efficacy of ado-trastuzumab as an advanced line of therapy in salivary duct carcinoma (SDC) patient. An 84-year-old gentleman diagnosed with metastatic salivary duct tumor harboring overexpressed human epidermal growth factor receptor-2 has gone through resection surgery. The first line of treatment included initial doublet chemotherapy combined with trastuzumab, which was continued later as maintenance. PET-CT follow-up for 4 years has demonstrated no evidence of disease. However, upon recurrence, use of Ado-trastuzumab emtansine was prompted as second-line of treatment. This targeted patient-tailored therapy has accomplished a complete response. The effectiveness of ado-trastuzumab emtansine was notable within a short time period of two treatment cycles leading to full recovery. Specific agents aimed at altered oncogenes should be considered as a potential drug of choice in neoadjuvant HER2 positive SDC.

Anticancer Effects of Sublingual Type I IFN in Combination with Chemotherapy in Implantable and Spontaneous Tumor Models

Salivary gland tumors are a heterogeneous group of neoplasms representing less than 10% of all head and neck tumors. Among salivary gland tumors, salivary duct carcinoma (SDC) is a rare, but highly aggressive malignant tumor resembling ductal breast carcinoma. Sublingual treatments are promising for SDC due to the induction of both local and systemic biological effects and to reduced systemic toxicity compared to other administration routes. In the present study, we first established that the sublingual administration of type I IFN (IFN-I) is safe and feasible, and exerts antitumor effects both as monotherapy and in combination with chemotherapy in transplantable tumor models, i.e., B16-OVA melanoma and EG.7-OVA lymphoma. Subsequently, we proved that sublingual IFN-I in combination with cyclophosphamide (CTX) induces a long-lasting reduction of tumor mass in NeuT transgenic mice that spontaneously develop SDC. Most importantly, tumor shrinkage in NeuT transgenic micewas accompanied by the emergence of tumor-specific cellular immune responses both in the blood and in the tumor tissue. Altogether, these results provide evidence that sublingual IFN holds promise in combination with chemotherapy for the treatment of cancer.

Prognostic Implication of Histopathologic Indicators in Salivary Duct Carcinoma: Proposal of a Novel Histologic Risk Stratification Model

Salivary duct carcinoma (SDC) is a rare, aggressive malignancy that histologically resembles high-grade mammary duct carcinoma. Because of the rarity of this entity, data verifying the association between histologic features and patient survival are limited. We conducted a comprehensive histologic review of 151 SDC cases and performed an analysis of the association between various histomorphologic parameters and the clinical outcome with the aim of developing a histologic risk stratification model that predicts the prognosis of SDC patients. A multivariate analysis revealed that prominent nuclear pleomorphism (overall survival [OS]: P=0.013; progression-free survival [PFS]: P=0.019), ≥30 mitoses/10 HPF (PFS: P=0.013), high tumor budding (OS: P=0.011; PFS: P<0.001), and high poorly differentiated clusters (OS: P<0.001; PFS: P<0.001) were independent prognostic factors. Patients with vascular invasion demonstrated a marginally significant association with shorter PFS (P=0.064) in a multivariate analysis. We proposed a 3-tier histologic risk stratification model based on the total number of positive factors among 4 prognostically relevant parameters (prominent nuclear pleomorphism, ≥30 mitoses/10 HPF, vascular invasion, and high poorly differentiated clusters). The OS and PFS of patients with low-risk (0 to 1 point) (23% of cases), intermediate-risk (2 to 3 points) (54% of cases), and high-risk (4 points) (23% of cases) tumors progressively deteriorated in this order (hazard ratio, 2.13 and 2.28, and 4.99 and 4.50, respectively; Ptrend<0.001). Our histologic risk stratification model could effectively predict patient survival and may be a useful aid to guide clinical decision-making in relation to the management of patients with SDC.

Bone marrow metastases in salivary duct carcinoma of the parotid gland

Salivary duct carcinoma (SDC) is a rare and extremely aggressive salivary gland cancer. An 81-year-old woman with SDC underwent a total parotidectomy with facial nerve sacrifice and a neck dissection. Following surgery, she was diagnosed with disseminated bone marrow metastases. She underwent chemotherapy and trastuzumab for palliation. We present a case of SDC of the parotid which was diagnosed with disseminated bone marrow metastasis following surgery for the primary. This case also highlights the importance of having a high index of suspicion while evaluating highly aggressive tumours like SDC for any atypical findings during workup.

Expression of PTEN, Androgen Receptor, HER2/neu, Cytokeratin 5/6, Estrogen Receptor-Beta, HMGA2, and PLAG1 in Salivary Duct Carcinoma

Salivary duct carcinoma (SDC) is an aggressive neoplasm that resembles high-grade invasive ductal carcinoma of the breast. It can develop de novo or from the malignant transformation of pleomorphic adenoma (PA). We performed immunohistochemical stains for phosphatase and tensin homologue [PTEN androgen receptor (AR)], HER2/neu, cytokeratin 5/6, estrogen receptor-beta, high-mobility group AT-hook 2 (HMGA2), and pleomorphic adenoma gene 1 (PLAG1) on tissue microarray samples of 75 SDCs and 31 adenocarcinomas, not otherwise specified (NOS). Our data showed the following in SDC samples: loss of PTEN was found in 17 of 60 (28.3%); AR was expressed in 43 of 62 (69.4%); HER2/neu was overexpressed in 25 of 58 (43.1%); cytokeratin 5/6 was expressed in 14 of 54 (25.9%); estrogen receptor-beta was expressed in 37 of 56 (66.1%); HMGA2 was expressed in 29 of 63 (46.0%); and PLAG1 was expressed in 0 of 62 (0%). In addition, there was no statistically significant difference in the age at onset between patients with HMGA2-positive SDCs (range 32-85 years; mean: 64.3 years; median: 64.5 years) and those with HMGA2-negative SDCs (range 41-79 years; mean: 62.5 years; median: 64.5 years). There was also no statistically significant difference in overall survival between patients with HMGA2-positive and HMGA2-negative SDCs (follow-up period range 3-201 months; mean: 49.8 months; median: 30 months). Among 10 patients with a definite PA component (SDC ex-PA), 6 were positive and 4 were negative for HMGA2. Our data were consistent with previous findings that AR and estrogen receptor-beta are expressed in most SDCs, whereas HER2/neu overexpression and loss of PTEN are expressed in a subset of SDCs. In our cohort of patients, HMGA2 was expressed in approximately half of SDCs. HMGA2 and PTEN are promising therapeutic targets for salivary gland tumors.

Biomarker immunoprofile in salivary duct carcinomas: clinicopathological and prognostic implications with evaluation of the revised classification

Salivary duct carcinoma (SDC) is an uncommon, aggressive malignant neoplasm histologically resembling high-grade mammary ductal carcinoma. SDC can arise de novo or ex pleomorphic adenoma. To clarify the correlation of biomarker immunoprofile with clinicopathological findings and clinical outcome of SDC, we conducted immunohistochemistry for EGFR, HER2, HER3, AR, CK5/6, p53, and Ki-67, along with HER2 fluorescence in situ hybridization in 151 SDCs. SDCs ex pleomorphic adenoma more commonly overexpressed EGFR, HER2, HER3, and Ki-67 than de novo SDCs (P = 0.015, < 0.001, 0.045, and 0.02, respectively). In multivariate analysis, AR− and CK5/6+ were associated with shorter progression-free survival (P = 0.027 and 0.004, respectively). Moreover, patients with p53-extreme negative/positive demonstrated poorer overall survival (P = 0.007). On assessing the revised classification by the combination of biomarker expression, the percentages of each subtype were as follows: ‘apocrine A’ (AR+/HER2−/Ki-67-low) (24%), ‘apocrine B’ (AR+/HER2−/Ki-67-high) (18%), ‘apocrine HER2’ (AR+/HER2+) (35%), ‘HER2-enriched’ (AR−/HER2+) (12%), and ‘double negative’ (AR−/HER2−) (11%). ‘Double negative’ was further subclassified into ‘basal-like’ (EGFR and/or CK5/6+) (7%) and ‘unclassified’ (3%). Consequently, patients with ‘apocrine A’ showed a better progression-free survival than those with any other subtypes. Our revised immunoprofiling classification was valuable for predicting the survival and might be useful in personalized therapy for patients with SDC.

A 20-Year Review of 75 Cases of Salivary Duct Carcinoma

IMPORTANCE

Salivary duct carcinoma is a rare, aggressive malignancy of the salivary glands. Owing to its rare nature, clinical data are limited, and only a few clinical studies comprise more than 50 patients.

OBJECTIVE

To review the University of Pittsburgh Medical Center's experience with salivary duct carcinoma over a 20-year period, focusing on demographics, presentation, treatment, and outcome.

DESIGN, SETTING, AND PARTICIPANTS

This investigation was a retrospective cohort study in a multihospital institution with tertiary referral. A pathology database was reviewed for all cases of histopathologically diagnosed salivary duct carcinoma from January 1, 1995, to October 20, 2014. Patients who were referrals for pathology review only and were never seen at the institution were excluded. In total, 75 study patients were identified. The electronic medical record was reviewed for details regarding demographics, presentation, treatment, and outcome, including overall survival (OS) and disease-free survival (DFS). This study was supplemented with a review of the institution's Head and Neck Oncology Database for further clinical details.

MAIN OUTCOMES AND MEASURES

Primary outcome measures consisted of OS and DFS.

RESULTS

The study sample comprised 75 participants with a mean age at diagnosis of 66.0 years (age range, 33-93 years), and 29% (n = 22) were female. Most primary tumors were from the parotid gland (83%), with the next most frequent site being the submandibular gland (12%). Overall, 41% of the cases were carcinoma ex pleomorphic adenoma. Rates of other histologic features included the following: perineural invasion (69%), extracapsular spread (58%), ERBB2 (formerly HER2) positivity (31%) (62% of those who were tested), and vascular invasion (61%). The median OS was 3.1 years, and the median DFS was 2.7 years. Univariate Kaplan-Meier survival analyses demonstrated that facial nerve sacrifice and extracapsular spread were associated with lower OS (2.38 vs 5.11 years and 2.29 vs 6.56 years, respectively) and DFS (2.4 vs 3.88 years and 1.44 vs 4.5 years, respectively). Although underpowered, multivariable analysis demonstrated significantly worse OS in patients with N2 and N3 disease (hazard ratio [HR] 8.42, 95% CI, 1.84-38.5) but did not show significantly worse DFS or OS for facial nerve sacrifice or extracapsular spread. There was no association between ERBB2 positivity and survival and no difference in survival between patients receiving radiation therapy vs radiation therapy plus chemotherapy. No patients had recurrence or distant metastasis after 5 disease-free years.

CONCLUSIONS AND RELEVANCE

Salivary duct carcinoma is an aggressive disease. A large number of cases in this review were carcinoma ex pleomorphic adenoma and had classic negative prognostic indicators, such as perineural invasion, vascular invasion, and extracapsular spread. ERBB2 positivity was not associated with any difference in survival. Facial nerve involvement appears to indicate worse prognosis, as does nodal stage higher than N1. Recurrence and metastasis after 5 years are rare.

Correlation of Histopathological Variants, Cellular DNA Content, and Clinical Outcome in Adenoid Cystic Carcinoma of the Salivary Glands

OBJECTIVE: To study the correlation between flow cytometrically measured DNA ploidy with prognostically important histopathologic groups and clinical outcome in patients with adenoid cystic carcinoma of the salivary glands.

STUDY DESIGN: 46 tumor specimens were analyzed flow cytometrically for DNA content and assessed for histological grade. Correlations were made between tumor DNA ploidy and histopathological grade, and disease-free and overall survival of these patients.

RESULTS: Of the 46 patients, 31 had a cribiform/tubular histologic pattern, and 15 had a solid pattern. 84% of the tumors with cribriform/tubular pattern were DNA diploid, compared with 33% of tumors that were graded solid. This difference proved to be statistically significant (χ 2 11.75, P = 0.0006). Overall and disease-free survival periods were longer for patients with DNA diploid tumors in both groups, 63% vs. 36% and 62% vs 38%, respectively.

CONCLUSIONS: Tumor DNA ploidy correlates with prognostically important tumor histopathology as well as overall and disease-free survival in patients with adenoid cystic carcinoma of the salivary gland. EBM rating: B-3.

Salivary duct carcinoma: a Danish national study

BACKGROUND

To present the first national series of salivary duct carcinoma patients, including survival rates and an analysis of prognostic factors.

METHODS

By merging three Danish nationwide registries that encompass an entire population, 34 patients diagnosed with salivary duct carcinoma from 1990 to 2005 were identified. Histological slides were reviewed, and data concerning demographics, tumour site, clinical stage, treatment profiles and follow-up were retrieved. Survival estimates and prognostic factors were evaluated by comparing Kaplan-Meier plots using the Mantel-Haenszel log-rank test.

RESULTS

Salivary duct carcinoma showed an incidence of 0.04/100.000 inhabitants/year. Distant recurrence was seen in 52% of patients. Five-year overall survival, disease-specific survival and recurrence-free survival were 32%, 42% and 35%, respectively. Univariate analyses suggested that overall stage (III/IV) and vascular invasion have a negative impact on all survival measures. Involved resection margins correlated with a poorer overall survival and disease-specific survival, whereas adjuvant radiotherapy improved overall survival and recurrence-free survival.

CONCLUSIONS

Salivary duct carcinoma incidence averages to two episodes per year in the entire Kingdom of Denmark. With half of patients in this study experiencing distant recurrences and only a third surviving at 5 years, prognosis is dismal. Advanced overall stage, vascular invasion and involved resection margins all seem to correlate with a poorer survival, while adjuvant radiotherapy significantly improved outcome. Extensive T-site surgery, neck dissection and adjuvant radiotherapy are therefore recommended.

Clinical Outcomes and Prognostic Factors for Salivary Duct Carcinoma: A Multi-Institutional Analysis of 141 Patients

BACKGROUND

Among salivary gland malignancies, the prognosis of salivary duct carcinoma (SDC) is assumed to be the poorest. However, because of its low incidence, reliable survival estimates and prognostic factors based on a large number of patients remain to be elucidated, thereby making it impossible to standardize the optimal treatment for SDC.

METHODS

We performed this multi-institutional, retrospective analysis by collecting the clinical information of 141 patients with SDC without distant metastasis who underwent curative surgery as the initial treatment to elucidate overall survival (OS) and disease-free survival (DFS) along with their prognostic factors.

RESULTS

The 3-year OS and DFS rates were 70.5 and 38.2 %, respectively. Multivariate analysis revealed that age ≥65 years (p < 0.001) and N1 and N2 (p = 0.047 and <0.001, respectively) were independent prognostic factors for OS, whereas the primary site of the minor salivary and sublingual gland (p < 0.001) and N2 (p < 0.001) were those for DFS. The most common treatment failure was distant metastasis (55 patients, 39.0 %). For early parotid SDC, neither total parotidectomy in the patients with early T stage nor nerve resection in the patients without facial nerve palsy showed survival benefits.

CONCLUSIONS

Advanced N stage independently affects both OS and DFS. Partial parotidectomy with facial nerve preservation could be a less invasive standard surgical procedure for parotid gland SDC in the early T stage without facial nerve palsy. Effective systemic therapy is imperative to improve DFS of SDC.

Salivary duct carcinoma in the mandibular anterior region: The role of immunohistochemical markers in its definitive diagnosis

Salivary duct carcinoma (SDC) is a high-grade adenocarcinoma arising from the ductal epithelium of salivary glands which rarely involves the minor salivary glands. The varied histological presentation in the minor salivary gland tumors makes them the most heterogeneous group of neoplasms, making the diagnosis a challenge. This report highlights the importance of immunohistochemical markers in the definitive diagnosis of SDC.

[Survival analysis and immunohistochemical study of HER-2 and AR (androgen receptor) expression in salivary duct carcinoma]

BACKGROUND

Because of its low incidence, the clinical characteristics of the salivary duct carcinoma (SDC) based on a statistical analysis with a large number of patients remain to be elucidated, and thus it has been impossible to standardize the optimal treatments of SDC including adjuvant systemic therapy.

AIMS

The present study aimed to determine the prognostic factors along with the clinical outcomes of patients with SDC and to evaluate the expression of several receptor molecules as treatment targets.

METHODS

We performed a statistical analysis and immunohistochemical examination of 16 patients with SDC who had undergone initial treatment in the Department of Otorhinolaryngology, Head and Neck Surgery, Keio University School of Medicine from 1996 to 2010.

RESULTS

The 3-year disease-free survival (DFS) and cause-specific survival (CSS) rates were 29.2% and 72.7%, respectively. At the time of the analysis, 6 patients are alive without the disease, 2 patients are alive with distant metastasis, whereas 7 patients had died of distant metastasis, and 1 patient had died of another cause (pulmonary embolism). We examined the prognostic value of the clinico-pathological factors such as age, sex, T classification, N classification, clinical stage, primary site, histological pre-existence of pleomorphic adenoma. A univariate analysis revealed that DFS was significantly correlated with age (p = 0.049), T classification (p = 0.018), and clinical stage (p = 0.029), whereas no factor was found to be correlated with CSS. A multivariate analysis demonstrated that age (> or = 61 vs. < or = 60, risk ratio (RR) = 5.423, p = 0.042) and T classification (3, 4 vs. 1, 2, RR = 1.087, p = 0.020) were the independent prognostic factors for DFS. Positive expressions of HER2, ER (estrogen receptor), PR (progesterone receptor), AR (androgen receptor), and MIB-1 (index > 20%) were found in 50%, 6%, 13%, 100%, and 69%, respectively. However, none of them showed significant correlation with survival.

CONCLUSION

Frequent expressions of HER-2 and AR in SDC suggest that these receptors can be suitable molecular targets of systemic therapy for patients with SDC in which distant metastasis seems to be the largest obstacle to improving survival. In order to assess the efficacy of anti-HER-2 therapy and anti-androgen therapy for each receptor-positive SDC, a multi-institutional joint research system should be organized.

Human epidermal receptor 2-amplified salivary duct carcinoma: regression with dual human epidermal receptor 2 inhibition and anti-vascular endothelial growth factor combination treatment

BACKGROUND

Salivary ductal carcinoma is a rare cancer with poor prognosis and limited treatment options. Human epidermal receptor 2 (HER2)-directed treatment has been attempted in HER2-amplified or overexpressed salivary gland malignancies with limited success.

METHODS

We report resolution of measurable disease and minimal residual disease in a patient with salivary duct cancer treated with trastuzumab, lapatinib, and bevacizumab, with treatment ongoing for more than 2 years.

RESULTS

This treatment has been tolerated well except for grade 2 diarrhea and mucositis, which required a dose reduction of lapatinib to 1000 mg daily. The response observed was achieved in spite of receiving extensive prior therapy, including trastuzumab and/or chemotherapy for 20 months on which his tumors progressed.

CONCLUSION

The combination of trastuzumab, lapatinib, and bevacizumab may warrant investigation as a non-cytotoxic alternative for treatment of HER2-amplified or overexpressed salivary duct carcinoma and other HER2-amplified or overexpressed salivary gland tumors, particularly those not responsive to trastuzumab monotherapy.

An immunohistochemical panel for reliable differentiation of salivary duct carcinoma and mucoepidermoid carcinoma

Salivary duct carcinoma is a highly aggressive salivary gland malignancy that may be misdiagnosed as high-grade mucoepidermoid carcinoma. We utilized tissue microarrays with 78 examples of mucoepidermoid carcinoma and 47 salivary duct carcinomas to evaluate the utility of an immunohistochemical panel consisting of androgen receptor, Her2/neu, p63, and cytokeratin 5/6 in distinguishing these entities. Among all cases in the cohorts, androgen receptor was highly specific for salivary duct carcinoma, while cytokeratin 5/6 and p63 were specific for mucoepidermoid carcinoma. While the rate of unequivocal Her2/neu overexpression among the salivary duct carcinomas was low (8.9 %), discrimination of salivary duct carcinoma was enhanced when this marker was used in combination with androgen receptor due to profound sensitivity. The immunohistochemical panel was particularly efficacious at distinguishing the problematic subset of high-grade mucoepidermoid carcinomas from salivary duct carcinoma. Utilization of this set of immunohistochemical markers allows reliable differentiation of salivary duct and mucoepidermoid carcinoma, a distinction with important prognostic and therapeutic implications.

Salivary duct carcinoma responding to trastuzumab-based therapy: case report and review of the literature

BACKGROUND

Salivary duct carcinoma (SDC) is a rare malignancy with a poor prognosis. Human epidermal growth factor receptor-2 (Her-2/neu) is overexpressed in SDC and, hence, HER-2/neu targeted therapy could be an option.

METHODS

A 72-year-old man presented with parotid swelling and cervical lymphadenopathy. He underwent a parotidectomy, modified radical neck dissection, and postoperative chemoradiation with cisplatin. A year later, he developed metastatic disease in the contralateral neck that was treated surgically with right axillary lymphadenopathy. He received radiation to both sites, concurrent with carboplatin. Two years later, he underwent resection of a lung metastasis. He then had progression in the axillary and mediastinal lymph nodes and received 5 cycles of docetaxel and trastuzumab followed by maintenance trastuzumab.

RESULTS

The patient had a partial response and restaging studies 9 months after therapy discontinuation did not show progression.

CONCLUSION

Trastuzumab-based therapy is a potential therapeutic option for patients with SDC.

HER-2/neu gene amplification in carcinoma ex pleomorphic adenoma in relation to progression and prognosis: a chromogenic in-situ hybridization study

AIMS

  The aim of this study was to investigate the potential role of HER-2/neu in the stepwise progression of carcinoma ex pleomorphic adenoma (CXPA) and to evaluate its prognostic significance in CXPA.

METHODS AND RESULTS

  We examined HER2 overexpression and HER2 amplification by immunohistochemistry and chromogenic in-situ hybridization in 31 cases of CXPA with ductal differentiation (eight intraductal, five intracapsular, and 18 extracapsular) and seven cases of atypical pleomorphic adenoma (PA). HER2 overexpression and HER2 amplification were found in 17 (54.8%) and 12 (38.7%) of the 31 CXPA cases, respectively. HER2 amplification was more prevalent in extracapsular CXPAs (9/18 cases; 50%) than intracapsular CXPAs (1/5 cases; 20%), intraductal CXPAs (2/8 cases; 25%), or atypical PAs (0/7 case; 0%). The status of HER2 amplification was essentially retained from the intraductal to the extracapsular component in individual extracapsular CXPAs. In addition, HER2 amplification was significantly associated with a worse prognosis (shorter disease-free survival time and shorter overall survival time) among extracapsular CXPAs (each P < 0.05).

CONCLUSIONS

  These results suggest that HER2 may play an important role in the progression of CXPA, and that HER2 amplification may be an additional prognostic indicator of CXPA.

Management and outcome of salivary duct carcinoma in major salivary glands

Salivary duct carcinoma (SDC) is a rare and aggressive malignancy with poor prognosis. Its histomorphology is distinctly reminiscent of the ductal carcinoma of the breast. We reviewed the treatment and outcome of SDCs at a single tertiary care centre. Twenty-five cases of SDC of major salivary gland origin, diagnosed and treated at the Department of Otolaryngology, Head and Neck Surgery, Helsinki University Central Hospital, Helsinki, Finland, during a 14-year period from 1997 to 2011, were reviewed retrospectively. Survival outcome was analyzed for 18 patients with a minimum follow-up of 24 months. There were 16 male (64 %) and 9 female (36 %) patients with a median age of 61 years (range 36-82 years). The majority of the cases occurred in the parotid gland (n = 21, 84 %) followed by the submandibular gland (n = 4, 16 %). The primary treatment consisted of surgical resection in all cases and 17 (68 %) patients also underwent neck dissection. Most of the patients (n = 18, 72 %) were treated with postoperative radiotherapy. Seven patients (28 %) had a disease recurrence within a median follow-up time of 15 months (range 3-27 months). In the group (n = 18) with a minimum follow-up time of 24 months, the 2- and 5-year overall and disease-specific survival rates were 66, 41 % and 75, 55 %, respectively. These results confirm the aggressive nature of SDCs in major salivary glands. Diagnostics and management of these tumours need to be centralized in experienced surgical Head and Neck Oncology Centres, and new treatment strategies should be investigated.

Common Malignant Salivary Gland Epithelial Tumors

Malignant salivary gland epithelial tumors are histologically diverse with at least 24 recognized distinct entities. In general, malignant tumors account for 15% to 30% of parotid tumors, 40% to 45% of submandibular tumors, 70% to 90% of sublingual tumors, and 50% of minor salivary tumors. Common malignancies include mucoepidermoid carcinoma, adenoid cystic carcinoma, acinic cell carcinoma, salivary duct carcinoma, carcinoma ex pleomorphic adenoma, polymorphous lowgrade adenocarcinoma, and myoepithelial carcinoma. Each tumor type has its own unique histologic variants and prognostic pathologic features, and only mucoepidermoid carcinomas have a formalized grading system. The molecular pathogenesis of certain tumors, such as mucoepidermoid carcinoma and adenoid cystic carcinoma, has recently begun to be elucidated.

TRK-A, HER-2/neu, and KIT Expression/Activation Profiles in Salivary Gland Carcinoma

Salivary duct carcinomas (SDCs) and adenoid cystic carcinomas (ACCs) are the most aggressive and the most frequent carcinomas of the salivary glands, respectively. Little is known about them in terms of molecular/biochemical characterization and conventional treatments are ineffective. On cryopreserved material, we analyzed the expression/activation status of TRK-A, HER-2/neu, and KIT receptors by means of immunoprecipitation and Western blot analysis experiments, and the presence of their cognate ligands by means of Western blot analysis and/or reverse transcription-polymerase chain reaction in 9 SDCs, 12 ACCs, and 8 normal glands. The amplification status of HER-2/neu was also investigated by means of fluorescent in situ hybridization analysis on fixed material. The receptor tyrosine kinase (RTK)-deregulated profile of the SDCs was characterized by the overexpression of activated TRK-A in the presence of its ligand, and the overexpression of HER-2/neu sustained by gene amplification. The RTK signature of the ACCs was represented by the overexpression of activated KIT and TRK-A and their cognate ligands, and the overexpression of activated HER-2/neu, in the absence of gene amplification, possibly sustained by epidermal growth factor receptor heterodimerization. In conclusion, SDCs and ACCs, although sharing TRK-A autocrine loop activation, have different pathologically activated RTK-deregulated profiles that may be potential targets for pharmacological RTK inhibitors.

Inhibition of invasion and migration of salivary gland adenocarcinoma cells by 5'-nitro-indirubinoxime (5'-NIO)

BACKGROUND

5'-Nitro-indirubinoxime (5'-NIO) is a derivative of the bis-indole indirubin that exhibits anticancer activities. The present study investigated the anti-invasive action of 5'-NIO in salivary gland ductal adenocarcinoma, SGT cells.

METHODS

The wound-scratch, migration, and invasion assays were applied to determine the effect of 5'-NIO on the migration capacity and invasiveness of SGT cells. Reverse-transcriptase-polymerase chain reaction (RT-PCR) and Western blot were performed to evaluate the impacts of 5'-NIO on the expression of beta1 integrin and matrix metalloproteinases MMP-2 (gelatinase-A) and MMP-9 (gelatinase-B).

RESULTS

The viability of SGT cells was decreased by 5'-NIO in a dose-dependent manner, but not significant at the concentrations of 0.5 and 1 microM. Under the concentrations showing little cytotoxic effect, 5'-NIO exhibited a dose-dependent inhibitory effect on the invasion and migration of SGT cells. Furthermore, 5'-NIO suppressed the mRNA and protein expression of beta1 integrin and MMP-2 and MMP-9.

CONCLUSION

Taken together, these results suggest that 5'-NIO, even at low concentrations, may effectively inhibit the invasion and migration of SGT cells by suppressing beta1 integrin-mediated signaling.

Expression of mitotic checkpoint proteins BUB1B and MAD2L1 in salivary duct carcinomas

OBJECTIVE

Defects in the mitotic checkpoint lead to aneuploidy and might facilitate tumorigenesis. However, the ploidy status in salivary duct carcinoma (SDC) has been reported to play limited role in prediction of prognosis. Thus, we need more reliable markers to reflect the rapid tumor progression in SDCs. We aimed here to investigate the expression of mitotic checkpoint proteins benzimidazole 1 homolog beta (BUB1B) and mitosis arrest-deficient 2 like 1 (MAD2L1) in SDCs and to determine their possible role as surrogate prognostic markers.

METHODS

We analyzed the clinical courses, pathologic findings and immunohistochemical profiles of mitotic checkpoint proteins (BUB1B and MAD2L1) in 27 pathologically confirmed SDCs. The expression status of BUB1B and MAD2L1 was compared with clinicopathologic factors and other molecular markers, such as TGF-beta, c-erb-B2, androgen receptor, vascular endothelial growth factor, and epidermal growth factor receptor, for prognostic significance.

RESULTS

High BUB1B expression was detected in 25.9% of subjects, and high MAD2L1 expression was in 55.6% of subjects. However, survival analysis revealed that mitotic checkpoint expression did not have prognostic significance in SDCs, nor did the other studied markers. Rather, the clinical variable of N classification at diagnosis (in N+ status, hazard ratio 5.19, 95% CI 1.26-21.32 for disease-free survival and hazard ratio 7.18, 95% CI 1.09-46.99 for overall survival) was strongly associated with survival and prognosis based on the Cox proportional hazard model.

CONCLUSIONS

Mitotic checkpoint proteins appeared to play a limited role in predicting prognosis in SDCs. Further study is required to elucidate the exact role of mitotic checkpoint proteins in SDCs.

Overexpression of EGFR and absence of C-KIT expression correlate with poor prognosis in salivary gland carcinomas

AIMS

To evaluate the prognostic impact of expression of receptor tyrosine kinases epidermal growth factor receptor (EGFR), HER2, and C-KIT in relation to established clinicopathological parameters in salivary gland carcinomas.

METHODS AND RESULTS

Immunohistochemistry for EGFR, HER2, C-KIT and the proliferation marker Ki67 was performed in 101 cases of salivary gland carcinoma and related to long-term clinical follow-up. Immunopositivity of C-KIT was common in adenoid cystic carcinoma (92%). Lack of C-KIT expression occurred in salivary duct carcinoma (P < 0.001) and was associated with high-grade tumours (P = 0.002), positive lymph nodes (P = 0.002) and high expression of Ki67 (P = 0.001). HER2 was typically expressed in salivary duct carcinomas (83%), but was not associated with any other parameter. EGFR overexpression occurred independently of histological type and clinical parameters. On univariate survival analysis, overexpression of EGFR (P = 0.011) and lack of C-KIT (P = 0.014) were associated with worse prognosis, whereas HER2 was of no prognostic significance. On multivariate analysis, the strongest negative predictor of survival was high proliferative activity measured by Ki67 (P = 0.002), followed by presence of residual tumour (P = 0.006), overexpression of EGFR (P = 0.026) and advanced tumour stage (P = 0.041).

CONCLUSIONS

The expression of receptor tyrosine kinases confers additional prognostic impact on disease-specific survival. EGFR overexpression is an independent negative prognostic factor.

Immunohistochemical evaluation of androgen receptor, HER-2/neu, and p53 in benign pleomorphic adenomas

CONTEXT

Immunohistochemical stains for androgen receptor (AR), HER-2/neu, and p53 are used as diagnostic markers associated with malignancy in several histologic types of salivary gland tumors. These markers may be useful in differentiating pleomorphic adenoma with cytologic atypia from intracapsular carcinoma ex pleomorphic adenoma (CXPA), as these tumors are often difficult to distinguish on the basis of morphology alone.

OBJECTIVE

To determine whether AR, HER-2/neu, and p53 expression can be seen in entirely benign pleomorphic adenomas.

DESIGN

Androgen receptor, HER-2/neu, and p53 immunoreactivity was assessed in 41 histologically and clinically benign pleomorphic adenomas.

RESULTS

A total of 3 of 41 pleomorphic adenomas exhibited multifocal areas with moderate staining for HER-2/ neu and AR. The positive staining was mainly confined to the epithelial component, where the ductal epithelium showed no cytologic atypia. Immunoreactivity for p53 was observed in the epithelial component of 5 of 41 cases, none of which stained for HER-2/neu and AR. Mean mitotic rate and Ki-67 index were 1 per 10 high-powered fields and 2.7% in HER-2/neu- and AR-positive cases and 1 per 10 high-powered fields and 2.2% in p53-positive cases.

CONCLUSIONS

HER-2/neu, AR, and p53 are expressed in a subset of histologically and clinically benign pleomorphic adenomas. These markers cannot be used to reliably predict early carcinomatous transformation in pleomorphic adenoma.

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.

Prognostic values of pathologic findings and hypoxia markers in 21 patients with salivary duct carcinoma

BACKGROUND

Salivary duct carcinoma (SDC) is associated with aggressive clinical behavior.

METHODS

We examined the prognostic values of clinicopathologic variables and hypoxia biomarker expression in 21 patients with SDC treated by resection with/without neck dissection and radiotherapy. Tissue microarrays constructed from tumor blocks were stained with monoclonal antibodies to hypoxia-inducible factor (HIF)-1alpha, HIF-2alpha, carbonic anhydrase-9, glucose transporter-1, and erythropoietin receptor. Locoregional control and survival rates were calculated by the Kaplan-Meier method and prognostic factors were calculated from uni- and multivariate analyses.

RESULTS

The cervical nodal metastasis rate was 67% at initial diagnosis and the distant metastasis rate was 71% during follow-up. The only significant predictor of distant metastasis was nodal metastasis (P = 0.006). Actuarial 5-year locoregional control, distant metastasis-free survival, and overall survival rates were 57%, 40%, and 44%. Multivariate analysis showed that lymphovascular and perineural invasion and radiotherapy were independent predictors of overall survival (P < 0.025). None of the hypoxia biomarkers, however, was a significant predictor of locoregional control, distant metastasis, or survival.

CONCLUSIONS

Lymphovascular and perineural invasion, but not hypoxia biomarkers, were significant prognostic factors for patients with SDC.

Biological therapy of salivary duct carcinoma

BACKGROUND

The incidence of human epidermal growth factor receptor 2 positivity in salivary duct carcinoma ranges from 25 to 100 per cent and is associated with a poor outcome. Salivary duct carcinoma has significant pathological similarities to ductal carcinoma of the breast.

METHODS AND RESULTS

A 49-year-old man developed lung and liver metastasis a few months after surgery and adjuvant radiotherapy for salivary duct carcinoma of the parotid gland. There was no response to palliative chemotherapy with doxorubicin. We followed the biological model of breast cancer, whereby two-thirds of human epidermal growth factor receptor 2 positive patients respond to a combination of docetaxel and human epidermal growth factor receptor 2 blocker (trastuzumab). A durable, complete response was achieved with this combination. A rationalised treatment approach targeting the biological characteristics of salivary duct carcinoma had proven successful.

Her-2/neu expression in salivary duct carcinoma: an immunohistochemical and chromogenic in situ hybridization study

Salivary duct carcinoma (SDC) shares significant morphologic and immunophenotypic overlap with ductal carcinoma of the breast, including HER-2/neu expression. Previous studies have detected HER-2/neu at the protein level in SDCs; however, no study, to date, has assayed whether this expression is related to gene amplification detected by chromogenic in situ hybridization (CISH). Formalin-fixed, paraffin-embedded tissue sections from 12 previously diagnosed SDCs were evaluated by immunohistochemistry (IHC) and CISH for HER-2/neu status. Result concordance was seen in all 12 cases. A total of 4 SDCs were positive by IHC; all 4 cases showed amplification with CISH. The remaining 8 cases were negative by IHC and showed no gene amplification with CISH. SDCs in this study show HER-2/neu overexpression on both the protein and gene levels in approximately 30% of cases. These findings suggest a role may exist for Herceptin (trastuzumab) based therapy in some SDC 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.

Recent advances in the treatment of salivary gland cancers: emphasis on molecular targeted therapy

Salivary gland cancers include tumors of different histologic characteristics and biological behavior. Radical surgery, followed or not by radiation therapy, represents the main treatment approach for this disease. The role of systemic chemotherapy is less clearly defined since trials of single-agent chemotherapy have consistently shown low response rates. Polychemotherapy is likely to induce a higher response rate, but does not improve survival. The determination of the molecular abnormalities underlying the different subtypes of salivary gland cancers might lead to more active targeted therapies. C-kit is overexpressed in a wide percentage of salivary gland carcinomas, but clinical trials with single-agent imatinib have been negative. ErbB1 and ErbB2 are also frequently overexpressed in salivary gland cancers and this has provided the rationale for clinical trials with trastuzumab, cetuximab, gefitinib, lapatinib. Finally, new pathways, such as vascular endothelial growth factor, might be worth targeting and clinical trials with anti-angiogenic agents are ongoing.

Clinical and immunohistologic typing of salivary duct carcinoma: a report of 50 cases

BACKGROUND

Due to the low incidence of salivary duct carcinoma (SDC), only limited data in regard to the biologic behavior of this tumor and its immunohistochemical characteristics are available. The authors analyzed the clinical, molecular, and genetic profile of SDC and identified prognostic factors.

METHODS

The follow-up of 50 patients with SDC was obtained and paraffin-embedded tumor samples were examined immunohistochemically. In all samples, the expression of Ki-67, HER-2, and the oncoproteins p16 and p53 was examined immunohistochemically, followed by a mutation analysis of p16 and p53. The survival rate was calculated by the Kaplan-Meier method and prognostic variables were analyzed with the log-rank test.

RESULTS

SDC predominantly effected male patients (66%) in their 7th decade of life. SDC mainly occurred in the parotid gland (78%; submandibular gland, 12%; minor salivary glands, 10%). Approximately two-thirds of the patients (33 of 50) presented with a T3/T4 tumor. In 28 patients (56%), cervical lymph node metastasis was present at the time of diagnosis. Local disease recurrence was observed in 48% of patients an average of 17.4 months after initial treatment. Distant disease metastasis developed in 48% of patients an average of 29 months after initial treatment. The average overall survival period was 56.2 months. In the current study, 20.6% of the probes with positive HER-2/neu expression were (+++) positive. p53 was expressed in 83.9% of the tumor samples. In 11.8% of the tumor samples, there was a lack of p16 expression.

CONCLUSIONS

Mutations of the p53 gene were more frequent in tumor samples with (++) and (+++) immunoreactivity and mainly affected exons 7 and 8. A mutation of the p16 gene was only found in 1 tumor sample. Expression of HER-2/neu and p53 was statistically linked (P < 0.05) to early local disease recurrence, distant disease metastasis, and survival rates.

Novel estrogen receptor coactivator PELP1/MNAR gene and ERβ expression in salivary duct adenocarcinoma: potential therapeutic targets

Salivary duct carcinoma (SDC) is a high-grade neoplasm with marked morphological resemblance to mammary duct carcinoma. The novel estrogen receptor (ER)-interacting protein and the proline-, glutamic acid-, and leucine-rich protein 1 ( PELP1 ), also called the modulator of nongenomic activity of ER ( MNAR ), have been shown to activate steroid hormone receptors in mammary carcinomas by nongenomic and genomic mechanisms. The expression and the relationship of this gene to the ER status in SDCs are unknown. We investigated the differential expression of the PELP1 / MNAR and the ERs alpha and beta proteins in SDCs, using Western blotting and immunohistochemistry. Western blot analysis of 7 paired normal and tumor specimens showed increased expression of PELP1 / MNAR and ER beta in 3 and 4 of the SDCs, respectively. No detectable expression of ER alpha in any normal or SDC specimens was noted. Immunohistochemical staining performed on 70 SDCs revealed strong expression of PELP1 / MNAR in 51 (73%) and ER beta in 52 (74%) tumors. PELP1 / MNAR and ER beta were coexpressed in 35 (50%), individually in 17 (24.2%), and negative in 18 (25.7%) tumors. PELP1 / MNAR staining was predominantly cytoplasmic whereas ER beta staining was nuclear and occasionally cytoplasmic in tumor cells. Our results indicate that PELP1 / MNAR and ER beta are coexpressed in most SDCs and may play a role in the pathobiology of these tumors.

Non-invasive (intracapsular) carcinoma ex pleomorphic adenoma: recognition of focal carcinoma by HER-2/neu and MIB1 immunohistochemistry

AIMS

Non-invasive carcinoma ex pleomorphic adenoma is defined as a carcinoma arising within the boundaries of a pleomorphic adenoma (PA), but which fails to display invasion beyond the capsule of host PA. Alternative names are intracapsular, in situ, or focal carcinoma. The true nature of non-invasive carcinoma ex-PA is still controversial; for example, it is not clear whether it represents early but genuine carcinomatous changes with the genetic make-up of malignant cells, or simply cytological, possibly metaplastic or 'bizarre' changes in PA. Strong overexpression and amplification of HER-2/neu protein has recently been demonstrated in invasive carcinoma ex-PA. In addition, data from breast cancer studies suggest that amplification of HER-2/neu and overexpression of its gene product is mainly involved in the initiation of breast oncogenesis. We sought to establish whether this method could help to demonstrate that what is described as non-invasive carcinoma ex-PA is really a genuine malignancy, albeit in an early phase.

METHODS AND RESULTS

Eleven cases of non-invasive carcinoma (in situ) ex-PA were studied for HER-2/neu status using immunohistochemistry and fluorescent in-situ hybridization (FISH). Cells of focal non-invasive carcinoma ex-PA were strongly positive for HER-2/neu protein, while the cells of the maternal PA were always negative. Two cases of low-grade non-invasive myoepithelial carcinoma ex-PA were negative. In four cases out of a total of six tumours studied by FISH, we detected amplification of HER-2/neu gene signals in tumour cells of focal, non-invasive, carcinoma.

CONCLUSIONS

The current data suggest that non-invasive carcinoma ex PA is a genuine carcinoma within a PA. However, the presence of cyto-nuclear atypia is not sufficient to make a definite diagnosis of malignant change, which requires a combination of morphology and immunohistochemistry.

[Salivary duct carcinoma of the submandibular gland]

BACKGROUND

Salivary duct carcinoma (SDC) is a rare adenocarcinoma of the salivary glands which usually occurs in the parotid gland (approx. 80%), but is also found in the submandibular gland (approx. 12%) and the minor salivary glands. Due to the low incidence of this tumour-particularly in terms of involvement of the submandibular and minor salivary glands-only limited clinical data is available.

PATIENTS/METHOD

In a retrospective investigation, follow-ups of six patients with a SDC of the submandibular gland were analysed and the surgical measures evaluated for their efficiency.

RESULTS

At the time of diagnosis, varying tumor stages were present (2xT1, 3xT2, 1xT1). Initial lymph node metastasis was observed in four (66.6%) of the six patients. In all patients, the submandibular gland was resected and neck dissection performed, in two cases (33,3%) this was followed by radiotherapy. Four patients developed a life-threatening local recurrence. Only one patient developed distant metastasis. Two thirds of the patients died due to tumor-related disease after an average of 35.5 months.

CONCLUSION

The clinical course of patients with SDC of the submandibular gland exhibits a high (66.6%) rate of local recurrence, crucial for the following clinical course. The treatment of these patients, therefore, must include radical tumor resection as well as tissue resection with a wide margin.

Prognostic relevance of cell proliferation in head and neck tumors

Cell proliferative activity has been extensively investigated in head and neck tumors. Ki67/MIB-1 immunostaining, tritiated thymidine or bromodeoxyuridine labeling indices, DNA S-phase fraction, proliferating cell nuclear antigen expression, potential doubling time and analysis of the nucleolar organizer region associated proteins (AgNORs) have shown significant correlation with prognosis in 4806 cases of tumors of the oral cavity, salivary glands, pharynx and larynx. However, this was not observed in 2968 other reported cases. Discrepancies may depend on various factors: the heterogeneity of the series, which include tumors from various anatomic sites and patients treated with different therapy, and the lack of standardization of methods for assessing cell proliferation. Furthermore, none of the methods currently applied can by themselves define the actual proliferative activity, as it depends both on the proportion of cells committed to the cycle (growth fraction) and the speed of the cell cycle. Indeed, the actual proliferative activity of a tumor could well be measured by the equation [PA = Ki67 or MIB-1 scores x AgNORs], as we did in pharyngeal carcinoma. Provided that large and homogeneous series are evaluated by standardized methods, cell proliferative activity can still be regarded as an inexpensive and reliable prognostic factor in head and neck tumors.

Invasive micropapillary salivary duct carcinoma: a distinct histologic variant with biologic significance

An invasive micropapillary component has been described in tumors of several organs and is nearly always associated with aggressive biologic behavior. We present 14 cases of salivary duct carcinoma (SDC) with an invasive micropapillary component (invasive micropapillary SDC) and compare the clinicopathologic findings of these cases with those of cases of conventional SDC. The mean age of the 14 patients (10 men, 4 women) was 65.8 years (range, 26-80 years). The mean size of the tumors was 2.4 cm (range, 1.3-5 cm). The parotid gland was involved in 12 patients and the submandibular gland in 2. Histologically, all tumors had an invasive micropapillary architecture admixed with features typical for SDC. Invasive micropapillary carcinoma was characterized by morula-like small cell clusters without fibrovascular cores, surrounded by a clear space. Tumor cells exhibited moderate- to high-grade nuclear features, conspicuous nucleoli, and eosinophilic cytoplasm. This component was distributed diffusely in 9 tumors and focally in 5. Angiolymphatic and perineural invasion was seen in all tumors. A residual pleomorphic adenoma was detected in four tumors. Of the 12 tumors examined, all were diffusely positive for cytokeratin 7 and epithelial membrane antigen (with a distinctive "inside-out" pattern) but negative for cytokeratin 20. Tumors were frequently immunoreactive for BRST-2 (gross cystic disease fluid protein-15) and androgen receptor protein. Aberrant expression of HER-2/neu or p53 was detected in seven tumors each. The mean Ki-67 labeling index was 33.1% (range, 6.3%-61.6%). All 14 patients with invasive micropapillary SDC had cervical or periglandular lymph node metastasis, and this value was significantly higher than for conventional SDCs. Local recurrence developed in 4 patients and distant metastatic disease in 9. Clinical follow-up (mean, 25.5 months) was available for 13 patients: 9 died of disease within 24 months after the diagnosis (mean, 17.6 months), 1 was alive with metastatic disease at 19 months, and 3 were free of disease. Overall survival of these patients with invasive micropapillary SDC was significantly shorter than that of patients with conventional SDC (n = 49) in our series (P = 0.031). Our results suggest that invasive micropapillary SDC is a distinct, aggressive variant of SDC, with a propensity for extensive lymph node metastasis and rapid disease progression.

Salivary duct carcinoma: immunohistochemical profile of an aggressive salivary gland tumour

BACKGROUND

Salivary duct carcinoma (SDC) is considered to be a distinct malignancy of the major salivary glands, because of its highly aggressive behaviour, and the high rate of recurrence, metastasis, and disease related death.

AIMS

To investigate expression of the proteins involved in the retinoblastoma (pRb) and p53 pathways, which control cell cycle progression at the G1/S checkpoint, and also expression of the c-erbB-2 oncoprotein in SDCs.

METHODS

Using a streptavidin-biotin method, five cases of SDC were evaluated immunohistochemically for the presence of cyclin D1, CDK4 (cyclin dependent kinase 4), p16 (CDK2A), pRb (retinoblastoma protein), E2F-1, p53, mdm2 (murine double minute 2), bcl-2, and the c-erbB-2 oncoprotein to determine whether there was a correlation between the expression of these proteins and patient outcome.

RESULTS

All of the cases showed deregulation of the pRb and p53 pathways. Of the five patients analysed, only the patient with longterm survival (10 years) was not positive for c-erbB-2 expression.

CONCLUSIONS

c-erbB-2 overexpression was associated with a poor prognosis. Aggressive behaviour, recurrence, and metastatic potential do not appear to be related to cell cycle deregulation, but seem to be associated with the c-erbB-2 oncoprotein, which is involved in matrix degradation and proteolitic activity, in addition to increases in vessel permeability, endothelial cell growth, proliferation, migration, and differentiation. There was a correlation between c-erbB-2 oncoprotein expression and aggressive behaviour in SDCs.

Salivary duct carcinoma with neuroendocrine features: Report of a case with cytological and immunohistochemical study

We report a salivary duct carcinoma (SDC) of parotid gland in a 75-year-old male. Initially, it was studied by fine-needle aspiration, which disclosed features of malignancy consistent with a high-grade carcinoma. Histologically, the tumor showed typical features of SDC, predominantly with a solid and apocrine pattern. The aggressive behavior of this tumor was documented by facial palsy and the presence of 12 regional lymph node metastases. Immunohistochemical study showed positivity for cytokeratins (AE1/AE3), cytokeratin 7, GCDFP-15, C-erbB-2, Mib-1, topoisomerase II alpha, p53, and androgen receptors. Diffuse positivity with chromogranin-A, synaptophysin, and Grimelius stains was also observed, suggesting endocrine features. Phosphotungstic acid hematoxylin, antimitochondrial antigen, progesterone and estrogen receptors, cytokeratin 20, and S-100 stains were negative. To our knowledge, this is the first case reported of SDC exhibiting neuroendocrine differentiation.

Mucin-rich variant of salivary duct carcinoma: a clinicopathologic and immunohistochemical study of four cases

Salivary duct carcinoma is a relatively uncommon aggressive neoplasm, typically found in the parotid glands of older men. The histologic appearance is that of an in situ and invasive high-grade adenocarcinoma, and it closely resembles ductal carcinoma of the breast. Several variants of the latter are very well known, but only papillary, sarcomatoid, and low-grade subtypes have so far been reported in salivary duct carcinoma. This study describes the clinicopathologic and immunohistochemical findings in four examples of an additional previously undescribed variant, rich in mucin. Each tumor showed areas of typical salivary duct carcinoma, but in addition there were lakes of epithelial mucin-containing malignant cells, i.e., mucinous (colloid) carcinoma. All four tumors expressed androgen receptors, cytokeratins, epithelial membrane antigen, gross cystic disease fluid protein-15, and carcinoembryonic antigen, but S-100 protein, other myoepithelial markers, and estrogen and progesterone receptors were negative. The mucin antigen profile showed positivity for MUC2, MUC5B, and MUC6 in all cases but only rare staining with MUC5AC and MUC7. Strong immunohistochemical overexpression of HER2/neu was demonstrated in one tumor, together with amplification by fluorescence in situ hybridization; another case was weakly positive with just one antiserum, but the remaining two tumors were completely negative. Small quantities of mucin have often been described in salivary duct carcinoma but not large extracellular mucinous lakes, which though prominent in the present series, were not as extensive as in mucinous adenocarcinoma. The relatively poor clinical outcome of the patients in our study mirrored that seen in usual-type salivary duct carcinoma and emphasizes the importance of differentiating mucin-rich salivary duct carcinoma from pure mucinous (colloid) adenocarcinoma, a tumor not fully defined, but possibly with a better prognosis.

Expression of HER-2/neu gene and protein in salivary duct carcinomas of parotid gland as revealed by fluorescence in-situ hybridization and immunohistochemistry

AIMS

Salivary duct carcinoma is a highly malignant salivary gland tumour with aggressive clinical behaviour, characterized by histological resemblance to invasive ductal carcinoma of the breast. Amplification of HER-2/neu oncogene and over-expression of its gene product have both prognostic and therapeutic implications in breast cancer. Recent report on salivary duct carcinomas for HER-2/neu using immunohistochemistry (IHC) has shown over-expression in most cases. However, correlation between IHC and molecular genetic analysis of HER-2/neu in salivary duct carcinoma has not yet been performed.

METHODS AND RESULTS

We have now evaluated 11 cases of salivary duct carcinomas for HER-2/neu status using IHC and fluorescent in-situ hybridization (FISH). To our knowledge, this is the first molecular genetic analysis of HER-2/neu in salivary duct carcinoma.

CONCLUSIONS

In immunohistochemistry, over-expression of HER-2/neu protein was identified as distinct membrane staining in most carcinoma cells in all our salivary duct carcinoma cases, while only four cases revealed an amplification of HER-2/neu gene by means of FISH analysis. Both amplified and non-amplified salivary duct carcinomas with strong immunohistochemical staining for HER-2/neu protein were associated with poor clinical outcome for the patients. Apparently, HER-2/neu protein over-expression could also be controlled by mechanisms other than gene amplification. In the group of salivary gland tumours other than salivary duct carcinoma, strong over-expression was detected only in three cases of carcinoma ex pleomorphic adenoma. Thus, over-expression of HER-2/neu protein is also a useful marker of malignant transformation in pleomorphic adenomas.

Salivary duct carcinoma: cytokeratin 14 as a marker of in-situ intraductal growth

AIMS

The aim of this study was to determine the immunoprofile of salivary duct carcinoma and to differentiate intraductal growth from invasive growth.

METHODS AND RESULTS

We applied a panel of antibodies (cytokeratins 7, 8, 13, 14, 19, vimentin and alpha-smooth muscle actin) in five cases of salivary duct carcinoma. This panel is currently used for identification of different components of salivary gland tumours in our laboratory. All tumour cells were positive for cytokeratins 7 and 8. Few neoplastic structures expressed cytokeratin 14 in cells surrounding tumour islands.

CONCLUSION

The finding of cytokeratin 14 was important to confirm the in-situ intraductal growth, which probably characterizes this low-grade neoplasm.