Salivary duct carcinoma. Part I. A clinicopathologic evaluation and DNA image analysis of 13 cases with review of the literature

Targeting human EGFR 2 (HER2) in salivary gland carcinoma

INTRODUCTION

Human epidermal growth factor receptor 2 (HER2) protein overexpression, gene amplification, and activating mutations have been identified in a subset of salivary gland carcinoma (SGC) histologies (HER2-positive), especially in salivary duct carcinoma, and represent an important therapeutic target.

AREAS COVERED

The evidence for targeting HER2 in the adjuvant setting is limited to small retrospective series. Conversely, there are prospective trials supporting the use of anti-HER2 therapy in patients with unresectable, recurrent, or metastatic HER2-positive SGC, including trastuzumab plus docetaxel, trastuzumab plus pertuzumab, trastuzumab-pkrb plus nanoxel, trastuzumab emtansine (T-DM1), and trastuzumab deruxtecan (T-Dxd).

EXPERT OPINION

HER2-targeting should be considered for patients with advanced HER2-positive SGC. There are no data to guide the selection of one anti-HER2 agent over another in the palliative setting. Trastuzumab plus docetaxel can be considered for patients with a high disease burden, while trastuzumab plus pertuzumab is a good option for patients with low disease burden or borderline performance status. T-DM1 or T-Dxd can be considered upon disease progression on trastuzumab-combination therapies, although these antibody-drug conjugates can also be used upfront. Future research should investigate predictive biomarkers, the combination of HER2 and androgen blockade, and the application of novel therapies from breast cancer.

Paraneoplastic cerebellar degeneration with anti-Yo antibodies and an associated submandibular gland tumor: a case report

Background

As a debilitating syndrome, paraneoplastic cerebellar degeneration (PCD) remains challenging to treat. Further, anti-Yo antibody (directed against human cerebellar degeneration-related protein 2) detection in patients with PCD is associated with unsatisfactory responses to existing therapies. Here, we present the case of a 60-year-old woman who developed PCD with anti-Yo antibodies and a submandibular gland tumor.

Case presentation

A 60-year-old woman presented with a 5-day history of unsteadiness of gait and inadequate coordination of her extremities, along with truncal instability. Although walking without aid was possible, dysmetria of all four limbs, trunk, and gait ataxia was observed. While routine biochemical and hematological examinations were normal, the patient’s blood was positive for anti-Yo antibodies. When the neurological symptoms deteriorated despite administration of intravenous methylprednisolone, fluorodeoxyglucose-positron emission tomography (FDG-PET) and computed tomography (CT) images with contrast enhancement were performed, which showed a tumor in the left submaxillary gland. She underwent total left submandibular gland resection, including the tumor; histological and immunohistochemical results revealed a salivary duct carcinoma. She was administered intravenous methylprednisolone, followed by 10 plasma exchange sessions, intravenous immunoglobulins, and cyclophosphamide therapy. Following treatment, her symptoms were not alleviated, even after the reduction of anti-Yo titers.

Conclusions

Although tumor detection was delayed, early tumor detection, diagnosis, and PCD treatment are essential because any delay can result in the progression of the disorder and irreversible neurological damage. Therefore, we recommend that the possibility of a salivary gland tumor should be considered, and whole-body dual-modality CT, including the head and neck, and FDG-PET should be performed at the earliest for patients with well-characterized paraneoplastic antibodies when conventional imaging fails to identify a tumor.

Salivary Gland Cancers

Salivary gland carcinomas are a rare and heterogenous group of cancers with varying underlying biology and clinical behavior. A quickly evolving body of data has advanced the understanding of these tumors, leading to effective therapeutics for several histologic subtypes. Biologically rational clinical trials have developed from an understanding of MYB and NOTCH signaling in adenoid cystic carcinoma. The recognition of androgen receptor signaling and HER2-targeted therapy has offered therapeutic options in non-ACC salivary cancers. The use of TRK inhibitors in salivary secretory carcinoma has led to exceptional responses. Immunotherapy is an exciting new therapeutic avenue that requires further exploration.

Increased ERBB2 Gene Copy Numbers Reveal a Subset of Salivary Duct Carcinomas with High Densities of Tumor Infiltrating Lymphocytes and PD-L1 Expression

Salivary duct carcinoma (SDC) commonly expresses androgen receptor (AR) and HER2, giving rise to treatment implications. SDC may also express programmed-death-ligand-1 (PD-L1), a predictive marker of response to checkpoint inhibitors. PD-L1 can be associated with genomic instability and high density of tumor infiltrating lymphocytes (TILs). Evaluation of HER2 immunohistochemistry (IHC) in SDC is not standardized, and relationships between ERBB2 copy numbers, PD-L1 expression and TILs in SDC are unknown. We evaluated 32 SDCs for HER2, AR and PD-L1 expression (IHC), ERBB2 status (FISH) and TILs (slide review). HER2 was scored with three different systems (breast, gastric, proposed salivary gland). PD-L1 was evaluated with the combined positive score. Most patients were older men, presenting at advanced clinical stage with nodal or distant metastases. During follow-up (mean 5 years, range 6 months to 21 years), 25 of the 32 patients (78%) died of SDC. We propose a HER2 IHC scoring system which accurately predicts underlying ERBB2 amplification or increased copy numbers in SDC. Most tumors had increased ERBB2 copy numbers (19/32 amplification, 6/32 aneusomy), a finding associated with higher TIL densities (p = 0.045) and PD-L1 expression (p = 0.025). Patients with TILs ≥ 40% had better prognoses (Log-Rank p = 0.013), with TILs being favorable prognosticators in univariate analysis (Hazard ratio: 0.18, p = 0.024). A subset of SDCs with increased ERBB2 copy numbers have higher TILs and PD-L1 expression. TILs ≥ 40% are associated with better prognosis.

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.

Intensity Modulated Radiotherapy (IMRT) With Carbon Ion Boost in the Multimodal Treatment of Salivary Duct Carcinoma

Background: To assess outcomes and treatment related toxicity following intensity-modulated radiotherapy (IMRT) and a Carbon Ion Radiotherapy (CIRT) boost for salivary duct carcinoma (SDC).

Methods: Twenty-eight consecutive patients with SDC who underwent a postoperative (82%) or definitive (18%) radiation therapy between 2010 and 2017 were assessed in this retrospective single-center analysis. CIRT boost was delivered with median 18 Gy(RBE) in 6 daily fractions, followed by an TomoTherapy^®-based IMRT (median 54 Gy in 27 daily fractions). Treatment-related acute toxicity was assessed according to CTCAE Version 4.

Results: Tumors were most commonly located in the major salivary glands (n = 25; 89%); 23 patients (82%) received previous surgery (R0: 30%; R1: 57%; R2: 4%; RX: 19%). Median follow-up was 30 months. Four patients (14%) experienced a local relapse and 3 (11%) developed locoregional recurrence. The two-year local control (LC) and locoregional control (LRC) was 96 and 93%, respectively. Median disease-free survival (DFS) was 27 months, metastasis-free survival (MFS) was 69 months, and overall survival (OS) was 93 months. Acute grade 3 toxicity occurred in 11 patients (mucositis, dermatitis, xerostomia; n = 2 each (7%) were the most common) and 2 osteonecroses of the mandibular (grade 3) occurred. No patients experienced grade ≥4 toxicities.

Conclusions: Multimodal therapy approaches with surgery followed by IMRT and CIRT boost for SDC leads to good local and locoregional disease control. However, the frequent occurrence of distant metastases limits the prognosis and requires optimization of adjuvant systemic therapies.

Outcomes and prognostic factors in parotid gland malignancies: A 10-year single center experience

OBJECTIVES

To describe a 10-year single center experience with parotid gland malignancies and to determine factors affecting outcomes.

STUDY DESIGN

Retrospective review.

METHODS

The institutional cancer registry was used to identify patients treated surgically for malignancies of the parotid gland between January 2005 and December 2014. Clinical and pathologic data were collected retrospectively from patient charts and analyzed for their association with overall survival (OS) and disease-free survival (DFS).

RESULTS

Two hundred patients were identified. Mean age at surgery was 57.8 years, and mean follow-up time was 52 months. One hundred two patients underwent total parotidectomy, while 77 underwent superficial parotidectomy, and 21 underwent deep lobe resection. Seventy patients (35%) required facial nerve (FN) sacrifice. Acinic cell carcinoma was the most common histologic type (22%), followed by mucoepidermoid carcinoma (21.5%) and adenoid cystic carcinoma (12.5%). Twenty-nine patients (14.5%) experienced recurrences, with mean time to recurrence of 23.6 months (range: 1-82 months). Five- and 10-year OS were 81% and 73%, respectively. Five- and 10-year DFS were 80% and 73%, respectively. In univariate analyses, age > 60, histologic type, positive margins, high grade, T-stage, node positivity, perineural invasion, and FN involvement were predictors of OS and DFS. In the multivariate analysis, histology, positive margins, node positivity, and FN involvement were independent predictors of OS and DFS.

CONCLUSIONS

Our single-center experience of 200 patients suggests that histology, positive margins, node positivity, and FN involvement are independently associated with outcomes in parotid malignancies.

LEVEL OF EVIDENCE

4.

Metastatic Salivary Ductal Carcinoma to the Mastoid Segment of the Facial Nerve

OBJECTIVE

To describe salivary ductal carcinoma (SDC) presenting as an isolated lesion of the mastoid segment of the facial nerve PATIENTS:: A 70-year-old man presenting with weakness of his right lower lip that progressed to complete facial paralysis over a span of 2 weeks.

MAIN OUTCOME MEASURES

Clinical case records, immunohistochemical analyses, and radiological analyses including magnetic resonance imaging and positron emission tomography-computed tomography.

RESULTS

Nodular enhancement along the mastoid segment of the facial nerve was identified without any mass within the parotid on magnetic resonance imaging or regional/distant disease on positron emission tomography-computed tomography. Pathologic analysis of tissue obtained from a right parotidectomy, neck dissection, and transmastoid resection of the vertical segment of the facial nerve revealed a benign parotid gland with malignant glands identified intra- and perineurally within the central aspect of the gland.

CONCLUSIONS

SDC is one of the most aggressive salivary malignancies and typically presents as a rapidly enlarging mass in the involved gland. Although SDC's clinical course is characterized by early metastasis, isolated neural invasion has not been reported in the absence of an identifiable primary tumor within the gland of origin. The present case illustrates the clinical history and treatment of the first case of a SDC presenting as an isolated facial nerve lesion from perineural spread.

A Case of Lacrimal Gland Ductal Carcinoma With Regional Lymph Node Metastasis

Ductal carcinoma of the lacrimal gland is a very rare and aggressive neoplasm, with clinical and histopathologic similarities to salivary ductal carcinoma. Of the 25 previously reported cases, 2 patients had metastases to local lymph nodes confirmed on pathologic examination. The authors now report the clinical presentation, histopathologic and immunohistochemical features, and the treatment of a third patient with lacrimal gland ductal carcinoma with spread to local lymph nodes. In contrast to ductal carcinoma, lymph node involvement has not been reported in the largest series of adenoid cystic carcinoma, a much more common lacrimal gland malignancy. This case highlights the need for possible lymph node surveillance in patients with lacrimal gland ductal carcinoma.

Targeted therapy with trastuzumab for epidermal growth factor receptor 2 (HER2)-positive advanced salivary duct carcinoma: A case report

Herein we report two cases of advanced and/or metastatic salivary duct carcinoma that relapsed after standard first-line chemotherapy. As overexpression of human epidermal growth factor receptor 2 (HER2) (3+) was observed by immunohistochemistry, the patients were treated with trastuzumab plus paclitaxel. One patient showed a complete response lasting over 2.5 years after the commencement of therapy; however, the other patient had no response to trastuzumab combined therapy. Dual fluorescence in situ hybridization was performed after the initiation of chemotherapy; the first case was positive for HER2 gene amplification, while the second case was negative. Our experiences suggest that therapy with HER2 blockers should be considered as options for treatment of HER2-positive salivary duct carcinoma. However, HER2 protein overexpression and gene amplification should be investigated further as therapeutic biomarkers.

Salivary duct carcinoma: Prospective multicenter study of 61 cases of the Réseau d'Expertise Français des Cancers ORL Rares

BACKGROUND

The purposes of this study were to describe the characteristics of a prospective multicenter series of patients with salivary duct carcinoma and to investigate prognostic factors.

METHODS

Patients included for salivary duct carcinoma between 2009 and 2016 in the Réseau d'Expertise Français des Cancers ORL Rares (REFCOR) database were selected. Immunohistochemical analyses were performed.

RESULTS

Sixty-one patients were included in this study. The primary site was the parotid gland in 90% of the cases. Fifty-seven percent of the tumors were stage IV, 65% of patients had lymph node involvement, and 10% had metastases. Tumors showed androgen receptor (89%) and human epidermal growth factor receptor 2 (HER2)/neu (36%). Ninety-four percent of patients underwent surgery and 86% had postoperative radiotherapy. Six patients were treated with targeted therapies. The 3-year overall survival (OS) was 74% and the 3-year disease-free survival (DFS) was 44%. Tumor stages III to IV reduced DFS (hazard ratio [HR] 4.3; P = .04). The N2/3 class reduced distant metastasis-free survival (HR 7.3; P = .007).

CONCLUSION

Salivary duct carcinoma prognosis is poor and is correlated with tumor stage and lymph node classification. Androgen receptor and HER2/neu should be tested as they offer the possibility of targeted therapies.

Frequent PTEN loss and differential HER2/PI3K signaling pathway alterations in salivary duct carcinoma: Implications for targeted therapy

BACKGROUND

Patients with advanced primary and recurrent salivary duct carcinoma (SDC), a rare and lethal malignancy, have limited therapeutic options. Novel small-molecule agents aimed at targeting critical signaling associated with SDC tumorigenesis may lead to new therapeutic options for patients with these tumors. The human epidermal growth factor receptor 2 (HER2)/phosphoinositide 3-kinase (PI3K) axis, an important oncogenic pathway, has been targeted for therapy in several solid tumors. Currently, little is known about the role and clinical implications of alterations of the HER2/PI3K pathway in patients with SDC.

METHODS

The authors investigated the clinicopathologic features, genetic alterations, and expression of key members of the HER2/PI3K pathway in 43 primary tumors and conducted in vitro functional and targeted drug-response analyses on cell lines derived from salivary epithelial carcinomas.

RESULTS

In primary tumors, loss of phosphatase and tensin homolog (PTEN) expression was identified in 22 of 43 tumors (51%), overexpression of HER2 was observed in 12 of 43 tumors (28%), and phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutations were identified in 12 of 43 tumors (28%). Phosphorylated protein kinase B (p-AKT) was highly expressed in most tumors. Most tumors (70%) displayed mutually exclusive alterations of PI3K members, whereas 8 tumors (19%) had 2 or more concurrent abnormalities. In vitro studies demonstrated a direct association between PTEN loss and PI3K pathway activation and evidence of response to combined PI3Kα and PI3Kβ and/or pan-PI3K inhibitors.

CONCLUSIONS

The current analyses reveal frequent PTEN loss and mutually exclusive alterations of key PI3K pathway members in SDC and demonstrate in vitro evidence of a response to pan-PI3K inhibitors. These results provide a framework for a biomarker-based substratification of patients with SDC in future targeted therapy. Cancer 2018;124:3523-32. © 2018 American Cancer Society.

The implications of TrkA and MET aberrations in de novo salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive carcinoma with poor prognosis. Although anti-HER2 therapy is a potential treatment option for HER2-positive SDC, other potential therapeutic targets are not known, in particular for HER2-negative cases. In this study, the recently identified receptors tyrosine kinases MET and tropomyosin-receptor kinase (Trk) were investigated as potential therapeutic targets. A total of 28 consecutive, surgically resected, de novo SDC cases were selected after evaluating histology and immunohistochemical expression of androgen receptor. Immunohistochemical expression of c-erb2, TrkA, TrkB, TrkC, and c-MET was analyzed, and the genetic status of the HER2 and MET genes was investigated through dual-color silver in situ hybridization. High expression of c-MET or Trk was defined as that above the median value. Among the 28 SDC cases, 64.3% (18/28) were HER2-positive. c-MET expression varied, with a median H-score of 65 (range, 0 to 200). Copy number gain and amplification of MET were noted in 57.1% (16/28) and 10.7% (3/28) of cases, respectively. TrkA was variably expressed, with a median H-score of 100 (range, 0 to250). High TrkA expression was significantly related to an inferior overall survival rate in HER2-negative SDC. High expression of TrkA and c-MET and MET copy number gain/amplification were frequent events in SDC, and high expression of TrkA revealed the tendency to be related to poor prognosis in HER2-negative SDC. TrkA and MET may be possible therapeutic targets in SDC, especially in HER2-negative SDC.

Salivary Duct Carcinoma Metastasizing to the Small Bowel

We report a case of salivary duct carcinoma in a 47-year-old woman. The patient presented with symptoms simulating acute appendicitis. Surgery revealed metastatic tumor in the wall of the small bowel. Two months later, a tumor of the right parotid gland was resected, and histologic analysis revealed a salivary duct carcinoma. To our knowledge, this is the first case of salivary duct carcinoma metastasizing to the small bowel with manifestations of metastatic disease as the prominent symptom.

Impact of hematological inflammatory markers on clinical outcome in patients with salivary duct carcinoma: a multi-institutional study in Japan

The prognostic role of modified Glasgow Prognostic Score (mGPS), neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) in patients with salivary duct carcinoma (SDC) remains unclear. We conducted a multi-institutional retrospective cohort study of 140 SDC patients. The survival impact of these hematological markers was evaluated using multivariate proportional hazard models.High mGPS (≥1) was significantly associated with worse survival (3-year overall survival (OS): 16.7% vs 66.1%, p-value=0.003; 3-year progression-free survival (PFS): 0.0% vs 27.9%, p-value<0.001). Additionally, high C-reactive protein (CRP) (≥0.39 mg/dl) was significantly associated with worse survival (3-year OS: 32.1% vs 68.2%, p-value=0.001; 3-year PFS: 7.1% vs 31.1%, p-value<0.001). These associations were consistent with multivariate analysis adjusted for established prognostic factors. Although we also found significant association of high NLR (≥2.5) with OS (HR 1.80; 95% confidence interval, 1.05-3.08) in multivariate analysis, this association were inconsistent with the results of PFS. In addition, we found no significant associations of PLR with survival. In conclusion, we found that mGPS, CRP and NLR were identified as prognostic factors associated with survival in SDC patients.

Primary ductal adenocarcinoma of lacrimal gland: Two case reports and review of the literature

A 64-year-old male presented with progressive proptosis of the left eye for 3 months. Orbital computed tomography (CT) demonstrated a 3.9 cm infiltrative mass over the superotemporal quadrant of the left orbit. Pathology of biopsy revealed a ductal adenocarcinoma of lacrimal gland with positive immunohistochemical staining for androgen receptor (AR), cytokeratin-7 (CK7), and gross cystic disease fluid protein 15 (GCDFP-15). The patient received orbital exenteration and adjuvant chemoradiotherapy. No recurrence or metastasis was noted 27 months after treatment. Another case was a 64-year-old male who came for proptosis of the right eye and diplopia for 3 weeks. Orbital CT revealed a 5 cm infiltrated right superotemporal orbital mass with destruction of the lateral and inferior orbital walls. Biopsy showed primary ductal adenocarcinoma of lacrimal gland with positive immunohistochemical staining for CK7, AR, and epidermal growth factor receptor. The patient underwent exenteration and concomitant chemoradiotherapy. However, lung and neck metastasis was noted 21 months after surgery. Collectively, 26 cases in the literature were reviewed. The mean age was 57 years old and male was prevalent (73%). Most immunohistological staining showed positive for AR (46%), CK7 (46%), Ki-67 (38%), and GCDFP-15 (35%). More than half of the patients developed metastasis and one-third of the patients died of disease. Early diagnosis, treatment, and long-term follow-up are required for this aggressive tumor.

Primary salivary duct carcinoma arising from the Stensen duct

This report describes a salivary duct carcinoma (SDC) arising from the extraglandular portion of the Stensen duct. The patient was a 56-year-old man who presented with a palpable, elastic, hard mass without tenderness in the right cheek. Computed tomography revealed a tumor of the extraglandular portion of the Stensen duct. Supraomohyoid right neck dissection and total right parotidectomy were performed, and the histologic diagnosis was SDC of the Stensen duct. Postoperatively, the patient received no additional treatment. Neither recurrence nor metastasis was observed during 4 years of follow-up examination. SDC of the Stensen duct is extremely rare. To our knowledge, there is no report that describes primary SDC arising from that location. We also believe this is the first report that describes the clinical course of primary SDC arising from a Stensen duct.

Salivary duct carcinoma treated with cetuximab-based targeted therapy: A case report

Salivary duct carcinoma is a highly aggressive disease with a poor prognosis. Surgical resection is currently the only curative treatment, as there is no effective systemic therapy for this malignancy. Recently, trastuzumab has been shown to exhibit therapeutic efficacy in the treatment of salivary duct carcinoma; similarly, molecularly targeted agents, such as cetuximab, are expected to be useful for salivary duct carcinoma treatment. We herein describe the case of a 56-year-old man diagnosed with salivary duct carcinoma in the left submandibular region, with ipsilateral multiple metastases to the neck lymph nodes. Radical resection of the tumor and submandibular gland with neck dissection were performed. One month after radical surgery, computed tomography (CT) scans indicated metastasis in the lower lobe of the left lung. CT-guided transthoracic fine-needle aspiration biopsy revealed a single metastasis and lung metastasectomy was immediately performed. The tumor cells of the primary lesion and those of the lung metastasis were immunohistochemically positive for epidermal growth factor receptor. One month later, multiple right lung metastases appeared, and the patient was treated with cisplatin/5-fluorouracil (5-FU) chemotherapy plus cetuximab, achieving a complete radiographic response. However, multiple lung metastases developed during adjuvant weekly cetuximab monotherapy. Subsequently, treatment with S-1 and weekly cetuximab was initiated, and the multiple lung metastases have been maintained as stable disease for 5 months. To the best of our knowledge, this is the first report of cetuximab use for the treatment of salivary duct carcinoma. Although cisplatin/5-FU chemotherapy plus cetuximab was efficacious in treating the lung metastasis, cetuximab monotherapy was insufficient for controlling tumor growth.

Significant and durable clinical benefit from trastuzumab in 2 patients with HER2-amplified salivary gland cancer and a review of the literature

BACKGROUND

Salivary ductal carcinoma and carcinoma ex pleomorphic adenoma (CEPA) are aggressive salivary gland cancers with poor prognosis. The standard of care is resection with or without radiotherapy, and there are no established systemic therapy options.

METHODS

We describe 1 patient with metastatic CEPA and 1 patient with metastatic recurrent salivary duct carcinoma whose tumors were evaluated by comprehensive genomic profiling. Testing identified human epidermal growth factor receptor 2 (HER2) amplification in both patients, and an additional activating HER2 mutation in the CEPA case.

RESULTS

Both patients were treated with the HER2-targeting monoclonal antibody trastuzumab (herceptin) plus chemotherapy and experienced rapid responses. Subsequently, both patients were given single-agent maintenance trastuzumab and continue to experience durable disease control.

CONCLUSION

Given the poor prognosis for salivary gland cancers and the limited treatment options upon recurrence or metastasis, patients should be tested for all classes of HER2 alterations. In cases with HER2 overexpression or activation, targeted therapies, such as trastuzumab are promising. © 2016 Wiley Periodicals, Inc. Head Neck 39: E40-E44, 2017.

Programmed death ligand-1 expression is associated with poor disease free survival in salivary gland carcinomas

BACKGROUND AND OBJECTIVES

The immune checkpoint ligand programmed death ligand-1 (PD-L1) is expressed in various carcinomas and allows carcinoma cells to elude the immune system. PD-L1 expression is associated with the response to anti-programmed death 1 (PD-1)/PD-L1 drugs. This study aimed to clarify the relationship between PD-L1 expression and clinicopathological factors of salivary gland carcinomas (SGCs) and identify its clinical significance.

METHODS

PD-L1 expression was examined by immunohistochemical analysis using a tissue microarray comprised of 219 surgically resected SGC specimens. Detailed clinicopathological factors, including patient outcome, were available for all cases.

RESULTS

A case showing complete membranous expression of PD-L1 in more than 1% of whole carcinoma cells was considered positive by ROC analysis. A total of 50 (22.8%) patients showed PD-L1 expression in SGC cells. Positive PD-L1 expression was significantly associated with poor disease free survival (P < 0.001) and overall survival (P < 0.001). Multivariate analysis revealed that positive PD-L1 expression was one of the independent predictors for poor disease free survival (hazard ratio = 2.287, 95% confidence interval = 1.24-4.15; P = 0.008).

CONCLUSIONS

Positive PD-L1 expression was significantly associated with poor disease free survival of SGCs, suggesting that antibody therapies targeting PD-1/PD-L1 may have potential application in SGCs. J. Surg. Oncol. 2016;114:36-43. © 2016 Wiley Periodicals, Inc.

Pathological response of salivary duct carcinoma to trastuzumab and docetaxel therapy

Salivary duct carcinoma (SDC) has a poor prognosis owing to the high incidence of distant metastasis. Approximately 40 % of SDCs are positive for human epidermal growth factor receptor 2 (HER2), suggesting that anti-HER2 therapy for cases with distant metastasis may be effective. However, the pathological response of SDC metastases to anti-HER2 therapy has not been reported. A 44-year-old man was diagnosed with HER2-positive SDC of the submandibular gland with multiple distant metastases. After six cycles of trastuzumab/docetaxel therapy, the patient achieved clinical partial response for the primary tumor and complete response for the neck and distant metastases. Subsequently, the patient underwent submandibular gland resection and neck dissection. On histopathological examination, very few viable cancer cells were identified in the resected primary tumor. Unfortunately, the patient died of multiple distant metastases 12 months after initial treatment. Trastuzumab/docetaxel therapy can elicit a clinical and pathological response in HER2-positive SDC.

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.

Salivary duct carcinoma: Treatment, outcomes, and patterns of failure

BACKGROUND

Salivary duct carcinoma is rare, with distinct morphology and behavior. We reviewed our institutional experience with salivary duct carcinoma, aiming to characterize clinical behavior and treatment outcomes.

METHODS

All salivary duct carcinomas treated curatively between 1999 and 2010 were reviewed. Overall survival (OS), locoregional control, distant control, and patterns of failure were analyzed. Multivariate analysis identified predictors of OS.

RESULTS

Fifty-four patients with salivary duct carcinoma (parotid gland = 49; submandibular gland = 5) were included in the analysis. Fifty-three patients underwent primary surgery, and 48 (89%) received postoperative radiotherapy (RT; median dose = 60 Gy). Median follow-up was 5.7 years. The 5-year OS, locoregional control, and distant control were 43%, 70%, and 48%, respectively. Nine local (6 involving facial nerve), 10 regional, and 28 distant failures were identified. Multiple pathologic involved lymph nodes (pN2b/N2c) predicted reduced OS (hazard ratio [HR] = 3.6; p = .02).

CONCLUSION

Distant recurrence is common. Presence of pN2b/N2c disease is associated with reduced OS. Local recurrence frequently involves the facial nerves. © 2015 Wiley Periodicals, Inc. Head Neck 38: E820-E826, 2016.

Salivary duct carcinoma: A clinopathological report of 11 cases

The aim of the present study was to summarize the clinicopathological and immunohistochemical characteristics of salivary duct carcinoma (SDC) and to evaluate the currently available treatment modalities. Between 2001 and 2011, 11 patients with SDC were diagnosed and treated at the Affiliated Hospital of Stomatology of Nanjing University (Nanjing, Jiangsu, China). The present study retrospectively reviewed the clinicopathological and immunohistochemical data of these 11 patients and the results indicated that the parotid gland was the most commonly affected site, followed by the submandibular gland and the palate. Furthermore, the mean age of onset was 58.8 years and all cases were treated with surgery, with 72.7% receiving post-operative radiation therapy. The range for the follow-up period was 10-89 months and of the 11 patients investigated, only two succumbed to the disease. In addition, the two-year overall survival rate was 75% according to Kaplan-Meier analysis and the mean overall survival time was 72.8 months. In conclusion, the present study determined that the site of the malignancy is the best predictor of survival in patients with the rare salivary malignancy SDC, while age, gender, T stage, N stage, American Joint Committee on Cancer stage, nerve paralysis, post-operative radiation, neck dissection, and protein expression levels of Ki-67, androgen receptor and human epidermal growth factor-2/neu are less influential factors.

Prognostic factors in adenocarcinoma of the salivary glands

OBJECTIVES

We aimed to characterize prognostic factors and outcomes in adenocarcinomas of the salivary glands.

MATERIALS AND METHODS

Patients were identified and retrospectively reviewed for clinical and pathologic tumor characteristics. Low and high grade adenocarcinoma histologies were separated and analyzed. Treatment regimens and patient-related outcomes were recorded and measured.

RESULTS

A total of 51 adenocarcinomas of the salivary glands were reviewed. The most common locations of disease were the superficial lobe of the parotid gland, followed by the deep lobe. Five-year overall and disease free survival rates were 43% and 37%. Univariate analysis identified the following as negative prognostic factors: symptoms of a fixed mass or rapid growth, advanced tumor or nodal stage, and perineural or lymphovascular invasion. Facial nerve paralysis was not found to be a significant prognostic variable. Multivariate analysis confirmed the independent negative prognostic importance of the following characteristics: presentation with a fixed mass or rapid growth, diagnosis of adenocarcinoma not otherwise specified, and positive surgical margins.

CONCLUSIONS

Our results identify several important prognostic factors associated with overall survival in adenocarcinoma of the salivary glands. These prognostic variables encompass symptoms on presentation, clinical and pathologic tumor stage characteristics, and treatment-related factors; all of which are important in patient counseling and may provide impetus for determining treatment escalation.

Is there a role of adjuvant treatment for salivary duct carcinoma?

Objective:

To determine the clinical effect of post-operative radiotheraphy and systemic chemotherapy for the treatment of salivary duct carcinoma.

Study design:

Retrospective review.

Design:

The medical records of 26 patients treated by surgery with or without radiotheraphy and/or systemic chemotherapy for salivary duct carcinoma were retrospectively reviewed to investigate the role of post-operative adjuvant treatment for the patients' prognosis.

Results:

The overall three-year and five-year survival rates were 54 and 48.1 per cent, respectively. There was no correlation with the clinical stage and the patients' prognosis. The overall three-year survival of the patients with or without post-operative radiotheraphy was 64 and 33 per cent, respectively (p = 0.29). The overall three-year survival of the patients with or without post-operative chemotherapy was 53 and 56 per cent, respectively (p = 0.78).

Conclusion:

Post-operative adjuvant therapy did not improve the patients' overall prognosis with salivary duct carcinoma. Developing novel treatment modalities may be necessary to improve the prognosis of this aggressive disease.

Clinicopathologic study of salivary duct carcinoma and the efficacy of androgen deprivation therapy

OBJECTIVE

Salivary duct carcinoma is a rare and aggressive tumor of the salivary glands. The objectives of this study were to investigate the clinicopathological features of salivary duct carcinoma and to determine whether androgen deprivation therapy should be recommended.

STUDY DESIGN AND METHODS

The clinical records of seven patients diagnosed with salivary duct carcinoma between 2002 and 2012 were retrospectively assessed. Tumor specimens were examined for overexpression of human epidermal growth factor receptor 2 (HER2) and androgen receptor by immunohistochemistry. A case of androgen receptor-positive salivary duct carcinoma who received androgen deprivation therapy is presented.

RESULTS

Of the seven patients, 43% had recurrences and metastases, and the 5-year survival rate was 68.6%. All patients were androgen receptor-positive, and 71% were HER2-positive. One patient, a 66-year-old man with androgen receptor-positive salivary duct carcinoma, received oral bicalutimide for 14 months and practically all lung metastases disappeared.

CONCLUSION

Androgen receptor is often overexpressed in salivary duct carcinoma. Androgen deprivation therapy is safe and should be considered for patients with androgen receptor-positive salivary duct carcinoma.

Alterations associated with androgen receptor gene activation in salivary duct carcinoma of both sexes: potential therapeutic ramifications

PURPOSE

To investigate the molecular events associated with the activation of androgen receptor (AR) as a potential therapeutic target in patients with salivary duct carcinoma (SDC).

EXPERIMENTAL DESIGN

Comprehensive molecular and expression analysis of the AR gene in 35 tumor specimens (20 males and 15 females) and cell lines derived from SDC using Western blotting and RT-PCR, FISH analysis, and DNA sequencing was conducted. In vitro and in vivo animal studies were also performed.

RESULTS

AR expression was detected in 70% of the tumors and was mainly nuclear and homogenous in both male and female SDCs, although variable cytoplasmic and/or nuclear localization was also found. We report the identification of ligand-independent AR splice variants, mutations, and extra AR gene copy in primary untreated SDC tumors. In contrast to prostate cancer, no AR gene amplification was observed. In vitro knockdown of AR in a female derived SDC cell line revealed marked growth inhibition in culture and in vivo androgen-independent tumor growth.

CONCLUSIONS

Our study provides new detailed information on the molecular and structural alterations associated with AR gene activation in SDC and sheds more light on the putative functional role of AR in SDC cells. On the basis of these data, we propose that patients with SDC (male and female) can be stratified for hormone-based therapy in future clinical trials.

Postoperative radiotherapy in salivary ductal carcinoma: a single institution experience

Purpose

We reviewed treatment outcomes and prognostic factors for patients with salivary ductal carcinoma (SDC) treated with surgery and postoperative radiotherapy from 2005 to 2012.

Materials and Methods

A total of 16 patients were identified and 15 eligible patients were included in analysis. Median age was 61 years (range, 40 to 71 years) and 12 patients (80%) were men. Twelve patients (80%) had a tumor in the parotid gland, 9 (60%) had T3 or T4 disease, and 9 (60%) had positive nodal disease. All patients underwent surgery and postoperative radiotherapy. Postoperative radiotherapy was delivered using 3-dimensional conformal radiotherapy or intensity-modulated radiotherapy. Locoregional failure-free survival (LRFFS), distant failure-free survival (DFFS), progression-free survival (PFS), and overall survival (OS) were calculated using the Kaplan-Meier method. Differences in survival based on risk factors were tested using a log-rank test.

Results

Median total radiotherapy dose was 60 Gy (range, 52.5 to 63.6 Gy). Four patients received concurrent weekly chemotherapy with cisplatin. Among 10 patients who underwent surgery with neck dissection, 7 received modified radical neck dissection. With a median follow-up time of 38 months (range, 24 to 105 months), 4-year rates were 86% for LRFFS, 51% for DFFS, 46% for PFS, and 93% for OS. Local failure was observed in 2 patients (13%), and distant failure was observed in 7 (47%). The lung was the most common involved site of distant metastasis.

Conclusion

Surgery and postoperative radiotherapy in SDC patients resulted in good local control, but high distant metastasis remained a major challenge.

Case report: anti-hormonal therapy in the treatment of ductal carcinoma of the parotid gland

Background

Ductal carcinomas of the parotid gland are rare, highly aggressive, have a poor prognosis and are histologically similar to Ductal Breast Cancer. We report what we believe to be the first case in literature of metastatic salivary duct carcinoma (SDC) of the parotid gland with objective response to tamoxifen and aromatase inhibitors, achieving a long-term stability of disease with no associated toxicity.

Case presentation

A 70-year-old female was referred to our institution for treatment of a painless nodular lesion in the scalp, localized in the frontal region of the cranium. A biopsy was taken and tested positive for metastatic ductal carcinoma. On PET CT hypermetabolic nodules were localized in the left parotid gland (11 mm), right parotid gland (10 and 12 mm), submandibular node (11 mm) and left cervical node (10 mm). A salivary ductal carcinoma was considered to be the primary tumor. The patient was subsequently started on tamoxifen, with a complete response from the scalp nodule and left parotid nodule, while the right parotid nodule demonstrated a partial response that maintained stable for 2 years until progression. Anastrazol was chosen as the next line of treatment, achieving 6 more months of stable disease. As a pseudo-adjuvant treatment, surgical resection of the right parotid lesion was performed and helped achieve two years of disease stability.

Conclusions

Estrogen receptor antagonists such as tamoxifen or aromatase inhibitors may represent a target for the establishment of a safe alternative and novel therapy for SDC, however more accurate data obtained from larger studies are required.

Intratumoral heterogeneity of HER2 protein and amplification of HER2 gene in salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive adenocarcinoma of the salivary glands, and accounts for 1-3% of all malignant salivary gland tumors, resembling morphologically invasive ductal carcinoma (IDC) of the breast. In contrast to IDC of the breast and gastric carcinoma (GC), the study of human epidermal growth factor receptor 2 (HER2) in SDC has not progressed. Therefore, we investigated the relationship between HER2 protein expression and amplification of the HER2 gene, and compared them in terms of intratumoral heterogeneity (ITH) in 13 cases of SDC using immunohistochemistry and dual color in situ hybridization. We found seven cases with protein overexpression (53.8%) and five cases with gene amplification (38.5%) in accordance with ASCO/CAP guidelines. ITH of HER2 protein expression was seen in seven cases (53.8%). Interestingly, the ratio of the HER2 gene showed homogenous distribution with or without the presence of ITH of HER2 protein expression. SDC tends to have more ITH of HER2 protein similarly to GC, in contrast to IDC of the breast. ITH of HER2 protein in SDC has no heterogeneity of the HER2 gene amplification. The mechanism of HER2 protein expression in SDC might proceed through a more complex pathway relative to that of IDC of the breast.

Minor salivary gland tumors in the Indian population: A series of cases over a ten year period

PROBLEM CONSIDERED

Minor salivary glands are found in the sino-nasal cavities, oropharynx, larynx and trachea with the majority being found in the oral cavity. 80% or more of minor salivary gland tumors are malignant and they tend to have a great variation in presentation and histology. We sought out to compare the presentation of various minor salivary gland tumors (MSGT's) in the Indian population as compared to that reported in different races and regions.

METHODS

We report a clinical case series in which 17 patients with biopsy proven minor salivary gland tumors both benign and malignant at various intraoral sites viz the palate, cheek, retromolar trigone and floor of the mouth were operated upon and followed up over a span of 10 years from 2001 to 2011.

RESULTS

15 patients were treated timely with complete removal of the lesions by wide local excision and as confirmed by histopathology; one patient with adenoid cystic carcinoma delayed in seeking treatment and expired within a month and another with salivary duct carcinoma presented with advanced disease and regional metastases in the form of multiple ipsilateral enlarged lymph nodes and distant metastases in the liver. He was given palliative radiotherapy but he died after six weeks of receiving treatment.

CONCLUSION

the results that we obtained for Indians were comparable to the various population studies done around the world.

Survival rates and prognostic factors for infiltrating salivary duct carcinoma: Analysis of 228 cases from the Surveillance, Epidemiology, and End Results database

BACKGROUND

The survival rates and prognostic factors for salivary duct carcinoma (SDC) are not clear.

METHODS

Survival estimates and prognostic factors were evaluated for 228 patients with SDC identified from the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

Median overall survival (OS) duration for patients with SDC was 79 months and 5-year disease-specific survival (DSS) rate was 64%. Among patients with SDC with lymph node involvement, larger primary tumor size (>3 cm) was associated with twice the risk of death (p < .03). Factors predictive of improved DSS were age (p = .01), tumor size (p = .006), tumor grade (p = .02), and lymph node involvement (p < .001). Adjuvant radiotherapy did not improve survival when compared to surgery alone for early-stage (I-II) disease (p = .28).

CONCLUSION

Younger patients with SDC (<50 years) showed a better prognosis. Primary tumor size and lymph node involvement were independent and additive risk factors for poor prognosis. The role of adjuvant radiotherapy in the treatment of SDC needs to be explored further.

Oncogenic PIK3CA mutation and dysregulation in human salivary duct carcinoma

Salivary duct carcinoma (SDC) is an aggressive malignant tumor with a high mortality, which resembles high-grade breast ductal carcinoma in morphology. The parotid gland is the most common location. Its molecular genetic characteristics remain largely unknown. We have previously reported high incidence of PIK3CA somatic mutations in head and neck squamous cell carcinoma, particularly in pharyngeal cancers. Here we examined the PIK3CA gene expression status and hotspot mutations in six cases of SDC by immunohistochemistry and genomic DNA sequencing. Immunohistochemistry showed that PIK3CA expression was elevated in all six patients with SDC. By DNA sequencing, two hotspot mutations of the PIK3CA gene, E545K (exon 9) and H1047R (exon 20), were identified in two of the six cases. Our results support that oncogenic PIK3CA is upregulated and frequently mutated in human SDC, adding evidence that PIK3CA oncogenic pathway is critical in the tumorigenesis of SDC, and may be a plausible drug target for this rare disease.

Salivary duct carcinoma with rhabdoid features: report of 2 cases with immunohistochemical and ultrastructural analyses

BACKGROUND

Salivary duct carcinoma with rhabdoid features is extremely rare.

METHODS

We report 2 cases of salivary duct carcinoma with rhabdoid features treated at our institution.

RESULTS

Case 1 was a 44-year-old Japanese man who had swelling in the left parotid region. This tumor consisted of residual pleomorphic adenoma and widely invasive carcinoma, which showed a diffuse growth pattern by atypical rhabdoid cells. Case 2 was a 66-year-old Japanese man who had swelling of the right cervical region. This submandibular tumor was also composed of both residual pleomorphic adenoma region and invasive adenocarcinoma components, whereas some metastatic lesions were purely composed of rhabdoid cells. Such cells were strongly and diffusely positive for cytokeratins (CKs), gross cystic disease fluid protein-15 (GCDFP), and androgen receptor (AR). Case 1 was also positive for Her-2 and p53.

CONCLUSION

Both patients were diagnosed with carcinoma ex pleomorphic adenoma and their carcinomatous components were composed of salivary duct carcinoma with rhabdoid features, which is a highly aggressive tumor, similar to salivary duct carcinoma.

Salivary duct carcinoma of the parotid gland: is adjuvant HER-2-targeted therapy required?

PURPOSE

Salivary duct carcinoma (SDC) of the parotid gland is a highly aggressive and uncommon tumor. Overexpression of human epidermal growth factor receptor 2 (HER-2) is characteristic of SDC. HER-2 overexpression is considered a poor prognostic marker for SDC, and anti-HER-2 therapy has been suggested as a therapeutic option.

MATERIALS AND METHODS

Two patients with SDC were analyzed for HER-2 overexpression and gene amplification using immunohistochemistry and fluorescence in situ hybridization.

RESULTS

In 1 patient, no expression of HER-2 was found. In the other patient, HER-2 was demonstrated. The patient with HER-2 overexpression had a worse prognosis, and trastuzumab proved to be an effective treatment.

CONCLUSIONS

The present results have also suggested that HER-2 overexpression is associated with a poor prognosis. Therefore, HER-2 status should be evaluated at least in the presence of advanced SDC, and targeted therapy should be considered in the adjuvant setting.

[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.

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.

Trastuzumab for the treatment of salivary duct carcinoma

OBJECTIVE

Salivary duct carcinoma (SDC) is a rare and aggressive malignancy with high mortality and poor response to treatment. A significant fraction of SDCs are HER2 positive. This retrospective review examines HER2 testing in SDC and the outcome of trastuzumab-based therapy in adjuvant and palliative settings.

METHODS

A total of 13 patients with SDC and HER2/neu expression by immunohistochemistry of 1-3+ were treated with trastuzumab in adjuvant (n = 8) or palliative (n = 5) setting. Adjuvant therapy consisted of concurrent radiation and chemotherapy with weekly paclitaxel, carboplatin, and trastuzumab (TCH) for 6 weeks followed by TCH for 12 weeks and trastuzumab alone for 1 year. Palliative treatment for metastatic disease consisted of TCH every 3 weeks for 6 cycles followed by trastuzumab for variable time periods with or without second-line chemotherapy for progression. All patients had fluorescence in situ hybridization testing for HER2/neu gene amplification.

RESULTS

The median duration of follow-up was 27 months (range: 8-48 months). In all, 62% of adjuvant patients (5/8) had no evidence of disease more than 2 years from completion of therapy. All patients with metastatic disease (5/5 patients) responded to treatment with TCH. One patient achieved a complete response and remains with no evidence of disease 52 months after initiation of TCH. The median duration of response was 18 months (range: 8-52 months).

CONCLUSION

HER2/neu positivity and treatment with trastuzumab correlated well with long-term survival and response in our patients. Based on this data, we propose that HER2/neu status be examined routinely in all patients with SDCs and the treatment be directed accordingly.

Detection of novel actionable genetic changes in salivary duct carcinoma helps direct patient treatment

PURPOSE

Salivary duct carcinomas (SDC) are a rare and aggressive subtype of salivary gland cancers for which cytotoxic chemotherapy has limited efficacy. We investigated whether genotyping analysis could detect novel tumor-specific mutations that would help direct SDC patient treatment using targeted agents.

EXPERIMENTAL DESIGN

We genotyped 27 SDC archival specimens from patients followed at Massachusetts General Hospital and Massachusetts Eye and Ear Infirmary (Boston, MA) between 2000 and 2011. These included the tumors of 8 patients who were tested prospectively. Targeted mutational analysis of 13 clinically relevant cancer genes was conducted using SNaPshot multiplexed genotyping. FISH was conducted to detect HER2 gene amplification. Patient medical records and tumor histopathologic features were retrospectively reviewed.

RESULTS

Mutually exclusive genetic aberrations were detected in 15 of 27 (56%) tumors, including 2 (7%) mutations in BRAF, 5 (19%) mutations in PIK3CA, and 8 (30%) cases of HER2 gene amplification. To our knowledge, this is the first time that BRAF and PIK3CA mutations have been reported in this tumor type. Prospective clinical testing of 8 patients with SDC identified actionable genetic alterations in 6 tumors and influenced therapeutic decisions for all 6 patients.

CONCLUSION

SNaPshot molecular profiling identified novel genetic changes in SDCs, expanded the therapeutic options for patients with this rare tumor, and is changing SDC management at our institution. These findings highlight the importance of using broad-based genetic profiling to expedite the identification of effective-targeted therapies for patients with rare malignancies.

Immunohistochemical analysis of thymic carcinoma focusing on the possibility of molecular targeted and hormonal therapies

OBJECTIVE

Thymic carcinoma is a rare mediastinal malignant tumor, and in many patients, the tumor is detected in an inoperable advanced stage. Even when chemotherapy is administered to such patients, the patients show a poor response. We investigated new biomarkers of therapeutic molecular targets.

METHODS

This study included 44 patients diagnosed and treated for primary thymic epithelial tumors at Showa University Northern Yokohama Hospital, Showa University Hospital, and Showa University Fujigaoka Hospital from 2003 to 2011. We investigated new biomarkers of therapeutic molecular targets, such as the peroxisome proliferator-activated receptor γ (PPARγ), insulin-like growth factor 1 receptor (IGF1R), epidermal growth factor receptor (EGFR), estrogen receptor (ER), progesterone receptor (PgR), androgen receptor (AR), human epidermal growth factor type 2 (HER2)/neu, CD44, and L-type amino acid transporter 1 (LAT1), in thymic tumors.

RESULT

Immunohistochemical analysis showed that the PPARγ positivity rate in thymic carcinoma was 32 %, which was significantly higher than that in thymoma (4 %). The IGF1R positivity rate in thymic carcinoma was 73 %, which was significantly higher than that in thymoma (27 %).

CONCLUSION

Therefore, by examining the expressions of PPARγ and IGF1R, it would be possible to identify therapy-responsive patients and to improve results of thymic carcinoma treatment.

Salivary gland carcinomas

INTRODUCTION

Salivary gland carcinomas are rare tumours of heterogeneous morphology that require distinctive surgical and adjuvant therapy.

METHODS

Relevant studies were electronically searched in PubMed and reviewed for innovative and important information.

RESULTS

Recent insights in genetic alterations like chromosomal aberrations, expression of receptor tyrosine kinases, malfunction of tumour suppressor genes or DNA promoter methylations increased the knowledge about aetiology and pathogenesis. New histological subtypes are recognised, and a three-tiered grading system seems reasonable. Ultrasound remains the basic diagnostic imaging procedure. New developments comprise the diffusion-weighed magnetic resonance imaging, while fluorodeoxyglucose positron emission tomography/computed tomography shows good diagnostic accuracy in detecting distant metastases and local recurrence. Fine-needle aspiration cytology helps in differentiating a neoplasia from a non-neoplastic lesion while being unreliable in recognising malignancy. In contrast, additional core needle biopsy and/or intraoperative frozen section diagnosis increase the accuracy in diagnosing a malignant lesion. Conservative parotid surgery with nerve monitoring remains state-of-the-art. Free flaps or musculoaponeurotic flaps are proposed for prevention of Frey's syndrome. As parotid cancer often shows skip metastases, complete ipsilateral neck dissection (level I-V) is indicated particularly in high-grade lesions. Adjuvant radio(chemo)therapy increases local tumour control, whereas overall survival is not necessarily improved. Current results of systemic chemotherapy or targeted therapy in advanced tumour stages are disappointing.

CONCLUSION

Despite several developments, salivary gland carcinomas remain a heterogeneous group of tumours challenging both pathologists and clinicians.

Treatment results of post-operative radiotherapy in patients with salivary duct carcinoma of the major salivary glands

OBJECTIVE

Salivary duct carcinoma (SDC) is a rare malignancy of high-grade pathological type. We evaluated clinical outcomes and prognostic factors in 35 patients with SDC treated post-operatively with adjuvant radiation.

METHODS

We retrospectively assessed overall survival, locoregional control and disease-free survival in 35 patients with SDC of the major salivary glands who underwent surgery and were subsequently treated with radiotherapy. The evaluated prognostic factors included gender, age, symptom duration, tumour site, tumour size, TNM classification, and the following pathological features: perineural invasion, lymphovascular invasion, extraparenchymal invasion and resection-margin status.

RESULTS

Of the 35 patients, 30 (85.7%) were male. Median age at initial diagnosis was 62 years (range 38-75 years). The parotid gland was the main site affected in 22 patients (62.9%). 18 patients (51.5%) had pathological T3/T4 tumours, and 26 (74.3%) showed pathological nodal involvement. Actuarial 5-year locoregional control, disease-free survival and overall survival rates were 63.3%, 47.4% and 55.1%, respectively. The cause-specific death rate was 31.4% (n=11). Pathological nodal involvement was correlated with distant metastasis (p=0.011). Lymphovascular invasion was significantly prognostic for distant metastasis-free survival (p=0.049), locoregional control (p=0.012) and overall survival (p=0.003) in a Cox proportional hazard model, whereas perineural invasion was only significantly prognostic for overall survival (p=0.005).

CONCLUSIONS

Surgery and post-operative radiotherapy were effective for locoregional control. Lymphovascular invasion and perineural invasion were significant prognostic factors in patients with SDC.

Salivary duct carcinoma: what is already known, and can we improve survival?

Salivary duct carcinoma is an aggressive malignancy with a high mortality rate, which phenotypically resembles high-grade breast ductal carcinoma. The parotid gland is the most common location. Standard treatment is surgery to the primary tumour together with post-operative radiotherapy. Despite this, there is a high rate of local recurrence, cervical nodal involvement and distant metastasis. Chemotherapy is currently considered only for end-stage, disseminated disease; however, current evidence indicates that chemotherapy used with radiotherapy may result in improved disease control and survival.Human epidermal growth factor receptor-2 is a proto-oncogene which is over-expressed in both breast ductal carcinoma and salivary duct carcinoma. Clinical studies of patients with metastatic breast cancer, using trastuzumab, a monoclonal antibody directed against human epidermal growth factor receptor-2, have shown significant efficacy in tumour response, resulting in improved survival. Such advances in immunohistochemistry, and in targeted immunotherapy for breast ductal carcinoma, should be applied to the treatment of salivary duct carcinoma.

Salivary duct carcinomas: clinical and CT and MR imaging features in 20 patients

INTRODUCTION

Salivary duct carcinoma (SDC) is an uncommon high grade adenocarcinoma of the salivary gland with a grave prognosis. The aim of this study was to investigate the clinical and CT and MR imaging features of SDC.

METHODS

We retrospectively evaluated the clinical and CT and MR imaging findings in 20 patients (14 men and six women; mean age, 59 years) with histologically proved SDC. We also tried to correlate clinicoradiological tumor staging with pathologic tumor staging in 17 patients who underwent surgery.

RESULTS

The tumor originated in the parotid gland (n = 11; 55%), the submandibular gland (n = 7; 35%) and the buccal space along the distal Stensen's duct (n = 2; 10%). Locoregional recurrence occurred in 41% and distant metastasis in 47%. Fifty-eight percent died of the disease with a mean survival period of 32 months after diagnosis. On CT and MR images, SDC was mostly seen as an ill-defined (85%) and infiltrative (60%) mass with frequent calcification (50%) and necrosis (80%). Although various signal intensities were seen on MR images, six of nine tumors contained the areas of marked hypointensity on T2-weighted images. Clinicoradiological tumor staging correlated well with pathologic tumor staging in 82% of the patients.

CONCLUSION

Ill-defined, infiltrative mass with calcification on CT scans and the areas of marked hypointensity on T2-weighted MR images may be useful radiologic features to suggest the diagnosis of SDC. CT and MR imaging are useful for staging of SDC.