Recurrent salivary gland cancer

Recurrence after primary salivary gland carcinoma: Frequency, survival, and risk factors

BACKGROUND

Primary salivary gland carcinomas (SGC) are rare neoplasms that present therapeutic challenges especially in recurrent tumors. The aim of this study was to investigate the incidence and distribution of tumor recurrence, associated risk factors, and survival.

METHODS

This analysis includes data from 318 patients treated for SGC between 1992 and 2020. Survival analysis was performed using the Kaplan-Meier method. Univariate and multivariate analyses were used to identify risk factors associated with recurrence.

RESULTS

21.7% of the patients developed recurrent disease after a mean of 38.2 months. In multivariate analysis, positive-resection margins, vascular invasion, and tumor localization in the submandibular gland and small salivary glands were independent factors for recurrence. The 5-year overall survival was 67%, the 5-year disease-free survival was 54%.

CONCLUSION

Tumor recurrence in SGC occurred in one out of five patients. In highly aggressive entities and patients with risk factors, treatment intensification should be considered.

Intraparotid node metastasis affects the long-term survival of patients with resectable recurrent parotid gland carcinoma

PURPOSE

The recurrence rate of parotid gland cancer is high, but research on the prognosis of recurrent parotid gland cancer (RPC) is relatively limited. We aim to determine the potential prognosis factors of RPC.

STUDY DESIGN

Retrospective cohort analysis.

SETTING

Tertiary cancer center.

METHODS

We conducted a retrospective review from 2012 to 2021 on RPC patients treated at the China National Cancer Center (CNCC). To analyze the impact of various variables on overall survival (OS) after recurrence, a univariate and multivariate Cox proportional hazard model was employed.

RESULTS

A total of 50/218 (23.0%) patients diagnosed with RPC and underwent surgery. The 5-year OS of all RPC patients in this cohort was 61.9%. 5 of 50 patients (10%) exhibited intraparotid node (IPN) metastasis. By univariate and multivariate analyses, we found that IPN metastasis was one of the prognostic factors of OS (p = 0.039) in RPC patients. The presence of IPN metastasis was also related to poor survival in individuals with negative cervical lymph nodes (CN0) (p = 0.011). In terms of the influence of surgical margins on prognosis, our findings revealed that RPC patients with negative margins exhibited a higher survival result than those with positive margins (p = 0.002).

CONCLUSION

According to this study, IPN metastasis indicate a high incidence of mortality in recurrent parotid cancer patients. Particularly, in CN0 patients, the presence of IPN metastasis was associated with poor survival in CN0 patients.

A comparison of two chemotherapy regimens in advanced, recurrent, or metastatic salivary gland carcinoma

Background

The efficacy of chemotherapy in locally advanced, recurrent, and metastatic salivary gland carcinomas (LA-R/M SGCs) is still undefined. We aimed to compare the efficacy of two chemotherapy regimens in LA-R/M SGC.

Materials and Methods

This prospective study compared paclitaxel (Taxol) plus carboplatin (TC) versus cyclophosphamide, doxorubicin, plus cisplatin (CAP) regimen in terms of overall response rate (ORR), clinical benefit rate (CBR), progression-free survival (PFS), and overall survival (OS).

Results

Between October 2011 and April 2019, 48 patients with LA-R/M SGCs were recruited. The ORRs of first-line TC and CAP regimens were 54.2% and 36.3%, respectively (P = 0.57). The ORRs in recurrent and de novo metastatic patients were 50.0% and 37.5% for TC and CAP, respectively (P = 0.26). The median PFS of TC and CAP arms were 10.2 and 11.9 months, respectively (P = 0.91). In the subanalysis, patients with adenoid cystic carcinoma (ACC) had longer PFS in the TC arm (14.5 vs. 8.2 months, P = 0.03), irrespective of the tumor grade (low grade: 16.3 vs. 8.9 months, high grade: 11.7 vs. 4.5 months; P = 0.03). The median OS rates were 45.5 and 19.5 months for TC and CAP groups, respectively (P = 0.71).

Conclusion

For patients with LA-R/M SGC, there was no significant difference between first-line TC and CAP in terms of ORR, PFS, and OS.

Management of Salivary Gland Malignancy: ASCO Guideline

PURPOSE

To provide evidence-based recommendations for practicing physicians and other healthcare providers on the management of salivary gland malignancy.

METHODS

ASCO convened an Expert Panel of medical oncology, surgical oncology, radiation oncology, neuroradiology, pathology, and patient advocacy experts to conduct a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 2000 through 2020. Outcomes of interest included survival, diagnostic accuracy, disease recurrence, and quality of life. Expert Panel members used available evidence and informal consensus to develop evidence-based guideline recommendations.

RESULTS

The literature search identified 293 relevant studies to inform the evidence base for this guideline. Six main clinical questions were addressed, which included subquestions on preoperative evaluations, surgical diagnostic and therapeutic procedures, appropriate radiotherapy techniques, the role of systemic therapy, and follow-up evaluations.

RECOMMENDATIONS

When possible, evidence-based recommendations were developed to address the diagnosis and appropriate preoperative evaluations for patients with a salivary gland malignancy, therapeutic procedures, and appropriate treatment options in various salivary gland histologies.Additional information is available at www.asco.org/head-neck-cancer-guidelines.

Fas-Fas Ligand Interplay in the Periphery of Salivary Gland Carcinomas as a New Checkpoint Predictor for Disease Severity and Immunotherapy Response

Salivary gland carcinomas (SGCs) are extremely morphologically heterogeneous, and treatment options for this disease are limited. Immunotherapy with immune checkpoint inhibitors (ICIs) represents a revolutionary treatment approach. However, SGCs remain largely resistant to this therapy. An increasing body of evidence suggests that resistance to ICI therapy is modulated by the Fas (CD95)–Fas ligand (FasL, CD178) interplay between tumor cells and immune cells. In this study, we examined the Fas–FasL interplay between tumor cells and tumor-infiltrating immune cells (TIICs) in the center and periphery of SGCs from 62 patients. We found that the Fas-expressing tumor cells accumulated in the center of SGC tumors with increasing tumor stage. Furthermore, this accumulation occurred regardless of the presence of TIICs expressing high levels of FasL. On the contrary, a loss of Fas-expressing TIICs with increasing tumor stage was found in the tumor periphery, whereas FasL expression in tumor cells in the tumor periphery correlated with tumor stage. These data suggest that SGC cells are resistant to FasL-induced apoptosis by TIICs but could utilize FasL to eliminate these cells in high-stage tumors to provide resistance to immunotherapy.

Postoperative Management of Salivary Gland Tumors

OPINION STATEMENT

Salivary gland tumors represent a heterogeneous group of neoplasms characterized by varied histologies and disease outcomes. Initial treatment for the primary and gross nodal disease is usually surgery. Management of the clinically node-negative neck depends upon the risk of lymph nodal involvement. This is usually determined by the AJCC "T" stage and histology. Both surgery and radiation may be utilized to address the lymph nodes at risk. This is especially important for minor salivary gland tumors. Radiation plays an important role in the adjuvant management of salivary gland tumors by reducing the risk of locoregional recurrence. Certain histologies like adenoid cystic carcinoma have a predilection for neurotropic spread to the skull base. Radiation is particularly important in controlling disease at the skull base. The role of concurrent chemotherapy in the adjuvant treatment of salivary gland tumors is not established and remains an area of active research. Certain histologies like salivary duct carcinoma exhibit readily identifiable molecular targets amenable to targeted therapy. Finally, advanced testing of these tumors using next-generation sequencing can also potentially identify molecular targets amenable to therapy. While useful in the management of metastatic disease, the role of these therapies in the adjuvant setting remains unknown.

Salivary Clear Cell Carcinoma Clinicopathologic Characteristics and Outcomes: A Population-Based Analysis

Background:

Salivary clear cell carcinoma is an uncommon, low-grade malignancy for which limited data describing predictive clinicopathologic factors and treatment outcomes exist because of rarity.

Methods:

The authors queried the Surveillance, Epidemiology, and End Results database from 1982 to 2014. Multivariate Cox and Kaplan-Meier analyses were performed to determine disease-specific survival (DSS) and predictive clinicopathologic factors.

Results:

One hundred ninety-eight patients with salivary clear cell carcinoma were included. Overall incidence was 0.011 per 100 000 individuals, with no significant annual percentage change across years (−0.93%, P = .632). Five-, 10-, and 20-year DSS rates were 81.3% (n = 117), 69.6% (n = 94), and 55.3% (n = 68), respectively. Men (hazard ratio, 4.74; P = .0087) and patients with regional (hazard ratio, 5.59; P = .018) or distant (hazard ratio, 8.9; P = .01) metastases carried a worse prognosis. Five-year DSS was greater in patients with localized disease (96.36%, P < .0001) than those with regional or distant metastases. Treatment with surgery alone had better 10-year DSS (86.3%) compared with treatment with combination radiation and surgery (57.6%) or radiation monotherapy (18.75%, P < .0001).

Conclusions:

Salivary clear cell carcinoma carries an overall good prognosis. Patients with localized disease and those treated with surgery alone have more favorable prognoses. Male patients and those with regional or distant metastatic disease at time of presentation carry a worse prognosis.

Level of Evidence:

N/A

Multifactorial Contribution of Notch Signaling in Head and Neck Squamous Cell Carcinoma

Head and neck squamous cell carcinoma (HNSCC) defines a group of solid tumors originating from the mucosa of the upper aerodigestive tract, pharynx, larynx, mouth, and nasal cavity. It has a metastatic evolution and poor prognosis and is the sixth most common cancer in the world, with 600,000 new cases reported every year. HNSCC heterogeneity and complexity is reflected in a multistep progression, involving crosstalk between several molecular pathways. The Notch pathway is associated with major events supporting cancerogenic evolution: cell proliferation, self-renewal, angiogenesis, and preservation of a pro-oncogenic microenvironment. Additionally, Notch is pivotal in tumor development and plays a dual role acting as both oncogene and tumor suppressor. In this review, we summarize the role of the Notch pathway in HNSCC, with a special focus on its compelling role in major events of tumor initiation and growth.

EGFR activation induced Snail-dependent EMT and myc-dependent PD-L1 in human salivary adenoid cystic carcinoma cells

Epithelial-to-mesenchymal transition (EMT) confers cancer cells the ability of invasion and metastasis. However, how does EMT contribute to evasion of immune surveillance is unclear, especially in salivary adenoid cystic carcinoma (SACC). In this study, we investigated the molecular link between EGF-induced EMT and the immune checkpoint ligand programmed death-ligand 1 (PD-L1) by immunoprecipitation (IP) and Westernblot analysis. Cell migration and invasion activity was assayed by transwell assay. Immunohistochemical (IHC) staining analysis was performed for measurement of EMT markers and PD-L1 expression levels in tumor tissues. We found that EGF-induced EGFR activation stabilized Snail expression and induced EMT in SACC. Interestingly, EGFR activation induced simultaneously both EMT and PD-L1 in SACC. Importantly, knockdown of Snail greatly suppressed EGF-induced EMT, but not EGF-induced PD-L1 expression; whereas knockdown of c-Myc strongly repressed PD-L1 expression, but not snail expression and EMT. The molecular link is strongly supported by robust correlations between the EMT markers and PD-L1 expression in human cancer samples.These results suggest that EGFR activated EMT and PD-L1 via two distinct mechanisms. EGFR activation induced EMT and PD-L1 expression in SACC. Snail is required for EGF-induced EMT, but not PD-L1 expression; whereas c-Myc is required for EGFR-mediated PD-L1 upregulation but not EMT. Thus, targeting activated EGFR may inhibit both EMT and PD-L1, which may potentiate the therapeutic effect of PD-L1-based immunotherapy, especially in the malignant subgroups of SACC patients with activated EGFR.

No evidence for human papillomavirus having a causal role in salivary gland tumors

BACKGROUND

Salivary gland malignancies are a very heterogeneous group of cancers, with histologically > 20 different subtypes, and prognosis varies greatly. Their etiology is unknown, however, a few small studies show presence of human papillomavirus (HPV) in some subtypes, although the evidence for HPV having a causal role is weak. The aim of this study was to investigate if HPV plays a causal role in the development of different parotid salivary gland tumor subtypes.

METHODS

DNA was extracted from 107 parotid salivary gland formalin fixed paraffin embedded tumors and 10 corresponding metastases, and tested for 27 different HPV types using a multiplex bead based assay. HPV DNA positive tumors were stained for p16INK4a overexpression by immunohistochemistry.

RESULTS

One of the 107 malignant parotid salivary gland tumors (0.93%) and its corresponding metastasis on the neck were positive for HPV16 DNA, and both also overexpressed p16INK4a. The HPV positive primary tumor was a squamous cell carcinoma; neither mucoepidermoid nor adenoid cystic tumors were found HPV positive.

CONCLUSIONS

In conclusion, HPV DNA analysis in a large number of malignant parotid salivary gland tumors, including 12 different subtypes, did not show any strong indications that tested HPV types have a causal role in the studied salivary gland tumor types.

Salivary gland stem cells: A review of development, regeneration and cancer

Salivary glands are responsible for maintaining the health of the oral cavity and are routinely damaged by therapeutic radiation for head and neck cancer as well as by autoimmune diseases such as Sjögren's syndrome. Regenerative approaches based on the reactivation of endogenous stem cells or the transplant of exogenous stem cells hold substantial promise in restoring the structure and function of these organs to improve patient quality of life. However, these approaches have been hampered by a lack of knowledge on the identity of salivary stem cell populations and their regulators. In this review we discuss our current knowledge on salivary stem cells and their regulators during organ development, homeostasis and regeneration. As increasing evidence in other systems suggests that progenitor cells may be a source of cancer, we also review whether these same salivary stem cells may also be cancer initiating cells.

Recurrent parotid gland carcinoma: how effective is salvage surgery?

OBJECTIVE

Recurrent parotid gland carcinomas (PGCs) are poorly characterized and studies focusing on this topic are rare due to their low incidence. The goal of this study is to analyze the therapeutic strategies, prognostic factors, and oncological outcomes of a series of patients with recurrent PGCs.

PATIENTS AND METHODS

Retrospective chart review (1997-2012) of patients with recurrent PGCs was initially treated with curative intent.

RESULTS

We identified 20 patients with recurrent PGCs. Eleven patients presented isolated local, regional, or distant metastases, while the rest had recurrences in multiple sites. Recurrent tumors tended to present more advanced T-stage (p = 0.01) and overall stage (p < 0.001), but not N-stage (p = 0.74) when compared to the initial tumors. Half the patients (50%) had distant metastases at the moment of recurrence diagnosis, and another three developed them after attempted salvage surgery. Only 8/20 patients with isolated local or regional recurrences were surgically salvaged with extended revision parotidectomy and neck dissection, respectively. The remaining 12 patients were managed on palliative basis. Overall survival (31.70 months vs. 20.73 months) and progression-free survival (28.70 months vs. 13.61 months) were not significantly different in patients managed surgically vs. palliatively.

CONCLUSION

Recurrent PGCs are aggressive neoplasms with a high rate of distant metastases. Surgical salvage can be considered in patients with limited local and/or regional recurrences. The alternative to surgical salvage is palliative management with different chemotherapeutic regimens. Survival does not differ between the two strategies in the present series.

Multidisciplinary Management of Salivary Gland Cancers

BACKGROUND

Salivary carcinomas are a rare group of biologically diverse neoplasms affecting the head and neck. The wide array of different histological entities and clinical presentations has historically limited attempts to establish well-defined treatment algorithms. In general, low-risk lesions can be managed with a single treatment modality, whereas advanced lesions require a more complex, multidisciplinary approach.

METHODS

The relevant literature was reviewed, focusing on diagnostic and treatment algorithms for salivary malignancies.

RESULTS

Salivary carcinomas with high-risk features require an aggressive treatment approach with complete surgical resection, neck dissection to appropriate cervical lymph-node basins, and postoperative radiotherapy.

CONCLUSIONS

The heterogeneity of salivary neoplasms represents a unique clinical challenge. Despite the multidisciplinary management paradigm detailed in this review, outcomes for advanced disease are unsatisfactory. Future progress will likely require the addition of novel systemic therapeutic strategies.

Diagnosis and Management of Malignant Salivary Gland Tumors of the Parotid Gland

Malignant parotid tumors are heterogeneous and diverse. Accurate diagnosis requires a pathologist familiar with the various histologic subtypes, immunohistochemistry stains, and common translocations. Clinical course varies according to tumor subtype, ranging from indolent, slow-growing adenoid cystic carcinoma to rapidly progressive, possibly fatal, salivary ductal carcinoma. Histologic grade is important in prognosis and therapy. Surgery remains the mainstay of treatment when negative margins can be achieved. Radiation improves locoregional control of tumors with high-risk features. Chemotherapy for parotid tumors can be disappointing. Studies of new targeted therapies have not offered significant benefits.

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.

Primary intraosseous adenoid cystic carcinoma of the mandible: a comprehensive review and analysis of four new cases with emphasis on morphologic, immunophenotypic, and molecular characteristics

OBJECTIVE

To comprehensively review the clinical manifestations, imaging, diagnosis, treatment, and pathologic features of primary intraosseous adenoid cystic carcinoma (PIACC) of the mandible and analyze PIACC histopathology and molecular features in four cases.

STUDY DESIGN

We reviewed the literature and retrospectively studied four cases of PIACC.

RESULTS

The clinical and imaging findings of PIACC are similar to other malignant or borderline-malignant mandible tumors. The four cases of PIACC included three males and one female (aged between 41 and 58 years). The histopathologic features of the tumors resembled those of ACC. We observed abundant osteoclasts resorbing bone at the leading edge of the tumors characterized by solid structure histology but not by the cribriform subtype. Additionally, all four cases showed abnormalities in the MYB gene and high expression of MYB protein. All patients survived for the duration of follow-up, and two patients had distant metastases (followed up for 3 to 36 months).

CONCLUSIONS

PIACC is extremely rare and is often clinically misdiagnosed. Different histologic subtypes could show different mechanisms of invasion of the mandible. MYB gene and protein expression abnormalities can be used as indicators for the precise diagnosis of PIACC.

Genetic alterations in salivary gland cancers

Salivary gland cancers are an incredibly heterogeneous group of tumors that include 24 histologically distinct tumor types. The use of new genetic methods has paved the way for promising advancements in our understanding of the molecular biology underlying each type of tumor. The objective of this review was to highlight common oncogenes, tumor suppressor genes, and cytogenetic and epigenetic changes associated with the most common tumor types: mucoepidermoid carcinoma, adenoid cystic carcinoma, salivary duct carcinoma, mammary analogue secretory carcinoma, hyalinizing clear cell carcinoma, carcinoma ex pleomorphic adenoma, and acinic cell carcinoma. Recent insights into the pathogenesis of each cancer subtype have helped better define and classify these tumors. Further research in salivary gland cancers should focus on determining the key genes involved in the tumorigenesis of each distinct malignancy and identifying individualized chemotherapies directed at these targets. Cancer 2016;122:1822-31. © 2016 American Cancer Society.

Anti-tumor effect of inhibition of IL-6 signaling in mucoepidermoid carcinoma

Mucoepidermoid carcinoma (MEC) is the most frequent malignant salivary gland cancer. Response to chemoradiotherapy is modest, and therefore radical surgery remains the standard-of-care. Emerging evidence suggests that Interleukin (IL)-6 signaling correlates with the survival of cancer stem cells and resistance to therapy. Here, we investigated whether inhibition of IL-6 receptor (IL-6R) signaling with tocilizumab (humanized anti-human IL-6R antibody) sensitizes MEC to chemotherapy using human mucoepidermoid carcinoma cell lines (UM-HMC) and correspondent xenograft models. In vitro, we observed that tocilizumab inhibited STAT3 phosphorylation but had no measurable effect in MEC cell viability (UM-HMC-1,-3A,-3B). In contrast, the anti-tumor effect of single agent tocilizumab on MEC xenografts was comparable to paclitaxel or cisplatin. Combination of tocilizumab with cisplatin or paclitaxel enhanced the inhibitory effect of chemotherapy on xenograft growth (P < 0.05), time to failure (P < 0.01), decreased vascular endothelial growth factor (VEGF) expression and tumor microvessel density (P < 0.05) without added systemic toxicities. Notably, tocilizumab decreased the fraction of MEC cancer stem cells (ALDH(high)CD44(high)) in vitro, and prevented paclitaxel-induced increase in the fraction of cancer stem cells in vivo (P < 0.05). Collectively, these findings demonstrate that tocilizumab enhances the anti-tumor effect of conventional chemotherapy in preclinical models of mucoepidermoid carcinoma, and suggest that patients might benefit from combination therapy with an inhibitor of IL-6R signaling and chemotherapeutic agent such as paclitaxel.

Aberrant Activation of the RANK Signaling Receptor Induces Murine Salivary Gland Tumors

Unlike cancers of related exocrine tissues such as the mammary and prostate gland, diagnosis and treatment of aggressive salivary gland malignancies have not markedly advanced in decades. Effective clinical management of malignant salivary gland cancers is undercut by our limited knowledge concerning the key molecular signals that underpin the etiopathogenesis of this rare and heterogeneous head and neck cancer. Without knowledge of the critical signals that drive salivary gland tumorigenesis, tumor vulnerabilities cannot be exploited that allow for targeted molecular therapies. This knowledge insufficiency is further exacerbated by a paucity of preclinical mouse models (as compared to other cancer fields) with which to both study salivary gland pathobiology and test novel intervention strategies. Using a mouse transgenic approach, we demonstrate that deregulation of the Receptor Activator of NFkB Ligand (RANKL)/RANK signaling axis results in rapid tumor development in all three major salivary glands. In line with its established role in other exocrine gland cancers (i.e., breast cancer), the RANKL/RANK signaling axis elicits an aggressive salivary gland tumor phenotype both at the histologic and molecular level. Despite the ability of this cytokine signaling axis to drive advanced stage disease within a short latency period, early blockade of RANKL/RANK signaling markedly attenuates the development of malignant salivary gland neoplasms. Together, our findings have uncovered a tumorigenic role for RANKL/RANK in the salivary gland and suggest that targeting this pathway may represent a novel therapeutic intervention approach in the prevention and/or treatment of this understudied head and neck cancer.

The Limitations of Routine Magnetic Resonance Imaging for Long-Term Post-Treatment Locoregional Surveillance of Salivary Carcinoma

BACKGROUND/AIMS

To determine the utility of head and neck magnetic resonance imaging (HN-MRI) for the routine surveillance of patients without concurrent symptoms or signs of recurrence more than 6 months after treatment for salivary gland carcinoma (SGC).

METHODS

This is a retrospective single-institution review of SGC patients from 2000 to 2011 who underwent one or more HN-MRI scans without concurrent suspicious symptoms or signs of recurrence more than 6 months after the completion of treatment, with at least 6 months of follow-up after each scan.

RESULTS

Out of an original 283 SGC patients treated surgically, 41 patients, who were disease free 6 months after treatment, had undergone 96 routine HN-MRIs without concurrent suspicious symptoms or signs. Ten out of the 41 patients (24%) experienced a false-positive finding with routine HN-MRI. None of the 96 HN-MRIs demonstrated a true-positive or false-negative finding.

CONCLUSION

More than 6 months after treatment, routine HN-MRI for the detection of locoregional recurrence of SGC has a low utility in patients without concurrent suspicious symptoms or signs. While these data support the judicious use of routine HN-MRIs, the managing physician should ultimately decide on the best course of surveillance for an individual patient based on the unique risk factors and circumstances present.

Oncocytoma of the parotid gland: a case report and review of the literature

We report the case of a patient who presented to the ENT service with left facial swelling of 5 months duration. Imaging studies revealed a dense expansive mass confined to the inside of the left deep parotid lobule and moderate enhancement following contrast media injection. Subsequently, a biopsy confirmed the presence of an oncocytoma. The patient was treated with total parotidectomy, complete tumor resection and sparing facial nerve surgery. Today, the patient is disease free and has no complications.

SOX10 is a novel marker of acinus and intercalated duct differentiation in salivary gland tumors: a clue to the histogenesis for tumor diagnosis

Salivary gland tumors are relatively rare and morphologically diverse and heterogeneous tumors; therefore, histogenesis-based tumor markers are sorely needed to aid in diagnosing and determining the cell type of origin. SRY-related HMG-box 10 (SOX10) protein is a transcription factor known to be crucial in the specification of the neural crest and maintenance of Schwann cells and melanocytes. In addition, positive expression has also been implicated in the major salivary gland. Here, we examined SOX10 expression in various salivary gland tumors to correlate this expression with myoepithelial markers. Overall, 76 malignant and 14 benign tumors were examined. SOX10 expression clearly delineated two distinct subtypes of human salivary gland tumors; acinic cell carcinomas, adenoid cystic carcinomas, epithelial-myoepithelial carcinomas, myoepithelial carcinomas, and pleomorphic adenomas, including the pleomorphic adenoma component of carcinoma, were SOX10 positive, while salivary duct carcinomas, mucoepidermoid carcinomas, an oncocytic carcinoma, Oncocytomas, and Warthin tumors were SOX10 negative. Also, SOX10 was expressed in solid-type or non-specific morphology salivary gland tumors, but was not expressed in poorly differentiated squamous cell carcinomas. In normal human salivary gland tissue, SOX10 expression was specific to the nuclei of acini and both luminal and abluminal cells of intercalated ducts but not in other sites. Moreover, the murine model suggested that SOX10 continued to be expressed from the developmental stage to adulthood in the acinar and both luminal and abluminal intercalated ducts in the major salivary gland. Thus, SOX10 is a novel marker for diagnosing and understanding the histogenesis of salivary gland tumors.

Follow-up strategies in head and neck cancer other than upper aerodigestive tract squamous cell carcinoma

Post-therapy follow-up for patients with head and neck cancer other than upper aerodigestive tract squamous cell carcinoma should meet several objectives: to detect both local, regional or distant recurrences, to evaluate acute and long-term treatment-related side effects, to guide the rehabilitation process, and to provide psychosocial support when needed. To our knowledge, there are no published reports in the literature dedicated to the follow-up of patients with these tumours. A comprehensive literature search for post-treatment follow-up strategies spanning from 1980 to 2012 was performed on several databases. This review focuses on malignant salivary gland tumors, soft tissue sarcomas, cutaneous squamous cell carcinomas, and sinonasal adenocarcinomas. Given the varying biological behavior and treatment-related factors and based on the literature, different recommendations are made on the follow-up of patients with the above-mentioned tumors.

Salivary gland cancer stem cells

Emerging evidence suggests the existence of a tumorigenic population of cancer cells that demonstrate stem cell-like properties such as self-renewal and multipotency. These cells, termed cancer stem cells (CSC), are able to both initiate and maintain tumor formation and progression. Studies have shown that CSC are resistant to traditional chemotherapy treatments preventing complete eradication of the tumor cell population. Following treatment, CSC are able to re-initiate tumor growth leading to patient relapse. Salivary gland cancers are relatively rare but constitute a highly significant public health issue due to the lack of effective treatments. In particular, patients with mucoepidermoid carcinoma or adenoid cystic carcinoma, the two most common salivary malignancies, have low long-term survival rates due to the lack of response to current therapies. Considering the role of CSC in resistance to therapy in other tumor types, it is possible that this unique sub-population of cells is involved in resistance of salivary gland tumors to treatment. Characterization of CSC can lead to better understanding of the pathobiology of salivary gland malignancies as well as to the development of more effective therapies. Here, we make a brief overview of the state-of-the-science in salivary gland cancer, and discuss possible implications of the cancer stem cell hypothesis to the treatment of salivary gland malignancies.

Cytomegalovirus-induced salivary gland pathology: resistance to kinase inhibitors of the upregulated host cell EGFR/ERK pathway is associated with CMV-dependent stromal overexpression of IL-6 and fibronectin

Background

Recently we identified a relationship between human cytomegalovirus (hCMV) and human salivary gland (SG) mucoepidermoid carcinoma (MEC) in over 90% of cases; tumorigenesis in these cases uniformly correlated with active hCMV protein expression and an upregulation of the EGFR → ERK pathway. Our previously characterized, novel mouse organ culture model of mouse CMV (mCMV)-induced tumorigenesis displays a number of histologic and molecular characteristics similar to human MEC.

Methods

Newborn mouse submandibular glands (SMGs) were incubated with 1 × 10⁵ PFU/ml of lacZ-tagged mCMV RM427+ on day 0 for 24 hours and then cultured in virus-free media for a total of 6 or 12 days with or without EGFR/ERK inhibitors and/or aciclovir. SMGs were collected for histology, immunolocalization (pERK, FN, IL-6), viral distribution, or Western blot analysis (pERK).

Results

Here we report: (1) mouse SMG tumors soon exhibit an acquired resistance to EGFR/ERK pathway kinase inhibitors, alone or in combination; (2) long term tumor regression can only be sustained by concurrent inhibitor and antiviral treatment; (3) CMV-dependent, kinase inhibitor resistance is associated with overexpression of fibronectin and IL-6 proteins in abnormal stromal cells.

Conclusions

Acquired resistance to kinase inhibitors is dependent upon CMV dysregulation of alternative pathways with downstream effectors common with the targeted pathway, a phenomenon with important therapeutic implications for human MEC of salivary glands.