Cytology and histology have limited added value in prognostic models for salivary gland carcinomas

Prognostic scoring models in parotid gland carcinoma

BACKGROUND

The aim was to identify prognostic factors and test three prognostic scoring models that predicted the risk of recurrence in patients with parotid gland carcinoma.

METHODS

All Danish patients with parotid gland carcinoma, treated with curative intent, from 1990 to 2015 (n = 726) were included. Potential prognostic factors were evaluated using Cox regression and competing risk analyses. The concordance of each prognostic model was estimated using Harrel's C index.

RESULTS

The study population consisted of 344 men and 382 women, with a median age of 63 years. Age above 60 years, high grade histology, T3/T4 tumor, regional lymph node metastases, and involved surgical margins were all associated with a significant reduction in recurrence-free survival. The prognostic model that agreed best with actual outcomes had a C-index of 0.76.

CONCLUSION

Prognostic scoring models may improve individualized follow-up strategies after curatively intended treatment for patients with parotid gland carcinoma.

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.

Salivary Duct Carcinoma of the Parotid: Outcomes with a Contemporary Multidisciplinary Treatment Approach

OBJECTIVE

Salivary duct carcinoma (SDC) is a rare and aggressive malignancy for which an optimal treatment algorithm is lacking. We endeavored to assess the current treatment outcomes for SDC with a multimodality treatment approach combining surgery with adjuvant radiotherapy ± concurrent chemotherapy.

STUDY DESIGN

Case series with chart review.

SETTING

A National Cancer Institute-designated comprehensive cancer center.

SUBJECTS AND METHODS

The clinical record of 17 patients with salivary duct carcinoma were analyzed to assess locoregional control, recurrence-free survival, and overall survival.

RESULTS

All SDC cases (n = 17) were managed with surgical resection, followed by adjuvant radiotherapy (47.1%) or concurrent chemotherapy and radiotherapy (52.9%). Median patient follow up was 37 months. An aggressive disease course was generally observed, with 3-year recurrence-free survival and overall survival of 34.4% and 35.5%, respectively. The majority of recurrences were distant. Intensification with adjuvant concurrent chemotherapy was not associated with improved outcomes on univariate survival analysis.

CONCLUSION

For salivary duct carcinoma, a multimodality treatment approach is associated with acceptable locoregional control rates but poor distant control and overall survival. Novel systemic therapies may be needed to optimize clinical outcomes.

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.

[Salivary gland tumors: pathology and prognosis]

Due to their infrequency, diagnosis of salivary gland tumors remains a challenge for the practicing pathologist with respect to subtyping, grading and estimating patient prognosis. In a 3 center collaborative study of 288 cases with clinical follow-up information, it could be demonstrated that apart from clinical parameters like high patient's age, male sex and high tumor stage, the application of a 3-tiered grading system incorporating the histological tumor type is of high prognostic relevance. In immunohistochemical and molecular analyses overexpression of epidermal growth factor receptor (EGFR), high expression of human epidermal growth factor receptor 2 (HER2), amplification and gains of EGFR and HER2, absent expression of C-KIT, loss of maspin and of O(6)-methylguanine DNA-methyltransferase (MGMT) as well as MGMT promoter methylation turned out to be negative prognostic factors. In mucoepidermoid carcinomas the presence of a translocation t(11;19) was less relevant than recognizing different subtypes (classical type, eosinophilic, clear-cell and squamoid variants). Acinic cell carcinoma with mixed acinar-ductular differentiation as judged by expression of CK7 was characterized by a higher frequency of early relapse. The presented results underline the pathologist's role in the diagnosis and management of patients with salivary gland carcinomas.