Margin Analysis: Malignant Salivary Gland Neoplasms of the Head and Neck

Clinicopathological correlation of Cathepsin K expression in salivary gland carcinomas; relation to patients` outcome

BACKGROUND

Salivary gland carcinomas (SGCs) represent various groups of tumors that demonstrate marked diversity in their prognosis owing to different histology and clinical characteristics. One of the poor prognostic indicators is distant metastasis which is considered the major reason for death in SGC patients. Discovering new biomarkers is urgently required to aid in the detection of cancer onset and progression. Cathepsin K (CTSK), the lysosomal cysteine protease has a principal role in cancer invasion and progression through interaction with the tumor microenvironment, degradation of extracellular membrane proteins and destruction of the elastic lamina of blood vessels. In the English literature, little information was present about the role of CTSK in SGCs. The current study aimed to assess the immunohistochemical expression of CTSK in SGCs and correlate its expression to different clinicopathologic parameters.

METHODS

The retrospective study applied to 45 cases of SGCs categorized as high-grade (33 cases) and low-grade SGCs (12 cases) following the criteria of WHO classification (2017) of head and neck tumors. All patients` clinicopathological and follow-up records were retrieved. The following statistical tests were used to study the variance of CTSK expression in SGCs concerning different clinicopathological parameters; Pearson`s Chi-square test, unpaired two-tailed student t-test, One-way ANOVA, and Post Hoc tests. Disease-free survival (DFS) and Overall survival (OS) were calculated and displayed with the Kaplan-Meier strategy and analyzed with the log-rank test. Univariate and multivariate survival analyses were performed with Cox regression. A P-value lesser than 0.05 was considered statistically significant.

RESULTS

Strong CTSK expression was significantly related to high-grade SGCs (P = 0.000), large infiltrating carcinomas (P = 0.000), presence of nodal (P = 0.041) and distant metastasis (P = 0.009), advanced TNM clinical stage (P = 0.000), the incidence of recurrence (P = 0.009), and reduced DFS (P = 0.006). Distant metastasis was the independent predictor for DFS using Cox regression model.

CONCLUSIONS

CTSK has a great role in cancer progression by triggering many signaling pathways. Its level in cancerous tissue is considered an effective index for predicting the severity and prognosis of cancer. Therefore, we indicate its utility as a prognostic tool and therapeutic target for cancer treatment.

TRIAL REGISTRATION

Retrospectively registered.

CD24-gold nanocomposite as promising and sensitive biomarker for cancer stem cells in salivary gland tumors

Cancer stem cells are highly tumorigenic cells in the majority of the tumor that are responsible for the initiation, rapid growth, invasion, metastasis, and therapeutic resistance associated with various human cancers. The aim of this project is to assess a diagnostic and prognostic biomarker for the detection of cancer stem cells in salivary gland tumors using gold nanoparticles that are synthesized and conjugated to CD24 primer to form a CD24-Gold Nanocomposite. Sixty cases were included (29 pleomorphic adenoma, 19 carcinoma ex pleomorphic adenoma, and 12 normal controls). Alterations in biomarker expression between studied groups were analyzed and correlated with clinicopathological characteristics using Fisher's exact and Chi-square tests. ROC and Kaplan-Meier curves were used to validate diagnostic and prognostic values, respectively. This study confirms that CD24-Gold Nanocomposite served as a promising and highly sensitive biomarker in salivary gland tumor diagnosis and prognosis prediction.

[Surgery for parotid gland cancer-controversial and proven aspects]

BACKGROUND

Due to the rarity of primary parotid malignancies, there are currently only limited clinical study data on the optimal surgical therapy. Parotid malignancies encompass a broad spectrum of more than 20 different histological subtypes with varying biology, which thus represents a challenge for even experienced pathologists and head and neck surgeons with proven expertise in salivary gland surgery.

OBJECTIVE

The aim of this review article is to provide an overview of the current literature on surgical therapy of the primary tumor and the cN0 neck as well as treatment of the facial nerve, and to shed light on the various controversial aspects of this topic.

RESULTS

In salivary gland oncology there is a trend towards safe (R0) but more conservative surgery. Currently, less-invasive surgical approaches could potentially be applied in a small subgroup with carefully selected caudally located and R0-resected "low-grade tumors" in stages T1-T2 and cN0 in relatively young patients with high compliance and more in the context of structured clinical studies. Elective neck dissection in the case of cN0 status should be carried out if risk factors for occult cervical lymph node metastasis (T3-T4a, "high-grade subtypes," advanced age, lymphangitic carcinomatosis) are present. In cases of small "low-grade parotid carcinomas," narrow resection margins or even microscopic tumor residues on the facial nerve can potentially be adequately compensated with adjuvant radiation therapy. However, due to the lack of solid data, the significance of the actual effect of the radiation in this situation should be viewed with great caution.

Management of Malignant Salivary Gland Conditions

Salivary cancers are rare tumors that arise in major and minor salivary glands. Workup almost always includes fine-needle aspiration or core needle biopsy in select cases. Imaging with ultrasound, computed tomography, or MRI is also helpful, particularly with MRI to assess facial nerve involvement or skull base involvement. Preserving function of the facial nerve is of paramount importance, and the standard of care is to not sacrifice facial nerve except in instances of gross encasement and inability to dissect tumor off of the nerve. Adjuvant radiation and chemotherapy offer survival advantages for select patients.

Evaluation of Surgical Margin Status in Patients With Salivary Gland Cancer

Importance

Salivary gland cancer comprises a diverse group of histologic types with different biological behavior. Owing to this heterogeneity, the association of margin status and postoperative adjuvant radiotherapy has been poorly studied.

Objective

To examine the association between surgical margin status and oncologic outcomes and the subsequent outcome of adjuvant radiotherapy in patients with salivary gland carcinomas.

Design, Setting, and Participants

This cohort study analyzed data from institutional records at Memorial Sloan Kettering Cancer Center from 1985 to 2015. Statistical analysis was completed on October 31, 2020. After exclusions, 837 patients with surgically treated salivary gland carcinoma were identified. Surgical margins and histologic characteristics identified from pathology reports were recorded, with margins classified as negative, close, and positive, and individual histologic types classified into 3 risk groups: low, intermediate, and high.

Exposures

The outcome of adjuvant radiotherapy was determined in patients with close margins with low- and intermediate-risk histologic type and overall pathologic stage I/II disease.

Main Outcomes and Measures

Disease-specific survival (DSS) and local recurrence-free survival (LRFS) outcomes were calculated using the Kaplan-Meier method. Multivariable analysis was performed using the Cox proportional hazards regression model. A planned subgroup analysis of patients with close margins was conducted.

Results

Among the 837 patients identified, 438 were women (52.3%); median age at surgery was 58 years (range, 6-98). A total of 399 tumors (47.7%) originated from major salivary glands, and 438 (52.3%) from minor salivary glands. Margin positivity rates were not different between minor and major salivary gland tumors. Positive surgical margins were identified in 252 patients (30.1%), with nasal cavity/paranasal sinuses and trachea/larynx subsites as the most common sites. Close margins were recorded in 203 patients (24.3%). Adjuvant radiotherapy was administered in 80.5% (103 of 128) of patients with major salivary gland cancer with positive margins, 58.8% (60 of 102) with close margins, and 30.7% (52 of 169) with negative margins and in 70.2% (87 of 124), 36.6% (37 of 101) , and 19.7% (42 of 213) patients with minor salivary gland cancer. With median follow up time of 57 months (range, 1-363 months), patients with positive margins had poorer DSS and LRFS. However, after controlling for overall stage, histologic risk group, and adjuvant radiotherapy, margin status was not a factor associated with poorer DSS or LRFS. In patients with close margins, low-risk and intermediate-risk histologic type, and overall pathologic stage I/II, patients who did not have adjuvant radiotherapy had comparable local control with those who received adjuvant radiotherapy.

Conclusions and Relevance

The findings of this cohort study suggest that patients with salivary gland cancer who have either close or positive surgical margins are at increased risk for poorer local control and survival. After controlling for tumor stage, histologic risk group, and the use of adjuvant radiotherapy, margin status was not an independent factor associated with poorer outcome. Subgroup analyses showed that care for patients with close margins with low-risk or intermediate-risk histologic type who have stage I/II cancers might be managed safely without adjuvant radiotherapy.

CXCR5 induces perineural invasion of salivary adenoid cystic carcinoma by inhibiting microRNA-187

CXCR5 played critical roles in tumorigenesis and metastasis. Nevertheless, little was known about the involvement of CXCR5 in perineural invasion (PNI) of salivary adenoid cystic carcinoma (SACC). Here, we confirmed upregulation of CXCR5 in SACC specimens and cells and identified that CXCR5 exhibited a significant positive correlation with PNI. Functionally, knockdown of CXCR5 suppressed SACC cells migration, invasion and PNI ability, whereas CXCR5 overexpression displayed the opposite effects. Moreover, CXCR5 downregulated microRNA (miR)-187, which could competitively sponge S100A4. The PNI-inhibitory effect of CXCR5 knockdown or miR-187 overexpression could be reversed by elevated expression of S100A4. Conjointly, our data revealed that CXCR5 facilitated PNI through downregulating miR-187 to disinhibit S100A4 expression in SACC.

Inhibition of DEC2 is necessary for exiting cell dormancy in salivary adenoid cystic carcinoma

Background

Patients were prone to have poor prognosis once dormant tumor cells being reactivated. However, the molecular mechanism of tumor cell dormancy remains poorly understood. This study aimed to investigate the function of DEC2 in the dormancy of salivary adenoid cystic carcinoma (SACC) in vitro and vivo.

Methods

The function of DEC2 in tumor dormancy of SACC was investigated in nude mice by establishing primary and lung metastasis model. Meanwhile, the interaction between hypoxia and SACC dormancy and the role of DEC2 were demonstrated through CoCl₂ induced hypoxia–mimicking microenvironments. Furthermore, the expression of DEC2 was detected by immunohistochemical staining in primary SACC samples with and without recurrence.

Results

In the primary SACC, DEC2 overexpression inhibited cell proliferation, increased cell population arrested in G0/G1 phase, and participated in dormancy regulation, which limited tumor growth. Intriguingly, in the model of lung metastasis, the level of DEC2 was reduced significantly and resulted in dormancy exit and growth resumption of SACC cells. Then, we found that DEC2 may associate with hypoxia in contributing to tumor dormancy, which might provide a possible cue to explain the different roles of DEC2 in primary and metastasis lesions. And overexpression of DEC2 induced dormancy and promoted migration and invasion through activating EMT program. Finally, DEC2 positive expression was shown to be significantly correlated with recurrence and dormancy of SACC patients.

Conclusions

These findings provide a novel insight into the role of DEC2 gene in tumor dormancy and metastasis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01956-0.

Clinical target volume design of postoperative intensity-modulated radiotherapy for major salivary gland tumours according to surgical principles: an innovative method

BACKGROUND

No international consensus has been reached regarding delineation of postoperative intensity-modulated radiotherapy (PO-IMRT) clinical target volumes (CTV) for major salivary gland carcinoma (SGC). The purpose of this article was to report our experience according to surgical principles.

METHODS

Between June 2010 and June 2018, 54 consecutive patients were enrolled. Reserved tissues around the margin of resection that were less than 5 mm from the invasive tumour edge before surgery were defined as high-risk clinical target volumes (CTV-HD), those less than 10 mm away were defined as medium-risk CTV (CTV1), and those 10-20 mm away were defined as low-risk CTV (CTV2), and were irradiated with 63-65 Gy, 59.5-61 Gy, and 45-54 Gy, respectively. Target volume distributions of reserved tissues were analysed and actuarial estimates of overall survival (OS), recurrence-free survival (RFS) and distant metastasis-free survival (DMFS) were obtained with the Kaplan-Meier method.

RESULTS

In parotid gland tumours, the percentages of defined CTV-HD in the styloid process, mandibular ramus, posterior venter of the digastric muscle, carotid sheath and stylomastoid foramen reached 34.29%, 25.71%, 54.29%, 40.00%, and 37.10%, respectively. The median follow-up was 33 months (range, 5-98 months). The 3-year and 5-year Kaplan-Meier estimates of OS, RFS and DMFS were 85.4% and 77.8%, 97.4%, and 97.4%, and 82.0% and 82.0%, respectively.

CONCLUSIONS

It is feasible to delineate CTVs according to distances between various reserved tissues and the primary tumour edge before operation.

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.

Analysis of the clinicopathological characteristics and prognosis of adenoid cystic carcinoma of the intraoral minor salivary glands: a retrospective study of 40 cases

The clinicopathological aspects and prognostic factors of 40 patients with adenoid cystic carcinoma (ACC) of the intraoral minor salivary glands, treated between 2007 and 2017 at a single institution, were evaluated retrospectively. Twenty-six were female and 14 were male, and they ranged in age from 26 to 81 years (median 55 years). ACC occurred mainly in the palate, with 54.8% of cases presenting T3-T4 lesions. Curative surgery was performed in all patients, and 62.5% of patients were treated with postoperative adjuvant radiotherapy. In the final analysis, positive surgical margins were noted in 57.5% of cases and perineural invasion in 70%. Follow-up was at least 13 months (range 13-141 months, median 59 months). Nineteen patients (47.5%) developed recurrent disease after initial surgery and nine patients had died at the end of follow-up. The 5- and 10-year overall survival rates were 88.3% and 25.6%, respectively. The 5- and 10-year disease-free survival rates were 75.6% and 34.0%, respectively. Patients with a tumour size >4cm and those with positive surgical margins showed a significantly higher risk of local recurrence. Elective neck dissection is suggested for patients with clinically positive lymph nodes or a locally advanced tumour, especially those undergoing microvascular reconstruction. The survival analysis results are similar to those reported previously in the literature.

NR2F1 contributes to cancer cell dormancy, invasion and metastasis of salivary adenoid cystic carcinoma by activating CXCL12/CXCR4 pathway

BACKGROUND

Salivary adenoid cystic carcinoma (SACC) can recur after removal of the primary tumor and treatment, where they can keep no clinical symptoms and dormant state for 10-15 years. NR2F1 has been demonstrated to regulate the tumor cell dormancy in various malignant tumors and has a potential impact on recurrence and metastasis of carcinoma. However, the role and significance of NR2F1 in SACC dormancy still remain unknown.

METHODS

A total number of 59 patients with a diagnosis of SACC were included to detected expression of NR2F1, Ki-67 by immunohistochemical (IHC) staining and terminal deoxynucleotidyl transferase-mediated dUTP nick and labeling (TUNEL). Fisher's exact test was used to examine the NR2F1 expression and clinicopathologic parameters of SACC. In vitro, SACC cell lines were transfected NR2F1 and knockdown NR2F1 respectively. CCK-8, flow cytometry, wound healing assay and transwell invasion determined SACC cell proliferation, apoptosis, cell cycle, migration and invasion respectively. Chromatin immunoprecipitation (ChIP) assays were utilized to demonstrate the potential role of NR2F1 in SACC invasion via CXCL12/CXCR4 axis. In vivo, xenografts of nude mice via subcutaneous injection or tail vein injection were used to testify the results in vitro.

RESULTS

Among the 59 patients with SACC, 23.73% (14/59) were positive to NR2F1 expression, a lower rate of expression compared with 60% (6/10) in normal salivary gland samples. NR2F1 was correlated with metastasis, relapse and dormancy of SACC. SACC cells with transfected NR2F1 remained dormant, as well as enhanced invasion and metastasis. Knockdown of NR2F1 via siRNA after NR2F1 overexpression restored the proliferation and the cell number in G2/M phases, and reduced the abilities of migration and invasion. In addition, NR2F1 promoted the expression of CXCL12 and CXCR4, and overexpression of CXCL12 at least partly rescued the proliferation, migration, and invasion activities induced by NR2F1 silencing.

CONCLUSIONS

NR2F1 may be an underlying mechanism of SACC recurrence and metastasis via regulating tumor cell dormancy through CXCL12/CXCR4 pathway.

Positive Surgical Margins in Submandibular Malignancies: Facility and Practice Variation

OBJECTIVES

Identify positive margin rate in a national cohort of patients with submandibular carcinoma, identify predictors of positive margins, and associate margins with overall survival.

STUDY DESIGN

Retrospective cohort.

SETTING

Commission on Cancer-accredited hospitals.

SUBJECTS AND METHODS

We included patients in the National Cancer Database from 2004 to 2014 who were diagnosed with submandibular carcinoma and underwent primary surgical resection. We determined the rate of positive surgical margins and associated patient, tumor, and treatment factors with positive margins via univariable and multivariable logistic regression analysis. We associated margin status with overall survival by Kaplan-Meier curve and Cox proportional hazards regression.

RESULTS

We identified 1150 patients with submandibular malignancy undergoing surgical resection. Positive margin rate was 41.0%. Increased odds of positive margins were seen in patients with advanced T stage (vs T1, T3: odds ratio [OR] = 3.04, P < .001; T4a: OR = 2.89, P < .001), adenoid cystic carcinoma histology (OR = 1.54, P = .020), and those treated at nonacademic facilities (OR = 1.41, P = .008). Patients who underwent a preoperative diagnostic biopsy had decreased odds of positive margins (OR = 0.72, P = .014). Positive margins were associated with reduced overall survival (58% vs 69% 5-year overall survival, P < .001; hazard ratio = 1.49, P = .001) when controlling for patient, tumor, and management factors.

CONCLUSIONS

The national positive margin rate of submandibular carcinoma is 41.0%. Preoperative biopsy and treatment at academic institutions independently decreased the risk of positive margins, and positive margins were independently associated with diminished overall survival. Positive margin rate for submandibular carcinoma may be considered a benchmark for quality of care.

Salivary Gland Malignancies

Salivary gland tumors are rare pathologic entities that are derived from major and minor salivary gland tissue located throughout the head and neck region. These tumors are distinctly heterogenous, comprising numerous cell types, especially those deemed malignant. The incidence of malignant salivary gland tumors is widely distributed in both adult and pediatric patient populations. Accurate diagnosis and optimal treatment of these tumors pose challenges to both interpreting pathologists and ablative surgeons. This article examines the epidemiology and pathology of malignant tumors of the major and minor salivary glands and provides recommendations for the most successful treatment approaches.