Systemic therapy for salivary gland malignancy: current status and future perspectives

Current diagnosis and treatment of salivary gland-type tumors of the lung

Salivary gland-type tumors of the lung are thought to originate from the submucosal exocrine glands of the large airways. Due to their rare occurrence, reports of their study are limited to small-scale or case reports. Therefore, daily clinical practices often require a search for previous reports. In the last 20 years, several genetic rearrangements have been identified, such as MYB::NF1B rearrangements in adenoid cystic carcinoma, CRTC1::MAML2 rearrangements in mucoepidermoid carcinoma, EWSR1::ATF1 rearrangements in hyalinizing clear cell carcinoma and rearrangements of the EWSR1 locus or FUS (TLS) locus in myoepithelioma and myoepithelial carcinoma. These molecular alterations have been useful in diagnosing these tumors, although they have not yet been linked to molecularly targeted therapies. The morphologic, immunophenotypic, and molecular characteristics of these tumors are similar to those of their counterparts of extrapulmonary origin, so clinical and radiologic differential diagnosis is required to distinguish between primary and metastatic disease of other primary sites. However, these molecular alterations can be useful in differentiating them from other primary lung cancer histologic types. The management of these tumors requires broad knowledge of the latest diagnostics, surgery, radiotherapy, bronchoscopic interventions, chemotherapy, immunotherapy as well as therapeutic agents in development, including molecularly targeted agents. This review provides a comprehensive overview of the current diagnosis and treatment of pulmonary salivary gland tumors, with a focus on adenoid cystic carcinoma and mucoepidermoid carcinoma, which are the two most common subtypes.

Applications of Intravital Imaging in Cancer Immunotherapy

Currently, immunotherapy is one of the most effective treatment strategies for cancer. However, the efficacy of any specific anti-tumor immunotherapy can vary based on the dynamic characteristics of immune cells, such as their rate of migration and cell-to-cell interactions. Therefore, understanding the dynamics among cells involved in the immune response can inform the optimization and improvement of existing immunotherapy strategies. In vivo imaging technologies use optical microscopy techniques to visualize the movement and behavior of cells in vivo, including cells involved in the immune response, thereby showing great potential for application in the field of cancer immunotherapy. In this review, we briefly introduce the technical aspects required for in vivo imaging, such as fluorescent protein labeling, the construction of transgenic mice, and various window chamber models. Then, we discuss the elucidation of new phenomena and mechanisms relating to tumor immunotherapy that has been made possible by the application of in vivo imaging technology. Specifically, in vivo imaging has supported the characterization of the movement of T cells during immune checkpoint inhibitor therapy and the kinetic analysis of dendritic cell migration in tumor vaccine therapy. Finally, we provide a perspective on the challenges and future research directions for the use of in vivo imaging technology in cancer immunotherapy.

Molecular Factors in Carcinoma Ex Pleomorphic Adenoma: Systematic Review and Meta-Analysis

OBJECTIVE

Carcinoma ex pleomorphic adenoma (CXPA) is a rare malignant salivary gland tumor. Although multiple reviews have been published on salivary gland malignancies, it has been a decade since the last dedicated systematic review pertaining to CXPA alone was published. This study examines molecular factors in CXPA diagnosis.

DATA SOURCES

MEDLINE, CINAHL, Embase, Scopus, Web of Science (BIOSIS), Cochrane CENTRAL, Health Collection (Informit), OpenDOAR, and GreyNet International.

REVIEW METHODS

Systematic review and meta-analysis from inception to October 31, 2022 for all English language studies pertaining to "carcinoma ex pleomorphic adenoma." Predicted incidence of each biomarker was calculated with meta-analysis. Comparison against pleomorphic adenoma (PA) and salivary duct carcinoma (SDC) when reported within the same study are performed. Risk of bias performed with JBI tool for prevalence studies.

RESULTS

Of 19151 unique studies undergoing abstract screening, 55 studies (n = 1322 patients) underwent data analysis. Biomarkers with >3 studies were p53, HER2, AR, EGFR, PLAG1, ERBB, ER, PR, HMGA2, p16, p63, a-SMA, RAS, PTEN, PDL1, BRAF, PIK3CA, and c-kit. Highest incidence was seen in AR, EGFR, p16, and p53. Significant differences were demonstrated compared with PA and SDC. There was high heterogeneity and overall high risk of bias within studies.

CONCLUSION

Molecular factors are an area of interest in the diagnosis of CXPA. Our study results support examining CXPA as a discrete cohort in future targeted therapy trials. Laryngoscope, 134:1042-1053, 2024.

The neutrophil-to-lymphocyte ratio in salivary gland cancers treated with pembrolizumab

BACKGROUND

A minority of patients with recurrent/metastatic (R/M) salivary gland cancers (SGCs) benefit from immune checkpoint inhibitors (ICIs), necessitating reliable biomarkers for ICI response prediction.

METHODS

Retrospective observational study of R/M SGC patients treated with pembrolizumab between 2016 and 2022, with a primary outcome of 6-month progression-free survival (PFS) and secondary outcome of 2-year overall survival (OS). Univariate and multivariable Cox proportional hazards models were employed.

RESULTS

Twenty R/M SGC patients were included. After adjustment, NLR as a continuous variable was independently associated with 6-month PFS (HR 1.30, 95% CI 1.10-1.54, p = 0.002) and 2-year OS (HR 1.33, 95% CI 1.07-1.66, p = 0.010). Similarly, NLR ≥ 5 was associated with higher hazards of progression at 6 months (HR 12.85, 95% CI 2.17-76.16, p = 0.005) and death at 2 years (HR 11.25, 95% CI 1.67-75.77, p = 0.013).

CONCLUSIONS

Higher pretreatment NLR was independently associated with inferior 6-month PFS and 2-year OS in pembrolizumab-treated R/M SGC patients.

Current management and future challenges in salivary glands cancer

Salivary gland cancers (SGCs) are rare, accounting for less than 5% of all malignancies of the head and neck region, and are morphologically heterogeneous. The diagnosis is mainly based on histology, with the complementary aid of molecular profiling, which is helpful in recognizing some poorly differentiated, borderline, or atypical lesions. Instrumental imaging defines the diagnosis, representing a remarkable tool in the treatment plan. Ultrasound and magnetic resonance are the most common procedures used to describe the primary tumour. The treatment of SGCs is multimodal and consists of surgery, radiotherapy, and systemic therapy; each treatment plan is, however, featured on the patient and disease's characteristics. On 24 June 2022, in the meeting "Current management and future challenges in salivary gland cancers" many experts in this field discussed the state of the art of SGCs research, the future challenges and developments. After the meeting, the same pool of experts maintained close contact to keep these data further updated in the conference proceedings presented here. This review collects the insights and suggestions that emerged from the discussion during and after the meeting per se.

Combination chemotherapy with taxane and platinum in patients with salivary gland carcinoma: a retrospective study of docetaxel plus cisplatin and paclitaxel plus carboplatin

Background

Despite advances in precision medicine, most patients with recurrent or metastatic salivary gland carcinoma still need conventional chemotherapies, such as the combination of taxane and platinum. However, evidence for these standardized regimens is limited.

Methods

We retrospectively reviewed patients with salivary gland carcinoma treated with a taxane and platinum, which contained docetaxel at a dose of 60 mg/m2 plus cisplatin at a dose of 70 mg/m2 on day 1, or paclitaxel at a dose of 100 mg/m2 plus carboplatin at a dose of area under the plasma concentration-time curve = 2.5 on days 1 and 8 (both on 21-day cycles), between January 2000 and September 2021.

Result

Forty patients with ten adenoid cystic carcinomas and thirty other pathologies were identified. Of these, 29 patients were treated with docetaxel plus cisplatin and 11 with paclitaxel plus carboplatin. For the total population, the objective response rate (ORR) and median progression-free survival (mPFS) were 37.5% and 5.4 months (95% confidence interval: 3.6-7.4 months), respectively. On subgroup analysis, docetaxel plus cisplatin provided favorable efficacy compared with paclitaxel plus carboplatin (ORR: 46.5% vs. 20.0%, mPFS: 7.2 vs. 2.8 months), and the findings were well retained in patients with adenoid cystic carcinoma (ORR: 60.0% vs. 0%, mPFS: 17.7 vs. 2.8 months). Grade 3/4 neutropenia was relatively frequent in the docetaxel plus cisplatin (59% vs.27%), although febrile neutropenia was uncommon (3%) in the cohort. No treatment-related death was seen in any case.

Conclusion

The combination of taxane and platinum is generally effective and well-tolerated for recurrent or metastatic salivary gland carcinoma. In contrast, paclitaxel plus carboplatin appears unfavorable in terms of efficacy in certain patients, such as those with adenoid cystic carcinoma.

[Special tumor entities in the head and neck region: nasopharyngeal, salivary gland, and thyroid cancer]

BACKGROUND

At the meetings of the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO) in 2022, studies were presented which suggest changes in the clinical routine of nasopharyngeal, salivary gland, and thyroid cancer.

OBJECTIVE

Therapeutic innovations for special otorhinolaryngological tumor entities with potential clinical relevance were assessed after reviewing the studies presented at the ASCO 2022/ESMO 2022 meetings.

MATERIALS AND METHODS

The presented clinical phase II and phase III studies were analyzed. Results were classified according to their potential clinical importance, taking into account current treatment standards.

RESULTS

Three studies were presented that dealt with the topic of risk-adapted treatment stratification in advanced nasopharyngeal cancer. Dose-reduced radiotherapy (60 Gy) in low-risk patients resulted in a favorable toxicity profile with promising oncological results in a single-arm phase II study. In a phase III study, intensity-modulated radiotherapy alone showed comparable survival to combined radiochemotherapy with cisplatin in selected low-risk patients. In high-risk patients, addition of the EGFR antibody nimotuzumab to definitive radiochemotherapy showed an increased 5‑year survival rate compared to placebo (phase III study). Although an immediate change in clinical practice in Europe based on these studies is questionable, the concept of risk-adapted therapy taking into account biological characteristics (Epstein-Barr virus [EBV] DNA level) is future orientated. Similar to previous years, the contributions on recurrent/metastatic salivary gland and thyroid cancer emphasized the importance of targeted therapies based on vulnerable molecular target lesions.

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.

Adenoid Cystic Carcinoma (AdCC): A Clinical Survey of a Large Patient Cohort

Adenoid cystic carcinoma (AdCC), a rare heterogenous disease, presents diagnostic, prognostic, and therapeutic challenges. To obtain more knowledge, we conducted a retrospective study on a cohort of 155 patients diagnosed in 2000-2022 with AdCC of the head and neck in Stockholm and investigated several clinical parameters in correlation to treatment and prognosis in the 142/155 patients treated with curative intent. The strongest favourable prognostic factors were early disease stage (stage I and II) as compared to late disease (stage III and IV) and major salivary gland subsite as compared to other subsites, with the best prognosis in the parotid gland, irrespective of the stage of the disease. Notably, in contrast to some studies, a significant correlation to survival was not found for perineural invasion or radical surgery. However, similar to others, we confirmed that other common prognostic factors, e.g., smoking, age, and gender, did not correlate to survival and should not be used for prognostication of AdCC of the head and neck. To conclude, in AdCC early disease stage, major salivary gland subsite and multimodal treatment were the strongest favourable prognostic factors, while this was not the case for age, gender and smoking nor perineural invasion and radical surgery.

Prognostic Assessment and Risk Stratification in Patients With Postoperative Major Salivary Acinar Cell Carcinoma

OBJECTIVE

To investigate the clinicopathological features and prognosis of postoperative major salivary acinar cell carcinoma (MSACC) and develop a prognostic model.

STUDY DESIGN

Retrospective cohort analysis of a public database.

SETTING

Patients with MSACC were identified from the Surveillance, Epidemiology, and End Results database (1975-2019).

METHODS

Overall survival (OS) was evaluated using Kaplan-Meier curves and a log-rank test. Univariate and multivariate Cox analyses were performed to explore independent prognostic factors. The prognostic model was constructed using screened variables and further visualized with a nomogram and web calculator, and assessed by concordance index, the area under the curve, calibration curve, and decision-making curve analysis.

RESULTS

An upward trend in the incidence of MSACC was observed throughout the study period. A total of 1398 patients were enrolled (training cohort: 978; validation cohort: 420), and the 5- and 10-year OS rates were 97.7% and 81.6%, respectively. Age, marital status, sex, histological grade, T stage, and lymph node status were identified as prognostic factors for OS. A novel nomogram was developed and showed excellent discrimination and clinical applicability. Additionally, a web calculator was designed to dynamically predict patient survival. Based on the nomogram-based score, a risk stratification system was constructed to distinguish patients with different risks. The OS of high-risk patients was significantly lower than that of the low-risk subgroup.

CONCLUSION

Long-term survival in postoperative MSACC was influenced by 6 prognostic factors. The proposed model enables individualized survival prediction and risk stratification, prompting us to be vigilant in high-risk subgroups and consider timely adjustment of subsequent treatment.

Adoption of adjuvant chemotherapy in high-risk salivary gland malignancies

BACKGROUND

The present study characterizes national trends in the utilization of adjuvant chemotherapy to treat salivary gland malignancies.

METHODS

The National Cancer Database was queried for salivary gland malignancies treated by surgery with radiation in 2004-2019. Proportions of patients receiving adjuvant chemotherapy over the study period were analyzed by linear regression. The impact of chemotherapy on overall survival was assessed using Kaplan-Meier and Cox proportional hazards analyses.

RESULTS

Among 15 965 patients meeting inclusion criteria, 2355 (14.8%) received adjuvant chemotherapy. Chemotherapy utilization significantly increased from 4.9% to 16.5% over the study period (p < 0.001). No survival benefit was observed with adjuvant chemotherapy on propensity score-matched Kaplan-Meier analysis (HR: 0.98; 95% CI: 0.86-1.11; p = 0.72) or multivariable Cox regression (HR: 0.92; 95% CI: 0.78-1.09; p = 0.34).

CONCLUSIONS

Adjuvant chemotherapy has been increasingly utilized to treat salivary gland malignancies in recent years. Our findings highlight the importance of obtaining high-quality prospective data regarding the benefit of chemotherapy.