A molecular guide to systemic therapy in salivary gland carcinoma

Association of chromosomal aberrations in chromosomes 3 and 7, and P16 mutations with malignancy in salivary gland tumors

Background

Salivary gland tumors, a prevalent type of head and neck neoplasm, exhibit significant morphological diversity and overlapping features, complicating pathological diagnosis. Although fluorescence in situ hybridization (FISH) is widely used for tumor detection, its diagnostic utility in salivary gland tumors remains unclear. This study aimed to explore a novel FISH-based approach to differentiate benign from malignant salivary gland tumors.

Methods

Gene probes (CSP3, CSP7, and GSP P16) were designed to detect P16 gene deletion, and polysomies of chromosomes 3 and 7. The FISH analysis was conducted on 22 malignant and 12 benign salivary gland tumor samples with complete clinical data. The study was expanded to 78 samples for further validation.

Results

The CSP3, CSP7, and GSP P16 probes exhibited high specificity for salivary gland tumors, though CSP7 exhibited lower sensitivity. The combination of CSP3 and GSP P16 probes outperformed single-probe analysis or other probe combinations.

Conclusion

The CSP3 and GSP P16 probe combination provides a highly sensitive and specific method for distinguishing malignant from benign salivary gland tumors.

Comparison of 64Cu-DOTA-PSMA-3Q and 64Cu-NOTA-PSMA-3Q utilizing NOTA and DOTA as bifunctional chelators in prostate cancer: preclinical assessment and preliminary clinical PET/CT imaging

OBJECTIVE

This study aims to investigate the efficacy and safety of prostate-specific membrane antigen (PSMA) radiolabeled with copper-64 (64Cu) using the bifunctional chelating agents (BFCAs) NOTA (1,4,7-triazacyclononane-1,4,7-triacetic acid) and DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid). As widely utilized BFCAs in the development of radiopharmaceuticals, NOTA and DOTA play a critical role in ensuring stable chelation with 64Cu. This study evaluates the stability, bioavailability, and therapeutic potential of these radiolabeled compounds in preclinical models and initial clinical trials.

METHODS

64Cu-DOTA-PSMA-3Q and 64Cu-NOTA-PSMA-3Q were synthesized by manual labeling. The radiochemical purity, stability, specificity and biological distribution of the product were evaluated by preclinical studies. In 23 patients with suspected prostate cancer, PET/CT imaging was used to evaluate the potential and differences in biological distribution of 64Cu-DOTA-PSMA-3Q and 64Cu-NOTA-PSMA-3Q in clinical diagnosis.

RESULTS

The radiochemical purities of 64Cu-DOTA-PSMA-3Q and 64Cu-NOTA-PSMA-3Q are more than 98% and have good stability in vitro. Biodistribution studies in healthy mice revealed that both tracers primarily underwent renal excretion post-injection. Liver uptake of 64Cu-DOTA-PSMA-3Q was significantly higher than that of 64Cu-NOTA-PSMA-3Q at 1 h after injection (P<0.05). Micro-PET/CT imaging in 22Rv1 tumor-bearing mice demonstrated similar tumor uptake for both tracers at 1 h after injection (P>0.05). However, after 24 h, 64Cu-DOTA-PSMA-3Q exhibited significantly better tumor retention compared to 64Cu-NOTA-PSMA-3Q (P<0.05). In clinical PET/CT imaging involving 23 patients with suspected prostate cancer, no adverse reactions or significant changes in vital signs were observed, underscoring the safety of both tracers. Notably, 64Cu-NOTA-PSMA-3Q demonstrated higher uptake in the lacrimal glands (17.73 vs. 10.84), parotid glands (20.98 vs. 16.30), and submandibular glands (20.26 vs. 17.28) compared to 64Cu-DOTA-PSMA-3Q. Conversely, uptake in the sublingual glands was lower for 64Cu-NOTA-PSMA-3Q (7.10 vs. 7.49). Of particular clinical relevance, liver uptake of 64Cu-NOTA-PSMA-3Q was significantly lower than that of 64Cu-DOTA-PSMA-3Q (4.04 vs. 8.18), highlighting a key difference in their biodistribution profiles.

CONCLUSIONS

Both NOTA and DOTA are suitable chelators for the development of 64Cu-labeled PSMA-3Q tracers for PET/CT imaging. DOTA showed better tumor retention 24 h after injection, while NOTA showed lower uptake in the liver, in addition, NOTA was higher uptake in the salivary glands, while DOTA was lower uptake in these tissues. Overall, these findings highlight the importance of selecting the right chelating agent to optimize clinical imaging outcomes.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ChiCTR2300072655, Registered 20 June 2023.

[Clinical and molecular epidemiology of malignant salivary gland tumors]

Salivary gland carcinomas are a rare and heterogeneous group of malignant tumors, accounting for 3-6% of all malignant tumors in the head and neck region. The 1-, 3- and 5-year survival rates are 83%, 69% and 63% respectively. Due to new molecular pathological and genetic findings, new entities are constantly being defined as part of the recurring WHO classification of salivary gland carcinomas, so that the incidence rates of the entities are subject to constant change. The only certain risk factor for the development of salivary gland carcinomas is ionizing radiation. In addition, large tumors, cervical lymph node involvement and perineural sheath involvement significantly worsen the prognosis. Today, molecular pathology is coming to the fore, with which potential targets have been identified that can offer prognosis-improving treatment options, particularly in recurrent or distant metastatic stages. Entity-specific tyrosine kinase inhibitors such as axitinib in adenoid cystic carcinoma or larotrectinib in secretory carcinoma and cross-entity therapies such as HER2 inhibition and androgen deprivation can prolong median and progression-free survival with a favorable side effect profile.

Targeted Therapy in Salivary Gland Cancer: Prevalence of a Selected Panel of Actionable Molecular Alterations in a German Tertiary Referral Center Patient Cohort

OBJECTIVE

Salivary gland carcinomas (SGC) are a heterogeneous group of malignancies, with 24 subtypes defined by the World Health Organization (WHO). The standard of therapy is surgical resection, with adjuvant radiotherapy in most cases. However, disease recurrence (R) or metastasis (M) is common and no active systemic therapies are currently available for RM-SGC resulting in a 5-year survival rate of only 20%.

PATIENTS AND METHODS

Overall, 55 SGC patients with seven different histological tumor subtypes were included in this study. formalin-fixed paraffin-embedded (FFPE) tissue samples were used for immunohistochemical (IHC) staining targeting HER2/neu, androgen receptor (AR), PD-L1, EGFR, panTRK, and TROP2. Fluorescence in situ hybridization (FISH) was performed for detecting HER2/neu amplifications and NTRK1/2/3 translocations in selected cases with relevant HER2/neu and panTRK protein expression, respectively. IHC and FISH results were correlated with patients' clinical and histopathological data.

RESULTS

The overall prevalence of druggable molecular alterations, defined as an immunoreactive score ≥ 9 in at least one of the analyzed targets, was 54.4% with the highest percentage in oncocytic carcinomas (100%) and lowest percentage in acinic cell carcinomas (10%). EGFR overexpression proved to be the most common alteration (32.7% of cases) followed by overexpression of TROP2 (27.3%), AR (10.9%), HER2/neu (7.3%), PD-L1 (1.8%), and panTRK (1.8%). HER2/neu amplifications were found in 50% and NTRK translocations were found in 100% of all cases with elevated Her2/neu and panTRK protein expression, respectively.

CONCLUSIONS

Our data indicate that targeted therapy using e.g., trastuzumab deruxtecan, bicalutamide, pembrolizumab, cetuximab, entrectinib or sacituzumab govitecan might be a promising option especially for a relevant subset of patients with RM-SGC not suitable for salvage surgery. However, evidence from clinical studies regarding response rates to these therapies remains sparse, which underlines the need of multicenter clinical trials.

Malignant Salivary Gland Tumors in a Tertiary University Hospital in Northern Spain

(1) Background: Salivary gland tumors (SGTs) are a rare and diverse group of neoplasms arising in the parotid, submandibular, sublingual, and minor salivary glands distributed throughout the upper aerodigestive tract. Given the rarity and complexity of MSGTs, understanding their epidemiology across diverse populations is crucial for improving diagnostic and therapeutic strategies. (2) Methods: A retrospective analysis involving 45 patients diagnosed with malignant salivary gland tumors and treated with curative intention between 1 July 2016 and 1 July 2021 in a tertiary academic hospital was performed. (3) Results: Histologically, the most common subtype was adenoid cystic carcinoma in 12 (26.7%) cases, followed by carcinoma ex-pleomorphic adenoma in 7 (15.6%) cases, mucoepidermoid carcinoma in 6 (13.3%) cases, and adenocarcinoma in 6 (13.3%) cases. The majority of tumors were located in the parotid gland in 28 cases (62.2%). The three-year overall survival rate was 80% and the three-year specific survival rate was 86.7%. Tumor grade was significantly associated with local recurrence and the appearance of distant metastasis during the follow-up period (p = 0.04). We also evidenced a worse survival in patients with advanced T-Stage (p = 0.038) and positive nodes in the neck (p = 0.015). (4) Conclusions: Overall, our study reinforces the prognostic significance of tumor grade, T-Stage and N-Stage while challenging the conventional understanding of factors such as PNI, LNM, and margin status.

High-grade salivary carcinomas: A current insight on diagnostic pathology and the key to clinical decision making

High-grade carcinomas of the salivary glands are a group of several tumor entities with highly malignant histologic appearances, and have an aggressive biological behavior accompanied by poor a prognosis. In general, they require more intensive treatment than low- or intermediate-grade carcinomas. High-grade salivary carcinomas are rare and the microscopic features often overlap between different tumor types, making an appropriate diagnosis challenging in daily practice settings. However, with recent rapid advances in molecular pathology and molecular-targeted therapy in this field, there is a growing need to properly classify tumors, rather than just diagnosing the cases as "high-grade carcinomas". This leads to specific treatment strategies. In this article, we review representative high-grade salivary gland carcinomas, including salivary duct carcinoma and its histologic subtypes, high-grade mucoepidermoid carcinoma, solid-type adenoid cystic carcinoma, and high-grade transformation of low- or intermediate-grade carcinomas, and discuss their differential diagnoses and clinical implications. Other rare entities, such as neuroendocrine carcinoma, NUT carcinoma, and metastatic carcinoma, should also be considered before diagnosing high-grade carcinoma, NOS. Of these tumors, salivary duct carcinoma has received the most attention because of its strong association with androgen deprivation and anti-HER2 therapies. Other tumor-type-specific treatments include anti-TRK therapy for high-grade transformation of secretory carcinoma, but further therapeutic options are expected to be developed in the future. It should be emphasized that detailed histological evaluation with adequate sampling, in addition to the effective use of molecular ancillary tests, is of the utmost importance for a suitable diagnosis.

Effectiveness and risk of second primary malignancies after radiotherapy in major salivary gland carcinomas: A retrospective study using SEER database

OBJECTIVE

To investigate the effectiveness of radiotherapy and its association with second primary malignancies (SPMs) risk in major salivary gland carcinomas (MSGCs) patients.

METHODS

Cohort 1 included 7274 surgically treated MSGC patients from the Surveillance, Epidemiology, and End Results database, assessing the effectiveness of radiotherapy. Cohort 2 (n = 4213) comprised patients with ≥5-year survival in Cohort 1 to study SPMs.

RESULTS

Radiotherapy decreased overall survival in MSGCs patients, but improved it in high-grade MSGCs. Cumulative SPMs incidences at 25 years were 16.5% in the radiotherapy (RT) group compared to 14.5% in the non-radiotherapy (NRT) group. For second head and neck carcinomas (SHNCs), incidences were 3.4% in RT versus 1.6% in NRT. Radiotherapy increased the relative risks of tumors, particularly SHNCs (RR = 1.78). The 10-year OS rates of SHNCs after radiotherapy were significantly lower.

CONCLUSION

Radiotherapy improves survival in advanced-stage MSGCs but increases the risk of developing SPMs, particularly SHNCs.

Frequency of Androgen Receptor Positivity in Tumors: A Study Evaluating More Than 18,000 Tumors

Androgen receptor (AR) is a transcription factor expressed in various normal tissues and is a therapeutic target for prostate and possibly other cancers. A TMA containing 18,234 samples from 141 different tumor types/subtypes and 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. AR positivity was found in 116 tumor types including 66 tumor types (46.8%) with ≥1 strongly positive tumor. Moderate/strong AR positivity was detected in testicular sex cord-stromal tumors (93.3-100%) and neoplasms of the prostate (79.3-98.7%), breast (25.0-75.5%), other gynecological tumors (0.9-100%), kidney (5.0-44.1%), and urinary bladder (5.4-24.2%). Low AR staining was associated with advanced tumor stage (pTa versus pT2-4; p < 0.0001) in urothelial carcinoma; advanced pT (p < 0.0001), high tumor grade (p < 0.0001), nodal metastasis (p < 0.0001), and reduced survival (p = 0.0024) in invasive breast carcinoma; high pT (p < 0.0001) and grade (p < 0.0001) in clear cell renal cell carcinoma (RCC); and high pT (p = 0.0055) as well as high grade (p < 0.05) in papillary RCC. AR staining was unrelated to histopathological/clinical features in 157 endometrial carcinomas and in 221 ovarian carcinomas. Our data suggest a limited role of AR immunohistochemistry for tumor distinction and a prognostic role in breast and clear cell RCC and highlight tumor entities that might benefit from AR-targeted therapy.

[Salivary Gland Tumors: Limitations of International Guidelines and Status of the planned AWMF-S3-Guideline]

Primary salivary gland carcinomas are not among the common head and neck tumors. They are characterized by manifold different histological types. Clinically, malignant tumors often cannot be distinguished from benign tumors, so that in these cases malignancy is only established by histopathological diagnosis. These are all reasons why there are relatively few clinical trials on the diagnosis, therapy and follow-up of these tumors. This in turn has the consequence that often only recommendations with limited evidence can be made in clinical guidelines. The most important international guidelines are the National Comprehensive Cancer Network (NCCN) guideline of 2023, the American Society of Clinical Oncology (ASCO) guideline of 2021, the European Society for Medical Oncology (ESMO) guideline of 2022 and still the British National Multidisciplinary guideline of 2016. These 4 international guidelines with their strengths and limitations are presented and commented here. Against this background, the development of a first German S3 clinical guideline on salivary gland tumors is important and expected to be completed in 2023. For the first time in the German guideline program on oncology, benign and malignant tumors are presented together in order to comprehensively do justice to the special features of salivary gland tumors.

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.

Major and minor salivary gland cancers: A multicenter retrospective study

BACKGROUND

Most of the studies on salivary gland cancers are limited for various reasons such as being single-center, small number of patients, including only major or minor SGCs, or only including epidemiological data.

METHODS

A total of 37 medical oncology clinics from different regions of Turkey participated in this retrospective-multicenter study. The analyzed data included clinical and demographical features, primary treatment, metastasis localizations, and treatments and includes certain pathologic features.

RESULTS

The study included data from a total of 443 SGCs. 56.7% was in major salivary glands and 43.3% was in minor salivary glands. Distant metastasis in the major SGCs was statistically significantly more common than in the minor SGCs, locoregional recurrence was statistically significantly more common in the minor SGCs than in the major SGCs (p = 0.003).

CONCLUSIONS

Epidemiological information, metastasis and recurrence patterns, treatment modalities, and survival analysis of the patients over 20 years of follow-up are presented.