Outcome of Adenoid Cystic Carcinoma of Head and Neck After Postoperative Intensity Modulation Radiotherapy: A Single Institution Study

Concurrent chemoradiotherapy versus radiotherapy alone in postoperative high-risk adenoid cystic carcinoma of the head and neck: A propensity score matched analysis

Background

The role of concurrent chemoradiotherapy (CCRT) in postoperative head and neck adenoid cystic carcinoma (ACC) remains controversial due to the limited evidence from randomized trials. This study assessed the effectiveness of CCRT by comparing a prospective CCRT group with a retrospective radiation（RT） alone group using propensity score matching (PSM).

Methods and materials

Postoperative head and neck ACC patients with T3-4/N1-3 M0 disease or after R1/R2 resection were enrolled. All patients underwent intensity-modulated radiation therapy (IMRT), and CCRT group received two cycles of concurrent docetaxel and nedaplatin. To ensure comparability, PSM were utilized. Following PSM, survival outcomes were analyzed using Kaplan-Meier curves and compared using the log-rank test.

Results

A prospective CCRT group of 55 patients and a retrospective RT alone group of 160 patients were included. The multivariate Cox regression analysis showed no association between CCRT and overall survival (OS) (hazard ratio [HR] = 0.71, 95 %CI: 0.24-2.08, p = 0.537), or other survival outcomes. To mitigate potential confounding factors, a 1: 1 PSM analysis was performed. With a median follow-up of 51 months, post-PSM analysis (including 48 patients in each group) indicated no significant differences in OS (estimated 5-year OS rates: 90.7 % versus 84.3 %, p = 0.331), locoregional recurrence-free survival (LRRFS) (p = 0.261), distant metastasis-free survival (DMFS) (p = 0.425), or disease-free survival (DFS) (p = 0.600) between two groups. The multivariate Cox regression analysis also showed no association between CCRT and OS (HR = 0.29, 95 %CI: 0.06-1.38, p = 0.119), or other survival outcomes.

Conclusion

The addition of concurrent chemotherapy to postoperative IMRT did not confer a survival benefit in terms of LRRFS, DMFS, DFS, or OS in patients with head and neck ACC. Upcoming results from randomized studies are anticipated to shed more light on this debated issue. CCRT should be avoided outside of clinical trials.

Survival Outcomes in Adenoid Cystic Carcinoma of the Head and Neck: A Systematic Review of 17 497 Cases and Meta-Analysis

BACKGROUND

Adenoid cystic carcinoma (ACC) is a slow-growing tumor with variable outcomes, making follow-up protocols challenging. This review analyzed outcomes in ACC, focusing on patterns and factors related to adverse prognoses.

METHODS

A search was conducted on March 25, 2024, in MEDLINE, PubMed, Scopus, and EMBASE. Studies analyzing ACC survival were included, while those lacking these data or focusing on a single ACC site were excluded. The Joanna Briggs Institute's Critical Appraisal tool was used to assess the risk of bias, and the metanalysis was performed using R software.

RESULTS

Among 57 studies (17 497 patients), ACC predominantly affected women (mean age: 52.69 years) and occurred mainly in minor salivary glands. Distant metastasis was the most frequent adverse outcome, occurring at 34.8 months on average. Locoregional metastasis and local recurrence occurred at 27.5 and 31.3 months, respectively. Five-, 10-, 15-, and 20-year survival rates were 73.8%, 48.5%, 42.3%, and 26.5%, respectively. Poor survival predictors included advanced T stage, positive lymph nodes, solid tumors, distant metastasis, and positive surgical margins.

CONCLUSIONS

Distant metastasis is the most frequent adverse outcome in ACC, and prognostic factors are related to advanced and residual tumors.

Prognostic factors of palatal adenoid cystic carcinoma: A single-center analysis of 85 cases

Objective

The purpose of this retrospective study was to describe the clinicopathological characteristics of primary adenoid cystic carcinoma (ACC) of the palate and to identify the factors affecting prognosis.

Methods

The medical records of 85 patients with primary ACC of the palate treated with surgery, with or without adjuvant radiotherapy/chemotherapy, from 2009 to 2019 were reviewed. The relationship of different clinical parameters with locoregional recurrence (LR), distant metastasis (DM), and overall survival (OS) were analyzed.

Results

Median follow-up time was 44.6 months. LR and DM rates were 24.7% and 25.9%, respectively, and the 5-year OS and disease-free survival (DFS) rates were 85.9% and 55.1%, respectively. Multivariate analysis showed that positive margins were independently associated with the risk of LR (p < .001). Positive margins (p = .001) and high histological grade (p = .031) were significantly associated with shorter OS.

Conclusion

Positive surgical margins are a strong adverse prognostic factor affecting LR and OS in patients with ACC; apart from that, high histopathological grade is an independent predictor of poor OS.

Level of Evidence

Level 3 (Prognosis - Cohort study).

Assessing the Impact of Charged Particle Radiation Therapy for Head and Neck Adenoid Cystic Carcinoma: A Systematic Review and Meta-Analysis

Purpose: Head and neck adenoid cystic carcinoma (HNACC) is a radioresistant tumor. Particle therapy, primarily proton beam therapy and carbon-ion radiation, is a potential radiotherapy treatment for radioresistant malignancies. This study aims to conduct a meta-analysis to evaluate the impact of charged particle radiation therapy on HNACC. Methods: A comprehensive search was conducted in Pubmed, Cochrane Library, Web of Science, Embase, and Medline until December 31, 2022. The primary endpoints were overall survival (OS), local control (LC), and progression-free survival (PFS), while secondary outcomes included treatment-related toxicity. Version 17.0 of STATA was used for all analyses. Results: A total of 14 studies, involving 1297 patients, were included in the analysis. The pooled 5-year OS and PFS rates for primary HNACC were 78% (95% confidence interval [CI] = 66-91%) and 62% (95% CI = 47-77%), respectively. For all patients included, the pooled 2-year and 5-year OS, LC, and PFS rates were as follows: 86.1% (95% CI = 95-100%) and 77% (95% CI = 73-82%), 92% (95% CI = 84-100%) and 73% (95% CI = 61-85%), and 76% (95% CI = 68-84%) and 55% (95% CI = 48-62%), respectively. The rates of grade 3 and above acute toxicity were 22% (95% CI = 13-32%), while late toxicity rates were 8% (95% CI = 3-13%). Conclusions: Particle therapy has the potential to improve treatment outcomes and raise the quality of life for HNACC patients. However, further research and optimization are needed due to the limited availability and cost considerations associated with this treatment modality.

Adenoid cystic carcinoma of the head and neck: Patterns of recurrence and implications for intensity-modulated radiotherapy

BACKGROUND

We seek to inform radiotherapy (RT) delivery for adenoid cystic carcinoma of the head and neck (ACC) by evaluating RT techniques and recurrence patterns.

METHODS

We identified patients with ACC treated with curative-intent RT from 2005 to 2021. Imaging was reviewed to determine local recurrence (LR).

RESULTS

Ninety-one patients were included. The 5-year LR risk was 12.2% (6.6-22.7). One patient each experienced a marginal and out-of-field recurrence. Patients receiving >60 Gy postoperatively had a 5-year LR risk of 0% compared to 10.7% (4.2-27.2) with ≤60 Gy. Those receiving 70 and <70 Gy definitively had a 5-year LR risk of 15.2% (2.5-91.6) and 33.3% (6.7-100.0), respectively. No patients had regional nodal failure.

CONCLUSIONS

Modern, conformal RT for ACC results in low rates of LR. Doses >60 and 70 Gy may improve control in the postoperative and definitive settings, respectively. Elective nodal treatment can be omitted in well-selected patients.

EGF/EGFR Promotes Salivary Adenoid Cystic Carcinoma Cell Malignant Neural Invasion via Activation of PI3K/AKT and MEK/ERK Signaling

BACKGROUND

Salivary adenoid cystic carcinoma (SACC) is one of the most common malignant cancers of the salivary gland, and 32.4-72.0% of SACC cases exhibit neural invasion (NI), however, the molecular mechanism underlying the high invasion potential of SACC remains unclear.

METHODS

The present study investigated the role of epidermal growth factor receptor (EGFR) in the AKT inhibition- or mitogen-activated protein kinase kinase (MEK)-induced NI and epithelial-mesenchymal transition (EMT) in SACC cells using EGFR, PI3K and MEK inhibitors. SACC 83 cell viability was assessed using an MTT assay, and a wound healing assay was performed to evaluate cell migration. Immunohistochemical staining with streptavidin peroxidase was used to detect the positive expression rate of EMT, AKT, phosphorylated (p)-AKT, ERK and p-ERK proteins. The impact of EGFR, PI3K and MEK inhibitors on tumor growth and NI was examined in a xenograft model in nude mice.

RESULTS

EGF and EGFR are effective in increasing cell viability, migration and invasion. SACC metastasis is affected by the PI3K/AKT and MEK/ERK pathways, both of which are initiated by EGF/EGFR. The EMT and NI are regulated by the EGF/EGFR, PI3K/AKT and MEK/ERK pathways. The present findings demonstrate the importance of suppressed EGFR/AKT/MEK signaling in NI in SACC by neural-tumor co-culture in vitro. Furthermore, our preclinical experiment provides solid evidence that injection of EGFR, PI3K and MEK inhibitors obviously suppressed the tumor growth and NI of SACC cells in nude mice.

CONCLUSION

It was identified that inhibitors of EGFR, PI3K/AKT or MEK/ERK suppressed the proliferation, migration and NI of SACC-83 cells via downregulation of the PI3K/AKT or MEK/ERK pathways. It was also demonstrated that inhibition of EGFR abolishes EMT in SACC by inhibiting the signaling of PI3K/AKT and MEK/ERK. The present results suggest the potential effectiveness of targeting multiple oncogenes associated with downstream pathways of EGF/EGFR, as well as potential therapeutic targets to limit NI in SACC by PI3K/AKT or MEK/ERK inhibition.

Patterns of Tumor Infiltrating Lymphocytes in Adenoid Cystic Carcinoma of the Head and Neck

Simple Summary

Adenoid cystic carcinoma (ACC) is a rare tumor with late occurring metastases and recurrences, which makes it necessary for patients to be monitored closely even beyond the usual five years. So far, there is hardly any effective treatment in the palliative situation and trials on immunotherapeutic drugs have not been successful. We sought to find possible prognostic markers by analyzing patterns of tumor infiltrating immune cells and additionally to learn more about possible reasons for this lack of response to immunotherapy. It appears from our data that it is not relevant for prognosis if the tumor is infiltrated by immune cells. This might also be the reason that immunotherapies do not work in this particular disease, which suggests that ACC is not recognized by infiltrating immune cells. Therefore, the tumor would have to be made visible to the immune system, for example, through vaccinations.

Abstract

Adenoid cystic carcinoma (ACC) is a rare malignancy in the head and neck. The prognosis remains poor and late recurrences often occur after 5 years and later. To date, there are no reliable prognostic markers for ACC. In several solid tumors, tertiary lymphoid structures (TLS) are associated with improved survival. This study aims to investigate the role of distribution patterns of tumor infiltrating immune cells (TIL) in ACC. A cohort of 50 patients from three different cancer centers was available for analysis. Sections were stained for CD3, CD4, CD8 and CD20 and evaluated with regard to their distribution of TIL. Patterns were determined as infiltrated-excluded, infiltrated-inflamed and presence of tertiary lymphoid structures. About half of the cases showed an infiltrated-excluded TIL pattern and only a minority of six cases had TLS present within the tumor. Within the inflamed phenotype CD3+ cells were by far the most abundant lymphocyte subtype, and within this compartment, CD8+ T cells were predominant. There was no influence on overall or disease-free survival by any of the TIL patterns. This indicates that ACC is a tumor with very low immunogenicity and even abundance of lymphocytes does not seem to improve prognosis for this disease. Therefore, the observed lack of response towards immunotherapy is not surprising and other methods to induce recognition of ACC by the immune system must be found.