Abstract 4887
Background
Adenoid cystic carcinoma (ACC) is a rare salivary gland tumor, comprising less than 1% of head and neck neoplasms. Adjuvant radiotherapy (aRT) is suggested for late-stage disease (stage III or IV); however, recent evidence suggests that it may be associated with improved survival even for early-stage disease. Moreover, the prognostic significance of tumor location on overall (OS) and ACC-specific (ACC-S) survival is unclear. We sought to address these knowledge gaps via analyses of the Surveillance, Epidemiology and End Results (SEER) database.
Methods
Intraoral minor (m) and major (M) ACCs from the SEER database (1973-2015) were selected for analysis. Information on age, sex, race, site, stage, treatment and survival was retrieved. The associations of tumor site and aRT with OS and ACC-S were estimated using hazard ratios (HR) and corresponding 95% confidence intervals (CI) obtained via Cox regression models adjusted for covariates as appropriate. Analyses were done using Stata 15.1 (StataCorp LP, College Station, TX).
Results
There were 635 minor and 1,064 major (parotid: n = 547, submandibular: n = 470, sublingual: n = 47) ACC cases included in the analyses. Late-stage patients (49% of total) were significantly more likely to have received aRT (76% vs. 66%; P < 0.01) compared to those with early-stage disease. Submandibular was the only tumour site that demonstrated statistically significant survival differences compared to the other sites; i.e., worse OS (HR = 1.4; 95% CI = 1.1-1.8) and ACC-S (HR = 1.7; 95% CI = 1.2-2.3) compared to minor ACCs. This difference was only evident for late-stage tumours: stage IV submandibular cases had worse OS (HR = 2.1; 95% CI = 1.5-2.8) and ACC-S (HR = 2.4; 95% CI = 1.7-3.4) compared to stage IV minor ACCs. Overall, aRT was associated with better OS (HR = 0.7; 95% CI = 0.6-0.9) and ACC-S (HR = 0.8; 95% CI = 0.6-1.1). This beneficial effect was more pronounced and statistically confirmed only in stage IV disease.
Conclusions
These results, based on SEER data, suggest that aRT is associated with favorable survival only in late-stage ACC and that, among these late-stage tumors, submandibular gland ACCs have substantially worse prognosis than other sites, irrespective of aRT.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Academy of Athens PhD Scholarship to Jason Tasoulas; UNC Lineberger Tier 3 Developmental Award funds and the University Cancer Research Fund to A.L. Amelio.
Disclosure
All authors have declared no conflicts of interest.
Resources from the same session
3839 - Fenofibrate impairs pro-tumorigenic potential of cancer stem cell-like cells within drug-resistant prostate cancer cell populations.
Presenter: Tomasz Wróbel
Session: Poster Display session 3
Resources:
Abstract
3842 - Effect of docetaxel-resistance on the reactivity of prostate cancer cells to metformin
Presenter: Jessica Catapano
Session: Poster Display session 3
Resources:
Abstract
5198 - Cell plasticity and taxanes resistance in metastatic prostate cancer: ESRP1 as a predictive biomarker of taxane response
Presenter: Natalia Jimenez
Session: Poster Display session 3
Resources:
Abstract
2981 - Effect of Selumetinib plus AZD8186 treatment on Cabazitaxel sensitivity in docetaxel-acquired resistant metastatic prostate cancer cell lines
Presenter: Vicenc Ruiz de Porras
Session: Poster Display session 3
Resources:
Abstract
2779 - Anti-tumor activity of cediranib, a pan-inhibitor of vascular endothelial growth factor receptors, in pancreatic ductal adenocarcinoma cells
Presenter: Majid Momeny
Session: Poster Display session 3
Resources:
Abstract
1782 - The molecular mechanisms of EpCAM in regulating tumor progression and development of anti-EpCAM antibodies for colon cancer diagnosis and therapy
Presenter: Han-chung Wu
Session: Poster Display session 3
Resources:
Abstract
1322 - Detection of microRNAs as biomarker for anti-EGFR antibody resistance in colon cancer patients
Presenter: Jens Hahne
Session: Poster Display session 3
Resources:
Abstract
1579 - Serum exosomal microRNA-199b-5p as a novel circulating biomarker to predict response of preoperative chemoradiotherapy for locally advanced rectal cancer
Presenter: Dong Won Baek
Session: Poster Display session 3
Resources:
Abstract
1761 - Live biobank of patient-derived organoids from Thai colorectal cancer patients enables clinical outcome prediction
Presenter: Pariyada Tanjak
Session: Poster Display session 3
Resources:
Abstract
3542 - The biological implications of PDCD6 dysregulation in colorectal cancer
Presenter: Romina Briffa
Session: Poster Display session 3
Resources:
Abstract