Surgical Treatment in Very Advanced (T4b) Adenoid Cystic Carcinoma of the Head and Neck

Abstract

Objective To compare treatment outcomes for T4b head and neck adenoid cystic carcinoma (ACC). Study Design Historical cohort study. Setting National Cancer Database (NCDB). Methods Identified all T4b ACC of head and neck origin diagnosed 2004 to 2019 in the NCDB. Demographics, clinical characteristics, treatment details, and survival were analyzed. Treatment outcomes were analyzed using univariable and multivariable Cox regression. Results We identified 606 cases of T4b ACC. Less than half (284, 47.0%) underwent curative‐intent treatment. Among these, most were treated with primary surgery: surgery + radiotherapy (RT) (122, 43.0%) or surgery + chemoradiotherapy (CRT) (42, 14.8%). The positive margin rate was 78.7%, and 90‐day postoperative mortality was zero. Nonsurgical patients were treated with definitive RT (60, 21.1%) or definitive CRT (60, 21.1%). The median follow‐up was 51.5 months. Overall survival was 77.8% at 3 years. Three‐year survival was higher for patients treated with surgery compared to those treated nonsurgically (84% vs 70%; p = .005). Surgical treatment remained associated with higher survival on multivariable analysis (hazard ratio [HR]: 0.47, p = .005). This effect was most pronounced for oral cavity tumors (HR: 0.17, p = .01). Among matched cohorts of surgically treated patients, there was no difference in 3‐year survival between clinical T4a and T4b tumors (83.3% vs 83.0%, p = .99). Conclusion Long‐term survival for T4b ACC of the head and neck could be expected. Primary surgical treatments can be performed safely and are associated with longer survival. A carefully selected subset of patients with very advanced ACC might benefit from the consideration of surgical treatments.

Surgical Resection Improves Overall Survival in cT4b Major Salivary Gland Cancer

“…34,56 Additionally, the predilection of MSGC for pENE, LVI, and PNI makes achieving microscopically negative margins challenging. 34 Of note, patients with PSM had higher 5-year OS than those undergoing definitive RT or CRT but similar 5-year OS as those with negative margins. Univariable analysis of patients undergoing surgical resection + adjuvant therapy did not associate PSM with poorer OS suggesting that patients with cT4b MSGC may benefit from surgical resection even if the likelihood of achieving negative margins is low.…”

“…Generally, cT4b disease is not considered amenable to surgical resection. 34 Retrospective studies, however, suggest that the cT4b classification in head and neck cancer represents a heterogenous group of tumors, some of which may be closer to cT4a in extent and outcome. 34,38,71,72 Our study investigated this hypothesis in MSGC with (1) the rate of cT4b down-classification, and (2) patterns in OS.…”

“…22,[33][34][35][36][37] In fact, surgical resection of these cancers is safe and mortality within 90 days of surgical resection is reported to be <2%. 22,34,36 Taken together, our results suggest that surgical resection of cT4b MSGC has more benefit than previously assumed. Estimates of survival in cT4b MSGC are limited.…”

“…44,45 Survival analyses included cT4a tumors subject to identical inclusion criteria. 22,34,36 Variables Patient data included age at diagnosis, sex, race, primary payer status, facility type, Charlson-Deyo comorbidity score (CDCS), history of prior malignancy, histology, primary site, grade, clinical tumor-nodal-metastasis classification, pathologic tumor-nodal (pTN) classification, pENE, LVI, tumor diameter, surgical margin status, treatment, length of stay (LOS) and 30-day readmission following surgical resection, 90-day mortality, vital status, and survival time. Cases with a CDCS of 0 had no recorded comorbid conditions.…”

“…Survival time was calculated from 6 months of follow-up to either death or 5 years of follow-up. 22,34,36…”