Implementation of submandibular gland transfer: A multi-institutional study of feasibility and time to treatment.

Presentation: C069
Topic: Pharynx / Larynx Cancer
Type: Poster
Date: Thursday, April 19, 2018
Session: 9:00 AM - 7:00 PM
Authors: John Pang, MD1, Harry H Ching, MD2, Ryan H Sobel, MD3, Ryan K Orosco1, Joseph A Califano III, MD1, Robert C Wang, MD2, Charles S Coffey, MD1
Institution(s): 1University of California - San Diego, Head and Neck Surgery, 2University of Nevada Las Vegas School of Medicine, 3Johns Hopkins Head & Neck Surgery at Greater Baltimore Medical Center

Background: Submandibular gland transfer (SMGT) is a novel technique to preserve the salivary function of patients receiving radiation for head and neck cancer. Despite more than a decade of evidence demonstrating effectiveness in increasing salivary flow and preventing xerostomia, SMGT has yet to be widely adopted. We evaluate the feasibility of incorporating SMGT into clinical practice at multiple academic institutions, including assessment of potential treatment delay related to SMGT and identification of clinical factors predictive of treatment delay.

Methods: Forty-nine patients were identified between June 23, 2004 and July 17, 2017 who underwent SMGT for prevention of xerostomia in the setting of definitive surgery (n = 19) or definitive nonsurgical therapy (n=30). Retrospective chart review extracted clinical characteristics and relevant time points (dates of pathologic diagnosis, primary oncologic surgery, SMGT, chemotherapy initiation, radiation simulation). Treatment delay was defined as > 60 days from diagnosis to definitive non-surgical therapy, or > 6 weeks from primary surgery to adjuvant treatment, based upon contemporary guidelines. Statistical tests included Fisher’s exact test as well as Kruskal Wallis and Wilcoxon rank-sum non-parametric test of quantitative data.

Results: The majority of patients were male (86%) and white (78%) with a mean age of 60 yrs. (SD 10.1 yrs.). Most patients presented with AJCC v7 stage IV (73%) oropharynx tumors (88%) of squamous cell histology (94%). P16 was positive in 85%. Non-surgical therapy was primary treatment for 30 patients (61%). Surgery was primary treatment for 19 patients (39%). Median time from pathologic diagnosis to primary treatment was 35 days (IQR 28 – 45). Median time from pathologic diagnosis to SMGT was 28 days (IQR 21 – 44). Treatment delay was observed in 8/49 patients (16%; 3/49 > 60 days to primary treatment; 5/49 > 6 weeks from surgery to adjuvant therapy). Treatment delay was significantly associated with problems with insurance approval [one initial consultation delay and one radiation oncology approval delay, 2/2 (100%) vs. 6/47 (13%); p = 0.024] and surgery as primary treatment [6/19 (32%) vs. 2/30 (7%); p = 0.043].

Conclusion: SMGT can be implemented without treatment delay for the majority of patients. Pre-treatment risk factors for treatment delay include difficulty with insurance approval and surgery as primary treatment. In such cases, SMGT may be difficult to implement while adhering to recommended treatment guidelines.