Post-treatment Tumor Surveillance: Towards Determining an Optimal Follow up and Imaging Protocol
Despite aggressive therapy with surgery, radiation, and chemotherapy, oral, head and neck squamous cell carcinoma (SCCA) still has a high incidence of locoregional and distant failure1. For this reason, structured follow up is a critical component of the care of cancer survivors. The NCCN has published guidelines for the frequency of follow up and the timing for the first post-treatment imaging study2. Unfortunately, these recommendations are based on convention, as there is a dearth of evidence to draw from. Although it is widely known that most failures occur within two years post treatment3, there is little data determining the optimal method for identifying them. Furthermore, the NCCN does not make recommendations for surveillance imaging beyond the first 6 months. In this study, we aim to establish the natural history for treatment failure in oral, head and neck SCCA and how they are identified.
MATERIALS AND METHODS:
This is a retrospective review of patients treated at two cancer centers. All patients treated for oral, head and neck SCCA from July 2012 to March 2014 at these two centers were included in this study. Patients were excluded if they had incomplete records or were lost to follow up. All patients were treated according to NCCN guidelines. Patients had scheduled follow up every 3 months for two years, every 6 months for the third year, and annually for fourth and fifth year. Out of sequence follow up visits were patient directed based on symptoms. The first post treatment imaging was obtained 3 months following completion of treatment. Either a PET/CT or CT with contrast were used for imaging.
RESULTS:
170 patients met inclusion criteria. Of these, 41 patients had treatment failures (3 with incomplete response or failure during treatment, 30 with locoregional recurrences, 4 with second primaries, and 14 distant recurrences). 28 (68%) of these occurred in the first two years following treatment. 8 patients are deceased (all related to recurrent cancer). Of the locoregional failures, 17 (47%) were identified due to evaluation of patient symptoms, 11(31%) were identified on routine surveillance exam, and 8(22%) were identified on routine surveillance imaging. For distant recurrences, the results were 5 (36%), 1(7%), and 8(57%) respectively. Interestingly, of HPV+ oropharynx SCCA, the majority (60%) failed due to distant recurrence and were identified by surveillance PET/CT (66%). In contrast, oral SCCA more often failed locoregionally (80%) and their identification was more symptom or surveillance exam directed (70%).
CONCLUSIONS:
Patients with oral SCCA are more likely to have locoregional failure and have recurrences diagnosed on structured surveillance exam or based on symptom directed examination and imaging. HPV+ oropharynx SCCA is more likely to fail distantly, with asymptomatic recurrences identified with imaging. Post treatment surveillance protocols regarding examination and imaging frequency should be tailored based on likelihood of detecting recurrences for different SCCA based on tumor location and other clinical factors.
1. Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D.: Global cancer statistics. CA: A Cancer Journal for Clinicians61:69–90, 2011.
2. Pfister DG, Ang KK, Brizel DM, Burtness BA, Cmelak AJ, Colevas AD, Dunphy F, Eisele DW, Gilbert J, Gillison ML.: Head and neck cancers. Journal of the National Comprehensive Cancer Network9:596–650, 2011.
3. Kissun D, Magennis P, Lowe D, Brown JS, Vaughan ED, Rogers SN.: Timing and presentation of recurrent oral and oropharyngeal squamous cell carcinoma and awareness in the outpatient clinic. Br J Oral Maxillofac Surg44:371–376, 2006.