Outcomes of cutaneous squamous cell carcinoma of the head and neck with parotid metastases.
BACKGROUND
Cutaneous squamous cell carcinoma of the head and neck (cHNSCC) metastatic to the parotid has a moderate risk of recurrence despite multimodality treatment. Immunosuppression is associated with lower rates of long-term cure. Our aim was to review outcomes of current management in a tertiary centre with a view to targeting future strategies.


METHODS
A retrospective review of clinico-pathological data and outcomes for patients with metastatic cHNSCC involving the parotid gland, undergoing radical surgery and adjuvant radiotherapy during 2000-2014 was conducted. The Kaplan-Meier method was used to determine time-to-event outcomes.


RESULTS
One hundred and thirty-two patients met the inclusion criteria. Median follow-up was 5.0 years. Five-year overall (OS), cancer-specific (CSS) and progression free survival (PFS) were 44% (95% Confidence Interval (CI) 34-53%), 64% (95% CI 52-74%) and 37% (95% CI 28-47%) respectively. Locoregional control (LRC) was 68% (95% CI 55-77%) at 5 years. Immunosuppressed patients fared worse (compared with immune-competent) with five-year OS, CSS, and PFS of 14% versus 53% (HR = 3.19; 95% CI 1.91-5.34), 40% versus 71% (Hazard Ratio (HR) = 2.92; 95% CI 1.38-6.19) and 10% versus 46% (HR = 2.51; 95% CI 1.52-4.14) respectively. On multivariate analysis, immune status strongly predicted OS (P < 0.001), CSS (P = 0.003), DMFS (P < 0.001) and PFS (P < 0.001), but not LRC. Largest lymph node size was the only significant factor predictive for LRC on multivariate analysis (P = 0.02).


CONCLUSIONS
Despite multimodality treatment metastatic cHNSCC involving the parotid shows moderate rates of recurrence. Immunosuppressed patients with this disease have a particularly poor prognosis, demonstrating lower rates of CSS with similar rates of LRC compared to their immunocompetent counterparts.
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia. lmcdowell@lrh.com.au.
Lachlan J
LJ
McDowell
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
Tze-Jian
TJ
Tan
Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
Mathias
M
Bressel
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.|University of Melbourne, Melbourne, Victoria, Australia.
Vanessa
V
Estall
Division of Surgical Oncology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
Stephen
S
Kleid
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.|University of Melbourne, Melbourne, Victoria, Australia.
June
J
Corry
Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia.
Meredith L
ML
Johnston
D002294:Carcinoma, Squamous Cell / Q000150:complications* / Q000401:mortality / Q000473:pathology*; D006258:Head and Neck Neoplasms / Q000150:complications* / Q000401:mortality / Q000473:pathology*; D006801:Humans; D016867:Immunocompromised Host; D053208:Kaplan-Meier Estimate; D008198:Lymph Nodes / Q000033:anatomy & histology; D009364:Neoplasm Recurrence, Local; D010307:Parotid Neoplasms / Q000401:mortality / Q000473:pathology / Q000556:secondary*; D012189:Retrospective Studies; D000077195:Squamous Cell Carcinoma of Head and Neck
immunosuppression; parotid neoplasms; radiotherapy; skin neoplasms; squamous cell