Michael Fu, Presenter: Nothing to Disclose

Evan Charles Osmundson MD, PhD, Abstract Co-Author: Nothing to Disclose

Daniel S. Kapp MD, PhD, Abstract Co-Author: Nothing to Disclose

Susan J. Knox MD, PhD, Abstract Co-Author: Nothing to Disclose

Rie von Eyben, Abstract Co-Author: Nothing to Disclose

Purpose:We explored patient, tumor, and treatment factors with regard to recurrence and overall survival in patients with primary MCC treated at a single institution over a 31-year period.Methods:A retrospective review was conducted of 47 patients diagnosed with primary MCC between 1981 and 2012. Outcomes of interest were: first recurrence (local, regional, in-transit, or distant reappearance of tumor), first locoregional recurrence (within the original tumor site or regional lymph nodes), and death. Univariate analysis (Pearson χ2 test) and multivariate logistic regressions were performed to identify factors associated with each outcome.Results:Our cohort had a mean age at diagnosis of 73.3 years and was predominantly Caucasian (74.5%) and male (66.0%). AJCC stage at diagnosis was I in 40.4%, II in 8.51%, III in 25.5%, IV in 4.26%, and unknown in 10.0%. Treatments included primary tumor resection without local radiation therapy (RT) (21.3%), primary tumor resection followed by RT (63.8%), primary site treated with RT only (8.51%), no primary tumor resection or RT (6.4%), sentinel lymph node biopsy (SLNB) (38.3%), lymph node dissection (LND) (27.7%), SLNB followed by RT (27.7%), and LND followed by RT (23.4%). Mean values for RT parameters were: tumor dose 51.6 Gy (in 27.8 fractions) and regional node dose 46.2 Gy (in 24.7 fractions). In total, 53.2% of patients recurred, with 48% failing locoregionally; 61.7% were deceased at last follow-up. Mean follow-up time was 26.0 months.On univariate analysis, lack of SLNB, low pre-RT red blood cell count, and low pre-RT hematocrit were independently associated with recurrence, while head and neck primary site, AJCC stage, nodal stage, and lack of RT treatment with locoregional recurrence. Furthermore, SLNB was independently associated with overall survival. For patients who received RT, the dose, fraction number, and duration of RT treatment and treatment breaks were not associated with outcomes. Multivariate analysis demonstrated a 4.75 adjusted relative risk (95% CI 1.85-5.43, p < 0.05) for head and neck tumors for locoregional recurrence. Year of diagnosis was not significantly associated with any of the outcomes studied.Conclusions:Our results confirm prior reports on the positive impact of RT on locoregional control but not on overall survival in MCC. SLNB was associated with improved survival. Additionally, tumor characteristics including head and neck location, AJCC stage, and nodal stage appear be prognostic for locoregional recurrence. Improvement in survival will require more effective systemic treatments.

Fu, M, Osmundson, E, Kapp, D, Knox, S, von Eyben, R, Merkel Cell Carcinoma (MCC): Demographic, Clinical, and Treatment Parameters of Prognostic Significance.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14044283.html