ASTRO Annual Meeting
MIAMI - Adjuvant radiotherapy improved loco-regional failure control
rates in patients with Merkel cell carcinoma, according to 20-year data from
researchers at the Fox Chase Cancer Center.
From 1990 to 2010, 88 patients with Merkel cell carcinoma presented to
the institution; the researchers retrospectively reviewed these patients for
logo-regional (LR) failure, DFS and OS. The median age of patients was 72 years
and median follow-up was 20 months.
Primary tumor locations included the head and neck (42%), upper
extremity (25%), lower extremity (22%) and trunk (10%). Disease stage varied:
stage I (35%), stage II (16%), stage III (43%) and stage IV (6%). Eighty-one
percent of patients were available for assessment of adjuvant therapy; 79%
received adjuvant radiotherapy (RT) with a median dose of 50 Gy.
LR failure occurred in 26 patients: 14 who received RT vs. 12 who did
not receive RT. PFS rates were superior among patients who received RT vs.
those who did not: 2-year PFS = 70%, 3-year PFS = 63% vs. 2-year PFS = 35%,
3-year PFS = 34% (P=.01). Disease stage among the 14 patients with LR
failure who received RT is as follows: three patients with stage I, one patient
with stage II, 10 patients with stage III. Disease stage among the 12 LR
failures who did not receive RT is: two with stage I, three with stage II, six
with stage III.
According to univariate analysis, the use of adjuvant RT improved the
risk for LR failure (OR=0.256; 95% CI, 0.0073-0.904) and the age- and
stage-adjusted risk for LR (OR=0.227; 95% CI, 0.053-0.967). In addition, RT was
an independent predictor for improved LR control, according to the researchers
(HR=0.057; 95% CI, 0.008-0.407).
For all patients, 2-year OS was 84% and 3-year OS was 72%; 2-year DFS
was 76% and 3-year DFS was 60%.
"RT was an independent predictor of improved LR control after adjusting
for disease stage, which suggests a LR control benefit regardless of patient
stage at presentation," the researchers wrote. "Collaborative multi-institution
efforts would further help identify patients who would best benefit from
For more information:
- Murphy C. Abstract #2995. Presented at: 2011 ASTRO Annual Meeting; Oct. 2-6, 2011; Miami.
Disclosure: The researchers report no relevant financial disclosures.