Adjuvant RT associated with improved disease site control
2011 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 adjuvant RT."
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.
|Follow HemOncToday.com on Twitter.|