%0 Journal Article
%T Increased risk of recurrence and disease-specific death following delayed postoperative radiation for Merkel cell carcinoma.
%A Alexander NA
%A Schaub SK
%A Goff PH
%A Hippe DS
%A Park SY
%A Lachance K
%A Bierma M
%A Liao JJ
%A Apisarnthanarax S
%A Bhatia S
%A Tseng YD
%A Nghiem PT
%A Parvathaneni U
%J J Am Acad Dermatol
%V 90
%N 2
%D 2024 Feb 30
%M 37778663
%F 15.487
%R 10.1016/j.jaad.2023.07.1047
%X <B>BACKGROUND: </B>Merkel cell carcinoma (MCC) is often treated with surgery and postoperative radiation therapy (PORT). The optimal time to initiate PORT (Time-to-PORT [ttPORT]) is unknown.<BR><B>OBJECTIVE: </B>We assessed if delays in ttPORT were associated with inferior outcomes.<BR><B>METHODS: </B>Competing risk regression was used to evaluate associations between ttPORT and locoregional recurrence (LRR) for patients with stage I/II MCC in a prospective registry and adjust for covariates. Distant metastasis and death were competing risks.<BR><B>RESULTS: </B>The cohort included 124 patients with median ttPORT of 41 days (range: 8-125 days). Median follow-up was 55 months. 17 (14%) patients experienced a LRR, 14 (82%) of which arose outside the radiation field. LRR at 5 years was increased for ttPORT >8 weeks vs ≤ 8 weeks, 28.0% vs 9.2%, P = .006. There was an increase in the cumulative incidence of MCC-specific death with increasing ttPORT (HR = 1.14 per 1-week increase, P = .016).<BR><B>CONCLUSIONS: </B>The relatively low number of LRRs limited the extent of our multivariable analyses.<BR><B>CONCLUSIONS: </B>Delay of PORT was associated with increased LRR, usually beyond the radiation field. This is consistent with the tendency of MCC to spread quickly via lymphatics. Initiation of PORT within 8 weeks was associated with improved locoregional control and MCC-specific survival.