RESULTS
Literature Search and Risk of Bias Assessment
There were 283 manuscripts identified, 56 articles read in full, and 40 articles included in the review (Figure). Among the 16 studies not meeting inclusion criteria, 7 did not provide enough data to isolate head and neck cAS cases,1,13-18 6 did not report outcomes related to the current review,19-24 and 3 did not provide enough data to isolate different treatment outcomes.25-27 Among the included studies, 32 reported use of WLE: WLE alone (n=21)2,7,11,28-45; WLE with RT (n=24)2,3,11,28-31,33-36,38-41,43-51; WLE with CT (n=7)2,31,35,39,41,48,52; WLE with RT and CT (n=11)2,29,31,33-35,39,40,48,52,53; WLE with RT and IT (n=3)35,54,55; and WLE with RT, CT, and IT (n=1).53 Nine studies reported MMS: MMS alone (n=5)39,56-59; MMS with RT (n=3)32,50,60,61; and MMS with RT and CT (n=1).51
Risk of bias assessment identified low risk in 3 articles. High risk was identified in 5 case reports,57-61 and 1 study did not describe patient selection.43 Clayton et al56 showed intermediate risk, given the study controlled for 1 factor.
Patient Demographics
A total of 1295 patients were included. The pooled mean age of the patients was 67.5 years (range, 3–88 years), and 64.7% were male. There were 79 cases identified as T1 and 105 as T2. A total of 825 cases were treated using WLE with or without adjuvant therapy, while a total of 9 cases were treated using MMS with and without adjuvant therapies (Table). There were 461 cases treated without surgical excision: RT alone (n=261), CT alone (n=38), IT alone (n=35), RT with CT (n=81), RT with IT (n=34), and RT with CT and IT (n=12)(Table). The median follow-up period across all studies was 23.5 months (range, 1–228 months).
Comparison Between Surgical and Nonsurgical Modalities
Wide Local Excision—Wide local excision (n=825; 63.7%) alone or in combination with other therapies was the most frequently used treatment modality. The mean (SD) OS was longest for WLE with RT, CT, and IT (n=3; 39.3 [24.1]), followed by WLE with RT (n=447; 35.9 [34.3] months), WLE with CT (n=13; 32.4 [30.2] months), WLE alone (n=324; 29.6 [34.1] months), WLE with RT and IT (n=11; 23.5 [4.9] months), and WLE with RT and CT (n=27; 20.7 [13.1] months).
Nonsurgical Modalities—Nonsurgical methods were used less frequently than surgical methods (n=461; 35.6%). The mean (SD) OS time in descending order was as follows: RT with CT and IT (n=12; 34.9 [1.2] months), RT with CT (n=81; 30.4 [37.8] months), IT alone (n=35; 25.7 [no SD reported] months), RT with IT (n=34; 20.5 [8.6] months), CT alone (n=38; 20.1 [15.9] months), and RT alone (n=261; 12.8 [8.3] months).
When comparing mean (SD) OS outcomes between surgical and nonsurgical treatment modalities, only the addition of WLE to RT significantly increased OS when compared with RT alone (WLE, 35.9 [34.3] months; RT alone, 12.8 [8.3] months; P=.001). When WLE was added to CT or both RT and CT, there was no significant difference with OS when compared with CT alone (WLE with CT, 32.4 [30.2] months; CT alone, 20.1 [15.9] months; P=.065); or both RT and CT in combination (WLE with RT and CT, 20.7 [13.1] months; RT and CT, 30.4 [37.8] months; P=.204).
Comparison Between T1 and T2 cAS
T1 Angiosarcoma—There were 79 patients identified as having T1 tumors across 16 studies.2,31,32,34,39-41,46,48-50,53,58-60,62 The mean (SD) OS was longest for WLE with RT, CT, and IT (n=2; 56.0 [6.0] months), followed by WLE with CT (n=4; 54.5 [41.0] months); WLE with RT (n=30; 39.7 [41.2] months); WLE alone (n=22; 37.2 [37.3] months); WLE with both RT and CT (n=7; 25.5 [18.7] months); RT with IT (n=2; 20.0 [11.0] months); RT with CT (n=6; 15.7 [6.8] months); and RT alone (n=1; 13 [no SD]) months)(eTable).