BMC Cancer 2009, 9:205 http://www.biomedcentral.com/1471-2407/9/205 FOivgeurraell 1survival of all patients Overall survival of all patients. ity, 5-year OS, 100%; lower extremity, 86.5%) while retro- peritoneal tumors demonstrated a reduced 5-year OS rate of 61.1%. There was no significant difference in terms of median age (P = 0.25), sex (P = 0.64), and between those with or without contiguous organ resection (P = 0.19). For histologic status, 20 (90.9%) and 2 (9.1%) patient of low grade liposarcoma experienced local recurrence and distant metastasis, compare to 11 (84.6%) for local recur- rence and 2 (15.4%) for distant metastasis among high grade patients. In terms of resection margins, 23 patients out of 27 patients (85.2%) with negative resection margin developed local recurrence, meanwhile all the 8 patients with positive resection margin experienced local recur- rence. We also evaluated DFS only in 82 patients with negative and microscopically positive margins. Among the evalua- ble 71 patients, 27 patients (38.0%) experienced relapse, in which 4 (14.8%) distant metastasis and 23 (85.2%) local recurrences. Thirteen patients had received excision of recurred lesion for curative intent. The median DFS was Table 2: Analysis of Histologic Subtypes in 5-Year Overall Survival (OS) 17.6 months (95% confidence interval [CI], 14.5–20.6 months) for all patients. The DFS was significantly differ- ent according to the histologic subtype (P = 0.049). The median DFS of low and high grade tumors were 42.4 and 26.8 months, respectively. The 1-year DFS rates for low and high grade tumors were 83.3%, and 44.4%, respec- tively. There were not significantly different DFS in terms of resection margin (P = 0.23), primary site (P = 0.25), and tumor burden (P = 0.80). Impact of adjuvant radiotherapy on survival In all patients, the administration of adjuvant radiother- apy did not seem to confer survival benefit (P = 0.39). We further performed subgroup analyses to identify patients who may benefit most from postoperative adjuvant radi- otherapy. In low grade liposarcoma (well differentiated, and myxoid), a subgroup with adjuvant radiotherapy (n = 22) demonstrated significantly prolonged OS when com- pared with those without adjuvant radiotherapy (n = 50) (5-year OS, 100% vs 82.7%, respectively, P = 0.03, Figure 2A). In contrast, there was no survival difference between the adjuvant radiotherapy (+) and (-) group with high grade liposarcoma (5-year OS, 45.3% vs 43.2%, P = 0.97, Figure 2B). Of note, there was a trend toward worse local control rate (22.7% vs 55.6%, P = 0.08) following adju- vant radiotherapy in high grade tumors when compared with low grade liposarcomas. However, there was no sig- nificant difference respect to adjuvant radiotherapy (+) and (-) group among in patients with negative resection margins (n = 50, P = 0.42) and micro/macroscopically positive resection margin (n = 44, P = 0.61). For DFS, in low grade liposarcoma, patients received adju- vant radiotherapy (n = 21) demonstrated significantly prolonged DFS when compared with those without adju- vant radiotherapy (n = 46) (1-year DFS, 92.9% vs 50.0%, respectively, P = 0.04). Similary, there was no survival dif- ference between the adjuvant radiotherapy (+) and (-) group with high grade liposarcoma (P = 0.67). Prognostic model for patients treated by surgical resection with curative intent The clinical factors predicting poor survival at univariate analyses were as follows: histologic variant (high grade, P < 0.001), status of resection margin (microscopically or Histologic Variant Well differentiated Myxoid Dedifferentiated Round Pleomorphic Total 50 22 15 5 2 No. of death 5-Year OS (%) 5 (10%) 4 (18.2%) 6 (40%) 3 (60%) 2 (100%) 93.3 75.7 54.5 40.0 0 P P < 0.001 Page 4 of 8 (page number not for citation purposes)