Zagars G K, Goswitz M S, Pollack A
Department of Radiotherapy, University of Texas M.D. Anderson Cancer Center, Houston, USA.
Int J Radiat Oncol Biol Phys. 1996 Sep 1;36(2):311-9. doi: 10.1016/s0360-3016(96)00265-9.
Liposarcoma is among the more common types of soft-tissue sarcoma. This retrospective review was performed to determine the outcome and delineate prognostic factors for this disease when treated by conservation surgery and radiation.
Between 1964 and 1992, 112 consecutive patients with liposarcoma were treated with conservation surgery and radiotherapy. Univariate and multivariate statistics were used to evaluate the outcome with local control, metastatic relapse, and survival as end points, and to delineate independently significant prognostic factors.
Preoperative radiation to a mean dose of 50 Gy was used in 36 patients and postoperative radiation to a mean dose of 61 Gy was used in 76 patients. At a median follow-up of 9 years (range 2-25), 34 patients (30%) developed disease progression at some site. Local recurrence developed in 14 patients (13%), and the actuarial local relapse rate was 13% at 10 years. Metastases developed in 23 patients (21%) with an actuarial metastatic rate of 23% at 10 years. Five-, 10-, and 15-year survival rates were 79%, 69%, and 61%, respectively. The most important factor influencing outcome--whether local control, metastases, or survival--was tumor histologic subtype. Well-differentiated (15 patients) and myxoid (including round cell) (71 patients) subtypes had a local control rate exceeding 90% at 10 years. No patient with well-differentiated liposarcoma developed metastases. The actuarial metastatic rate for myxoid tumors was 22% at 10 years and was higher for large than small tumors. The pattern of metastases for this variant was atypical with a preponderance of extrapulmonary sites. Pleomorphic liposarcoma (26 patients) was a highly malignant tumor with a high local recurrence rate of 37% and a metastatic rate of 41% at 10 years. Larger pleomorphic tumors had a significantly higher metastatic rate than smaller ones. These biologic factors were reflected in progressively decreasing 10-year survival rates from 87% for well-differentiated lesions, through 76% for myxoid tumors, to 39% for pleomorphic tumors. Although other factors such as positive resection margins and prior local recurrence were also independently significant determinants of outcome, histology was the overriding factor.
Liposarcoma is a highly pleomorphic disease whose outcome is greatly determined by its histologic subtype: so greatly that results reported without histologic stratification are likely meaningless. Conservation surgery and radiation achieve excellent local results and with relatively little metastatic risk for patients with well-differentiated and myxoid liposarcomas. The same treatment strategy appears appropriate for pleomorphic liposarcoma, but with a much smaller expectation of a satisfactory outcome. The development of effective systemic therapy is an important goal for this variant of liposarcoma.
脂肪肉瘤是较为常见的软组织肉瘤类型之一。本回顾性研究旨在确定采用保肢手术和放疗治疗该疾病的疗效，并明确预后因素。
1964年至1992年间，连续112例脂肪肉瘤患者接受了保肢手术和放疗。采用单因素和多因素统计学方法，以局部控制、远处转移复发和生存为终点评估疗效，并明确独立的显著预后因素。
36例患者术前接受了平均剂量为50 Gy的放疗，76例患者术后接受了平均剂量为61 Gy的放疗。中位随访9年（范围2 - 25年），34例患者（30%）在某些部位出现疾病进展。14例患者（13%）发生局部复发，10年精算局部复发率为13%。23例患者（21%）发生转移，10年精算转移率为23%。5年、10年和15年生存率分别为79%、69%和61%。影响预后的最重要因素——无论是局部控制、转移还是生存——是肿瘤组织学亚型。高分化型（15例）和黏液型（包括圆形细胞型）（71例）亚型10年局部控制率超过90%。高分化脂肪肉瘤患者均未发生转移。黏液型肿瘤10年精算转移率为22%，大肿瘤的转移率高于小肿瘤。该亚型的转移模式不典型，肺外部位转移占优势。多形性脂肪肉瘤（26例）是一种高度恶性肿瘤，10年局部复发率高达37%，转移率为41%。较大的多形性肿瘤转移率明显高于较小的肿瘤。这些生物学因素反映在10年生存率逐渐下降，从高分化病变的87%，到黏液型肿瘤的76%，再到多形性肿瘤的39%。尽管其他因素如手术切缘阳性和既往局部复发也是独立的显著预后决定因素，但组织学是首要因素。
脂肪肉瘤是一种高度多形性疾病，其预后很大程度上取决于组织学亚型：以至于未按组织学分层报告的结果可能毫无意义。保肢手术和放疗对高分化和黏液型脂肪肉瘤患者可取得良好的局部效果，且转移风险相对较小。相同的治疗策略似乎也适用于多形性脂肪肉瘤，但预期获得满意结果的可能性要小得多。开发有效的全身治疗方法是这种脂肪肉瘤亚型的一个重要目标。
