Epidemiological study of 790 consecutive primary sacral tumors treated in a single center

English Keywords:Primary sacral tumors  Epidemiological analysis

English Abstract:

  【Abstract】 Objectives: To summarize the epidemiology, surgical treatment and clinical outcome of patients with primary sacral tumor. Methods: From July 2000 to December 2013, 790 patients with primary sacral tumor underwent surgeries in the department of musculoskeletal tumor, Peking University People′s Hospital. There were 416 males and 374 females with a mean age of 44.8 years(ranged from 5 to 78 years). Major pathological diagnosis in the series included 193 chrondromas, 141 giant cell tumors, 83 neurofibromas, 48 schwannomas, 19 malignant schwannomas, 39 myelomas, 16 lymphomas, 26 osteosarcomas, 49 chondrosarcomas, 28 Ewing′s sarcomas/PNETs, 37 teratomas and 127 other tumors. The follow-up period ranged 3-5 years. Pathological diagnosis, dermography, lesion location, surgical treatment, survival and recurrence of tumors were analyzed retrospectively. Results: ①A total of 193 sacral chordoma was enrolled, representing 24.4% of all 790 cases. There were 120 males and 73 females with an average age of 56.7 years(21-75 years), 89 cases with tumors lower than S3 underwent wide or marginal resection, 70 cases with tumors lower than S2 received en bloc resection(21 cases needed re-excision for removing residual lesions on the upper margin of the tumors). In 34 cases with tumors invading the whole sacrum, 19 cases received total en bloc sacrectomy, while piecemeal resection was performed on the remaining cases. 19 cases(9.8%) had metastasis, including lung metastases in 10 patients, bone metastasis in 6 cases and liver metastasis in 3 cases. In 151 cases undergoing their first operations in our department, 57 cases(37.7%) experienced local recurrence. Postoperative progressive free survival rate was 45.1%, 5-year overall survival rate was 87.7%. ②There were 141 sacral giant cell tumor patients, representing 17.8% of all primary sacral tumors. There were 69 males and 72 females with an average age of 34.2 years(16-61 years), 132 cases underwent intraleisional curettage, 3 cases underwent total en bloc sacrectomy. In 6 cases with huge metastases and unavailable for surgery received multiple embolization. 25 cases(18.9%) were noted local recurrence, which included 12 cases without abdominal aorta occlusion. ③There were 150 neurogenic tumors, with 131 benign neurogenic tumors(83 neurofibromas and 48 schwannomas) and 19 malignant schwannomas, which accounted for 19% of all primary sacral tumors. Among 131 benign neurogenic tumors, there were 62 males and 69 females with an average age of 42.3 years(17-67 years). All cases experienced marginal excision and postoperative recurrence occurred in 17(12.9%). ④A total of 26 sacral osteosarcoma was enrolled, which accounted for 3.3% of the whole series. There were 15 males and 11 females with an average age of 25.8years(12-58 years), among them, 16 cases accepted neo-adjuvant chemotherapy, while 21 cases underwent postoperative chemotherapy. 13 cases underwent en bloc resection or total sacrectomy while the other 13 cases underwent piecemeal resection. 12 cases（46%） experienced postoperative recurrence. Three-year survival rate was 43.5% and 5-year overall survival rate was 21.8%. ⑤28 Ewing′s sarcomas/PNETs accounted for 3.5% of all primary sacral tumors. There were 13 males and 15 females with an average age of 22.3 years(5-50 years). 21 cases accepted neo-adjuvant chemotherapy while 27 cases received postoperative chemotherapy and radiotherapy. 14 cases underwent en bloc resection or total sacrectomy while 14 cases underwent piecemeal resection. 15 cases(53.6%) were noted postoperative recurrence. Three-year overall survival rate was 39.1% and 5-year overall survival rate was 19.6%. ⑥A total of 49 sacral chondrosarcomas accounted for 6.2% of all cases. There were 26 males and 23 females with an average age of 42.5 years(17-69 years). Among these 49 paients, 29 cases underwent en bloc resection or total sacrectomy while piecemeal resection was performed on the others. 22 cases(44.9%) were noted postoperative recurrence. The overall survival rate at 2 years and 5 years was 58.7% and 47.0%, respectively. The disease free survival rate at 2 years and 5 years was 42.3% and 31.8%, respectively. Conclusions: Chordoma, giant cell tumor, neurogenic tumor, osteosarcoma, Ewing′s sarcoma, chondrosarcoma and myeloma are the most common primary sacral tumors. These tumors vary in age, sex ratio, location and growth pattern. The resection margin is determined by pathological diagnosis. The local recurrence rate of sacral chordoma after en bloc resection is much lower than that of those undergoing intralesional surgery. The challenges in sacral giant cell tumor surgery are massive intraoperative bleeding and high local recurrence rate. Consequently, a vital measurement to lowering recurrence rate is to control intraoperative bleeding. High grade malignant tumors, such as osteosarcoma and Ewing′s sarcoma, are of very high tendency to recur locally after marginal or intralesional resection. Thus, en bloc resection with wide margin is necessary for these tumors.