, they account for less than 5% of all osseous neoplasms , and less than 0.2% of all cancers24,25 ) . dorfman and czerniak9 ) analyzed data on 2627 primary malignant tumors of bone including spine collected in the surveillance , epidemiology , and end results ( seer ) program . their tumors were osteosarcoma ( 35.1% ) , followed by chondrosarcoma ( 25.8% ) , ewing 's sarcoma ( 16.0% ) , chondroma ( 8.4% ) , and malignant fibrous histiocytoma ( mfh ) ( 5.6% ) . these tumors can cause significant morbidity and mortality secondary to local invasion and destruction of adjacent structures including bone , nerves , and vascular structures , and they can metastasize to distant organs19,24 ) . tremendous advancement has been made in the surgical and medical therapy of malignant primary bone tumors19,27,34 ) , but their spinal involvement is still associated with poor prognosis17,22 ) . the understanding of the epidemiology of primary spinal sarcomas has been limited to small case series and controlled trials in the treatment were impossible because of their rarity23 ) . these facts resulted in non - uniform approach in the treatment of the spinal sarcomas16,27 ) . and , a general understanding of the presentation and survival of primary spinal sarcomas is also lacking39 ) . for this reason the establishment of a bone tumor registry provides a valuable source of information and facilitates reasonable treatment of these tumors16,28 ) . it was known that primary sarcomas of the spine had low survival and high recurrence rate compared to sarcoma occurring in extremity2,8,22,24,31,37,41 ) . the radical or wide excision is required in sarcoma treatment , but it is difficult to perform the radical excision due to the risk of neural or vascular injuries7,19 ) . in addition , high dose radiation can not be delivered to residual mass , because it may produce radiation - induced spinal cord injury3,5,16 ) . the purpose of this study is to investigate the survival and recurrence rate of primary spinal sarcoma patients who underwent non - radical surgery plus adjuvant therapy or nonoperative treatments . study cohort was the patients who were treated in our hospital due to primary spinal sarcomas from january 2000 to december 2010 . the total number of patients was 29 , and their medical records and radiologic images were analyzed retrospectively . the average age of patients was 42.9 years old ( range , 11 to 76 years ) . with regard to tumor histology , malignant peripheral nerve sheath tumor ( mpnst , 8 patients ) was the most prevalent , and other tumors included chondrosarcoma ( 6 patients ) , osteosarcoma ( 5 patients ) , mfh ( 4 patients ) , ewing sarcoma and synovial sarcoma ( each 3 patients ) . regarding lesion location , 21 patients had a tumor on mobile spine ( 8 lesion in cervical , 10 in thoracic and , 3 in lumbar spine ) , while 8 patients had a tumor on rigid spine ( sacrum ) . with regard to the lesion multiplicity , 17 patients had a single lesion where the tumor was confined to one segment at diagnosis , and 12 patients had multiple level involvement . ten patients showed distant metastasis during follow - up , and 3 patients had metastasis at diagnosis . the time for the development of distant metastasis was , on the average , 24 months . the site of distant metastasis was lung in 9 patients and brain in one patient . twenty - seven patients complained of pain and 14 patients had motor weakness at the time of diagnosis . twenty - six patients could walk at diagnosis , and 15 patients could walk also at the last follow - up . among 14 patients who could not ambulate , 10 patients could not walk due to neurologic deficit and remaining 4 patients could not walk due to intractable pain . the period for which ambulatory function was maintained was average 46 months , 13 patients could walk longer than 46 months , whereas 16 patients shorter than 46 months . in initial treatment , surgery was chosen in 17 patients , irradiation in 6 patients , and chemotherapy in 6 patients . operations were performed 44 times in a total of 23 patients and 12 patients received the surgery two or more times . as for surgical procedure , all the operations were subtotal or partial removal of tumors , not radical excision . there were 4 cases of wound infection , one case of screw malposition , one case of hypoglossal nerve palsy , and one case of pulmonary complication . as for radiation therapy , 27 patients received radiation therapy ( rt ) during the treatment period . conventional rt was given to 10 patients , 8 patients received stereotactic radiosurgery , and 9 patients received both of them . tumor was classified into 3 groups based on the histologic types ( table 2 ) . osteosarcoma and mfh , being known to have similar clinical behavior , belonged to first group ( group i ) . ewing ' sarcoma and chondrosarcoma which were reported to have long survival belonged to the second group ( group ii ) . the remaining mpnst and synovial sarcoma were included into the third group ( group iii ) . in this study , we sought to determine overall survival ( os ) and progression free survival ( pfs ) in primary sarcoma of spine , and to document pain level changes and ambulatory status during follow - up . thirteen prognostic factors affecting survival , systemic recurrence and ambulatory function were analyzed : age ( 42 or 43 ) , gender , tumor histologic type ( osteosarcoma and mfh , or chondrosarcoma and ewing sarcoma , or mpnst and synovial sarcoma ) , lesion location ( mobile spine or rigid spine ) , weakness at diagnosis , pain at diagnosis , ambulation at diagnosis , initial treatment method , radiation therapy , kind of irradiation , surgery , chemotherapy and distant metastasis . chi - square and fisher exact tests were used for categorical variables and student 's t test were used for continuous and ordinal variables , as appropriate . a p value 0.05 ( two - tailed ) the data were compiled and analyzed with the software package spss , version 14.0 ( spss inc . , chicago , il , usa ) . median of os in the study cohort was 60 months [ 95% confidence interval ( ci ) , 33.17 - 86.83 months ] . 1 ) . osteocarcoma and mfh group showed the shortest survival of 30 months ( 95% ci , 5.59 - 54.40 months ) . in group ii ( ewing sarcoma and chondrosarcoma group , which was known to have the longest survival , showed median survival of 74 months ( 95% ci , 16.07 - 131.93 months ) . however , there was no statistical significance among three groups . among total 29 patients , fourteen patients died of the disease progression and two patients the medical condition unrelated to tumor progression such as sepsis or acute renal failure . statistically significant prognostic factors associated with survival were the presence of distant metastasis ( table 3 ) . the patients with distant metastasis , whose median survival was 30 months ( 95% ci , 7.23 - 52.77 months ) showed significantly shorter survival than the cases without metastasis whose median survival was 85 months ( 95% ci , 57.29 - 112.71 months ; p=0.002 ) ( fig . twenty - three out of 29 patients experienced the recurrence during the follow - up . the recurrence implies not only the local recurrence at the tumor site but also the systemic recurrence including the distant metastasis . pfs of patients was 26 months ( 95% ci , 14.09 - 37.91 months ) . there were no statistically significant prognostic factors associated with recurrence ( table 4 ) . among 27 patients who complained of pain at the time of diagnosis , pain was determined to be controlled when post - treatment vas decreased by more than two points or the amount of pain medication was reduced . mean vas fell to 4.562.10 points after the treatment with 3.892.08 point decrease ( p=0.001 ) . pain score of patients who underwent the surgical treatment was measured upon the first follow - up after the surgery . pain score of patients who received non - surgical treatments was measured within a month upon the completion of initial treatment . likewise , pain was reduced after the initial treatment , but the pain increased again with recurrence after 27 months . there were no statistically significant prognostic factors associated with the pain control . as a whole , median period during which ambulatory function was maintained was 54 months ( 95% ci , 43.33 - 104.67 months ) . statistically significant prognostic factor associated with post - treatment ambulatory function was the presence of weakness at initial diagnosis ( table 5 ) . among patients who did not show motor weakness at initial diagnosis , patients who maintained the walking ability at the last follow - up were 86.7% , which is twice as much as patients who had weakness at initial diagnosis ( 42.9% ) ( p=0.013 ) ( fig . treatments for primary spinal sarcomas involve a multi - modality approach consisting of surgery , radiation therapy and chemotherapy12,30 ) . the experience in the treatment of extremity sarcomas have been applied to cases of spinal sarcomas3 ) . although great advances have been achieved in the treatment , oncological outcome in spinal sarcomas is worse than that of soft tissue sarcomas in extremities20,33,40 ) . in extremity sarcomas , many reports on survival and recurrence vasileios et al.37 ) reported that 5-year survival rate of mfh patients was 66% and the recurrence and the metastasis rates were 31% . tural et al.36 ) reported that the recurrence rate was 23% and 5-year survival rate was 72% through retrospective study of adult ewing sarcoma patients . according to stanelle et al.'31)s paper , it was reported that 73% of 5-year survival rate , 65% of 10-year survival rate in synovial sarcoma and 41% of recurrence rate of this disease . arndt et al.2 ) reported 65% of 5-year survival rate in osteosarcoma . in our study , 5-year survival rate was 41% , 61% and 45% in osteosarcoma / mfh group , chondrosarcoma / ewing sarcoma group and mpnst / synovial sarcoma group , respectively . since primary spinal sarcomas are very rare diseases24,25 ) , the standard treatment method has not been established28,34,38,39 ) . however , treatment for osteosarcoma and chondrosarcoma is being conducted in uniform fashion . in cases of osteosarcoma postoperative adjuvant chemotherapy is sometimes done when indicated . in chondrosarcoma , chemotherapy or radiation therapy improvement in surgical approach to the entire vertebral column has made it technically feasible to resect tumors involving the spine at all levels , and the development of new instrumentation systems has enabled surgeons to reconstruct entire vertebral segments after resection27,34 ) . but , the proximity of the dural sac , aorta , vena cava , and esophagus makes it difficult to achieve adequate negative surgical margins19 ) . the en bloc resection of a spinal segment is a relatively recent concept , which is different from a complete piecemeal corpectomy7 ) . it is recognized that , with rare exceptions , the rate of local recurrence depends on the adequacy of the resection , even when adjuvant therapy is used6,20,28,39 ) . soft tissue sarcomas were further dichotomized as either high ( g2 ) or low ( g1 ) grade according to the classification of enneking et al.10 ) low - grade tumors are well differentiated , have few mitoses , and moderate cytologic atypia . high grade lesions are characterized by poor differentiation , a high cell / matrix ratio , and a high mitotic rate , necrosis , and microvascular invasion1,2,34,41 ) . tumor growth and progression are variable depending on the differences in the grade of differentiation . in addition , these histological differences produce the differences in the susceptibility to radiation and the reactivity to chemotherapy , and affect the selection of adjuvant treatment . a number of studies have attempted to identify prognostic factors for survival in primary sarcomas of the spine8,22,23 ) . damron et al.8 ) investigated the survival and epidemiologic data from the national cancer database of the american college of surgeons . they reported that 5-year survival rate was 53.9% for osteosarcoma , 75.2% for chondrosarcoma , and 50.6% for ewing 's sarcoma . mukherjee et al.24 ) analyzed overall survival and prognostic factors affecting survival time in malignant primary osseous spinal tumors . they searched the seer database to identify all registered cases of ewing sarcoma , osteosarcoma and chondrosarcoma to assess histology specific survival during the period from 1973 to 2003 . total study patients were identified as 579 with chondrosarcomas , 430 with osteosarcoma , and 469 with ewing sarcomas . overall median survival was histology - specific ( osteosarcoma , 11 months ; ewing sarcoma , 26 months ; chondrosarcoma , 37 months ) and significantly worse in patients with distant metastasis at presentation for all tumor types . schoenfeld et al.29 ) performed a retrospective review of cases of osteosarcoma involving the spine treated . local recurrence developed in 27% , and metastasis occurred in 62% . in our study , overall survival was 30 months in the osteosarcoma and mfh group and 72 months in the ewing ' sarcoma and chondrosarcoma group , which were quite different from those from mukherjee et al . 's study . however , their study analyzed the data obtained from last 30 years , but our study analyzed the data from recent 10 years . two - fold increase in survival is observed between previous 30 years and recent 10 years . the reasons for the increase in survival can be summarized as follows6,11,13,19,27,33 - 35 ) ; 1 ) early detection , 2 ) close follow - up , and 3 ) development of advanced treatment modalities - en bloc resection technique , effective chemotherapeutic agents , and sophisticated radiation delivery technique . the development of advanced diagnostic techniques leads to early detection of the disease , which implies that most of patients are diagnosed without distant metastasis11,13,34 ) . close follow - up results in early detection of recurrence , leading to survival prolongation . technical improvement in treatment modalities increased the survival . in surgical method , rao et al.27 ) compared survival rates in en - bloc spondylectomy and intralesional resection for patients with spinal sarcoma ( including metastatic sarcoma ) . patients undergoing en - bloc resection had a median survival of 26.2 months , and those with intralesional resection had a median survival of 18.6 months . teng et al.35 ) conducted similar research targeting the patients with mfh of the spine . compared to the 14 months median survival in debulking surgery group , that of the en - bloc resection group was 25 months . both studies showed that en - bloc spondylectomy could improve tumor control and survival rate . in addition , the radiation therapy such as stereotactic radiosurgery and tomotherapy was developed and diversified , excellent local tumor control could be achieved without radiation injury to adjacent spinal cord6,19,33 ) . it would be the best to compare the survival period based on each histologic type . however , it was impossible to compare individual histology , because the number of patients in each group was low . although mfh is different from osteosarcoma in pathological finding ( no tumor bone production ) , it is considered to be similar in clinical course and response to chemotherapy26 ) . even if no significant difference was found in three groups , we assume that if more cases could be collected enough to compare individual histologic type , meaningful difference might be produced . present analysis showed that overall survival was 60 months , which is varying depending on histology and recurrence rate is so high . close follow - up is required because recurrence could be within two or three years from initial diagnosis .