Evaluation Of Prognostic Factors For Liposarcoma And The Preliminary Report Of Genetic Testing

Objective:The clinical features and prognosis of patients with liposarcoma(LPS)were analyzed retrospectively and the factors related to the prognosis of these patients were determined by statistical analysis.At the same time,the application of newly developing genetic testing technique in the treatment of liposarcoma was explored.Methods: 78 patients with liposarcoma who treated in our hospital from December 2009 to March 2017 were reviewed.Prognostic factors of LPS patients were analyzed by using progression free survival(PFS)and overall survival(OS)as prognostic criteria.Univariate and multivariate analyses were performed to examine factors affecting clinical outcomes.In order to explore the application of genetic testing in the treatment of liposarcoma patients,we performed genetic testing on liposarcoma patients who were admitted to our department from May 2018 to November 2019 and willing to undergo genetic testing.Results: There were 41 males and 37 females enrolled with average age of 60.5 ±13.4 years(range from 18 to 85 years).Among the 78 LPS patients,27 of them were welldifferentiated liposarcoma,13 of them were myxoid liposarcoma,35 of them were dedifferentiated liposarcoma and 3 of them were pleomorphic liposarcoma.Lesion location distribution: 40 in extremities,38 in retroperitoneal.21 cases were treated with radical excision,57 cases were treated with marginal resection.After surgery 7 patients were treated with radiotherapy and 9 patients with chemotherapy.43 patients had local recurrence(extremities 9/retroperitoneal 34),18 patients with metastasis(extremities 4/retroperitoneal 14).The PFS rate was 44.8% and OS rate was 55.1%.Multivariate Cox regression analysis showed that the location of tumor was the independent correlation factor of PFS,while the histological subtype and metastasis were the independent correlation factor of OS.Kaplan-Meier survival analysis showed that radiation therapy can improve the PFS of myxoid liposarcoma(34.6 months vs28.3 months,P<0.05).A total of 4 patients with liposarcoma were tested for gene from May 2018 to November 2019,2 myxoid liposarcoma and two dedifferentiated liposarcoma.The results suggested that there were mutations in FUS,PIK3 CA,PTEN and TERT genes in patients with myxoid liposarcoma,while the mutations of FUS and PTEN genes suggested that this patient may benefit from the treatment of Copanlisib,Evimostr or Tamsirolimus.The test of dedifferentiated liposarcoma suggest that a patient with CDK4 mutation may benefit from palbociclib.What's more the detection of dedifferentiated liposarcoma patients showed that there was a variation of TP53 embryo line and Li-Fraumeni syndrome,and the mutation was also found in his daughter.TERT mutation was found in 3 of the 4 patients.Conclusion: The location of the disease is an independent factor affecting the PFS in LPS patients.Retroperitoneal liposarcoma is more prone to relapse and metastases.OS was influenced by pathological subtype and metastasis.Radiotherapy can prolong the PFS of the patients with myxoid liposarcoma.Genetic testing can be used to detect the number and types of gene mutations in patients,which has certain reference value in the follow-up treatment of patients,especially in patients with advanced liposarcoma.Since there are many types of gene mutations in patients with liposarcoma,further study is needed.