Characteristics and Treatment Patterns of Patients with Advanced Soft Tissue Sarcoma in Korea

Abstract

Purpose: A soft tissue sarcoma (STS) is a rare type of cancer, accounting for 1% of adult solid cancers. The aim of the present study is to determine the incidence of localized and advanced STS in Korean patients, their treatment patterns, and the survival of patients by disease status.

Materials and methods: The STS patient cohort was defined using National Health Insurance Service medical data from 2002 to 2015. Incidence, distribution, anatomical location of tumors, survival rates (Kaplan-Meyer survival function) and treatment patterns were analyzed by applying different algorithms to the STS cohort containing localized and advanced STS cases.

Results: A total of 7,813 patients were diagnosed with STS from 2007 to 2014, 4,307 were localized STS and 3,506 advanced STS cases. The total incidence of STS was 2.49 per 100,000 person- years: 1.37 per 100,000 person-years for localized STS and 1.12 per 100,000 person-years for advanced STS. The 5-year survival rate after diagnosis was 56.4% for all STS, 82.4% for localized, and 27.2% for advanced STS. Half of the advanced STS patients (49.98%) received anthracycline-containing chemotherapy as initial treatment after diagnosis.

Conclusion: This study provides insights into localized and advanced STS epidemiology, treatment patterns and outcomes in Korea, which could be used as fundamental data in improving clinical outcomes of STS patients in the future.

Keywords: Advanced soft tissue sarcoma; Epidemiology; Korean population; Modality; Treatment pattern.

Fig. 1.

Taxonomy of soft tissue sarcoma (STS) patients by treatment patterns. Localized and advanced cases were defined using a diagnostic algorithm. OP, only surgery; RT, only radiotherapy; Pre/Post-OP, surgery in combination with pre/postoperative treatment; CTx/CCRT (systemic treatment), chemotherapy±radiotherapy; CD (clinical deterioration < 1 year), patients who died within a year of diagnosis; Pre-Obs, patients who received surgery with preoperative treatment followed by observation; Pre-Tx, patients who received surgery with preoperative treatment followed by any treatment for cancer (chemotherapy, radiotherapy or surgery) 1 year after the initial surgery; Pre-Sys CTx, patients who received surgery with preoperative treatment followed by systemic chemotherapy 1 year after the initial surgery; Pre-Local Tx, patients who received surgery with preoperative treatment followed by local treatments 1 year after the initial surgery; Post-Obs, patients who received surgery with postoperative treatment followed by observation; Post-Tx, patients who received surgery with postoperative treatment followed by any treatment for cancer (chemotherapy, radiotherapy or surgery) 1 year after the initial surgery; Post-Sys CTx, patients who received surgery with postoperative treatment followed by systemic chemotherapy 1 year after the initial surgery; Post-Local Tx, patients who received surgery with postoperative treatment followed by local treatments 1 year after the initial surgery; CD-OP, patients who received only surgery and died within a year of diagnosis; CD-RT, patients who received only radiotherapy and died within a year of diagnosis; CD-Pre/Post-OP, patients who received surgery with pre/postoperative treatment and died within a year of diagnosis; CD-CTx/CCRT, patients who received systemic chemotherapy and/or radiotherapy and died within a year of diagnosis; CD-No Tx, patients who did not receive any treatment and died within a year of diagnosis. ^a) 1 Year; the 1-year period was chosen because in clinical practice adjuvant therapy usually lasts about 1 year after surgery in Korea.

Fig. 2.

Annual incidence cases by subgroup. STS, soft tissue sarcoma.

Fig. 3.

Incidence cases by age and distribution by subgroup. STS, soft tissue sarcoma.

Fig. 4.

Incidence rate by sex and age.

Fig. 5.

Kaplan-Meier curve of overall survival. STS, soft tissue sarcoma.

Fig. 6.

Kaplan-Meier curve of overall survival by treatment modalities in advanced soft tissue sarcoma (STS). The cases of CD (clinical deterioration < 1 year) were included in the relevant groups according to the modalities. ‘With surgery’ (n=1,789)=‘Pre-Tx’ (n=1,396)+‘Post-Tx’ (n= 60)+‘CD-Pre/Post-OP’ (n=333). ‘Without surgery’ (n=956) =‘CTx/CCRT’ (n=657)+‘CD-CTx/CCRT’ (n=299). OP, only surgery; CTx/CCRT, chemotherapy±radiotherapy; PreTx, patients who received surgery with preoperative treatment followed by any treatment for cancer (chemotherapy, radiotherapy, or surgery) 1 year after the initial surgery; Post-Tx, patients who received surgery with postoperative treatment followed by any treatment for cancer (chemotherapy, radiotherapy, or surgery) 1 year after the initial surgery; CTx/CCRT, patients who received only chemotherapy with or without radiotherapy.