BACKGROUND: Soft tissue sarcoma (STS) is a rare malignancy with an annual incidence rate of < 5 cases per 100,000 persons; outcomes for metastatic STS (mSTS) are poor. A targeted literature review was conducted to quantify the efficacy/effectiveness of current mSTS therapies.
METHODS: A structured search based on the population, intervention, comparator, outcome, study type (PICOS) framework was performed on articles (2009–2019) in MEDLINE, Embase, and Cochrane Central. Limited congress searches (ESMO, AACR, ASCO 2016–2018/2019) were also conducted. Clinical trials (CT) and observational studies (Obs) involving patients (pts, any age) with advanced mSTS receiving any pharmacological intervention were included. After screening, selected efficacy (CT) or effectiveness (Obs) endpoints (including progression-free survival [PFS], overall survival [OS], overall response rate, and duration of response) stratified by line of treatment (LOT, if available) were extracted.
RESULTS: Overall, 85 studies (56 CT, 29 Obs) met inclusion criteria; study size was 20–4,274 pts. PFS and OS (from 70 studies) were reported for pts with mSTS treated with a wide range of interventions including doxorubicin, trabectedin, pazopanib, and gemcitabine. Across any LOT, median PFS ranged 1.5–9.3 months in CT and 2.1–11.0 months in Obs; ranges were 5.7─28.8 months and 7.0─38.6 months, respectively, for OS. Median PFS and OS were generally lower with later (vs initial) LOT; few studies assessed ≥4 LOT (Table). Outcome data (any LOT) for trabectedin and pazopanib (the only approved targeted mSTS treatments) are shown in Table.
CONCLUSIONS: This review of the efficacy/effectiveness of current treatments highlights the unmet clinical need for therapies that improve survival outcomes in pts with mSTS. Results may be influenced by small sample size, pt population, and care improvements over the period studied.
