Abstract 1120P
Background
Chemotherapy (CTx) is often used in mPPGL pts. Yet, prognostic and predictive factors associated with response to CTx in mPPGL remain unknown.
Methods
Multicenter retrospective study of adult mPPGL pts treated with first or second-line CTx across 7 Latam hospitals. Primary endpoints were radiological response according to investigators assessment and overall survival (OS) from date of mPPGL diagnosis. Prognostic and predictive factors evaluated for OS and response were respectively: Ki67 tumor immunohistochemistry (IHC) expression, functional imaging tests, tumor functionality and primary location, timing of metastases (synchronic x metachronic). Unadjusted log-rank test was used to compare OS by prognostic factors. Chi-square or Fisher-exact test was used to compare binary variables. P 0.05 were deemed significant.
Results
From 1982 to 2018, 25 of 63 mPPGL pts were eligible: 52% was male, median age was 39 years (20 - 61), 13 (52%) had family history of PPGL, 13 (52%) had functioning mPPGL. PPGL arose from supradiafragmatic, intrabdominal or adrenal glands in 5 (20%), 11 (44%) and 9 (36%) pts, respectively. 22 pts had data on ki67: median value was 10%, with 9 (40%) cases with ki67; 23 (92%), 24 (96%), 25 (100%) pts performed PETGa68, FDG-PET and MIBG scan: 8 (35%), 13 (54%), 16 (64%) had positive uptake, respectively. Cyclophosphamide, vincristine and dacarbazine (N=11; 44%) was the most common CTx. 20 pts were evaluable for response: 11(55%) had stable disease and 7 (35%) had upfront progression. Either MIBG (p=0.35), 18-FDG-PET (p =1) or PETGa68 uptake (p= 1) or Ki67 (cut off 10%; p=0.1) were associated with response from CTx. In a median follow up of 77 months, median OS was 37 months. Either tumor functionality (p=0.3), primary tumor location (p=0.6), Ki67 (cut off 10%), timing of metastases (p=0.4) or positive uptake on FDG-PET (p=0.5), on PETGa68 (p=0.1) or on MIBG (p=0.4) influenced OS. Numerically longer (nearly double) OS was observed in pts with positive MIBG, negative PETGa68, infradiaphragmatic or metachronic mPPGL.
Conclusions
Functional imaging tests (MIBG, FDG-PET, PETGa68) and tumor Ki67 IHC expression did not influence response from CTx or OS in pts with mPPGL.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.