Adrenocortical cancer is one of the most aggressive endocrine
malignancies. Growth through the
capsule or accidental release of
cancer cells during surgery frequently results in metastatic disease. We investigated the antitumoral effect of 2 adrenocorticolytic compounds,
O, P'-DDD and
MeSO2-DDE, in the adrenocortical cell line H295R both in vitro and as a xenograft model in vivo. H295R cells were injected s. c. in nude mice.
O, P'-DDD,
MeSO2-DDE, or oil (control) was administered i. p., either simultaneously with cell injection at day 0 (mimicking adjuvant treatment), or at day 48 (established
tumors). Accumulation of PET tracers [ (11)C]
methionine (MET), [ (11)C]
metomidate (MTO), 2-deoxy-2-[ (18)F]fluoro-
d-glucose (FDG), and [ (18)F]-
l-tyrosine (FLT) in the aggregates were assessed +/-
drug treatment in vitro.
Tumor growth was significantly inhibited when
O, P'-DDD was given at the same time as injection of
tumor cells. No significant growth inhibition was observed
after treatment with
O, P'-DDD at day 48. A significant reduction in FLT uptake and an increased FDG uptake, compared to control, were observed following treatment with 15 microM
O, P'-DDD (p<0.01) in vitro.
MeSO2-DDE (15 microM) treatment gave rise to a reduced MET and an increased FLT uptake (p<0.01). Both compounds reduced the uptake of MTO compared to control (p<0.01). Treatment with
O, P'-DDD simultaneously to inoculation of H295R cells in mice, imitating release of cells during surgery, gave a markedly better effect than treatment of established H295R
tumors. We suggest that FLT may be a potential PET
biomarker when assessing
adrenocortical cancer treatment with
O,P'-DDD. Further studies in humans are needed to investigate this.