How would you treat a patient with recurrent DLBCL 15 years after definitive treatment of initial de novo disease with R-CHOP?  

As a new primary DLBCL, but with previous exposure to 6 cycles of doxorubicin, I would only give RCHOP x 2, then RCEOP x 4. If interim PET showed a poor response, I would switch to a CAR T-cell therapy as 2L therapy.