why chemotherapy with CHOP are given in 6 cycles

Hi Yenni-

I am not a chemo expert, so I won't be surprised if someone else weighs in here, but I did find an article from The Lancet - Oncology that studied 6 versus 8 rounds and with or without additional drugs. Here is their conclusion:

Interpretation
Six cycles of R-CHOP-14 significantly improved event-free, progression-free, and overall survival over six cycles of CHOP-14 treatment. Response-adapted addition of chemotherapy beyond six cycles, though widely practiced, is not justified. Of the four regimens assessed in this study, six cycles of R-CHOP-14 is the preferred treatment for elderly patients, with which other approaches should be compared. (http://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(08)70002-0/abstract)

We have a section on non-Hodgkins lymphoma that you might find helpful as well: https://www.empowher.com/condition/non-hodgkins-lymphoma. I hope this helps a bit.

Thank you for writing.