[pazimzadeh]

Antigen-specific immune responses against cancer cells usually involve clonal expansion (aka rapid division) of immune cells once co-stimulation has been achieved. This is often hindered by chemotherapy, although in the best case scenario, if the chemo is effective then it can lead to antigen uptake by local immune cells (epitope spread) which leads to a cascade of immune activity to clear the tumors.

I know that I am oversimplifying. However, generally chemotherapy works by killing rapidly dividing cells, such as cancer cells, hair cells, bone marrow progenitor cells, and immune cells at the tumor site. So yes, it does often functionally destroy/reboot the immune system. If you know of a chemo combo for solid tumors which doesn't lead to neutropenia or other functional immune depletions, please let me know.

[lostapathy]

Right, I'm not arguing the basic mechanism here. I'm just saying that every course of chemo does not completely wipe out your immune system, either. Dosage and cycling of the chemo matters, and even then your body reacts differently from cycle to cycle. Chemo is scary, but not because it completely kills your immune system every time.

My cousin and I had different cancers. Both of us had cisplatin. At the dose I had, my hair was gone. He hardly lost any hair and wasn't even that sick.

We also have drugs to offset the immune problems by sending your bone marrow into overdrive. My first cycle of cisplatin knocked my ANC to effectively zero. I was given additional meds on subsequent cycles and didn't have that problem again. (Said drugs are expensive and give you a special kind of bone pain that's hard to describe, so are apparently not given unless you have problems).