Speculation about chemo-induced anemia (and possibly leukopenia as well)

[Hopeful]

Here is a link to an opinion piece in the latest New England Journal of Medicine on weighing the dangers of these drugs:

http://content.nejm.org/cgi/content/...2445?query=TOC

Of particular interest for this thread:

" The mechanism underlying the enhanced growth of tumors withhigher doses of ESAs remains uncertain. There is good evidencethat hypoxic tumors resist chemotherapy and radiotherapy. Thebiology of tumor hypoxia, with enhanced cell signaling throughthe Akt–mammalian target of rapamycin (mTOR) axis andsubsequent up-regulation of hypoxia-inducible factor 1, is whatinspired the clinical trials in which ESA treatment was combinedwith radiotherapy, cytotoxic chemotherapy, or both in an attemptto overcome hypoxia-induced resistance. But another possibilityis that certain tumor cells have erythropoietin receptors thatstimulate cell growth when they are bound by erythropoietinor an erythropoietin-like ligand. Squamous-cell lung cancer,squamous-cell tumors of the head and neck, and breast adenocarcinomasseem to express erythropoietin receptors, but such receptors'role, if any, in tumor growth is unclear. Henke et al. showedthat erythropoietin receptors were expressed by two thirds oftumors in their study and that expression of such receptorsin erythropoietin-treated patients was associated with shortersurvival.⁵ Conversely, in vitro studies have shown that stimulatingerythropoietin receptors in cell lines from head and neck cancerand breast cancer causes the death of cells, though the questionablequality of the reagents used to detect erythropoietin receptorsmust be considered in interpreting these data."

Hopeful