does morphine promote tumor growth?

I've often wondered about morphine and opiates and there relationship to tumors. This is one theory (based on mouse data):

http://cancerres.aacrjournals.org/cgi/cont...ract/62/15/4491

Keep in mind that some studies show that morphine and its stress reduction may shrink tumors

There is an alternative (a rat study)
: tramadol

http://www.ncbi.nlm.nih.gov/entrez/query.f...6&dopt=Abstract

and a comparison between morphine and tramadol in Immune systems

http://www.anesthesia-analgesia.org/cgi/co...tract/90/6/1411

Al

Since my mets keep moving around and I take Morphine, I've occasionally wondered if this could be a factor. It seems like I read a year ago that it could. Any other info would be appreciated.

The same thing for anti-depressants.

Love and light,

Lisa