The LRG responds to recent cancer cell coverage. Yesterday, there were a series of news stories reporting on an article published by Cooke et al inCancer Cell.  Unfortunately, the coverage gave misleading information which could suggest that patients should not take Gleevec (imatinib) or Sutent (sunitinib). Nothing could be further from the truth. The fact is—these drugs are extremely useful therapies for GIST patients.

In their article, Cooke and colleagues found that reducing the number of pericytes (cells that line the small blood vessels and provide structural support) either through genetic engineering or treatment with imatinib or sunitinib, caused the implanted tumor to shrink but increased metastases in mice. Thus, some internet stories interpreted this to mean these drugs make cancer worse in patients.  This is not what the study presented.
Important points:

  • This study was conducted on mice.
  • The study used a breast cancer cell line, which unlike GIST does not have KIT as a target.
  • Patients with metastatic GIST by definition already have metastases.  The positive direct anti-tumor effect of imatinib and sunitinib against GIST tumors far outweighs the possible negative effect of pericyte depletion. This has been demonstrated in numerous clinical trials that have found both a progression-free survival advantage and a huge overall survival advantage for patients taking these drugs compared to historical controls or to placebo. In fact, Gleevec and Sutent are proven to produce increased progression-free survival and overall survival in GIST. Treatment with imatinib alone triples survival times compared to historic controls.
  • Adjuvant treatment with longer periods of imatinib has been shown to increase survival compared to shorter periods (1 yr vs. 3 yrs). Surgery removes the primary tumor and micro-metastases have either already occurred or they have not. If a patient already has microscopic GIST, then treatment with imatinib prevents or dramatically reduces further cell proliferation, largely preventing further genetic damage. Simply put—if you have had surgery, even with clear margins, there may be a risk for recurrence due to some cancer cells that may remain. The risk associated with taking Gleevec or Sutent is much less than the risk of not taking them.
  • Assuming Cooke et al. are correct, the only theoretical area that might warrant further investigation is the issue of neoadjuvant treatments, which are currently not FDA approved.Should additional information become available from Novartis/Gleevec and Pfizer/Sutent we will supply this to our members. 

For inquiries, please contact LRG Communications Director, Erin Kristoff at (973) 837-9092 x117 or ekristoff@liferaftgroup.org

Erin Kristoff
Author: Erin Kristoff