Could you briefly review the major side effects of the chemotherapy regimens? Which are most bothersome to patients?
FOLFOX has some side effects, with the most notable being sensory neuropathy, a phenomena where for the first 3 to 5 days after getting oxaliplatin, they will notice a sense of pins and needles in their fingers if they touch something cold. It's obviously reversible and it usually dissipates 3 to 5 days after chemotherapy. Rarely do patients ever quit FOLFOX due to that side effect.
The other important thing to note is a more cumulative, sensory neuropathy that occurs with months of oxaliplatin administration, where they start complaining not of episodic, but of longer term persistent numbness in their fingers and toes. Were that to happen, then certainly we would consider initial dose reduction of oxaliplatin, and thereafter discontinuing oxaliplatin. In the context of patients with metastatic disease, we almost never give more than 12 cycles of oxaliplatin, such that if they are continuing to do well on FOLFOX and they're approach 8, 10, 12 cycles, that's a circumstance where we're likely to stop the oxaliplatin and just continue the 5FU and the bevacizumab with the idea that you could reintroduce oxaliplatin, were there to be progression.
The other side effects we see with FOLFOX are common to most chemotherapies, namely some fatigue, some occasional reduction in blood counts, nausea which is usually well-controlled, rare events of diarrhea. So really the neuropathy is the one where patients would notice.
In contrast to FOLFIRI, which is an irinotican-based regimen, we don't see neuropathy, but the concern about irinotican that we're aware of is the issue of gastrointestinal side effects, which frankly have been overplayed. When irinotican was first developed, there were very high rates of diarrhea associated with the drug because we used schedules and doses that we no longer apply in the FOLFIRI regimen. So the rates of significant diarrhea for FOLFIRI are in the rage of 11% to 13%, sometimes less, and usually handled quite well with standard remedies.
Unresectable Colon Cancer: Case 1
68-year-old man was diagnosed with advanced, unresectable colon cancer has just started treatment with FOLFIRI plus bevacizumab.