Re: How doe's colonrectal cancer cause fistulas to form?

Dear Ms. Blodgett,
Sorry for the delay in my answer.  The answer to your question is 
relatively simple.  Cancer is basically a cell gone wild.  When these cells 
go wild it entails rapid growth.  Cancer cells can infiltate regular cells, 
pushing them out of the way.  In this way cancer cells can grow through the 
wall of a colon into the peritoneal (abdominal) cavity, the pelvis, or 
another organ such as the bladder or vagina. Because of the rapid growth of 
these cancer cells, they often outgrow their blood supply.  When this 
happens, the cells that are not receiving enough blood will begin to die.  
If the cells that die are in a part of the cancer that connects one section 
or organ of the body to another, a fistula (abnormal opening or connection) 
can form.  This is very dangerous to the patient because fecal matter is 
made up of mostly bacteria by the time it reaches the colon and infection 
can then occur.  A fistula can also occur from an organ to the surface of 
the body.  I hope this answers your question.  

Thank you for your interest in science.

Sincerely,

Sarah Martin Mason
Tulane University School of Medicine