Chapter 19, Problem 3CS

CASE STUDY |Cancer-killing bacteria

Ralph, a 57-year-old man, was diagnosed with colon cancer. His oncologist discussed the use of radiation and chemotherapy as treatments for this cancer and explained that each of these therapies kills actively dividing normal and cancer cells, causing debilitating side effects. Ralph decided to carefully review his options and went for a second opinion to a cancer clinic at a major teaching hospital. There he learned that researchers in a synthetic biology program were testing the use of genetically modified E. coli that selectively invade and kill cancer cells, with no effects on normal cells. Ralph decided to participate in this trial, and at an appointment to learn about the details, he was informed that he would be part of a Phase III trial, comparing the effectsof the modified bacterial cells against conventional chemotherapy. As part of the trial, he would be randomly assigned to receive one or the other treatment. He was disappointed to learn this, because he assumed that he would receive the bacterial therapy.

Or should he enroll on the chance that he would receive therapy using the genetically modified bacteria and that would be more effective than conventional therapy?