How effective can adjuvant therapy be?

Variable: The effect of adjuvant (post surgical) therapy (chemotherapy, endocrine therapy, etc) is variable. For some early cancers such as stage ii colon cancer the benefit may not be worth the risks. For breast cancer we can attempt to better quantify the potential benefits with a program (adjuvant online!). The doctor and patient need to determine the patient value of the numbers to individualize care.

Very: Adjuvant means "additional", so adjuvant therapy is something given in addition to surgery to treat cancer. Some adjuvant therapies are extremely effective. For instance, Herceptin (trastuzumab) in her2+ breast cancer decreases risk of recurrence by almost 50%! that's about the largest effect we ever see with adjuvant therapy. Typically, we are looking at gains of 10% or less.