Many cancer patients are dying, not because the treatments are not available, but because the initial physician failed to give the best possible treatment. Cancer is an unusual disease for many reasons - if you don't treat it properly the first time, often there is no second chance because cancer grows geometrically. Often one treatment precludes the proper  treatment from being given later. Doctors are humans and could make a mistake. Rarely is cancer diagnosed by an oncologist (It is generally diagnosed by an optometrist, gynecologist, urologist, dermatologist, GI, GP, etc.) and that doctor may not want to lose the revenue or admit that someone knows more than he does. 

Lives will be saved by reducing physician mistakes, which in cancer equate to death instead of cure.  These mistakes are caused by ignorance or lack of knowledge, misjudgment, carelessness, ego, greed, or lack of time or proper tests.  No one is in favor of mistakes, but as long as physicians are human, they all make mistakes.  A second or third opinion can do nothing but reduce the number of mistakes. 

The National Cancer Policy Board, in their 1999 report, recommended ensuring the following elements of quality care for each individual cancer: 

• that recommendations about initial cancer management, which are critical in determining long-term outcome, are made by experienced professionals; 
• an agreed upon care plan that outlines goals of care; 
• access to the full complement of resources necessary to implement the care plan;
• policies to ensure full disclosure of information about appropriate treatment options.