History: Originally, there was considerable controversy as to whether exposure to Agent Orange resulted in an increased risk of numerous Cancers, including of course, Prostate Cancer (PCa).
Vietnam veterans were now composing a substantial portion of the age-related segments of the general population that were subject to naturally acquiring PCa. Along with very "mixed", and often conflicting Study results, there was no clear-cut answer to the question. Additionally, if it was thought to be a cause, how would it be determined which individual service men were actually physically exposed to Agent Orange during their active duty?
Finally, the controversy was pragmatically resolved by a VA declaration, that it would be ASSUMED that all service men,many years later acquiring PCa, whose records could establish that they had physically served in the Vietnam war theater, would be PRESUMED to have had Agent Orange exposure that caused their PCa.
Realistically, this was a "politically correct" decision, more than one clearly supported by scientific evidence, but due to the factors stated above, it appeared to the decision-makers that this was the most practical and expedient solution to a growing controversial issue, as the men effected continued to age.
As a result, a geographical "war zone" area (and time-frame) was established, that constituted the service area in which one had to have served for AUTOMATIC approval as "cause and effect" of their later PCa diagnosis.
Because of the volume of the such applications, it can take a while for such applications to be finally approved, but it is the qualification of time and location of service that is being checked and not any actual exposure to presumed cancer causing agents that is involved. Approval normally starts at 100% disability and is re-evaluated later, following treatment for any residual morbidity and is usually permanently adjusted downward, unless diagnosed with very advanced disease.
Once approved, reimbursement is paid retroactive to the date of application, so a potential beneficiary needs to be patient, since delays are common. Hope this history helps understand the procedure. - John@newPCa.org (aka) az4peaks