One of the persistent issues nagging at John McCain's presidential candidacy has been that of his age. Although McCain appears vigorous and maintains a full aggressive daily schedule, there is a perception that at 72 (when and if elected), he just might not be up for the job.

Lately, for reasons mostly unrelated to the age factor, McCain's poll numbers have been slipping badly. But recently a new senior-citizen candidate (almost officially announced) has arrived on the scene quickly surpassing McCain's dwindling ranking in the national polls.

That candidate, of course, is Frederick Dalton Thompson, who will be 65 in August. Thompson would be a little over 66 were he to assume the presidency (another assumption, of course). 66 is not old in today's world. Heck, it might even be the new 56. And remember, Ronald Reagan was a robust 69 when he took the oath (we won't argue here how that all turned out).

But Fred D. Thompson has a few problems beyond the arguable issue of his semi-advanced years.

Thompson, as is known but rarely discussed, has cancer. Non-Hodgkin's lymphoma (NHL) actually. Probably not the worst or most dangerous of all cancers, but cancer nonetheless. To the press, Thompson likes to downplay his disease and its ramifications.

Here's a quote from Thompson from the Neal Cavuto show on Fox: "I have had no illness from it, or even any symptoms. My life expectancy should not be affected. I am in remission, and it is very treatable with drugs if treatment is needed in the future — and with no debilitating side effects."

Well, as it turns out, this may or may not be the case.

Thompson's cancer is reportedly "indolent". Indolent (low-grade) non-Hodgkin's lymphoma is generally not curable, but is typically slowly progressive and responds temporarily to therapy. (I'm no cancer expert, this is from various medical websites.) According to The National Cancer Institute: "NHLs can occur at any age and are often marked by enlarged lymph nodes, fever, and weight loss."

Thompson's obvious change in appearance is the thing that started me thinking in the first place about his ability to serve as president. (I'm talking beyond all the Dem/Pub partisan stuff here.) To me, he looks terrible lately. Gaunt, haggard, gray....like he's aged about ten years in the past two. He says he's suffering no symptoms, but you have to wonder. As Roosevelt with his polio and Kennedy with his various pain problems, the less said the better about human frailty when it comes to informing the public.

We all hope that his cancer never becomes aggressive and devastating. There are only a very select few in the world I might wish that horror upon.

But here are some disturbing stats, also from the National Cancer Institute web page, regarding the estimated new cases and deaths from non-Hodgkin's lymphoma in the United States in 2007:

New cases: 63,190
Deaths: 18,660

Those numbers do not look very good percentage-wise for anyone with the disease .