愛污传媒

Republican presidential candidate John McCain has maintained that his age and his skin cancer history will not affect his ability to fulfill his duties should he win the U.S. election on November 4.

But in a commentary published in this week's edition of the medical journal The Lancet, Dr. John Alam says McCain would only have a one in four chance of surviving 10 years after his melanoma diagnosis based on a common prognostic model.

McCain was diagnosed with melanoma more than eight years ago, in August 2000.

"Long-term risk of recurrence and mortality due to melanoma is potentially an important factor in the U.S. presidential race" because of McCain's age and health concerns, said Alam.

Experts have debated McCain's fitness to be president, and many pundits worry that his vice presidential running mate, the much-maligned Sarah Palin, will be left running the free world if McCain dies in office.

In his commentary Alam, a former Massachusetts physician and current consultant to the biotechnology industry, assesses McCain's battle with skin cancer.

Alam found several factors that would considerably elevate McCain's risk of death from the disease, including:

• His tumour was a cutaneous melanoma, which is one of the most high-risk skin cancer tumours.
• The tumour was 2.2 millimetres thick, which puts it in the second-highest risk category, and was not located on an extremity.
• McCain was more than 60 years old when he was diagnosed, and he is male.

Based on these factors, McCain would have a 12 per cent increased risk of death from melanoma in the remaining two years of his 10-year post diagnosis period, Alam said.

The risk would remain at 12 per cent for several years after, Alam said.

However, the model was developed before the advent of the sentinel lymph node (SLN) biopsy, which determines if the cancer has spread.

McCain had the SNL biopsy and was told his cancer had not spread.

Therefore, Alam concluded that "McCain's mortality risk due to melanoma is better but not eliminated, remaining at six per cent per year."

The health of the presidential and vice-presidential candidates has been at the forefront of this U.S. election campaign, particularly because at age 72 McCain would be the country's oldest president if elected.

To prove his physical fitness, McCain released more than 1,000 pages of medical records last spring.

The records proved that he is now cancer-free, has a healthy heart and normal blood pressure and that, like many men his age, he takes medication to keep his cholesterol in check.

While his Democratic opponent, Barack Obama, has also been found to be in good health, Obama is a former smoker who has struggled with is attempts to quit.

Obama's running mate, Joe Biden, had a life-threatening brain aneurysm in 1988 that required emergency surgery.

Biden's health records did not indicate that he is undergoing the recommended brain scans to ensure he does not develop a second aneurysm.

Otherwise, Biden is in otherwise good health. The 65-year-old also takes cholesterol medication, has an enlarged prostate and uses nasal sprays and allergy relievers for chronic sinusitis.