Mandela has prostate cancer

Mandela is busy mediating the peace process in Burundi

Former South African president Nelson Mandela has been diagnosed with prostate cancer.

A spokeswoman said the tumour was "microscopic" and should not reduce Mr Mandela's life expectancy.

No surgery is being contemplated for the 83-year-old elder statesman at the moment and he will receive a seven-week course of radiotherapy.

The Nobel peace prize winner was probably the world's best known political prisoner, spending 27 years in jail.

In 1985, while in prison, Mr Mandela was hospitalised for prostate surgery and had some tumours removed. They proved to be benign.

He then returned to jail, where he remained until his release in February 1990 - the key moment in recent South African history.

Still busy at 83

As president of South Africa between 1994 and 1999, he supervised its transition from white minority rule to full democracy.

Nelson Mandela being helped off a plane on Monday

He is now retired from active politics, but still maintains a punishing schedule.

He travels frequently around the world, often to collect achievement awards, and his extraordinary popularity remains undiminished.

After celebrating his birthday at the weekend, he was in Tanzania on Monday mediating a breakthrough in the Burundi peace process.

Three years ago, the Nobel peace prize winner married Graca Machel, the widow of the former president of Mozambique.

Mr Mandela remains a fit and generally healthy man, but is starting to appear more frail.

Prostate cancer rates rising

The prostate is a small gland lying close to the bladder.

This form of cancer is a common condition in elderly men and can usually be treated successfully, if it is detected at an early stage before it spreads to other organs.

It is the fourth most common global cancer, and may become the most common, as the world population ages.

Archbishop Tutu is another sufferer from the cancer in South Africa, where the incidence rate is 42.78 men per 100,000 of the population.

Just under 26 men per 100,000 of the population die from the disease.

For comparison, the same figures in the UK are 40.24, with a mortality rate is 18.5 per 100,000.