Mr Brown's proposals are part of wider plans for community health care
Every cancer patient in England will be offered free, one-to-one home care by specialist nurses if Labour wins the election, Gordon Brown has pledged.
In a speech to the King's Fund think tank, the prime minister also pledged access to home treatment for every cancer patient within five years.
Labour says this would save over £2.5bn a year by reducing hospital admissions.
But shadow health secretary Andrew Lansley called on ministers to say what they would cut to pay for the move.
The proposals on cancer treatment are expected to form part of a wider plan to give more patients the option of receiving chemotherapy, dialysis and palliative care without travelling to hospital.
But the Conservatives are sceptical, arguing that while they support specialist nursing, the plan could cost £100m.
Mr Lansley said: "We support the principle of giving every cancer patient their own nurse. But I am surprised that Labour are able to find money to fund this new pledge when they are planning to cut the NHS budget.
"Gordon Brown needs to make clear to patients which other schemes he plans to cut in order to fund this new initiative."
Details of the plan emerged as the prime minister promised reforms in the social care system to try to prevent the financial worry of old age.
In his regular Downing Street podcast, Mr Brown said people in middle Britain would benefit from "guarantees" over end-of-life care.
Free personal care for the elderly in England is likely to be one of the key planks of Labour's election strategy.
Mr Brown said: "It's not fair that so many people already struggling with the loss of independence - who have worked hard all their lives and saved for their retirement - are faced with the prospect of running down their savings or selling their homes to fund their care.
"Or that those seeing their parents and grandparents suffering from conditions like Alzheimer's and dementia not only have to watch as their dignity fades, but have the heartbreak made worse by the costs of getting support.
"So I am proud that we are about to bring forward a new system of social care that will directly benefit many families of middle Britain."
Mr Brown said there needed to be "firm assurances" for providing care to those who need it.
"In health, our support means offering guarantees, not gambles - including treatment within 18 weeks and being seen by a cancer specialist within two.
"We'll also ensure everyone has dignity and security in their old age."
The free personal care proposal was originally put forward by Mr Brown at Labour's conference, and is currently being debated in a bill before Parliament.
The bill, which would affect England, will not be implemented before the election. Scotland already has free personal care.
Praise and criticism
Ciaran Devane, chief executive of Macmillan Cancer Support, welcomed the plans.
He said personalised nurses perform a number of crucial roles, including helping patients understand the medical explanations for treatments, supporting them directly and helping them get the support they need.
"Specialist cancer nurses provide invaluable care and support from the point of diagnosis, throughout treatment and after," said Mr Devane.
"They also ensure the NHS puts the patient at the centre of their care, and adopts a joined up approach accordingly, whether its treating them at home, in the community or at hospital."
But the bill has attracted criticism from peers, local government and campaigners because a wider review of social care is also taking place.
It affects only about half of the 500,000 people receiving care in their own home - most of these are elderly, although some are people with disabilities.
On top of that, more than 400,000 living in care homes would not benefit from the bill.
Last summer, a Green Paper was published putting forward a series of proposals affecting the whole range of social services.
These include radical plans to impose charges, perhaps as much as a £20,000 bill payable on retirement.