A "worrying" number of patients are waiting more than the recommended six weeks for key diagnostics tests that detect cancer and other diseases, according to a charity.
Macmillan Cancer Support has raised concerns about the delays, which it said have reached a six-year high.
Latest NHS England figures show that 16,981 patients were waiting six weeks or more for 15 diagnostic tests including MRI and CT scans, audiology assessments or cardiac echos - or 2.2% of all of the patients waiting for such tests.
In April 2008, just 2,904 patients were waiting for these checks.
The British Medical Association (BMA) has said the profession must "guarantee" that older cancer patients "are treated with care and respect" after claims some are denied treatment solely on their age.
It is important that all healthcare professionals ensure that patients are treated on the basis of their clinical need.
With an increasingly ageing population, it should be a key part of medical professionalism to guarantee that older patients are treated with the care and respect they deserve.
Macmillan Cancer Support said health workers should ensure decisions over cancer treatment take into account a patient's physical and mental health and not be based on age alone.
The National Cancer Intelligence Network (NCIN), which carried out the research into pensioner survival rates alongside the charity, joined the call for wider assessment.
NCIN's clinical lead Dr Mick Peake said: "It is vital that all patients receive the best and most effective treatment based on the nature of their cancer and their fitness for treatment and that chronological age alone is not the deciding factor.
"We know that cancer survival rates in older patients in many other countries are better than in the UK and ensuring optimal treatment at all ages is the way of tackling this issue."
A leading charity has warned cancer patients are being "written off" as being too old for treatment, saying assessments are ignoring fitness levels to judge on age alone.
Macmillan Cancer Support spoke out after finding more than 130,000 pensioners who have been diagnosed with cancer have gone on to live for at least a decade, including 8,000 patents over the age of 80.
The charity's chief executive, Ciaran Devane, said: "With a proper assessment and appropriate treatment, our research shows that many older cancer patients can live for a long time and can even be cured.
"The barriers to getting treatment - which include age discrimination and inadequate assessment methods - must be tackled now so more older people can survive cancer and live for many years."
The care bill already contains proposals designed to support carers, the care minister has said.
Norman Lamb agreed with Macmillian Cancer Support, that carers made "a huge contribution" to the UK, but continued with plans to have them identified by the local council, rather than the NHS.
Carers make a huge contribution to society and we want to do all we can to support them.
We agree that there needs to be better joint working and proposals already in the care bill will mean that local authorities will have to co-operate and work closely with the NHS to identify and support carers.
We have also provided £400 million to the NHS for carers breaks and given over £1.5 million of funding to help develop initiatives with GPs, nurses and carers organisations to train people to help support them in their caring roles.
Serious changes should be made the to care bill, currently making its way through Parliament, to better support carers, a leading health charity has said.
Ciaran Devane, chief executive of Macmillan Cancer Support said it was "nonsensical" that the care bill places a legal duty solely on local authorities to identify and support cancer carers.
Caring is a huge responsibility taken on out of duty and love. Families and carers are the backbone of society and they deserve to be supported.
Without support, cancer carers can go beyond breaking point which is bad for them and their loved one but is also costly to the NHS and ultimately to the taxpayer.
By identifying cancer carers and explaining what information and support is available, health professionals can vastly improve their quality of life and help them to continue caring - which is what they want to do.