At least 4,500 cancer patients (29%) have waited six months or more to find out whether they will even be awarded their disability benefit Personal Independence Payment (PIP) after claiming, according to estimates by Macmillan Cancer Support.
The research, which surveyed 2010 cancer patients, revealed that a quarter (25%) of those who have started their claim are currently stuck in the system as they wait at least six months for the initial assessment.
These delays are in addition to the lengthy three-month wait cancer patients face before they are even eligible to apply for PIP.
Under the previous system the average time taken to receive a decision about the Disability Living Allowance (DLA) took just 11 weeks. Now the process is taking far longer with cancer patients waiting an average of 19 weeks without receiving any decision, Macmillan said.
The report found over half (56%) found their finances took a hit with as many as two-fifths (40%) unable to adequately heat their homes.
Additionally, one in three (34%) felt the delays had resulted in mental health problems such as anxiety or depression
Nearly half (47%) of all cancer patients surveyed were dissatisfied with the overall process.
A third (33%) said this was because of the lengthy delays and almost a quarter (23%) blamed poor communication from the Department of Work and Pensions (DWP).
Some cancer patients found the PIP claims process and interaction with DWP so difficult, upsetting or time consuming that 2% stopped their claims entirely.
Duleep Allirajah, head of policy at Macmillan Cancer Support, said:
"Our report shows the real and shattering impact these PIP delays are having on cancer patients. It is unacceptable that people struggle to heat their homes, are saddled with debt or are left anxious or depressed because they are waiting so long for their much-needed benefits.
"These delays are a further blow to cancer patients who have to prove that they have been affected by their disease for at least three months before the state will consider them as eligible for help.
"The Government has a duty to ensure that the new disability benefit works at least as well as the old one and Macmillan is calling on them to reduce waiting times to 11 weeks as a matter of urgency."