Record numbers of cancer patients are relying on charity grants for essentials such as clothing and heating.
Macmillan Cancer Support said thousands of people struggle every year to cope with the financial cost of cancer, caused by issues such as being unable to work or needing special equipment.
More than 33,000 cancer patients relied on grants from the charity in 2014 - a record high. It paid out around £9.9 million worth of grants to help people on low incomes with cancer.
Half of the cancer patients (53%) needed the cash for clothing and fuel bills while the rest was spent on areas such as specialist equipment, stair lifts, beds to have downstairs, new bedding and transport to and from hospital.
The charity said people with cancer often need extra clothes because of weight loss or gain, abdominal swelling, colostomy bags or special bras if they have had a mastectomy.
Cancer treatment also causes people to feel the cold more, which can lead to soaring fuel bills.
Overall, at least 120,000 people relied on Macmillan for financial advice and support, including navigating their way through the benefits and tax credits system or receiving guidance on mortgage payments and pensions.
Lynda Thomas, chief executive at Macmillan Cancer Support, said: "The growing number of people with cancer turning to Macmillan with money worries is a stark reminder of the financial impact of a cancer diagnosis.
"Clothing and rising energy bills are just two of a number of costs people with cancer are burdened with at a time when on average their income halves and their outgoings rocket.
"People can face spiralling financial problems they don't know how to manage when they're already dealing with the gruelling physical and emotional consequences of cancer."
Macmillan is calling on the Government to reform its Welfare Reform and Work Bill.
Ms Thomas said: "The Government is proposing to reduce the benefits of people with cancer who are currently unable to return to work because they're not well enough by around £30 a week in the Welfare Reform and Work Bill.
"The Government must reconsider these plans or risk pushing the most vulnerable over the edge financially."
Paul Burks, 56, from Essex, was first diagnosed with multiple myeloma in 2010. In April this year he was told his cancer had returned.
He said: "My loss of earnings was huge - I went from a three-figure income to £67 a week. We had to extend the mortgage and my wife had to take over the full thing.
"I've not been able to work because of all the problems since my diagnosis and I've suffered from so many unexpected expenses. My wife came with me for treatment but it was impossible to come home every day because it was too costly for two people to do the journey for a week.
"My wife often sits there with her calculator dealing with the bank. Cancer has a devastating impact not only your body but on your finances too."