There was an increase of 2,700 in the number of deaths from less common cancers between 2010 and 2013, a report from Public Health England (PHE) and Cancer 52 has found.
The rise means these cancers, which account for 47% of diagnoses of cancer, account for 54% of deaths, up from 52% in 2007.
Less common cancers excludes lung, bowel, breast and prostate cancers, and the data combines figures from almost 280 forms of cancer.
The report, "Rare and Less Common Cancers: Incidence and Mortality in England, 2010 to 2013" was published by PHE and Cancer 52 to coincide with the National Cancer Intelligence Network (NCIN) conference in Belfast.
Cancer 52 is an umbrella organisation for over 80 organisations working to help those with less common forms of cancer.
Jonathan Pearce, chair of Cancer52 said: "The enormous initial task of preparing this data has been carried out by the NCIN team and robust incidence and mortality figures identified.
"The figures illustrate that although people are less likely to get a rare or less common cancer, if they do develop one they are more likely to die from it.
"Cancer52 calls on policy makers to more strongly address the inequalities and inequities that allow this scenario not only to continue, but to worsen."
Juliet Bouverie, director of services and influencing at Macmillan Cancer Support said: "These worrying figures show the true burden of being diagnosed with a rarer cancer in the UK.
"One of the reasons survival rates are particularly poor for people with rarer cancers is that signs and symptoms are difficult to spot, meaning people are more likely to be diagnosed late.
"Rarer cancers are less likely to appear as a lump and it's a difficult task for GPs to be aware of all of the varying symptoms for the hundreds of different rarer cancers.
"But improving survival rates alone won't help relieve the full burden that people with rarer cancers face.
"People with rarer cancers are more likely to say they've had a poor experience during a stay in hospital than those with common cancers and are also more likely to feel isolated because they know so little about their disease.
"It is simply not fair that someone with a rarer cancer should be worse off than those with more common forms of the disease."
Further Reading:
Amount of common cancers in under 45s found
Cancer patients 31% more likely to have a long term condition
