Skin cancer patients are vulnerable to other cancers too.
Previous researches also suggest that one type of cancer raises the risk of developing another
Now experts have found people treated for melanoma were more than twice as likely to develop other, unrelated cancers than the general population.
The risk was also elevated - although not as much - for patients with other forms of skin cancer.
The study, led by Queen's University Belfast, features in the British Journal of Cancer.
The researchers analysed data from the Northern Ireland Cancer Registry, including 1,837 patients with melanoma, the most aggressive form of skin cancer, and 20,823 patients with less aggressive forms of the disease.
Patients with non-melanoma skin cancer were up to 57% more likely to develop another type of cancer than people in the general population.
They were almost twice as likely to go on to develop melanoma and had an increased risk of smoking-related cancers.
But the risk of subsequent cancers was even higher in the melanoma group - more than double that of the general population.
Researcher Professor Liam Murray said there were several possible explanations for the link.
He said: ''Sun exposure is an important risk factor for all types of skin cancers so patients who have had one type of skin cancer may be more likely to develop other types as well.
''Alternatively a new skin cancer may be more likely to be detected in patients who are monitored following their first diagnosis of skin cancer.
''The increase in smoking-related cancers may be because smoking predisposes to skin cancer as well as other cancers or because people who smoke may be more likely to have generally unhealthy lifestyles including excessive sun exposure.''
Sara Hiom, of the charity Cancer Research UK, told BBC: ''We know that lifestyle factors such as excessive UV exposure, smoking, being overweight and drinking too much alcohol can increase the risk of cancer.
''These important findings could help doctors target health information more accurately to people who have been treated for skin cancer to help them reduce their risk of developing a second cancer.''