It’s safe and healthy for general people to have sunbath under mild sunlight in the morning or late afternoon. However, it may be hard to say when it comes to cancer patients.
Ultraviolet radiation is one of the main causes of skin cancer, and sunlight exposure might worsen existing skin cancer treatment, so patients with skin cancer are commonly forbidden to be in the sun.
As with patients with other types of cancer, sunlight exposure might do good to their cancer treatment, because sunlight triggers the production of vitamin D.
A study published in the Journal of Oncological Sciences found that more sunlight exposure may improve the overall survival of patients with pancreas cancer.
In the study, patients with pancreatic cancer living in the state with more sunlight exposure had higher overall survival. This suggests that more sunlight exposure may bring better prognostic effects.
Researchers from the Brookhaven National Laboratory in the United States also found that moderate exposure to the sun significantly increased the survival rate for patients with colon cancer, prostate cancer, lung cancer, and breast cancer who were deficient in vitamin D, and it is particularly true for patients living in high-latitude countries.
The patients living in sunny Australia had 20~50% higher survival rates than those living in high-latitude Norway.
These studies show the positive benefits of sunlight exposure, while there are still some controversial study results.
A study published in the journal shows no differences in survival rates for sunlight exposure among patients with non-small cell lung cancer.
Generally speaking, proper sunlight exposure is beneficial for cancer patients (excluding patients with skin cancer). However, cancer patients shall still be cautious. Strong sun exposure between 10:00 am and 3:00 pm shall be avoided.
Cancer patients who are receiving chemotherapy shall consult their doctors before starting short sunbathing because some chemotherapy or radiotherapy can make them more sensitive to the sun.