White sugar; can be applied to salt, brown sugar, sweetener, but most usually to white sugar, on the basis that "everything" - sugar, sweetener, coffee, red meat, water, oxygen and light will cause cancer (eventually).
Taking all available information into account, the only way to avoid dying of cancer is to forswear all food and drink, and shut yourself in an airtight lead box. You won't die of cancer. You will still die, and quite quickly, but it won't be of cancer.
"Coffee's done. Milk and sugar ?"
"No milk, but gimme two spoons of cancer crystals".