Minogue, 44, who diagnosed with breast cancer in 2005, said she found it hard to feel positive while battling the disease, reported Daily Express.
"Sometimes when people say 'Be positive' you can't be positive all the time," she said.
Later on micro-blogging site, the singer, who attended the red carpet at the Beverly-Wilshire Hotel, wrote, "Thank you for an unforgettable evening (Entertainment Industry Foundation) and congratulations on all your good work.