Lady Gaga wants to use her voice to stand up to cancer

Lady Gaga has vowed to become a leading voice in the fight against cancer after losing her best friend to the disease.

The Born This Way superstar was left heartbroken on Thursday (18May17) after her former assistant Sonja Durham lost her five-year battle with the illness.

Gaga took to Instagram to pay tribute to Sonja, heaping praise on her close pal for her "unfathomable courage, strength, and positivity" while fighting the disease, and on Sunday (21May17), the singer posted a photo of the pair having a little fun as she reflected on the friendship she had treasured for the past decade.

"I don't know how to put a price on a friendship," Gaga began in the lengthy caption. "I'm not even sure how you can assess the size of its meaning, only really your heart truly knows and it's too special for words."

The hitmaker credited Sonja with helping her maintain her sanity after skyrocketing to fame, and encouraging her to "stay inspired no matter how scared I was".

"She knew all I cared about was the music. She made that ok," Gaga wrote, before admitting she is still "in shock", describing the loss as "being robbed of the last 10 years of my life, friendship and career with her". 

The singer then vowed to honour Sonja's memory by becoming a "warrior" and "a voice for cancer patients so the world can continue to improve the dialogue and the fight".

Gaga has been using cooking as a form of therapy as she tries to comfort Sonja's widower Andre and stepson Sante, and she revealed she called on her best friend to find her late aunt Joanne in heaven.

"I made them some food yesterday," she concluded the emotional post. "I will keep cooking. Cooking my soul until it understands this. Last thing I told her, 'Go find Joanne, Sonj.' Somehow I think she did."musicnews.com