Los Angeles, Dec 30 (IANS): Actress Felicity Jones spent time with cancer patients who were going through chemotherapy, to understand their tryst with the disease. She did this in preparation for her role in the upcoming film "A Monster Calls".

In the JA Bayona directorial movie, Jones will be essaying a young parent diagnosed with a terminal illness. To better portray the character, the actress opted to visit oncologists, read a statement issued on behalf of the makers of the film.

"It was very important to all of us to get it right, to tell this story truthfully and with love and respect, especially for those who will see the movie and who have been through this experience with loved ones," Jones said.

" I wanted to get the medical perspective, to know exactly which medications someone would be taking and just how people try and fight the disease," Jones added.

"What was incredible was speaking to people who are going through chemotherapy. I met women who were very frank about their experiences and who would take me through the daily rituals of how you cope with something like this. After I had absorbed everything I could, I coordinated efforts with our movie's incredible crew to chart Lizzie's decline," she added.

Bald caps and prosthetics make-up were applied to dramatize the physical effects of the illness taking hold.

Jones also lost weight to show how the cancer was affecting the body.

"I wanted to convey how her breathing changes, and for us to see her body gradually getting weaker and altering. In reading the script, I identified four specific changes in her physicality, and it became all about trying to show those shifts as subtly and as truthfully as possible," the "Rogue One: A Star Wars Story" actress said.

"A Monster Calls" is due to release in India on January 6, 2017.