Decades after she first lit up the screen with her intoxicating sex appeal, Italian film legend Sophia Loren makes her comeback as an Auschwitz survivor and former prostitute in The Life Ahead.

In her first film role in 10 years, the 86-year-old actress plays Madame Rosa, an elderly woman who makes a living looking after the children of prostitutes.

The film is based on La Vie Devant Soi, a book by French-Lithuanian writer Romain Gary, which won the country’s most prestigious literary prize, the Goncourt, in 1975. The movie was a labour of love for Loren’s son, Edoardo Ponti, who co-wrote it as well as directing it.

“When Edoardo showed me the script, I immediately knew this was the story I was waiting for,” the actress has said. “It’s wonderful, I’ve been waiting for this sort of role for a very long time.”

Madame Rosa, old, battered by life, her body in tatters, doesn’t at first look like a good fit for the former screen siren but it’s easy to forget that Loren made her name (and won an Oscar, the first for a foreign language film role) in the gritty Second World War drama Two Women. She also starred in some excellent Italian neo-realistic movies before she reached Hollywood and international stardom.

Loren throws herself into the role of Madame Rosa with no holds barred, her face heavily lined, hair gray and unkempt. She shows her soldiering on, up and down the six flights of stairs to her flat, panting, scared that she might collapse. Her past still haunts her: she still panics when she hears unexpected noises – are the Fascists coming to get her, again? – and when terror overwhelms her, she takes shelter in the basement, in a room no-one knows about.

Loren has revealed that to create Madame Rosa, she drew on the memories of her mother, channeling her strength and her fragility, and her overwhelming love for her children.

Madame Rosa’s gruff sort of love — for her charges, for the ethnically and sexually diverse cast of characters that surround her — finds an outlet in Momo, a 12-year-old Muslim street urchin who comes into her tired life after trying to rob her. After a few initial clashes, the two end up looking after each other.

The book was first adapted for the screen as Madame Rosa in 1977 by Israeli director Moshe Mizrahi with French actress Simone Signoret in the title role, winning an Oscar for best foreign language film.

But while in the earlier film the story was told from the point of view of Madame Rosa, in Ponti’s movie it is seen through Momo’s eyes, as in the book. Ponti has, however, changed the setting from the Belleville suburb of Paris to the Italian port town of Bari, which because of its location at the southern end of Italy has seen a huge influx of migrants from the African continent. So Momo, Algerian in the book, has become Senegalese in the movie.

But like the book, the film tells a story of tolerance, acceptance, fear of loneliness and the universal need for love, which, Loren says, are more necessary than ever.

The Life Ahead is on Netflix from 13 November