Last month, when his eighth-grade language arts class at Ponce de Leon Middle School started reading the memoir Why I Hated Pink, Adreyan Pena would quietly excuse himself and wait outside in the hall, trying “to think about other stuff.”

What most students in the class didn’t know was that Adreyan’s mother, Miami-Dade police officer Diana Cordova-Pena, was dying of breast cancer.

Diagnosed in 2009, Cordova-Pena, 36, had waged a successful battle against the disease until about a year ago when doctors discovered new cancer cells. Outwardly, she seemed optimistic. But she confided to a few close friends that the additional chemo she was undergoing was merely palliative. It would not save her life, said her close friend, officer Heather Grimes.

So Cordova-Pena began planning her last year.

She made a bucket list of things to do and places to go with Adreyan and six close friends, also officers at the Northwest District where she worked. Three months before the deadline, she filled out forms Adreyan needed to continue in the International Baccalaureate program at Coral Gables Senior High next year. She visited a photo studio to shoot the portrait that would be displayed at her funeral. She plotted the route from her mother’s house to the church. And she made sure she would be laid to rest in her uniform.

And then, as she slipped in and out of consciousness at a hospital just before she died Oct. 15, she told her only child she would not be coming home.

“She was braver than anyone I’ve seen in my life,” Grimes said. “She did everything she could to fill Adreyan’s life. That was the thing that concerned her most.”

In the end, friends and family say, Cordova-Pena died the way she lived: unafraid, happy and with her 13-year-old son foremost in her mind.

Every year, breast cancer kills nearly 40,000 women. One in eight women can expect to be diagnosed with the disease in their lifetimes. In 2012 alone, there will be an estimated 226,870 new cases. All those numbers add up to immeasurable sadness for families, particularly children. The National Institutes of Health reports that little is known about the number of children who lose parents to cancer. But of those diagnosed with cancer every year, the NIH estimates more than 22 percent will be between the ages of 21 and 55, prime years for raising children.

And for kids like Adreyan, grieving a parent’s death can be a complex and confusing time.

“It’s an enormous loss, like a physical amputation,” said Regina Melchor-Beaupre, a pediatric psychologist with Baptist Health and Child Psychology Associates in South Miami, who completed a two-year clinical fellowship at Memorial Sloan-Kettering Cancer Center in New York, focusing on families and cancer.

Children suffer the same grief, despair and sadness as adults, but it may look different, according to the American Cancer Society. They may show sadness briefly, then seemingly return to their old selves and resume normal activities. But it is because they are so unprepared to deal with the magnitude of the loss that they revert to what they know. Some may even appear to be relieved by the death, if the illness was prolonged. But grief can reappear at any time, even years later.

Seeing his mother take such pains to prepare, Melchor-Beaupre explained, coupled with the work his teacher did in class, likely equipped Adreyan better than anything else Cordova-Pena could have done.