Cathy Hainer, 38, a USA Today features reporter who was by turns sternly strait-laced, movingly personal and grimly humorous in a series the paper ran of her ultimately fatal fight with breast cancer, died Dec. 14 at the Hospice of Northern Virginia. She lived in Arlington.

Since her diagnosis of Stage 4 cancer--the most severe level--in January 1998, Ms. Hainer wrote 12 installments in diary form that were printed occasionally until Dec. 6, 1999. The account brought her struggle to public attention and acclaim among the newspaper's 2.2 million readers.

As they unfolded, Ms. Hainer's stories spotlighted chemotherapy and hair loss, drug treatments, surgery, engagement to her boyfriend, a daily dreading of bodily deterioration and occasional calmness of mind and spirit. She also was haunted by her own mother's death of the disease in 1995.

"As a writer, Cathy really found her voice during this two-year process," said Susan Weiss, managing editor for the paper's Life section. " . . . I think what this experience brought out in her was an ability to really question and look for answers and not necessarily always to find them but to document the process of searching."

In her first story, Ms. Hainer visited a doctor for a routine examination and wound up having surgery immediately because of a lump found in her breast. She later saw suspended in a water-filled specimen jar cancerous tissue resembling "three red-tipped wiggly worms." She looked at her boyfriend, saying the doctor is "crazy . . . I'm 36 and in love. How could I possibly have breast cancer?"

Ms. Hainer prayed often at a synagogue, finding some comfort. "Maybe that man was dealing with the death of a parent, or that couple was aching over the illness of a child. We're all fighting some battle. I could feel my own anger dissolve. I didn't feel so singled out."

And she found humorous relief in the mundane. "I returned to my apartment on Monday morning to find that a crack in my toilet had leaked water on the bathroom floor," she wrote. "A plumber came out and had to replace the whole commode, to the tune of $500. People with cancer shouldn't have to pay plumbers' bills."

The American Cancer Society estimates that breast cancer was diagnosed in 175,000 women this year and 43,300 died of the illness.

Ms. Hainer was a Virginia Beach native and graduated in 1984 from the College of William and Mary. She was a writer at New York magazine from 1984 to 1990 before joining USA Today as a news assistant and researcher. At the time of her death, her beat included general trends and the publishing industry.

Ms. Hainer instigated the cancer series, initially hoping to chronicle beating the illness, Weiss said. When Ms. Hainer discovered she would not live long, she made a commitment to follow through on the story.

Weiss said that as her illness progressed, Ms. Hainer "tried with all her might to come to the newsroom. Only when she really became incapacitated [in late summer] did she stop. Then she worked from home on a laptop."

Ms. Hainer's last diary entry included a matter-of-fact acceptance of the disease and what it had done to her. But she found the workaday worries of life still intruded on her thoughts.

"Should a dying woman buy a new nightgown? I truly didn't know," she wrote. "Does she floss her teeth? Pay her bills on time? Renew her driver's license? In other words, how much of an effort do I make to rejoin life? How much do I accept the inevitable?"

Last year, USA Today bestowed on Ms. Hainer an award for outstanding achievement for a news staff member. On Nov. 22, the paper renamed its in-house awards the Hainer Awards.

Survivors include her father and stepmother, Stan and Shirley Hainer of Virginia Beach; and three brothers.