BOSTON -- A female postal worker narrowly escaped an attack by a knife-wielding man in Dorchester, police said.

Officers said Bertha White, a fill-in postal carrier, was delivering mail on her route on Mount Bowdoin Terrace about 2:30 p.m. Wednesday when a man with a knife jumped out, pushed her to the ground and demanded cash.

White, who suffered wounds to her hands and back, told NewsCenter 5's Kelley Tuthill that she believes heavy winter clothing saved her life.

The attacker pinned her to the ground, but she was able to spray him with pepper spray before he fled.

White was able to give police a description of the man, and said he was wearing a black hooded sweatshirt and cap, black boots and had a diamond earring in his right ear.

White, who is a breast cancer survivor, said she fought her attacker the same way she fought cancer.

Residents put up wanted posters in the neighborhood and there is a $50,000 reward for information leading to the man's arrest.

"I was just hoping she was OK. She was in the office this morning, talking to the other carriers and she was saying she was glad it wasn't me," said Jerry Coughlin, who is the regular mail carrier for the route.

White said she loves her job, but was traumatized by the attack and needs some time to think before returning to work.