DETROIT -- The cancer doctor who subjected more than 500 patients to unnecessary treatments got a small show of support on Thursday.

Two former patients asked a federal judge to be lenient Friday when he sentences Dr. Farid Fata. Prosecutors have asked for a 175-year sentence.

In court today awaiting his sentence, Dr. Farid Fata sat a few feet away from Monica Flagg, his former patient, whose case is one of many now sending him to the penitentiary.

Fata told Flagg she had bone marrow cancer when she didn't. He put her on chemo he said she would need for the rest of her life.

Dr. Farid Fata, a Detroit-area cancer physician pleaded guilty to giving fraudulent medical treatments to more than 550 patients. CBS News

"I have never heard of something like this in my life," said Dr. Soe Maunglay, a former employee of Fata's.

Maunglay, a native of Burma, was working for Fata as an oncologist in 2013 when he met Monica Flagg. He read her medical chart and shook his head.

"There was nothing really to support he patient had active cancer," he said.

He asked the patient "in a very sarcastic way" who diagnosed her disease because he knew who had. He was enraged.

Monica Flagg CBS News

Maunglay had misgivings about his boss before, such as a disorganized assembly line of patients and a reckless use of chemo. Monica Flagg's case was just too much.

Days after Maunglay reported it to a superior Fata was under arrest. More than 500 patients had been victimized with chemotherapy they didn't need or expensive doses far too extreme for them to handle.

Maunglay said he felt very satisfied when Fata was arrested knowing that at least it had stopped.

"I think he's guilty of the most cruel thing a human being can do to another human being," he said. "I'm trying to be a very forgiving person but that day is not today yet."

Prosecutors say it was all about the money. Fata, 50, pleaded guilty last fall to fraud, money laundering and conspiracy. He will be sentenced Friday.