Kellie Pickler
Season-5 Earnings-$1.8 million REUTERS

Country music star Kellie Pickler buzzed off her blonde locks as a show of support for her best friend from childhood, who is battling breast cancer.

Pickler, 26, teased her Twitter followers about shaving off her blonde hair in a cryptic tweet sent out Tuesday night.

"It's been a great life-changing day," the former "American Idol" singer tweeted. She followed up the post urging her more than 585,000 followers to tune in to "Good Morning America."

"Be sure to watch "Good Morning America" tomorrow morning (Sept 5th). You won't want to miss this!!! ;)," Pickler said.

The country star gave the morning show exclusive video of her buzzing off her blonde hair, which you can view here.

Pickler's made the change in her hairstyle to show her support to childhood friend Summer Holt Miller, 35, who was diagnosed with breast cancer and was set to start chemotherapy treatment Wednesday. Both women shaved off their hair at the same time.

The country star said she hoped her act of solidarity would spur her fans to get mammograms so they could detect breast cancer early.

"Cancer does not discriminate," Pickler told ABC News in a statement.

Miller noted that she is only 35 and has breast cancer despite doctors' recommendations that women first start getting mammograms at 40.

"If this compels even one person to change their mentality toward waiting until the age of 40 for their mammogram, then it will be worth it," she told ABC News.

Miller is documenting her breast cancer journey on a journal hosted by caringbridge.org. She last posted Aug. 29 under the headline, "Just a Nightmare?"

"For the first time since I was diagnosed, I woke up this morning and my first thought was... 'Was this all a very bad dream?' I'm not sure as to why it happened this morning but as soon as I tried to roll over and look at the clock, pain from yesterday's expansion appointment with [my doctor] hit me like a Mack truck and I was quickly reminded that this nightmare was anything but a very bad dream," she wrote.

Miller added that she has faith that she will beat breast cancer.

She continued in the post, "However, my Jesus quickly whispered to me, 'But you're a survivor!' and my husband was soon beside me offering my pain medicine and a good morning kiss. I'm so blessed!"

Pickler's friend also explained why she shaved off her hair.

"I'm going ahead and shaving my head the Tuesday before because I was told that it was mentally much easier to do it this way than to wake up with hair on my pillow," she wrote. "I'm really not that apprehensive about shaving my head. It is hair and it will grow back. However, I am secretly hoping that it grows back like my friend Tonia Icenhour's did... thick and curly. :)"

Miller's journal has seen a surge in traffic since Pickler highlighted her best childhood friend's diagnosis. The blog has been visited by more than 17,000 people as of Wednesday afternoon.