The Oscar-winning actor, who is starring in a reboot of the legal drama Matlock, had the procedure after she was diagnosed in 2012.
Speaking on the MeSsy with Christina Applegate & Jamie-Lynn Sigler podcast, the 76-year-old said: "This is really weird maybe... but I had really heavy breasts. They were like 10 pounds when they removed them. Really big breasts. And I kind of enjoy not having breasts. It's strange."
She added: "There was a friend of mine who was concerned when I decided not to have reconstruction, because at the age I was, I thought, I really don't wanna go through that, and I just didn't wanna go through it, you know? I wasn't in a relationship. I was older, and I didn't think that I would be in a relationship. And so it was kind of like, 'Why do I have to?'"
Bates praised the wardrobe department on her new TV show for special adaptations made to her clothing.
"At Matlock, they devised a really cool - it's Spanx-ish - kind of camisole, very thin straps... and they put little, you know, falsie cups in it," she said. "And they 're so comfortable, and they give me a nice shape. And that's it! I mean, I feel so good when I go out like that."
Bates said that, before this wardrobe development, she had struggled. "For a while, I just didn't go out with any prophylactics... or at all. Or I went out with them [and] they're hot and heavy, and they made me unhappy."
The actor, who is best known for her Academy Award-winning performance in the 1990 Stephen King horror Misery, also recently opened up about her recent weight loss.
"There's been a lot of talk that I just was able to do this because of [weight loss medication] Ozempic," she said. "But I have to impress upon people out there that this was hard work for me, especially during the pandemic. It's very hard to say you've had enough."
Bates explained that she lost 80 pounds through changes to her lifestyle and diet, and lost another 20 pounds while taking Ozempic. While the once-weekly injectable medication is prescribed to patients with Type 2 diabetes, which Bates does have, the drug has also risen in popularity for its off-label weight loss side effects, with celebrities from Oprah Winfrey to Sharon Osbourne using the drug.
CBS's Matlock, which will air on Sky Witness in the UK from 26 November, comes nearly four decades after the original 1986 hit starring Andy Griffith.
In the show, Bates plays Madeline "Matty" Matlock, a lawyer who decides to rejoin the workforce, using her age and wit to get a job at an esteemed firm.