05/19/2010 08:17 am ET | Updated May 25, 2011

Katie Couric, Diane Sawyer, And Brian Williams Join For Stand Up To Cancer (VIDEO)

"Wouldn't it be great," Diane Sawyer said Wednesday morning, "if we could all come on the air and have the same lead story and it says, 'We have done it. We have found something. It is working. The world will be different from now on.'"

Sawyer was referencing the effort -- which she joined this year alongside fellow evening news anchors Katie Couric and Brian Williams -- to support Stand Up To Cancer, which in September will air a commercial-free telecast across all three major networks as well as several cable partners.

Couric and Williams have done this before -- they co-hosted, along with Charlie Gibson, the first Stand Up To Cancer broadcast in 2008 -- but it is Sawyer's first time getting involved with the production.

"I was just with Robin Roberts and she did it two years ago, and she was telling me what I know is true: that there's a real spirit of joy on the stage and on the phones and in the room," Sawyer told the Huffington Post.

All three anchors said that though they are rivals at 6:30 PM, they are friends outside their broadcasts, and they are happy to come together to support Stand Up To Cancer.

"We are motivated by the competition in the newsroom," Williams said. "Diane and Katie are great competitiors but I think that's why it feels so good to come out on that stage as a threesome."

"There are times we have to say to the world that we are one, we have one goal, and we can do this together," Sawyer said. "I love the fact that it arches across all networks -- and on some cable networks as well -- and that we're taking this time to say: if we all link arms, this can be done."

In 2008, Stand Up To Cancer raised $100 million, and the organization has already committed $85 million to fund "Dream Teams" of cancer researchers from various institutions, who collaborate on researching a cure for cancer.

Couric compared the three rival anchors coming together to this collaborative research model.

"I think it's the microcosmic example of what we're trying to achieve in science, the fact that we're there together and talking about an issue we all care deeply about," she said. "It's very symbolic...the scientists are very excited about the new research model of collaboration and sharing resources. All these brains pooled together can hopefully come up with better answers. One of the themes in cancer research is that the research itself is not so organ-specific. What they're finding increasingly is certain approaches are applicable to all sorts of cancers. And so I think it only makes sense to keep people collaborating."

All three anchors appeared on their respective network morning shows Wednesday to announce the effort, and they filmed promotional videos last week as well. In that video, seen below, they each explain who they're Standing Up To Cancer on behalf of: for Couric, it is her husband Jay, who died of colon cancer, and her sister Emily, who died of pancreatic cancer; for Williams, it is his mother, who died 18 years ago of non-Hodgkins lymphoma, and his sister, who died four years ago after battling breast cancer for six years; for Sawyer, it is the overnight editor at "Good Morning America," James Bogdanoff, who died in 2008 from esophageal cancer.

Williams said that he appreciates the unique approach to fighting a problem that everyone has experienced in one way or another.

"I think people find this really pleasing," he said. "People like the aggression of even the name of it. Go ahead, try it, we're going to show you that you, cancer, have an enemy in the three of us. I don't know anyone who can't tell you a story of what it's done to their friends and family. I dont know anyone who hasnt been at war with cancer. So I just think it's a very, very creative new way of looking at it and going at it."

Couric, who has been an outspoken advocate for cancer research and prevention, said that the disease takes too many people far too early, including her husband and sister.

"My family has been very hard hit by this disease," she said. "Emily had so much to offer. She was running for Lieutenant Governor of Virginia with Mark Warner and had to suspend her campaign, and many people said she would've been the first female governor of Virginia. I was so proud of her and even prouder of her courage in the face of this disease."

Couric said that she has established a clinical care center at UVA that is going to be modeled after the Jay Monahan Center at New York Hospital, which offers "compassionate comprehensive care from all aspects of treating the patient, not just the disease.

"That's a real legacy to what my sister meant to the people of Virginia and to all of us," she said. "This disease leaves behind a trail of sadness but all you can do is build on that in anyway you can to try to fight it and to try to help people."

Stand Up To Cancer will air on September 10 at 8PM ET/PT and 7PM CT on ABC, NBC, and CBS. HBO, Discovery Health, E!, MLB Network, The Style Network and other cable partners will air the telecast as well. It will be executive produced, again, by Laura Ziskin, and promises a star-studded line-up that is yet to be announced.