It takes a special event to bring all three weeknight broadcast news anchors together.

As in its inaugural edition two years ago, “Stand Up to Cancer” remains such an occasion. The hour-long, celebrity-filled program combining information on the disease with appeals for donations to fund research will involve ABC’s Diane Sawyer, CBS’ Katie Couric and NBC’s Brian Williams when their networks air it simultaneously – along with many other TV outlets such as Fox and VH1 – at 8 p.m. Friday.

Among personalities slated to take part are Michael C. Hall of Showtime’s “Dexter,” who was treated for Hodgkin’s lymphoma earlier this year, and Laura Linney of the same network’s “The Big C,” in which she plays a cancer patient. Christina Applegate, Lance Armstrong, Fran Drescher, Elizabeth Edwards and Maura Tierney are others on the roster who have had firsthand experiences with cancer.

With the first telecast, the Stand Up to Cancer movement raised more than $100 million. From the start, Couric has been at the forefront of the Entertainment Industry Foundation-backed initiative, largely in memory of two of her loved ones: her attorney husband, Jay Monahan, who died of colon cancer, and her sister Emily Couric, the Virginia state senator claimed by pancreatic cancer.

“If you had any concept of what goes into putting together an event like this, you’d be absolutely astounded that we could do it even every two years,” Couric says. “It requires so much work ... not only producing the show but also encouraging various networks and cable outlets to carry it again. There’s also getting corporate sponsors, distributing the money we’ve raised so far and keeping tabs on the progress that’s been made. I’m thrilled that we’re able to do this again.

“The American Association for Cancer Research had to be very deliberate and methodical about who would receive those grants, and which teams would be working together,” Couric adds, “so a lot of moving pieces had to be figured out before we could proceed to raise and give money to these dream teams of innovative researchers. The big show is just one element of our effort.”

A website is maintained continually at both www.standup2cancer.org and www.su2c.org.)

Williams also knows the impact of cancer only too well: He lost his mother to non-Hodgkin’s lymphoma, and his sister to breast cancer after what he terms “a long, brave fight. I’m not at all the catalyst for doing this, but I went back to (the special’s organizers) six months ago and asked, ‘Are we ever going to do this again?’ However much the traditional three broadcast networks have the power to focus people’s attention and bring viewers together on a single night, we sure hope to do that.”

For Sawyer, this year’s “Stand Up to Cancer” is her first, since her evening anchor predecessor Charles Gibson represented ABC’s news division on the 2008 special (as did breast cancer survivor Robin Roberts of “Good Morning America,” who will participate again).

“We all love the idea of linking arms across networks,” Sawyer says. “There are some things that break down all walls, divides and distinctions, and we do this together because it can be done, and it does work.

“Personally, Katie and I have talked about our lives over the years, but this is something I’m getting to know. All three anchors came on ‘Good Morning America’ about this when I was there, and the group of us sat together and talked about what they were going to do. It’s an evening that has joy and hope, and I hope everybody knows that.”