SHE'S RUNNING FOR TWO : MARATHONER, AND SISTER, HAUNTED BY CANCER.

Byline: Michael Rosenthal Daily News Staff Writer

Twin sisters Kris Murphy and Kathe Flinders, 44, have been in a race against cancer for some time.

Specifically, they've had to contend with a mutated gene, BRCA1, that runs in the family. And kills. Women with it have an 85 percent chance of developing breast cancer and a 60 percent chance of contracting ovarian cancer.

One by one, their mother, grandmother, aunt and great aunt - all from their mother's side - developed breast cancer. None survived.

Last year, it was Flinders' turn. In April, she was diagnosed with ovarian cancer. In her case, there's good news: After 10 months of chemotherapy, the Sherman Oaks resident is in remission.

Murphy, an avid runner who recently moved with her family from the L.A. area to Eleva, Wis., plans to run the Los Angeles Marathon on Sunday. She has dedicated the race to her sister.

Two days later, she's scheduled to have a double mastectomy and reconstructive surgery to prevent breast cancer. Soon afterward, Flinders will do the same.

``I don't know why I don't have cancer,'' Murphy said by telephone from Eleva. ``I just keep running to run away from it. I'm not going to let it catch me.

``I'm not going to stop long enough for it to get me.''

Flinders' months of chemotherapy ``were as horrible as you can imagine.''

``It almost killed me,'' she said.

It also was effective. Today, with the chemotherapy behind her, she looks well and her spirits are relatively high. She has come a long way since April.

``It was an `I'm-going-to-die' kind of thing,'' said Flinders, a divorced mother of three. ``I thought I was going to die within a year. It was so scary. I remember crying, crying and crying.

``Then I met people who've survived long-term. That made me much more optimistic.''

When Murphy heard the news of Flinders' diagnosis, she flew to Los Angeles immediately from a vacation in Hawaii to be with her.

The two are so close, Murphy said, her sister is like an ``appendage, a part of me.'' Since Murphy moved to Wisconsin, they talk on the phone three or four times a day.

``It was like being kicked in the stomach,'' said Murphy, referring to the moment she heard the news. ``It took my breath away. You go through life thinking nothing will change, you take things for granted.

``They say twins are symbiotic. I really felt sick. At times I felt like I couldn't breathe just watching her.''

With the frightening family history, Murphy has taken every proactive measure she can. Last summer, she, like her sister before her, had a total abdominal hysterectomy and an oophorectomy.

And the decision to have the double mastectomy wasn't difficult. All she had to do was consider the overwhelming odds working against her - the 85 percent chance she will get breast cancer.

Doctors cannot eliminate the possibility of developing breast cancer because some tissue is always left behind. However, the odds are reduced by 90 percent.

That's good enough for both Murphy and Flinders.

``People say, `Why cut off your body parts?' '' Murphy said. ``My attitude is a reactionary one. I'm paranoid. There's something I can do to reduce the risk so I'm going to do it.

``Others say, `Why don't you just have it checked regularly?' I say I don't want to deal with that. People are human, they make mistakes.''

On Sunday, Murphy will be running for two, although in the last quarter mile or so she'll have company. Flinders, who just this week was able to ride her horse for the first time in six months, will finish the race with her sister.

Murphy, who has been running for more than 20 years, will be taking part in her fourth 26.2-mile race. This one will be different.

``She's been so obsessive about this marathon,'' Flinders said. ``In her mind, she's doing it for me. I say, `You don't need to do this.' She says, `Yes, I do.'

THE CITY OF LOS ANGELES MARATHON

When: Sunday, 8:45 a.m.

Start: Figueroa Street at Sixth Street.

Finish: Flower Street at Fifth Street.

TV/Radio: Channel 13; KACD/KBCD (103.1 FM).

CAPTION(S):

Photo, Box

Photo: (color) ``I'm not going to stop long enough for it to get me.''

- Kris Murphy, left

on running to stay alive. She and her twin sister, Kathe Flinders, have a mutated gene that causes cancer. Murphy will dedicate her participation in Sunday's Los Angeles Marathon to Flinders.

Box: THE CITY OF LOS ANGELES MARATHON (see text)