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THE CANCER ISSUE

A silent, stealth killer of women

Ovarian cancer is usually found after it has spread. The goal: a test to catch it early, in time for a cure.

October 20, 2008|Susan Brink | Times Staff Writer

Like any grandparent helping a daughter with a new baby and two active toddlers, Barbara Shellow was busy: changing diapers, giving baths, reading stories and playing games. The routine had her huffing and puffing, out of sorts, tired, losing weight.

But the Bel-Air grandmother didn't give much thought to those symptoms 11 years ago. It was Idaho, in winter. "I blamed it on the altitude, the weather, and running around after three little kids," she says.

Like the majority of women who are eventually diagnosed with ovarian cancer, Shellow's symptoms -- fatigue, bloating, stomach upset, changes in bowel habits, loss of appetite -- were as vague as they are common. She chalked them up to life and, like so many women with the disease, waited too long to go to the doctor.

The very banality of this cancer's early symptoms is what makes it so deadly -- that and the fact that there is no early-screening tool, such as a mammogram for breast cancer or a Pap smear test for cervical cancer, to either reassure women that they're healthy or find cells at early and highly curable stages.

As a result, the majority of women diagnosed with ovarian cancer are already in the late stages, 3 or 4, meaning it has already escaped the ovaries.

"Ovarian cancer is our albatross in ob-gyn oncology," says Dr. Beth Karlan, director of the Women's Cancer Research Institute at Cedars-Sinai Medical Center. But with care, some patients will see more years than they dreamed possible when they first heard the dreaded diagnosis.

"Ten additional years is nothing to sneeze at," Karlan says. "And the beauty of it is seeing how some of these women live each and every day of those added years."

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Silent invader

Ovarian cancer's stealthy onset makes it far more worrisome than its prevalence would indicate. There are 22,000 cases diagnosed each year, and a woman's lifetime risk of ovarian cancer is about 1 in 70. That compares with a 1 in 8 lifetime risk of breast cancer. "It's an infrequent disease," says Dr. Carmel J. Cohen, professor of gynecology at the Mount Sinai School of Medicine and co-chairman of the Ovarian Cancer Research Fund.

But compared with breast cancer, the risk of dying from ovarian cancer hasn't improved much in the last 30 years. From the late 1970s to today, the five-year survival rate for breast cancer rose from 75% to 89%. In that same time, five-year survival rates for ovarian cancer went from 38% to 46% today.

In just the last decade, the ovarian cancer mortality rate has stayed the same, even as breast cancer mortality has dropped by about 2% a year.

The elusive goal for ovarian cancer is a simple test, like the Pap test for cervical cancer, that would find the disease early enough for it to be cured. Cervical cancer has known precursors: abnormal cells that show up years before cancer develops. And the annual Pap can find them. It's not perfect, but if a woman has a Pap every year, even if the precursors are missed one year they'll almost certainly show up the next -- long before the eight to 10 years it takes for the cells to develop into cervical cancer.

If ovarian cancer has similar precursors, they are hidden in the ovaries, and medicine hasn't learned how to get at them for routine screening. So women and their doctors remain unaware of the disease as it develops into Stage 1 cancer and beyond.

"In the first stage, ovarian cancer can be cured 95% of the time," says Dr. Robert Morgan, oncologist and researcher at the City of Hope National Medical Center. But fewer than 20% of women find it that early.

So far, the only test for ovarian cancer is the CA125 test, a blood test that measures a protein found in greater concentration in ovarian cancer cells than in other cells. But as a screening tool, the test is not specific enough. About 20% of women with ovarian cancer don't have an elevated CA125 count at the time of diagnosis. And of those who do have a high count, only about 3% have ovarian cancer.

Combined with an ultrasound examination of the ovaries, the test can be useful for women at high risk for ovarian cancer: those with a family history of the disease; who carry the BRCA1 or BRCA2 gene; or who have had breast cancer. But even then, the test provides only short-term reassurance. And so use of the CA125 test is limited largely to monitoring women who know they have ovarian cancer to see how well chemotherapy is controlling the spread of the disease.

There have been disappointments in the search for a better test. A few years ago, a test called OvaCheck offered great promise, only to fall flat as experts questioned its ability to test women outside a laboratory setting.

The same hope and fear is percolating over a new test, OvaSure, which measures CA125 and five other proteins in the blood that are produced by a tumor or in reaction to one.

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