Breast cancer mystery: Seeking answers in Marin

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November 10, 2002

By GUY KOVNER THE PRESS DEMOCRAT

Marin County's skyrocketing breast cancer rate, possibly the highest in the nation, has health officials and community activists scrambling for answers that experts say may apply to other affluent populations, including Sonoma County's.

With millions of dollars in research on the line and the attention of the nation focused on Northern California, unraveling the cancer mystery in Marin has become a top priority of politicians, health officials and thousands of residents.

Invasive breast cancer cases in Marin increased by 60 percent in the 1990s, while the Sonoma County, Bay Area, state and national rates remained unchanged. The decadelong upswing, capped by a 20 percent spike between 1998 and 1999, has experts baffled.

"We have no idea," said Rochelle Ereman, the Marin County Department of Health and Human Services epidemiologist hired to search for the reasons. "Everybody is asking, 'What is it?'"

The concern that scientists can't explain the increase culminated Saturday with a countywide door-to-door canvass by about 2,000 volunteers asking Marin residents for help and information.

It's a grass-roots effort of unprecedented scope, said Judi Shils of Ross, founder of the Marin Cancer Project, the organization behind the canvass.

Women from Petaluma and the city of Sonoma who formerly lived in Marin were among the volunteers. "This is coming from a place of unbelievable passion," Shils said.

For Sarah Comerford, a breast cancer survivor from Marinwood and a canvass neighborhood leader, it was personal.

Two years after her diagnosis and subsequent treatment, she shows no recurrence of breast cancer -- but wants answers for her daughter's sake.

"It terrifies me that she would have to go through something like that," she said.

Cynthia Murray, Marin County Board of Supervisors president, said no other nonpolitical issue has generated so much activism.

Murray said she, too, takes it personally as a woman in the 45-64 age group, where the breast cancer rate increase was concentrated.

Marin's rate of 230 breast cancers per 100,000 people in 1999 was far above the national average of about 140. By comparison, Sonoma County's rate was 127 cases per 100,000 population in 1999, down 21 percent from the decade's peak rate of 161 in 1994.

Because Marin, a compact suburban county of 250,000, is a virtual island of affluence, the county's spiking breast cancer rate is often attributed to high-end demographics. The county has a median per-capita income of almost $58,000, tops in California and about 200 percent higher than the national average.

Sonoma County's median income is $32,500.

High socioeconomic status is considered a "risk factor" for breast cancer, partly due to the tendency of affluent, educated women to delay child-bearing and have smaller families.

With more uninterrupted ovulation, a woman's breasts are increasingly exposed to sex hormones, which are believed to promote cancer growth.

Larry Meredith, Marin Health and Human Services director, said the answers lie in a "complex interaction" of genetic, biological and personal factors, which he likens to a Rubik's Cube.

Risk for men

Men as well as women are at risk in Marin, which has the state's highest rate of prostate cancer. An exclusively male disease, prostate cancer strikes and kills almost as many Californians as breast cancer, which occurs primarily in women.

The political push for answers about prostate cancer is just beginning, "but it's years behind breast cancer," Meredith said. One reason for the lag, he said, is that men are typically less health-conscious than women.

The cancer concentration has led some Marinites to wonder if something in the air, water or their storied lifestyle is responsible.

"The theories are abundant and dramatic," said Christine Jager of San Anselmo, the cancer project's volunteer coordinator.

Plastic water bottles, sudden oak death, cellular phone towers, dirty air blown from the East Bay and ocean-dumped toxins are among the suspected culprits, but some activists agree with the experts that it is a modern medical mystery.

The county, with help from California Sens. Dianne Feinstein and Barbara Boxer and Reps. Nancy Pelosi and Lynn Woolsey, is seeking $1 million in federal funds for a host of research projects.

Boxer, a Greenbrae resident, is a former Marin County supervisor.

Waiting for funding

Four federal agencies have pledged to help explore Marin's breast cancer rate, but none has committed any money, Meredith said.

Marin gained the tag of "breast cancer capital of the world" a decade ago, after researchers found an elevated rate of the disease there -- and in other geographic areas with comparable levels of income and education.

A study released early this year by the Northern California Cancer Center attributed Marin's high disease rate to "a higher concentration of women with a higher breast cancer profile."

The study, completed by the private, nonprofit research institute based in Union City, was limited to white, non-Hispanic women because there were fewer than 10 cases of breast cancer a year among Marin's black, Hispanic and Asian/Pacific Islander women.

"We're seeing something terrible there, but we're seeing it because it's a fairly homogenous county," said Tina Clarke, an epidemiologist and lead author of the study.

Marin's median home price was $530,000 in 2000, compared with $315,000 in Sonoma County.

More than half of Marin adults have a college degree; in Sonoma County, 29 percent do.

Breast cancer may be soaring in other affluent areas, such as Beverly Hills, Palo Alto and Atherton, but the census data for cities and towns -- anything smaller than a county -- won't be available to make that assessment until next year, Clarke said.

'Canaries'

The women of Marin County may prove to be the "canaries in a gold mine," signaling a threat to affluent, educated women everywhere, her report states.

As the income and education level of Sonoma County women continue to rise, it becomes a "prime target," Clarke said.

If Sonoma County's wealthier, educated women already were experiencing high breast cancer rates, the trend would be "camouflaged" by a more diverse population, Meredith said.

Mary Maddux-Gonzalez, Sonoma County's public health officer, said she is watching Marin County "with great interest" but said it is too early to know if breast cancer may be epidemic among some segments of Sonoma County's population.

"I don't think we can come to that conclusion yet," she said.

Maddux-Gonzalez acknowledged that studies have established an alignment between affluence and increased risk of breast cancer.

Like other health experts, she advises women to breast-feed their babies, drink alcohol in moderation and, above all, get regular screening to defend themselves against breast cancer.

Breast cancer is the most common cancer among women, accounting for about 192,000 new cases and 40,000 deaths a year in the United States, according to the American Cancer Society.

Clarke said she discounted environmental toxins, such as fertilizer and pesticides, as a cause of the Marin cancers. Some studies suggest a connection, but Clarke said the evidence is "shaky" at best.

But Meredith, noting that 85,000 chemicals are commercially available in the United States, said no potential factors can be ignored.

"We are currently marinating in this chemically based environment without knowing the effects," he said.

Among the Marin studies already under way are an assessment of traditional breast cancer risk factors, as well as inventories of possible environmental and even household toxins.

Alcohol factor

Ereman, the Marin epidemiologist, said alcohol -- a recognized breast cancer risk factor -- merits a closer look.

A recent study found that 76 percent of Marin women had at least one drink in the preceding month, compared with 53 percent statewide and 46 percent nationally.

Clark, a wine drinker, recommended that women consume no more than one drink of alcohol a day.

Experts agree there is a big gap -- Ereman called it "a black hole" -- in what science knows about breast cancer.

About half the breast cancer cases nationwide cannot be explained by established risk factors, such as income, child-bearing pattern and family history, the cancer center's study states.

Investigation of Marin's cancers may shed light, as it did 30 years ago.

In the 1970s, research prompted by Marin's soaring rate of uterine cancer led to a link between that disease and estrogen-only therapy then used by postmenopausal women.

The result was development of combined estrogen-progestin therapy to treat symptoms like hot flashes and mood swings and to prevent osteoporosis.

As research comes full circle, the combined therapy is now a suspected factor in breast cancer.

Research money

Meredith said Marin will push for grants, from Marin's own Buck Foundation and personal philanthropy, as well as the government, to help fund millions of dollars worth of research.

With a slumping economy and the threat of war, it's a tough time to be scratching for money, Meredith said.

"On the other hand, we think we have a compelling situation here. We think Marin County can be used as a laboratory to answer some of the questions."

-- Anonymous, November 10, 2002


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