California's breast cancer blight

By Maggie Shiels in California

California boasts the world's fifth largest economy, the biggest population in the US and is home to Silicon Valley and the film industry. And you can now add to that glittering list of achievements the title "breast cancer capital of the world".

What we see here in Marin may be a harbinger or warning of what is going on in similar areas in other parts of the country and perhaps the world

Dr Tina Clarke, epidemiologist

A report just published by the Northern California Cancer Center says the San Francisco Bay Area as a whole has the highest rate of the disease for anywhere on the globe.

More alarming is the fact that there has been a 20% jump in breast cancer cases in one year among white women in Marin County, situated just north of the city of San Francisco.

The numbers, compiled from 1999 data, represent the largest recorded annual jump in the breast cancer rate ever in Marin, which already topped the league for any county in the Golden State.

Staggering stats

The study focuses on white women because there are less than 10 African American, Hispanic or Asian American women diagnosed each year and rates and trends are difficult to analyse for these groups.

Fern Ornstein: This is a wake-up call for everybody

Dr Tina Clarke, an epidemiologist at the centre, told BBC News Online: "Between 1991 and 1999, rates have increased about 60% in Marin, as compared with increases of less than 5% in other urban parts of the state.

"Breast cancer rates for white women in Marin are now 28% higher than rates in other counties in the San Francisco Bay Area and 38% higher than rates in other urban parts of California."

The research shows that the increase in 1999 was mostly confined to women aged 45-64. In Marin, these rates are 58% higher than in other parts of the Bay Area and 72% higher than in other urban parts of California.

At a loss

Fern Ornstein is a breast cancer survivor who was diagnosed with the disease in 1996. She says the dramatic increase is depressing but should be used as a launch pad to heighten overall awareness.

Sitting poring over local newspaper headlines from the report, Ms Ornstein said: "I hope this is a wake-up call to individual women and the community at large to try to understand these rates and what they mean.

"We need to try to better understand what this epidemic is all about. We need to be more aware, more informed and more vigilant about breast cancer health."

Most experts admit to being at a loss when trying to explain why one of the wealthiest counties in the whole of California is prone to such a rise in the disease.

Wider warning

Marin is famous for its exercise-conscious lifestyle and prevalence of organic food stores and farmers markets, but Dr Clarke said there were some clues to hint at what set Marin apart.

Janice Barlow: There must be environmental factors

For starters, she underlined the fact that breast cancer was more prevalent in older, wealthier white women who either did not have children or put it off until they were in their 30s and 40s. And Dr Clarke also pointed to Marin's female population being older; average house prices of around $700,000 meant few young women with families could afford to live in the county.

For Dr Clarke, the current picture should concern everyone. "What we see here in Marin may be a harbinger or warning of what is going on in similar areas in other parts of the country and perhaps the world."

Dr Margaret Wrensch is an epidemiologist from the University of California at San Francisco, who says it is hard to know what to make of the rise in cases without more research.

"The biggest question for me is why is it that breast cancer is associated with high socio-economic status? This is one of the major killers of women in the US and probably elsewhere," she said.

Death rate

"We have observed this situation throughout the world for many decades but we still don't have a good handle on what it is about this group that results in a high incidence of the disease."

At Marin Breast Cancer Watch there is a belief that environmental links may play a part. Janice Barlow is the group's executive director and is preparing a report into the subject for a Select Committee hearing on Cancer Detection, Prevention and Research.

"We know well the connection between a high socio-economic level - and that women in Marin often fall into that category. So people dismiss it because Marin women have children later and we understand that is a risk factor. But that only explains 50% of the cases of cancer and we have women who come here who don't have any of those risk factors.

"So, it's frustrating to see the incidence continue to rise and that makes us think there are other factors involved and we should look at the links between the environment and breast cancer."

The report also reveals that the death rate In Marin is also 25% higher than the rest of the Bay Area and California.