If you're a woman living in Orange County, your risk of contracting breast cancer over a normal life span is one in seven--higher than both the state and national averages.
What's increasing the danger here? Hoda Anton-Culver thinks it's the Orange County style of living, and she's heading a federally funded research project to discover the causes.
Anton-Culver, a professor and chief of epidemiology at UC Irvine's medical school, believes the nature of the county's population makes it prone to breast cancer.
The disease's likeliest victims are ironically the ones with the best health care--white, well-educated, professional and white-collar women who typically give birth later in life. The concentration of such women in Orange County makes it an ideal laboratory for the largest breast cancer study of its kind.
With the backing of the National Cancer Institute, Anton-Culver hopes to enlist every patient in Orange County whose breast cancer was diagnosed between March, 1994, and February, 1996--about 3,000. About 500 women with ovarian cancer will be included because researchers believe the diseases are related.
The aim is to record in detail family histories and lifestyles. Because the target is all cases, not a sample, Anton-Culver hopes the results will be the most definitive yet on what in our heritage, environment and way of life is causing so much of this disease.
Tracking Cancer Cases
The seeds of this study were planted in 1984, when the Cancer Surveillance Program of Orange County was created at UCI to catalogue every case of cancer diagnosed locally.
"This was the first of its type in California because, believe it or not, in the past we had to report flu, measles and so forth, but not cancer. It was not reportable by law," Anton-Culver says.
Even today, cancer is not officially reported in most of the nation, forcing the National Cancer Institute to base its nationwide statistics on only 11% of the population.
Following UCI's example, the California Legislature created a statewide cancer register in 1987. It soon became the largest cancer registry in the world and the first backed by a law that requires physicians and hospitals to report all cancer diagnoses.
UCI now manages the cancer registry for Orange, San Diego and Imperial counties and has close communication with other registries in the state. Consequently, Anton-Culver need go no farther than her own department's computers to gather basic information about virtually every cancer case involving an Orange County resident.
The key to the study--and the reason the National Cancer Institute was willing to allocate $2.3 million for it--is this access to an entire county population, not just a small and error-prone sample.
"The success will absolutely be based on the participation of the patients," Anton-Culver says. "It is voluntary; we invite all of the patients to participate. We have a participation rate right now of over 80%, which is very good for a study like this."
When a new breast cancer case is reported, Anton-Culver's researchers write to the patient's physician. "We ask whether they feel there is any reason we should not contact the patient," she says. "It's the patient's right to participate, but we ask whether the study would cause too much anxiety or anything. Or if the patient has died."
The next step is a letter to the patient explaining the study and inviting participation. "We tell them it's totally voluntary and they can participate in all or part of it."
Consent launches a series of detailed questionnaires that investigators help the patient complete.
The first is a 15-page questionnaire on the cancer history of the patient's children, parents, grandparents, brothers, sisters, half-brothers, half-sisters, aunts, uncles, cousins or any other relative, no matter how distant, who contracted cancer. When was it diagnosed? Where? At what age? What kind of cancer was it? Are they alive? When and where did they die?
Filling in the blanks usually requires some calls to relatives, "but it's amazing how much information patients will get in such a relatively short time," Anton-Culver says. "In fact, most of the time patients know if there's been cancer among the relatives."
The information is used to chart the patient's cancer pedigree. Investigators also obtain samples of the patient's blood and tumor in order to study the patient's genes.
"If there are three close relatives who got breast cancer early in life or got ovarian cancer, it's probably hereditary. A case that has no family history of cancer is probably not hereditary," Anton-Culver says. Researchers will compare the two groups, looking for clues to the factors that promote breast cancer.
The comparison has already yielded some preliminary findings: About 9% of breast cancer cases stem from inherited gene defects, and most of these cancers are diagnosed early in life--before the woman is 50.
An eight-page food questionnaire aims to detail the patient's dietary habits over a lifetime. Questions ask not only, for example, whether you take vitamins, but what kind--stress tabs or one-a-day--and in what amounts.
Do you salt your food? Do you skin your chicken? Do you put lemon in your tea? When you eat out, how often do you go for burgers? Chinese food? Mexican food?
Half of the questionnaire is devoted to a list of specific foods and how often and how much are usually eaten.
Last comes a 22-page questionnaire that hopes to find what in the environment triggers breast cancer. This, Anton-Culver says, is probably the most difficult for patients to complete.
Besides asking for birth, medical, ethnic, marriage, racial, educational and religious background, the questionnaire wants to know how often and when you were ever severely sunburned, how many X-rays you've had in your lifetime, when stressful events occurred, such as loss of a job or foreclosure of a mortgage.
Have you had hormone replacement therapy? Do you exercise, smoke, eat pancakes or burritos? Do you take your steaks well done? Do you use a hand-held hair dryer or an electric blanket? Do you work near animals?
"Some people have difficulty, absolutely," Anton-Culver says. "But if you were exposed to something, it will stick in your mind. We will not find anything that's subtle. We never do; nobody can. But for example, if they had multiple X-rays or were exposed to chemicals, something that is outstanding in their memories, those are the things we are looking for.
"I believe the most important factor in breast cancer is gene and environment interaction. If you have a mutation that predisposes you to breast cancer--whether you were born with it or acquired it--what triggers it? You need those two hits in order to get a cancer.
"What we will be able to do is find out whether the second hit, the environmental hit, is mainly something everyone is exposed to or only a few are exposed to. That is going to help you. If you have a strong family history of breast cancer, you will know what other risks to avoid."
Ultimately, Anton-Culver says, the study's findings should help point the way toward controlling or preventing breast cancer.
(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)
DID YOU KNOW
Of all breast tumors biopsied, 80% are benign.
Most breast cancer occurs after age 50.
Bearing children before age 30 apparently reduces breast cancer risk.
Diet and exercise early in life may also reduce risk.
Breast cancer in men is identical to breast cancer in women. (BEGIN TEXT OF INFOBOX / INFOGRAPHIC)
The Impact in Orange County
Breast cancer is the most common cancer among women. In Orange County, women contract the disease at a higher rate than state and national averages.
Breast Cancer's Toll
For every four cases diagnosed there is a death. Estimates for 1995:
UNITED STATES: New cases, 183,400; Deaths,46,240
CALIFORNIA: New cases, 20,230; Deaths, 5,035
ORANGE COUNTY: New cases, 1,745; Deaths, 415
Rates by Ethnicity
Female breast cancer in Orange County, 1991
White: Actual cases- 1,239; Cases per 100,000 population-120.78
Hispanic: Actual cases- 98; Cases per 100,000 population-62.15
Black: Actual cases- 6; Cases per 100,000 population-45.86
Asian/other: Actual cases- 50; Cases per 100,000 population-43.79
Rates by Age
Female breast cancer in Orange County, by age, 1991
Most Common Cancers
Estimated cases in Orange County, 1996
Rates by County
A sampling of breast cancer diagnoses per 100,000 women by county, 1988-92
Sources: American Cancer Society; California Cancer Registry; UC Irvine Department of Medicine, Epidemiology Division.