The rate of illness and death from cancer in California overall is lower than that of the nation as a whole, while cancer incidence in Los Angeles County is lower than in any other region of the state, a series of state Department of Health Services reports said Thursday.
"Both in incidence and mortality California is in better shape than the rest of the country," State Health Director Molly Joel Coye said as she released the findings.
Coye said it will take more research to determine why California has such a good showing, but officials suspect the state's ethnic diversity may be a major factor. She said Latinos and Asian-Americans, who make up about 37% of the state's population, are less likely to develop cancer than either blacks or whites.
Likewise, John L. Young, chief of the department's cancer surveillance section, said the ethnic composition of Los Angeles County may account for the fact that the area shows lower cancer rates than any of nine other regions of the state. But he said officials will be able to make a better determination of ethnic influences after they study new census data expected later this summer.
Coye cautioned that cancer is still taking a heavy toll on Californians and that among some groups--particularly black males--the risk of developing the disease is alarmingly high.
In 1989, the year studied in the new reports, 105,416 cases of cancer were diagnosed in California. In the same year some 48,107 Californians died of cancer, making it the second leading cause of death in the state after heart disease.
Data for the reports on cancer incidence and related deaths was gathered by the California Tumor Registry, which collects cancer-incidence reports from doctors and hospitals.
The figures showed that the incidence of cancer statewide was 337 cases for every 100,000 residents. The national rate is 377 cases. Cancer deaths, the reports said, occurred at a rate of 153 for every 100,000 residents, as compared with the national death rate of 173.
In Los Angeles County, the cancer incidence rate was 311 per 100,000 residents, while in the Sacramento region, which showed the highest incidence in the state, the rate was 364. The Orange County region incidence rate was 353 per 100,000 residents. The rate for the San Diego region, which includes San Diego and Imperial counties, was 342.
State officials said they were surprised to discover a 2% drop in the rate of diagnosis and the rate of death from 1988 to 1989.
"This is something that we're puzzled by because we don't see a similar drop in the national rate," Young said.
Preliminary data for 1990 indicates that the rates are going to return to previous levels, he said, leading officials to believe that the 1989 drop was "a temporary blip."
Coye said that while research is under way to determine genetic and dietary links to cancer, the question of who gets access to care and early screening programs may be far important. She said poor blacks' limited access to medical care may account somewhat for the high incidence of cancer among African-Americans.
For example, she said, health officials know that cervical cancer is usually diagnosed at a much later stage among African-American women than among white women.
"What that means is that the cancer is more developed at the point that the African-American women come in to see a doctor and are diagnosed as having cancer," she said.
The reports show that the lifetime risk of cancer for black males is 38.6%, meaning that nearly two of every five black men is expected to develop the disease. In contrast, the cancer risk is 31.2% for white males and 20.1% for Latino males.
For women, the cancer risk is lower than for men, but white women are more likely to get the disease than either black or Latino women. The cancer risk was 27.8% for white females, 26.3% for black females, and 17.3%.for Latinas.
Breast cancer was the most frequently diagnosed type of cancer among women while prostate cancer was the most frequent for men.
Coye said California's relatively low cancer death rate is also an indication to her that intervention and prevention programs in the state have been working.
"Getting early detection and early intervention is absolutely critical, whether we're talking about breast cancer or prostate cancer," she said.