The back deck of Katherine Kennedy's Point Loma home looks out over San Diego Bay. To the east is Lindbergh Field; Naval Base Point Loma is to the west; and if you threw a baseball straight ahead and far enough, it would land in the middle of North Island Naval Air Station's crisscrossing runways. Kennedy's new set of patio furniture sits covered by canvas tarps to protect it from the jet-fuel residue she suspects ate away at the last set.
Since 2001, at least a dozen residents living in and around Point Loma's upscale La Playa neighborhood have developed squamous cell carcinoma of the head and neck, a type of cancer that comprises only 3 to 5 percent of all cancer diagnoses in the U.S. For now, public health officials have ruled that a dozen cases of head and neck cancer within the census tract that includes La Playa isn't an unusual number, but residents believe there are more cases yet to be discovered.
It started a few years ago, Kennedy said, when a member of the San Diego Yacht Club, to which Kennedy and her husband belong, was diagnosed with mouth cancer. "He didn't smoke," she said. "It's rare if you're not a smoker to get that.... Eighteen months goes by and another [yacht club member] gets it and goes through the same thing. Then we have another one, and another one, and another one."
Celeste Holthaus' husband, Doug, was one of those guys. Like the other men, Doug doesn't smoke, nor does cancer run in his family. The only thing all these men had in common is that they're Point Loma residents and avid, longtime sailors.
"It got to be this joke down at the yacht club: Don't drink at the bar," said Kennedy, who's also on the board of directors of the Sidney Kimmel Cancer Center. "It started to make no sense." She also heard about people who were not yacht club members who had been diagnosed with the same type of cancer.
"People knew, but no one had really done anything," Holthaus recalls. "People talked and said, "We'll call the National Institute of Health. We'll call the National Cancer Institute.' But nobody did anything."
So Kennedy and Holthaus began collecting data on each diagnosis and organized a community forum in May of last year. Initially, they planned to spearhead a zip-code survey but were told by county health officials that they should send the information they'd collected to the San Diego County cancer registry, located on the campus of UC Irvine, one of 10 regional registries that collects data on cancer cases. That data is then reported to the state Department of Health for statistical purposes.
Holthaus was diligent in how she gathered the necessary data and can still, from memory, sketch out a rough map showing where each individual diagnosed with this particular kind of cancer lives.
"I realized I had a lot to do to make sure I had enough information and make sure I had it organized well enough and intelligently presented so that hopefully they would look at it," she said.
Each year, nationwide, state and local health officials get roughly 1,000 inquiries from people who think they've discovered a cancer cluster in their community. But only between 5 and 15 percent of suspected cancer clusters-nationwide-end up being statistically significant, meaning the number of cancer diagnoses in a certain area exceeds the expected number of diagnoses. Historically, nearly all suspected cancer clusters can only be explained as coincidence, and those that have been linked to environmental causes are usually within an occupational setting.
Dr. Thomas Taylor, a bio-statistician at the UC Irvine cancer registry and one of the scientists who evaluated the Point Loma data, said the first step was to verify that the information Holthaus compiled involved all the same kind of cancer. "If people are concerned, let's say, about breast cancer, and they put a colon cancer and a lung cancer in with it, then epidemiologically, that doesn't make much sense," he said. Also, the cases all needed to be residents who lived within a defined area, so a member of a local yacht club who'd contracted the same kind of cancer but who lived in Clairemont was not included in the final number of cases.
Registries then use census data to determine what, over a five-year period, the "expected" number of cases of a particular kind of cancer would be for a certain area, Taylor said. Because of difficulties associated with collecting information on each cancer diagnosis within a particular area, registry data lags by about three years-so when Holthaus gave UC Irvine information on cases spanning 2001 through 2005, the registry had to go by data spanning 1998 through 2002.
For the 5,000-person census tract that includes La Playa, statisticians determined that from 2001 and 2005, between one and 12 men and up to nine women would be expected to contract head and neck cancer. In other words, the 10 Point Loma cases that the registry evaluated fell well within the expected number of cases. Holthaus received a letter from the director of the cancer registry in November, informing her that there was no indication that incidences of head and neck cancer in the La Playa area should be cause for concern.
Holthaus said registry officials have told her that if she comes up with data on additional cases, they will re-run the numbers. Kennedy says they're aware of additional diagnoses. And though the two women are not looking for a cause, Kennedy was surprised to open the newspaper on Feb. 8 to see a small article about hundreds of thousands of gallons of jet fuel that had leaked into the soil under the Point Loma Naval Base between 1999 and 2003. The public was notified only this February after it was discovered that the leak was coming close to breaching the divide between Navy land and La Playa-Holthaus' home looks out over the Naval Base, and she said she had no idea about the fuel leak. (At a March 20 community forum, Capt. Mark Patton, base commander, said that as far as he knew, the fuel spread had been halted and a toxicologist hired by the Navy said vapor sensors set up around the spill site had so far detected nothing that would pose a health risk to residents.)
But cancer plus a nearby fuel spill has left a lot of La Playa residents concerned. UC Irvine's Taylor doubts there's a link. "My experience over the years is that military bases, nuclear power plants, dumps and other things like that make people more suspicious than they otherwise would be," he said. "I'm not personally aware of any direct link between any of those places and head and neck cancer.
"People want explanations for these things, and I don't blame them. We all want explanations," he said. "The fact is that cancers are very complicated, very different from one patient to the next. The idea that there's one thing in the environment that gives cancer to a bunch of different people, that's sort of been sailed so many times. Cancers are so much more what we've been born with, our genes and what we choose to do with them, our diet, our exercise-stuff like that is much more important than where we live."
Holthaus said right now the focus is not on pinpointing a cause but rather to get a handle on exactly how many residents in the Point Loma area have been diagnosed with head and neck cancer. She and Kennedy are moving forward with their plan to do a full zip-code inventory, even if that means going door-to-door.
"We just want to get information out to people," Holthaus said. "No. 1, if they have it, there's a network of people to help them, and No. 2, to find out of there are more cases so that we do get it recognized such that it will be investigated by the proper agencies and then maybe God knows how many years down the road, something positive will come out of it."