JAN. 27–SANTA CLARA, Calif.–A respected cancer researcher Monday told jurors in the IBM toxics trial that exposure to cleanroom chemicals did not cause breast cancer in a former employee suing the computer giant.
Brian Henderson, professor of preventive medicine at University of Southern California, is a world-recognized researcher on the genetic causes of hormonal cancers such as breast and prostate cancer. Testifying for IBM, he said he did not believe that plaintiff Alida Hernandez’s breast cancer was triggered by toxic chemicals used at IBM’s San Jose manufacturing plant.
Hernandez, 73, and James Moore, 62, are suing IBM, contending that they developed cancer after IBM knowingly exposed them to chemicals at the Cottle Road facility.
According to the Mercury News of San Jose, Henderson told jurors the causes for breast cancer are genetic errors that occur when cells replicate, and that higher and prolonged exposure to the hormone estrogen is one major cause of cellular replication. He presented research on the biggest risk factors for breast cancer, all of which are based on a woman’s level of estrogen exposure.
Women at greater risk for breast cancer due to higher estrogen levels include those who start menstruating early with regular cycles, women who do not give birth, women who begin menopause later than 50 or women who have been on hormone-replacement therapy. Another risk factor is obesity after menopause, because certain enzymes in body fat make estrogen, he said.
Henderson said Hernandez started menstruating at age 9, which he said was earlier than the average age of 12 1/2. He also said that even though Hernandez had a hysterectomy at age 48, he said that was the normal age when many women stop menstruating.
Hernandez also was taking various hormone-replacement therapies, which many women had been advised to take during or after menopause, to help treat symptoms like hot flashes. Hernandez was on hormone-replacement therapies for about 11 years. Henderson said he would classify Hernandez as obese, based on her weight and body mass index, from 1978 until 1993, when she was diagnosed with breast cancer.
“The important thing in her case is that she began to menstruate very early and often, with regular periods,” Henderson said. “I am reasonably certain that her breast cancer is related to the amount of estrogen that she makes herself or related to the hormone replacement therapy.
On cross-examination, the plaintiffs’ attorney, Richard Alexander, asked Henderson if he was very familiar with chemicals or organic solvents. Henderson said he had quite a bit of experience with chemicals. Alexander then pointed out that in his deposition, Henderson was not able to identify on a list of chemicals which ones were organic solvents.
“I am not an organic chemist; that is not my area of expertise,” Henderson said.