Opinion ID: 1381810
Heading Depth: 3
Heading Rank: 1

Heading: Admission of Dr. Naftalis's Expert Testimony

Text: Wyeth and Upjohn argue that the district court erred in admitting the testimony of Dr. Elizabeth Naftalis, Scroggin's expert witness on specific causation. [A]bsent a clear and prejudicial abuse of discretion, we will not reverse a district court's determination on the admissibility of expert testimony. Bland v. Verizon Wireless, L.L.C., 538 F.3d 893, 896 (8th Cir.2008). Federal Rule of Evidence 702 provides for the admission of an expert opinion if it will assist the trier of fact to understand the evidence or to determine a fact in issue, provided the expert is qualified to render the opinion and offers sufficient factual basis for her opinion, forms her opinion on reliable principles and methods, and applies these principles or methods to the facts of the case. Rule 702 reflects a relax[ation of] the traditional barriers to opinion testimony, and the court's inquiry is intended to be flexible. Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579, 588, 594, 113 S.Ct. 2786, 125 L.Ed.2d 469 (1993) (internal quotations omitted). The district court must assess whether the methodology used by the proposed expert is valid and whether it was properly applied. [11] Id. at 592-93, 113 S.Ct. 2786. There is no single requirement for admissibility as long as the proffer indicates that the expert evidence is reliable and relevant. Unrein v. Timesavers, Inc., 394 F.3d 1008, 1011 (8th Cir. 2005). Wyeth and Upjohn did not challenge Dr. Naftalis's qualifications as an expert witness before the district court, and they do not argue that the method she used, differential diagnosis, is not a sound and accepted methodology. Instead, they argue that differential diagnosis cannot be used to prove the cause of breast cancer because no one knows the cause of breast cancer. They note that Dr. Naftalis was not familiar with the details of Scroggin's family history of breast cancer until trial, and they argue that she did not properly account for Scroggin's various risk factors for breast cancer, such as breast density, her age, weight, and her smoking history. Scroggin suffered from hormone-dependent breast cancer. Dr. Mariann Harrington, Scroggin's oncologist, tested the tumors in Scroggin's breasts for hormone receptors to inform her treatment. Both the left and right tumors were one hundred percent positive for estrogen and progesterone receptors. There was no dispute at trial that hormone-receptor-positive tumors are dependent upon hormones for their growth. Moreover, published research had concluded that hormone-receptor-positive tumors need hormones to grow, that menopausal symptoms result from hormone deficiency, and that there is a link between breast cancer and hormone replacement therapy. See Lauzon v. Senco Prods., Inc., 270 F.3d 681, 693 (8th Cir.2001) (noting that scientific reliability can also be shown by proof that the research and analysis supporting the proffered conclusions have been subjected to normal scientific scrutiny through peer review and publication). Knowing that Scroggin's breast cancer was hormone dependent, Dr. Naftalis's differential diagnosis sought to determine the cause of Scroggin's breast cancer by ruling out the two possible sources of these hormones: (1) Scroggin produced the hormones herself, or (2) they came from the hormone replacement therapy she had taken for the past eleven years. Scroggin presented evidence that her menopausal symptoms were relieved by hormone replacement therapy, confirming that her own body was unable to produce sufficient hormones and therefore could not be the cause. [12] The remaining source was the combination of Premarin, Provera, and Prempro. Accordingly, Scroggin presented evidence establishing a causal link between breast cancer and estrogen plus progestin use, particularly for the length of time Scroggin was taking the drugs. We find unpersuasive the contention that Dr. Naftalis's testimony should not have been admitted because Scroggin has some breast cancer risk factors and a family history of breast cancer. Dr. Naftalis sufficiently established that hormones were necessary to the development of Scroggin's tumors and conducted her differential diagnosis from this starting point. Although not necessary to the formation of her opinion, Dr. Naftalis addressed the known causes of breast cancer and possible risk factors. Wyeth and Upjohn argue that this review was insufficient, but Dr. Naftalis's explanations as to conclusions not ruled out went to weight and not admissibility. Id. at 694. Additionally, Scroggin submitted to every available genetic test for breast cancer, all of which came back negative for the most common breast cancer genes. Wyeth's genetics expert testified that he continues to believe that genetics caused Scroggin's breast cancer, but the jury concluded otherwise. Wyeth's and Upjohn's reliance on Bland v. Verizon Wireless, L.L.C. is misplaced. 538 F.3d 893 (8th Cir.2008). In that case, expert testimony was offered to show that the plaintiff's recent exposure to freon caused her exercise-induced asthma. Id. at 897. The exact cause of exercise-induced asthma is not known, and the plaintiff's expert could not provide a reliable opinion as to what caused the plaintiff's asthma. Id. at 898. The proximity in time between the plaintiff's exposure to freon and her resulting asthma was the only basis for her doctor's opinion; the doctor failed to investigate other possible causes, including Bland's home or other environments. Id. Conversely, Dr. Naftalis was able to testify that Scroggin's breast cancer would not have developed without hormone replacement therapy because Scroggin's body was not producing sufficient amounts of hormones to allow hormone-receptor-positive tumors to develop. Thus, Dr. Naftalis ruled out the other possible cause of Scroggin's breast cancer, and her expert testimony was properly admitted. [13] Wyeth and Upjohn had the opportunity to expose the testimony's weaknesses through vigorous cross-examination and the presentation of contrary evidence. See Daubert, 509 U.S. at 596, 113 S.Ct. 2786.