The Mathematics of Cancer Risks

Dr. Katki first worked at NIH while he was an undergraduate at the University of Chicago, where he became excited about the application of statistics to medical research and other fields. After he graduated with a B.S. in Math from Chicago and an M.S. in Statistics from Carnegie Mellon, he worked at the Bureau of Labor Statistics helping to calculate state unemployment rates. But he says that he “always wanted to come back to biological science,” and in 1999, he joined NCI as a Staff Scientist. To further pursue his research interests, he applied to a doctoral program at Johns Hopkins University. He completed his graduate work while continuing to work at NCI, and he earned his Ph.D. in Biostatistics in 2006. His Ph.D. thesis was entitled Extending Mendelian Models That Predict if One has a Disease-Causing Mutation Based on Family History of Disease (pdf). It improved a statistical model for inherited cancer/ovarian risk related to the BRCA1/2 mutation, and he received the Margaret Merrell Award for research by a Biostatistics doctoral student.In 2009, Dr. Katki was appointed a Principal Investigator at NCI. He is currently helping to develop guidelines for cervical cancer screening that incorporate human papillomavirus (HPV) testing with Pap smears. In 2011, he was the lead author on a paper entitled Cervical cancer risk for women undergoing concurrent testing for human papillomavirus and cervical cytology: a population-based study in routine clinical practice. He analyzed extensive data from Kaiser Permanente Northern California (KPNC) to determine that for women aged 30 and older, a negative HPV test provided strong reassurance against being diagnosed with cervical cancer over five years. His work was noted by the American Society of Clinical Oncology (ASCO) as one of the cancer research advances of 2011 to have the greatest impact on patient care. His work was also one of the major reasons underlying the U.S. Preventive Services Task Force (USPSTF) recommendation that women over the age of 30 get screening with both a Pap smear and an HPV test. As Dr. Katki continues to analyze this data, he is providing cancer risk estimates based on combinations of test results over time to inform more detailed evidence-based screening and management guidelines.

Dr. Katki credits the math team at Blair and Takoma Park as critical to his education. The “most important teacher” he had was Darlyn Counihan, who taught magnet math classes and coached the math team at Takoma Park. As Dr. Katki explains, she “made it clear to me that math was about logical reasoning from premises to conclusions, and demonstrating how you get from premises and conclusions.” It was “the first time in my life that I got failing grades on tests.” But the challenges made him a better mathematician, and when he got to the University of Chicago, he found that many more of his teachers were like Ms. Counihan.

In 2009, Dr. Katki returned to Blair to speak at the Magnet Research Convention, although his own senior research project was not particularly notable. He partnered with a classmate to develop a substitute for a computer mouse that could be used by a person who had impaired motor control of his hands. But the device they developed, trying to use head movements to control the mouse cursor, proved to be inconvenient and difficult to use. He still learned a lot in the process, however, and Dr. Katki believes that the “greatest thing about the Blair Magnet were the friends that I made.” Out of all the places he has studied and worked, he thinks that his peers in the Magnet provided “the most intellectual stimulation.”