A minimally invasive technique that examines cells swabbed from the cervix or uterus has the potential to detect the early presence of ovarian cancer. The fifth leading cause of death in women in the US, ovarian cancer often goes undetected and is difficult to treat in its late stages. No reliable early detection method for this deadly disease currently exists. Conducting a clinical study, researchers from Northwestern University and NorthShore University HealthSystem investigated cells taken from the neighboring cervix or uterus of patients with ovarian cancer. Although the cells appeared normal under a standard microscope, using partial wave spectroscopic (PWS) microscopy enabled the group to view diagnostic changes within the cell. The technique, developed by Vadim Backman of Northwestern, uses light scattering to examine the architecture of cells at the nanoscale and can detect minute changes that are the earliest known signs of carcinogenesis. These changes can be seen in cells far from the tumor site — in a biological phenomenon known as the “field effect” — or even before a tumor forms. Vadim Backman of Northwestern University has developed a minimally invasive technique that examines cells swabbed from the cervix or uterus, which has the potential to detect the early presence of ovarian cancer. Courtesy of Northwestern. The study included 26 women, 11 with ovarian cancer and 15 who served as part of a control group. Cell samples were taken using a swab — similar to that of a Pap smear — and were placed on slides and examined using PWS microscopy. The results showed a significant increase in the disorder of the nanoarchitecture of epithelial cells obtained from cancer patients compared with controls for both the endometrium and endocervix studies. “We were surprised to discover we could see diagnostic changes in cells taken from the endocervix in patients who had ovarian cancer,” said Backman, a professor of biomedical engineering at McCormick School of Engineering and Applied Science and a member of the Robert H. Lurie Cancer Center of Northwestern University. “The advantage of nanocytology — and why we are so excited about it — is we don’t need to wait for a tumor to develop to detect cancer.” Backman and his collaborator, Dr. Hemant K. Roy, formerly of NorthShore and now chief of the section of gastroenterology at Boston University School of Medicine and Boston Medical Center, have been working together for more than a decade and conducting clinical trials of PWS at NorthShore for four years. In previous studies, the PWS technique has shown promising results in the early detection of colon, pancreatic and lung cancers using cells from neighboring organs. For the earlier lung cancer study, cells were brushed from the cheek. For the colon, cells came from the rectum, and for the pancreas, cells were obtained from the duodenum. “The changes we have seen in cells have been identical, no matter which organ we are studying,” Backman said. “We have stumbled upon a universal cell physiology that can help us detect difficult cancers early. If the changes are so universal, they must be very important.” If commercialized, PWS could be in clinical use for one or more cancers in approximately five years. “This intriguing finding may represent a breakthrough that would allow personalization of screening strategies for ovarian cancer via a minimally intrusive test that could be coupled to the Pap smear,” Roy said. The research — supported by the National Institutes of Health and the National Science Foundation — was published in the International Journal of Cancer (doi: 10.1002/ijc.28122). For more information, visit: www.northwestern.edu or www.northshore.org