Screening detects ovarian cancer using neighboring cells

Pioneering biophotonics technology developed at Northwestern University is the first screening method to detect the early presence of ovarian cancer in humans by examining cells easily brushed from the neighboring cervix or uterus, not the ovaries themselves.

A research team from Northwestern and NorthShore University HealthSystem (NorthShore) conducted an ovarian cancer clinical study at NorthShore. Using partial wave spectroscopic (PWS) microscopy, they saw diagnostic changes in cells taken from the cervix or uterus of patients with ovarian cancer even though the cells looked normal under a microscope.

The results have the potential to translate into a minimally invasive early detection method using cells collected by a swab, exactly like a Pap smear. No reliable early detection method for ovarian cancer currently exists.

In previous Northwestern-NorthShore studies, the PWS technique has shown promising results in the early detection of colon, pancreatic and lung cancers using cells from neighboring organs. If commercialized, PWS could be in clinical use for one or more cancers in approximately five years.

The ovarian cancer study was published this month by the International Journal of Cancer.

PWS uses light scattering to examine the architecture of cells at the nanoscale and can detect profound changes that are the earliest known signs of carcinogenesis. These changes can be seen in cells far from the tumor site or even before a tumor forms.

"We were surprised to discover we could see diagnostic changes in cells taken from the endocervix in patients who had ovarian cancer," said Vadim Backman, who developed PWS at Northwestern. "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 is a professor of biomedical engineering at the McCormick School of Engineering and Applied Science. He and his longtime collaborator, Hemant K. Roy, M.D., formerly of NorthShore, have been working together for more than a decade and conducting clinical trials of PWS at NorthShore for four years. Backman and Roy both are authors of the paper.

"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."

Ovarian cancer, which ranks fifth in cancer fatalities among American women, usually goes undetected until it has spread elsewhere. The cancer is difficult to treat at this late stage and often is fatal.

"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.