Scientists Measure Metastasis Diversity to Predict Ovarian Cancer Survival

Scientists at the Institute of Cancer Research, in collaboration with the Sun Yat-sen University Cancer Centre in China, have developed a new computerized test that measures metastasis diversity to predict ovarian cancer survival.

The new test, described in a paper published in the journal Oncotarget, uses software designed to study plant and animal ecosystems. By measuring the levels of diversity among cells in the environment around secondary tumors, the test could identify patients who have the most life-threatening disease.

"We used to think of tumours as simply a collection of cancer cells, but we now know that they are often complex ecosystems made up of different types of healthy cell, too," explained Dr Yinyin Yuan, Team Leader in Computational Pathology at the ICR, in a press release. "Our study has revealed that diverse cell populations at the sites of cancer spread are a clinically important feature of particularly aggressive ovarian cancers."

The newly developed test gives a score for metastasis diversity, or MetDiv, by assessing the cells "ecosystem" at sites where the ovarian cancer has spread around the body. A low score was given if the patient's sites of cancer spread have one dominant cell type, while a high score is given to patients with sites of spread that have more diverse cell population containing immune or connective tissue cells.

To try out the new tests, the researchers analyzed 192 secondary tumors that had spread to the area around the ovary, peritoneal cavity, lymph nodes or appendix, from 61 women with more than one metastasis treated at Sun Yat-sen University Cancer Centre in China.

The researchers discovered that just 9 percent of the women who have receive a high score survived five years from diagnosis. On the other hand, 42 percent of the women who have received a low score in the test survived five years from diagnosis. This suggests that survival is greater among women who received low diversity scores compared to women with high scores.

With their findings, the researchers believe that a high diversity score could be a stronger predictor of poor survival than any of the clinical factors currently used to try to assess a woman's prognosis.