‘Patchwork’ ovarian cancer is more likely to resist therapy

Researchers from the Cancer Research UK Cambridge Institute, Cambridge University and Addenbrooke’s Hospital (all Cambridge, UK) have reported that patients with serous ovarian cancers exhibiting spatial and temporal heterogeneity were more likely to die sooner, develop treatment resistance and display disease recurrence. The study is the first of its kind to link tumor heterogeneity in a solid tumor to survival rates.

The research, which was published in PLOS Medicine recently, analyzed DNA from 135 samples of serous ovarian cancer that were isolated from 14 patients undergoing chemotherapy. The researchers discovered that ‘patchwork’ tumors containing a variety of genetically different cells were more likely to resist therapy and reduce life expectancy than less varied tumors.

Genetic mutations linked to drug resistance in some parts of the tumors were also identified before chemotherapy began. This finding displaces the previous belief that chemotherapy causes these genetic adaptations.

James Brenton, lead researcher from the Cancer Research UK Cambridge Institute, commented: “Our research is important because it helps make sense of the genetic chaos inside tumors. It’s another step closer to cracking the code on cancer biology so that we can understand sooner how patients will respond to treatment – and how to develop better drugs for this hard to treat cancer in the future.”

Cancer Research UK is funding research for developing screening methods for ovarian cancer to help enable earlier diagnosis. Neil Barrie, Cancer Research UK’s senior science information manager, added: “Finding out more about how tumors evolve and what this means for patients could help us find a way to cut off cancer’s first steps.”

Sources: Schwarz RF, Ng CKY, Cooke SL et al. Spatial and temporal heterogeneity in high-grade serous ovarian cancer: a phylogenetic analysis. PLOS Medicine DOI: 10.1371/journal.pmed.1001789 (2015); Cancer Research UK press release