Linking immunity and cancer progression

A subset of ovarian tumours have the ability to avoid attack by the immune system, increasing their ability to grow and metastasise.

A team of scientists led by Dr Andrew Stephens, Head of the Ovarian Biomarkers Laboratory at Prince Henry’s Institute (PHI) in Melbourne, found that some high-grade serous ovarian tumours modify the signalling protein or chemokine, CXCL10, to suppress attack through normal immune responses.

White blood cells commonly infiltrate solid tumours and play a role in the spontaneous regression of some cancers.

“In normal circumstances, CXCL10 encourages white blood cells to attack tumour tissue. However, we found that some ovarian tumours are able to modify CXCL10 to prevent this from happening,” said Stephens.

Ovarian cancer is the eighth most common cancer in women in Australia. High-grade serous ovarian cancer is the most common type. Women with this cancer type are usually diagnosed with extensive peritoneal metastases and less than 30% survive for five years post-diagnosis.

According to Stephens, as well as highlighting the well-established link between immunity and cancer progression, the research offers an explanation for how some ovarian tumours block the body’s early anti-tumour immune responses, allowing the tumours to grow and metastasise.

“We have known for some time that there is a link between immunity and cancer progression. This research increases our understanding of how some tumours manage to overcome the body’s anti-tumour immune responses, and possibly promote their spread to other areas of the body,” said Stephens.

The team is now moving to trial therapies targeting this tumour-specific modification of CXCL10 - something Stephens believes could lead to a new approach in treating some types of ovarian tumours.

“Our next goal is to determine whether this approach might complement existing treatments. By promoting increased immune recognition and destruction of tumour cells, we believe that combination therapies could lead to significantly better outcomes for patients.”

Stephens and the PHI Ovarian Cancer Biomarkers Laboratory receive funding from the Ovarian Cancer Research Foundation for the ongoing development of an early ovarian cancer detection test.

The findings were published in the International Journal of Cancer.