Hoping to identify markers that could predict future cancer risk, his team analyzed and compared pathology reports and health information from people with DCIS who did and didn’t go on to develop invasive breast cancer. The study’s first author, Mathilde Almekinders from Wesselings’ group, had the idea of looking in detail at adipocytes – the fat cells surrounding the breast ducts. Despite being able to influence the behavior of their neighboring cells, adipocytes are not typically the focus of breast cancer studies.
Two key factors were identified as driving the progression of DCIS to breast cancer: the size of the fat cells surrounding the DCIS lesion and the expression of the COX2 protein. If patients had small adipocytes coupled with low levels of COX2, their risk of developing breast cancer was very low (2.6%) – comparable to that of the general population. But individuals with high levels of COX-2 and larger adipocytes were estimated to have around a 1 in 4 chance (28%) of being diagnosed with invasive breast cancer within 15 years.
Someday, measuring fat cell size and COX2 expression could help predict whether or not someone’s DCIS will progress to invasive breast cancer. This could eventually mean thousands of women around the world might safely consider a ‘wait and see’ approach to monitor their DCIS and could be spared treatment until it is necessary, potentially transforming their quality of life.
The research team is now collaborating with several clinical trials that look to predict breast cancer risk in people with DCIS, hoping to add adipocyte size and COX2 expression to the criteria being checked. “[For people with DCIS,] there has to be a way to avoid such heavy medical interventions without compromising on an excellent health outcome,” Jelle describes. “I hope we’ve found it.”
This research was financially supported by the Dutch Cancer Society and Cancer Research UK.