Characterizing Cancer

What is the goal of our ongoing quest to discover new biomarkers for cancer therapy? Collectively, we want to improve personalized therapy for our patients. It may sound straightforward, but for oncologists trying to unravel the complexities of patients’ tumors, heterogeneity presents a challenge. Tumor cells often behave differently depending on their location, which means that a single tissue sample may contain several cell types, making interpretation complicated. Worse yet, some cell types may not be present in the sample at all – meaning that a personalized treatment strategy might not tackle a patient’s entire tumor.

Digital spatial profiling (DSP), a novel barcoding approach, aims to address some of these issues by extracting more data from a single tissue sample, potentially overcoming a consistent limiting factor in tumor analysis. “The high plex capabilities of DSP technology enabled us to interrogate many more potential biomarkers than would have been possible on these very small tissue biopsies with standard or multiplexed immunohistochemistry approaches,” says Christian Blank of the Netherlands Cancer Institute. Blank used the technology to investigate how the pre-existing immune status of stage III melanoma predicts treatment response (1).

DSP can profile targets up to their thousands with a high level of precision. The technology has already successfully identified several protein markers that are thought to be involved in predicting response to treatment (1)(2), and although it has only been used for one type of cancer so far, there are plans to apply the technique to other cancers to discover further biomarkers that could be crucial for treatment. Jennifer Wargo of MD Anderson Cancer Center, for instance, is using DSP to quantify protein expression in tumor-infiltrating immune cells before and during treatment (2). “With DSP technology, we were able to discover that both presence of particular immune cell populations and their activation status may be predictive of clinical benefit to this therapy,” she says.

Although DSP is still a novel concept, its results in research are promising. The high sample throughput and multiplexing capacity is scaled to support large-scale clinical trials but, ultimately, it could help pathologists and oncologists characterize individual tumors more fully to identify the best possible treatment for each patient.