However, this does not always work for kidney cancers, and currently, there is no way to predict if it will be effective in an individual patient.
In a new study, published in Cancer Cell, scientists analyzed 115 tumor samples from 15 people with metastatic clear cell renal cell carcinoma who received the immunotherapy drug nivolumab.
“Analysing multiple samples from each patient, both from different parts of the kidney tumor and from tumors that have spread to other organs, is critically important. It’s known that molecular information in kidney cancer is distributed like a mosaic within the tumor – such that taking a single sample may not capture all the information needed for a comprehensive analysis,” says Lewis Au, co-lead author, oncologist, and research fellow in the Cancer Dynamics Laboratory at the Crick.
Researchers took tumor samples at various stages of cancer treatment: before immunotherapy, nine weeks after treatment started, after surgery when the tumor was removed, and if the treatment stopped working. For three individuals, tumor samples were also collected after the patient had died.
This was enabled through the PEACE post-mortem research program which provides a unique opportunity to study tumors that have spread to other organs, which are not amenable to be sampled during life.
Within the samples collected, the team looked at different tumor characteristics and measures of immune response to see if any corresponded to immunotherapy.
These included the number of different mutations present in the tumor at diagnosis and whether specific retroviral components, viral DNA present in the human genome, were expressed.
They found that the increased number of specific ‘clonal’ T cell receptors, proteins on the surface of T cells, present in the tumor before treatment, was linked to a greater chance of positive immunotherapy response.
If these T cell receptors were maintained during treatment, this was the strongest indicator that treatment would be effective.
This study also shows how in-depth studies of cancer biology within clinical trials can be incredibly powerful and also why this immunotherapy sometimes works and sometimes doesn’t.
There is a specific T cell response that increases the chance of effective treatment. With this deeper biological knowledge, it might be possible to find new cellular or combination therapies that increase the chance of survival for our patients.
Immunotherapy has transformed our ability to treat certain cancers like melanoma skin cancer, kidney cancer, and lung cancers. But there’s still a lot of research to do to help us understand the precise ways it works and why it’s effective in some patients and not others.
Source: Medindia
