CTC subtypes and prostate cancer progression

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Published: 23 Nov 2016
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Dr Yong-Jie Lu - Barts Cancer Institute, London, UK

Dr Lu speaks with ecancertv at NCRI 2016 about a study looking at capturing circulating tumour cells with epithelial and mesenchymal features for prostate cancer prognosis.

The aim of this study is to show that, in prostate cancer, circulating cells expressing the mesenchymal marker vimentin (VIM) are cancer cells, and to correlate different CTC subtypes to prostate cancer progression.

This study we tried to use circulating tumour cells to help with cancer diagnosis, prognosis and even monitoring the therapeutic response. Because previously most of the diagnoses and prognoses are based on the tissue biopsy, we have to look at the tissue sample to do the diagnosis but that usually gets the tissue, for example the prostate, and it’s very time consuming and it also can be a very painful procedure. So we can’t just frequently take tissue biopsies to do that. But the use of blood samples, blood samples, people get used to just blood tests, that’s easy to take the sample and if we can get the circulating tumour cells and we can properly analyse them so we can use them and frequently take the blood and just see during treatment what the genetic and other biological features are there. We can treat maybe more individualised and timely and that’s what the current code of practise medicine is doing.

Can you give examples of the kinds of information we can get from these tumour cells?

That’s always depending on which stage we take the sample. For example, before and during the diagnosis and we just take to see if the circulating tumour cells are already there and that may help the cancer diagnosis and particularly can be an even earlier diagnosis. Of course I focus on my own work on prostate cancer diagnosis which always can be diagnosed earlier but for many other cancers frequently early diagnosis is an issue that may help and just take the blood to find the circulating tumour cells to help early diagnosis. Also in prostate cancer we mainly work on the later stages of disease and just based on CTCs to see how good the prognosis is, that’s currently our work. Based on even the most CTCs, that means cancer cells already get into the blood and spread to the body and form the metastases, that’s more progressed, usually that may be advanced disease and there’s a high mortality rate. So that’s something we have to just stratify the treatment – who we should treat heavily and who may not be necessary.

Have you found specific results yet?

Currently we’ve found with other CTCs and particularly there’s some different types of CTC. Previously with CTCs many people worked on them because carcinoma is a single cell type and we worked out that we can detect the cell that has transformed into the mesenchymal cell type that is moving to the cancer metastasis process. We can detect those and those link to the cancer prognosis even more strongly than the epithelial type of CTCs.

What do you think the future holds? Perhaps people getting regular blood tests to screen for cancer?

Yes, that’s what we are aiming to do. First we can base it on one blood test to see if they’ve got more of these circulating tumour cells so just based on this we will see if they have a bad prognosis for prostate cancer so we can treat them heavily. And for people with less prostate cancer half of them if they’re early stage and it’s not very aggressive and they can survive more than ten years it may not be necessary to be treated until they progress. So that’s something we can just diagnose it and call the treatment. During the treatment we can frequently take a blood sample that [?? 4:19] and then just monitoring the CTCs and see how they respond to the therapeutics – should we change the therapeutics or maybe even according to this and during that time we may have to think if we should stop the treatment because it isn’t efficient until there are more tumour cells come and we treat them again.

Are there any cost implications?

Yes, surely there’s a cost issue. Currently there are lots of CTC isolation systems have been developed and each of those systems is quite expensive. So we got [?? 5:03] support from we had in collaboration with [?? 5:05], they have the particular type of CTC isolation platform. So we got those donated by them; it’s not donated always, it’s just support in a collaboration, they have free rent of these machines so we access that freely. During the CTC analysis there are some cost issues but those costs are relatively much cheaper compared to lots of other next generation sequencing analysis. There is still a cost issue.

Another I have seen, I have to say, we currently look at how many circulating tumour cells, which are called CTCs, are in the blood and we did also a few biomarkers, protein markers and genetic markers in the CTCs. But in the long run we may have to do the whole genome or what’s in the CTC genomics change and the whole transcriptome changes, that’s something we are trying to develop as well. That will be much more expensive.