Liquid Biopsy

Its about importance of liquid biopsy and its utility in diagnosis of cancer. a new way of early diagnosis.

1. LIQUID BIOPSY Dr. Manan Shah Dr. ML Harendra Kumar

2. CONTENTS Introduction Definition What comes under liquid biopsy Circulating tumor cells (CTCs) Circulating tumor DNAs ( ctDNAs ) A new addition in liquid biopsy Indications of liquid biopsy Comparisons of somatic mutation expression in ctDNAs and primary tumour Tumour biopsy & liquid biopsy Summary References

3. Molecular diagnostic scheme representing routine biological specimens and their molecular alterations.

4. INTRODUCTION The diagnosis of cancer has undergone a paradigm shift. No longer is cancer diagnosed only based on morphological parameters. More and more the diagnostic algorithm is supported by immunohistochemical and molecular alterations at the DNA, mRNAs, miRNAs and proteomic level.

5. INTRODUCTION Multiple platforms and technological advances enable faster and cheaper analysis of all these as well as the whole genome. Recent scientific advances in understanding circulating tumor cells, cell-free DNA/RNA, and exosomes in blood have laid a solid foundation for the development of routine molecular ‘liquid biopsies’.

6. INTRODUCTION This approach provides non-invasive access to genetic information – somatic mutations, epigenetic changes, and differential expression – about the physiological conditions of body and diseases . Liquid biopsy has the potential to provide information about cancers without invasive biopsy, using circulating biomarkers.

7. INTRODUCTION It opens a valuable avenue for cancer screening and monitoring. With the rapid development of highly sensitive and accurate technologies such as next-generation sequencing , molecular ‘liquid biopsies’ will quickly become a central piece in the future.

8. INTRODUCTION These include proteins, RNAs and DNAs. They can be used in, Detection Diagnosis Monitoring and Detection of recurrence of cancer. While protein-based tumour markers have been used in routine pathology for many years, the ability to detect mutations in circulating DNA is relatively new.

9. DEFINITION Liquid biopsies are non-invasive blood tests that detect circulating tumour cells (CTCs) and fragments of tumor DNA that are shed into the blood from the primary tumour and from metastatic sites.

10. Circulating tumor cells

11. CIRCULATING TUMOR CELLS During late 19 th century, T.R. Ashworth first described the presence of epithelial cells in the blood of a woman with metastatic breast cancer that were similar in appearance to her primary tumor cells. Indeed, many patients with a variety of solid tumors, including breast cancer, have detectable cancer cells circulating in the bloodstream, so-called circulating tumor cells (CTCs).

12. CIRCULATING TUMOR CELLS CTCs represent a rare cell population in the blood, typically less than 10 cells/ mL compared with 1 million WBCs/ mL However, the detection of CTCs within a routine blood specimen provides an opportunity to monitor cancer non-invasively, in essence a liquid biopsy.

13. Circulating tumour cell (CTC) enrichment technologies.

14. Analysis of CTCs Yu et al. (2011) J Cell Biol

15. Circulating tumor dna s

16. Exosomes / microvesicles

17. Exosomes are actively released vesicles (carrying RNA, DNA and protein) and can function as inter-cellular messengers.

18. A new addition in liquid biopsy…..

19. TUMOUR EDUCATED PLATELATES

20. Besides tumor cells and their products, normal cells present in the tumor microenvironment are also released into the blood stream. These cells can harbor important information about the tumor.

21. Among which platelets have been studied extensively and gave promising results. The biology behind this new diagnostic role of Tumor Educated Platelets (TEPs) is the well-known interaction between blood platelets and tumor cells

22. This interaction affects not only the expression of relevant genes in tumor cells, but also alters the RNA profile of blood platelets. mRNA sequencing of TEPs can be distinguished from the platelets of healthy individuals.

23. INDICATION OF LIQUID BIOSPY To monitor residual disease in patients with known mutations in the primary tumor. To monitor treatment efficacy in patients To monitor disease progression and tumor evolution (i.e. development of tumor resistance).

24. Help the physician explore other options of treatment when the patient is resistant to current therapies. Provide an alternative method for biopsy when tissue is difficult to obtain or not available, or when the primary site of metastatic disease is unknown.

25. It also provide an alternative method for biopsy when the quantity of tissue obtained in a biopsy sample is limited and traditional molecular genotyping is requested. Provide prognostic information.

26. CANCER AND SOMATIC MUTATIONS The majority of cancers arise after a series of somatic gene mutations that accumulate during an individual’s lifetime Identifying and understanding the somatic alterations in an individual’s tumor can be crucial in cancer diagnosis and in planning personalized cancer treatment, monitoring response to therapy, and identifying cancer recurrence

27. CANCER AND SOMATIC MUTATIONS Moreover, as a tumor progresses, some times it continues to acquire additional alterations that can affect the response to therapeutic agents such as chemotherapy or targeted therapies. Distant metastases can harbor unique genomic characteristics not detectable in the corresponding primary tumor of the same patient

28. CANCER AND SOMATIC MUTATIONS Moreover, metastases located at different sites show a considerable intra-patient heterogeneity. Thus, the mere analysis of the resected primary tumor alone (current standard practice in oncology) or, if possible, even re-evaluation of tumor characteristics based on the biopsy of the most accessible metastasis may not reveal sufficient information for treatment decisions

29. Novel diagnostic biomarkers used in the clinic for various types of cancers and their targeted drug therapy.

30. Is this the end of tissue biopsies? “Tissue biopsy will remain the gold standard for the next couple of years. As scientific knowledge advances, researchers are learning more about the potential of liquid biopsies to detect mutations.

31. At the moment, liquid biopsies are recommended when a tissue biopsy is difficult, such as in the case of lung cancer, or when the original site of the disease is unknown.

32. Liquid biopsies have a powerful role in helping patients get to the right treatment.

33. CONCLUSION Molecular analysis of cancer is required to optimise patient treatment New methods such as next generation sequencing show immense promise for the future Liquid biopsy is coming of age and will change practice – it will enable oncologists to use drugs intelligently to combat changes in individual cancers as they happen

34. references Tumor-Educated Platelets as Liquid Biopsy in Cancer Patients (PDF Download Available) . Available from: https://www.researchgate.net/publication/284112407_Tumor-Educated_Platelets_as_Liquid_Biopsy_in_Cancer_Patients [accessed Jul 18, 2017].

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