1. Cancer Biology Tumour Markers Tumour Markers Prof. Kenneth Bagshawe FRS

2. Tumour Markers Widest Definition Tumour Markers Widest Definition The concept of tumour markers can mean anything that helps in the diagnosis of cancer The concept of tumour markers can mean anything that helps in the diagnosis of cancer In a more restricted sense it refers to the biochemical detection of cancer In a more restricted sense it refers to the biochemical detection of cancer

3. Imaging Techniques Imaging Techniques Detected by: Detected by: x-ray +/- contrast media x-ray +/- contrast media Ultra sound Ultra sound Computerised Tomography (CT) Computerised Tomography (CT) Magnetic resonance imaging (MRI) Magnetic resonance imaging (MRI) Gamma Camera and radioisotopes Gamma Camera and radioisotopes (Nuclear Medicine) (Nuclear Medicine)

4. Cannon Ball

5. Multiple Metastases

6. Diffuse Metastases-Before and After Chemotherapy

7. Detection of Tumour Markers Detection of Tumour Markers Those detected on cancer tissue Those detected on cancer tissue i) Biochemical methods i) Biochemical methods Oestrogen receptors in breast cancer Oestrogen receptors in breast cancer ii) Genetic methods ii) Genetic methods Mutated genes BRCA1 and BRCA2 in breast cancer Mutated genes BRCA1 and BRCA2 in breast cancer iii) Antibody methods iii) Antibody methods Carcinoembryonic antigen (CEA) Carcinoembryonic antigen (CEA)

8. Secreted by cancers into the blood Detection by : Detection by : Biochemical techniques Biochemical techniques steroids in adrenocortical cancer steroids in adrenocortical cancer Immunoassay Immunoassay proteins, glycoproteins proteins, glycoproteins

9. Ancient History 1848 Bence Jones 1848 Bence Jones Multiple myeloma Multiple myeloma 1929 Ascheim-Zondek 1929 Ascheim-Zondek hCG-trophoblast hCG-trophoblast 1932 Harvey Cushing 1932 Harvey Cushing Pituitary Basophils Pituitary Basophils

10. The First Tumour Marker It is known as Bence –Jones proteinuria, a marker for multiple myeloma a It is known as Bence –Jones proteinuria, a marker for multiple myeloma a malignancy of the plasma cell. malignancy of the plasma cell. Often referred to as a paraproteinuria Often referred to as a paraproteinuria It is a monoclonal gammopathy with any class of immunoglobulin It is a monoclonal gammopathy with any class of immunoglobulin

11. Cancers of Endocrine Organs Adrenocortical Adrenocortical Phaeochromocytoma Phaeochromocytoma Insulinoma Insulinoma Gastrinoma Gastrinoma Carcinoid Carcinoid Medullary Ca Thyroid Medullary Ca Thyroid Cortisol Cortisol adrenaline & nor adrenaline adrenaline & nor adrenaline insulin, C peptide insulin, C peptide gastrin gastrin 5-HIAA 5-HIAA Calcitonin Calcitonin

12. Ectopic product syndromes Cancers sometimes produce substances inappropriate to the cell type of origin Cancers sometimes produce substances inappropriate to the cell type of origin Bronchial carcinomas may produce ACTH, parathormone and Bronchial carcinomas may produce ACTH, parathormone and human Chorionic Gonadotrophin (hCG) human Chorionic Gonadotrophin (hCG)

13. Protein markers of common cancers detected by immunossay in blood Human Chorionic gonadotrophin (hCG) Human Chorionic gonadotrophin (hCG) Pregnancy Pregnancy Trophoblastic disease - Choriocarcinoma Trophoblastic disease - Choriocarcinoma Germ cell cancers of testis and ovary Germ cell cancers of testis and ovary Alfa- feto protein (AFP) Alfa- feto protein (AFP) Germ cell cancers of testis and ovary Germ cell cancers of testis and ovary Hepatoma Hepatoma

14. Protein markers continued Carcinoembryonic antigen (CEA) Carcinoembryonic antigen (CEA) Colon, stomach etc Colon, stomach etc Prostate Specific antigen (PSA) Prostate Specific antigen (PSA) CA125- Ovary CA125- Ovary CA153- Breast CA153- Breast

15. Measurement of Tumour Markers Measurement of Tumour Markers 1930-1963 Bioassays on Urine 1930-1963 Bioassays on Urine 1958 Immunoassays- serum 1958 Immunoassays- serum 1960 Radioimmunoassay- 1960 Radioimmunoassay- serum or urine serum or urine 1968 Immunometric assay 1968 Immunometric assay serum or urine- serum or urine- Commercial Kits Commercial Kits 1975 Dip Stick Tests 1975 Dip Stick Tests

16. What Is An Assay ? Unknown

17. Antibody Production Immunogen (Antigen) Rabbit Immunogen (Antigen) Rabbit Sheep Antiserum Sheep Antiserum Mouse Mouse Horse etc Horse etc Antisera contain many different antibodies directed at Antisera contain many different antibodies directed at one or more sites on immunogen (polyclonal) one or more sites on immunogen (polyclonal) Burnett (1957)- Clonal selection Theory One Cell - identical antibodies One Cell - identical antibodies

18. Antibody Production Kohler & Milstein (1975) Kohler & Milstein (1975) Immortalise an antibody producing cell Immortalise an antibody producing cell by fusion with a malignant cell by fusion with a malignant cell Hybridoma Hybridoma Hybridomas proliferate Hybridomas proliferate Identical (monoclonal) antibodies Identical (monoclonal) antibodies

19. RISING levels of these serum markers indicate disease progression FALLING levels and slowing of rate of increase may indicate response to therapy FALLING levels and slowing of rate of increase may indicate response to therapy BUT interpretation has to take account of the HALF -LIFE (t1/2) BUT interpretation has to take account of the HALF -LIFE (t1/2)

20. Half Life Of Common Tumour Markers Depends On Molecular Weight MW TM T1/2(D) ROUTE MW TM T1/2(D) ROUTE <70 hCG, PSA 2.3 renal <70 hCG, PSA 2.3 renal 70 aFP 6 mixed 70 aFP 6 mixed > 70 all others 10 hepatic > 70 all others 10 hepatic

21. Median Doubling Times reflect different growth rates of cancers CANCER TM T2(D) CANCER TM T2(D) Choriocarcinoma hCG 3 Choriocarcinoma hCG 3 Germ cell aFP 6 Germ cell aFP 6 Breast CA153, CEA 30 Breast CA153, CEA 30 Ovary CA125 30 Ovary CA125 30 Pancreas CA199 30 Pancreas CA199 30 Colon CEA, CA199 30 Colon CEA, CA199 30 Prostate PSA 128 Prostate PSA 128

22. Cell Numbers

23. Time Scale- Cell Numbers

24. Human Chorionic Gonadotrophin- (HCG) C-Terminal Peptide

25. Normal Placental Villi

26. hCG V Cell Numbers

27. Human Chorionic Gonadotrophin (hCG) Normal Pregnancy: Mostly Intact molecule (α and β subunits) Mole, Choriocarcinoma: Fragmented hCG molecules

28. Trophoblastic Tumour

29. Choriocarcinoma

30. Germ Cell Tumour

32. Prostate Specific Antigen (PSA): Age Effect

33. Carcinoembryonic Antigen

34. CEA

35. Radioimmunolocalisation-CEA

36. Therapeutic Application Radiolabelled Antibodies (RIT) Drug-Antibody Conjugates

37. Problems Only a fraction of the i.v injected antibody gets into tumour: Only a fraction of the i.v injected antibody gets into tumour: Most of the antibody stays in blood until excreted or metabolised Most of the antibody stays in blood until excreted or metabolised Heterogeneity of cancer cell: Heterogeneity of cancer cell: not all cancer cells express the marker not all cancer cells express the marker

38. Potential Solutions Antibody directed enzyme prodrug therapy (ADEPT) Antibody directed enzyme prodrug therapy (ADEPT)