TUMOR MARKERS

DEFINISI

• Substansi yg terdapat dalam atau diproduksi oleh tumor, diproduksi host sebagai respons terhadap tumor

• Untuk mengetahui keberadaan tumor dg pengukuran dalam darah, cairan tubuh lain

Pembagian Tumor Marker (TM)

• Tumor specific proteins• Non-specific proteins /marker yang terkait

dengan sel malignant• Cell specific proteins yang diproduksi

berlebihan oleh sel malignant

Tumor specific proteins

• Hanya diekspresikan oleh sel tumor• Contoh: onkogen yang ditranslokasikan

pada gen lain menyebabkan penyatuan protein baru shg terjadi malignant clone:– Philadelphia chromosome in CML, t(9;22)

(q34;q11) bcr/abl translocation– T(8;21) acute non-lymphocytic leukemia,

t(15;17) APL

• Hematological malignancies

Non-specific proteins

• Oncofetal proteins ： diekspresikan oleh sel akibat dari de-deferensiasi sehingga menyerupai karakterikstik embrionik– α-FP ： testicular, ovarian cancer – CEA ： many GI tumors

Cell specific proteins

• Protein yang normal terdapat pada sel tertentu, tapi diproduksi berlebihan oleh sel tumor tertentu

• PSA ： prostate cancer

Tipe TM

• Enzymes and isoenzyme.• Hormon.• Immunoglobulin• Antigens (oncofetal)• Reseptor• Onkogen• Genetic markers.

Enzym&Isoenzym

• PLAP (Placental Alkaline Phosphatase)

Membedakan sumber tumor dari hati, tulang atau germ cell

Non diagnostik, mengkonfirmasi keganasan• LDH (Lactic Dehydrogenase)

Semua tumor memproduksi LDH

isoenzim: LDH1-5

Isoenzym LDH

• LDH1: 18.1% -29% of the total (heart, red

blood cells and kidneys)• LDH2: 29.4% -37.5% of the total (heart, red

blood cells and kidneys) • LDH3: 18.8% - 26% of the total (lungs) • LDH4: 9.2% -16.5% of the total (liver and

skeletal muscles) • LDH5: 5.3% to -13.4% of the total (liver and

skeletal muscles)

Hormon

• Insulin diproduksi oleh islet cell tumor, • Calcitonin diproduksi medullary thyroid

carcinoma• Katekolamin: pheochromocytoma.

Imunoglobulin

• Produksi dari monoklonal imunoglobulin merupakan karakter dari Multiple Myeloma

• Para protein: lamda, kappa light chain atau subtipe imunoglobulin lain

• Merupakan indeks dari volume tumor

Onkofetal antigen

• Marker dari antibodi monoklonal dan antisera poliklonal

• Substansi onkofetal terdapat pada embrio/fetus, menurun pada dewasa, timbul pada tumor

• Oncogenes

ras, HER-2/neu, bcl-2, c-myc• Suppressor genes

Retinoblastoma, p53, BRCA1 and 2• Receptors

ER/PR

Kriteria ideal TM

• Spesifik untuk tumor tertentu• Tidak terdapat pada orang sehat• Dapat terdeteksi pada cairan tubuh dengan

cepat• Sensitivitas tinggi: dpt mendeteksi tahap

awal penyakit• Positive dan negative predictive value

optimal• Berkorelasi dg massa tumor dan prognosis

Kegunaan TM

• Skrining pada populasi yang beresiko dan diagnosis

• Menentukan prognosis• Mendeteksi rekurensi, dan memonitor

respons terhadap terapi

Spesimen untuk TM

• Serum• Plasma• Urine• Sel• Jaringan

harus disimpan dalam keadaan beku dengan nitrogen liquid dengan suhu -70°C

Determination of tumour markers

• Immunochemistry• Radio immune assay – RIA, IRMA• Enzyme immune assay - ELISA, EIA, • Fluorescence assay - FPIA, TRACE• Chemiluminiscence assay - CLIA

Ca 15-3

Ca 15-3

• High molecular weight mucin glycoprotein (MUC-1)/polymorphic epithelial mucin (PEM) the protein part of which is encoded by the MUC1 gene in humans

• MUC1 mucin is a transmembrane glycoprotein found on the luminal surface of the normal glandular epithelium.

• The transmembrane glycoprotein group includes MUC1,MUC3, MUC4, MUC10-18

• MUC2, MUC5AC,MUC5B, MUC6, MUC7, MUC8, MUC9, and MUC19 form the group of soluble (gel forming) glycoproteins.

MUC-1

• It is a long, rigid, and negatively-charged structure extruding from the cell membrane

• MUC1 aids the lubrication of epithelial surfaces, protects against dehydration, and barrier to infection

• MUC1 was first isolated from the human breast milk and has been localized to the apical surface of normal epithelial cells of the breast, salivary glands, and lung

STRUCTURE OF MUC1

• Consists of a protein containing highly glycosylated and unglycosylated regions.

• The MUC1 protein core consists of variable number of tandem repeats (VNTR) of 20 aminoacids sequences.

• Carbohydrate side-chains in mucins are attached by an α1,3 linkage between N-acetylgalactosamine and the oxygen atom of serine or threonine.

• MUC1 is up-regulated and secreted in larger quantities from a variety of malignant tumors.

• An abnormal number of shorter carbohydrate side-chains in cancer associated MUC1 distinguish it from MUC1 in normal tissues.

• Regions of the protein core in MUC1 are consequently exposed, and cancer-associated MUC1 is thereby made anti-genically distinct from MUC1 found in normal epithelia.

MUC1 IN BREAST CANCER

• MUC1 is a serum marker useful for detecting recurence or prognosis in breast cancer patients as serum levels increase.

• Studies show that MUC1 serum levels increased in breast cancer patients with distant metastasis, while it was not significantly elevated in breast cancer patients without metastasis

• This phenomenon may be due to circulating MUC1 expressing tumor cells that break off from the primary site and travel to distant sites.

• CA15-3 (MUC1 mucin glycoprotein) is used only for monitoring patients in advanced stages of disease, as it lacks sensitivity for early stage disease.

• Concentrations of CA15-3 are elevated in 10% of patients in stage I, 20% in stage II, 40% in stage III, and 75% in stage IV.

• A 5-10 fold increase in CA15-3 indicated the presence of metastasis disease.

• patients with MUC1-expressing tumors showed poorer survival rates than those with MUC1-negative tumors.

• MUC1 is known to suppress the killing activity of target cells by natural killer (NK) cells, and cytotoxic T cells (CTL)

• Increased CA15-3 can be found in a small percentage of healthy people and in patients with benign disease, such as chronic hepatitis, liver cirrhosis, and sarcoidosis

• It is present in a variety of adenocarcinomas of breast, colon, lung, ovary, pancreas.

• CA15-3 may not be suitable or early diagnosis and early prognosis of breast cancer.

Effect of mucins on the immune system

Ca Mammae

• Sel pada mamae yang tumbuh tidak terkontrol gumpalan

• Malignant /benigna• Malignant Ca

Mammae

TNM criteria

T = Primary TumorTis = carcinoma in situT1 = less than 2 cm in diameterT2 = between 2 and 5 cm in diameterT3 = more than 5 cm in diameterT4 = any size, but extends to the skin or chest wall

N = Regional Lymph nodesN0 = no regional node involvementN1 = metastasis to movable same side axillary nodesN2 = metastasis to fixed same side axillary nodesN3 = metastasis to same side internal mammary nodes

M = Distant MetastasisM0 = no distant metastasisM1 = distant metastasis

Clinical staging

•   • T • N • M • 5-Year Survival

• Stage 0 • Tis • N0 • M0 • > 95%

• Stage I • T1 • N0 • M0 • Overall = 85%

• Stage II •   •   •   • Overall = 66%

• (Stage IIA) • T0 • N1 • M0 •  

•   • T1 • N1 • M0 •  

•   • T2 • N0 • M0 •  

• (Stage IIB) • T2 • N1 • M0 •  

•   • T3 • N0 • M0 •  

• Stage III •   •   •   • Overall = 41%

• (Stage IIIA) • T0 • N2 • M0 •  

•   • T1 • N2 • M0 •  

•   • T2 • N2 • M0 •  

•   • T3 • N1, N2 • M0 •  

• (Stage IIIB) • T4 • Any N • M0 •  

•   • Any T • N3 • M0 •  

• Stage IV • Any T • Any N • M1 • Overall 10%

Penyebab

• Belum sepenuhnya diketahui• Faktor keturunan• Faktor resiko• Faktor lingkungan

Faktor keturunan

• 5-10 % Ca mamae diturunkan dr keluarga

• ♀<45 thn keturunan

Inherited Genes

• BRCA1 (Breast Cancer 1) • BRCA2 (Breast Cancer 2) • TP53 gene • ATM gene

BRCA 1 and BRCA 2

• Mutasi dari gen peningkatan kemungkinan terkena Ca mammae dr 10% mjd 80%

• Mutasi dari BRCA1 dan 2 40-50% kasus dari Ca mammae dari fk keturunan

• Dapat diturunkan dari ibu atau ayah

Gen TP53• Kode untuk tumor

suppressor protein p53.• Mutasi early onset

ATM• 1 defek kopi dengan 1

normal gen ini me↑ resiko Ca mamae

Faktor ResikoFk resiko yang tidak dapat dihindari:

• Gender• Aging• Genetic Risk Factors

(inherited)• Family History• Personal History• Race• Menstrual Cycle• Estrogen

Gaya Hidup• Oral Contraceptive Use• Not Having Children• Hormone Replacement

Therapy• Not Breast Feeding• Alcohol Use• Obesity• High Fat Diets• Physical Inactivity• Smoking

Faktor lingkungan

• Exposure to Estrogen• Radiation• Electromagnetic Fields• Exposure to Chemicals

Tumor marker pada Ca Mammae

• MUC-1 family: CA 15.3, MCA, CA 549, CA 27.29, CAM 26, CAM 29

• CEA• Oncoproteins (C-erbB-2)• Glycolitic enzymes: LDH• Milk proteins: lactoalbumin• Cytokeratins: TPA

• MUC-1: paling sering digunakan, mempunyai sensitivitas dan spesifisitas yang sama

• Penggunaan MUC-1 >1 ≠untuk menegakkan diagnosis

• CEA sbg TM tambahan utk menegakkan diagnosis

• 1MUC-1 antigen dengan CEA

TUMOR MARKERS IN LOCALIZED BREAST CANCER

• Tumor Marker determination may complement patient staging:

CA 15.3 and CEA are related to tumor burden, with ,significantly higher values in node positive patients and in patients with larger tumors.

• Preoperatively CA 15.3 or CEA ↑↑ are

associated with adverse outcome• Most study: preoperative CA 15.3 or CEA

independent prognostic factor

Early detection of metastases

• Increases in CA15.3 provide the first indication of recurrence, prior to clinical or radiological indication, in 40-55% of patients.

• Additional CEA measurements can increase the sensitivity in the early detection of recurrence obtained with CA 15.3 by up to 5-25% ,Lead Time 2-18 months (mean 5.2 month)

• Specificity for the detection of recurrence related to the cut-point used:

CEA > 5 ng/ml : 5% of false (+)results

CA 15.3 > 35 U/ml: 6,5% of false (+)results• Using higher cut-off values (CA 15.3=60

U/ml, CEA=10 ng/ml) and at least two serial increases (>15%), specificity increased to almost 100%.

Distant Metastase

• Combination of several markers (CA15.3, CEA, increase the sensitivity to 90% in patients with distant metastases.

• Tumor marker sensitivity is related to the site of metastases

THERAPY MONITORING

• The most important clinical application: Monitoring therapy response

• Patients in remission usually have↓↓marker levels, while those with progressive disease generally have ↑↑levels.

• Tumor markers should be measured prior to every chemotherapy course and at least three monthly for patients receiving hormone therapy

• An increase in tumor marker concentration of at least 25% of the previous value, with the second value above the reference interval, recommending that such an increase be confirmed in a second specimen obtained within a month

• If the continued increase is confirmed, this provides evidence of progressive disease.

• confirmed decreases in serum levels of more than 50% are consistent with tumor response.