Cancer Part 1

Cancer part 1

Cancer Good news • Death rate declining for some cancers. • We know a lot more about cancers than ever before. • Cancer has less social impact cf other diseases.

Bad news • There are a lot more cancers around because they are diseases of aging. • We know how to prevent some cancers but do not apply that knowledge. • There is a cancer lobby.

Current views on causes of death from “Cancer USA”: Diet Smoking Infections Work chemicals Alcohol excess Sunlight Pollution Medical and drugs Sexual promiscuity Unknown

35% 30% 10% 4% 3% 3% 2% 1% 1% 11%

Cancer in Canada 2004 (NCIC) Men

Dead

Women

Dead

Lung

10,700

Lung

8,200

Colorectal

4,500

Breast

5,200

Prostate

4,200

Colorectal

3,900

Pancreas

1,600

Pancreas

1,700

NHL

1,550

Ovary

1,550

Cancers cases in Canada Lung Breast Prostate Colon Lymphoma (NHL) Kidney (renal cell) No known primary Pancreas Leukaemia Thyroid

22,200 new/year 21,800 20,500 19,000 6,500 4,500 3,500 3,400 3,200 3,100

Cancer in people 20-44 years

Cancer is: • • • •

Uncontrolled growth of Abnormal cells to form Malignant tumour which may Metastasize.

Cancer symptoms • • • • • •

Weight loss Change in bowel habit General malaise Lumps Family history. etc

Opinions on current state of knowledge of cancer (MOH) • • • • • •

Cancer occurs at same rate as in 1900. Cancer survival is about the same as in 1900. Type of cancer seen has changed since 1900. More lifestyle and occupational cancers now. Some treatments work well on some cancers. Cancer is a disease of aging.

Laboratory cancer marker problem Trying to guess what is going on inside the cell from what is in the fluids outside of it.

Current tumour markers are: • Made by cancer cells or in response to them • In an accessible fluid • Different from health • Detectable by an analytically sound method • Detected before metastasis (hopefully)

Tumour markers are “visible” on death of cell and/or transport out of cell • The marker must cross basement membrane to enter blood circulation. • This may take metastasis • In blood stream get : Dilution, Metabolism, Excretion.

Tumour markers are used in: • Evaluation of risk/prevention. I (But is early diagnosis useful?) • Differential diagnosis • Prognosis, staging of disease • Amount of tumour • Detection of metastasis. • Showing response to treatment

Types of tumour markers in use: Those made by the cancer: • Oncofetal antigens • Hormones • Monoclonal proteins • Enzymes • Cell surface antigens. Those made by the body against cancer: • Anti inflammatory markers

Also there are non specific chemistry changes in cancer:

Cancer markers: oncofetal antigens • • • • •

CEA = colorectal + AFP = liver + hCG = germ cells + CA 125 = ovarian + CA 19.9, CA 24-25, CA 27-29 = breast cancer • Placental like ALP = seminomas +

Carcinoembryonic antigen • Developed in Montreal by Dr Gold • Claimed to be specific marker for colon cancer but is not • Found in lung, breast, ovarian cancers. Smokers, inflammatory bowel disease, liver disease.