Cancer Part 3

Cancer part 3

Problem 4. cancer profiles or testing panels. to increased clinical sensitivity but ! • Gastrointestinal – CEA (GGT) • Testis – hCG, AFP, CEA • Prostate – PSA, ACP, Prolactin, FSH, LH, Testosterone, Androstenedione. (at SWH)

Problem 4. Cancer markers in test “profiles”: • Test A = 95% clin. sensitivity • Test B = 80% clin. sensitivity • Together = 99% clin. sensitivity But • Test A = 90% clin. specificity • Test B = 95% clin. specificity • Together = 85% clin. specificity Therefore: sensitivity increased, specificity decreased

Problems 5. Prevalence of cancer. • • • • • • •

USA NIH, new cases in the year 2001 All sites 0.46% Lung bronchus in men 0.10% Prostate 0.17% Breast 0.12% Colon and rectum in men 0.06% Ovary, stomach, pancreas 0.01%

Problem 5. Prevalence of cancer • % of non institutional patients who have ever been diagnosed with cancer = 6.6 • % of current patients in home care with cancer as the primary diagnosis = 5.0

Problems 6. laboratory use in chemotherapy treatments: • Measurement of chemotherapeutic agents : methotrexate, 5-Fluorouracil • Tests for functions of organs damaged by chemotherapy: Liver Test – ALT Renal Function Test – creatinine • Tumour necrosis syndrome: LD, uric acid, complete Blood Count.

Cisplatinum causing low s-Na:

Problem 7. Paraneoplastic syndrome • Develops in association with tumour. • Seen in 7-15% of patients, e.g.: Calcium abnormal, caused by PTH like protein. Electrolytes abnormal by ADH. Cortisol abnormal by ACTH. Hypoglycaemia by Insulin like Growth Factor. Gynecomastia by hCG. Extra pituitary acromegaly by growth hormone.

Paraneoplastic syndrome (continued) • Hormones, continued Polycythaemia by erythropoietin EPO Hypertension by renin. • Trace metals: Decreased: Zn, Fe Increased: Cu • Lipids: Decreased: cholesterol.

Problems with cancer markers 8 - genetic testing. • • • •

Assesses potential for cancer. Expensive to do. Patent issues. Quality control lacking. Proven familial cancers not common (5%?) • Impact of genetic testing on populations’ health is not yet clear.

Some familial cancers Syndrome

Cancers

Gene marker

Melanoma

Melanoma, pancr

MTS1/p16

Some breast / ovary Breast, ovary +

BRCA1

Hereditary breast

Breast +

BRCA 2

Hereditary non polyposis colon Li-Fraumeni

Colon, uterine, +

MSH2,MLH1P MS1,PMS2 p53

Brain,sarcoma+

Mult Endocrine Neo Medul thyroid +

RET

A cancer screening success • • • •

Human papilloma virus, some types cause Cervical and other genital cancers. Screening available now. At risk if early sexual activity and multiple partners. • Poor do not use the service.

Cancer: Cancer problems with diagnosis and treatment • Cancer is many diseases. • Is early cancer diagnosis a benefit? • Chemotherapy - how much is needed? – when does it work? – the long term effects. • Radiation and surgery – slash and burn. • Transplants – a solution to organ failure but “future shock” is increased rate of cancer.

Summary: laboratory cancer markers, continued • Limited use in screen for disease. • Useful in prognosis, monitoring disease. • Usually found too late for easily tolerated therapy. • Cancer understanding has been much improved. • Treatment is not much improved. • Prevention is best.

Coal miner’s lung