বুধবার, ২৯ ফেব্রুয়ারী, ২০১২

USMLE ? Prostate Cancer | USMLE Step 1, Step 2 CK, Step 3 ...

Pathophysiology
1. Neoplastic transformation of prostate glands
2. Tumors almost always occur peripherally in gland (as opposed to more central and periurethral enlargement in benigh prostatic hyperplasia
3. Capsular invasion is common
4. Metastases go to obturator node, then iliac and periaortic nodes
5. Blood-borne metastases occur via the venous plexus to the vertebra, ribs, and pelvic bones and occasionally to lungs and liver

Signs and Symptoms
1. With screening programs (serum PSA and digital rectal exam), cancers, can be detected when asymptomatic
2. On digital exam, tumor is hard, nodular, and irregular
3. Bone pain in metastatic disease
4. Scrotal edema and limb edema in advanced local disease
5. Bladder outlet obstruction symptoms in very advanced local disease

Characteristic Test Findings
1. Increased serum PSA
2. Increased prostatic acid phosphatase
3. Increased urinary estrone/testosterone levels

Histology/Gross Pathology
1. Precancerous lesion found is prostatic intraepithelial neoplasia (not hyperplastic nodules)
2. Tumors are almost always adenocarcinoma and take an acinar glandular morphology (the more acinar glandular the better differentiated)
3. Gleason score is used to grade the tumor on the major and minor patterns of tumor gland formation ? best score is 2 (or 1+1), and worse score is 10 (or 5 + 5)
4. Tumors are multicentric and located peripherally in gland, causing early capsular invasion

Associated Conditions
Possibly linked to high-fat diet

Biochemistry
Associated with markers ? 1) alpha-TGF 2 2) type 4 collagen 3) expression of bcl-2 and c-erb-2 oncogenes

Inheritance/Epidemiology
1. Most common occurring cancer in men in USA
2. Causes 30,000 deaths/year
3. Affects men mostly over 60 years of age
4. In USA most prevalent in American blacks
5. 10% of cases are familial and have onset at age 50-60

Treatment
1. Several options exist and treatment protocols are evolving
2. Radical prostatectomy in earlier age groups and stage 1 and 2 disease
3. Older patients in stage 1 and 2 sometimes elect for radiation treatment (either external beam or radiation seeds planted into prostate)
4. If metastatic ? hormonal manipulation is the major weapon (antagonists of LHRH to cause testosterone deprivation, orchiectomy, tamoxifen)

Tips for USMLE Step 1, Step 2 CK and Step 3
1. PSA is a screening test only ? over half of men with significantly elevated levels do not have adenocarcinoma and not all tumors have an increased PSA
2. PSA can be elevated in prostatitis and benign prostatic hyperplasia

Source: https://www.score95.com/blog/blog/usmle-prostate-cancer/

dark energy sherri shepherd sherri shepherd sean avery east river east river harry shum jr

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