Wednesday, July 23, 2008

Update on Prostate Cancer

Prostate cancer is now the second leading cause of cancer death in men and the incidence and mortality from this disease are rising. Furthermore, there is a downward rend in the age of diagnosis. Much of these trends are attributable to increased PSA testing.

Issues related to therapy

  • Side effects of surgery are incontinence and impotence There is some decrease in impotence with nerve sparing procedure which can be performed on selected patients.There are newer surgical techniques being investigated including cryosurgery.
  • Side effects of irradiation are often GI, including diarrhea and proctitis. Also acute and chronic cystitis. "Scarring" of the pelvis increases the difficulty of performing future surgeries should these be necessary. Impotence is a late complication in less than half the patients. Some centers use implants (brachytherapy). There is a very high local relapse rate after radiation therapy if biopsy is performed, but the clinical significance of positive biopsies is not always clear.
  • There is no evidence that neoadjuvant hormonal therapy (LHRH analog predominantly) can increase survival in patients undergoing curative radiotherapy.
  • Are there patients with palpable localized disease who don't need therapy? Scandinavian studies in well-differentiated patients suggest that not all patients need therapy.

Stage specific therapy

  • Stage A1 - observation mostly, although some might advocate surgery
  • Stages A2-B2 - the superiority of surgery or radiation has not been resolved.
  • Stage A3- this stage represents the largest group of patients (no palpable disease, biopsied on the basis of PSA) treatment is not clear, but at least 30 percent of these patients have extensive disease.
  • Stage C - often irradiated, although the appropriate therapy has not been determined.
  • stage D1 - hormonal therapy or wait till symptomatic
  • stage D2 -hormonal therapy

Screening for prostate cancer

When should screening start?
The ACS recommends that physicians should discuss PSA screening with their patients over age 50 and with a projected life expectancy of 10 years or more. In this discussion the morbidity of treatments for prostate cancer should be addressed. African Americans or those with a family history, should start screening start at 40. The question of whether screening saves lives is still not resolved, but is the subject of an ongoing NCI sponsered trial.

Interpret action of PSAs
  • prostatic index - keyed to size of the gland
  • age specific PSA - PSA normally increases with age, therefore a level of 4 has a different meaning in a 40 compared to 70 year old man.
  • free vs. bound PSA

Use of PSA with DRE and ultrasound (ultrasound is often performed to guide transrectal needle biopsy.

Stages and Grade of Prostate Cancer

Stage A. Non-palpable disease
1.) A1 - local carcinoma found incidentally during TUR
2.) A2 - diffuse involvement of the gland, often multifocal
3.) A3 - a new category, disease detected by PSA screening only. This is by far the biggest category of disease at presentation.

Stage B. Palpable tumor confined to the prostate
1.) B1 - confined to a single lobe and <1.5 style="font-weight: bold;">Stage C. Extracapsular invasion
1.) Cl - extracapsular involvement confined to the periprostatic tissue
2.) C2 - extracapsular involvement of seminal vesicles, bladder, rectum, or pelvic wall

Stage D. Metastatic disease
1.) D1 - disease involving regional lymph nodes (below bifurcation of the aorta)
2.) D2 - more extensive disease, usually bone metastasis

Grade: The Gleasons grading system: sum of the grade of the predominant and less well represented regions of the tumor. This has been a fairly good predictor of nodal invovement and prognosis.