lawsuit surrounds the management op...

lawsuit surrounds the management options for localized prostate cancer--conservative management, prostatectomy, and radiation. Choosing among these options is difficult because of long-term side forces that include sexual, urinary, and bowel dysfunction. one recent studies suggest that patients who have chosen treatment (i.e., radical prostatectomy or radiation) have longer disease-free survival compared with patients who have chosen conservative management (i.e., watchful waiting). However, several biases may artificially enhance the perceived value of treatment and make the interpretation of studies upon treatment outcomes difficult. Sources of bias include lead time, fulness time, and patient selection. Because of the uncertain efficacy of management options and the risk of long-term treatment complications, family physicians ne to engage their patients in the decision-making proces (Am Fam Physician 2005;71:1915-22 1929-30 Copyright[C] 2005 American Academy of Family Physicians.)

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Although with prostateprostate cancer is a commonly diagnosed malignancy, its management remains controversial. The majority of patients cancer are older than 65 years (median age of diagnosis is 71 years for white American men and 69 years for black American men) (1) Approximately 220000 American men were diagnosed in 2003 yet because of the long natural history of prostate cancer, there were single 28,900 deaths in that year. (2) Conservative management, or watchful waiting, has been adviseed as an alternative to more aggressive therapies like as radical prostatectomy or radiation because many patients with prostate cancer will die from other causes (most commonly heart disease). Conservative management also may be favorable for older men with a life expectancy of les than 10 years because they are unlikely to benefit from, and perhaps les able to tolerate, aggressive interventions. (3)

novel studies (4-7) have suggested that patients with clinically localized prostate cancer have a longer disease-free survival following radical prostatectomy or radiation. Direct comparisons of treatment options with conservative management generally have favored treatment, partly because of cogitation design issues often found in observational prostate cancer studies: lead-time, length-time, and selection bias. With these biases in mind, this analysis discusses out-come and long-term side results associated with the primary management options for clinically localized prostate cancer, including external radiation and interstitial se radiation (or brachytherapy).

Sources of Bias LEAD-TIME BIAS

Screening generally find outs early disease in asymptomatic patients. Survival duration typically is calculated from the date that disease is diagnosed until death. Therefore, the interval between cancer detection and death is longer in guarded patients than in unscreened patients (Figure 1) Prostate-specific antigen (PSA) screening has shifted the diagnosis of prostate cancer toward clinically localized (i.e., T1 and T2) disease. (58) The lead time resulting from PSA screening has been estimated to be between three and five years. (9) Increased survival rates after treatment in the post-PSA era, when compared with the pre-PSA era, may be the ensue of earlier diagnosis and not necessarily early detection and treatment. A large randomized trial comparing treatment with conservative management for patients diagnosed on PSA screening has not been complet (10)

[FIGURE 1 OMITTED]

LENGTH-TIME BIAS

Diseases with lengthy preclinical phases are more likely to be find outed by screening (Figure 2). (11) For example, screening may not be able to find rapidly progressing disease because the window of opportunity to expose asymptomatic disease is small. Because of differences in tumor differentiation (Gleason score), prostate cancer tumors progres at different rates (Table 1) (12) A greater proportion of cancers diagnosed as a rise of PSA screening are moderately differentiated (i.e., Gleason score of 5 to 6) than are poorly differentiated. (58) It is not clear whether all patients with Gleason 5 to 6 cancer benefit from aggressive management. (13) Therefore, better disease-free survival rates after treatment in the post-PSA era may be the terminate of treatment for less aggressive tumors (length-time bias) and not necessarily because of early detection and treatment.

[FIGURE 2 OMITTED]

SELECTION BIAS

Observational studies may be biased because of patient selection. issues in patients from tertiary care institutions may not be directly comparable with those in patients from community settings. For example, urinary complication rates following surgery have been shown to be lower in high-volume hospitals. (14) Surgical studies serve to select only patients who have had a radical prostatectomy; patients with advanced disease generally are exclud because surgery frequently is stopped upon the discovery of extensive disease. (15) More importantly, surgically man-aged patients will have pathologic evaluation of resect tissue and pelvic lymph nodes. alone 40 to 60 percent of patients with clinically localized disease (T1 and T2) remain classified with localized disease because of capsular (T3) or nodal (T4) involvement. (45) Thus, patients with localized cancer based forward surgical staging (after radical prostatectomy) generally will have better consequences compared with patients with clinically localized cancer (during conservative management or after radiation) because patients with advanced disease have been exclud from the surgical cohort.