EFFICACY OF DIGITAL RECTAL EXAMINATION AFTER RADIOTHERAPY FOR PROSTATE CANCER:

Recurrent prostate cancer following external beam radiotherapy

All patients who undergo curative therapy for prostate cancer should be followed for a prolonged period of time to determine tumor control and treatment toxicity for quality assurance purposes. Follow-up duties may be reasonably shared between the oncologist and the family doctor or urologist: however, it is probable that some follow-up information specific to the irradiated patient will be lost unless the oncologist maintains regular contact with the patient, especially in the first 5 years of follow-up when late radiation effects are most likely to appear. There is no strong evidence that patients stop being at risk for recurrence at any time after treatment, and because PSA testing is an accurate, simple, and inexpensive method of determining post-RT tumor status, it is recommended that periodic PSA measurements be continued for life. In the absence of a rising PSA, all other tests and visits are unnecessary to determine post-RT tumor control. Because DRE has been shown to be of limited utility in follow-up of irradiated patients, it should be possible to effectively follow patients remotely. This could be done by asking patients to have PSA tests done, forward the results to their physicians, and report treatment toxicity when it occurs. Only abnormal results would trigger an office visit. This strategy is being evaluated in clinical trials. The alternative is to delegate the follow-up to the primary-care physician with guidelines as to when referral back is required. Follow-up frequency, and the most beneficial follow-up investigations vary from scenario to scenario, and are influenced by the likelihood of relapse, time to relapse, and planned intervention. These decisions are influenced in turn by the initial presentation--either with high or low risk factors--and by the patient's general state of health at completion of EBRT. Effective follow-up also requires active patient cooperation that only can be achieved after discussion of the goals of follow-up with the patient and with the patient's full understanding of the process. The follow-up strategy proposed in Fig. 1 is most suitable for a fit patient with low or intermediate risk factors who wishes to consider all salvage options should he relapse, or for the high-risk individual in situations in which the probability of systemic relapse is of major concern. Young patients with very adverse risk factors may benefit from even closer follow-up in the early years after EBRT and the elderly or frail may require only occasional visits to record or treat treatment toxicity and to ensure clinical non-progression.

[Clinical and biological surveillance after radiotherapy for localized prostate cancer]

Serum PSA is an excellent marker of disease status after external beam radiotherapy or brachytherapy for patients with prostate carcinoma. A low PSA nadir < or = 1 even < or = 0.5 ng/mL has been shown to be as a surrogate end point for disease control. Three successive increases of this marker after achieving the nadir defines recurrence as recommended by the American Society for Therapeutic Radiology and Oncology. The biochemical relapse or PSA failure after treatment precedes clinical disease relapse by several months. PSA profile or kinetics may have implications for patterns of failure and prognosis. Prostate post-radiotherapy biopsies should not be part of routine follow-up as its interpretation is frequently problematic. Other exams should not be performed unless clinical symptoms are present. Post-radiotherapy relapse treatment has generally no curative intent.