Note: Some citations in the text of this section are followed by a level of evidence. The PDQ editorial boards use a formal ranking system to help the reader judge the strength of evidence linked to the reported results of a therapeutic strategy. (Refer to the PDQ summary on Levels of Evidence for more information.)
Stage III prostate cancer is defined by the American Joint Committee on Cancer's TNM classification system:
Like other forms of cancer, the prognosis for prostate cancer depends on how far the cancer has spread at the time it’s diagnosed. Doctors use a system of classification called staging to describe prostate cancer’s local extent and evidence of spread.
Prostate cancer stages can be complex and difficult to understand. WebMD takes a look at prostate cancer stages and what they mean to you.
T3a-b, N0, M0, any prostate-specific antigen (PSA), any Gleason.
Extraprostatic invasion with microscopic bladder neck invasion (T4) is included with T3a.
External-beam radiation therapy (EBRT), interstitial implantation of radioisotopes, and radical prostatectomy are used. The results of radical prostatectomy in stage III patients are greatly inferior compared with results in patients with stage II cancer. Interstitial implantation of radioisotopes is technically difficult in large tumors. EBRT using a linear accelerator is the most appropriate treatment for most patients with stage III prostate cancer, and large series support its success in achieving local disease control and disease-free survival (DFS).[3,4] Prognosis is greatly affected by whether regional lymph nodes are evaluated and proven not to be involved. The patient's symptoms related to cancer, age, and coexisting medical illnesses should be taken into account before deciding on a therapeutic plan. In a series of 372 patients treated with radiation therapy and followed for 20 years, 47% eventually died of prostate cancer, but 44% died of intercurrent illnesses without evidence of prostate cancer.
Hormonal therapy should be considered in conjunction with radiation therapy, especially in men who do not have underlying moderate or severe comorbidities.[5,6] Several studies have investigated its utility in patients with locally advanced disease. The Radiation Therapy Oncology Group (RTOG) performed a prospective, randomized trial (RTOG-8531) in patients with T3, N0, or any T, N1, M0 disease who received prostatic and pelvic radiation therapy and then were randomly assigned to receive immediate adjuvant goserelin or observation with administration of goserelin at time of relapse. In patients assigned to receive adjuvant goserelin, the drug was started during the last week of the radiation therapy course and was continued indefinitely or until signs of progression. The actuarial overall 10-year survival rate for the entire population of 945 analyzable patients was 49% on the adjuvant arm versus 39% on the observation arm P = .002. There was also an improved actuarial 10-year local failure rate (23% vs. 38%, P < .001).[Level of evidence: 1iiA]
A similar trial was performed by the European Organization for Research and Treatment of Cancer (EORTC). Patients with T1, T2 (World Health Organization grade 3), N0-NX or T3, T4, N0 disease were randomly assigned to receive either pelvic/prostate radiation therapy, or identical radiation therapy and adjuvant goserelin (with cyproterone acetate for 1 month) starting with radiation therapy and continuing for 3 years. The 401 patients available for analysis were followed for a median of 9.1 years. The Kaplan-Meier estimates of overall survival (OS) at 10 years were 58.1% on the adjuvant arm and 39.8% on the radiation alone arm (P = .0004). Similarly, 10-year DFS (47.7% vs. 22.7%, P < .0001) and local control (94.0% vs. 76.5%, P < .001) favored the adjuvant arm.[8,9][Levels of evidence: 1iiA,1iiDii] Two smaller studies, with 78 and 91 patients each, have also shown similar results.[10,11]