Low-dose-rate prostate brachytherapy: 4-8 week postimplant prostate-specific antigen a novel predictor of biochemical failure-free survival

Brachytherapy for favorable prognostic prostate cancer in men up to 60 years of age: Long term follow-up

PURPOSE

Brachytherapy (BT) is a standard treatment for low- and favorable intermediate-risk prostate adenocarcinoma. Few studies have focused on young patients. We therefore evaluated long-term efficacy and toxicity of BT in patients aged ≤ 60 years with low- and favorable intermediate-risk prostate cancer.

MATERIALS AND METHODS

This retrospective study included patients aged ≤60 years with low- or favorable intermediate-risk prostate adenocarcinoma treated with iodine BT alone between 1999 and 2014 at the Institut de Cancérologie de Lorraine. Follow-up assessment included incidence of biochemical failure (BF) at 10 and 15 years after BT, as well as survival data and late toxicities.

RESULTS

A total of 177 patients of median age 56 years (54-58) were analyzed, with a median follow-up of 126 months (97-172). Incidence of BF at 10 and 15 years after BT was 5.4% and 11.7% respectively. PSA nadir (HR = 51.8 [95% CI 6.69-277], p < 0.001), age at treatment (HR = 1.78 [95% CI 1.19-2.65], p = 0.005) and prostate D90% (HR = 1.08 [95% CI 1.01-1.15], p < 0.021) were identified as predictive factors of BF. Overall survival at 10 and 15 years after BT was 92.8% and 84.4% respectively. Cancer-specific survival at 10 and 15 years after BT was 99.3% and 97.7% respectively. No major toxicity was recorded.

CONCLUSIONS

Exclusive BT is a long-term effective treatment for patients aged ≤ 60 years with low- or favorable intermediate-risk prostate adenocarcinoma.

Biochemical outcomes and toxicities in young men with prostate cancer after permanent iodine-125 seed implantation: Prospective cohort study in 6662 patients

PURPOSE

We evaluated the effect of age, <60 and ≥60 years, on biochemical outcomes and toxicities in patients with prostate cancer who underwent permanent seed implantation (PI) ± external beam radiation therapy ± hormone therapy in a national Japanese prospective cohort study (J-POPS).

METHODS AND MATERIALS

The safety and efficacy analyses included 6721 and 6662 patients, respectively. We categorized patients into two age groups: <60 (n = 716) and ≥60 (n = 6,005) years. We used propensity score matching (PSM) to estimate the marginal effect of age on biochemical freedom from failure (bFFF) using a Phoenix definition and Cox proportional hazard models.

RESULTS

The median followup period was 60.0 months. Without PSM, men <60 years demonstrated similar 5-year bFFF (96.3%) compared with men ≥60 years (95.6%; p = 0.576); percent positive biopsies, biologically effective dose, Gleason score, risk classification, and supplemental external beam radiation therapy (p <0.001, <0.001, <0.001, 0.008, and <0.001) were significantly associated with bFFF while age was not (p = 0.576). With PSM, bFFF was not significantly different between age groups (p = 0.664); however, men <60 years showed a significantly lower incidence of declining erectile function, grade ≥2 all urinary toxicities, urinary frequency/urgency, and rectal bleeding (p <0.001, 0.024, 0.031, and 0.010) than men ≥60 years.

CONCLUSIONS

After PI, men <60 years achieved a comparable 5-year biochemical control rate and showed a lower incidence of several toxicities compared to men ≥60 years. This suggests that PI should be an excellent treatment option for men <60 years with prostate cancer.

Biochemical outcomes and predictive factors by risk group after permanent iodine-125 seed implantation: Prospective cohort study in 2,316 patients

PURPOSE

To evaluate the biochemical freedom from failure (bFFF) by risk group and treatment modality and the predictive factors of bFFF by risk group in patients with prostate cancer undergoing permanent seed implantation (PI) with or without external beam radiation therapy (EBRT) in a nationwide prospective cohort study (Japanese Prostate Cancer Outcome Study of Permanent Iodine-125 [I-125] Seed Implantation) in Japan during the first 2 years.

METHODS AND MATERIALS

The analyses included 2,316 participants in 42 institutions; bFFF was evaluated using the Phoenix definition and calculated using the Kaplan-Meier method, and the Cox proportional hazards model was used to identify the factors associated with bFFF.

RESULTS

Median followup period was 60.0 months. The 5-year bFFF rates in all patients, 1,028 low-risk patients, 1,114 intermediate-risk patients, and 133 high-risk patients were 93.6%, 94.9%, 92.7%, and 91.1%, respectively. The 5-year bFFF rates in the PI group and EBRT combination therapy group were 93.7% and 93.3%, respectively. In a multivariate analysis, younger age, higher Gleason score (GS), higher percent positive biopsies (%PB), and lower prostate V₁₀₀ (p = 0.0012, 0.0030, 0.0026, and 0.0368) in all patients; younger age, higher pretreatment prostate-specific antigen, and lower prostate V₁₀₀ (p = 0.0002, 0.0048, and 0.0012) in low-risk patients; higher GS, higher %PB, and no hormonal treatment (p = 0.0005, 0.0120, and 0.0022) in intermediate-risk patients; and higher GS and higher %PB (p = 0.0329 and 0.0120) in high-risk patients were significantly associated with bFFF.

CONCLUSIONS

PI with or without EBRT resulted in excellent short-term biochemical outcomes in all risk groups, especially in high-risk patients. Age, pretreatment prostate-specific antigen, and prostate V₁₀₀ in low-risk patients; GS, %PB, and hormonal treatment in intermediate-risk patients; and GS and %PB in high-risk patients were independently affected bFFF.