Effect of obesity on overall survival following permanent prostate brachytherapy

15576

Background: To evaluate the impact of obesity on cause-specific (CSS), biochemical progression-free (bPFS) and overall survival (OS) following prostate brachytherapy. Methods: From April 1995 through March 2003, 1,093 consecutive patients underwent brachytherapy for clinical T1b-T3a (2002 AJCC) prostate cancer. The median follow up was 5.6 years. All patients were implanted at least 3 years prior to analysis. Evaluated body mass index (BMI) subgroups were < 25 (n=258), 25.0 to 29.9 (n=547), 30.0 to 34.9 (n=214) and = 35 (n=74) kg/m2, respectively. Four-hundred and thirty (39.9%) and 589 (53.9%) of the patients received androgen deprivation therapy or supplemental external beam radiation therapy, respectively. Multiple clinical, treatment and dosimetric parameters were evaluated as predictors of CSS, bPFS and OS. Results: The 11 year CSS, bPFS and OS for the entire cohort were 97.5%, 95.6% and 77.6% respectively. BMI did not impact CSS or bPFS for any of the BMI cohorts. However, OS was statistically lower in patients with a BMI < 25 kg/m2 (p = 0.014). A Cox linear regression analysis demonstrated that Gleason score was the best predictor of CSS while percent-positive biopsies, risk group,V100 and hypertension predicted for bPFS. Patient age and tobacco use were the strongest predictors of OS. One-hundred and twenty-eight patients have died with 108 (84.4%) of the deaths the result of cardiovascular/pulmonary disease (73) and second malignancies (35). To date, 12 patients have died of metastatic prostate cancer. Conclusions: Following brachytherapy, obesity did not impact CSS, bPFS or OS. Cardiovascular or pulmonary disease and second malignancies substantially outweighed prostate cancer as competing causes of death.

No significant financial relationships to disclose.

The impact of primary Gleason pattern on survival following brachytherapy for Gleason score 7 prostate cancer

15588

Background: A recent radical prostatectomy series reported lower rates of biochemical control and cause-specific survival in Gleason score 7 patients with primary Gleason pattern 4. In this study, we evaluated the impact of Gleason 4+3 versus 3+4 on cause-specific, biochemical progression-free and overall survival in patients managed with permanent prostate brachytherapy. Methods: From April 1995 to June 2003, 530 prostate cancer patients underwent brachytherapy for clinical stage T1b-T3c (2002 AJCC) prostate cancer with Gleason score 3+4 (n=300) or Gleason score 4+3 (n=230) histology. All patients underwent brachytherapy more than three years prior to analysis. The mean and median follow-up was 6.0 and 5.7 years, respectively (range 3.2–11.2 years). Of the evaluated cohort, 412 (77.7%) received supplemental XRT and 177 (33.4%) received androgen deprivation therapy. No statistical differences were discerned between the use of XRT, however, Gleason 4+3 patients were more likely (37.4% versus 30.3%, p=0.002) to receive ADT. Multiple clinical, treatment and dosimetric parameters were evaluated as predictors of cause-specific, biochemical progression-free and overall survival. Results: At 10 years, primary Gleason 3+4 versus 4+3 did not predict for cause-specific survival (96.7% versus 93.3%, p=0.506), biochemical progression-free (97.0 versus 92.9%, p=0.085) or overall survival (77.0% versus 78.0%, p=0.9333). Cox linear regression analysis demonstrated no significant predictors for cause-specific survival while pre-treatment PSA, prostate volume and clinical stage predicted for biochemical progression-free survival. Patient age, tobacco use and diabetes were the strongest predictor for overall survival. To date, 57 patients have died (25 with Gleason 4+3 and 32 with Gleason 3+4). Of the deaths, 76% were due to cardiovascular events or second malignancies. To date, 4 patients (2 in each cohort) have died of metastatic prostate cancer. Conclusions: Following brachytherapy, the primary Gleason pattern did not impact cause-specific, biochemical progression-free or overall survival in Gleason score 7 prostate cancer. Cardiovascular disease and second malignancies were responsible for 9 times more deaths than prostate cancer.

No significant financial relationships to disclose.

Androgen deprivation therapy does not impact cause-specific or overall survival in high-risk prostate cancer treated with brachytherapy and supplemental external beam

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Background: To determine cause-specific (CSS), biochemical progression-free (bPFS) and overall survival (OS) in high risk prostate cancer patients undergoing brachytherapy with or without supplemental therapies. Methods: From April 1995 through July 2002, 204 patients with high risk prostate cancer (Gleason score = 8 and/or PSA > 20 ng/mL and/or clinical stage = T2c) underwent brachytherapy with or without supplemental therapies. Of the 204 patients, 193 (94.6%) received supplemental XRT and 119 (58.3%) received ADT (ADT = 6 months n=40 and ADT > 6 months n = 79). Median follow-up was 7.0 years. All patients were implanted at least 4 years prior to analysis. BPFS was defined by a PSA = 0.40 ng/mL after nadir. Multiple clinical, treatment and dosimetric parameters were evaluated for the impact on survival. Results: The ten-year CSS, bPFS and OS were 88.9%, 86.6% and 68.6%, respectively. A statistically significant difference in bPFS was discerned between hormone naïve, ADT = 6 months and ADT > 6 month cohorts (79.7% vs. 95.0% vs. 89.9%, p= 0.032). ADT did not impact CSS (94.0% vs. 87.1%, p=0.983 ) or OS (65.2% vs. 70.3%, p = 0.713). For bPFS patients, the median post-treatment PSA was < 0.04 ng/mL. A Cox linear regression analysis demonstrated that Gleason score was the best predictor of CSS while percent positive biopsies and duration of ADT best predicted for bPFS. OS was best predicted by Gleason score and diabetes. Thirty-eight patients have died with 26 of the deaths due to cardiovascular/pulmonary disease or second malignancy. Eleven patients have died of metastatic prostate cancer. Conclusions: Androgen deprivation therapy improved 10-year bPFS without statistical impact on CSS or OS. Death as a result of cardiovascular/pulmonary disease and second malignancies were more than twice as common as prostate cancer deaths. Strategies to improve cardiovascular health should positively impact overall survival.

No significant financial relationships to disclose.

Prostate cancer distribution in patients diagnosed by transperineal template-guided saturation biopsy: Implications for brachytherapy treatment planning

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Background: Prostate cancer remains undetected in approximately one-third of patients following standard transrectal ultrasound-guided biopsy. In this study, we evaluated prostate cancer incidence, anatomic distribution, Gleason score profile and tumor burden in patients diagnosed by transperineal template-guided saturation biopsy (TTSB). Methods: One hundred and seventeen patients underwent TTSB. TTSB was performed under general anesthesia. All but one patient had undergone at least one prior negative TRUS biopsy. Criteria for inclusion included an elevated PSA and/or the diagnosis of ASAP or high-grade PIN on prior biopsy. The prostate gland was divided into 24 regional biopsy locations with 1–3 biopsies per region. The median number of biopsy cores was 50. Multiple clinical parameters were evaluated as predictors for prostate cancer diagnosis. Results: The mean patient age was 64.8 years with a mean PSA of 9.1 ng/mL and a prostate volume of 78.6 cm3. On average, patients had undergone 2.1 prior negative TRUS biopsies with a mean of 22.4 core biopsies. Prostate cancer was diagnosed in 49 patients (41.9%) with a Gleason score distribution of 6–9. Patients with a prostate volume of = 60 cm3 had a higher rate of cancer diagnosis compared to patients with larger glands (66% vs. 30%). Although no anatomic region of the prostate gland was spared of cancer, there was a preponderance of anterior-based malignancies. In patients with prostate cancer, an average of 9.9 cores were involved. In multivariate analysis, pre-saturation biopsy diagnosis and prostate volume were the best predictors for prostate cancer diagnosis. Conclusions: Transperineal template-guided saturation biopsy diagnosed prostate cancer in 41.9% of previously biopsied patients. Considerable anatomic variability in prostate cancer distribution was documented. Based on this and other reports, cancer eradication will be dependent on treatment of the entire prostate gland.

No significant financial relationships to disclose.

Does hormonal manipulation in conjunction with permanent interstitial brachytherapy, with or without supplemental external beam irradiation, improve the biochemical outcome for men with intermediate or high-risk prostate cancer?

OBJECTIVE

To determine whether hormonal manipulation improves the biochemical outcome for men with intermediate or high-risk prostate cancer and undergoing permanent brachytherapy with or without supplemental external beam radiation therapy.

PATIENTS AND METHODS

From April 1995 to August 2000, 350 patients with intermediate-risk (225 men; a Gleason score of >or= 7 or a prostate specific antigen, PSA, level of >or= 10 ng/mL or clinical stage >or= T2b) or high-risk features (125 men; two or three of a Gleason score of >or= 7 or PSA >or= 10 ng/mL or clinical stage >or= T2b) underwent transperineal ultrasonography-guided permanent brachytherapy. No patient underwent pathological lymph node staging. Of these patients, 293 received supplemental external beam radiation therapy (EBRT), 141 received hormonal manipulation, with 82 having hormonal therapy for <or= 4 months (median 4) for cytoreduction, while 59 had neoadjuvant and adjuvant hormonal manipulation (median 8 and 12 months for intermediate- and high-risk, respectively). The median patient age was 68.5 years. No patient was lost to follow-up. The mean (sd) and median follow-up was 50 (18) and 49 months (calculated from the day of implantation). Biochemical disease-free (BDF) survival was defined using a consensus definition. The clinical variables evaluated for BDF survival included risk group, Gleason score, patient age, clinical T-stage and pretreatment PSA. Treatment variables included use of hormonal manipulation stratified into cytoreductive (<or= 4 months) vs adjuvant (> 4 months) regimens, supplemental EBRT, isotope and dosimetric variables.

RESULTS

For intermediate-risk patients, the 6-year actuarial BDF survival rates were 98%, 96% and 100% for hormone naïve, cytoreductive and adjuvant treatment, respectively (P = 0.693); for high-risk patients the respective values were 79%, 94% and 92% (P = 0.046). When stratified by pretreatment PSA, hormonal manipulation improved the outcome for patients with a PSA of >or= 10 ng/mL (P = 0.019), but not for those with < 10 ng/mL (P = 0.661). Hormonal status was not statistically significant in predicting biochemical outcome when stratified by Gleason score. The follow-up in hormone-naïve patients was significantly longer than that in hormonally manipulated patients, at 55 (20) vs 43 (15) months (P < 0.001). In a multivariate analysis only the Gleason score predicted failure in intermediate-risk patients, while pretreatment PSA, the use of hormonal manipulation and Gleason score predicted the outcome in high-risk patients (P = 0.035). For both hormone-naïve and hormonally manipulated BDF patients, the median PSA level after implantation was < 0.1 ng/mL.

CONCLUSION

In patients treated by permanent prostate brachytherapy, hormonal manipulation improved the biochemical outcome for those at high-risk and those with an initial PSA of >or= 10 ng/mL, but not for those with intermediate-risk features. The use of hormonal therapy for> 4 months conferred no additional biochemical advantage over short-course regimens. Because the follow-up in hormone-naïve patients was longer than that for those receiving hormonal manipulation, additional follow-up will be mandatory to confirm the durability of these findings.

Perineural invasion is not predictive of biochemical outcome following prostate brachytherapy

PURPOSE

The purpose of this article is to evaluate whether the presence of perineural invasion (PNI) in the biopsy specimen is predictive of 5-year biochemical disease-free outcome after prostate brachytherapy.

MATERIALS AND METHODS

Four hundred twenty-five patients underwent transperineal ultrasound-guided prostate brachytherapy using either 103Pd or 125I for clinical T1b/T3a NXMO (1997 American Joint Committee on Cancer) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up, and no patient underwent pathological lymph node staging. Two hundred twenty-one patients were implanted with 103Pd, and 204 patients were implanted with 125I. Of this cohort, 190 patients were implanted without supplemental beam radiation, and 235 received moderate-dose external-beam radiation therapy followed by a prostate brachytherapy boost. One hundred sixty-three patients received hormonal manipulation in conjunction with the brachytherapy implant (86 of these patients received moderate-dose external-beam radiation therapy before brachytherapy), and 262 patients were hormone naïve. Perineural invasion, defined as carcinoma tracking along or around a nerve within the perineural space, was identified in 105 patients (24.7% of the population). The median patient age was 68 years (range, 48-81 years). The mean follow-up was 37.1 +/- 15.2 months, and the median follow-up was 35.4 months (range, 6-74 months). Follow-up was calculated from the date of implantation. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology (ASTRO) consensus definition.

RESULTS

When Kaplan-Meier survival analysis was performed, the presence of PNI did not predict failure. When PNI was entered into a Cox regression analysis with evaluated clinical predictors of failure (age, clinical T stage, pretreatment prostate-specific antigen level, and Gleason score) or treatment parameters (use of neoadjuvant hormonal therapy, supplemental external-beam radiation therapy, and choice of isotope), PNI did not add to the predictive strength of these variables. The median disease-free prostate-specific antigen level was 0.1 ng/mL for the entire cohort.

CONCLUSIONS

Our results indicate that actuarial 5-year biochemical outcomes with a prostate brachytherapy approach that utilizes generous periprostatic margins is not dependent on the presence of PNI. In addition, PNI should not be used as an independent prognosticator in determining the need for combined-modality therapy in patients undergoing prostate brachytherapy.