Young patients with prostate cancer have an outcome justifying their treatment with external beam radiation

Factors influencing prostate cancer patterns of care: An analysis of treatment variation using the SEER database

PURPOSE

The aim of this study is to describe the trends and factors that influence the initial treatment of men with localized prostate cancer (PC) in the United States between 2004 and 2014.

METHODS AND MATERIALS

The National Cancer Institute's Surveillance, Epidemiology and End Results database was used to identify patients with primary prostate adenocarcinoma between 2004 and 2014. Patients were staged in accordance with the American Joint Committee on Cancer 7th edition criteria and stratified according to the National Comprehensive Cancer Network guidelines risk group classification. Descriptive statistics describing treatment patterns by year of diagnosis, age, risk group, insurance status, and region were performed.

RESULTS

A total of 460,311 male patients were identified with sufficient information to be categorized into National Comprehensive Cancer Network risk groups. Overall, 30.9% of patients had low-risk disease, 38.1% were intermediate risk, 20.2% were high risk, 4.4% were very high risk, 1.6% were node-positive, and 4.7% had metastatic disease. During the study period, there was a 60% decrease in brachytherapy monotherapy utilization for patients with PC, and no definitive treatment increased from 20.3% in 2004 to 26.3% in 2014. There were regional treatment variations and discrepancies in treatment by age. Radical prostatectomy was performed on a greater proportion of insured patients than patients with Medicaid or those who were uninsured, but radiation therapy and no definitive treatment was administered to a greater proportion of uninsured and Medicaid patients.

CONCLUSIONS

PC treatment shows declining trends in brachytherapy utilization, increases in conservative management, and stability of surgical procedures over time. There is wide variation by geographical region, age, and insurance status.

Radiotherapy for early-stage prostate cancer in men under 70 years of age

AIMS

To demonstrate that radiotherapy (RT) is a valid alternative to surgery in men ≤70 years old with localized prostate cancer.

METHODS

From 1988 to 2009, 214 patients with T1-2 N0 M0 prostate cancer were treated with RT. The effects of patient- and treatment-related risk factors on toxicity were investigated.

RESULTS

Median follow-up was 105 months (range 14.2-180). The 5-, 10-, and 15-year biochemical relapse-free survival for all 214 patients was 80%, 61.9%, and 57.5%, respectively. In bivariate analysis, age (≤65 vs 65-70 years) was not a significant factor for biochemical relapse, while radiation dose was (p = 0.05) in multivariate analysis. Cancer-specific survival rates at 5, 10, and 15 years were 98.4%, 93.2%, and 69.7%, respectively. Median overall survival (OS) was 167 months (95% confidence interval 147.3-186.7). The OS rates at 5, 10, and 15 years were 91.8%, 75.8%, and 42.5%, respectively. Acute genitourinary (GU) and gastrointestinal (GI) toxicities occurred in 105 (49%) and 98 patients (45.8%), respectively, with only 2 cases of grade III GI toxicity. Late GU and GI toxicities occurred in 17 (7.9%) and 20 (9.3%) patients, respectively, with 1 grade III GI toxicity and 2 grade III GU toxicities. Risk factors for late toxicity were age and RT dose and technique, which were unrelated to acute toxicity.

CONCLUSIONS

Age ≤70 years does not consistently confer a negative prognosis for localized prostate cancer. Radiotherapy appears to be a viable alternative to surgery, offering excellent long-term cancer control.

Young age under 60 years is not a contraindication to treatment with definitive dose escalated radiotherapy for prostate cancer

BACKGROUND

It is widely believed that younger prostate cancer patients are at greater risk of recurrence following radiotherapy (RT).

METHODS

From 1992 to 2007, 2168 (395 age ≤ 60) men received conformal RT alone for prostate cancer at our institution (median dose=76 Gy, range: 72-80). Multivariable analysis (MVA) was used to identify significant predictors for BF and PCSM. Cumulative incidence was estimated using the competing risk method (Fine and Gray) for BF (Phoenix definition) and PCSM to account for the competing risk of death.

RESULTS

With a median follow-up of 72.2 months (range: 24.0-205.1), 8-year BF was 27.1% for age ≤ 60 vs. 23.7% for age >60 (p=0.29). Eight-year PCSM was 3.0% for age ≤ 60 vs. 2.0% for age >60 (p=0.52). MVA for BF identified initial PSA [adjusted HR=1.7 (PSA 10-20), 2.6 (PSA >20), p<0.01], Gleason score [adjusted HR=2.1 (G7), 1.9 (G8-10), p<0.01], T-stage [adjusted HR=1.7 (T2b-c), 2.6 (T3-4), p<0.01], and initial androgen deprivation therapy (ADT) [adjusted HR=0.38 (ADT >12 months), p<0.01] as significant, but not age or ADT <12 months. MVA for PCSM identified Gleason score [adjusted HR=3.0 (G8-10), p=0.01] and T-stage [adjusted HR=8.7 (T3-4), p<0.01] as significant, but not age, PSA, or ADT.

CONCLUSION

This is the largest, most mature study of younger men treated with RT for prostate cancer that confirms young age is not prognostic for BF.

Impact of patient age on biochemical recurrence rates following radical prostatectomy

PURPOSE

Increased age has been suggested to predict worse clinical outcomes in patients with prostate cancer. An explanation that was proposed for this observation is that it is due to inherent differences in the biological properties of prostate cancer in older men. Stage migration, prostate specific antigen and prostate biopsy pathology are variables that may confound the interpretation of age as an independent prognosticator of outcomes following radical prostatectomy.

MATERIALS AND METHODS

Matched pairs analysis was performed comparing the 3 age cohorts 46 to 55, 56 to 65 and older than 65 years to a cohort of 435 patients who were 45 years or younger based on propensity scores calculated with all known preoperative variables. Postoperative clinical and pathological characteristics were compared among the 4 matched age cohorts. A Cox hazards model was used to compare time to prostate specific antigen recurrence across the different age cohorts and the actuarial risk of recurrence was calculated using Kaplan-Meier and log rank survivor analyses.

RESULTS

Younger patients showed lower grade disease (p <0.001), and lower rates of positive surgical margin rates (p = 0.035) and extraprostatic extension (p <0.001) but they did not have higher rates of lymph node involvement (p = 0.85) or seminal vesicle invasion (p = 0.56). Kaplan-Meier analysis showed no significant differences in biochemical recurrence across the age cohorts (log rank 0.38). On multivariate analysis prostatectomy Gleason score, pathological stage, positive surgical margins (each p <0.001) and preoperative prostate specific antigen (p = 0.04) were independently predictive of biochemical recurrence.

CONCLUSIONS

We report that increased age is not associated with worse biochemical outcomes following radical prostatectomy and it should not be considered an independent prognosticator for disease recurrence. Rather, age is a surrogate for known predictors of biochemical recurrence following surgery.

Brachytherapy in men aged <= 54 years with clinically localized prostate cancer

OBJECTIVE

To report the biochemical progression-free survival (BPFS) in hormone-naive men aged < or = 54 years who underwent brachytherapy with or without supplemental external beam radiation therapy (EBRT), as despite favourable biochemical control rates with brachytherapy, there remains a reluctance to recommend non-extirpative approaches for young men with clinically localized prostate cancer.

PATIENTS AND METHODS

From April 1995 to October 2002, 108 hormone-naive patients aged < or = 54 years (median 52 years, range 45-54) had permanent interstitial brachytherapy for clinical stage T1c-T2c NXM0 (2002 American Joint Committee on Cancer staging) prostate cancer. No patient had a seminal vesicle biopsy or pathological lymph node staging. The mean (sd, median) follow-up was 5.3 (1.8, 4.8) years. BPFS was defined by a prostate-specific antigen (PSA) level of < or = 0.40 ng/mL after the nadir. Risk groups were assigned using the Memorial Sloan-Kettering Cancer Center criteria. Several clinical, treatment and dosimetric variables were evaluated for their effect on BPFS.

RESULTS

For the entire group, the actuarial 8-year BPFS was 96%; for low- (57 men), intermediate- (47) and high- (four) risk patients, the BPFS rates were 96%, 100% and three of four, respectively. For biochemically disease-free patients, the median PSA level after treatment was 0.05 ng/mL. In a multivariate analysis, only pretreatment PSA level predicted biochemical control, while dosimetry variables after treatment were almost statistically significant.

CONCLUSIONS

Hormone-naive patients aged < or = 54 years have a high probability of a good 8-year BPFS after permanent interstitial brachytherapy with or without supplemental EBRT.

Does age matter in the selection of treatment for men with early-stage prostate cancer?

BACKGROUND

The specific aim of the current study was to compare freedom from biochemical failure, distant metastases-free survival, and overall survival in men age < or = 55 years, men ages 60 to 69 years, and men age > or = 70 years presenting with localized prostate cancer.

METHODS

A matched pair analysis compared patients age < or = 55 years (Group 1) who were treated with 3-dimension conformal radiation without androgen deprivation to men age > or = 60 years and < 70 years (Group 2), and men age > or = 70 years (Group 3) who were treated at the Fox Chase Cancer Center between November 1989 and October 2001. The groups were matched for disease stage (T1/T2b vs. T2C/T3), Gleason grade (2-6 vs. 7-10), radiation dose (< 70 Gray [Gy] vs. > or = 70-76 Gy vs. > or = 76 Gy), and pretreatment prostate-specific antigen (PSA) level. Estimates of outcome were accomplished using Kaplan-Meier methodology and compared by age group using the log-rank test.

RESULTS

Eighty-four men were identified according to the selection criteria. No statistically significant difference was found in the 5-year overall survival rates for Group 1, Group 2, and Group 3 (94%, 95%, and 87%, respectively) or the 5-year rate of freedom from biochemical failure in Group 1, Group 2, and Group 3 (82%, 76%, and 70%, respectively), or freedom from distant metastases (96%, 97%, and 98%, respectively).

CONCLUSIONS

Men age < or = 55 years who present with localized prostate cancer do not appear to have a worse prognosis. External beam radiation therapy appears to be a viable treatment alternative and should be offered to men age < or = 55 years who present with organ-confined prostate cancer.

The curative role of radiotherapy in adenocarcinoma of the prostate in patients under 55 years of age: a rare cancer network retrospective study

To determine whether radiation therapy could be an acceptable alternative to surgery in young patients with adenocarcinoma of the prostate, we analysed the outcome of 39 patients aged under 55 with organ confined tumours who received external radiation therapy in a curative intent. Our results suggest that similar local control in younger and older patients can be expected from either external beam radiotherapy or radical prostatectomy.

Influence of patient age on biochemical freedom from disease in patients undergoing conformal proton radiotherapy of organ-confined prostate cancer

OBJECTIVES

To examine a large, single-institution series of patients to test the perception among clinicians that radiotherapy is preferred for "older" patients and surgery should be indicated for "younger" men. Both radiotherapy and surgery are used to control prostate cancer, and both yield similar results in terms of long-term biochemical disease-free (bNED) survival.

METHODS

The bNED survival results from more than 1000 patients treated solely with conformal radiotherapy were analyzed to determine whether a difference in outcome supervened for patients younger than 60 years of age versus older patients.

RESULTS

No statistically significant difference in bNED survival was found, in terms of patient age. Statistically significant predictors of outcome included pretreatment prostate-specific antigen level, clinical stage at diagnosis, and Gleason score.

CONCLUSIONS

Patient age younger than 60 years versus older than 60 years at treatment did not influence bNED survival significantly. Patient age at treatment should not be used in and of itself to recommend one type of treatment over another.

Prostate dosimetry in an anthropomorphic phantom

Four field prostate treatments are a standard treatment procedure in radiotherapy. Dose in the prostate and rectum region were calculated for 6MV and 18MV photon beams on an anthropomorphic phantom with a collapsed cone convolution method using a 3-D planning system. Validation has been performed with radiographic film and thermoluminescent dosimeters. Results have shown that the pinnacle planning system has accurately modelled doses delivered to a heterogeneous phantom with calculations and measurements agreeing within +/-3% over most areas. When treating clinically, considerations such as the volume of bowel gas should be taken into account when planning. A sample of patient CT scans showed that in the absence of a heterogeneity correction, the error in estimated dose through the rectum could be as high as 8% in the presence of large volumes of rectal gas. Considerations, such as whether the patient undergoes another CT scan, the bowel gas volume ignored or assigned a specific density needs to be taken into account and brought to the attention of the radiation oncologists for accurate treatment.

Permanent interstitial brachytherapy in younger patients with clinically organ-confined prostate cancer

OBJECTIVES

To evaluate biochemical progression-free survival in hormone-naive men 62 years of age or younger with clinically organ-confined prostate cancer who underwent brachytherapy with or without supplemental external beam radiotherapy.

METHODS

From April 1995 through December 2000, 119 hormone-naive patients 62 years of age or younger underwent permanent interstitial brachytherapy for clinical T1b-T2cNxM0 (2002 American Joint Committee on Cancer) prostate cancer. No patient underwent seminal vesicle biopsy or pathologic lymph node staging. The median follow-up was 5.4 years. Biochemical progression-free survival was defined by either a prostate-specific antigen (PSA) level of 0.4 ng/mL or less after a nadir or by the American Society for Therapeutic Radiology and Oncology consensus definition. No patient was lost to follow-up. The clinical, treatment, and dosimetric parameters evaluated for biochemical progression-free survival included age, clinical T stage, Gleason score, pretreatment PSA level, risk group, percentage of positive biopsies, isotope, supplemental external beam radiotherapy, prostate volume, brachytherapy planning volume, percentage of the target volume receiving 100%, 150%, and 200% of the prescribed dose, minimal percentage of the prescribed dose covering 90% of the target volume, and tobacco status.

RESULTS

For the entire group, the actuarial 7-year biochemical progression-free survival rate was 96.1% and 98.3% for a PSA cutpoint of 0.4 ng/mL or less and for the American Society for Therapeutic Radiology and Oncology consensus definition, respectively. Using a PSA biochemical control definition of 0.4 ng/mL or less, 93.1%, 100%, and 95.2% of the low-risk, intermediate-risk, and high-risk hormone-naive patients were free of biochemical progression. The median post-treatment PSA level for the biochemically disease-free group was less than 0.1 ng/mL. In multivariate analysis, only the pretreatment PSA level predicted the biochemical outcome.

CONCLUSIONS

Hormone-naive patients 62 years of age or younger have a high probability of 7-year biochemical progression-free survival after permanent interstitial brachytherapy with or without supplemental external beam radiotherapy.

Comparison ofin vitroandin vivo / ratios for prostate cancer

Parallel in vitro and in vivo studies provide insight into the relationship between clinical response and intrinsic cellular radiosensitivity and may aid in the development of predictive assays. Compilations of radiosensitivity parameters from in vitro experiments can also be used to examine the potential effectiveness of alternative or new treatment plan designs until enough clinical data become available to directly estimate the requisite radiosensitivity parameters. In this work, survival data for six prostate cancer cell lines (ten datasets total) have been extracted from the literature and re-analysed using the linear-quadratic (LQ) survival model. The paired bootstrap technique for regression is used to compute 95% confidence intervals for the estimated radiosensitivity parameters. LQ radiosensitivity parameters derived from the in vitro data are then compared to radiosensitivity parameters derived from clinical data for prostate cancer. Estimates of alpha range from 0.09 to 0.35 Gy(-1) (all cell lines), and the alpha/beta ratio ranges from 1.09 to 6.29 Gy (all cell lines). Point estimates of the repair half-time (PPC-1, TSU-Pr1, PC-3 and DU-145 cell lines) range from 5.7 to 8.9 h (95% confidence interval from 0.26 h to 10.7 h). Differences in the radiosensitivity parameters determined from the data reported by different laboratories are as large as or larger than the differences in radiosensitivity parameters observed among the various prostate cell lines. The reported studies demonstrate that even seemingly small corrections for dose rate effects, such as those expected in high dose rate (HDR) experiments, can sometimes have a significant impact on estimates of alpha and alpha/beta. By neglecting dose rate effects in the analysis of HDR experiments, estimates of the alpha/beta, ratio may be too high by factors as large as 1.3 to 6.2. The half-time for repair derived from the in vitro experiments appears significantly larger (slower repair rate) than estimates derived from the clinical data. However, the prostate radiosensitivity parameters alpha and alpha/beta may be approximately the same in vitro and in vivo. Most of the in vitro data are consistent with an alpha/beta ratio for prostate cancer less than 3 or 4 Gy.

Do younger men have better biochemical outcomes after radical prostatectomy?

OBJECTIVES

To examine the relationship between age and biochemical failure after radical prostatectomy (RP), controlling for the year of surgery. Prior studies have suggested that younger men have lower prostate-specific antigen recurrence rates after RP, although none of the prior studies had controlled for the year of surgery.

METHODS

We examined the data from 1753 men treated with RP between 1988 and 2002 at five equal access medical centers. We compared age, as a categorical variable according to decade of life (50 years old or younger, 51 to 60, 61 to 70, and older than 70 years), with the clinical and pathologic variables at RP, as well as the time to biochemical recurrence, using a multivariate Cox proportional hazards model.

RESULTS

Age was significantly related to the year of surgery, with the more recently treated patients being younger than less recently treated patients (P <0.001). After controlling for the year of surgery, the younger men had smaller prostates, fewer high-grade tumors on biopsy, and less lymph node metastasis, but a greater percentage of cores with cancer. On multivariate analysis, men 50 years old or younger had significantly lower recurrence rates than did the older men. Moreover, men older than 70 years had significantly greater prostate-specific antigen failure rates than men aged 51 to 70 years or men aged 50 years or younger.

CONCLUSIONS

The average age of men undergoing RP has decreased with time. Independent of this, young men have more favorable outcomes after RP than older men. Continued screening to detect prostate cancer among younger men when it is most curable appears warranted.

External beam radiotherapy in elderly patients with clinically localized prostate adenocarcinoma: age is not a problem

The files of 183 elderly patients aged >70 years, with localized prostate cancer (T1-3, N0-X, M0), treated with radical external radiation therapy (ERT) from January 1992 to December 2001 at the Radiotherapy Department of the Istituto Nazionale Tumori of Milan, were reviewed. Median age was 75 years. ERT represented the sole treatment for 73 patients (39.9%); in 110 cases (60.1%) hormonal therapy (HT) was associated with neoadjuvant intent. Five-year overall, disease-specific and biochemical NED (bNED) survival rates were 90.2, 93.7 and 63.2%, respectively. A subset of 23 patients aged 80 years and over were analyzed and compared to 160 men aged 70-79 years. Acute toxicity and late complications were analyzed in the two groups of patients according to the RTOG scoring system. Only 10 patients (5.4%) showed grades 2-3 (G2-3) late sequelae. The results obtained in this single-institute series highlight the pivotal role of ERT in the management of clinically localized prostate cancer in the elderly.

Long-term durability of PSA failure-free survival after radiotherapy for localized prostate cancer

PURPOSE

To determine the durability of prostate-specific antigen (PSA) progression-free survival beyond 5 years in patients biochemically free of relapse 5 years after external beam radiotherapy (EBRT).

METHODS AND MATERIALS

This study identified 328 men treated with EBRT to the prostate who were biochemically (American Society for Therapeutic Radiology and Oncology definition) disease free 5 years after treatment. The median follow-up was 7.4 years. The patients were divided into four groups according to their PSA values 5 years after treatment: PSA <or=0.5, 0.5 to <or=1.0, 1.0 to <or=2.0, and 2.0-4.0 ng/mL. PSA progression-free rates were calculated in each subgroup at 10 years after treatment. Yearly hazard rates of biochemical progression were also calculated for the 5-10 years after treatment.

RESULTS

The PSA progression-free survival rate was 87%, 79%, and 67%, respectively, 8, 10, and 13 years after treatment in patients biochemically free of disease 5 years after treatment. The progression-free rates at 10 years after treatment according to the PSA level at 5 years was 92% for PSA <or=0.5 ng/mL; 71% for PSA 0.5 to <or=1.0 ng/mL; 78% for PSA 1.0 to <or=2.0 ng/mL; and 56% for PSA 2.0 to <or=4.0. The lower the PSA level at 5 years, the more durable the probability of maintained biochemical disease-free survival (p <0.0001). The yearly hazard rates of biochemical progression ranged from 3.1% to 6.6% in the 5-10 years after RT.

CONCLUSION

When PSA levels remain low (<2 ng/mL) 5 years after EBRT, the great majority of patients will be biochemically disease free at 10 years. The hazard rates of biochemical progression in the 6-10 years after treatment are low and are comparable to those published for prostatectomy series.

Five-year biochemical outcome after prostate brachytherapy for hormone-naive men < or = 62 years of age

PURPOSE

To evaluate 5-year biochemical disease-free outcome for hormone naïve men 62 years of age or less who underwent transperineal ultrasound-guided permanent prostate brachytherapy.

METHODS AND MATERIALS

76 patients underwent transperineal ultrasound guided prostate brachytherapy using either (103)Pd or (125)I for clinical T1b--T2b NxM0 (1997 AJCC) adenocarcinoma of the prostate gland from April 1995 to October 1999. No patient was lost to follow-up, and no patient underwent pathologic lymph-node staging. 47 patients were implanted with either (103)Pd or (125)I monotherapy, and 29 patients received moderate-dose external-beam radiation therapy followed by a prostate brachytherapy boost. No patient received hormonal manipulation. The median patient age was 58 years (range, 48--62 years). The median follow-up was 37 months (range, 14--70 months). Follow-up was calculated from the day of implantation. Biochemical disease-free survival was defined by the American Society of Therapeutic Radiation and Oncology (ASTRO) consensus definition.

RESULTS

The actuarial 5-year biochemical disease-free survival rate was 98.7%. For patients with low-, intermediate-, and high-risk disease, 97.7%, 100%, and 100%, respectively, were free of biochemical failure. The median posttreatment prostate-specific antigen (PSA) for the entire group was 0.2 ng/mL. When stratified by risk group, the median posttreatment PSA was 0.2, 0.15, and 0.1 for patients with low-, intermediate-, and high-risk disease, respectively.

CONCLUSION

With a median follow-up of 37 months, hormone naïve patients < or = 62 years of age have a high probability of 5-year biochemical disease-free survival following permanent prostate brachytherapy with an apparent plateau on the PSA curve.

The durability of external beam radiation therapy for prostate cancer: can it be identified?

PURPOSE

We establish criteria to identify a durable response to external beam radiation therapy by calculation of biochemical progression-free probability for patients who attained and maintained defined nadir prostate specific antigen (PSA) levels more than 5 years after treatment.

MATERIALS AND METHODS

A total of 460 patients were treated with external beam radiation monotherapy from 1976 to 1995. Patients with PSA less than 0.5 (group 1) or 0.5 to 1.0 (group 2) ng./ml. more than 5 years after treatment were identified. Treatment failure was defined as 3 consecutive increases in PSA after nadir. Progression-free probability after 60 months was calculated for each group. A comparison was also made to patients achieving the same nadir levels anytime after treatment.

RESULTS

Failure occurred at 133 months in 1 of 26 group 1 patients (4%) and at a median of 76 months in 5 of 26 group 2 patients (19%). At 10 years progression-free probability was 91% for group 1 compared to 72% for group 2 (p = 0.0575). These same nadir levels anytime after treatment were associated with higher failure rates of 55% for group 1 and 72% for group 2.

CONCLUSIONS

If a PSA nadir of less than 0.5 ng./ml. was maintained 5 years after therapy, subsequent failure was rare. Although statistical significance was not reached (p = 0.0575), a higher failure rate was noted if the nadir PSA was 0.5 to 1.0 ng./ml. at 5 years. Thus, patients with PSA 0.5 to 1.0 ng./ml. require careful continued surveillance. Nadir levels less than 1.0 ng./ml. anytime before 5 years were associated with a substantial risk of subsequent progression.

Update on the treatment of prostate cancer with external beam irradiation

BACKGROUND

We review the recent changes in the radiotherapeutic management of clinically localized prostate cancer, including the implementation of three-dimensional (3-D) conformal radiation therapy (3DCRT), biochemical disease-free survival (bNED control) using conventional and 3DCRT techniques, and the morbidity of these treatment strategies.

METHODS

The components of 3DCRT are discussed, including patient immobilization, 3-D treatment planning, multileaf collimation, and electronic portal imaging. bNED control rates from institutions using conventional and 3DCRT techniques are compared. The gastrointestinal (GI) and genitourinary (GU) morbidity from prospective trials using conventional doses of radiation are compared to data from 3DCRT series. bNED control rates stratified by pretreatment prostate-specific antigen (PSA) are compared between surgical and radiation series.

RESULTS

bNED control rates (3-5 years) for patients treated with conventional and 3DCRT techniques ranged from 44-70% and 30-72% with pretreatment PSA levels 4-10 and 10-20, respectively. Although direct comparisons are difficult between treatment modalities, no difference in bNED control stratified by pretreatment PSA was observed between surgical and radiation patients.

CONCLUSIONS

Patients with clinically localized prostate cancer treated with 3DCRT demonstrate durable bNED control at 5 years. Conformal radiation techniques, multileaf collimation, electronic portal imaging, and patient immobilization have reduced acute and chronic GI and GU morbidity while allowing safe dose escalation in an effort to further improve local control and overall survival.

Age-related prostate cancer metastases

OBJECTIVES

Metastatic prostate cancer results in significant patient morbidity, health care expenditure, and ultimately in mortality. We sought to identify patient and treatment factors predictive of distant metastases in patients completing external beam radiotherapy.

METHODS

Five hundred sixty-seven patients completing external beam radiotherapy at Fox Chase Cancer Center, Philadelphia, Pennsylvania between March 1987 and November 1994 for Stage T1 to T3 tumors were analyzed. Distant metastases were detected by radionuclide bone scans. Estimates of rates for distant metastases as a first failure were conducted using cumulative incidence methods and predictors of failure were analyzed univariately and multivariately.

RESULTS

The median follow-up was 46 months. On univariate analysis, the following were statistically significant predictors of distant metastases at 5 years: patient age greater than 65 years, pretreatment prostate-specific antigen (PSA) level, advanced stage, lower radiation dose, and Gleason score 7 to 10. Multivariate testing confirmed that age greater than 65 years, high pretreatment PSA level, lower radiation dose, and advanced stage were significant independent predictors of distant metastases.

CONCLUSIONS

Men over the age of 65 years are more likely to experience distant failure than are younger men. The discovery of age-related differences in patterns of failure has significant therapeutic implications with regard to patient selection, trial design, and adjuvant therapy recommendations. Furthermore, age-related differences in failure may influence comparison of outcome data for radiotherapy series, which tend to have older patients, to surgical reports that usually include significantly younger men.

[Indications and results of exclusive radiotherapy in early prostatic adenocarcinoma]

Prostate adenocarcinoma incidence are rising rapidly, especially in early stages. Even if some of these carcinomas may be latent or slow growing either spontaneously or under hormonal therapy, most patients 75 years old or less presenting a localized tumor, T1b-c, T2, T3, N0, M0, whatever the grading, will require treatment with curative intent: radical prostatectomy, external beam radiation therapy (ERT) and/or brachytherapy. After ERT limited to the prostate or including seminal vesicles and/or pelvic lymph nodes, the overall survival and the survival without clinical evolution at 5, 10 and 15 years are good. However survival rates without biochemical evolution are about 30% lower and 70% or less at 5 years for the more favorable group (T < or = T2a and Gleason < 7 and PSA < 10 ng/mL). Brachytherapy alone yields good results for the same favorable group. In the unfavorable group (T > or = 2c and Gleason > or = 7 and PSA > or = 20 ng/mL), adjuvant hormonal therapy improves survival. Conformal radiation therapy allows an increase in dose to the tumor by about 15% without increasing complications. It can increase the biological remission rate in the intermediate group (T < or = 2a or Gleason > or = 7 or PSA > or = 20 ng/mL).

Health-related quality of life in Australian men remaining disease-free after radical prostatectomy

OBJECTIVE

To determine the health-related quality of life (HRQOL) of Australian men after radical prostatectomy.

DESIGN

Cross-sectional study.

SETTING

Private and public practices of three urologists in south-east Queensland, July 1989 to June 1995.

PARTICIPANTS

140 men with no evidence of disease recurrence 1 to 6 years after radical prostatectomy.

MAIN OUTCOME MEASURES

Voiding and erectile potency and HRQOL. Recall of preoperative status and status at survey were established by an independently administered multi-item questionnaire.

RESULTS

112 men (80%) completed the study questionnaire. Difficulty with bladder control before the operation was reported by 25 (22%; 95% confidence interval [CI], 15%-31.2%), and the incontinence rate after treatment was 22/112 (20%; 95% CI, 12.7%-28.2%). Men with incontinence after operation were more likely to recall preoperative urinary symptoms. Eighty-four (75%) men were happy or coping with their sexual function after radical prostatectomy despite an erectile potency rate of only 12% (95% CI, 7%-20%). Twenty-eight (25%) had tried penile injections and three have had penile prostheses since their operation. Impotence was reported more frequently (40%) as the treatment-related problem most affecting life, followed by "concern about cancer" (12%) and incontinence (8%). Impotence was also the most common cause given for diminished HRQOL.

CONCLUSIONS

Loss of sexual function after radical prostatectomy is more commonly perceived as a major problem and is more likely than urinary incontinence to adversely affect HRQOL. Loss of sexual function and its effect on HRQOL needs to be given greater emphasis in counselling before radical prostatectomy.

Is there an increased risk of second primaries following prostate irradiation?

PURPOSE

To assess the risk of developing a second primary cancer following prostate irradiation compared to the underlying risk in patients with prostate cancer.

METHODS AND MATERIALS

The baseline rate of secondary cancers following prostate cancer was obtained from a study of 18,135 patients from the Connecticut Tumor Registry, of whom only 12.5% received radiotherapy. These patients, with a mean age of 72 and a mean follow-up of 3.9 years, were compared to a cohort of 543 patients (median age 70) with similar follow-up (median 3.9 years), all of whom were treated with definitive radiotherapy at Fox Chase Cancer Center. The possible association between various covariates (age, dose, palpation stage, field size, Gleason score, pretreatment PSA) and the development of a secondary cancer was assessed.

RESULTS

1,053 of 18,135 patients (5.8%) in the Connecticut Tumor Registry developed a second primary cancer compared with 31 of 543 (5.7%) patients treated with prostate radiation (p = 0.99). Although this risk increases gradually over time, it is not significantly different, at any time period, between the two groups of patients. Of the 31 secondary primaries in the irradiated group, 82% had a history of tobacco and/or alcohol use. Only melanomas were significantly increased compared to the expected rate in an age-matched population (p < 0.001). Five of the 31 secondary cancers occurred within the radiation field (four bladder, one colon), four within 3 years and only one occurred 9 years after radiotherapy. No association was found between age (<70 vs. > or =70 and as a continuous variable), dose (<74 vs. > or =74 Gy), palpation stage (<T2C vs. > or =T2C), field size (prostate vs. pelvic), radiation technique (conventional vs. conformal), Gleason score (2-6 vs. 7-10), or pretreatment PSA (<15 vs. > or =15 and as a continuous variable) and the risk of developing a second primary. Although a lower radiation dose (as a continuous variable) correlated with an increased risk of developing a secondary cancer (p = 0.04), this phenomenon is likely due to differences in follow-up time.

CONCLUSION

Up to at least 10 years, there is no increased risk of developing a second primary cancer following prostate irradiation compared to the baseline rate from prostate cancer itself. This risk is not higher in younger patients with localized disease (<T2C), who often must choose between surgery and radiation. The vast majority of secondary cancers occurred outside of the radiation field (84%) and/or within 3 years of radiotherapy (97%), suggesting they were not caused by radiation. Most of these patients had lifestyles with predisposing risk factors. Patients with prostate cancer manifested a significantly increased risk of developing melanomas, suggesting that they may benefit from patient education and skin screening examinations.

Radiotherapy options for localized prostate cancer based upon pretreatment serum prostate-specific antigen levels and biochemical control: a comprehensive review of the literature

PURPOSE

To review all the available radiotherapy (RT) literature on localized prostate cancer treatment where serum prostate-specific antigen (PSA) levels were used to both stratify patients and evaluate outcome and determine if any conclusions can be reached regarding an optimal radiotherapeutic management for this disease.

METHODS AND MATERIALS

A MEDLINE search was conducted to obtain all articles in English on prostate cancer treatment employing RT from 1986-1997. Studies were considered eligible for review only if they met all the following criteria: 1) pretreatment PSA values were recorded and grouped for subsequent evaluation, 2) posttreatment PSA values were continuously monitored, 3) definitions of biochemical control were stated, and 4) the median follow-up was given.

RESULTS

Of the 246 articles identified, only 20 met the inclusion criteria; 4 using conformal external beam RT, 8 using conventional external beam RT, and 8 using interstitial brachytherapy (4 using a permanent implant alone, 3 combining external beam RT with a permanent implant, and 1 combining a conformal temporary interstitial implant boost with external beam RT). No studies using neutrons (with or without external beam RT) or androgen deprivation (combined with external beam RT) were identified where patients were stratified by pretreatment PSA levels. Results for all therapies were extremely variable with the 3-5-year rates of biochemical control for patients with pretreatment PSA levels < or = 4 ng/ml ranging from 48 to 100%, for PSA levels >4 and < or = 10 ng/ml ranging from 44 to 90%, for PSA levels >10 and < or = 20 ng/ml ranging from 27 to 89%, and for PSA levels >20 ranging from 14 to 89%. The median Gleason score, T-stage, definition of biochemical control, and follow-up were substantially different from series to series. No RT option consistently produced superior results.

CONCLUSIONS

When data are reviewed from studies using serum PSA levels to stratify patients and to evaluate treatment outcome, no consistently superior RT technique was identified. These data suggest that standard definitions of disease stage (combining clinical, pathologic, and biochemical criteria) and a common definition of biochemical cure (as developed by the American Society for Therapeutic Radiology and Oncology Consensus Panel) need to be adopted to evaluate treatment efficacy and advise patients on the most appropriate radiotherapeutic option for their disease.

Sensitivity of human prostatic carcinoma cell lines to low dose rate radiation exposure

PURPOSE

Low dose rate radioemitters, such as 125I, 103Pd, and 89Sr, have been used both for local and systemic treatment of prostate cancer. Most normal cells exposed to ionizing radiation characteristically activate cell cycle checkpoints, resulting in cell cycle arrest at the G1/S and G2/M transition points. Cancer cells are typically quite sensitive to radiation killing late in the G2 phase of the replicative cell cycle. Furthermore, most cancer cells accumulating at the G2/M transition point as a result of low dose rate radiation exposure appear to become sensitive to further low dose rate irradiation. For this reason, protracted exposure of cancer cells to low dose rate radiation has been proposed to result in increased cancer cell killing as compared with brief exposures of cancer cells to high dose rate radiation. Since many human prostatic carcinomas contain somatic genome alterations targeting genes which affect the cell cycle and radiation-associated cell cycle checkpoints, we evaluated the effects of low dose rate radiation exposure on the cell cycle and on clonogenic survival for various human prostatic carcinoma cell lines.

MATERIALS AND METHODS

Human prostatic carcinoma cells from the LNCaP, DU 145, PC-3, PPC-1, and TSU-Pr1 cell lines were exposed to low dose rate (0.25 Gy/hour) or high dose rate (60 Gy/hour) radiation in vitro and then assessed for radiation cytotoxicity by clonogenic survival assay. Cell cycle perturbations following protracted exposure to low dose rate radiation were evaluated using flow cytometry.

RESULTS

For LNCaP cells, low dose rate radiation exposure resulted in an accumulation of cells at both the G1/S and the G2/M cell cycle transition points. For DU 145, PC-3, PPC-1, and TSU-Pr1 cells, treatment with low dose rate radiation triggered G2/M cell cycle arrest, but not G1/S arrest. Unexpectedly, the cell cycle redistribution pattern phenotypes observed, G1/S and G2/M cell cycle arrest versus G2/M arrest alone, appeared to have little effect on low dose rate radiation survival. Furthermore, while PC-3, PPC-1, and TSU-Pr1 cells exhibited increased cytotoxic sensitivity to low dose rate versus fractionated high dose rate radiation treatment, DU 145 and LNCaP cells did not.

CONCLUSIONS

Radiation-associated pertubations in replicative cell cycle progression were not dominant determinants of low dose rate radiation killing efficacy in human prostate cancer cell lines in vitro.

Conformal external beam treatment of prostate cancer

OBJECTIVES

This study reports the 5-year outcomes of treatment for patients with prostate cancer treated largely with conformal three-dimensional radiation therapy.

METHODS

Results are presented for 456 consecutive patients treated prior to December 31, 1993 whose pretreatment prostate-specific antigen (PSA) levels are known. Biochemical failure was defined as two consecutive rises in the PSA that equals or exceeds 1.5 ng/mL. Kaplan-Meier product limit methods, the log-rank test, and Cox regression models were used in evaluating the data. No patient was lost to follow-up.

RESULTS

The 5-year biochemically free of failure (bNED) rate for all patients was 61% and 57% at 7 years. In the group with pretreatment PSA less than 10 ng/mL, the 5-year bNED rate for patients with localized disease (T1,2AB disease, Gleason sum of 6 or less) was 85% and for those with locally advanced disease (T2C,3), 70%. In the group with pretreatment PSA of 10 to 19.9 ng/mL, the 5-year bNED rate for patients with localized disease was 66% and for those with locally advanced disease, 44%. In the group with pretreatment PSA of 20 ng/mL or above, the patients with localized or locally advanced disease had 5-year bNED rates of 31% and 21%, respectively.

CONCLUSIONS

The results of largely conformal three-dimensional external beam treatment of localized prostate cancer produced 5-year bNED results that are comparable to recent reports of nerve-sparing prostatectomy. Preliminary 7-year bNED results in all patients and in patients with localized tumors indicated a modest decrease in the cancer-free rate from that observed at 5 years, suggesting the results are durable.