Riccardo Valdagni

Active Surveillance for Low-Risk Prostate Cancer Worldwide: The PRIAS Study

BACKGROUND Overdiagnosis and subsequent overtreatment are important side effects of screening for, and early detection of, prostate cancer (PCa). Active surveillance (AS) is of growing interest as an alternative to radical treatment of low-risk PCa. OBJECTIVE To update our experience in the largest worldwide prospective AS cohort. DESIGN, SETTING, AND PARTICIPANTS Eligible patients had clinical stage T1/T2 PCa, prostate-specific antigen (PSA) ≤ 10 ng/ml, PSA density <0.2 ng/ml per milliliter, one or two positive biopsy cores, and Gleason score ≤ 6. PSA was measured every 3-6 mo, and volume-based repeat biopsies were scheduled after 1, 4, and 7 yr. Reclassification was defined as more than two positive cores or Gleason >6 at repeat biopsy. Recommendation for treatment was triggered in case of PSA doubling time <3 yr or reclassification. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Multivariate regression analysis was used to evaluate predictors for reclassification at repeat biopsy. Active therapy-free survival (ATFS) was assessed with a Kaplan-Meier analysis, and Cox regression was used to evaluate the association of clinical characteristics with active therapy over time. RESULTS AND LIMITATIONS In total, 2494 patients were included and followed for a median of 1.6 yr. One or more repeat biopsies were performed in 1480 men, of whom 415 men (28%) showed reclassification. Compliance with the first repeat biopsy was estimated to be 81%. During follow-up, 527 patients (21.1%) underwent active therapy. ATFS at 2 yr was 77.3%. The strongest predictors for reclassification and switching to deferred treatment were the number of positive cores (two cores compared with one core) and PSA density. The disease-specific survival rate was 100%. Follow-up was too short to draw definitive conclusions about the safety of AS. CONCLUSIONS Our short-term data support AS as a feasible strategy to reduce overtreatment. Clinical characteristics and PSA kinetics during follow-up can be used for risk stratification. Strict monitoring is even more essential in men with high-risk features to enable timely recognition of potentially aggressive disease and offer curative intervention. Limitations of using surrogate end points and markers in AS should be recognized. TRIAL REGISTRATION The current program is registered at the Dutch Trial Register with ID NTR1718 (http://www.trialregister.nl/trialreg/admin/rctview.asp?TC=1718).

miR-205 Exerts Tumor-Suppressive Functions in Human Prostate through Down-regulation of Protein Kinase Cε

Limited information is available concerning the expression and role of microRNAs in prostate cancer. In this study, we investigated the involvement of miR-205 in prostate carcinogenesis. Significantly lower miR-205 expression levels were found in cancer than in normal prostate cell lines as well as in tumor compared with matched normal prostate tissues, with a particularly pronounced reduction in carcinomas from patients with local-regionally disseminated disease. Restoring the expression of miR-205 in prostate cancer cells resulted in cell rearrangements consistent with a mesenchymal-to-epithelial transition, such as up-regulation of E-cadherin and reduction of cell locomotion and invasion, and in the down-regulation of several oncogenes known to be involved in disease progression (i.e., interleukin 6, caveolin-1, EZH2). Our evidence suggests that these events are driven by the concurrent repression of specific predicted miR-205 targets, namely N-chimaerin, ErbB3, E2F1, E2F5, ZEB2, and protein kinase Cepsilon. Strikingly, the latter seemed to play a direct role in regulating epithelial-to-mesenchymal transition. In fact, its down-regulation led to a cell phenotype largely reminiscent of that of cells ectopically expressing miR-205. Overall, we showed for the first time that miR-205 exerts a tumor-suppressive effect in human prostate by counteracting epithelial-to-mesenchymal transition and reducing cell migration/invasion, at least in part through the down-regulation of protein kinase Cepsilon.

Dose–volume effects for normal tissues in external radiotherapy: Pelvis

A great deal of quantitative information regarding the dose-volume relationships of pelvic organs at risk has been collected and analysed over the last 10 years. The need to improve our knowledge in the modelling of late and acute toxicity has become increasingly important, due to the rapidly increasing use of inverse-planned intensity-modulated radiotherapy (IMRT) and the consequent need of a quantitative assessment of dose-volume or biological-based cost functions. This comprehensive review concerns most organs at risk involved in planning optimisation for prostate and other types of pelvic cancer. The rectum is the most investigated organ: the largest studies on dose-volume modelling of rectal toxicity show quite consistent results, suggesting that sufficiently reliable dose-volume/EUD-based constraints can be safely applied in most clinical situations. Quantitative data on bladder, bowel, sexual organs and pelvic bone marrow are more lacking but are rapidly emerging; however, for these organs, further investigation on large groups of patients is necessary.

Rectal dose–volume constraints in high-dose radiotherapy of localized prostate cancer

PURPOSE To investigate the relationship between rectal bleeding and dosimetric-clinical parameters in patients receiving three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer. METHODS In a retrospective national study (AIROPROS01-01, AIRO: Associazione Italiana Radioterapia Oncologica), planning/clinical data for 245 consecutive patients with stage T1-4N0-x prostate carcinoma who underwent 3D-CRT to 70-78 Gy (ICRU point) were pooled from four Italian institutions. The correlation between late rectal bleeding and rectal dose-volume data (the percentage of rectum receiving more than 50, 55, 60, 65, 70, and 75 Gy [V(50-70)]) and other dosimetric and clinical parameters were investigated in univariate (log-rank) and multivariate (Cox regression model) analyses. Median follow-up was 2 years. RESULTS Twenty-three patients were scored as late bleeders according to a modified RTOG definition (Grade 2: 16; Grade 3: 7); the actuarial 2-year rate was 9.2%. Excepting V75, all median and third quartile V(50-70) values were found to be significantly correlated with late bleeding at univariate analysis. The smallest p value was seen for V(50) below/above the third quartile value (66%). The V70 (cut-off value: 30%) was found to be also predictive for late bleeding. In the high-dose subgroup (74-78 Gy), Grade 3 bleeding was highly correlated with this constraint. The predictive value of both V(50) and V(70) was confirmed by multivariate analyses. CONCLUSIONS The present article provides evidence for correlation between rectal DVH parameters and late rectal bleeding in patients treated with curative intent with 3D-CRT. To keep the rate of moderate/severe rectal bleeding below 5-10%, it seems advisable to limit V(50) to 60-65%, V(60) to 45-50%, and V70 to 25-30%.

Short-term outcomes of the prospective multicentre ‘Prostate Cancer Research International: Active Surveillance’ study

Study Type – Therapy (prospective cohort)
Level of Evidence 2b

Radical radiation alone versus radical radiation plus microwave hyperthermia for N3 (TNM-UICC) neck nodes: a prospective randomized clinical trial☆

Between September 1985 and December 1986, 44 N3 (TNM-UICC) metastatic squamous cell cervical lymph-nodes were randomized to receive conventionally fractionated radical irradiation (RT) to a total dose of 64-70 Gy, or conventionally fractionated radical irradiation plus twice a week local microwave hyperthermia (Ht). The two major end points of this study were (a) local control rates evaluated at 3 months after the end of combined therapy and (b) incidence of acute local toxicity. Thirty-six nodes (82%) were evaluable as of December 1986, at which time there was a premature closure of this study due to ethical reasons. An interim analysis had revealed a statistically significant difference in complete response rates in favor of the combined arm (p = 0.0152). The complete response rates were 82.3% (14/17) for the combined treatment arm versus 36.8% (7/19) for the control irradiation arm, leading to an iso-dose thermal enhancement ratio (TER) value of 2.23. Both arms are comparable in average total RT dose delivered (RT: 67.05 Gy; RT + Ht: 67.85 Gy) and in average maximum node diameter (RT arm: 4.81 cm; RT + Ht: 4.88 cm). Acute local toxicities were similar in irradiated and heated plus irradiated neck regions; only one skin burn was observed. As possible treatment related death, one patient in the RT + Ht arm died 2 months after completion of therapy with a carotid rupture associated with extensive tumor necrosis. These results confirm previous non-randomized reports suggesting that hyperthermia in combination with full dose conventionally fractionated irradiation significantly enhances the chance of early local control of fixed N3 neck nodes without exhibiting an increase of acute local toxicity.

miR-21: an oncomir on strike in prostate cancer.

BackgroundAberrant expression of microRNAs, small non-coding RNA molecules that post-transcriptionally repress gene expression, seems to be causatively linked to the pathogenesis of cancer. In this context, miR-21 was found to be overexpressed in different human cancers (e.g. glioblastoma, breast cancer). In addition, it is thought to be endowed with oncogenic properties due to its ability to negatively modulate the expression of tumor-suppressor genes (e.g. PTEN) and to cause the reversion of malignant phenotype when knocked- down in several tumor models. On the basis of these findings, miR-21 has been proposed as a widely exploitable cancer-related target. However, scanty information is available concerning the relevance of miR-21 for prostate cancer. In the present study, we investigated the role of miR-21 and its potential as a therapeutic target in two prostate cancer cell lines, characterized by different miR-21 expression levels and PTEN gene status.ResultsWe provide evidence that miR-21 knockdown in prostate cancer cells is not sufficient per se i) to affect the proliferative and invasive potential or the chemo- and radiosensitivity profiles or ii) to modulate the expression of the tumor-suppressors PTEN and Pdcd4, which in other tumor types were found to be regulated by miR-21. We also show that miR-21 is not differently expressed in carcinomas and matched normal tissues obtained from 36 untreated prostate cancer patients subjected to radical prostatectomy.ConclusionsOverall, our data suggest that miR-21 is not a central player in the onset of prostate cancer and that its single hitting is not a valuable therapeutic strategy in the disease. This supports the notion that the oncogenic properties of miR-21 could be cell and tissue dependent and that the potential role of a given miRNA as a therapeutic target should be contextualized with respect to the disease.

Important prognostic factors influencing outcome of combined radiation and hyperthermia

Clinical experience with combined local-regional hyperthermia and radiation therapy has been rapidly accumulating over the past few decades. Its superior efficacy to the use of radiation alone has been demonstrated in several retrospective and prospective reports in the literature. It is evident now that there are several important factors that will influence the final outcome of the treated patients. The parameters that will be discussed in this paper include: I. Pretreatments factors: 1. tumor dimension 2. tumor histology 3. tumor site. II. Treatment factors: 1. radiation therapy dose 2. hyperthermia parameters: (a) thermal variables (b) number of heat treatments (c) sequence of hyperthermia and radiation treatments (d) hyperthermic device. Finally, evaluation of response and complications will also be discussed. The importance of abiding by an accepted reporting system will be emphasized, and clarification of times at which response assessments were made will also be discussed. With the availability of longer term follow-up, use of an actuarial method of reporting becomes more important. The future of hyperthermia and radiation remains very promising but a lot of questions still need to be answered by well-conducted and reported clinical trials.

Radical Prostatectomy for Low-Risk Prostate Cancer Following Initial Active Surveillance: Results From a Prospective Observational Study

BACKGROUND Little is known about the outcome of radical prostatectomy (RP) in men initially followed on active surveillance (AS) for low-risk prostate cancer (PCa). OBJECTIVE Evaluate pathology findings after RP in our prospective AS cohort. DESIGN, SETTING, AND PARTICIPANTS All men participated in the Prostate Cancer Research International: Active Surveillance (PRIAS) study. Eligible men were initially diagnosed with low-risk PCa (clinical stage ≤ T2, prostate-specific antigen [PSA] ≤ 10 ng/ml, PSA density <0.2 ng/ml per ml, one or two positive biopsy cores, and Gleason score ≤ 6) and underwent RP between December 2006 and July 2011. The study protocol recommends RP in case of risk reclassification on repeat biopsy (Gleason score >6 and/or more than two positive cores) or a PSA doubling time ≤ 3 yr. MEASUREMENTS Descriptive statistics were used to report on pathology findings for staging and grading. RESULTS AND LIMITATIONS Pathology results were available in 167 out of 189 RP cases (88.4%). Median time to RP was 1.3 yr (range: 1.1-1.9). Protocol-based recommendations led to deferred RP in 143 men (75.7%); 24 men (12.7%) switched because of anxiety, and 22 (11.6%) had other reasons. Pathology results showed 134 (80.8%) organ-confined cases and 32 (19.2%) cases with extracapsular extension. Gleason scores ≤ 6, 3+4, 4+3, and 8 were found in 79 (47.3%), 64 (38.3%), 21 (12.6%), and 3 (1.8%) cases, respectively. Unfavourable RP results (pT3-4 and/or Gleason score ≥ 4+3) were found in 49 patients (29%), of whom 33 (67%) had a biopsy-related reason for deferred RP. CONCLUSIONS RP results in men initially followed on AS show organ-confined disease and favourable Gleason grading in a majority of cases. Most men in our cohort had a protocol-based reason to switch to deferred RP. A main focus for AS protocols should be to improve the selection of patients at the time of inclusion to minimise reclassification of risk and preserve the chance for curative treatment, if indicated.

A Decade of Active Surveillance in the PRIAS Study: An Update and Evaluation of the Criteria Used to Recommend a Switch to Active Treatment

BACKGROUND The Prostate Cancer Research International Active Surveillance (PRIAS) study was initiated a decade ago to study the most optimal selection and follow-up of men on active surveillance (AS). OBJECTIVE We report on 10 yr of follow-up of men on AS in the PRIAS study and evaluate if criteria used to recommend a switch to active treatment truly predict unfavorable outcome on subsequent radical prostatectomy (RP). DESIGN, SETTING, AND PARTICIPANTS Men with low-risk prostate cancer were included and followed prospectively on AS. Follow-up consisted of regular prostate-specific antigen (PSA) tests, digital rectal examinations, and biopsies. Men with Gleason >3+3, more than two positive biopsy cores, or stage higher than cT2 were advised to switch to active treatment (until 2014, a PSA doubling time [PSA DT] of 0-3 yr was also used). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Reclassification rates, treatment after discontinuation, and outcome on RP after discontinuing AS were reported. Regression analysis on the outcome of RP was used to evaluate the predictive value of criteria currently used to recommend a switch to active treatment. Kaplan-Meier and competing risk analysis were used to report discontinuation rates over time and long-term oncologic end points. RESULTS AND LIMITATIONS A total of 5302 men were included in PRIAS across 18 countries. Reclassification rates remained stable on all subsequent biopsies, with 22-33% of men having either Gleason >3+3 or more than two positive cores on any repeat biopsy. At 5 and 10 yr of follow-up, 52% and 73% of men, respectively, had discontinued AS, most of them because of protocol-based reclassification. A third of men undergoing subsequent RP had favorable pathologic tumor features (Gleason 3+3 and pT2). Of the criteria used to recommend a switch to active treatment, more than two positive cores and a PSA DT of 0-3 yr were not predictive of unfavorable pathologic outcome on RP. CONCLUSIONS A substantial group of men discontinued AS without subsequent unfavorable tumor features on RP; therefore, we propose Gleason upgrading and cT3 as the only indicators for an immediate switch to active treatment. Surrogate indicators (eg, more than two positive cores and a fast-rising PSA) should not trigger immediate active treatment but rather further investigation to confirm the suspicion of higher risk disease. PATIENT SUMMARY We confirmed the safety of active surveillance as a treatment option for men with low-risk prostate cancer; however, some changes could be made to the follow-up protocol to safely increase the number of men who remain on active surveillance.