"Check out this article below about cryotherapy of the prostate. Our Miami urologist, Dr. Amery Wirtshafter contributed many patients to this valuable study evaluating the use of cryoablation for high grade prostate cancer."
Primary cryoablation for Gleason 8, 9, or 10 localized prostate cancer:Biochemical and local control outcomes from the Cryo OnLine database registry J. Stephen Jones and John C.
Rewcastle1 Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, OH, USA 1Department of Radiology,
University of Calgary, Calgary, AB, Canada For correspondence: Dr. J. Stephen Jones, Glickman Urological Institute,
Cleveland Clinic Foundation, A-100, 9500 Euclid Ave., Cleveland, OH 44195, USA. E-mail: [email protected] This is an
open-access article distributed under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Other
Sections? Abstract INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION REFERENCESAbstract Introduction
and Objective: The increased use of cryoablation as an initial treatment for localized high-grade prostate cancer
has been due to many factors including reports that cell kill from exposure to cryogenic temperatures is independent
of cellular dedifferentiation and Gleason score. The objective of this study is to report the outcomes of primary
cryoablation when used to treat Gleason 8, 9, or 10 localized prostate cancer at a large number of centers.
Materials and Methods: Data from 1608 patients who underwent primary cryoablation at 27 centers were collected using
the Cryo OnLine Database (COLD) registry. This analysis considers only the 77 patients who had a Gleason score of at
least 8 and a minimum of 24 months of follow-up. Biochemical failure was defined according to both the original
ASTRO definition (three rises) and the 2006 updated ASTRO (Phoenix) definition of nadir + 2. Biopsy was performed at
the physician's discretion, but most commonly if a patient had a rising or suspicious prostate specific antigen
(PSA). Results: The average age at treatment was 69.6 ± 8.2 years. Pretreatment PSA was 16.2 ± 17.9
ng/ml and the average Gleason was 8.5 ± 0.6. Patients were followed for 39.0 ± 18.8 months (range:
24-120 months) and 5-year follow-up was available for 12 patients. Eight-seven percent of the patients achieved a
PSA nadir < 0.4 ng/ml. Five-year actuarial biochemical survivals was 64.4 ± 6.0% and 44.6 ± 8.0%
for the ASTRO and Phoenix definitions, respectively. A total of 47 underwent posttreatment biopsy. Of these, 12
showed evidence of disease resulting in a positive biopsy rate for those who underwent biopsy of 25.5%. This yields
a positive biopsy rate of the entire population of 15.6% (12/77). Conclusions: Cryoablation, as a primary treatment
for high-grade Gleason prostate cancer practiced over a wide spectrum of users provides definable biochemical and
local control for a hard to manage patient population with aggressive disease. Keywords: Cryotherapy, prostate
cancer, minimally invasive Other Sections? Abstract INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION
REFERENCESINTRODUCTION Despite the well-recognized stage migration that has led to an improvement in prostate cancer
outcomes since the era of prostate specific antigen (PSA)-based prostate cancer screening began, patients with
high-grade prostate cancer remain at significant risk of morbidity and mortality.[1] Patients with Gleason score
>8 cancer are often treated with radical prostatectomy or radiotherapy combined with adjuvant androgen blockade.
Some patients have confounding factors limiting their ability to undergo surgery, including age, anesthetic risks,
or simply refusal of surgical intervention. External beam radiotherapy in combination with 6-24 months'
hormonal ablation offers a nonsurgical alternative, and brachytherapy or the combination of external beam
radiotherapy with brachytherapy is used for some high-risk patients as well. These options carry substantial risk of
complications, including erectile dysfunction, incontinence, or damage to the surrounding structures that continue
to limit their acceptance for some patients. Moreover, the efficacy of any modality decreases in patients with
high-grade disease.[1]Cryosurgical ablation has been used in many centers as a minimally invasive alternative to
surgery and radiation that has the potential to eradicate prostate cancer irrespective of tumor grade. Unlike
radiotherapy, cryoablation appears to reproducibly kill all cells frozen to lethal temperatures.[2] This has led to
the suggestion that it may be preferentially useful for patients with high-grade disease.[3]This study reports a
relatively large group of patients diagnosed with Gleason 8, 9, or 10 prostate cancer who underwent cryoablation as
their primary therapy. Patient data were collected with the Cryo OnLine Database (COLD) registry. Other Sections?
Abstract INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION REFERENCESMATERIALS AND METHODS The COLD
registry is a secure web-based registry consisting of case report forms designed to collect relevant pre- and
post-treatment information for patients undergoing prostate cryoablation. A central institutional review board's
approval covers the collection and analysis of deidentified data, additional IRB approval for individual centers has
been obtained when required by institutional policy. Investigators who have entered data into the COLD registry are
listed in the acknowledgments.Only patients with Gleason score 8 or greater having minimum 24 months follow-up were
included in this analysis. Patients undergoing cryotherapy following failure of prior definitive radiotherapy or
brachytherapy, and those that had undergone focal, nerve sparing, or nerve warming treatment were excluded. A total
of 77 patients from 27 centers were identified meeting the criteria.Biochemical failure was defined according to
both the original ASTRO definition of three consecutive rises following nadir (referred to as ?ASTRO?), and the
second ASTRO definition of nadir + 2 (referred to as the ?Phoenix? definition). Biopsy was performed at the
physician's discretion, but most commonly if a patient had a rising or suspicious PSA.Kaplan-Meier analysis was
used to generate curves showing the probability biochemical failure as a function of time. Statistical analysis was
performed with a commercially available statistical software package (MedCalc, Mariakerke, Belgium). Other Sections?
Abstract INTRODUCTION MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION REFERENCESRESULTS Data were collected from
27 investigators. The average age of the 77 patients who met the inclusions criteria was 69.6 ± 8.2 years.
Pretreatment PSA was 16.2 ± 17.9 ng/ml and the average Gleason was 8.5 ± 0.6. Patients were followed
for 39.0 ± 18.8 months (range: 24-120 months) and 12 patients had a follow-up of at least 60 months.
Posttreatment, 87% of the patients achieved a PSA nadir < 0.4 ng/ml. The 5-year actuarial biochemical survivals
are 64.4 ± 6.0% and 44.6 ± 8.0% for the ASTRO and Phoenix definitions, respectively [Figure 1]. After
treatment, 47 underwent biopsy. Of these, 12 showed evidence of disease. The positive biopsy rate, for those who
underwent posttreatment biopsy was 25.5% and the rate for the entire population was 15.6% (12/77). No fistulas were
identified in any of the patients. Figure 1 Kaplan-Meier curve of the cumulative biochemical disease free survival
probability using (a) the ASTRO definition and (b) the Phoenix definition Other Sections? Abstract INTRODUCTION
MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSION REFERENCESDISCUSSION The COLD registry project is designed to
address the relative paucity of published data regarding cryotherapy for prostate cancer. It is notable, however,
that opinions regarding the quality and quantity of data published on radical prostatectomy, external beam
radiation, and active surveillance are perhaps overstated. For example, the Kaplan-Meier 5-year biochemical disease
free survival data for high-risk prostate cancer managed with external beam radiotherapy as shown in Campbell's
Urology textbook is based upon a surprisingly low six patients with at least 60 months follow-up. Similarly, the
present series reports only 12 patients with results at 5 years. We believe that both datasets are inadequate to
make solid declarations of long-term efficacy. That being said, the authors do feel it is important to realize that
the data supporting any form of treatment for the high-risk patient is lacking[1] and that the concept that
radiation therapy is clearly established as a more efficacious treatment for high-risk disease must be
scrutinized.Emerging technologies are often reserved in initial series to low-risk patients in whom failure to
control disease carries less risk of metastasis and death. For example, most initial brachytherapy series are
heavily weighted toward patients with low-risk disease.[4] Moreover, even recent radical prostatectomy and radiation
series include more low risk than high-risk patients, but this is at least partially due to high-risk disease being
less common in screened populations.[5,6] In contrast, early pioneers of cryotherapy advocated the position that if
lethal cold temperatures are achieved, uniform necrosis results and cell death occurs irrespective of cellular
differentiation or Gleason score.[2] In addition, publications suggesting its potential to treat locally advanced
disease has led to the concept of freezing beyond the prostatic capsule to eliminate extraprostatic disease that
would have resulted in a positive surgical margin had radical prostatectomy been performed.[7] As a result,
cryoablation is often utilized for the treatment of high-risk localized prostate cancer. Several publications of
intermediate-term results have suggested that the efficacy of the procedure appears to be equivalent to radiation
and surgery for low-risk prostate cancer and potentially more efficacious for moderate- and high-risk prostate
cancer.[8?11] A summary of the efficacies reported in the four publications reporting 5 year outcomes exclusively
for primary cryoablation is presented in Table 1. Table 1 Biochemical disease free survival at 5 years following
cryoablation: Reports in the literature As of yet there is no universally agreed upon definition of biochemical
failure following cryotherapy, but it should be noted that consensus definitions also remain relatively elusive
following radiation or surgery. Radical prostatectomy completely removes the prostate and should theoretically yield
an undetectable PSA. However, some residual PSA remains detectable in many patients due to a small number of
remaining benign glands. The American Urological Association (AUA) Guidelines Panel recommended in 2007 that the
definition of biochemical success does not require an undetectable PSA, and that failure should be a PSA > 0.2
ng/ml confirmed by a second PSA reading > 0.2.[12] Further, the AUA panel found 166 different published
definitions of biochemical failure, including 99 for patients undergoing radiation failure. In 1998 the first ASTRO
definition of three consecutive rises, backdated to the midpoint of the first rise, was agreed upon by a consensus
panel and became standard practice. It is the ASTRO definition that has been used most commonly following
cryoablation. This is based on the similarity of cryoablation and radiation therapy in that both modalities result
in some residual prostatic tissue and low but measurable PSA levels in most patients. The second ASTRO definition,
dubbed the ?Phoenix? definition, remains somewhat controversial in the eyes of many urologists. Although it was
specified that it was not intended for use with patients undergoing cryotherapy, we have included our results using
this as an additional definition solely for comparative purposes.[13]Early cryotherapy experience made it clear that
specific thresholds may be meaningless due to PSA production by residual tissue surrounding the urethra or in a
benign median lobe, and the fact that a PSA of 0.4 is expected when 1 g of prostate tissue has been preserved in men
free of prostate cancer.[14] It is intended that the data set collected with the COLD registry will be used to
create a scientifically based definition of biochemical failure that is specific to primary prostate cancer
cryoablation as these data accumulate and mature.The use of negative biopsies as a surrogate for disease control is
also controversial. Regardless of the intervention, sampling error underestimates disease when using biopsy as a
surrogate. This is especially likely when small volume disease is present, as evidenced by the 61% of men known to
have prostate cancer that have a negative repeat sextant biopsy when evaluated on an active surveillance
protocol.[15] Seventeen percent of patients with known prostate cancer on an active surveillance protocol have a
negative biopsy even when saturation biopsy is performed.[16] Some authors suggest that histological evidence of
malignancy identified on biopsy should not be regarded as cancer in some postradiation settings.[17] In contrast,
following cryoablation, histological results tend to fall into one of three definitive categories: fibrous tissue
(scar) indicating tumor eradication, benign prostate tissue, or prostate cancer.[18] When cryotherapy was first
investigated most patients underwent posttreatment biopsy to confirm local control. However, due to high-negative
biopsy rates (82-98%)[8,9] most practitioners now utilize biopsy only to investigate suspicious PSA values or
patterns.[19] It is not possible to know what the positive biopsy rate would be for those not determined to warrant
biopsy by the treating physicians, but previous series have suggested that the likelihood of residual disease is low
as demonstrated in the table.The primary limitation of this series is the retrospective nature of a registry. There
is the potential that patients with unfavorable features are not voluntarily reported to the registry, or that
unfavorable outcomes are inaccurately reported. Our experience in dealing directly with the physician members and
with internal audit is that we have found no evidence that there is any case selection, and to our knowledge all
cases of the enrolling physicians are included. In addition, a wide variety of surgical techniques is possible with
the large number of institutions participating. However, a primary goal of the COLD registry is to determine
outcomes in ?the real world? without the inherent reporting bias of single surgeon series. These data suggest that
bDFS and complication rates are consistent with earlier single-center reports. CONCLUSION The biochemical and local
control of cryoablation for high Gleason score prostate cancer appear to be consistent both with early reports of
cryoablation and with large series reporting experience with radiation and surgery. Improving data available on all
treatment modalities for localized prostate cancer is mandatory for patients to make an informed decision on
therapy. Acknowledgments This analysis is based on data entered into the COLD registry. The contributing
investigators include: AN Avallone, Grand Rapids, MI; DK Bahn, Ventura, CA; BT Brown, Daytona Beach, FL; A Cantwell,
Daytona Beach, FL; DO Chinn, Arcadia, CA; M Chinn, Arcadia, CA; R Chopra, Port Orange, FL; FC Derrick, Charleston,
SC; M Dineen, Daytona Beach, FL; HB Epstein, St. Augustine, FL; J Foley, Easton, MD; RW Given, Norfolk, VA; M
Grable, Orange City, FL; RF Graves, Scottsbluff, NE; JM Greenberg, Tucson, AZ; R Kahnoski, Grand Rapids, MI; AE
Katz, New York, NY; DL Laub, Santa Barbara, CA; MA Melser, Port Charlotte, FL; M Merrell, Daytona Beach, FL; KR
Orton, Tucson, AZ; TH Patterson, Galesburg, IL; R Regan, Daytona Beach, FL; GS Rosenberg, Hackensack, NJ; SM
Scionti, Hilton Head Island, SC; J Wescott, Daytona Beach, FL; AR Wirtshafter, Miami Beach, FL. Footnotes Source of
Support: The COLD registry is supported through an educational grant from Endocare, Inc. Conflict of Interest: None
declared. Other Sections:
Abstract
INTRODUCTION
MATERIALS AND METHODS
RESULTS
DISCUSSION
CONCLUSION
REFERENCES
