Christopher A Warlick

Johns Hopkins University, Baltimore, Maryland, United States

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Publications (11)40.12 Total impact

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    ABSTRACT: The natural history of prostate cancer is remarkably heterogeneous and, at this time, not completely understood. The widespread adoption and application of prostate-specific antigen (PSA) screening has led to a dramatic shift toward the diagnosis of low-volume, nonpalpable, early-stage tumors. Autopsy and early observational studies have shown that approximately 1 in 3 men aged >50 years has histologic evidence of prostate cancer, with a significant portion of tumors being small and possibly clinically insignificant. Utilizing the power of improved contemporary risk stratification schema to better identify patients with a low risk of cancer progression, several centers are gaining considerable experience with active surveillance and delayed, selective, and curative therapy. A literature review was performed to evaluate the rationale behind active surveillance for prostate cancer and to describe the early experiences from surveillance protocols. It appears that a limited number of men on active surveillance have required treatment, with the majority of such men having good outcomes after delayed selective intervention for progressive disease. The best candidates for active surveillance are being defined, as are predictors of active treatment. The psychosocial ramifications of surveillance for prostate cancer can be profound and future needs and unmet goals will be discussed.
    Full-text · Article · Apr 2008 · Cancer
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    ABSTRACT: We updated our experience with a strategy of expectant treatment for men with stage T1c prostate cancer and evaluated predictors of disease intervention. A total of 407 men with a median age of 65.7 years (range 45.8 to 81.5) with stage T1c (99.8%) or T2a (0.2%) prostate cancer suspected of harboring small volume prostate cancer based on needle biopsy findings and prostate specific antigen density have been followed in a prospective, longitudinal surveillance program with a median followup of 2.8 years (range 0.4 to 12.5). A recommendation for treatment was made if disease progression was suggested by unfavorable followup needle biopsy findings (Gleason pattern 4 or 5, greater than 2 biopsy cores with cancer or greater than 50% involvement of any core with cancer). Cox proportional hazards regression was used to evaluate the affect of multiple covariates on the outcome of curative intervention. Of 407 men 239 (59%) men remained on active surveillance at a median followup of 3.4 years (range 0.43 to 12.5), 103 (25%) underwent curative intervention at a median of 2.2 years after diagnosis (range 0.96 to 7.39) and 65 (16%) were either lost to followup (12), withdrew from the program (45), or died of causes other than prostate cancer (8). Older age at diagnosis (p = 0.011) and an earlier date of diagnosis (p = 0.001) were significantly associated with curative intervention. Recognizing that over treatment of prostate cancer is prevalent, especially among elderly patients, a program of careful selection and monitoring of older men who are likely to harbor small volume, low grade disease may be a rational alternative to the active treatment of all.
    Preview · Article · Jan 2008 · The Journal of urology
  • Jared Berkowitz · Christopher Warlick · Amanda North · John P Gearhart
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    ABSTRACT: The authors report a rare variant of the exstrophy-epispadias complex in which the patient has two bladders and complete duplication of müllerian structures. We also discuss the treatment of the patient's orthopedic and genitourinary conditions. The patient's prognosis is excellent, and she is expected to be fully continent, able to void spontaneously, and conceive children.
    No preview · Article · Nov 2007 · Urology
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    ABSTRACT: Initial publications on postchemotherapy laparoscopic retroperitoneal lymph node dissection (LRPLND) have described significant intraoperative and postoperative morbidities. This report reviewed the complication rate with additional experience. A retrospective review of the medical records of 16 consecutive patients who underwent postchemotherapy LRPLND by a single surgeon from September 1996 to September 2005 was performed. The evaluation included tumor type, clinical stage, pathologic stage, and intraoperative and postoperative complications. Postchemotherapy LRPLND was successfully performed in 14 (87.5%) of 16 patients. Seven patients (43.8%) developed complications and 2 (12.5%) required open conversion. The most complications occurred during the postoperative period and were classified as minor. Of the total patient population, 25% had minor postoperative complications. The median hospital stay was 2 days. No patient who underwent the procedure died. All intraoperative complications were vascular injuries and occurred during the first half of the series (1996 to 2000). In the second half of the series (2000 to 2005), no complications during the operative period and no vascular or major complications occurred. No retroperitoneal recurrence was noted during a mean follow-up of 32.7 months (range 5 to 108). One patient developed distant recurrence and underwent successful salvage chemotherapy. Postchemotherapy LRPLND remains a challenging, but feasible, operation. With greater experience, the incidence of complications and morbidity can be reduced.
    No preview · Article · Mar 2007 · Urology
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    ABSTRACT: Evacuation of clot from the bladder by irrigation can be difficult when significant clot burden or organized clot exists. We describe a novel technique for the evacuation of clot from the bladder using irrigation containing hydrogen peroxide that facilitated clot removal.
    No preview · Article · Jan 2007 · Urology
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    ABSTRACT: Using various nonphysiological tissue injury/repair models numerous studies have demonstrated the capacity of bone marrow derived cells to contribute to the repopulation of epithelial tissues following damage. To investigate whether this phenomenon might also occur during periods of physiological tissue degeneration/regeneration we compared the ability of bone marrow derived cells to rejuvenate the prostate gland in mice that were castrated and then later treated with dihydrotestosterone vs mice with prostate epithelium that had been damaged by lytic virus infection. Using allogenic bone marrow grafts from female donor transgenic mice expressing green fluorescent protein transplanted into lethally irradiated males we were able to assess the contributions of bone marrow derived cells to recovery of the prostatic epithelium in 2 distinct systems, including 1) surgical castration followed 1 week later by dihydrotestosterone replacement and 2) intraprostatic viral injection. Eight to 10-week-old male C57/Bl6 mice were distributed among bone marrow donor-->recipient/prostate injury groups, including 5 with C57/Bl6-->C57/Bl6/no injury, 3 with green fluorescent protein-->C57/Bl6/no injury, 3 with green fluorescent protein-->C57/Bl6/vehicle injection, 4 with green fluorescent protein-->C57/Bl6/virus injection and 3 each with green fluorescent protein-->C57/Bl6/castration without and with dihydrotestosterone, respectively. Prostate tissues were harvested 3 weeks after dihydrotestosterone replacement or 14 days following intraprostatic viral injection. Prostate tissue immunofluorescence was performed with antibodies against the epithelial marker cytokeratin 5/8, the hematopoietic marker CD45 and green fluorescent protein. Mice that sustained prostate injury from vaccinia virus infection with concomitant severe inflammation and glandular disruption showed evidence of bone marrow derived cell reconstitution of prostate epithelium, that is approximately 4% of all green fluorescent protein positive cells in the epithelial compartment 14 days after injury expressed cytokeratin 5/8, similar to the proportion of green fluorescent protein positive cells in the prostate that no longer expressed the hematopoietic marker CD45. When prostatic degeneration/regeneration was triggered by androgen deprivation and reintroduction, no green fluorescent protein positive prostate epithelial cells were detected. These findings are consistent with a requirement for inflammation associated architectural destruction for the bone marrow derived cell contribution to the regeneration of prostate epithelium.
    No preview · Article · Sep 2006 · The Journal of Urology
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    ABSTRACT: Percutaneous renal tumor cryoablation is being evaluated as a treatment option for small renal tumors. However, when tumors are located centrally, involvement of the collecting system by the radiographic iceball can occur. We reviewed our series of computed tomography (CT)-guided percutaneous renal tumor cryoablation to identify those cases in which there appeared to be involvement of the collecting system by the radiographic iceball and to determine any clinical sequelae of such involvement. Retrospective review of the medical records identified 6 patients who had undergone CT-guided percutaneous renal tumor cryoablation with evidence of collecting system involvement. Measurements of the tumor size, size of the radiographic iceball, and the size of the immediate postprocedure "cryozone" (region of apparent treatment on contrast-enhanced CT) were obtained from the preprocedure, intraprocedure, and immediate postprocedure CT scans. Follow-up imaging was obtained beginning at 3 to 6 months. Six patients were identified who met the inclusion criteria and had at least 3 months of documented follow-up. Despite the apparent involvement of the collecting system during the cryoablation procedure, no patient developed clinical signs or symptoms or radiographic evidence of a urine leak or fistula formation. Furthermore, no evidence of ureteral narrowing or stricture formation has been found to date, with a mean follow-up of 167.7 days (range 90 to 288). We observed no clinically appreciable urine leaks despite what appeared to be obvious involvement of the collecting system by the radiographic iceball. However, care should be exercised to avoid this insult when possible until additional research has confirmed its safety.
    No preview · Article · Jun 2006 · Urology
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    ABSTRACT: For prostate cancer patients with small, lower-grade tumors, expectant management with delayed surgical intervention (active surveillance) is a rarely used therapeutic option because the opportunity for cure may be lost. We compared outcomes of 38 patients with small, lower-grade prostate cancer in an expectant management program who underwent delayed surgical intervention at a median of 26.5 months (95% confidence interval [CI] = 17 to 32 months; range = 12.0-73.0 months) after diagnosis with 150 similar patients who underwent immediate surgical intervention at a median of 3.0 months (95% CI = 2 to 4 months; range = 1.0-9.0 months) after diagnosis. Noncurable cancer was defined as adverse pathology associated with a less than 75% chance of remaining disease-free for 10 years after surgery. Noncurable cancer was diagnosed in nine (23%) of the 38 patients in the delayed intervention cohort and in 24 (16%) of the 150 men in the immediate intervention group. After adjusting for age and prostate-specific antigen (PSA) density (i.e., PSA value divided by prostate volume) in a Mantel-Haenszel analysis, the risks of noncurable cancer associated with delayed and immediate intervention did not differ statistically significantly (relative risk = 1.08, 95% CI = 0.55 to 2.12; P = .819, two-sided Cochran-Mantel-Haenszel statistic). Age, PSA, and PSA density were all statistically significantly associated with the risk of noncurable cancer (P = .030, .013, and .008, respectively; two-sided chi-square test). Thus, delayed prostate cancer surgery for patients with small, lower-grade prostate cancers does not appear to compromise curability.
    Full-text · Article · Apr 2006 · Journal of the National Cancer Institute
  • Source
    Warlick C · Trock BJ · Landis P

    Full-text · Article · Jan 2006
  • Christopher A Warlick · Ranjiv Mathews · Arlene C Gerson

    No preview · Article · Jan 2006 · Urology
  • Christopher A Warlick · Mohamad E Allaf · H Ballentine Carter
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    ABSTRACT: Expectant treatment with curative intent for treatment of low-risk prostate cancer faces 3 challenges in the PSA era: (1) appropriate patient selection, (2) adequate surveillance strategies, and (3) identification of triggers for definitive intervention when cure is still possible. Men 65 years or older with T1c disease, prostate-specific antigen density <0.15 ng/ml/cm3, and favorable biopsy characteristics per the Epstein criteria currently appear to be the safest candidates for expectant treatment. Changes in biopsy characteristics are the most objective trigger for definitive therapy currently in use. Outcomes data are still required to determine the safety of expectant treatment for localized disease.
    No preview · Article · Jan 2006 · Urologic Oncology

Publication Stats

701 Citations
40.12 Total Impact Points


  • 2008
    • Johns Hopkins University
      Baltimore, Maryland, United States
  • 2006-2008
    • Johns Hopkins Medicine
      • Department of Urology
      Baltimore, Maryland, United States
    • AMD
      Sunnyvale, California, United States