On-target activity of neoadjuvant cixutumumab and combined androgen deprivation therapy for high-risk prostate cancer: A phase II trial

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Background: IMC-A12 (cixutumumab) is a fully human monoclonal antibody which targets the insulin-like growth factor receptor 1. Preclinical data suggests that the combination of androgen deprivation and IMC-A12 is much more effective than either treatment alone. This clinical trial tests the effectiveness of the combined treatment in a neoadjuvant fashion before radical prostatectomy. We have assayed serum samples from the first 18 patients to identify signs of on-target activity in this setting.

Methods: Eligible men with high risk localized prostate cancer are defined by one of the following: Gleason score ≥ 8, PSA ≥ 20, Clinical Stage T2c-T3, or a risk for relapse exceeding 50% as defined by the Kattan nomogram. Men are treated for 3 months with goserelin, bicalutamide, and biweekly IMC-A12 infusions (10 mg/kg). The primary objective of the trial is to determine the rate of pathological complete response with an accrual goal of 28 men. Using samples from the first 18 patients on study, serum protein markers were assayed by ELISA and serum PSA and glucose levels were determined by clinical laboratory analysis.

Results: Significant increases in c-peptide (1.7-fold, p<0.01), IGF-I (4.1-fold, p<0.01), IGF-II (1.32-fold, p<0.001), IGFBP-3 (1.9-fold, p<0.01), growth hormone (8-fold, p<0.01) were noted after initiation of ADT+IMC-A12, compared to pre-treatment levels. Non-significant increases of insulin (1.9-fold), IGFBP-1 (2-fold), and glucose (1.24-fold) levels were seen. Stratification of patients by nadir PSA levels correlated with residual tumor volume, likelihood of positive surgical margins and likelihood of lymph node metastases. Interestingly, patients with lower nadir PSA levels had smaller increases in c-peptide (50%, p<0.01), insulin (66%, p<0.02) and blood sugar (21%, P<0.01) compared to the patients with higher nadir PSA levels.

Conclusions: Combined with ADT in the neoadjuvant setting, IMC-A12 effectively targets the IGF-1R axis in prostate cancer patients. Metabolic differences between patients may alter the efficacy of IMC-A12 in this setting.

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Rate of delivery of hyperbaric oxygen treatments does not affect response in soft tissue radionecrosis

BACKGROUND

Soft tissue radiation necrosis (STRN) is effectively treated with hyperbaric oxygen (HBO,), believed to result from stimulation ofangiogenesis in radiation-injured tissue. Thirty to forty HBO2 treatments are usually recommended for STRN. For various reasons, different hyperbaric facilities offer these treatments once or twice daily and from 5-7 days weekly. It is not known whether the clinical response differs as a result of the rate of administration of HBO2 treatments.

METHODS

Details of hyperbaric treatment courses of patients treated for radiation enteritis/proctitis (n = 65) and cystitis (n = 94) at a single institution were reviewed. Outcomes were compared with the total number of HBO2 treatments administered and also rate of treatment administration.

RESULTS

Responses were similar for both forms of STRN whether the patient averaged fewer or greater than 5 treatments per week, or even < or = 3 versus > or = 7 treatments weekly. Outcome did differ, however, dependant on the total number of treatments administered. Response was better in patients receiving 30 or more total treatments, as compared with fewer.

CONCLUSIONS

Soft tissue radionecrosis of the gastrointestinal tract or bladder is (1) effectively treated with hyperbaric oxygen, (2) has a higher response rate if at least 30 treatments are administered, and (3) is equally responsive to rates of hyperbaric treatment ranging from 3 or fewer to 7 or more treatments per week.

Randomized trial of active cellular immunotherapy with sipuleucel-T in androgen dependent prostate cancer (ADPC)

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Background: Sipuleucel-T is an investigational, active cellular immunotherapy product for prostate cancer. To explore the potential benefit in ADPC, sipuleucel-T was studied in a randomized, double blind, multicenter, placebo controlled study, P-11. Methods: ADPC patients with a rise in serum prostate specific antigen (PSA) as the only sign of disease recurrence after prostatectomy were randomized (2:1) to sipuleucel-T or placebo, administered in weeks 0, 2, and 4, following 3-months of hormonal therapy. PSA kinetics were evaluated by time to biochemical failure (BF), defined as any PSA = 3 ng/mL (primary endpoint), as well as PSA doubling time (PSADT). Clinical endpoints included time to distant metastases (DF) and survival. The effect of a single booster infusion of sipuleucel-T on the immune system was also evaluated. Results: 176 patients were randomized (117 sipuleucel-T:59 placebo) and analyzed by intent to treat. Median time to BF was 18.0 months for sipuleucel-T and 15.4 months for placebo (hazard ratio (HR)=0.94 [95% confidence interval (CI): 0.64, 1.38]; p>0.05, log rank). The hazard ratio for BF was 0.80 in favor of sipuleucal-T ([95%CI: 0.53, 1.20], p>0.05) when the analysis was restricted to patients with a confirmed BF. An analysis of PSADT calculated from 90 days following randomization to BF or the initiation of systemic therapy demonstrated that patients randomized to sipuleucel-T had a 35% increase in PSADT (125 vs 91 days; p=0.046, F-test). PSADT calculated after testosterone recovery to baseline levels demonstrated a 48% increase in PSADT for the sipuleucel-T arm (155 vs 105 days; p=0.038). Only 16% of patients developed distant metastases. The hazard ratio for time to DF was 0.78 (95%CI: 0.34, 1.58, p>0.05, log rank). Patients are still being followed for DF and survival. The most common treatment-associated adverse events were chills, fatigue, headache, and pyrexia, which were primarily Grade 1–2. Conclusions: Time to BF was not different between the two study arms. The effect on PSADT, an important prognostic indicator in ADPC, may suggest the biologic activity of sipuleucel-T in this population. Additional follow-up for clinical endpoints of DF and survival is of interest.

No significant financial relationships to disclose.

Erectile function following unilateral cavernosal nerve graft

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Background: Over the past 20 years, radical prostatectomy has been a mainstay in the treatment of localized prostate cancer. With the adoption of nerve-sparing procedures, select patients may avoid the consequence of erectile dysfunction.Certain patients who are not candidates for nerve-sparing procedures may be eligible for nerve interposition grafts. While bilateral cavernosal nerve grafting after radical prostatectomy has shown efficacy, the effect of unilateral nerve grafting remains unclear. To further ascertain this outcome, we evaluated a large group of patients who underwent a unilateral cavernosal nerve replacement. Methods: Forty patients underwent unilateral nerve sparing surgery with concomitant contralateral cavernosal nerve replacement by a single surgeon from 2002 to 2006. Patient were selected based upon pre-op nomogram risk assessment, endorectal MRI evidence of extra capsular disease or intraop histology demonstrating margin positivity. Age, demographic data, Gleason score, clinical and pathologic stage and pre and post op IIEF data was collected and prospectively analyzed. An additional phone interview was conducted to assess outcomes and morbidity. Results: Full demographic and interview data was available for 28 of 40 patients (70%). Median follow-up was 19 months. The median age at RRP was 53 with a median pre-operative PSA of 6.5. Median pre- and post-op IIEF scores were 25 and 15 respectively. Median change in IIEF scores was 7.5. 22 of 28 patients (79%) men report being able to penetrate after surgery. 17 of those 22 (77%) continue to require PDE-5 inhibitors to facilitate penetration. 3 of the 6 patients (50%) who were unable to have intercourse following nerve replacement received adjuvant hormonal or radiation therapy. 27 patients (96%) reported numbness at the graft harvest site with three (10.7%) describing this as bothersome. One patient experienced a graft site infection and two of 28 (7.1%) patients reported pain at the harvest site. Conclusion: Unilateral sural nerve grafting is a feasible and well-tolerated approach for patients who must undergo wide resection of a neurovascular bundle. While men do show a sizable decrease in their IIEF score, 79% were able to achieve penetration following surgery. The majority of men require PDE-5 inhibitors to facilitate intercourse.

No significant financial relationships to disclose.

Adenocarcinoma of the testicular adnexa presenting with metastatic disease

Primary epididymal adenocarcinoma is a rare malignancy with fewer than 30 documented cases. We report a case of a 57-year-old patient with a paratesticular mass in the presence of retroperitoneal metastatic disease. Histology confirmed the presence of primary paratesticular adenocarcinoma. In this report we review the index case, the pertinent literature and discuss adjuvant therapy.

Comparison of complications after radical and partial nephrectomy: results from the National Veterans Administration Surgical Quality Improvement Program

OBJECTIVE

To determine whether radical nephrectomy causes less morbidity, less mortality and is associated with a shorter hospital stay than is partial nephrectomy.

PATIENTS AND METHODS

A total of 1885 nephrectomies (1373 radical and 512 partial) conducted between 1991 and 1998 in the Department of Veterans Affairs (VA) National Surgical Quality Improvement Program were evaluated. Using multivariate analyses, outcomes were risk-adjusted based on 45 preoperative variables to compare mortality and morbidity rates.

RESULTS

The unadjusted 30-day mortality was 2.0% for radical and 1.6% for partial nephrectomy (P = 0.58). Risk-adjusting the two groups did not result in a statistically significant difference in mortality. The 30-day overall morbidity rate was 15% for radical and 16.2% for partial nephrectomy (P = 0.52); risk-adjusted morbidity rates were not statistically different. There were no statistically significant differences in the rates of postoperative progressive renal failure, acute renal failure, urinary tract infection, prolonged ileus, transfusion requirement, deep wound infection, or extended length of stay.

CONCLUSIONS

Partial nephrectomy carried out in the VA program has low morbidity and mortality rates, comparable with the complication rates after radical nephrectomy.

Fournier's gangrene in a modern surgical setting: improved survival with aggressive management

OBJECTIVE

To examine the outcome of 23 consecutive patients with Fournier's gangrene.

PATIENTS AND METHODS

Patients' charts were reviewed retrospectively from all those treated for Fournier's gangrene between July 1994 and July 1997 at the UCLA affiliated hospitals.

RESULTS

Twenty-three patients were identified (mean age 51.7 years, range 13-71). The aetiologies included perirectal abscess (43%), urethral stricture (30%), scrotal abscess (21%) and unknown (4%). Predisposing factors included diabetes mellitus (43%), steroids or chemotherapy (21%), alcohol abuse (43%), malignancy (26%) and radiation therapy (9%). All 23 patients initially received wide debridement and placement of a percutaneous suprapubic tube. At the time of the first surgery, total scrotectomy was required in all, colostomy in 17% and penectomy in 4%. An additional 35% required eventual colostomy and an additional 9% required a penectomy. Patients underwent repeat debridement a mean of 2.5 times; the overall survival was 96%.

CONCLUSION

Survival can be improved in patients with Fournier's gangrene by combining aggressive surgical and medical management. The keys to successful outcome included a high index of suspicion, prompt fluid resuscitation, rapid initiation of broad-spectrum antibiotics, a multidisciplinary approach, early surgical intervention with radical debridement, haemodynamic support in an intensive care setting, and frequent repeat operative debridement.

Recognition of prostate-specific antigenic peptide determinants by human CD4 and CD8 T cells

It is now becoming accepted that one is not tolerant to all the determinants of self proteins: the T cell repertoire directed to some sequences in self proteins is intact and can be activated. When a self protein is exclusively expressed by tumour cells, the T cell repertoire directed to the particular self antigen can potentially be activated to attack the tumour: this would amount to induction of a beneficial autoimmune response. Prostate cancer offers a unique opportunity for activation of a tumour-specific immune response owing to the exclusive synthesis of prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSM) by prostatic tissue and prostate tumour cells. In this study we examine the CD4 and CD8 T cell repertoires specific for peptides of PSA and PSM in normal human male individuals, using short-term, peptide antigen-driven CD4 and CD8 T cell lines. We show that short-term, CD4 T cell lines derived from six HLA-DR4 individuals showed strong proliferative responses to six of 10 tested peptides of PSA, selected as to contain a DR4 binding motif. Short-term, CD8 T cell lines from three HLA-A1 individuals showed specific cytolytic activity for autologous targets loaded with five of five tested peptides of PSA and PSM, selected to possess an HLA-A1 binding motif. One of the peptides chosen is termed a 'dual-motif' peptide, as it encodes determinants for both CD4 and CD8 T cells. These results, indicating the existence of CD4 and CD8 T cells against determinants of the self proteins, PSA and PSM, in healthy male individuals reveal the potential of the T cell repertoire from the typical prostate cancer patient to eradicate prostate tumours upon being appropriately activated.

Securing the loop--historic review of the methods used for creating a loop colostomy

Loop transverse colostomy is a procedure that has been traditionally employed on a temporary basis for a number of indications, but, with improvement of intestinal suturing and stapling techniques, the applicability of this modality has become quite limited. This paper addresses the issue of securing the loop and traces the history of the development of this method to decompress the bowel, to divert the fecal stream, and to defunctionalize the distal colon.