Early change in apparent diffusion coefficient as a predictor of response to neoadjuvant androgen deprivation and external beam radiation therapy for intermediate- to high-risk prostate cancer

AIM

To determine the role of serial apparent diffusion coefficient (ADC) as a biomarker for response to neoadjuvant androgen deprivation therapy (nADT) followed by external beam radiation therapy (EBRT) in intermediate- to high-risk prostate cancer (PCa) patients.

METHODS

This Health Insurance Portability and Accountability Act (HIPAA)-compliant, institutional review board (IRB)-approved prospective study included 12 patients with intermediate- to high-risk PCa patients prior to nADT and EBRT, who underwent serial serum prostate-specific antigen (PSA) and multiparametric prostate magnetic resonance imaging (mpMRI) at baseline (BL), 8-weeks after nADT initiation (time point [TP]1), 6-weeks into EBRT delivery (TP2), and 6-months after nADT initiation (TP3). Tumour volume (tVOL) and tumour and normal tissue ADC (tADC and nlADC) were determined at all TPs. tADC and nlADC dynamics were correlated with post-treatment PSA using Pearson's correlation coefficient. Paired t-tests compared pre/post-treatment ADC.

RESULTS

There was a sequential decrease in PSA at all TPs, reaching their lowest values at TP3 post-treatment completion. Mean tADC increased significantly from baseline to TP1 (917.8 ± 107.7 × 10-6 versus 1033.8 ± 139.3 × 10-6 mm2/s; p<0.01), with no subsequent change at TP2 or TP3. Both percentage and absolute change in tADC from BL to TP1 correlated with post-treatment PSA (r=-0.666, r=-0.674; p=0.02). Post-treatment PSA in good responders (<0.1 ng/ml) versus poor responders (≥ 0.1 ng/ml) was associated with a greater increase in tADC from BL to TP1 (169.2 ± 122.4 × 10-6 versus 22.9 ± 75.5 × 10-6 mm2/s, p=0.03).

CONCLUSION

This pilot study demonstrates the potential for early ADC metrics as a biomarker of response to nADT and EBRT in intermediate to high-risk PCA.

Analysis of the correlation between endorectal MRI response to neoadjuvant chemotherapy and biochemical recurrence in patients with high-risk localized prostate cancer

BACKGROUND

Intermediate end points are desirable to expedite the integration of neoadjuvant systemic therapy into the treatment strategy for high-risk localized prostate cancer. Endorectal magnetic resonance imaging at 1.5 Tesla (1.5T erMRI) response has been utilized as an end point in neoadjuvant trials but has not been correlated with clinical outcomes.

METHODS

Data were pooled from two trials exploring neoadjuvant chemotherapy in high-risk localized prostate cancer. Trial 1 explored docetaxel for 6 months and Trial 2 explored docetaxel plus bevacizumab for 4.5 months, both before radical prostatectomy. erMRI was done at baseline and end of chemotherapy. 1.5T erMRI response, based upon T2W sequences, was recorded. Multivariable Cox regression was undertaken to evaluate the association between clinical parameters and biochemical recurrence.

RESULTS

There were 53 evaluable patients in the combined analysis: 20 (33%) achieved a PSA response, 16 (27%) achieved an erMRI partial response and 24 (40%) achieved an erMRI minor response. Median follow-up was 4.2 years, and 33 of 53 evaluable (62%) patients developed biochemical recurrence. On multivariable analysis, PSA response did not correlate with biochemical recurrence (hazard ratio=0.58, 95% confidence interval (CI) 0.25-1.33) and paradoxically erMRI response was associated with a significantly shorter time to biochemical recurrence (hazard ratio=2.47, 95% CI 1.00-6.13).

CONCLUSIONS

Response by 1.5T erMRI does not correlate with a decreased likelihood of biochemical recurrence in patients with high-risk localized prostate cancer treated with neoadjuvant docetaxel and may be associated with inferior outcomes. These data do not support the use of 1.5T erMRI response as a primary end point in neoadjuvant chemotherapy trials.

Case report. PET/CT appearance of desmoid tumour of the chest wall

Desmoid tumours are rare, poorly circumscribed tumours that have a firm consistency and, although benign, have a remarkable tendency to infiltrate into surrounding structures. Extra-abdominal desmoid tumours involve mainly the extremities or the chest wall and are usually managed by wide radical resection. Moreover, desmoid tumours involving the chest wall are locally aggressive tumours with a high recurrence rate. We report a case of a pathologically proven desmoid tumour of the chest wall in a patient with a history of bilateral breast cancer and oesophageal cancer. We discuss the imaging appearances of this tumour on positron emission tomography combined with computed tomography (PET/CT) and magnetic resonance imaging.

A phase II study of neoadjuvant chemotherapy with docetaxel and bevacizumab in patients (pts) with high-risk localized prostate cancer: A Prostate Cancer Clinical Trials Consortium trial

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Background: Treatment options for high-risk localized prostate cancer remain inadequate, with the majority of pts relapsing despite surgery or radiation therapy. We conducted a phase II multicenter trial of neoadjuvant docetaxel and bevacizumab prior to radical prostatectomy in pts with high risk localized prostate cancer. Methods: Eligibility included any of the following: PSA > 20 ng/ml or PSA velocity > 2 ng/ml/yr, cT3 disease, any biopsy Gleason 8–10, Gleason 7 with T3 disease by endorectal (er) MRI. Also, >50% biopsy cores involved and either Gleason 7 or PSA >10 or cT2 disease were eligible. Pts were treated with docetaxel 70 mg/m2 q 3weeks x 6 cycles and bevacizumab 15 mg/m2 q 3 weeks x 5 cycles. The primary endpoint was erMRI partial response (PR, defined here as >50% decrease in tumor volume) in a single target lesion after chemotherapy. Results: 42 pts were registered and treated with 220 cycles so far. Median age was 55 yrs (range 41–67). Median Gleason score was 8 (69% with Gleason 8–10 cancer). Median PSA was 10.5 ng/ml (range 2.1–72.5). Clinical stage was T2 in 46% and T3 in 32%. Of 23 evaluable pts to date, the median decline in the maximal tumor volume by erMRI was -45% (range -84% to 110%). 9/23 (39%) patients had PR, and only 1 pt had radiographic progression. Any PSA decline was noted in 22/34 (65%) evaluable pts, with 18% having a >50% decline. Treatment was well-tolerated: 2 pts had grade 3 allergic reactions requiring discontinuation, 3 had febrile neutropenia and 1 had grade 3 hyperglycemia. Mild fatigue was common. Only 1 pt stopped treatment because of a rising PSA. To date, 31 pts have had radical prostatectomy. One had intraoperative bladder neck injury and was treated instead with radiation + hormone therapy. A second pt had an intraoperative rectal injury but completed surgery. Conclusions: Neoadjuvant docetaxel and bevacizumab demonstrates clinical evidence of activity in men with high-risk localized prostate cancer, with a 39% PR rate by erMRI and PSA declines noted in 65%. Treatment was well-tolerated. The study is ongoing and updated data on response, toxicity and pathology will be presented.

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Taurine and vitamin C modify monocyte and endothelial dysfunction in young smokers

BACKGROUND

Endothelial dysfunction initiated by monocyte-endothelial interactions has previously been observed in many vasculopathies, including chronic cigarette smoking. Taurine, a semiessential amino acid, and vitamin C, a naturally occurring antioxidant, have previously been shown to have endothelial protective effects when exposed to proinflammatory insults. Therefore, we hypothesized that taurine and vitamin C would restore endothelial function in young smokers by modifying monocyte-endothelial interactions.

METHODS AND RESULTS

Endothelial-dependent vasodilatation was assessed in vivo using duplex ultrasonography, and monocyte-endothelial interactions were assessed in vitro using endothelial cell culture (human umbilical vein endothelial cells [HUVECs]) with monocyte-conditioned medium (MCM). Endothelial-dependent vasodilatation was significantly impaired in young smokers compared with nonsmokers. Pretreatment of young smokers for 5 days with 2 g/d vitamin C and, more significantly, with 1.5 g/d taurine attenuated this response. MCM taken from smokers impaired the release of nitric oxide and increased the levels of endothelin-1 release from HUVECs. When HUVECs were cultured with MCM from smokers who had been treated with taurine, the levels of nitric oxide and endothelin-1 returned toward control levels. This was attributed to an upregulation in endothelial nitric oxide synthase expression.

CONCLUSIONS

These observations suggest that taurine supplementation has a beneficial impact on macrovascular endothelial function, and an investigation of its effect on altered endothelial function in dyslipidemic states is warranted.