Prostate cancer volume correlates with stage, grade, and progression after prostatectomy. When tumor volume is measured planimetrically, results are multiplied by a correction factor to compensate for tissue shrinkage caused by processing. Injection of formalin into prostatectomy specimens was suggested for improved fixation. Our aim was to investigate how this affects the prostate volume. We studied 142 radical prostatectomy specimens. All prostates were immersed in 10% formalin. In 84 prostates (59%) we also injected 20 ml of formalin before routine fixation. The prostates were weighed unfixed after injection and after final fixation. The specimens were sliced and totally embedded. The transverse diameters of the prostates were measured on unfixed specimens and microscopic sections. The average weight loss after final fixation was 5.8 and 8.6% for formalin-injected specimens and standard-fixed specimens, respectively (p<0.001). However, when total shrinkage was estimated from the transverse diameters, there was no difference related to fixation technique (p=0.59). The average linear shrinkage was 4.5%, corresponding to a volume correction factor of 1.15. We conclude that formalin injection for fixation of prostate tissue does not influence tumor volume calculation compared to conventional fixation.

Our data suggest that PIM-1 overexpression in HGPIN may be an early event in the development of prostate malignancy. Additionally, PIM-1 expression provides supplementary information for distinguishing HGPIN from benign epithelium.

Microbeam irradiation is spatially fractionated radiation on a micrometer scale. Microbeam irradiation with therapeutic intent has become known as microbeam radiation therapy (MRT). The basic concept of MRT was developed in the 1980s, but it has not yet been tested in any human clinical trial, even though there is now a large number of animal studies demonstrating its marked therapeutic potential with an exceptional normal tissue sparing effect. Furthermore, MRT is conceptually similar to macroscopic grid based radiation therapy which has been used in clinical practice for decades. In this review, the potential clinical applications of MRT are analysed for both malignant and non-malignant diseases.

Heat shock proteins (HSPs) protect cells against stress-associated injury and are overexpressed in several malignant tumors. We aimed to investigate their value as prognostic markers in prostate cancer. A tissue microarray (TMA) was constructed of 289 prostate cancers from radical prostatectomy (RP) specimens with median follow-up of 48.9 months. Slides were immunostained for HSP27, HSP60 and HSP70. Intensity and extent of immunoreactivity (IR) and their product (IRp) was evaluated by two observers. The IRp of HSP27 and HSP60, but not of HSP70, significantly predicted biochemical recurrence (p=0.014, 0.034 and 0.160, respectively). Recurrence-free survival in patients with strong HSP27 and HSP60 staining was shorter than in those with weak expression (p=0.019 and 0.001, respectively). IRp of HSP27 and HSP60 correlated with Gleason score (p<0.01). HSP60 was an independent predictor of biochemical recurrence in multivariate analysis, including extraprostatic extension, margin status, seminal vesicle invasion and Gleason score. Weighted kappa for interobserver agreement of HSP27, HSP60 and HSP70 IR was 0.613-0.823 for intensity and 0.584-0.719 for IRp, but only 0.036-0.244 for extent, raising the question whether staining extent should be estimated on TMA. We conclude that HSP27 and HSP60 are predictors of biochemical recurrence after RP.