Tissue-shrinkage Correction Factor in the Calculation of Prostate Cancer Volume

Abstract

Many studies that have calculated prostate cancer volumes from microscopic slides have used correction factors, ranging from 1.22 to 1.5, to compensate for tissue shrinkage during tissue processing. We undertook a study to measure tissue shrinkage directly because our experience suggested less shrinkage than that reported by others. Ten prostatectomy specimens were processed in a uniform manner. Multiple identical linear measurements were taken at four stages of processing: in the fresh state, following fixation, following processing, and from the microscopic slide. Linear shrinkage following fixation was minimal (4.1%) but increased to 14.5% following tissue processing. With rehydration and expansion on the flotation bath, tissues swelled so that net linear tissue shrinkage was 4.3%, and net volumetric tissue shrinkage was 12.4%, which translates into a correction factor for tissue shrinkage of 1.14. The following variables had no statistically significant effect on shrinkage: concentration of formalin, whole-mount versus quadrant sections, thickness of tissue slices, length of time in the alcohol dehydration steps, and temperature of the flotation bath over a range of 35 to 45 degrees C. This study suggests that (a) tissue-shrinkage correction factors that have been used in some previous studies may not be applicable for all laboratories because of interlaboratory variations in tissue-processing procedures or differences in measuring shrinkage; and (b) some calculated tumor volumes that have been used for prognostic thresholds may be high because of inflated tissue-shrinkage correction factors.

Difference between actual vs. pathology prostate weight in TURP and radical robotic-assisted prostatectomy specimen

“…The main action of these formaldehyde fixatives is to cross-link amino groups in proteins through the formation of methylene bridges (-CH 2 -), in the case of formaldehyde, or by a C5H10 cross-links in the case of glutaraldehyde. Formaldehyde will cause a significant amount of prostate tissue shrinkage by 4.1-4.5%, however we cannot find any scientifically valid result available regarding weight loss resulting by chemical fixation in prostatic specimens (2,3 Previous studies were conducted in animal organs (4) to estimate the effect of storage in formalin on organ weights; however, we can not find comparative papers for human prostate even after an extensive literature search.…”

Tissue Engineering of Human Heart Valve Leaflets: A Novel Bioreactor for a Strain-Based Conditioning Approach

“…A tissue volume shrinkage correction factor of 1.15 (1.046 linear shrinkage) was used to correct for the supposed loss of tissue volume due to tissue processing. 24 Stress-strain curves were obtained using an uniaxial tensile tester (Instron, Belgium, model 4411, equipped with a load cell of 10 N) with a constant strain rate of 1.7% per second. From the stress-strain curves, the ultimate tensile strength (UTS) was determined, as well as the strain at break.…”

A method for correlating in vivo prostate magnetic resonance imaging and histopathology using individualized magnetic resonance -based molds

“…21,22 This depends on the formalin concentration and the duration of the fixation. Our fixation procedure includes the immersion of the prostate specimen in formalin for approximately 2-24 h before slicing.…”