<p>Prostate cancer is the most common type of cancer in men in Europe and the USA. Some prostate tumours are regarded as stiffer than the surrounding normal tissue, and therefore it is of interest to be able to reliably measure prostate tissue stiffness. The methods presently used to detect prostate cancer are inexact, and new techniques are needed. In this licentiate thesis resonance sensor technology, with its ability to measure tissue stiffness, was applied to normal and cancerous prostate tissue.</p><p>A piezoelectric transducer element in a feedback system can be set to vibrate at its resonance frequency. When the sensor element contacts an object a change in the resonance frequency is observed, and this feature has been utilized in sensor systems to describe physical properties of different objects. For medical applications it has been used to measure stiffness variations due to various pathophysiological conditions.</p><p>An impression-controlled resonance sensor system was used to quantify stiffness in human prostate tissue in vitro using a combination of frequency change and force measurements. Measurements on prostate tissue showed statistically significant (p < 0.001) and reproducible differences between normal healthy tissue and tumour tissue when using a multivariate parameter analysis. Measured stiffness varied in both the normal tissue and tumour tissue group. One source of variation was assumed to be related to differences in tissue composition. Other sources of error could be uneven surfaces, different levels of dehydration of the prostates, and actual differences between patients.</p><p>The prostate specimens were also subjected to morphometric measurements, and the sensor parameter was compared with the morphology of the tissue with linear regression. In the probe impression interval 0.5–1.7 mm, the maximum coefficient of determination was R2 ≥ 0.60 (p < 0.05, n = 75). An increase in the proportion of prostate stones (corpora amylacea), stroma, or cancer in relation to healthy glandular tissue increased the measured stiffness. Cancer and stroma had the greatest effect on the measured stiffness. The deeper the sensor was pressed, the greater, i.e., deeper, volume it sensed.</p><p>It is concluded that prostate cancer increases the measured stiffness as compared with healthy glandular tissue, but areas with predominantly stroma or many stones could be more difficult to differentiate from cancer. Furthermore, the results of this study indicated that the resonance sensor could be used to detect stiffness variations in human prostate tissue in vitro, and especially due to prostate cancer. This is promising for the development of a future diagnostic tool for prostate cancer.</p>

Prostate cancer is the most common type of cancer in men in Europe and the USA. Some prostate tumours are regarded as stiffer than the surrounding normal tissue, and therefore it is of interest to be able to reliably measure prostate tissue stiffness. The methods presently used to detect prostate cancer are inexact, and new techniques are needed. In this licentiate thesis resonance sensor technology, with its ability to measure tissue stiffness, was applied to normal and cancerous prostate tissue. A piezoelectric transducer element in a feedback system can be set to vibrate at its resonance frequency. When the sensor element contacts an object a change in the resonance frequency is observed, and this feature has been utilized in sensor systems to describe physical properties of different objects. For medical applications it has been used to measure stiffness variations due to various pathophysiological conditions. An impression-controlled resonance sensor system was used to quantify stiffness in human prostate tissue in vitro using a combination of frequency change and force measurements. Measurements on prostate tissue showed statistically significant (p &lt; 0.001) and reproducible differences between normal healthy tissue and tumour tissue when using a multivariate parameter analysis. Measured stiffness varied in both the normal tissue and tumour tissue group. One source of variation was assumed to be related to differences in tissue composition. Other sources of error could be uneven surfaces, different levels of dehydration of the prostates, and actual differences between patients. The prostate specimens were also subjected to morphometric measurements, and the sensor parameter was compared with the morphology of the tissue with linear regression. In the probe impression interval 0.5–1.7 mm, the maximum coefficient of determination was R2 ≥ 0.60 (p &lt; 0.05, n = 75). An increase in the proportion of prostate stones (corpora amylacea), stroma, or cancer in relation to healthy glandular tissue increased the measured stiffness. Cancer and stroma had the greatest effect on the measured stiffness. The deeper the sensor was pressed, the greater, i.e., deeper, volume it sensed. It is concluded that prostate cancer increases the measured stiffness as compared with healthy glandular tissue, but areas with predominantly stroma or many stones could be more difficult to differentiate from cancer. Furthermore, the results of this study indicated that the resonance sensor could be used to detect stiffness variations in human prostate tissue in vitro, and especially due to prostate cancer. This is promising for the development of a future diagnostic tool for prostate cancer.

Prostate cancer is the most frequent type of cancer in men in Europe and the USA. The methods presently used to detect and diagnose prostate cancer are inexact, and new techniques are needed. Prostate tumours can be regarded as harder than the surrounding normal healthy glandular tissue, and therefore it is of interest to be able to reliably measure prostate tissue stiffness. In this dissertation the approach was to evaluate tactile resonance sensor technology and its ability to measure mechanical properties and to detect cancer in human prostate tissue. The tactile resonance sensor is based on a piezoelectric transducer element vibrating at its resonance frequency through a feedback circuit. A change in the resonance frequency is observed when the sensor contacts an object. This feature has been utilized to measure tissue stiffness variations due to various pathophysiological conditions. An impression-controlled tactile resonance sensor system was first used to quantify stiffness and evaluate performance on silicone. Then the sensor system was used on fresh human prostate tissue in vitro to measure stiffness using a combination of frequency change and force measurements. Significant differences in measured stiffness between malignant and healthy normal tissue were found, but there were large variations within the groups. Some of the variability was explained by prostate tissue histology using a tissue stiffness model. The tissue content was quantified at four depths in the tissue specimens with a microscope-image-based morphometrical method involving a circular grid. Numerical weights were assigned to the tissue data from the four depths, and the weighted tissue proportions were related to the measured stiffness through a linear model which was solved with a least-squares method. An increase in the proportion of prostate stones, stroma, or cancer in relation to healthy glandular tissue increased the measured stiffness. Stroma and cancer had the greatest effect and accounted for 90 % of the measured stiffness (45% and 45%, respectively). The deeper the sensor was pressed, the greater, i.e., deeper, volume it sensed. A sensing depth was extrapolated from the numerical weights for the measurements performed at different impression depths. Horizontal surface tissue variations were studied by altering the circular grid size relative to the contact area between the sensor tip and the tissue. The results indicated that the sensing area was greater than the contact area. The sensor registered spatial tissue variations. Tissue density-related variations, as measured by the frequency change, were weakly significant or non-significant. The measured force registered elastic-related tissue variations, to which stroma and cancer were the most important variables. A theoretical material-dependent linear relation was found between frequency change and force from theoretical models of frequency change and force. Tactile resonance sensor measurements on prostate tissue verified this at small impression depths. From this model, a physical interpretation was given to the parameters used to describe stiffness. These results indicate that tactile resonance sensor technology is promising for assessing soft tissue mechanical properties and especially for prostate tissue stiffness measurement with the goal of detecting prostate cancer. However, further studies and development of the sensor design must be performed to determine the full potential of the method and its diagnostic power. Preferably, measurements of tissue mechanical properties should be used in combination with other methods, such as optical methods, to increase the diagnostic power.

Abstract The principal aim of a population-based cross-sectional survey was to generate information on the lifetime occurrence of prostatitis in Finnish men and their exposure to the disease, and also on the influence of prostatitis-related fears and disturbances on their sexual life. A second aim was to develop and clinically validate a new diagnostic tool for differential diagnosis between the forms of chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS), especially between patients belonging to categories IIIA and IIIB in the new NIH (National Institutes of Health) clinical classification. Altogether 1832 men out of 2500 aged 20–59 years chosen randomly from the two most northerly provinces of Finland (Oulu and Lapland) participated in the epidemiological study, a response rate of 75%. The overall lifetime prevalence of prostatitis was 14.2%. The risk of having had the disease increased with age, being 1.7 times greater in the men aged 40–49 years than in those aged 20–39 years, and 3.1 times greater in those aged 50–59 years. More than a quarter of the 261 men who had or had had prostatitis symptoms (27%) suffered from them at least once a year, while 16% suffered from chronic prostatitis symptoms throughout the year. 63% of the men with prostatitis had their worst symptoms during the wintertime (November–march). 17% of the men with chronic prostatitis reported a constant fear of undetected prostate cancer. Erectile dysfunction was reported by 43% of the symptomatic men and decreased libido by 24%. Self-assessment of personality showed that the men with prostatitis were more often busy and nervous and had a meticulous attitude to life and problems than were the non-symptomatic men. 197 patients with chronic prostatitis/chronic pelvic pain syndrome participated in three clinical case-control studies during the years 1995–2000, at Oulu University Hospital, the District Hospital of Oulainen and Seinäjoki Central Hospital. The first prostatic tissue pressure measurement (PTPM) study included 34 patients and 9 controls. A novel method was developed to measure intraprostatic tissue pressure with a Stryker® intracompartmental pressure monitor. The PTPM showed a clear increase (p &lt; 0.001) in the patients with symptoms of prostatitis and benign prostatic enlargement (BPE) relative to the controls and the patients with BPE but without pain symptoms. The second PTPM study included 42 patients with chronic prostatitis symptoms without significant BPE and 12 new controls. Significantly higher pressure readings (p &lt; 0.001) were recorded at all three measurement points in the patients than in the controls. 48 new patients and 12 new controls were enrolled for the third PTPM study, the purpose of which was to confirm the results of the previous ones and to compare the prostatic tissue pressures of two clinical groups (IIIA and IIIB). The prostatic tissue pressure was again significantly higher in the patients with chronic prostatitis symptoms than in the controls (p &lt; 0.001). An interesting finding was that prostatitis patients belonging to clinical category IIIA had significantly higher tissue pressures (p &lt; 0.01) than those in category IIIB, probably reflecting more severe inflammation in the prostatic tissue. This new PTPM method provides a more precise and/or exact tool for differential diagnosis between the forms of pelvic pain and CP/CPPS.

Prostate cancer (PC) is the most common cancer in Sweden. Most patients have slow growing tumors that will not cause them any harm within their lifetime, but some have aggressive tumors and will die from their disease. The ability of current clinical practice to predict tumor behavior and disease outcome is limited leading to both over- and undertreatment of PC patients. The men who die from their disease are those that develop metastases. It is therefore of great value to find better and more sensitive prognostic techniques, so that metastatic spread can be detected (or predicted) at an early time point, and so that appropriate treatment can be offered to each subgroup of patients. The aim of this thesis was to investigate if, and by what means, highly aggressive prostate tumors influence extratumoral tissues such as the non-malignant parts of the prostate and regional lymph nodes (LN), and also if any of our findings could be of prognostic importance. Gene- and protein expression analysis were the main methods used to address these questions. Our research group has previously introduced the expression Tumor Instructed (Indicating) Normal Tissue (TINT), and we use the term TINT-changes when referring to alterations in non-malignant tissue due to the growth of a tumor nearby or elsewhere in the body. In the Dunning rat PC-model we found that MatLyLu (MLL)-tumors, having a high metastatic ability, caused pre-metastatic TINT-changes that differ from those caused by AT1-tumors who have low metastatic ability. Prostate-TINT surrounding MLL-tumors had elevated immune cell infiltration, and gene ontology enrichment analysis suggested that biological functions promoting tumor growth and metastasis were activated in MLL- while inhibited in AT1-prostate-TINT. In the regional LNs we found signs of impaired antigen presentation, and decreased quantity of T cells in the MLL-model. One of the downregulated genes in the MLL-LNs was Siglec1 (also known as Cd169), expressed by LN resident macrophages that are important for antigen presentation. When examining metastasis-free LN tissue from PC patients we found CD169 expression to be a prognostic factor for PC-specific survival, and reduced expression was linked to an increased risk of PC-specific death. Some of our findings in prostate- and LN-TINT could be seen already when the tumors were very small suggesting that differences in TINT-changes between tumors with different metastatic capability can be detected early in tumor progression. However, before coming of use in the clinic more research is needed to better define a suitable panel of prognostic TINT-factors as well as the right time window of when to use them. / Populärvetenskaplig sammanfattning Prostatacancer är den i särklass vanligaste cancerformen hos män i Sverige. De flesta patienter har en mycket långsamt växande tumör som inte orsakar dem några större besvär under deras livstid, men enbart i Sverige dör ca 2500 patienter/år av sjukdomen. Det är först vid uppkomst av metastaser som sjukdomen blir dödlig. Befintliga diagnos- och prognosmetoder är otillräckliga när det gäller att uppskatta och förutse tumörens aggressivitet och risk för att bilda metastaser. Detta gör att vissa patienter inte får tillräcklig behandling eller behandlas försent medan andra behandlas i onödan. Behovet av förbättrad diagnostik är därför stort. Om vi kan hitta markörer för potentiellt metastaserande sjukdom, och i bästa fall också behandla innan metastaser uppstår, skulle det förbättra chansen för överlevnad markant. För att kunna växa och spridas behöver en tumör inte bara förbereda närliggande vävnader utan förmodligen hela kroppen. Vår hypotes är att potentiell dödliga tumörer sannolikt är bättre på detta än mer ofarliga. Man vet från studier av andra cancerformer att farliga tumörer orsakar förändringar i det organ dit cancern senare sprids. Dessa förändringar sker för att de tumörceller som senare anländer ska kunna överleva, och processen har fått namnet pre-metastatisk nisch. Bl.a. har man sett att immunsystemet hämmas och nybildning av kärl ökar. Det är vanligt att metastaser uppstår i närliggande lymfkörtlar innan uppkomst av metastaser i andra organ. Dock är väldigt lite känt om pre-metastatiska förändringar i lymfkörtlar eftersom den forskning som hittills är gjord främst har tittat på andra organ. Inom prostatacancer finns det förvånande få studier av premetastatiska nischer överhuvudtaget, och man vet därför inte om de alls förekommer eller vilka förändringar som i så fall sker. Vår grupp har tidigare myntat uttrycket TINT som står för Tumor Instructed (Indicating) Normal Tissue (TINT är ett engelskt verb som betyder färga) och syftar på förändringar i normal vävnad som inducerats av tumören, dvs. att tumörer färgar av sig på omgivningen. Det kan vara förändringar i normal vävnad nära tumören, som i det här fallet resten av prostatan, eller i vävnad långt ifrån tumören som till exempel regionala lymfkörtlar, lungor och benmärg. Syftet med det här avhandlingsarbetet var att undersöka TINT-förändringar inducerade av aggressiv cancer och se om dessa skiljer sig från TINT-förändringar inducerade av mindre farliga tumörer, samt att utvärdera om någon TINT-förändring skulle kunna användas för att prognostisera vilka patienter som har hög risk att få metastaser. Vi har använt oss av en prostatacancer-modell i råtta där vi analyserat genoch proteinuttryck i pre-metastatiska regionala lymfkörtlar, tumörer och prostata-TINT (dvs. prostatavävnad utanför tumören). TINT-förändringar inducerade av MatLyLu (MLL), en tumör med hög metastaserande förmåga, jämfördes mot TINT-förändringar inducerade av AT1, en snabbväxande tumör men med låg förmåga att bilda metastaser. Vi kunde vi se flera skillnader mellan modellerna. Genuttrycket i MLL-prostata-TINT indikerade en aktivering av cellulära funktioner som visat sig stimulera tumörväxt och spridning såsom celldelning, viabilitet, migration, invasion, och angiogenes (nybildning av kärl). I AT1-prostata-TINT var genuttrycket kopplat till samma funktioner men verkade istället inhibera dessa. Genom att titta på vävnaderna i mikroskop kunde vi se att MLL-tumörer rekryterade färre T-celler (som har en viktig funktion i immunsvaret mot tumören), men istället fler makrofager och granulocyter till både tumören och prostata-TINT (dessa typer av immunceller har visats kunna hjälpa tumörer att växa och sprida sig). MLL-tumörer hade också fler blodkärl och lymfkärl strax utanför tumören. I de regionala lymfkörtlarna från djur med MLL-tumörer visade genuttrycket tecken på försämrad antigenpresentation, samt immunhämning och/eller induktion av immuntolerans. Immuntolerans innebär att immuncellen inte längre reagerar mot det specifika antigen den blivit tolerant emot. Detta är vanligt förekommande hos individer med cancer och är ett sätt för tumören att undkomma immunförsvaret. I vävnadsprover av lymfkörtlarna kunde vi se färre antigenpresenterande celler, och liksom i tumörerna fanns det färre T-celler i MLL-modellen, något vi kunde se redan när tumörerna var väldigt små. CD169 är ett protein som bl.a. uttrycks av sinus-makrofager i lymfkörtlar. Dessa makrofager har en central funktion i att aktivera ett tumör-specifikt immunsvar. I råttmodellen kunde vi se att regionala lymfkörtlar från djur med MLL-tumörer hade lägre nivåer av CD169 än regionala lymfkörtlar från djur med AT1-tumörer, och då antalet sinus-makrofager visat sig ha prognostiskt värde i t.ex. tjocktarmscancer, ville vi se om det kunde vara så även i prostatacancer. Därför kvantifierade vi uttrycket av CD169 i metastasfria regionala lymfkörtlar från prostatacancerpatienter och såg att låga nivåer av CD169 medförde en ökad risk för att dö i prostatacancer. Sammantaget tyder resultaten på att MLL-tumören jämfört med AT1- tumören bättre lyckas förbereda omgivande vävnad för att gynna tumörväxt och spridning, både lokalt i prostatan men också längre bort från tumören i de regionala lymfkörtlarna. Våra fynd stämmer väl överens med aktuell tumörbiologisk forskning om hur tumörer påverkar sin omgivning. Något som inte visats tidigare är att miljön utanför tumören verkar skilja sig drastiskt beroende på tumörens metastaserande förmåga, samt att dessa skillnader går att se relativt tidigt under sjukdomsförloppet och förmodligen även långt bort från tumören. Vi har också visat att särskilt aggressiv prostatacancer verkar inducera en pre-metastatisk nisch i tumördränerande lymfkörtlar likt det som beskrivits i andra modellsystem och i andra cancertyper, men hittills inte i prostatacancer. Fler studier behövs för att bättre karaktärisera de förändringar som en potentiellt dödlig prostatacancer orsakar i andra vävnader, och för att ta reda på hur denna kunskap kan användas för att förbättra diagnostik och behandling.