Use of modifying phrases in surgical pathology reports: is there a different understanding between pathologists and treating physicians?

When not all the histopathologic and clinical features necessary for a pathology diagnosis are present in a particular specimen, pathologists may use modifying phrases to convey various degrees of certainty, e.g., "consistent with…" and "suggestive of…." However, it is unclear whether pathologists use such phrases consistently or whether treating physicians fully understand their intended meaning. A questionnaire concerning six common modifying phrases ("consistent with, suggestive of, suspicious for, highly consistent with, highly suggestive of, some features of") was sent to all physicians from a single institution who either issued or routinely received surgical pathology reports. Physicians were asked to rank their understanding of each phrase on a printed scale between 1 ("no evidence of") and 10 ("diagnostic of"). One hundred sixty physicians (74.3%) responded. Despite wide variation, there was a hierarchy (from more to less diagnostic): highly consistent > highly suspicious > consistent > suspicious > suggestive > some features (p < 1 × 10^-7). There were no significant differences between pathologists and treating physicians (p = 0.72) or attendings and residents (p = 0.9). Pathologists and treating physicians share an overall common understanding of their hierarchical relationship, albeit with wide ranges. Based upon our results, we propose to use only three qualifying phrases to convey the degree of certainty for a particular diagnosis: "suggestive of" (> 25 ≤ 50% certainty), "suspicious for" (> 50 ≤ 75%), and "consistent with" (> 75%). The phrase "no evidence of" should probably be used only when there is ≤ 5% confidence in a diagnosis, and conversely, "diagnostic of" should probably be used only when there is ≥ 95% confidence in a diagnosis.

Extent of High-Grade Prostatic Adenocarcinoma in Multiparametric Magnetic Resonance Imaging-Targeted Biopsy Enhances Prediction of Pathologic Stage

CONTEXT.—

Multiparametric magnetic resonance imaging (mpMRI) of prostate with targeted biopsy has enhanced detection of high-grade prostatic adenocarcinoma (HG PCa). However, utility of amount of HG PCa (Gleason pattern 4/5) in mpMRI-targeted biopsies versus standard 12-core biopsies in predicting adverse outcomes on radical prostatectomy (RP) is unknown.

OBJECTIVE.—

To examine the utility of amount of HG PCa in mpMRI-targeted biopsies versus standard 12-core biopsies in predicting adverse RP outcomes.

DESIGN.—

We performed a retrospective review of prostate biopsies, which had corresponding RP, 1 or more mpMRI-targeted biopsy, and grade group 2 disease or higher. For the 169 cases identified, total millimeters of carcinoma and HG PCa, and longest length HG PCa in a single core were recorded for 12-core biopsies and each set of mpMRI-targeted biopsies. For RP specimens, Gleason grade, extraprostatic extension, seminal vesicle involvement, and lymph node metastasis were recorded. The main outcome studied was prostate-confined disease at RP. A logistic regression model was used to test which pre-RP variables related to this outcome.

RESULTS.—

Univariate analysis showed significant associations with adverse RP outcomes in 5 of 8 quantifiable variables; longest millimeter HG PCa in a single 12-core biopsy, highest grade group in any core, and total millimeter HG in mpMRI-targeted biopsies showed no statistical association (P = .54, P = .13, and P = .55, respectively). In multivariate analysis, total millimeter carcinoma in all cores, highest GrGrp in any core, and longest millimeter HG PCa in a single mpMRI-targeted core provided additional predictive value (P < .001, P = .004, and P = .03, respectively).

CONCLUSIONS.—

Quantitation of HG PCa in mpMRI-targeted biopsies provides additional value over 12-core biopsies alone in predicting nonorgan confined prostate cancer at RP. Linear millimeters of HG PCa in mpMRI-targeted biopsies is a significant parameter associated with higher pathologic stage and could be of value in risk models.

The Importance of Tumor Length in Needle Biopsies of the Prostate

OBJECTIVES

To form a composite predictor variable that combines the effects of tumor length, serum prostate-specific antigen (PSA), and International Society of Urologic Pathologists (ISUP) grade on the observation of adverse prostatectomy pathology.

METHODS

Logistic regression analysis was used to demonstrate how tumor length, serum PSA, and ISUP grade related to adverse prostatectomy results and to derive weighting factors for a composite variable, cx.

RESULTS

The composite variable, cx, relates closely to adverse prostatectomy results as well as to observed PSA failure.

CONCLUSIONS

The composite variable cx uses preoperative information that may allow the sorting of patients into low, intermediate, and high risk for adverse outcomes after prostatectomy.

The Calculus of Serum PSA

OBJECTIVES

To review the mathematics of kinetic changes in serum prostate-specific antigen (PSA) and to use a compartmental model to derive a new kinetic measure, alpha.

METHODS

The calculus of kinetic measures of PSA changes with time is presented, and a compartmental model is then used to derive alpha of serum PSA. Alpha is then tested for prognostic importance in 119 men who underwent prostatectomy.

RESULTS

The percentage of tumor in the prostate is closely related to alpha and to tumor length in diagnostic needle biopsies, but not to tumor grade. The presence of adverse pathology in the prostatectomy specimens (positive margins or T3 stage) is significantly associated with alpha, but not to tumor length or grade.

CONCLUSIONS

The derived kinetic parameter, alpha, shows promise as a preoperative prognostic parameter, and may help sort patients into those with low vs high probability for adverse pathology features in the prostatectomy specimens.

Serum Prostate-Specific Antigen (PSA) Concentration, PSA Mass, and Obesity: A Mathematical Analysis

OBJECTIVES

To provide a mathematical background for understanding the phenomenon of analyte hemodilution using a kinetic analysis.

METHODS

The first assumption for this analysis is that change in concentration of any analyte, such as prostate-specific antigen (PSA), is due to the flux of the analyte from an organ into the blood minus its flux from the blood. What results is a relatively simple differential equation that emphasizes the importance of plasma volume, organ mass, and two rate constants.

RESULTS

The analyses demonstrate how serum PSA can be affected by plasma volume as well as body mass and how hemodilution due to obesity can be at least partly corrected for by expressing PSA in units of total mass or total mass density.

CONCLUSIONS

At a time when obesity is prevalent, expressing analytes in units of total mass may make them relate more closely to disease status and prognosis.

Defining Papillary Carcinoma of the Thyroid: A Short Review and Analysis

OBJECTIVES

To review how changes in the pathologic definitions for papillary tumors of the thyroid during recent decades have affected outcomes for patients with these tumors.

METHODS

Forty-nine previous reports or studies involving collectively 53,606 patients were reviewed, and new analyses were performed on the data to include analyses of agreement, incidence, survival, and diagnostic categories.

RESULTS

The past emphasis on cytologic features to define papillary tumors has not resulted in ideal pairwise agreement between pathologists and has produced incidence and survival data suggesting overdetection and overdiagnosis. Most recently, tissue patterns have been reemphasized.

CONCLUSIONS

With the recent reemphasis on diagnostic tissue patterns (over cytologic criteria), agreements between pathologists for the diagnosis of papillary tumors should improve, and the incidence of papillary carcinoma should decline. Nevertheless, updated survival analyses demonstrate excellent long-term survival for most of those diagnosed with papillary carcinomas.

Gleason Grading, Biochemical Failure, and Prostate Cancer-Specific Death

OBJECTIVES

To examine the relationship between the recently defined Gleason grade groups and prostate cancer-specific mortality.

METHODS

If the probability of prostate cancer-specific death is symbolized as P(PSD), the probability of biochemical failure is symbolized as P(BF), and the probability of prostate cancer-specific death after biochemical failure is symbolized as P(PSD | BF), then the rules of probability provide a way to estimate P(PSD) as P(PSD) = P(PSD | BF) * P(BF) Using this model and data from the literature for P(PSD | BF) and P(BF), I estimate here values of P(PSD) for the five newly described Gleason grade groups.

RESULTS

The expected probability of prostate cancer- specific death is closely related to the new Gleason grade groups and ranges from a low of 0.014 for grade group 1 to a high of 0.15 for grade group 5.

CONCLUSIONS

Although using the original study patient population may require years of additional follow-up to examine prostate cancer-specific mortality, the evidence available now indicates that these new Gleason grade groups relate to prostate cancer-specific mortality.

A Review of Outcomes for Colorectal Adenomas

OBJECTIVES

Using data from former reports, this study reviews and analyzes the outcomes of tumor recurrence, tumor progression, and tumor-specific survival of patients with colorectal adenomas.

METHODS

Data were collected from 32 longitudinal studies of outcomes after the first diagnosis of colorectal adenoma and collected as individual patient results, that is, as failure times from the first tumor to the three outcomes. Altogether, there were 45,286 patients, including 22,148 for the outcome of additional adenomas, 23,796 for the outcome of progression to invasive carcinoma, and 2,602 for the outcome of disease-specific survival (some patients were available for more than one outcome).

RESULTS

In these data, the mean time to additional adenomas was 6 years, the mean time to invasive carcinoma was 15.9 years, and the mean tumor-specific survival time was 21.9 years.

CONCLUSIONS

Although greater than 50% of those with colorectal adenomas will have additional adenomas, few progress to invasive tumor or die of colorectal cancer.

A Review of Outcomes for Stage Ta Bladder Tumors

OBJECTIVES

Using data from former reports, this study reviews and analyzes the outcomes of tumor recurrence, tumor progression, and tumor-specific survival of patients with stage Ta bladder tumors.

METHODS

Data were collected from 19 longitudinal studies of outcomes after the first diagnosis of tumor and collected as individual patient results, that is, as failure times from the first tumor to any of the three outcomes. Altogether, there were 14,252 patients, including 4,050 for the outcome of tumor recurrence, 2,937 for the outcome of tumor progression, and 11,595 for the outcome of disease-specific survival (some patients were available for more than one outcome).

RESULTS

In these data, the mean time to additional tumors was 7.8 years, the mean time to an invasive tumor was 19.5 years, and the mean tumor-specific survival time was 27.2 years. All three outcomes were significantly related to the 2004 World Health Organization (WHO) tumor grades.

CONCLUSIONS

Although greater than 50% of those with stage Ta bladder tumors have additional bladder tumors, approximately 80% appear to follow a benign course without developing invasive tumors or dying of bladder cancer. The 2004 WHO grading scheme accounts for some but not all of the prognostic information.

Detection of Occult Micrometastases in Patients With Clinical Stage I Non-Small-Cell Lung Cancer: A Prospective Analysis of Mature Results of CALGB 9761 (Alliance)

PURPOSE

Outcomes after resection of stage I non-small-cell lung cancer (NSCLC) are variable, potentially due to undetected occult micrometastases (OM). Cancer and Leukemia Group B 9761 was a prospectively designed study aimed at determining the prognostic significance of OM.

MATERIALS AND METHODS

Between 1997 and 2002, 502 patients with suspected clinical stage I (T1-2N0M0) NSCLC were prospectively enrolled at 11 institutions. Primary tumor and lymph nodes (LNs) were collected and sent to a central site for molecular analysis. Both were assayed for OM using immunohistochemistry (IHC) for cytokeratin (AE1/AE3) and real-time reverse transcriptase polymerase chain reaction (RT-PCR) for carcinoembryonic antigen.

RESULTS

Four hundred eighty-nine of the 502 enrolled patients underwent complete surgical staging. Three hundred four patients (61%) had pathologic stage I NSCLC (T1, 58%; T2, 42%) and were included in the final analysis. Fifty-six percent had adenocarcinomas, 34% had squamous cell carcinomas, and 10% had another histology. LNs from 298 patients were analyzed by IHC; 41 (14%) were IHC-positive (42% in N1 position, 58% in N2 position). Neither overall survival (OS) nor disease-free survival was associated with IHC positivity; however, patients who had IHC-positive N2 LNs had statistically significantly worse survival rates (hazard ratio, 2.04, P = .017). LNs from 256 patients were analyzed by RT-PCR; 176 (69%) were PCR-positive (52% in N1 position, 48% in N2 position). Neither OS nor disease-free survival was associated with PCR positivity.

CONCLUSION

NSCLC tumor markers can be detected in histologically negative LNs by AE1/AE3 IHC and carcinoembryonic antigen RT-PCR. In this prospective, multi-institutional trial, the presence of OM by IHC staining in N2 LNs of patients with NSCLC correlated with decreased OS. The clinical significance of this warrants further investigation.

Probabilistic issues with sentinel lymph nodes in malignant melanoma

OBJECTIVES

To address issues of probability for sentinel lymph node results in melanoma and provide details about the probabilistic nature of the numbers of sentinel nodes as well as to address how these issues relate to tumor thickness and patient outcomes.

METHODS

Analysis of the probability of observing sentinel node metastases uses the discrete exponential probability distribution to address the number of observed positive sentinel nodes. In addition, mathematical functions derived from survival analysis are used. Data are then chosen from the literature to illustrate the approach and to derive results.

RESULTS

Observations about the numbers of positive and negative sentinel nodes closely follow discrete exponential probability distributions, and the relationship between the probability of a positive sentinel node and tumor thickness follows closely a function derived from survival analysis. Sentinel node results relate to tumor thickness as well as to the total number of nodes harvested but fall short of identifying all those who eventually develop metastatic melanoma.

CONCLUSIONS

Probability analyses provide useful insight into the success and failure of the sentinel node biopsy procedure in patients with melanoma.

Disparate results between proliferation rates of surgically excised prostate tumors and an in vitro bioassay using sera from a positive randomized controlled trial

In vitro bioassay has been used extensively to test the effects of culturing cancer cells in sera from humans participating in dietary interventions, i.e, studies of modified intake of nutrients for the purpose of reducing cancer risk or progression. It has been hypothesized that cell proliferation rates determined by the in vitro bioassay indicate whether modification of dietary intake could decrease cancer cell growth in vivo. It has been suggested, however, that the in vitro bioassay may not correlate with tumor cell proliferation rates in prostate cancer. We investigated the concordance of cell proliferation rates from surgically excised prostate tumor tissue with the in vitro bioassay using sera from matched patients. We used samples from an earlier randomized clinical trial that showed that supplementation with flaxseed significantly inhibited prostate cancer cell proliferation rates in vivo as indicated by Ki67 staining in tumor specimens. Proliferation rates of LNCaP, DU145 and PC3 cell lines cultured in 10% human sera from participants in the flaxseed trial were determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Spearman's Rho correlation coefficients (ρ) indicated no association between Ki67 staining in prostate tumors and the in vitro bioassay for the three cell lines. These disparate findings suggest that the in vitro bioassay may not provide an accurate assessment of the environment in vivo.

A review of survival in mycosis fungoides

OBJECTIVES

The objectives of this study are to review prior publications of survival for patients with mycosis fungoides (MF), to perform some analyses on the consolidated data, and then to consider the implications of the results.

METHODS

The data for this study comprise 18 survival curves derived from seven prior publications of long-term survival in relatively large series of patients with MF. Altogether, the study uses results from over 5,000 patients. To examine fatality, the study uses hazard functions derived from the survival curves.

RESULTS

The analyses demonstrate significant variability in survival between different groups who have studied MF, and the results document that for most patients the diagnosis of MF has little impact on fatality.

CONCLUSIONS

Although MF is considered a cutaneous lymphoma, that is, a malignancy, it may be time to reconsider low stages of MF as precursors to malignancy analogous to the precursors to malignancies of other types or organs.

A probabilistic analysis of mitotic counts in melanoma

OBJECTIVES

Mitotic counts in melanoma are important and have now become part of the staging of this tumor. Yet, this change was largely based on studies that evaluated the mitotic counts in a limited fashion. Because counts of things with a microscope are often distributed as a Poisson random variable, the major goal of this study was to uncover the probabilistic nature of mitotic counts in melanoma.

METHODS

Specifically, a general double Poisson model was applied to mitotic counts in 53 cutaneous melanomas representing both thin and thick tumors.

RESULTS

The general double Poisson probability model fit the data well. A single Poisson function was sufficient for 46 of the 53 study cases, and two Poisson functions were required for seven cases because of tissue heterogeneity. Furthermore, the success of the model implied that there is a high probability for false-negative mitotic counts, especially in thin melanomas, and that the "hot" spot methodology introduces bias.

CONCLUSIONS

Mitotic counts in melanomas are a probabilistic phenomenon closely related to the Poisson probability distribution, and this factor needs to be considered when using mitotic counts for staging and prognosis in melanoma.

Revisiting overdiagnosis and fatality in thyroid cancer

OBJECTIVES

To examine the rates of incidence and fatality in cohorts of patients diagnosed with thyroid cancer from 1975 to 1999.

METHODS

This study uses National Cancer Institute's Surveillance, Epidemiology and End Results data and derives hazard functions in order to examine the fatality in thyroid cancer.

RESULTS

The study documents forms of rapidly evolving and fatal tumors as well as forms of tumor that evolve more slowly to cause death. It demonstrates that the incidences of nonfatal forms of thyroid cancer have risen dramatically in the years from 1975 to 1999-mostly due to papillary carcinomas-but that the incidences of fatal forms of thyroid cancer have remained nearly constant.

CONCLUSIONS

The results of this study support the notion that many thyroid cancers are part of a reservoir of nonfatal tumors that are increasingly being overdetected and overdiagnosed.

Epidermal dynamics and patterns of intraepidermal melanoma

BACKGROUND

Dermatopathologists know that the epidermis represents a dynamic compartment and that its cells mature from the basal layer to the skin surface in approximately 45 days. What may seem intuitive - but not obvious - is that the dynamics of the epidermis can affect the patterns of melanoma cells within the epidermis. Here this conjecture is explored with an abstract, theoretical model.

METHODS

To control the independent effects of epidermal replacement velocity and thickness as well as rate of melanoma cell penetration of the epidermis, an abstraction of the epidermis was created and simulated via computer.

RESULTS

Simulated plots of the epidermis show that the number and pattern of melanoma cells in the epidermis is affected by the probability of melanoma cells entering the epidermis, by the velocity of epidermal replacement and by epidermal thickness.

CONCLUSION

This analysis suggests that the dynamics of the epidermis are sufficient to affect the patterns of melanoma cells within the epidermis.

Flaxseed-derived enterolactone is inversely associated with tumor cell proliferation in men with localized prostate cancer

Enterolactone and enterodiol, mammalian lignans derived from dietary sources such as flaxseed, sesame seeds, kale, broccoli, and apricots, may impede tumor proliferation by inhibiting activation of nuclear factor kappa B (NFκB) and vascular endothelial growth factor (VEGF). We examined the associations between urinary enterolactone and enterodiol with prostatic tumor expression of NFκB, VEGF, and Ki67 among 147 patients with prostate cancer who participated in a presurgical trial of flaxseed supplementation (30 g/day) for ~30 days. Urinary enterolignans and tissue biomarkers were determined by high-performance liquid chromatography and immunohistochemistry, respectively. After supplementation, we observed significant correlations between intakes of plant lignan and urinary concentrations of total enterolignans (ρ=0.677, P<.0001), enterolactone (ρ=0.676, P<.0001), and enterodiol (ρ=0.628, P<.0001). Importantly, we observed that total urinary enterolignans and enterolactone were significantly and inversely correlated with Ki67 in the tumor tissue (ρ=-0.217, P=.011, and ρ=-0.230, P=.007, respectively), and a near-significant inverse association was observed for enterodiol (ρ=-0.159, P=.064). An inverse association was observed between enterolactone and VEGF (ρ=-0.143, P=.141), although this did not reach statistical significance. We did not observe an association between enterolignans and NFκB. In conclusion, flaxseed-derived enterolignans may hinder cancer cell proliferation via VEGF-associated pathways.

Intratumoral inflammation is associated with more aggressive prostate cancer

PURPOSE

Inflammation may play a role in the development and progression of many cancers, including prostate cancer. We sought to test whether histological inflammation within prostate cancer was associated with more aggressive disease.

METHODS

The slides of prostatectomy specimens were reviewed by a board-certified pathologist on 287 men from a Veterans Affairs Medical Center treated with radical prostatectomy from 1992 to 2004. The area with the greatest tumor burden was scored in a blinded manner for the degree of inflammation: absent, mild, or marked. We used logistic and Cox proportional hazards regression analysis to examine whether categorically coded inflammation score was associated with adverse pathology and biochemical progression, respectively.

RESULTS

No inflammation was found in 49 men (17%), while 153 (53%) and 85 (30%) had mild and marked inflammation. During a median follow-up of 77 months, biochemical recurrence occurred among 126 (44%) men. On multivariate analysis, more inflammation was associated with greater risk of positive margins, capsular penetration, and seminal vesicle invasion (all p < 0.05). Marked inflammation was associated with increased PSA recurrence risk when adjusting for preoperative features only (HR 2.08, 95% CI 1.02-4.24), but not after adjusting for pathologic features.

CONCLUSIONS

Inflammation within prostate cancer was associated with more advanced disease, although it is unclear whether aggressive disease caused increased inflammation or inflammation caused aggressive disease.

Prostatic alpha-linolenic acid (ALA) is positively associated with aggressive prostate cancer: a relationship which may depend on genetic variation in ALA metabolism

Previous observational studies have reported associations between prostate cancer and alpha-linolenic acid (ALA). However, few investigations have been able to study this relationship prospectively and in well-controlled settings. Moreover, no studies have determined whether single nucleotide polymorphisms (SNPs) that influence ALA metabolism are associated with this common cancer. The purpose of this study was to explore associations between prostatic levels of ALA, SNPs and prostate cancer-specific biomarkers in samples collected from a previous randomized clinical trial conducted using a presurgical model and which tested the effects of flaxseed supplementation, a rich source of ALA, prior to prostatectomy (n = 134). Serum prostate-specific antigen (PSA) was determined and immunohistochemistry was used to assess tumor proliferation rate (Ki67). Prostatic ALA was determined with gas chromatography. Seven previously identified SNPs associated with delta-6 desaturase activity (rs99780, rs174537, rs174545, rs174572, rs498793, rs3834458 and rs968567) were tested for associations with prostatic ALA, PSA and Ki67. Despite consuming seven times more ALA per day, men in the flaxseed arm had similar amounts of prostatic ALA relative to men not consuming flaxseed. In unadjusted analysis, there were significant positive associations between prostatic ALA and PSA (ρ = 0.191, p = 0.028) and Ki67 (ρ = 0.186, p = 0.037). After adjusting for covariates (flaxseed, age, race, BMI and statin-use) the association between ALA and PSA remained (p = 0.004) but was slightly attenuated for Ki67 (p = 0.051). We did not observe associations between any of the SNPs studied and prostatic ALA; however, in models for PSA there was a significant interaction between rs498793 and ALA and for Ki67 there were significant interactions with ALA and rs99780 and rs174545. Independent and inverse associations were observed between rs174572 and Ki67. This study provides evidence that prostatic ALA, independent of the amount of ALA consumed, is positively associated with biomarkers of aggressive prostate cancer and that genetic variation may modify this relationship.

Abstract A95: Prostatic alpha-linolenic acid (ALA) is positively associated with aggressive prostate cancer: A relationship which may depend on genetic variation in ALA metabolism

Previous observational studies have reported associations between prostate cancer and alpha-linolenic acid (ALA), the most commonly consumed omega-3 polyunsaturated fatty acid in a Western diet. However, few investigations have been able to study this relationship prospectively and in well-controlled settings. Moreover, to date, no studies have determined whether single nucleotide polymorphisms (SNPs) that influence ALA metabolism are associated with this common cancer. The purpose of this study was to explore associations between prostatic levels of ALA, SNPs and prostate cancer-specific biomarkers in samples collected from a previous randomized clinical trial conducted using a presurgical model and which tested the effects of 30 g/d of flaxseed, a rich source of ALA, for ∼30 days prior to prostatectomy (n=134). Serum prostate-specific antigen (PSA) was determined and immunohistochemistry was used to assess tumor Ki67 staining (proliferation rate). Prostatic ALA was determined with gas chromatography. Seven previously identified SNPs (rs99780, rs174537, rs174545, rs174572, rs498793, rs3834458 and rs968567) were tested for associations with prostatic ALA, PSA and Ki67. Despite consuming nearly seven times more ALA per day, men in the flaxseed arm had similar amounts of prostatic ALA relative to men not consuming flaxseed [median (range) 0 (0-9.41) versus 0 (0-0.85), p=0.296. In unadjusted analysis, there were significant positive associations between prostatic ALA and PSA (ρ=0.191, p=0.028) and Ki67 (ρ=0.186, p=0.037). After adjusting for covariates (flaxseed, age, race, BMI and statin-use) the association between ALA and PSA remained (p=0.004) but was slightly attenuated for Ki67 (p=0.051). We did not observe associations between any of the SNPs studied and prostatic ALA; however, in models for PSA there was a significant interaction between rs498793 and ALA (p=0.017) and for Ki67 there were significant interactions with ALA and rs99780 (p=0.033) and rs174545 (p=0.047). An independent association between rs174572 and Ki67 was observed (p=0.007). This study provides evidence that prostatic ALA, independent of the amount of ALA consumed, is positively associated with biomarkers of aggressive prostate cancer. This study also observed for the first time that SNPs related to ALA metabolism may modify the association between ALA and prostate cancer.

Citation Format: Maria Azrad, Robert W. Hardy, Wendy Demark-Wahnefried, Kui Zhang, Robin T. Vollmer, John Madden, Thomas Polascik, Denise C. Snyder, Mack T. Ruffin, Judd Moul, Dean Brenner. Prostatic alpha-linolenic acid (ALA) is positively associated with aggressive prostate cancer: A relationship which may depend on genetic variation in ALA metabolism. [abstract]. In: Proceedings of the Eleventh Annual AACR International Conference on Frontiers in Cancer Prevention Research; 2012 Oct 16-19; Anaheim, CA. Philadelphia (PA): AACR; Cancer Prev Res 2012;5(11 Suppl):Abstract nr A95.

The dynamics of death in prostate cancer

The hazard function provides the instantaneous probability of death (or other key end point) at various times after diagnosis. Unlike the survival curve, the hazard function illustrates graphically or through calculations when deaths are common or uncommon. In this study, hazard functions were derived for prostate cancer by using survival data on large numbers of patients with prostate cancer with data in the Surveillance, Epidemiology and End Results (SEER) database. The results demonstrate a form of prostate cancer that rapidly evolves to cause death within 5 years, and this form of tumor is only partly identified by routine prognostic variables such as serum prostate-specific antigen (PSA) level, histologic grade, and quantity of tumor. The results also validate the presence of a reservoir of nonfatal prostate cancers that have increased rapidly during the PSA era, and they demonstrate that the incidence of fatal prostate cancers has declined.

Effect of low-fat diets on plasma levels of NF-κB-regulated inflammatory cytokines and angiogenic factors in men with prostate cancer

Diet, nutritional status, and certain dietary supplements are postulated to influence the development and progression of prostate cancer. Angiogenesis and inflammation are central to tumor growth and progression, but the effect of diet on these processes remains uncertain. We explored changes in 50 plasma cytokines and angiogenic factors (CAF) in 145 men with prostate cancer enrolled in a preoperative, randomized controlled phase II trial with four arms: control (usual diet), low-fat (LF) diet, flaxseed-supplemented (FS) diet, and FS+LS diet. The mean duration of dietary intervention was 30 to 31 days. Among the individual arms, the largest number of significant changes (baseline vs. preoperative follow-up) was observed in the LF arm, with 19 CAFs decreasing and one increasing (P < 0.05). Compared with the control arm, 6 CAFs-including proangiogenic factors (stromal-cell derived-1α) and myeloid factors (granulocyte-colony-stimulating factor, macrophage colony-stimulating factor)-all decreased in the LF arm compared with controls; three and four CAFs changed in the FS and FS+LF arms, respectively. Weight loss occurred in the LF arms and significantly correlated with VEGF decreases (P < 0.001). The CAFs that changed in the LF arm are all known to be regulated by NF-κB, and a pathway analysis identified NF-κB as the most likely regulatory network associated with these changes in the LF arm but not in the FS-containing arms. These results suggest that a LF diet without flaxseed may reduce levels of specific inflammatory CAFs and suggests that the NF-κB pathway may be a mediator of these changes.

Sarcomatoid mesothelioma: a clinical-pathologic correlation of 326 cases

Sarcomatoid mesothelioma is the least common, but most aggressive of the three major histological types of mesotheliomas. This study comprises 326 cases of sarcomatoid mesotheliomas among 2000 consecutive malignant mesothelioma cases received in consultation (16%). Patients included 312 men (96%) and 14 women (4%), with a median age of 70 years (range 41-94 years). Most tumors were pleural (319; 98%), and 7 were peritoneal (2%). Some desmoplastic features were identified in 110 cases (34%), and 70 (21%) were classified as desmoplastic. Rare subtypes included two cases with a lymphohistiocytoid pattern (<1%) and eight heterologous mesotheliomas (2%). Labeling for cytokeratins (CKs) was observed in 261/280 cases (93%), and for calretinin and vimentin in 31 and 91%, respectively. Pleural plaques were present in 79% of cases for which information was available, and asbestosis was diagnosed in 34/127 cases (27%). Median survival was 3.5 months. Fiber analysis was performed in 61 cases. The median asbestos body count was 1640/g wet lung tissue (by light microscopy). Amosite fibers were the most commonly identified fibers using energy-dispersive X-ray analysis and were significantly higher in the sarcomatoid cases, as were uncoated fibers using scanning electron microscopy. This study represents the largest series of sarcomatoid and desmoplastic malignant mesotheliomas to date and confirms the diagnostic usefulness of CK immunohistochemistry. The relationship with asbestos exposure--particularly amosite--and an association with pleural plaques and less often asbestosis is confirmed.

Association between statins and prostate tumor inflammatory infiltrate in men undergoing radical prostatectomy

BACKGROUND

Cholesterol-lowering drugs known as statins have been reported to have significant anti-inflammatory properties. Given that inflammation may contribute to prostate cancer progression and that statins may reduce the risk for advanced prostate cancer, we investigated whether statin use was associated with reduced intratumoral inflammation in radical prostatectomy (RP) specimens.

METHODS

Inflammation within index tumors of 236 men undergoing RP from 1996 to 2004 was graded by a single pathologist as grade 0 (absent), 1 (mild: < or =10%), and 2 (marked: >10%). Preoperative statin use was analyzed by grouping subjects as statin users or nonusers. Type and dosage of statin was accounted for using dose equivalents with 20 mg simvastatin as reference. Logistic regression was used to determine the association between statin use and intratumoral inflammation controlling for age, race, body mass index, prostate-specific antigen, year of surgery, clinical stage, pathologic Gleason sum, surgical margin status, extracapsular extension, seminal vesicle invasion, prostate weight, time from prostate biopsy to RP, and nonsteroidal anti-inflammatory drug use.

RESULTS

Preoperative statin use was significantly associated with lower risk for any (grade > or =1) intratumoral inflammation (odds ratio, 0.31; 95% confidence interval, 0.10-0.98; P = 0.047) on multivariable analysis, with doses > or =20 mg simvastatin equivalents being more strongly associated (relative to nonuse; odds ratio, 0.22; 95% confidence interval, 0.06-0.79; P = 0.02).

CONCLUSION

In a cohort of men undergoing RP, statin use was associated with significantly lower risk of any inflammation within prostate tumors.

IMPACT

Given previous reports that inflammation is associated with advanced prostate cancer, and statin use is associated with decreased prostate cancer progression risk, our findings suggest that inhibition of inflammation within tumors may be a potential mechanism for purported anti-prostate cancer properties of statins.

Dissecting the dynamics of serum prostate-specific antigen

I have examined more than 800 values of serum prostate-specific antigen (PSA) in 119 American Veterans during the time before their diagnosis of prostate cancer. These values appear to follow an exponential model with respect to time. Specifically, the model comprises a sum of 2 exponential functions: one for an early, slowly rising component of PSA and a second for a later, faster rising component. The parameters of each component comprise an amplitude and a relative velocity. Whereas the relative velocity of the slow component is significantly associated with the volume of benign tissue, both the amplitude and relative velocity of the fast component are significantly associated with the volume of tumor. The results suggest that at the time of diagnosis of prostate cancer the level and velocity of PSA reflect the combination of slow and fast components. Thus, this model provides insight into how benign and malignant tissues in the prostate determine the dynamics of PSA.

Accuracy of urine cytology and the significance of an atypical category

The "atypical urothelial cell" cytologic category is nonstandardized. We subclassify atypical cases to "atypical, favor a reactive process" or "atypical, unclear if reactive or neoplastic." We evaluated the predictive significance of atypical cases by looking at their histologic follow-up. Among the 1,114 patients and 3,261 specimens included, 282 specimens had histologic follow-up. An atypical diagnosis did not carry a significant increased risk of urothelial neoplasia compared with the benign category. Although an "atypical unclear" diagnosis carried a higher rate of detection of high-grade cancer on follow-up biopsy in comparison with "atypical reactive" or "negative" diagnoses (26/58 [45%] vs 15/52 [29%] and 16/103 [15.5%], respectively), this difference was not statistically significant. These results suggest that dividing atypical cases into 2 categories based on the level of cytologic suspicion of cancer does not add clinically relevant information within the atypical category. They also raise the question of the significance of the atypical category altogether.

Primary lung cancer vs metastatic breast cancer: a probabilistic approach

In this study, a mathematical and probabilistic model is used to study the probability that a lung tumor is a primary vs a metastasis from cancer of the breast. The model uses information from immunohistochemical stains for thyroid transcription factor (TTF)-1, mammaglobin, p63, and estrogen receptor and epidemiologic data about primary lung and metastatic breast cancers in women. The results demonstrate that these 4 stains can yield nearly certain diagnoses in approximately 80% of tumors falling into the pool of this differential diagnosis. Nevertheless, uncertainty of diagnosis remains for the 19% of tumors in the pool that are negative for TTF-1, mammaglobin, and p63.

Personalized prediction of tumor response and cancer progression on prostate needle biopsy

PURPOSE

To our knowledge in patients with prostate cancer there are no available tests except clinical variables to determine the likelihood of disease progression. We developed a patient specific, biology driven tool to predict outcome at diagnosis. We also investigated whether biopsy androgen receptor levels predict a durable response to therapy after secondary treatment.

MATERIALS AND METHODS

We evaluated paraffin embedded prostate needle biopsy tissue from 1,027 patients with cT1c-T3 prostate cancer treated with surgery and followed a median of 8 years. Machine learning was done to integrate clinical data with biopsy quantitative biometric features. Multivariate models were constructed to predict disease progression with the C index to estimate performance.

RESULTS

In a training set of 686 patients (total of 87 progression events) 3 clinical and 3 biopsy tissue characteristics were identified to predict clinical progression within 8 years after prostatectomy with 78% sensitivity, 69% specificity, a C index of 0.74 and a HR of 5.12. Validation in an independent cohort of 341 patients (total of 44 progression events) yielded 76% sensitivity, 64% specificity, a C index of 0.73 and a HR of 3.47. Increased androgen receptor in tumor cells in the biopsy highly significantly predicted resistance to therapy, ie androgen ablation with or without salvage radiotherapy, and clinical failure (p <0.0001).

CONCLUSIONS

Morphometry reliably classifies Gleason pattern 3 tumors. When combined with biomarker data, it adds to the hematoxylin and eosin analysis, and prostate specific antigen values currently used to assess outcome at diagnosis. Biopsy androgen receptor levels predict the likelihood of a response to therapy after recurrence and may guide future treatment decisions.

Differential diagnosis in immunohistochemistry with Bayes theorem

When immunohistochemical stains that are specific for specific tumor diagnoses do not yield diagnostic results, we often turn to less specific immunohistochemical stains and consider the resulting lists of possible tumor types. Typically, such lists are ordered according to tumor sensitivities for the stains. In probability terminology, sensitivity is the conditional probability of a positive stain given a specific tumor. Yet, the most useful probability to know is the probability of a specific tumor diagnosis, given a set of staining results. Bayes theorem provides this probability. To illustrate its use for differential diagnosis, I apply it here to the situation of carcinomas of uncertain primary site and use the information provided by stains for cytokeratin 7 and cytokeratin 20.

Fascin regulates prostate cancer cell invasion and is associated with metastasis and biochemical failure in prostate cancer

PURPOSE

Prostate cancer metastasis to secondary organs is considered an initial event in the development of hormone refractory disease and remains the major cause of death among prostate cancer patients. In this study, we investigated the role of fascin, a cytoskeleton actin-bundling protein involved in the formation of filopodia and cell migration, in prostate cancer progression.

EXPERIMENTAL DESIGN

Fascin protein expression was examined by immunohistochemistry in a cohort of 196 patients with localized prostate cancer and across several stages of disease progression, including hormone refractory disease. Cellular changes were also assessed in vitro and in vivo in DU145 prostate cancer cell line using fascin gene silencing.

RESULTS

Fascin epithelial expression was significantly up-regulated in localized and hormone refractory prostate cancer compared with benign prostate tissue (P<0.05). Furthermore, high fascin expression was associated with an increased rate of prostate-specific antigen recurrence following radical prostatectomy (P=0.075), signifying more aggressive clinical course, thus supporting a function for fascin in prostate cancer progression. In cellular models, fascin gene silencing using small interfering RNA in the androgen-independent prostate cancer cell line DU145 decreased cell motility and invasiveness while increasing cell adhesive properties. In addition, fascin small interfering RNA-expressing DU145 cells implanted orthotopically in mouse prostate showed significantly decreased growth (P<0.005) and drastically prevented the formation of lymph node metastases (P<0.001) compared with their matched controls.

CONCLUSIONS

Our data show a function of fascin in the regulation of prostate cancer progression and emphasize the importance of fascin as a prognostic marker for aggressive disease and as a potential therapeutic target for advanced androgen independent disease.

TMPRSS2-ERG fusion is frequently observed in Gleason pattern 3 prostate cancer in a Canadian cohort

PURPOSE

TMPRSS2-ERG gene fusion was recently reported as the most common gene rearrangement in prostate cancer (PCA).

RESULTS

In this cohort 41% of the patients showed positive gene fusion status in their PCA. The TMPRSS2-ERG gene fusion status was homogenous within the same cancer focus and 82% of fusion positive PCA were present in GS 6 or 7 vs. 14% in GS 8 (p = 0.004). Moreover, TMPRSS2-ERG fusion was present in 42% of Gleason pattern 3 vs. 27% of Gleason pattern 4 (p = 0.014). However, in this study, no significant association was noticed between TMPRSS2-ERG fusion status in relation to pathological stage, surgical margin or biochemical failure.

EXPERIMENTAL DESIGN

Using break-apart FISH assay to indirectly assess the fusion of TMPRSS2-ERG. We sought to characterize the incidence, pathological features and clinical parameters of TMPRSS2-ERG gene fusion in a cohort of 196 Canadian men treated by radical prostatectomy for localized PCA, and to investigate its potential as a biomarker in PCA.

CONCLUSION

The higher association of TMPRSS2-ERG with Gleason score 6 and 7 should be further investigated. If confirmed, this could have significant clinical impact in further stratifying patients with PCA should the TMPRSS2-ERG be confirmed as a prognostic biomarker.

Blast counts in bone marrow aspirate smears: analysis using the poisson probability function, bayes theorem, and information theory

Counts of cells or other phenomena observed through a microscope are numeric observations and, as such, are subject to mathematical and statistical analyses. For example, the Poisson probability function provides the probability of observing a particular number of blasts in a bone marrow aspirate, given an underlying true fraction of blasts present and a particular number of cells evaluated. Furthermore, using the Poisson function, Bayes theorem can provide the probabilities of specific categories of refractory anemia, given a number of observed blasts in a specific total of cells evaluated. Herein, I introduce and demonstrate these mathematical functions for the analysis of counts of blasts in marrow aspirates and explore the uncertainty that naturally arises when counts of blasts are near cut points used to separate the categories of refractory anemia without excess blasts, refractory anemia with excess blasts, and acute leukemia.

Flaxseed supplementation (not dietary fat restriction) reduces prostate cancer proliferation rates in men presurgery

BACKGROUND

Prostate cancer affects one of six men during their lifetime. Dietary factors are postulated to influence the development and progression of prostate cancer. Low-fat diets and flaxseed supplementation may offer potentially protective strategies.

METHODS

We undertook a multisite, randomized controlled trial to test the effects of low-fat and/or flaxseed-supplemented diets on the biology of the prostate and other biomarkers. Prostate cancer patients (n = 161) scheduled at least 21 days before prostatectomy were randomly assigned to one of the following arms: (a) control (usual diet), (b) flaxseed-supplemented diet (30 g/d), (c) low-fat diet (<20% total energy), or (d) flaxseed-supplemented, low-fat diet. Blood was drawn at baseline and before surgery and analyzed for prostate-specific antigen, sex hormone-binding globulin, testosterone, insulin-like growth factor-I and binding protein-3, C-reactive protein, and total and low-density lipoprotein cholesterol. Tumors were assessed for proliferation (Ki-67, the primary endpoint) and apoptosis.

RESULTS

Men were on protocol an average of 30 days. Proliferation rates were significantly lower (P < 0.002) among men assigned to the flaxseed arms. Median Ki-67-positive cells/total nuclei ratios (x100) were 1.66 (flaxseed-supplemented diet) and 1.50 (flaxseed-supplemented, low-fat diet) versus 3.23 (control) and 2.56 (low-fat diet). No differences were observed between arms with regard to side effects, apoptosis, and most serologic endpoints; however, men on low-fat diets experienced significant decreases in serum cholesterol (P = 0.048).

CONCLUSIONS

Findings suggest that flaxseed is safe and associated with biological alterations that may be protective for prostate cancer. Data also further support low-fat diets to manage serum cholesterol.

Percentage of tumor in prostatectomy specimens: a study of American Veterans

In this study, I have estimated the percentage of tumor by visual estimate in 447 prostatectomy specimens from American Veterans Affairs patients and related this measurement to overall survival. Although percentage of tumor was significantly related to the serum prostate-specific antigen level, tumor stage, and Gleason score-that is, it was not statistically independent from these-it was more closely associated with overall survival than any of them. Altogether, 2 variables available at the time of the prostatectomy related to survival: patient age (P = .0032; Cox proportional hazards model analysis) and percentage of tumor (P = .0013; Cox model). Patient age undoubtedly reflects the combination of comorbidities and general expected length of life. Percentage of tumor, by contrast, seems to efficiently reflect any undue hazard for early death due to prostate cancer. The results suggest that percentage of tumor is a useful prognostic variable for understanding risk of early death after prostatectomy.