Cancer overdiagnosis and overtreatment

Implementing active surveillance for low-risk thyroid carcinoma into clinical practice: collaborative recommendations for Latin America

The incidence of thyroid cancer is increasing globally, but mortality rates have remained steady. Many patients with thyroid cancer have low-risk, nonmetastatic intrathyroidal tumors smaller than 2 cm. Active surveillance has shown benefits in these patients, but the adoption of this approach remains below standard in Latin America. The purpose of this article is to identify ways to improve the incorporation of active surveillance into clinical practice for patients with low-risk thyroid carcinoma in Latin America, taking into consideration cultural and geographic factors. Current recommendations include three steps involving patient participation. The first step, which consists of the initial clinical examination, has eight factors requiring special attention. Anxiety must be managed while considering individual, disease-related, cognitive, and environmental aspects. Terms like "overdiagnosis", "incidentaloma," and "overtreatment" must be explained to the patient. Implementing precise terminology contributes to adequate disease perception, substantially reducing stress and anxiety. Clarifying the nonprogressive nature of thyroid cancer helps dispel myths surrounding the disease. The second step includes advice about procedures and guidelines for patients who choose active surveillance. Flexible monitoring techniques should be implemented, with regular check-ins scheduled based on patient needs. Reasons for adjusting treatment must be clearly communicated to the patient, and changes in preference regarding active surveillance should be considered in advance. The third step includes assistance during follow-up. Patients must be educated about ultrasound results and receive surgical indications from specialized physicians. The effectiveness of active surveillance can be reinforced by explaining to the patients the dynamics of changes in nodule size using clear and concise visual aids.

Overdiagnosis and overtreatment of ground-glass nodule-like lung cancer

Lung cancer has had one of the highest incidences and mortality in the world over the last few decades, which has aided in the promotion and popularization of screening for lung ground-glass nodules (GGNs). People have great psychological anxiety about GGN because of the chance that it will develop into lung cancer, which makes clinical treatment of GGN a generally excessive phenomenon. Overdiagnosis in screening has recently been mentioned in the literature. An important research emphasis of screening is how to reduce the incidence of overdiagnosis and overtreatment. This paper discusses from different aspects how to characterize the occurrence of overdiagnosis and overtreatment, how to reduce overdiagnosis and overtreatment, and future screening, follow-up, and treatment approaches.

Interaction between Genetic Risks and Socioeconomic Factors on Thyroid Cancer: Evidence from 0.5 Million UK Biobank Participants

BACKGROUND

There is a research gap between genetic predisposition, socioeconomic factors, and their interactions on thyroid tumorigenesis.

METHODS

Individual and genetic data were obtained from UK Biobank. Logistic regression models were used to evaluate the association between genetic risk, socioeconomic factors, and thyroid cancer (TCa). A stratified analysis was conducted to estimate their joint effects. A two-sample Mendelian randomization (MR) analysis was further used to examine the potential causality.

RESULTS

A total of 502,394 participants were included in this study. Three index loci (rs4449583, rs7726159, and rs7725218) of telomerase reverse transcriptase (TERT) were found to be significantly related to incident TCa. Association analyses showed that high genetic risk, low household income, and high education level were independent risk factors, while unemployment and frequent social connection were suggestive risk factors for TCa. Interaction analyses showed that in participants with low genetic risk, low household income was significantly associated with TCa (odds ratio [OR] = 1.56, 95% confidence interval [CI]: 1.00-2.46). In participants with high genetic risk, those with a high education level (OR = 1.32, 95%CI: 1.06-1.65) and frequent social connection (OR = 1.36, 95%CI: 1.02-1.81) had a significantly increased risk of TCa. However, no causal relationship was observed in the MR analysis.

CONCLUSION

Interactions exist between genetic risk, household income, education level, and social connection and thyroid cancer.

Cancer overdiagnosis: a challenge in the era of screening

"Screening" is a search for preclinical, asymptomatic disease, including cancer. Widespread cancer screening has led to large increases in early-stage cancers and pre-cancers. Ubiquitous public messages emphasize the potential benefits to screening for these lesions based on the underlying assumption that treating cancer at early stages before spread to other organs should make it easier to treat and cure, using more tolerable interventions. The intuition is so strong that public campaigns are sometimes launched without conducting definitive trials directly comparing screening to usual care. An effective cancer screening test should not only increase the incidence of early-stage preclinical disease but should also decrease the incidence of advanced and metastatic cancer, as well as a subsequent decrease in cancer-related mortality. Otherwise, screening efforts may be uncovering a reservoir of non-progressive and very slowly progressive lesions that were not destined to cause symptoms or suffering during the person's remaining natural lifespan: a phenomenon known as "overdiagnosis." We provide here a qualitative review of cancer overdiagnosis and discuss specific examples due to extensive population-based screening, including neuroblastoma, prostate cancer, thyroid cancer, lung cancer, melanoma, and breast cancer. The harms of unnecessary diagnosis and cancer therapy call for a balanced presentation to people considering undergoing screening, even with a test of accepted benefit, with a goal of informed decision-making. We also discuss proposed strategies to mitigate the adverse sequelae of overdiagnosis.

Nipping Diseases in the Bud? Ethical and Social Considerations of the Concept of 'Disease Interception'

‘Disease interception’ describes the treatment of a disease in its clinically inapparent phase and is increasingly used in medical literature. However, no precise definition, much less an ethical evaluation, has been developed yet. This article starts with a definition of ‘disease interception’ by distinguishing it from other preventions. It then analyses the ethical and social implications of the concept in light of the four principles of medical ethics by Beauchamp and Childress. The term ‘disease interception’ refers to a form of secondary prevention applied in a short interception window intended to prevent a preclinical disease from developing further. We propose the definition ‘early and targeted secondary prevention by treatment’. The ethical evaluation of the concept shows that while it promises to be beneficial, it raises a number of ethical and social challenges regarding patient autonomy and justice. In order to ensure decision-making that respects patient autonomy, commercially motivated metaphors such as ‘disease interception’ should make way for precise definitions. Future research should not only focus on how to detect clinically inapparent diseases but also on the ethical question, when this is justifiable and what consequences it has for the individual and society as a whole.

Induced Demand in Cancer Diagnosis

Context: Supplier-induced demand (SID) is an essential concept in health economics related to the diagnosis of different types of cancer and related expenditures. The current review considered studies on induced demand in cancer diagnosis. Evidence Acquisition: This systematic review investigated the induced diagnosis of cancer in four well-known databases (Scopus, Science Direct, Web of Science, and PubMed) from January 1980 to July 2019 using the keywords “induced demand,” “cancer,” and “diagnosis”. References of the studies found through the original search were also considered for analysis. Results: No studies focused on SID in cancer diagnosis could be found, thus indicating a significant deficiency in the discussion of SID in cancer diagnosis studies. Therefore, the terms most relevant to the concept of SID in cancer diagnosis were examined. Finally, 24 factors were categorized into three groups: economic, socio-cultural, and structural. The majority of evidence for the probability of SID in cancer diagnosis is related to overdiagnosis or early diagnosis caused by unnecessary screening (57.14% of reviewed articles) and the neglect of clinical practice guidelines (42.8% of reviewed articles), mainly by diagnostic imaging. Conclusions: Research focused explicitly on SID in cancer diagnosis is needed. Moreover, economic, social, and structural reforms related to the factors that connect overuse, overdiagnosis, and unnecessary services to cancer diagnosis are required to control costs and harm and provide the best benefits to patients.

Targeting the cancer lesion, not the whole prostate

Modern cancer treatment aims to conserve as much healthy tissue as possible. This has been challenging in the treatment of prostate cancer due to the difficulty in imaging the gland and concerns over leaving multifocal cancer untreated. With improvements in imaging and understanding of multifocal prostate cancer evidence now shows accurate treatment of just the primary focus of cancer or the index lesion can control progression or recurrence of the disease. Many different energy sources are now available to target the cancer lesion within the prostate with less significant side-effects on urinary and sexual function compared to radical treatment. Evidence shows that men value these functions highly and would even trade years of life in exchange for preserved retention of continence or erectile function. Focal treatment of prostate cancer aims to provide both cancer control and preservation of sexual and urinary functions so that men do not have to make a choice between the two. This is a treatment option that men clearly want and deserve.

Is possible to rule out clinically significant prostate cancer using PI-RADS v2 for the assessment of prostate MRI?

OBJECTIVES

To evaluate the diagnostic performance and interobserver agreement of PI-RADS v2.

MATERIALS AND METHODS

In this Institutional Review Board approved single-center retrospective study, 98 patients with clinically suspected PCa who underwent 3-T multiparametric MRI followed by MRI/TRUS fusion-guided prostate biopsy were included from June 2013 to February 2015. Two radiologists (R1 and R2) with 8 and 1 years of experience in abdominal radiology reviewed the MRI scans and assigned PI-RADS v2 scores in all prostate zones. PI-RADS v2 were compared to MRI/TRUS fusion-guided biopsy results, which were classified as negative, PCa, and significant PCa (sPCa).

RESULTS

Sensitivity, specificity, NPV, PPV and accuracy for PCa was 85.7% (same for all metrics) for R1 and 81.6%, 79.6%, 81.2%, 80.0% and 80.6% for R2. For detecting sPCa, the corresponding values were 95.3%, 85.4%, 95.9%, 83.7% and 89.8% for R1 and 93.0%, 81.8%, 93.7%, 86.7% and 86.7% for R2. There was substantial interobserver agreement in assigning PI-RADS v2 score as negative (1, 2, 3) or positive (4, 5) (Kappa=0.78). On multivariate analysis, PI-RADS v2 (p <0.001) was the only independent predictor of sPCa compared with age, abnormal DRE, prostate volume, PSA and PSA density.

CONCLUSIONS

Our study population demonstrated that PI-RADS v2 had high diagnostic accuracy, substantial interobserver agreement, and it was the only independent predictor of sPCa.

Clonal analysis of early-stage bilateral papillary thyroid cancer identifies field cancerization

INTRODUCTION

Bilaterality is a newly identified indicator for aggressive tumor behavior and poor outcome in papillary thyroid cancer. However, the clonal origin of these bilateral tumors remains unclear.

METHODS

Here we analyzed 28 pairs of early-stage papillary thyroid cancers (stage I-II without extra-thyroidal extension, lymph node metastasis or distant metastasis) that underwent surgery at First Affiliated Hospital of Zhejiang University School of Medicine (Hangzhou, China). Genomic DNA was extracted from paraffin-embedded tissues after microdissection and analyzed for BRAF mutation and X-chromosome inactivation.

RESULTS

A total of 16 patients (16/28, 57.1%) harbored different BRAF status in bilateral tumors. Fourteen patients were available for X-chromosome inactivation assay and 10 of them achieved informative results. Bilateral tumors from four cases had distinct patterns of X-chromosome inactivation. Combining the results of X-chromosome inactivation and BRAF analysis, we demonstrated that at least 64.3% (18/28) cases harbored discordant X-chromosome inactivation or BRAF status, indicating their independent clonal origin in bilateral tumors.

CONCLUSIONS

The present study confirms "field cancerization" in early-stage bilateral thyroid cancers, suggesting that these subtype papillary thyroid cancers should be treated as independent and localized tumors.

Live-cell phenotypic-biomarker microfluidic assay for the risk stratification of cancer patients via machine learning

The risk stratification of prostate cancer and breast cancer tumours from patients relies on histopathology, selective genomic testing, or on other methods employing fixed formalin tissue samples. However, static biomarker measurements from bulk fixed-tissue samples provide limited accuracy and actionability. Here, we report the development of a live-primary-cell phenotypic-biomarker assay with single-cell resolution, and its validation with prostate cancer and breast cancer tissue samples for the prediction of post-surgical adverse pathology. The assay includes a collagen-I/fibronectin extracellular-matrix formulation, dynamic live-cell biomarkers, a microfluidic device, machine-vision analysis and machine-learning algorithms, and generates predictive scores of adverse pathology at the time of surgery. Predictive scores for the risk stratification of 59 prostate cancer patients and 47 breast cancer patients, with values for area under the curve in receiver-operating-characteristic curves surpassing 80%, support the validation of the assay and its potential clinical applicability for the risk stratification of cancer patients.

Developing a Case-Based Blended Learning Ecosystem to Optimize Precision Medicine: Reducing Overdiagnosis and Overtreatment

INTRODUCTION

Precision medicine aims to focus on meeting patient requirements accurately, optimizing patient outcomes, and reducing under-/overdiagnosis and therapy. We aim to offer a fresh perspective on accuracy driven “age-old precision medicine” and illustrate how newer case-based blended learning ecosystems (CBBLE) can strengthen the bridge between age-old precision approaches with modern technology and omics-driven approaches.

METHODOLOGY

We present a series of cases and examine the role of precision medicine within a “case-based blended learning ecosystem” (CBBLE) as a practicable tool to reduce overdiagnosis and overtreatment. We illustrated the workflow of our CBBLE through case-based narratives from global students of CBBLE in high and low resource settings as is reflected in global health.

RESULTS

Four micro-narratives based on collective past experiences were generated to explain concepts of age-old patient-centered scientific accuracy and precision and four macro-narratives were collected from individual learners in our CBBLE. Insights gathered from a critical appraisal and thematic analysis of the narratives were discussed.

DISCUSSION AND CONCLUSION

Case-based narratives from the individual learners in our CBBLE amply illustrate their journeys beginning with “age-old precision thinking” in low-resource settings and progressing to “omics-driven” high-resource precision medicine setups to demonstrate how the approaches, used judiciously, might reduce the current pandemic of over-/underdiagnosis and over-/undertreatment.

Seeking certainty through narrative closure: men's stories of prostate cancer treatments in a state of liminality

Radical treatments of prostate cancer often lead to a pervasive liminal state that is characterised by multiple uncertainties that relate both to a possible recurrence of cancer and recovery from side effects, such as erectile and urinary dysfunctions. Liminality can make it difficult for cancer patients to narrate their experiences, as their stories lack a definite ending. After interviews with 22 Finnish men who had undergone radical prostatectomy, we analysed how men produce closure in their illness narratives. Focusing on the timelines of control visits or their anticipated recovery from side effects, these interviewees sought provisional certainty within a seemingly chaotic future. By locating erectile dysfunction in the wider context of a life-course and interpreting their fading sexuality as a 'natural' consequence of ageing, these men were adjusting to their post-operative lives. Our study further shows that the inability to adjust personal experiences to positive culturally available storylines that provide a chance for the narrative reconstruction of life, can cause materialised negative consequences, such as relationship breakdowns.

Active Surveillance for Papillary Thyroid Microcarcinoma: Challenges and Prospects

Active surveillance (AS) can be considered as an alternative to immediate surgery in low-risk papillary thyroid microcarcinoma (PTMC) without clinically apparent lymph nodes, gross extrathyroidal extension (ETE), and/or distant metastasis according to American Thyroid Association. However, in the past AS has been controversial, as evidence supporting AS in the management of PTMC was scarce. The most prominent of these controversies included, the limited accuracy and utility of ultrasound (US) in the detection of ETE, malignant lymph node involvement or the advent of novel lymph node malignancy during AS, and disease progression. We summarized publications and indicated: (1) US, performer-dependent, could not accurately diagnose gross ETE or malignant lymph node involvement in PTMC. However, the combination of computed tomography and US provided more accurate diagnostic performance, especially in terms of selection sensitivity. (2) Compared to immediate surgery patients, low-risk PTMC patients had a slightly higher rate of lymph node metastases (LNM), although the overall rate for both groups remained low. (3) Recent advances in the sensitivity and specificity of imaging and incorporation of diagnostic biomarkers have significantly improved confidence in the ability to differentiate indolent vs. aggressive PTMCs. Our paper reviewed current imagings and biomarkers with initial promise to help select AS candidates more safely and effectively. These challenges and prospects are important areas for future research to promote AS in PTMC.

Diagnosis and treatment for clinically localized prostate cancer. Adherence to the European Association of Urology clinical guidelines in a nationwide population-based study - GESCAP group

OBJECTIVE

To assess the adherence to European Association of Urology (EAU) guidelines in the management of prostate cancer (PCa) in Spain.

PATIENTS AND METHODS

Epidemiological, population-based, study including a national representative sample of 3,918 incident patients with histopathological confirmation during 2010; 95% of the patient's sample was followed up for at least one year. Diagnosis along with treatment related variables (for localized PCa -low, intermediate, high and locally-advanced by D'Amico risk stratification) was recorded. Differences between groups were tested with Chi-squared and Kruskal-Wallis tests.

RESULTS

Mean (SD) age of PCa patients was 68.48 (8.18). Regarding diagnostic by biopsy procedures, 64.56% of all patients had 8-12 cores in first biopsy and 46.5% of the patients over 75 years, with PSA<10ng/mL were biopsied. Staging by Computer Tomography (CT) or Bone Scan (BS) was used for determining tumor extension in 60.09% of high-risk cases and was applied differentially depending on patients' age; 3,293 (84.05%) patients received a treatment for localized PCa. Radical prostatectomy was done in 1,277 patients and 206 out of these patients also had a lymphadenectomy, being 4.64% low-risk, 22.81% intermediate-risk and 36.00% high-risk patients; 86.08% of 1,082 patients who had radiotherapy were treated with 3D or IMRT and 35.77% received a dose ≥75Gy; 419 patients were treated with brachytherapy (BT): 54.81% were low-risk patients, 22.84% intermediate-risk and 12.98% high-risk. Hormonotherapy (HT, n=521) was applied as single therapy in 9.46% of low-risk and 17.92% of intermediate-risk patients. Additionally, HT was combined with RT in 14.34% of lower-risk patients and 58.26% of high-risk patients, and 67.19% low-intermediate risk with RT and/or BT received neoadjuvant/concomitant/adjuvant HT. Finally, 83.75% of high-risk patients undergoing RT and/or BT also received HT.

CONCLUSIONS

Although EAU guidelines for PCa management are easily available in Europe, the adherence to their recommendations is low, finding the highest discrepancies in the need for a prostate biopsy and the diagnostic methods. Improve information and educational programs could allow a higher adherence to the guidelines and reduce the variability in daily practice. (Controlled-trials.com: ISRCTN19893319).

Active surveillance for low-risk localized prostate cancer: what do men and their partners think?

BACKGROUND

Active surveillance (AS) is recognized as a reasonable treatment option for low-risk localized prostate cancer (LPC) but continues to be chosen by a minority of men. To date, limited data are available regarding reasons why men with low-risk LPC adopt AS.

PURPOSE

The aim of this study is to better understand conceptualizations, experiences and reasons why men with low-risk LPC and their partners adopt AS.

METHODS

We conducted five focus groups (FGs), three among men with low-risk LPC who had chosen AS and two with their partners. FGs were video/audio recorded, transcribed and analysed using qualitative thematic analysis.

RESULTS

A total of 12 men and 6 partners (all women) participated in FG discussions. The most common reasons for choosing AS were seeing the LPC as 'small' or 'low grade' without need for immediate treatment and trusting their physician's AS recommendation. The most common concerns about AS were perceived unreliability of prostate specific antigen, pain associated with prostate biopsies and potential cancer progression. Partners saw themselves as very involved in their husbands' treatment decision-making process, more than men acknowledged them to be. Multiple terms including 'watchful waiting' were used interchangeably with AS. There appeared to be a lack of understanding that AS is not simply 'doing nothing' but is actually a recognized management option for low-risk LPC.

CONCLUSIONS

Emphasizing the low risk of a man's LPC and enhancing physician trust may increase acceptability of AS. Standardizing terminology and presenting AS as a reasonable and recognized management option may also help increase its adoption.

New Strategies in Prostate Cancer: Prostate-Specific Membrane Antigen (PSMA) Ligands for Diagnosis and Therapy

Key issues for prostate cancer patients are the detection of recurrent disease and the treatment of metastasized cancer. Early detection is a major challenge for all conventional imaging modalities. Furthermore, therapy of patients with hormone-resistant tumor lesions presents a major clinical challenge. Because the prostate-specific membrane antigen (PSMA) is frequently overexpressed in prostate cancer, several PSMA-targeting molecules are under development to detect and treat metastatic castration-resistant prostate cancer (mCRPC). mCRPC represents a situation where cure is no longer achievable and novel therapeutic approaches for palliation and increase of survival are needed. In this article, we discuss the recent development for noninvasive detection of recurrent disease and therapy of mCRPC with corresponding PSMA-targeted radioligands.

Overtreatment in cancer - is it a problem?

The word "cancer" invokes fear even today in those diagnosed with it, largely due to the deep-rooted stigma associated with this emotive word, one associated with an incurable and fatal disease. This was true in years gone by, when cancer patients presented late with symptoms from advanced disease. Today, however, in the era of screening and an awareness of the value of early detection, it is no longer the case. The last half century has heralded an unparalleled rise in every aspect of cancer research, diagnostics and therapeutics, with a better understanding of basic science, pathological classifications, risk factors, prognosis and treatments. Screening programs have been adopted or suggested for many cancers. The pendulum is shifting. A new concept has emerged - that of cancer overdiagnosis, and together with this, cancer overtreatment. Medicine still remains a science of uncertainty and an art of assessing probability. Until personalized medicine evolves to a level that a person's lifetime risk of clinically significant cancer formation and expected outcome can be computed with a great degree of precision and confidence, clinicians and patients have to be cognizant of the problem of cancer overdiagnosis and overtreatment. In this editorial, we explore the current evidence and magnitude of this problem.

Identifying in vivo DCE MRI markers associated with microvessel architecture and gleason grades of prostate cancer

BACKGROUND

To identify computer extracted in vivo dynamic contrast enhanced (DCE) MRI markers associated with quantitative histomorphometric (QH) characteristics of microvessels and Gleason scores (GS) in prostate cancer.

METHODS

This study considered retrospective data from 23 biopsy confirmed prostate cancer patients who underwent 3 Tesla multiparametric MRI before radical prostatectomy (RP). Representative slices from RP specimens were stained with vascular marker CD31. Tumor extent was mapped from RP sections onto DCE MRI using nonlinear registration methods. Seventy-seven microvessel QH features and 18 DCE MRI kinetic features were extracted and evaluated for their ability to distinguish low from intermediate and high GS. The effect of temporal sampling on kinetic features was assessed and correlations between those robust to temporal resolution and microvessel features discriminative of GS were examined.

RESULTS

A total of 12 microvessel architectural features were discriminative of low and intermediate/high grade tumors with area under the receiver operating characteristic curve (AUC) > 0.7. These features were most highly correlated with mean washout gradient (WG) (max rho = -0.62). Independent analysis revealed WG to be moderately robust to temporal resolution (intraclass correlation coefficient [ICC] = 0.63) and WG variance, which was poorly correlated with microvessel features, to be predictive of low grade tumors (AUC = 0.77). Enhancement ratio was the most robust (ICC = 0.96) and discriminative (AUC = 0.78) kinetic feature but was moderately correlated with microvessel features (max rho = -0.52).

CONCLUSION

Computer extracted features of prostate DCE MRI appear to be correlated with microvessel architecture and may be discriminative of low versus intermediate and high GS.

Androgen receptor and chemokine receptors 4 and 7 form a signaling axis to regulate CXCL12-dependent cellular motility

Background

Identifying cellular signaling pathways that become corrupted in the presence of androgens that increase the metastatic potential of organ-confined tumor cells is critical to devising strategies capable of attenuating the metastatic progression of hormone-naïve, organ-confined tumors. In localized prostate cancers, gene fusions that place ETS-family transcription factors under the control of androgens drive gene expression programs that increase the invasiveness of organ-confined tumor cells. C-X-C chemokine receptor type 4 (CXCR4) is a downstream target of ERG, whose upregulation in prostate-tumor cells contributes to their migration from the prostate gland. Recent evidence suggests that CXCR4-mediated proliferation and metastasis of tumor cells is regulated by CXCR7 through its scavenging of chemokine CXCL12. However, the role of androgens in regulating CXCR4-mediated motility with respect to CXCR7 function in prostate-cancer cells remains unclear.

Methods

Immunocytochemistry, western blot, and affinity-purification analyses were used to study how androgens influenced the expression, subcellular localization, and function of CXCR7, CXCR4, and androgen receptor (AR) in LNCaP prostate-tumor cells. Moreover, luciferase assays and quantitative polymerase chain reaction (qPCR) were used to study how chemokines CXCL11 and CXCL12 regulate androgen-regulated genes (ARGs) in LNCaP prostate-tumor cells. Lastly, cell motility assays were carried out to determine how androgens influenced CXCR4-dependent motility through CXCL12.

Results

Here we show that, in the LNCaP prostate-tumor cell line, androgens coordinate the expression of CXCR4 and CXCR7, thereby promoting CXCL12/CXCR4-mediated cell motility. RNA interference experiments revealed functional interactions between AR and CXCR7 in these cells. Co-localization and affinity-purification experiments support a physical interaction between AR and CXCR7 in LNCaP cells. Unexpectedly, CXCR7 resided in the nuclear compartment and modulated AR-mediated transcription. Moreover, androgen-mediated cell motility correlated positively with the co-localization of CXCR4 and CXCR7 receptors, suggesting that cell migration may be linked to functional CXCR4/CXCR7 heterodimers. Lastly, CXCL12-mediated cell motility was CXCR7-dependent, with CXCR7 expression required for optimal expression of CXCR4 protein.

Conclusions

Overall, our results suggest that inhibition of CXCR7 function might decrease the metastatic potential of organ-confined prostate cancers.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1201-5) contains supplementary material, which is available to authorized users.

Contemporary use of initial active surveillance among men in Michigan with low-risk prostate cancer

BACKGROUND

Active surveillance (AS) has been proposed as an effective strategy to reduce overtreatment among men with lower risk prostate cancers. However, historical rates of initial surveillance are low (4-20%), and little is known about its application among community-based urology practices.

OBJECTIVE

To describe contemporary utilization of AS among a population-based sample of men with low-risk prostate cancer.

DESIGN, SETTING, AND PARTICIPANTS

We performed a prospective cohort study of men with low-risk prostate cancer managed by urologists participating in the Michigan Urological Surgery Improvement Collaborative (MUSIC).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The principal outcome was receipt of AS as initial management for low-risk prostate cancer including the frequency of follow-up prostate-specific antigen (PSA) testing, prostate biopsy, and local therapy. We examined variation in the use of surveillance according to patient characteristics and across MUSIC practices. Finally, we used claims data to validate treatment classification in the MUSIC registry.

RESULTS AND LIMITATIONS

We identified 682 low-risk patients from 17 MUSIC practices. Overall, 49% of men underwent initial AS. Use of initial surveillance varied widely across practices (27-80%; p=0.005), even after accounting for differences in patient characteristics. Among men undergoing initial surveillance with at least 12 mo of follow-up, PSA testing was common (85%), whereas repeat biopsy was performed in only one-third of patients. There was excellent agreement between treatment assignments in the MUSIC registry and claims data (κ=0.93). Limitations include unknown treatment for 8% of men with low-risk cancer.

CONCLUSIONS

Half of men in Michigan with low-risk prostate cancer receive initial AS. Because this proportion is much higher than reported previously, our findings suggest growing acceptance of this strategy for reducing overtreatment.

PATIENT SUMMARY

We examined the use of initial active surveillance for the management of men with low-risk prostate cancer across the state of Michigan. We found that initial surveillance is used much more commonly than previously reported, but the likelihood of a patient being placed on surveillance depends strongly on where he is treated.

Is lower socioeconomic status associated with more advanced thyroid cancer stage at presentation? A study in two Canadian centers

BACKGROUND

Some studies have shown a higher incidence of thyroid cancer in patients with insurance coverage and higher socioeconomic status (SES), and a higher thyroid cancer stage in patients with lower SES, suggesting SES-related health disparity in thyroid cancer. However, it is not known if the same is evident under a universal healthcare system such as that in Canada.

METHODS

We used data from the Canadian Thyroid Cancer Consortium, a large thyroid cancer registry that collects data from two major thyroid cancer referral centers (London, Ontario, and Halifax, Nova Scotia). We included patients who presented with thyroid cancer between 1998 and 2011. We determined age at presentation, sex, and thyroid cancer status using the American Joint Committee on Cancer (AJCC) staging criteria. Individuals' postal codes were used to retrieve data from the Canadian census for the years 1996, 2001, and 2006 to approximate household income. Ordered logistic regression was used to determine odds ratios of presenting with more advanced stage thyroid cancer as they relate to income, age, and sex.

RESULTS

We included 1701 patients: 1334 cases from London and 367 from Halifax. Thyroid cancer was diagnosed more frequently in the higher SES groups (p<0.001). Compared to patients in the top income quintile, patients in the lowest and second-lowest income quintiles had significantly higher odds of having more advanced stage thyroid cancer at presentation (OR 1.58, p=0.002; 1.37, p=0.024 respectively).

CONCLUSIONS

Our study suggests that, similar to countries that lack a universal healthcare system, health disparity in thyroid cancer also exists in Canada. It appears that while thyroid cancers were diagnosed more frequently in Canadian patients of higher SES, Canadian patients in the lower SES groups had more advanced stage thyroid cancer at presentation.

The biology and natural history of prostate cancer: a short introduction

This chapter aims to serve as a quick glance outlining an overall picture of mainstream thoughts, and to serve as a point of departure for more thorough discussions. The introduction of PSA testing has immensely complicated research in prostate cancer epidemiology and biology and added new clinical and biological domains. As for many cancers, age and ethnic origin are the strongest known risk factors. While migrant studies imply that environment and/or personal life style is important, epidemiological studies have failed to establish any strong leads. Despite the known androgen dependence of prostate cancer, there is little to support that circulating levels of androgens, estrogens or 5-alpha-reductase are associated with risk of developing the disease. However, a consistent finding is a positive association with levels of Insulin-like Growth Factor-1 (IGF-1). Prostate cancer is one of the cancers most strongly related to inherited susceptibility, even when taking into account that family history of prostate cancer triggers PSA testing among relatives. A number of somatic genetic alterations (amplifications, deletions, point mutations, translocations) are associated with prostate cancer risk. Findings for alterations in FASN, HPN, AMACR and MYC have been fairly consistent. Recent research shows that the notion of "hormone-independent prostate cancer" has to be revised: most prostate cancers remain dependent on androgen receptor signalling also after progression despite traditional androgen deprivation therapy. Traditional markers of stage and type of disease still play a major role for prognostication and treatment decisions. Prostate cancer is one of the few cancers where patients have been recommended watchful waiting or active surveillance. This provides opportunities for studies of natural history of the disease. The understanding of prostate cancer aetiology and natural history has progressed slowly. However, the current situation is positively challenging and opens up possibilities for fruitful research.

Prostate cancer and the increasing role of active surveillance

Prostate cancer (PC) is the most often diagnosed non-skin cancer and the second leading cause of cancer-related death among men in the United States. As a result, for many years the American Urological Association (AUA) and the American Cancer Society have issued statements recommending screening for PC, resulting in its widespread implementation in the United States. Recently, the United States Preventative Services Task Force gave PC screening a recommendation of D, that is, against PC screening for all men. The AUA countered this recommendation, stating that since the development of PC screening using prostate-specific antigen, a reduction in PC-specific mortality has been seen, and that the risk reduction occurred in a setting in which many of the patients were not aggressively treated for prostate cancer. Active surveillance may be described as a method to potentially delay or obviate the need for treatment in men with clinically insignificant PC or PC thought to be at low risk for progression. Studies have shown no significant difference in outcome or pathology between men with low risk PC who receive treatment at the point of progression and those undergoing immediate treatment. Ongoing studies are evaluating the efficacy and utility of active surveillance for low-risk PC. Interim results of these studies have shown that approximately 30% of patients progress on active surveillance. However, "progression" does not necessarily mean treatment failure; rarely do patients develop locally advanced or metastatic disease. Active surveillance has also been shown to be cost-effective when compared with immediate treatment for PC. Longer follow-up may continue to show an increased benefit of active surveillance as a reasonable initial approach to the management of men with low-risk, clinically localized PC.

The PICTURE study -- prostate imaging (multi-parametric MRI and Prostate HistoScanning™) compared to transperineal ultrasound guided biopsy for significant prostate cancer risk evaluation

OBJECTIVE

The primary objective of the PICTURE study is to assess the negative predictive value of multi-parametric MRI (mp-MRI) and Prostate HistoScanning™ (PHS) in ruling-out clinically significant prostate cancer.

PATIENTS AND METHODS

PICTURE is a prospective diagnostic validating cohort study conforming to level 1 evidence. PICTURE will assess the diagnostic performance of multi-parametric Magnetic Resonance Imaging (mp-MRI) and Prostate HistoScanning™ (PHS) ultrasound. PICTURE will involve validating both index tests against a reference test, transperineal Template Prostate Mapping (TPM) biopsies, which can be applied in all men under evaluation. Men will be blinded to the index test results and both index tests will be reported prospectively prior to the biopsies being taken to ensure reporter blinding. Paired analysis of each of the index tests to the reference test will be done at patient level. Those men with an imaging lesion will undergo targeted biopsies to assess the clinical utility of sampling only suspicious areas. The study is powered to assess the negative predictive value of these imaging modalities in ruling-out clinically significant prostate cancer.

DISCUSSION

The PICTURE study aims to assess the performance characteristics of two imaging modalities (mp-MRI and Prostate HistoScanning) for their utility in the prostate cancer pathway. PICTURE aims to identify if either imaging test may be useful for ruling out clinically significant disease in men under investigation, and also to examine if either imaging modality is useful for the detection of disease. Recruitment is underway and expected to complete in 2014.

Mast cells as a potential prognostic marker in prostate cancer

Despite years of intensive investigation that has been made in understanding prostate cancer, it remains one of the major men's health issues and the leading cause of death worldwide. It is now ascertained that prostate cancer emerges from multiple spontaneous and/or inherited alterations that induce changes in expression patterns of genes and proteins that function in complex networks controlling critical cellular events. It is now accepted that several innate and adaptive immune cells, including T- and B-lymphocytes, macrophages, natural killer cells, dendritic cells, neutrophils, eosinophils, and mast cells (MCs), infiltrate the prostate cancer. All of these cells are irregularly scattered within the tumor and loaded with an assorted array of cytokines, chemokines, and inflammatory and cytotoxic mediators. This complex framework reflects the diversity in tumor biology and tumor-host interactions. MCs are well-established effector cells in Immunoglobulin-E (Ig-E) associated immune responses and potent effector cells of the innate immune system; however, their clinical significance in prostate cancer is still debated. Here, these controversies are summarized, focusing on the implications of these findings in understanding the roles of MCs in primary prostate cancer.

Malignancy risk assessment in patients with thyroid nodules using classification and regression trees

Purpose. We sought to investigate the utility of classification and regression trees (CART) classifier to differentiate benign from malignant nodules in patients referred for thyroid surgery. Methods. Clinical and demographic data of 271 patients referred to the Sadoughi Hospital during 2006–2011 were collected. In a two-step approach, a CART classifier was employed to differentiate patients with a high versus low risk of thyroid malignancy. The first step served as the screening procedure and was tailored to produce as few false negatives as possible. The second step identified those with the lowest risk of malignancy, chosen from a high risk population. Sensitivity, specificity, positive and negative predictive values (PPV and NPV) of the optimal tree were calculated. Results. In the first step, age, sex, and nodule size contributed to the optimal tree. Ultrasonographic features were employed in the second step with hypoechogenicity and/or microcalcifications yielding the highest discriminatory ability. The combined tree produced a sensitivity and specificity of 80.0% (95% CI: 29.9–98.9) and 94.1% (95% CI: 78.9–99.0), respectively. NPV and PPV were 66.7% (41.1–85.6) and 97.0% (82.5–99.8), respectively. Conclusion. CART classifier reliably identifies patients with a low risk of malignancy who can avoid unnecessary surgery.

Active surveillance for prostate cancer: overview and update

Low-risk prostate cancer: How I would treat it? Overtreatment of many conditions diagnosed by screening has become increasingly recognized as a contemporary malady associated with modern medicine's efforts at earlier detection. The diagnosis of low-grade prostate cancer clearly qualifies as an example of potential overdiagnosis and overtreatment. Active surveillance for low-risk prostate cancer is an attempt to reduce the overtreatment of the disease. The approach involves initial expectant management rather than immediate therapy. Curative treatment is deferred while the patient is monitored and offered for evidence of risk reclassification to a more aggressive form of the disease. The basis for this approach is substantial evidence confirming the long natural history of most prostate cancers. The objective is to balance the risks of overtreatment and associated adverse quality of life effects, against the risk of progression of disease and a missed opportunity for curative therapy. Low-risk prostate cancer is more accurately viewed as one of several risk factors for the patient harboring higher-grade disease, rather than a life-threatening condition. This approach is similar to that taken historically for so-called precancerous conditions, such as PIN or ASAP, where patients were managed with close follow-up but without radical intervention unless clear evidence of more aggressive disease is identified. Active surveillance is increasingly viewed as the management of choice for patients with very low-risk (low-grade, low-volume prostate cancer) and low-risk (low-grade but higher volume) disease.

Epidemiology of prostate cancer in the Asia-Pacific region

The purpose of this paper was to examine and compare available data on incidence, mortality and survival for countries in the Asia-Pacific region. Incidence data were obtained from GLOBOCAN 2008, other online data sources and individual cancer registries. Country-specific mortality statistics by individual year were sourced from the World Health Organization Statistical Information System Mortality Database. All incidence and mortality rates were directly age-standardised to the Segi World Standard population and joinpoint models were used to assess trends. Data on survival were obtained from country-specific published reports where available. Approximately 14% (122,000) of all prostate cancers diagnosed worldwide in 2008 were within the Asia-Pacific region (10 per 100,000 population), with three out of every four of these prostate cancer cases diagnosed in either Japan (32%), China (28%) or Australia (15%). There were also about 42,000 deaths due to prostate cancer in the Asia-Pacific region (3 per 100,000). For the nine countries with incidence trend data available, eight showed recent significant increases in prostate cancer incidence. In contrast, recent decreases in prostate cancer mortality have been reported for Australia, Japan and New Zealand, but mortality has increased in several other countries. The lack of population-based data across most of the countries in this region limits the ability of researchers to understand and report on the patterns and distribution of this important cancer. Governments and health planners typically require quantitative evidence as a motivation for change. Unless there is a widespread commitment to improve the collection and reporting of data on prostate cancer it is likely that the burden of prostate cancer will continue to increase. Enhancing knowledge transfer between countries where there are differentials in capacity, policy and experience may provide the necessary impetus and opportunity to overcome at least some of the existing barriers.

Estimates of cancer burden in Umbria

Aims and background

Model-based estimates and projections of epidemiological indicators related to cancer are important tools to support public health policies and planning. The aim of the present study is to produce projections of cancer incidence, mortality and prevalence for the Umbria region (900,000 inhabitants) in central Italy.

Methods

The estimations were obtained by applying the MIAMOD method, a statistical back-calculation approach to derive incidence and prevalence figures starting from mortality and relative survival data. Published data from the Italian cancer registries were modeled in order to estimate regional cancer survival. Estimated incidence rates were validated with observed incidence rates obtained from the Umbria regional cancer registry.

Results

The most frequent cancer sites estimated were colon-rectum, prostate and breast in women, with 970, 615 and 729 new diagnoses, respectively, in 2012. The incidence rates were increasing for female lung cancer, male colorectal cancer, and melanoma. By contrast, the rates have been declining for cervix and stomach cancer. For lung cancer and prostate cancer in men and colorectal cancer in women the rates increased, reaching a peak in different periods, and then decreased. The incidence rates of breast cancer rose, reaching a plateau in the mid 2010s. Favorable mortality trends were predicted for all cancers except skin melanoma and lung cancer in women. The prevalence of cancer was increasing with the only exception of cervical cancer in women and lung cancer in men in the most recent estimation period.

Conclusion

The scenario found for cancer incidence and prevalence was largely influenced by screening activities, so that increasing or stable incidence rates may reflect active preventive efforts. Aging, screening, and more complex and costly treatments pose a problem of sustainability and selection of interventions to the regional oncology system. Evaluation of effectiveness of intervention and cost-benefit analyses will be important to ensure cancer control in the future.

Development and clinical validation of a real-time PCR assay for PITX2 DNA methylation to predict prostate-specific antigen recurrence in prostate cancer patients following radical prostatectomy

Prostate cancer is the most common cancer among men. The prospective discrimination of aggressive and clinically insignificant tumors still poses a significant and, as yet, unsolved problem. PITX2 DNA methylation is a strong prognostic biomarker in prostate cancer. Recently, a diagnostic microarray for prostate cancer prognosis based on PITX2 methylation has been developed and validated. Because this microarray requires nonstandard laboratory equipment, its use in a diagnostic setting is limited. This study aimed to develop and validate an alternative quantitative real-time PCR assay for measuring PITX2 methylation that can easily be established in clinical laboratories, thereby facilitating the implementation of this biomarker in clinical practice. A methylation cut-off for patient stratification was established in a training cohort (n = 157) and validated in an independent test set (n = 523) of men treated with radical prostatectomy. In univariate Cox proportional hazards analysis, PITX2 hypermethylation was a significant predictor for biochemical recurrence (P < 0.001, hazard ratio = 2.614). Moreover, PITX2 hypermethylation added significant prognostic information (P = 0.003, hazard ratio = 1.814) to the Gleason score, pathological T stage, prostate-specific antigen, and surgical margins in a multivariate analysis. The clinical performance was particularly high in patients at intermediate risk (Gleason score of 7) and in samples containing high tumor cell content. This assay might aid in risk stratification and support the decision-making process when determining whether a patient might benefit from adjuvant treatment after radical prostatectomy.

Preventive evolutionary medicine of cancers

Evolutionary theory predicts that once an individual reaches an age of sufficiently low Darwinian fitness, (s)he will have reduced chances of keeping cancerous lesions in check. While we clearly need to better understand the emergence of precursor states and early malignancies as well as their mitigation by the microenvironment and tissue architecture, we argue that lifestyle changes and preventive therapies based in an evolutionary framework, applied to identified high-risk populations before incipient neoplasms become clinically detectable and chemoresistant lineages emerge, are currently the most reliable way to control or eliminate early tumours. Specifically, the relatively low levels of (epi)genetic heterogeneity characteristic of many if not most incipient lesions will mean a relatively limited set of possible adaptive traits and associated costs compared to more advanced cancers, and thus a more complete and predictable understanding of treatment options and outcomes. We propose a conceptual model for preventive treatments and discuss the many associated challenges.

Active surveillance for low-risk prostate cancer

Active surveillance (AS) is an important management strategy for men diagnosed with low-risk prostate cancer (PCa). The need for AS is increasing due to the awareness that many PCa are identified that show a low growth potential and therefore are likely to remain clinically asymptomatic during the lifetime of an individual. Currently there is no good method to prevent the overdiagnosis of indolent cancers upfront. During the last decade, several studies on AS around the world have made observations that feed the discussion on how to select and monitor these patients, how to proceed with the research to develop a better and more precise clinical definition of indolent cancers and how to manage men under AS clinically. Furthermore, patients' perspectives have become clearer, and quality of life studies give direction to the practical approach and care for patients and partners. This paper reflects the consensus on the state of the art and the future direction of AS, based on the Inside Track Conference "Active Surveillance for low risk prostate cancer" (Chairmen: C.H. Bangma, NL, and L. Klotz, CA; Co-Chairmen: L.J. Denis, BE, and C. Parker, UK; Scientific Coordinators: M. J. Roobol, NL, and E.W. Steyerberg, NL), organized by the European School of Oncology in collaboration with Europa Uomo in Rotterdam, the Netherlands in January 2012. Topics for discussion were the optimisation of patient selection based on indolent disease definition, the incorporation of therapeutic agents into AS programs, the optimisation of patient care, and the application of emerging technologies and biomarkers.