Prognostic Value of Plasma hPG80 (Circulating Progastrin) in Metastatic Renal Cell Carcinoma

The Breast to Bone (B2B) Cohort Study to Prevent, Detect and Improve Treatment of Metastatic Disease: Baseline Assessment, Description and Progress

Women diagnosed with early-stage breast cancer can develop metastatic disease following successful initial treatment, with bone being the most common site of metastases. The Breast to Bone (B2B) cohort study of early-stage breast cancer patients was established as a research platform to study the basic biology of breast cancer to bone metastasis and to identify the factors that could improve prevention, early detection and treatment for this debilitating and incurable disease. The B2B cohort includes 478 women diagnosed with incident primary breast cancer (stages I to III) who were recruited from Calgary, Alberta and surrounding areas between February 2010 and July 2015. Four projects have been conducted to date, utilizing data and samples from this cohort. These studies have found the following: (a) women with insufficient or deficient levels of vitamin D (25[OH]D) concentrations in pretreatment serum samples had larger tumors and higher breast cancer grades, (b) several metabolomic biomarkers and cytokines were associated with tumor characteristics and time to recurrence, (c) additional biomarkers were found to be predictive for the high risk of bone metastasis and (d) circulating progastrin (hPG80) was associated with multiple survival outcomes. These research studies and future ones will provide new evidence on bone metastasis etiology in women diagnosed with early-stage breast cancer, improve identification of those at high risk and contribute to personalized treatment and prevention options.

Liquid biopsy for renal cell carcinoma

Liquid biopsies offer a less invasive alternative to tissue biopsies for diagnosis, prognosis, and determining therapeutic potential in renal cell carcinoma (RCC). Unfortunately, clinical studies using liquid biopsy biomarkers in RCC are limited. Accordingly, we examine RCC biomarkers, derived from urine, plasma, serum and feces of potential impact and clinical outcome in these patients. A PRISMA checklist was used to identify valuable liquid biopsy biomarkers for diagnosis (plasma cfDNA, serum- or urine-derived circulating RNAs, exosomes and proteins), prognosis (plasma cfDNA, plasma- or serum-derived RNAs, and proteins), and therapeutic response (plasma- and serum-derived proteins). Although other analytes have been identified, their application for routine clinical use remains unclear. In general, panels appear more effective than single biomarkers. Important considerations included proof of reproducibility. Unfortunately, many of the examined studies were insufficiently large and lacked multi-center rigor. Cost-effectiveness was also not available. Accordingly, it is clear that more standardized protocols need to be developed before liquid biopsies can be successfully integrated into clinical practice in RCC.

Progastrin: An Overview of Its Crucial Role in the Tumorigenesis of Gastrointestinal Cancers

Defining predictive biomarkers for targeted therapies and optimizing anti-tumor immune response is a main challenge in ongoing investigations. Progastrin has been studied as a potential biomarker for detecting and diagnosing various malignancies, and its secretion has been associated with cell proliferation in the gastrointestinal tract that may promote tumorigenesis. Progastrin is a precursor molecule of gastrin, synthesized as pre-progastrin, converted to progastrin after cleavage, and transformed into amidated gastrin via biosynthetic intermediates. In cancer, progastrin does not maturate in gastrin and becomes a circulating and detectable protein (hPG80). The development of cancer is thought to be dependent on the progressive dysregulation of normal signaling pathways involved in cell proliferation, thus conferring a growth advantage to the cells. Understanding the interaction between progastrin and the immune system is essential for developing future cancer strategies. To that end, the present review will approach the interlink between gastrointestinal cancers and progastrin by exploring the underlying molecular steps involved in the initiation, evolution, and progression of gastrointestinal cancers. Finally, this review will focus on the clinical applications of progastrin and investigate its possible use as a diagnostic and prognostic tumor circulating biomarker for disease progression and treatment effectiveness, as well as its potential role as an innovative cancer target.

Association between post-operative hPG80 (circulating progastrin) detectable level and worse prognosis in glioblastoma

BACKGROUND

Patients with glioblastomas have a dismal prognosis, and there is no circulating predictive or prognostic biomarker. Circulating progastrin, hPG80, is a tumor-promoting peptide present in the blood of patients with various cancers that has been shown to have prognostic value. We evaluated the prognostic value of plasma hPG80 in patients with isocitrate dehydrogenase-wild type glioblastoma after surgery.

PATIENTS AND METHODS

A multicentric retrospective study in glioblastoma patients treated with standard radio-chemotherapy was conducted. The hPG80 levels were measured in plasma EDTA samples collected after surgery with an ELISA DxPG80.lab kit (Biodena Care, Montpellier, France), which has a detection threshold of 1.2 pM. The relationship between post-operative hPG80 plasma levels, in combination with other known prognostic factors, and patients' progression-free survival (PFS) and overall survival (OS) was evaluated.

RESULTS

Sixty-nine patients were assessable. Plasma samples were collected after tumor biopsy (B), partial resection (PR), and complete resection (CR) for 22, 25, and 22 patients, respectively. At a median concentration of 5.37 pM (interquartile range 0.00-13.90 pM), hPG80 was detected in 48 (70%) patients (hPG80+). CR was associated with significant lower values of hPG80 levels: the median value was 0.7 versus 9.1 pM for PR (P = 0.02) and 8.3 pM for B (P = 0.004). The hPG80 detection rate was also significantly lower: 50% (CR) versus 72% (PR) versus 86% (B) (P = 0.005). The median follow-up was 39 months [22.4 months-not reached]. hPG80 post-operative detection was associated with numerically shorter PFS (6.4 versus 9.4 months, P = 0.13) and OS (14.5 versus 20.9 months, P = 0.11). In multivariate analysis, hPG80 was a prognostic factor for OS (P = 0.034).

CONCLUSIONS

Circulating hPG80 could serve as a new prognostic biomarker after surgery in patients with glioblastoma treated with radio-chemotherapy.

Chasing the Role of miRNAs in RCC: From Free-Circulating to Extracellular-Vesicle-Derived Biomarkers

Renal cell carcinoma (RCC) is the second most common cancer of the urinary system. The current therapeutic strategies are based on partial or total nephrectomy and/or targeted therapies based on immune checkpoint inhibitors to which patients are often refractory. Preventive and screening strategies do not exist and the few available biomarkers for RCC are characterized by a lack of sensitivity, outlining the need for novel noninvasive and sensitive biomarkers for early diagnosis and better disease monitoring. Blood liquid biopsy (LB) is a non- or minimally invasive procedure for a more representative view of tumor heterogeneity than a tissue biopsy, potentially allowing the real-time monitoring of cancer evolution. Growing interest is focused on the extracellular vesicles (EVs) secreted by either healthy or tumoral cells and recovered in a variety of biological matrices, blood included. EVs are involved in cell-to-cell crosstalk transferring their mRNAs, microRNAs (miRNAs), and protein content. In particular, transferred miRNAs may regulate tumorigenesis and proliferation also impacting resistance to apoptosis, thus representing potential useful biomarkers. Here, we present the latest efforts in the identification of circulating miRNAs in blood samples, focusing on the potential use of EV-derived miRNAs as RCC diagnostic and prognostic markers.

Plasma hPG80 (Circulating Progastrin) as a Novel Prognostic Biomarker for early-stage breast cancer in a breast cancer cohort

BACKGROUND

Recurrence and metastases are still frequent outcomes after initial tumour control in women diagnosed with breast cancer. Although therapies are selected based on tumour characteristics measured at baseline, prognostic biomarkers can identify those at risk of poor outcomes. Circulating progastrin or hPG₈₀ was found to be associated with survival outcomes in renal and hepatocellular carcinomas and was a plausible prognostic biomarker for breast cancer.

METHODS

Women with incident breast cancers from Calgary, Alberta, Canada enrolled in the Breast to Bone (B2B) study between 2010 to 2016 and provided blood samples prior to any treatment initiation. Plasma from these baseline samples were analysed for circulating progastrin or hPG₈₀. Participant characteristics as well as tumour ones were evaluated for their association with hPG₈₀ and survival outcomes (time to recurrence, recurrence - free survival, breast cancer specific survival and overall survival) in Cox proportional hazards regression models.

RESULTS

The 464 participants with measurable hPG₈₀ in this study had an average age of 57.03 years (standard deviation of 11.17 years) and were predominantly diagnosed with Stage I (52.2%) and Stage II (40.1%) disease. A total of 50 recurrences and 50 deaths were recorded as of June 2022. In Cox PH regression models adjusted for chemotherapy, radiation therapy, cancer stage and age at diagnosis, log hPG₈₀ (pmol/L) significantly increased the risks for recurrence (Hazard Ratio (HR) = 1.330, 95% Confidence Interval (CI) = (0.995 - 1.777, p = 0.054)), recurrence-free survival (HR = 1.399, 95% CI = (1.106 - 1.770), p = 0.005) and overall survival (HR = 1.385, 95% CI = (1.046 - 1.834), = 0.023) but not for breast cancer specific survival (HR = 1.015, 95% CI = (0.684 - 1.505), p = 0.942).

CONCLUSIONS

hPG₈₀ levels measured at diagnosis were significantly associated with the risk of recurrence or death from any cause in women with breast cancer. Since the recurrence rates of breast cancer are still relatively high amongst women diagnosed at an early stage, identifying women at high risk of recurrence at their time of diagnosis is important. hPG₈₀ is a promising new prognostic biomarker that could improve the identification of women at higher risk of poor outcomes.

Liquid biopsy at the frontier in renal cell carcinoma: recent analysis of techniques and clinical application

Renal cell carcinoma (RCC) is a major pathological type of kidney cancer and is one of the most common malignancies worldwide. The unremarkable symptoms of early stages, proneness to postoperative metastasis or recurrence, and low sensitivity to radiotherapy and chemotherapy pose a challenge for the diagnosis and treatment of RCC. Liquid biopsy is an emerging test that measures patient biomarkers, including circulating tumor cells, cell-free DNA/cell-free tumor DNA, cell-free RNA, exosomes, and tumor-derived metabolites and proteins. Owing to its non-invasiveness, liquid biopsy enables continuous and real-time collection of patient information for diagnosis, prognostic assessment, treatment monitoring, and response evaluation. Therefore, the selection of appropriate biomarkers for liquid biopsy is crucial for identifying high-risk patients, developing personalized therapeutic plans, and practicing precision medicine. In recent years, owing to the rapid development and iteration of extraction and analysis technologies, liquid biopsy has emerged as a low cost, high efficiency, and high accuracy clinical detection method. Here, we comprehensively review liquid biopsy components and their clinical applications over the past 5 years. Additionally, we discuss its limitations and predict its future prospects.

hPG80 (circulating progastrin) as a blood biomarker for high-grade glial tumors: A pilot study

Background

Currently, the long-term prognosis and survival rate of patients with high-grade glial tumors remains poor and there are no biomarkers. hPG₈₀ (circulating progastrin) secreted into the blood by tumor cells has been widely studied in colorectal cancer. Its involvement in tumorigenesis has been demonstrated in the literature. Moreover, according to a recent study, hPG₈₀ is expressed in the blood of cancer patients at a significantly higher concentration than in the control group composed of healthy blood donors.

Methods

The PROGLIO study is a pilot, single-center, longitudinal study that primarily seeks to evaluate circulating plasma hPG₈₀ concentrations over time in patients with high-grade glial tumors. A fasting blood sample will be taken on the start and end day of radiotherapy and during the adjuvant chemotherapy (every 3 cycles). Follow-up monitoring will be performed for 9 months, with a blood sample taken every 3 months on the day of the follow-up MRI. The study plans to recruit 30 patients and recruitment started in February 2022.

Trial registration

ClinicalTrials.gov, ID NCT05157594; registered on October 27, 2021.

[hPG80 and cancer: A new blood biomarker in development for patient monitoring]

Recent technological advances coupled with our improved understanding of the molecular and cellular mechanisms associated with cancer development have enabled better overall patient care. Among the newly identified biomarkers such as circulating tumor DNA or circulating tumor cells, hPG₈₀ (circulating progastrin) that is easy to detect and quantify by a simple ELISA assay has the potential to become a new routine clinical tool in oncology if on-going studies validated its utility. Indeed, on the one hand, hPG₈₀ was found in the blood of patients with different tumors (colorectal, pancreatic, liver, lung, stomach, kidney cancers) at a significantly higher concentration than in healthy donors. Moreover, some studies suggested a potential association between hPG₈₀ concentration changes and anti-cancer treatment efficacy in patients with gastro-intestinal and hepatocellular carcinomas. Finally, hPG₈₀ might be a prognostic factor for overall survival in metastatic renal cell carcinoma cancer (mRCC) and in hepatocellular carcinoma (HCC). If these hypotheses were validated, hPG₈₀ might help better stratify patients according to their prognosis, and also become a tool to monitor relapse and predict treatment response. Prospective validation studies are on-going.

hPG80 (Circulating Progastrin), a Novel Blood-Based Biomarker for Detection of Poorly Differentiated Neuroendocrine Carcinoma and Well Differentiated Neuroendocrine Tumors

Simple Summary

Current blood-based biomarkers for neuroendocrine neoplasms (NENs) lack both sensitivity and specificity. Human circulating progastrin (hPG₈₀) can be easily measured in plasma by ELISA. This study is the first to examine hPG₈₀ in NENs. The study demonstrated increased levels of hPG₈₀ in all sub-types of NENs, with a high sensitivity and specificity demonstrated. Plasma hPG₈₀ in NENs may be a diagnostic blood biomarker for both low- and high-grade NENs; further study is warranted. A prospective multi-center trial is ongoing in NET to evaluate hPG₈₀ as a means of monitoring disease (NCT04750954).

Abstract

Current blood-based biomarkers for neuroendocrine neoplasms (NENs) lack both sensitivity and specificity. Human circulating progastrin (hPG₈₀) is a novel biomarker that can be easily measured in plasma by ELISA. This study is the first to examine hPG₈₀ in NENs. Plasma hPG₈₀ was quantified from 95 stage IV NEN patients, using DxPG₈₀ technology (ECS Progastrin, Switzerland) and compared with hPG₈₀ concentrations in two cohorts of healthy donor controls aged 50–80 (n = 252) and 18–25 (n = 137). Median hPG₈₀ in NENs patients was 5.54 pM compared to 1.5 pM for the 50–80 controls and 0.29 pM the 18–25 cohort (p < 0.0001). Subgroup analysis revealed median hPG₈₀ levels significantly higher than for either control cohort in neuroendocrine carcinoma (NEC; n = 25) and neuroendocrine tumors (NET; n = 70) including the small-cell lung cancer (SCLC) sub-cohort (n = 13). Diagnostic accuracy, estimated by AUCs, was high for NENs, as well as both sub-groups (NEC/NET) when compared to the younger and older control groups. Plasma hPG₈₀ in NENs may be a diagnostic blood biomarker for both low- and high-grade NENs; further study is warranted. A prospective multi-center trial is ongoing in NET to evaluate hPG₈₀ as a means of monitoring disease (NCT04750954).

Plasma hPG80 (Circulating Progastrin) as a Novel Prognostic Biomarker for Hepatocellular Carcinoma

Simple Summary

Liver cancer is the sixth most common cancer world-wide and hepatocellular carcinoma (HCC), the most common form of primary liver cancer, accounts for 90% of the cases. The diagnosis of HCC is usually based on non-invasive criteria using detection of a liver nodule in abdominal ultrasonography or high serum alpha-fetoprotein (AFP) levels. However, as it is only elevated in 60% of patients with HCC, AFP has limited accuracy, especially in early stages, as both a diagnostic and prognostic test. We investigated hPG80 (circulating progastrin), which is associated with liver cancer biology, and found that hPG80 levels is both an independent prognostic marker in HCC and used in combination with AFP, it improves the stratification of the patients in good and poor prognosis, especially for those patients at early-stage. This will help stratify HCC patients more accurately in the future and improve the management of these patients.

Abstract

Alpha-fetoprotein (AFP) is the most widely used biomarker for hepatocellular carcinoma (HCC) prognosis. However, AFP is not useful in establishing a prognosis for patients with a tumor in the early stages. hPG₈₀ (circulating progastrin) is a tumor promoting peptide present in the blood of patients with various cancers, including HCC. In this study, we evaluated the prognostic value of plasma hPG₈₀ in patients with HCC, alone or in combination with AFP. A total of 168 HCC patients were tested prospectively for hPG₈₀ and analyzed retrospectively. The prognostic impact of hPG₈₀ and AFP levels on patient survival was assessed using Kaplan-Meier curves and log-rank tests. hPG₈₀ was detected in 84% of HCC patients. There was no correlation between hPG₈₀ and AFP levels in the training and validation cohorts. Both cohorts showed higher sensitivity of hPG₈₀ compared to AFP, especially at early stages. Patients with high hPG₈₀ (hPG₈₀+) levels (optimal cutoff value 4.5 pM) had significantly lower median overall survival (OS) compared to patients with low hPG₈₀ (hPG₈₀−) levels (12.4 months versus not reached respectively, p < 0.0001). Further stratification by combining hPG₈₀ and AFP levels (cutoff 100 ng/mL) improved prognosis in particular for those patients with low AFP level (hPG₈₀−/AFP+ and hPG₈₀−/AFP−, 13.4 months versus not reached respectively, p < 0.0001 and hPG₈₀+/AFP+ and hPG₈₀+/AFP−, 5.7 versus 26 months respectively, p < 0.0001). This was corroborated when analyses were performed using the BCLC staging especially at early stages. Our findings show that hPG₈₀ could serve as a new prognostic biomarker in HCC. Used in combination with AFP, it improves the stratification of the patients in good and poor prognosis, especially for those patients with negative AFP and early-stage HCC.