Colorectal cancer and dormant metastases:Put to sleep or destroy?

After reading the review by An et al“Biological factors driving colorectal cancer metastasis”,which covers the problem of the metastasis of colorectal cancer(CRC),I had a desire to discuss with readers one of the exciting problems associated with dormant metastases.Most deaths from CRCs are caused by metastases,which can be detected both at diagnosis of the primary tumor and several years or even decades after treatment.This is because tumor cells that enter the bloodstream can be destroyed by the immune system,cause metastatic growth,or remain dormant for a long time.Dormant tumor cells may not manifest themselves throughout a person’s life or,after some time and under appropriate conditions,may give rise to the growth of metastases.In this editorial,we will discuss the most important features of dormant metastases and the mechanisms of premetastatic niche formation,as well as factors that contribute to the activation of dormant metastases in CRCs.We will pay special attention to the possible mechanisms involved in the formation of circulating tumor cell complexes and the choice of therapeutic strategies that promote the dormancy or destruction of tumor cells in CRCs.

Clinical and pathological characteristics and expression of related molecules in patients with airway disseminated lung adenocarcinoma

Objective:Lung adenocarcinoma exhibits diverse genetic and morphological backgrounds,in addition to considerable differences in clinical pathology and molecular biological characteristics.Among these,the phenomenon of spread through air space(STAS),a distinct mode of lung cancer infiltration,has rarely been reported.Therefore,this study aimed to explore the relationship between STAS tumor cells and the clinical and molecular characteristics of patients with lung adenocarcinoma,as well as their impact on prognosis.Methods:This study included 147 patients who were diagnosed with lung adenocarcinoma at the Inner Mongolia Autonomous Region Cancer Institute between January 2014 and December 2017.Surgical resection specimens were retrospectively analyzed.Using univariate and multivariate Cox analyses,we assessed the association between STAS and the clinicopathological features and molecular characteristics of patients with lung adenocarcinoma.Furthermore,we investigated the effects on patient prognosis.In addition,we developed a column–line plot prediction model and performed internal validation.Results:Patients with positive STAS had a significantly higher proportion of tumors with a diameter≥2 cm,with infiltration around the pleura,blood vessels,and nerves,and a pathological stage>IIB than in STAS-negative patients(P<0.05).Cox multivariate survival analysis revealed that clinical stage,STAS status,tumor size,and visceral pleural invasion were independent prognostic factors influencing the 5-year progression-free survival in patients with lung adenocarcinoma.The predictive values and P values from the Hosmer-Lemeshow test were 0.8 and 0.2,respectively,indicating no statistical difference.Receiver operating characteristic curve analysis demonstrated areas under the curve of 0.884 and 0.872 for the training and validation groups,respectively.The nomogram model exhibited the best fit with a value of 192.09.Conclusions:Clinical stage,pleural invasion,vascular invasion,peripheral nerve invasion,tumor size,and necrosis are independent prognostic factors for patients with STAS-positive lung adenocarcinoma.The nomogrambased on the clinical stage,pleural invasion,vascular invasion,peripheral nerve invasion,tumor size,and necrosis showed good accuracy,differentiation,and clinical practicality.

Detection of disseminated pancreatic cells by amplification of cytokeratin-19 with quantitative RT-PCR in blood,bone marrow and peritoneal lavage of pancreatic carcinoma patients

AIM： To evaluate the diagnostic potential of cytokeratin-19 （CK-19） mRNA for the detection of disseminated tumor cells in blood, bone marrow and peritoneal lavage in patients with ductal adenocarcinoma of the pancreas. METHODS： Sixty-eight patients with pancreatic cancer （/7 = 37）, chronic pancreatitis （n = 16）, and non-pancreatic benign surgical diseases （/7 = 15, control group） were included in the study. Venous blood was taken preoperatively, intraoperatively and at postoperative d 1 and 10. Preoperative bone marrow aspirates and peritoneal lavage taken before mobilization of the tumor were analyzed. All samples were evaluated for disseminated tumor cells by CK-19-specific nested-PCR and quantitative fluorogenic RT-PCR. RESULTS： CK-19 mRNA expression was increased in 24 （64%） blood samples and 11 （30%） of the peritoneal lavage samples in the patients with pancreatic cancer. In 15 （40%） of the patients with pancreatic cancer, disseminated tumor cells were detected in venous blood and bone marrow and/or peritoneal lavage. In the peritoneal lavage, the detection rates were correlated with the tumor size and the tumor differentiation. CK-19 levels were increased in pT3/T4 and moderately/poorly differentiated tumors （G2/G3）. Pancreatic cancer patients with at least one CK-19 mRNA-positive sample showed a trend towards shorter survival. Pancreatic cancer patients showed significantly increased detection rates of disseminated tumor cells in blood and peritoneal lavage compared to the controls and the patients with chronic pancreatitis. CONCLUSION： Disseminated tumor cells can be detected in patients with pancreatic ductal adenocarcinorna by CK-19 fluorogenic RT-PCR. In peritoneal lavage, detection rate is correlated with tumor stage and differentiation. In the clinical use, CK-19 is suitable for the distinction between malignant and benign pancreatic disease in combination with other tumor-specific markers.

Molecular biomarkers for the detection of metastatic colorectal cancer cells

Approximately half of all patients with colorectal cancer develop local recurrence or distant metastasis during the course of their illness. Recently, the molecular detection of metastatic cancer cells in various types of clinical samples, such as lymph nodes, bone marrow, peripheral blood, and peritoneal lavage fluid, has been investigated as a potential prognostic marker. The prognostic value of molecular tumor cell detection was independent of the type of detection method used. As assays become more sensitive and quantitative, a more thorough assessment of the cancer status of patients will be based on molecular markers alone. At present, it is difficult to conclude that one specific molecular marker is superior to others. Comparative analyses are recommended to assess the prognostic impact of molecular analyses in the same patient and determine the biomarkers that provide the most accurate prognostic information.

Mapping bone marrow niches of disseminated tumor cells

Breast cancer cells may disseminate early, before tumor diagnosis. Disseminated tumor cells, or DTCs, reside in the bone marrow, and may persist for years or even decades. Some of these cells may be re-activated to resume aggressive growth, and eventually become overt bone metastases. Recent studies have begun to shed light on this complicated process and revealed multiple steps and intermediate states of colonizing DTCs. However, how cancer-host interactions evolve during this process needs to be further understood. Most of our current knowledge of the bone microenvironment is obtained through studies looking for the hematopoietic stem cell(HSC) niche. Although this long-standing question has not yet been resolved, our search for the HSC niche has resulted in a detailed map of various cell types in the bone marrow. Furthermore, various techniques used to find the HSC niche may also be adapted for finding the cancer cell niche. In this article, we will review the recent progress in both the DTC and HSC areas with a focus on their potential microenvironment niches. We will also discuss how to apply what we have learned from HSC studies to map DTCs in the bone context. We hope to stimulate thoughts and ideas to further elucidate the bone colonization process, and develop potential therapeutic interventions.

Prognostic relevance of minimal residual disease in colorectal cancer

Presence of occult minimal residual disease in patients with colorectal cancer(CRC)has a strong prognostic impact on survival.Minimal residual disease plays a major role in disease relapse and formation of metastases in CRC.Analysis of circulating tumor cells(CTC)in the blood is increasingly used in clinical practice for disease monitoring of CRC patients.In this review article the role of CTC,disseminated tumor cells(DTC)in the bone marrow and micrometastases and isolated tumor cells(ITC)in the lymph nodes will be discussed,including literature published until September 2013.Occult disease is a strong prognostic marker for patient survival in CRC and defined by the presence of CTC in the blood,DTC in the bone marrow and/or micrometastases and ITC in the lymph nodes.Minimal residual disease could be used in the future to identify patient groups at risk,who might benefit from individualized treatment options.

Phase I Dose Escalation Study with the Lewis Y Carbohydrate Specific Humanized Antibody IGN311

Purpose: Investigation of safety, tolerability, pharmacokinetics, and anti-tumor activity of the Lewis Y-specific, fully humanized monoclonal antibody (mAb) IGN311 in patients with Lewis Y positive tumors in a Phase I clinical trial. Experimental Design: Twelve patients (pts) were enrolled in an open-label, uncontrolled, dose escalating Phase I study. Three pts received 50 mg, three pts 100 mg and six pts 200 mg IGN311 by i.v. infusion on days 1 and 15. Blood samples were taken immediately before infusion, and 0.5, 4, 8, 24 hours post infusion, as well as on days 3, 5 and 8 after the first and second infusion, respectively, and day 29. A final visit was scheduled for day 43. Results: No drug related adverse events were observed in the 50 mg and 100 mg dose groups. Three out of six patients in the 200 mg dose group showed drug related adverse reactions with nausea, vomiting and hypotension in one patient (NCI CTC grade 3) being the dose limiting toxicities. t1/2 of IGN311 was ~20 days after second infusion of IGN311. Sera of patients receiving IGN311 were capable of lysing Lewis Y positive tumor cells in vitro by both, complement-dependent cytotoxicity (CDC) and antibody-dependent cellular cytotoxicity (ADCC). Circulating tumor cells found in the peripheral blood in two out of twelve pts prior to treatment were reduced after treatment to below the quantification limit of the detection method. None of the patients showed an increase in the number of disseminated tumor cells during treatment period. Conclusions: The good safety and PK profile, the biological activity regarding CDC and ADCC mediated tumor cell lysis, and the elimination of circulating tumor cells warrant further clinical investigation of IGN311.

Liquid biopsy in metastatic breast cancer

The spread of single tumor cells shed by the primary tumor has been observed in most solid carcinomas and is generally associated with poor clinical outcome.Tumor cells detected in the peripheral blood are commonly referred to as circulating tumor cells(CTCs)and are seen as possible precursors of metastatic disease.Beyond CTCs,circulating tumor DNA and non-coding RNA are increasingly the focus of translation cancer research.In metastatic breast cancer(MBC),elevated levels of CTCs have been confirmed as an independent prognostic factor.While detection of elevated counts after the start of systemic therapy predicts poor response,it is unclear which treatment strategy should be offered in the case of CTC persistence.Currently,the main potentials of blood-based diagnostics in BC are therapy monitoring and liquid biopsy-based treatment interventions.Recently,the first positive study on CTC-guided therapy choices in hormone receptor positive HER2 negative MBC was published.In the present review,we discuss the current data and potential clinical application of liquid biopsy in the metastatic setting.