Clinical impact of different detection methods for disseminated tumor cells in bone marrow of patients undergoing surgical resection of colorectal liver metastases: a prospective follow-up study

Presence of bone marrow micro-metastases in stage I-III colon cancer patients is associated with worse disease-free and overall survival

The prognostic significance of bone marrow micro-metastases (BMM) in colon cancer patients remains unclear. We conducted a prospective cohort study with long-term follow-up to evaluate the relevance of BMM as a prognostic factor for disease free (DFS) and overall survival (OS) in stage I-III colon cancer patients. In this prospective multicenter cohort study 144 stage I-III colon cancer patients underwent bone marrow aspiration from both iliac crests prior to open oncologic resection. The bone marrow aspirates were stained with the pancytokeratin antibody A45-B/B3 and analyzed for the presence of epithelial tumor cells. DFS and OS were analyzed using a Cox proportional hazard model and robust standard errors to account for clustering in the multicenter setting. Median overall follow-up was 6.2 years with no losses to follow-up, and 7.3 years in patients who survived. BMM were found in 55 (38%) patients. In total, 30 (21%) patients had disease recurrence and 56 (39%) patients died. After adjusting for known prognostic factors, BMM positive patients had a significantly worse DFS (hazard ratio [HR] 1.33; 95% confidence interval [95% CI]: 1.02-1.73; P = 0.037) and OS (HR 1.30; 95% CI: 1.09-1.55; P = 0.003) compared to BMM negative patients. Bone marrow micro-metastases occur in over one third of stage I-III colon cancer patients and are a significant, independent negative prognostic factor for DFS and OS. Future trials should evaluate whether node-negative colon cancer patients with BMM benefit from adjuvant chemotherapy.

Micrometastasis in colorectal cancer: does it affect staging?

BACKGROUND

Micrometastasis (MM) in colorectal cancer (CRC) is not considered in tumour-node-metastasis (TNM) staging currently and also the prognostic significance of these occult tumoural cells is not proven yet. This study was designed to find whether MM to bone marrow (BM) and/or liver cause upstaging of the tumour according to conventional staging system and if it may alter the survival rate.

METHODS

Thirty-eight CRC patients who were candidates of surgical procedure were enrolled in our cross-sectional study. Liver and BM biopsy were obtained during the surgery to be looked for tissue-specific marker of CRC, CK20. CK20 expression in BM and liver was assessed by the two methods of reverse transcriptase polymerase chain reaction and immunohistochemistry.

RESULTS

Among the 38 submitted patients, a total number of 14 MM, including 10 BM (23%) and seven hepatic (18%) were detected. There was no significant difference in clinicopathological aspects including size, location, stage, grade, local invasion to vessels and neurons, TNM staging and relapse rate of tumour among patients with/without disseminated tumoural cells. The result did not demonstrate a survival difference between patients receiving neoadjuvant chemotherapy compared to other patients.

CONCLUSION

Our study did not confirm that the presence of MM influences TNM staging and overall survival of the patients. Additional clinical investigations with longer follow-up period and larger number of cases are required to decide on administration of neoadjuvant therapy in CRC patients.

Molecular markers of prognosis and therapeutic targets in metastatic colorectal cancer

Metastatic disease ultimately occurs in approximately 50-70% of patients presenting with colorectal cancer. In patients with advanced disease, there is significant variability in individual patient outcomes. To improve understanding of tumor behavior, markers such as KRAS and BRAF mutation status are increasingly utilized. Additionally, newer surrogates of tumor biology, such as telomerase activity and the prevalence of circulating tumor cells and circulating tumor DNA, have generated increasing interest due to clinical potential. While the extent to which these newer markers can predict outcome and guide therapy is yet to be determined, KRAS mutation status is currently used to guide systemic therapy in selected patients. Furthermore, advances in our understanding of various tumorigenic pathways (such as the mitogen activated protein kinase pathway) have enabled newer targeted agents, including BRAF inhibitors. Interestingly, although inhibition of BRAF in patients has not translated into improved outcomes, characterization of BRAF mutations led to an association with microsatellite instability. A unique histologic characteristic of certain tumors in patients with microsatellite instability is the infiltration by lymphocytes at the tumor-stromal interface. This feature highlights the biology of the tumor in its microenvironment and underlies the efficacy of the programmed-death inhibitor, pembrolizumab, in patients with microsatellite unstable metastatic colorectal cancer. With an increasing number of prognostic markers and therapeutic options in metastatic colorectal cancer, the multidisciplinary approach becomes critical for appropriate treatment decisions.

Central, But Not Peripheral, Circulating Tumor Cells are Prognostic in Patients Undergoing Resection of Colorectal Cancer Liver Metastases

BACKGROUND

Colorectal cancer liver metastases (CRLMs) are potentially curable with resection, but most patients recur and succumb to their disease. Clinical covariates do not account for all outcomes. Circulating tumor cells (CTCs) are prognostic in the primary and metastatic settings of breast, prostate and colorectal cancer (CRC), and evolving evidence supports their role in CRLMs. Our objective was to determine whether CTCs in peripheral (PV) and hepatic venous (HV) compartments are associated with disease-free survival (DFS) and overall survival (OS) post-CRLM resection.

METHODS

CTCs were measured by CellSearch assay from intraoperative HV and PV samples from 63 patients who underwent CRLM resection from June 2007 to August 2012 at a single center. DFS and OS were primary endpoints.

RESULTS

HV CTCs > 3 were associated with shorter DFS and OS, but not PV CTCs, although no significant difference was found between CTC measurements in the two compartments. By univariate analysis, CRC stage and site, CRLM recurrence, and hepatic capsule invasion were also associated with OS, but only HV CTCs and CRC site were significant by multivariate Cox. Only HV CTCs were associated with DFS by multivariate analysis. Cases with elevated HV CTCs had hepatic vein invasion and lymph node metastases, and were younger with larger tumors.

CONCLUSIONS

Elevated HV CTCs are prognostic for DFS and OS following CRLM resection. Clinicopathologic features associated with HV CTCs are identifiable preoperatively and should be considered in CRLM surgical decision making. We found no evidence that PV CTCs are prognostic in this setting.

Rectal Carcinoma Case Causing Bicytopenia

Although conditions leading to bicytopenia and pancytopenia secondary to infiltrative diseases of the bone marrow are seen, a profound anemia or hemorrhages are frequently observed in such cases. As bone marrow infiltrations may be associated with primary hematological diseases such as leukemia, lymphoma or myeloma, rarely they may also be associated with solid tumor metastases. Here we have presented a case of rectal carcinoma causing profound bicytopenia dependent on diffuse bone marrow involvement.

Surgery for colorectal liver metastases: The evolution of determining prognosis

Despite improvements in the multi-modality treatment of colorectal liver metastasis (CRLM), survival after resection remains varied. Determining prognosis after surgical resection has historically been predicated on preoperative clinicopathological factors such as primary tumor stage, carcinoembryonic antigen levels, number of liver metastases, presence of extrahepatic disease, as well as other factors. While scoring systems have been developed by combining certain preoperative factors, these have been inconsistent in accurately determining prognosis. There has been increasing interest in the use of biologic and molecular markers to predict prognosis following CRLM. The role of markers such as KRAS, BRAF, p53, human telomerase reverse transcriptase, thymidylate synthase, Ki-67, and hypoxia inducible factor-1α and their correlation with accurately predicting survival after surgical resection have been supported by several studies. Furthermore, other elements such as pathological response to chemotherapy and the presence of circulating tumor cells have shown promise in accurately determining prognosis after resection for colorectal liver metastasis. We herein review past, present, and possible future markers of prognosis among colorectal cancer patients with liver metastasis undergoing resection with curative intent.

Prognostic significance of isolated tumor cells in patients with colorectal cancer in recent 10-year studies

Circulating tumor cells (CTCs) that detach from the primary tumor and move into the circulation are detected in patients with metastatic cancer. The discovery of such cancer cells has been used as a predictor of recurrence and prognosis, although a consensus regarding such applications has not been reached. Peritoneal cytology may be used for identifying high risk of recurrence or mortality, whereas the intraoperative presence of tumor cells in drainage veins, bone marrow, or the liver is not always useful for evaluating the prognosis. The reported positive rate for tumor cells in the peripheral blood of patients with colorectal cancer, including metastasis, has varied from 10 to 80%; however, numerous studies have demonstrated significant differences in the recurrence and mortality rates between patients with and without isolated tumor cells (ITCs) in the peripheral blood. However, the clinical significance of CTCs as an absolute prognostic factor has not been elucidated, since the measurement methodologies and/or the number of cases differed between the studies. Future prospective studies including larger patient populations may elucidate the utility of routine detection of ITCs in daily practice.

Circulating tumor cells and prognosis of patients with resectable colorectal liver metastases or widespread metastatic colorectal cancer: a meta-analysis

BACKGROUND

We performed a systematic review and meta-analysis to investigate the prognostic value of tumor cells in blood (circulating tumor cells [CTCs]) or bone marrow (BM) (disseminated tumor cells) of patients with resectable colorectal liver metastases or widespread metastatic colorectal cancer (CRC).

MATERIALS AND METHODS

The following databases were searched in May 2011: MEDLINE, EMBASE, Science Citation Index, BIOSIS, Cochrane Library. Studies that investigated the association between tumor cells in blood or BM and long-term outcome in patients with metastatic CRC were included. We extracted hazard ratios (HRs) and confidence intervals (CIs) from the included studies and performed random-effects meta-analyses for survival outcomes.

RESULTS

The literature search yielded 16 studies representing 1,491 patients. The results of 12 studies representing 1,329 patients were suitable for pooled analysis. The overall survival (HR, 2.47; 95 % CI 1.74-3.51) and progression-free survival (PFS) (HR, 2.07; 95 % CI 1.44-2.98) were worse in patients with CTCs. The subgroup of studies with more than 35 % CTC-positive patients was the only subgroup with a statistically significant worse PFS. All eight studies that performed multivariable analysis identified the detection of CTCs as an independent prognostic factor for survival.

CONCLUSION

The detection of CTCs in peripheral blood of patients with resectable colorectal liver metastases or widespread metastatic CRC is associated with disease progression and poor survival.

[Disseminated and circulating tumor cells in gastrointestinal oncology]

Circulating (CTC) and disseminated tumor cells (DTC) represent two different steps of the metastatic process. As with other types of cancer, the recent development of techniques for the detection of CTC and DTC respectively in the blood and bone marrow of patients generated many results in digestive cancers. However, the interpretation of these results and of the prognostic value of CTC/DTC is often limited by the small cohort size and the heterogeneity of detection methods. The aim of this article is to review the different results and their clinical impact, and discuss the possible use of CTC and DTC as new biomarkers. First of all, it is important to take into account the variability of epithelial markers used for the initial stage of immunoselection of CTC/DTC as well as that of molecular or cytological markers used for the second stage of detection. In esophageal, gastric, pancreatic and hepatocellular carcinomas, and in the ileal and pancreatic neuroendocrine tumors, some studies showed a correlation between the detection of CTC and/or DTC and a clinical pejorative course, whether these tumors were at localized or metastatic stages. On colorectal cancer in the adjuvant setting, a recent meta-analysis showed an association between the detection of CTC in peripheral blood and disease-free survival or overall survival. These results are consistent with those of a study that identified detection of CTC as a prognostic factor for relapse in stage II. This last study concluded that it was necessary to achieve long-term evaluation of CTC as a biomarker to guide the decisions of chemotherapy for stage II. In metastatic colorectal cancer, the FDA approved in 2007 the use of pretherapeutic levels of CTC and its variations per-treatment, determined by CellSearch(®) technology, as a tool in treatments management. However, the modalities of this monitoring have to be specified and clinical benefit or the cost-effectiveness of a treatment based on this new biomarker has to be evaluated. Finally, the qualitative and quantitative monitoring of CTC could be a non-invasive tool to monitor changes in tumor biology throughout the disease, and thereby improve the understanding of the processes of dissemination and therapeutic resistance.

Disseminated tumor cells in the bone marrow negatively influence survival after resection of colorectal liver metastases

BACKGROUND

Despite all efforts in extending the resectability rates of colorectal liver metastases, thus improving the prognosis of the patients, tumor recurrence occurs in many patients. Occult dissemination of tumor cells might reflect a minimal residual disease that is not eliminated by primary surgery. Because the prognostic effect of disseminated tumor cells (DTC) is still uncertain in this clinical setting, we analyzed these cells in the peripheral blood and bone marrow of patients undergoing hepatic resection of colorectal liver metastases.

METHODS

In 108 patients with colorectal liver metastases, the presence of DTC in the peripheral blood and bone marrow was detected with CK20 RT-PCR. Clinical data were prospectively collected, and multiple variables were analyzed regarding their influence on overall survival.

RESULTS

DTC in the peripheral blood were detected in 40% of the patients. In 25% of the patients, DTC were detected in the bone marrow. The median follow-up was 34 months. Fifty-nine of 108 patients died from tumor relapse. Multivariate analysis determined detection of DTC in the bone marrow to be an independent prognostic factors for overall survival (P = 0.038).

CONCLUSIONS

This large series of patients with hepatic resection of colorectal liver metastases demonstrated that detection of CK20-positive DTC via RT-PCR in the bone marrow compartment negatively influences overall survival. The evidence of DTC in the bone marrow might serve as an additional individual marker to select patients for adjuvant treatment after liver metastases resection.

Biology and significance of circulating and disseminated tumour cells in colorectal cancer

PURPOSE

More than 130 years ago, circulating tumour cells (CTCs) and disseminated tumour cells (DTCs) have been linked to metastasis. Since then, a myriad of studies attempted to characterise and elucidate the clinical impact of CTCs/DTCs, amongst others in colorectal cancer (CRC). Due to a flood of heterogeneous findings regarding CTCs/DTCs in CRC, this review aims to describe the known facts about CTC/DTC biology and clinical impact.

METHODS

To identify the basic scientific literature regarding the biology and clinical impact of CTCs/DTCs in CRC, we reviewed the literature in the PubMed database. We focused on publications written in English and published until January 2012. As search terms, we used "colorectal cancer (CRC)", "colon cancer (CC)", "CTC", "DTC", "bone marrow (BM)", "lymph node (LN)", "peripheral blood (PB)", "significance" and "prognosis".

RESULTS

CTC detection and quantification under standardised conditions is feasible. Several studies in large patient settings have revealed prognostic impact of CTCs in CRC. CRC-derived DTC detection and analysis in BM exhibits a more heterogeneous picture but also shows clinical value. Furthermore, the presence of DTCs in LN has a strong prognostic impact in CRC.

CONCLUSIONS

Clinical relevance and prognostic significance of CTCs/DTCs in CRC have been clearly demonstrated in many experimental studies. The major challenge in CTC/DTC research is now to harmonise the various identification and detection approaches and consequently to conduct large prospective multi-institutional trials to verify the use of CTCs/DTCs as a valid prognostic and predictive biomarker for clinical routine.

Predictors of long-term survival in patients with colorectal liver metastases: a single center study and review of the literature

PURPOSE

Prognosis after resection of liver metastases of colorectal cancer is influenced by a variety of clinical factors. For more than 20 years, efforts have been made to restructure and simplify prognostic parameters into clinical scores. We evaluated the influence of various clinical and pathological factors on survival and recurrence and developed a simple model for risk stratification.

METHODS

We have analyzed a total of 13 prognostic factors in 382 consecutive and prospectively enrolled R0-resected patients and applied our data set to ten published prognostic scoring systems. Prognostic factors that influenced disease-specific and disease-free survival were included into a model clinical risk score.

RESULTS

The 5- and 10-year observed survival rates were 43% and 28%, respectively, for all 382 patients. The disease-specific 5- and 10-year survival rates were 49% and 37%, respectively; the 5- and 10-year recurrence rates were 68% and 70%, respectively. For patients with synchronous liver metastases, survival was not affected by the timing of liver resection. The prognosis after treatment of any recurrence was best after the accomplishment of a repeated R0 situation, independent of the location of the recurrence. In the multivariate analysis, the disease-specific survival and recurrence rates were statistically significantly influenced by more than three lymph node metastases of the primary tumor, more than two lesions within the liver, and the presence of extrahepatic tumor.

CONCLUSIONS

From these data, we have developed a simple score for the risk stratification which may be useful for future studies on interdisciplinary management of colorectal liver metastases.

Disseminated and circulating tumor cells in gastrointestinal oncology

Circulating (CTCs) and disseminated tumor cells (DTCs) are two different steps in the metastatic process. Several recent techniques have allowed detection of these cells in patients, and have generated many results using different isolation techniques in small cohorts. Herein, we review the detection results and their clinical consequence in esophageal, gastric, pancreatic, colorectal, and liver carcinomas, and discuss their possible applications as new biomarkers.

The detection of disseminated tumor cells in bone marrow and peripheral blood of gastric cancer patients by multimarker (CEA, CK20, TFF1 and MUC2) quantitative real-time PCR

OBJECTIVE

To investigate the suitability of multimarker detection of DTCs in PB and BM of GC patients.

DESIGN AND METHOD

A qRT-PCR assay was developed to estimate the number of CEA, CK20, TFF1 and MUC2 transcripts in PB and BM samples of 35 GC patients prior to the initiation of therapy. PB samples from healthy volunteers and BM from patients with hematological malignancies were used as negative controls.

RESULTS

In PB analysis; 22.9%, 37.1%, 31.4%, and 22.9% of GC patients and in BM analysis; 20%, 28.6%, 45.7%, and 22.9% of GC patients were positive for CEA, CK20, TFF1 and MUC2 mRNAs, respectively. Samples from the control group were negative for the expression of all the markers tested in this study. A higher positive ratio was obtained with the multimarker detection in comparison to the single marker detection. There was a significant correlation between the PB and BM samples for DTC detection.

CONCLUSION

Multimarker detection assay is a reliable and powerful tool for the early detection of DTCs in GC patients.