Combined DNA Analysis from Stool and Blood Samples Improves Tumor Tracking and Assessment of Clonal Heterogeneity in Localized Rectal Cancer Patients.

Objectives: In this study, stool samples were evaluated for tumor mutation analysis via a targeted next generation sequencing (NGS) approach in a small patient cohort suffering from localized rectal cancer. Introduction: Colorectal cancer (CRC) causes the second highest cancer-related death rate worldwide. Thus, improvements in disease assessment and monitoring that may facilitate treatment allocation and allow organ-sparing "watch-and-wait" treatment strategies are highly relevant for a significant number of CRC patients. Methods: Stool-based results were compared with mutation profiles derived from liquid biopsies and the gold standard procedure of tumor biopsy from the same patients. A workflow was established that enables the detection of de-novo tumor mutations in stool samples of CRC patients via ultra-sensitive cell-free tumor DNA target enrichment. Results: Notably, only a 19% overall concordance was found in mutational profiles across the compared sample specimens of stool, tumor, and liquid biopsies. Conclusion: Based on these results, the analysis of stool and liquid biopsy samples can provide important additional information on tumor heterogeneity and potentially on the assessment of minimal residual disease and clonal tumor evolution.

Organ sparing management in rectal cancer. Are we there yet?

BACKGROUND: The "watch and wait" approach has recently been proposed as an alternative to surgery in locally-advanced rectal cancer patients that respond to neo-adjuvant chemoradiotherapy, in order to decrease its negative functional consequences upon the quality of life of these patients. Current methods show low accuracy for the identification of complete responders. MATERIALS AND METHODS: A review of the literature was conducted for articles published up to March 31th, 2019. Relevant studies were identified using bibliographic searches of Pubmed database. The keywords that were used in various combinations were: "neoadjuvant chemoradiotherapy", "non-operative management", "complete pathological response", "rectal cancer", "biomarkers", "staging". RESULTS: Magnetic resonance imaging can identify complete responders with a high accuracy using new protocols like diffusion weighted imaging. Positron emission tomography with 18-fluoro-deoxy-glucose shows a sensitivity of 90.9% and specificity of 80.3% for the prediction of complete pathologic response using the change in standardized uptake value. A panel of 15 metabolites was identified and shows potential to discriminate patient resistance and sensitivity to neo-adjuvant therapy (Area Under the Curve 0.80). Furthermore, pre-treatment peripheral blood neutrophil to lymphocyte ratio below 2 and platelet to lymphocyte ratio below 133.4 are significantly correlated with good tumor response (OR 2.49). Analysis of the pattern of carcinoembryonic antigen (CEA) clearance after neoadjuvant treatment conclude that an exponential decrease of the CEA levels is associated with significant tumor down staging and complete pathologic response. CONCLUSION: New methods of assessing the response to neo-adjuvant therapy in locally-advanced rectal cancer have emerged, showing promising results. Further studies need to assess the best combination between imaging and these biomarkers in order to increase the accuracy and standardize the criteria for non-operative management. KEY WORDS: Biomarkers, Complete pathologic response, Non-Operative management, Rectal cancer, Staging.

The Assessment of Clinical Usage and Prognostic Value of YKL-40 Serum Levels in Patients With Rectal Cancer Without Distant Metastasis.

BACKGROUND: Colorectal cancer is one of the most common and significant malignancies in the world. YKL-40 (chitinase-3-like protein 1) is involved in cell proliferation, migration, inflammation, and tissue remodeling; and serum levels of YKL-40 are associated with patient outcome in various cancers. The aim of this study was to assess the potential clinical usage of YKL-40 pretreatment serum levels as a prognostic biomarker in rectal cancer. METHODS: Concentrations of YKL-40 and standard tumor marker-Carcinoembryonic antigen (CEA)-were assessed in serum of 83 patients with rectal cancer without distant metastasis, and association with clinicopathological characteristics and disease-free and overall survival was evaluated. RESULTS: Concentration of YKL-40 was significantly higher in serum of patients with rectal cancer compared to healthy controls ( P = .0001), and YKL-40 levels were able to predict rectal cancer (area under the Receiver Operating Characteristic [ROC] curve = .769) with higher accuracy than CEA (area under the ROC curve = .728) in patients with early stage disease. Increased YKL-40 levels were significantly associated with age ( P = .001); however, no association with other clinicopathological characteristics was observed. Finally, in patients with recurrence, the percentage of cases with increased concentration of YKL-40 was significantly higher than in patients without recurrence ( P = .041), and Kaplan-Meier analysis demonstrated that elevated YKL-40 concentration is a predictor of poor overall survival in patients with rectal cancer. CONCLUSION: Pretreatment serum levels of YKL-40 may be a novel prognostic factor of overall and disease-free survival in patients with nonmetastatic colorectal cancer.

Assessment of the value of carcinoembryonic antigen reduction ratio as a prognosis factor in rectal cancer.

BACKGROUND: Carcinoembryonic antigen (CEA) is the most widely used tumor marker for colorectal cancer. This study aimed to investigate the role of CEA reduction ratio after preoperative chemoradiotherapy (CRT). METHODS: We enrolled 284 patients who underwent preoperative CRT followed by radical surgical resection. Patients were divided into 3 groups: serum CEA levels before CRT (pre-CRT CEA) less than 5 ng/mL (group 1); pre-CRT CEA of 5 ng/mL or more with CEA reduction ratio of 50% or more (group 2); and pre-CRT CEA of 5 ng/mL or more with CEA reduction ratio less than 50% (group 3). RESULTS: The 5-year disease-free survival (DFS) rate was not different between groups 1 (71.8%) and 2 (69.4%) but was significantly lower in group 3 (49.5%). CEA group, lymph node status after CRT (ypN) stage, and histologic type were independent prognostic factors for DFS on multivariate analysis. CONCLUSIONS: CEA reduction ratio might be an independent prognostic factor for DFS in rectal cancer patients treated with preoperative CRT and radical surgery.

Vascular endothelial growth factor assessment in different blood fractions of gastrointestinal cancer patients and healthy controls.

Vascular endothelial growth factor (VEGF) is known to play a central role in tumour angiogenesis. Up to now inconclusive data have been published on the clinical-biological significance of circulating VEGF and on the most suitable blood fraction for measuring it. The aims of this pilot study were to assess VEGF in blood compartments of 16 healthy control volunteers and 56 gastrointestinal cancer patients, prospectively collected, to identify the most suitable blood fraction for the determination of VEGF and to evaluate its possible clinical-biological significance. Samples of serum (S) and plasma (P) in both sodium citrate (SC) and sodium citrate-theophylline-adenosine-dipyridamole (CTAD) were collected from venous blood. After the centrifugation and separation methods VEGF levels were detected by ELISA in: S, plasma-platelets poor (P-PP), plasma-activated platelets rich (P-APR) and blood-lysed whole (B-LW). The best differentiation between healthy control volunteers and cancer patients in VEGF level was seen for P-APRCTAD (mean value: 278 pg/ml vs 77 pg/ml; p=0.0036 by t-test). No significant correlation among the blood fractions of VEGF analysed and clinical-pathological features was found. Our data suggest that P-APRCTAD blood fraction, obtained according to well standardised conditions, could represent the most suitable compartment for the assessment of VEGF. We suggest that VEGF levels in P-APRCTAD could play a role as an angiogenic marker of malignant gastrointestinal transformation. Further studies on a larger series of patients and healthy controls with the same experimental methodological conditions are required to confirm our preliminary conclusions.

Utility of routine postoperative laboratory studies in patients undergoing potentially curative resection for adenocarcinoma of the colon and rectum.

In an effort to lower healthcare costs, this study was undertaken to evaluate the utility of routine postoperative (PO) laboratory studies and determine whether abnormalities alter patient (PT) care. This was a retrospective review of 105 PTs undergoing elective curative resection for colorectal cancer. A serum electrolyte and liver panel and a hematologic panel were drawn in all PTs. OF 8749 total laboratory values obtained, 5894 (67%) were normal. Two of these (0.03%) elicited a therapeutic intervention. Of the 2004 values that were low (23%), 103 (5.1%) elicited a therapeutic response. Of the 851 that were high (10%), 21 (2.5%) elicited a therapeutic response. Of 2089 preoperative laboratory values, 252 (12%) were abnormal, but in only 15 incidences in 9 PTs was any action taken. Three PTs required potassium supplementation and 6 PTs were transfused packed red blood cells before surgery. In the PO period 2603 laboratory values of 6660 obtained (39%) were abnormal. Of these, 735 (28%) were high and 1868 (72%) were low. Twenty of 735 (27%) high values triggered a therapeutic response that most commonly required administration of insulin for elevated serum glucose in 17 of 197 occasions in five diabetic PTs. On three occasions potassium was removed from intravenous fluids. Five of 275 (1.8%) low calcium values were treated in five patients. Potassium was replaced in 17 of 32 occasions in 14 patients where it was low. In this group of PTs, PO serum potassium, hemoglobin levels, and serum glucose in diabetics were the only values important in making therapeutic decisions. If laboratory studies can be streamlined into only those necessary, substantial savings in health care will be seen without sacrificing quality medical care.

Assessment of small intestinal damage in patients treated with pelvic radiotherapy.

Pelvic radiotherapy almost always induces intestinal symptoms. We investigated the radiation-induced damage to the small intestinal mucosa and evaluated its relationship with symptoms, using cellobiose/mannitol permeability test (CE/MA) and plasma postheparin diamine oxidase test (PHD) in 20 patients treated with pelvic radiotherapy. The symptoms developed during radiotherapy were noted. Intestinal permeability significantly (p=0.013) increased from 0.021 +/- 0.026 to 0.047 +/- 0.055 (mean +/- SD) after 15 days of radiotherapy, while it returned to normal values (0.010 0.015) at the end of radiotherapy. PHD values did not change. All patients developed intestinal symptoms. These findings indicate that pelvic radiotherapy induces an early small bowel mucosa damage followed by mucosal adaptation. Acute intestinal symptoms during pelvic radiotherapy may not depend only on small intestinal mucosal damage.

A prospective study of current diagnostic procedures for assessment of hepatic metastases in colorectal cancers.

In a prospective study of 305 patients with colorectal cancers, we assessed the diagnostic value of ultrasonography and laboratory tests. In each case laparotomy was carried out and the presence of liver metastases was established in 47 patients. The results show that the laboratory tests alone are not sufficiently accurate to detect liver metastases. Additional accuracy can be obtained by the combined use of a single liver imaging test (echography) and selected laboratory tests (C.E.A., gamma GT, Alkaline Phosphatase).