Marco Lorenzi

FOLFOX-4 Stop and Go and Capecitabine Maintenance Chemotherapy in the Treatment of Metastatic Colorectal Cancer

Objective: Patients with metastatic colorectal cancer (MCC) usually receive FOLFOX-4, or other oxaliplatin (L-HOP)-based regimens, until the occurrence of progressive disease, with an increase in the incidence of neurotoxicity which is correlated to the cumulative dose of L-HOP. The aim of this study was to evaluate if FOLFOX-4 stop and go and capecitabine maintenance chemotherapy is associated with a low incidence of severe neurotoxicity in the treatment of MCC patients. Methods: Thirty-three patients were treated with FOLFOX-4 (L-HOP 85 mg/m2 day 1, leucovorin 200 mg/m2, 5-fluorouracil bolus 400 mg/m2 and 22 h 600 mg/m2 days 1 and 2, every 2 weeks). Patients who achieved objective response (OR) or stable disease (SD) then received oral capecitabine 2,500 mg/m2 days 1–14 every 3 weeks; L-HOP was reintroduced as soon as progression occurred. Results: Twenty-eight of the 29 patients who achieved OR or SD then received capecitabine. FOLFOX-4 was reintroduced in 18 patients (56.2%). The median response duration (RD) was 9.2 months and median progression-free survival (PFS) was 8.6 months. Twenty-eight patients (87.5%) had peripheral neuropathy during treatment, but grade 3 neurotoxicity was observed in only 1 patient (3.1%). Conclusions: FOLFOX-4 stop and go and capecitabine maintenance chemotherapy was associated with a very low incidence of grade 3 neurotoxicity. Although the number of patients enrolled was far too low for a definite conclusion, RD and PFS were comparable to those usually reported in the treatment of MCC patients.

Immunohistochemical expression of p53 and Ki67 in colorectal adenomas and prediction of malignancy and development of new polyps.

The aim of this study was to investigate the immunohistochemical expression of p53 and Ki67 in colorectal adenomas in order to clarify their significance as indicators of malignancy and development of new polyps. Seventy-eight polyps were removed from 51 patients and examined. Twenty-nine patients (56.9%) had adenomas with low-grade atypia (13 of them developed new polyps at 3-year follow-up) and 22 (43.1%) had adenomas with high-grade atypia (6 of them developed new polyps at 3-year follow-up). We tested the association between p53 and Ki67 expression and various clinicopathological variables, and regression analysis was performed to identify the risk factors for malignancy and development of new adenomas. A significant correlation between the grade of atypia and p53 immunoreactivity was observed. Ki67 expression was not related to atypia and no correlation was found between p53 and Ki67 immunoreactivity. Regression analysis showed that size (p=0.0002) and p53 staining (p=0.0111) were the selected factors related to malignant transformation, whereas the number of synchronous primary polyps emerged as the only predictive factor of development of new adenomas, although without statistical significance. The expression of biological markers may be in future added to the currently examined features of polyps; however, further studies are needed to better define their predictive value.

Continuous oral capecitabine at fixed dose in patients older than 75 years with metastatic colorectal and gastric cancer: a study of the Multidisciplinary Oncology Group on Gastrointestinal Tumors

The aim of this study was to investigate the safety profile of continuous oral capecitabine at fixed dose in patients older than 75 years, having metastatic colorectal and gastric cancer. Capecitabine was administered at a fixed dose of 2000 mg daily without interruptions. Thirty-four patients were considered evaluable for toxicity and efficacy. The median age was 81 years (range 76–85). The median duration of treatment was 113 days (range 24–238 days). No grade 4 toxicity was observed. One patient had grade 3 nausea and vomiting, and one had grade 3 diarrhea. Partial responses were observed in six patients with colorectal cancer, and in one patient with gastric cancer. This study suggests that continuous oral capecitabine at a fixed daily dose of 2000 mg is well tolerated, and that it allows for the simplification and ease of dosing in elderly patients with metastatic colorectal and gastric cancer.

Serum ferritin in colorectal cancer patients and its prognostic evaluation.

The aim of this study was to investigate the relationship between preoperative serum ferritin levels, clinico-pathological parameters and survival analysis of patients with colorectal cancer. Ninety-four patients (57 males) with a mean age of 65 years (39-87 years) underwent 63 curative and 31 palliative operations. Follow-up was at least 5 years. Patients were categorized with normal (30-215 ng/mL in men and 11-148 ng/mL in women), low, or high serum ferritin levels. Prognostic evaluation was undertaken with stratified survival analysis and Coxs regression model. Twenty-nine of the patients (30.9%) had raised ferritin levels and 14 (14.9%) had low values. Comparisons of the survival curves showed significant differences in stage C disease; specifically, patients with either low or high ferritin levels had a shorter survival than patients with normal levels. Patients who underwent palliative surgery and had high ferritin serum values also had a shorter survival. In multivariate analysis, the variables with a negative effect on survival were stage, serum ferritin levels and age. Our data suggest that patients with advanced colorectal cancer having normal preoperative serum ferritin levels may have a better prognosis, although the prognostic value related to this association requires further investigation.

Behavior of l-threonine-degrading enzymes during liver regeneration

We examined the effects of a two-thirds hepatectomy in the adult rat on the activities of the three L-threonine-degrading enzymes, L-threonine dehydratase, L-threonine aldolase and L-threonine dehydrogenase. Noticeable variations were observed which did not occur in either sham-operated or turpentine-treated rats and were not linked to food intake. They were considered specific to the regenerating liver. When the reactions were followed in vitro, L-threonine deaminase and L-threonine aldolase were significantly lower for the first 12-24 h: L-threonine dehydrogenase decreased only after 48 h. These results are linked to a decrease in the enzyme concentration in the tissue. L-Serine and L-threonine liver concentrations increased 2-3-fold during the same periods. When the activities were evaluated in vivo, the levels of the first two enzymes remained constant for 24 h, but increased after 48 h; L-threonine dehydrogenase increased between 12 and 48 h. The in vivo activity of the enzymes was reflected by total L-threonine degradation, which had a single sharp peak at 48 h. The asynchronous variations in enzyme activity are related to the differences in protein metabolism which occur in the regenerating liver, and are the consequence of a new transient differential control. The changes observed are significant in liver regeneration; they regulate the consumption and the serum and liver levels of L-serine and L-threonine, setting them aside for protein synthesis. They minutely control the flux of amino acids toward gluconeogenesis, since, during the first 48 h after partial hepatectomy, the production of glucose is ensured principally by lactate; the contribution of L-threonine seems to be more significant only at 48 h. These findings are useful in the study of the regulation of the enzymes involved in amino acid metabolism during liver regeneration.

Treatment of experimental esophagogastric myotomy with bone marrow mesenchymal stem cells in a rat model

Over the last 15 years, many studies demonstrated the myogenic regenerative potential of bone marrow mesenchymal stem cells (BM‐MSC), making them an attractive tool for the regeneration of damaged tissues. In this study, we have developed an animal model of esophagogastric myotomy (MY) aimed at determining the role of autologous MSC in the regeneration of the lower esophageal sphincter (LES) after surgery.

Treatment of lower oesophageal sphincter damage with bone marrow derived mesenchymal stem cells

Background. The incompetence of lower esophageal sphincter (LES) with consequent exposition of the esophageal mucosa to gastric acid leads to gastroesophageal reflux disease. The aim of this study was to evaluate whether intralesional injections of Bone Marrow Mesenchymal Stem Cells (BM-MSC), which proved useful in the treatment of urinary (1) and anal (2) incontinence, could also help muscle regeneration at the site of surgical myotomy of rat LES. Methods. 24 inbred Wistar Furth rats were divided into three groups: group A underwent a sham operation followed by saline injection; group B LES myotomy plus saline injection; group C LES myotomy followed by an intra-sphincteric injection of culture-expanded syngeneic BM-MSC. At day 30, histological and morphometric analysis were performed on metacrylate embedded samples. GFP positive MSC isolated from transgenic rats were moreover used to track the cells in the injured area in cryostat sections at days 7, 14 and 30 after the lesion. Cryostat sections were also used for immunohistochemical detection of striated and smooth muscular markers (a actinin, a smooth muscle actin, calponin). Results. At day 30 of surgery, the muscle area fraction (MAF) at the site of LES myotomy was significantly higher in group C compared to group B animals (p<0.05) and contained a high number of small irregularly arranged smooth muscle cells, sometimes grouped in clusters. GFP positive cells could be tracked at the periphery of the lesion at day 7 and also inside the lesion at day 14 of surgery when the damaged area, as evidenced by specific antibodies, was still devoid of smooth or striated muscle cells. At day 30, the lesion was recognizable only as a disorganized area at the periphery of the muscular layer. At this time clusters of GFP positive cells, unstained by muscular specific antibodies, could still be detected at the periphery and sometimes also in the center of the muscular layer. Conclusions. BM-derived MSC, improving muscle regeneration of surgically myotomy LES in the rat, may represent a valuable tool in the treatment of LES injury. 1) Y.Kinebuchi et al. Int.J.Urol. 2010, 17:359-68 2) B.Lorenzi et al.Dis Colon Rectum 2008, 51:411-20.