Oleuropein (OL) and hydroxytyrosol (HT), the main olive oil polyphenols, possess anti-proliferative effects in vitro. Fatty acid synthase, a key anabolic enzyme of biosynthesis of fatty acids, plays an important role in colon carcinoma development. Our aim was to investigate whether gene expression of FAS, as well as its enzymatic activity, is regulated by HT and OL in two human colon cancer cell lines, as HT-29 and SW620. In addition, we investigated the effects of these polyphenols on growth and apoptosis in these cells. FAS gene expression and activity in treated HT-29 and SW620 cells were evaluated by realtime PCR and radiochemical assay, respectively. Cell growth and apoptosis, after polyphenols treatment, were measured by MTT test and flow cytometry, respectively. The inhibition of proliferation, detected after HT treatment, was mediated by an inhibition of FAS expression and its enzymatic activity in SW620 cells, while the anti-proliferative effect in HT-29 cells seems to be independent from FAS. OL exerted an anti-proliferative effect only on SW620 cells with a mechanism which excluded FAS.Olive oil polyphenols used were able to induce apoptosis in both cell lines studied. The increase of apoptosis in these cells was accompanied by the block of cell cycle in the S phase. This study demonstrates that HT and OL may induce anti-proliferative and pro-apoptotic effects only in certain human colorectal cancer cell types. These effects are FAS mediated only in SW620 cells after treatment with HT.

Despite potential inaccuracies in the methodology, the results of the review indicate that anti-oestrogen therapy produces some effect in about one half of patients with DTs. Its indication compared with other treatments is discussed.

Local recurrence continues to be a major problem in rectal cancer. After cancer removal, detection of viable cancer cells could be useful to identify patients at risk for local recurrence. Thus, aim of the study was the detection of residual peritoneal cancer cells with a possible prognostic role for local recurrence. Twenty-nine patients were operated (R0) for low (extraperitoneal) rectal cancer, without neoadjuvant radiochemotherapy. Before and immediately after cancer removal, a peritoneal lavage was done to evaluate by RT-PCR the cytokeratin 20 mRNA on isolated cells and in order to detect cancer cells by the Thin-prep test. After a median follow-up of 39 months, 5 patients died (17%), one for non-cancer-related disease, two (7%) for local recurrence and peritoneal carcinosis, and two for distant metastases. Preoperative cytology with Thin-prep test was positive in 4 patients (14%), while postoperative peritoneal cytology was positive only in 1 patient, different from the previous. No patient developed local or distal recurrence and all were disease-free at the end of the follow-up. RT-PCR analysis was positive on the peritoneal lavage after cancer removal in 11 patients. One died for unrelated cause and no one developed local recurrences. Local recurrence occurred in only 1 of the 2 patients with positive RT-PCR analysis on the first lavage and negative on the second lavage. Our study demonstrates a not important prognostic role of Thin-prep test and RT-PCR of cytokeratin 20 mRNA on the detection of patients at risk for local recurrence after curative resection of rectal cancer.

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