Survival in stage II/III colorectal cancer is independently predicted by chromosomal and microsatellite instability, but not by specific driver mutations.

OBJECTIVES: Microsatellite instability (MSI) is an established marker of good prognosis in colorectal cancer (CRC). Chromosomal instability (CIN) is strongly negatively associated with MSI and has been shown to be a marker of poor prognosis in a small number of studies. However, a substantial group of "double-negative" (MSI-/CIN-) CRCs exists. The prognosis of these patients is unclear. Furthermore, MSI and CIN are each associated with specific molecular changes, such as mutations in KRAS and BRAF, that have been associated with prognosis. It is not known which of MSI, CIN, and the specific gene mutations are primary predictors of survival. METHODS: We evaluated the prognostic value (disease-free survival, DFS) of CIN, MSI, mutations in KRAS, NRAS, BRAF, PIK3CA, FBXW7, and TP53, and chromosome 18q loss-of-heterozygosity (LOH) in 822 patients from the VICTOR trial of stage II/III CRC. We followed up promising associations in an Australian community-based cohort (N=375). RESULTS: In the VICTOR patients, no specific mutation was associated with DFS, but individually MSI and CIN showed significant associations after adjusting for stage, age, gender, tumor location, and therapy. A combined analysis of the VICTOR and community-based cohorts showed that MSI and CIN were independent predictors of DFS (for MSI, hazard ratio (HR)=0.58, 95% confidence interval (CI) 0.36-0.93, and P=0.021; for CIN, HR=1.54, 95% CI 1.14-2.08, and P=0.005), and joint CIN/MSI testing significantly improved the prognostic prediction of MSI alone (P=0.028). Higher levels of CIN were monotonically associated with progressively poorer DFS, and a semi-quantitative measure of CIN was a better predictor of outcome than a simple CIN+/- variable. All measures of CIN predicted DFS better than the recently described Watanabe LOH ratio. CONCLUSIONS: MSI and CIN are independent predictors of DFS for stage II/III CRC. Prognostic molecular tests for CRC relapse should currently use MSI and a quantitative measure of CIN rather than specific gene mutations.

Use of lipoteichoic acid-T for pleurodesis in malignant pleural effusion: a phase I toxicity and dose-escalation study.

BACKGROUND: Bacterial infection of the pleural space often causes adherence of the pleural membranes by fibrous tissue, probably mediated by inflammation initiated by bacterial cell-wall motifs, including lipoteichoic acid-T (LTA-T). We postulated that therapeutically administered LTA-T might produce a similar effect, achieving control of malignant pleural effusion (pleurodesis). METHODS: Patients with histocytologically proven symptomatic malignant pleural effusions were included in this phase I toxicity and dose-escalation study, An indwelling pleural catheter was placed in the pleural effusion to drain the fluid fully. A control dose of intrapleural saline was administered after complete drainage (day 1) and pleural-fluid production was recorded for 7 days. On day 7 a single dose of intrapleural LTA-T (increasing in each patient) was administered and pleural-fluid production was monitored for a further 7 days. Long-term fluid control was recorded. This study is registered as an International Standard Randomised Controlled Trial, ISRCTN44367564. FINDINGS: Between November, 2004, and November, 2005, 14 patients were enrolled on the trial at the Oxford Centre for Respiratory Medicine (Oxford, UK). 13 of 14 patients received escalated doses of LTA-T. A dose-limiting toxic effect (ie, systemic inflammation) occurred at 3000 microg, and a therapeutic dose of 750-1500 microg was established. Toxic effects were mild and had no consistent pattern at the therapeutic dose. Pleural-fluid production decreased significantly after a dose of at least 750 microg LTA-T, compared with saline control (mean fluid production after saline control 1244 mL [SD 933], mean fluid production after LTA-T 394 mL [SD 375], mean difference -850 mL [SD 699], p=0.028), and six of seven (86%) patients achieved pleural-fluid control at 1 month with no further intervention. INTERPRETATION: The toxic effects of intrapleural LTA-T seem to be mild and favourable when compared with the toxicity profiles of standard pleurodesis agents. There is early evidence of LTA-T-induced pleurodesis efficacy, suggesting that this might be a viable therapeutic strategy for the control of malignant pleural effusion.