Preoperative serum levels of c-erbB-2 do not seem to be useful in management of patients with rectal cancer

Lack of effects of HER-2/neu on prognosis in colorectal cancer: a meta-analysis

BACKGROUND

The prognostic value of human epidermal growth factor receptor-2 (HER-2/neu) for survival of patients with colorectal cancer (CRC) is still ambiguous. We therefore performed a meta-analysis to evaluate its prognostic significance.

MATERIALS AND METHODS

We searched the MEDLINE and EMBASE databases for published literature investigating associations between HER-2/neu status and overall survival of patients with CRC. A meta-analysis was performed using a DerSimonian-Laird model and publication bias was investigated by Begg's and Egger's tests. Subgroup analysis was also conducted according to the study design type, study quality score, cut-off value for HER-2/neu overexpression, publication region, patient number and publication year.

RESULTS

A total of 17 eligible studies involving 2,347 patients were identified for this meta-analysis. The combined hazard ratio (HR) was 1.31 (95% confidence interval (CI): 0.96-1.79), suggesting that HER-2/neu overexpression was not significantly associated with overall survival of patients with CRC. However, subgroup analysis revealed that HER-2/neu overexpression had an unfavorable impact on survival when the analysis was restricted to subgroups of study quality score ≤ 5 (HR=1.56, 95%CI: 1.17-2.10), Asian patients (HR=1.74, 95%CI: 1.22-2.49), patient number ≤ 106 (HR=1.57, 95%CI: 1.01-2.44), publication year before 2003 (HR=1.59, 95%CI: 1.02-2.49), and prospectively designed study (HR=3.62, 95%CI: 1.42-9.24). The effect disappeared in subgroups of study quality scores > 5 (HR=0.69, 95%CI: 0.33-1.44), non Asian patients (HR=1.14, 95%CI: 0.77-1.70), patients' number > 106 (HR=1.07, 95%CI: 0.67-1.72), publication year after 2003 (HR=1.13, 95%CI: 0.76-1.69), and retrospectively designed study (HR=1.22, 95%CI: 0.89-1.67).

CONCLUSIONS

Our meta-analysis suggests that HER-2/neu overexpression might not be a significantly prognostic indicator for patients with CRC. Further studies are required to confirm these results.

Sensitivity estimates of blood-based tests for colorectal cancer detection: impact of overrepresentation of advanced stage disease

A large number of blood-based markers have been proposed for early detection of colorectal cancer (CRC). Their sensitivity for detecting CRC has mostly been evaluated in clinical settings, and found to be higher in more advanced stages compared with earlier stages of the disease. The aim of this study is to estimate the overall sensitivity of blood-based markers expected in screening settings, where the proportion of advanced stages is typically lower than in clinical settings. A systematic literature review was performed on studies evaluating sensitivity and specificity of blood-based markers for early detection of CRC. For each study, overall sensitivity expected in screening settings was estimated by weighting stage-specific sensitivities according to the stage distribution of CRC expected in the screening setting. The latter was derived from 12,605 CRC cases diagnosed in the German screening colonoscopy program during 2003-2007. Overall, 73 studies evaluating 55 blood-based markers were identified. Adjusted sensitivity was lower than reported sensitivity in 120 (90%) evaluations of different markers. Median absolute reduction in sensitivity after adjustment was 9.0% (interquartile range: 4.0-13.0) units, whereas median relative reduction was 19.5% (interquartile range: 11.3-33.3%). Blood-based markers for CRC detection reported from clinical settings showed higher sensitivities than expected in the screening setting in most cases, mainly due to substantially higher proportions of advanced stage cancers. Adjustment of sensitivity to the stage distribution expected in the screening setting is crucial to obtain realistic and comparable estimates of sensitivities.