Purpose: The clinical relevance of CA 19-9 as surrogate biomarker in advanced pancreatic cancer is a matter of debate. Experimental Design: This retrospective multicenter study included patients with histologically confirmed advanced pancreatic cancer treated with first-line therapy. Analysis of CA 19-9 was done using the Elecsys assay (Roche Diagnostics). For an analysis of CA 19-9 kinetics, at least three measurements during first-line chemotherapy had to be available. The effect of pretreatment CA 19-9 levels on time-to-progression (TTP) and overall survival (OS) was modeled by Cox proportional hazards regression. The effect of CA 19-9 kinetics was also modeled by Cox proportional hazards regression where CA 19-9 was treated as a time-varying covariate. Results: One hundred and fifteen patients from five German centers were included; 73% of them were treated within prospective clinical trials. Median TTP was 4.4 months and median OS was 9.4 months; univariate analysis indicated that pretreatment CA 19-9 [as continuous variable, log (CA 19-9)] was significantly associated with TTP [hazard ratio (HR), 1.24; P < 0.001] and OS (HR, 1.16; P = 0.002). These associations remained significant within multivariate analysis. For CA 19-9 kinetics during chemotherapy, data from 69 patients (TTP) and 84 patients (OS) were available, respectively; log (CA 19-9) kinetics after start of treatment were found to be a significant predictor for TTP in univariate (HR, 1.48; P < 0.001) and multivariate (HR, 1.45; P < 0.001) analyses, and also for OS (univariate: HR, 1.34; P < 0.001; multivariate: HR, 1.38; P < 0.001). Conclusion: Pretreatment CA 19-9 and CA 19-9 kinetics may serve as a useful serum biomarker in advanced pancreatic cancer. Clin Cancer Res; 16(3); 986–94

Mutations in the KRAS gene can be detected in about 70-90% of pancreatic cancer (PC) cases. Whether these mutations have a prognostic or predictive value remains elusive. Furthermore, the clinical relevance of the extended RAS (KRAS+NRAS) mutational status is unclear in PC. We prospectively defined a PC patient population who received erlotinib-free chemotherapy regimens. A statistically significant difference between KRAS wild-type and KRAS mutated tumours in at least 160 patients in this population would support the assumption of a rather prognostic role of KRAS. One hundred and seventy-eight tumour samples were collected from prospective clinical studies and successfully analysed for the extended RAS status: 37 tumours were KRAS wild-type (21%), whereas 141 (79%) carried a KRAS mutation; 132 of these mutations were found in KRAS exon 2 (74%), whereas only 9 mutations (5%) were detected in KRAS exon 3. Within KRAS exon 4 and NRAS exons 2-4, no mutations were apparent. There was no significant difference in overall survival for KRAS wild-type vs mutant patients (9.9 vs 8.3 months, P=0.70). Together with the results of the AIO-PK-0104-trial, the present analysis supports the notion that KRAS mutation status is rather predictive than prognostic in advanced PC.

The role of pERK, pAKT and p53 as biomarkers in patients with advanced pancreatic cancer has not yet been defined. Within the phase III study AIO-PK0104 281 patients with advanced pancreatic cancer received an erlotinib-based 1st-line regimen. Archival tissue from 153 patients was available for central immunohistochemistry staining for pERK, pAKT and p53. Within a subgroup analysis, biomarker data were correlated with efficacy endpoints and skin rash using a Cox regression model. Fifty-five out of 153 patients were classified as pERKlow and 98 patients as pERKhigh; median overall survival (OS) was 6.2 months and 5.7 months, respectively (HR 1.29, p = 0.16). When analysing pERK as continuous variable, the pERK score was significantly associated with OS (HR 1.06, 95% CI 1.0-1.12, p = 0.05). Twenty-one of 35 patients were pAKTlow and 14/35 pAKThigh with a corresponding median OS of 6.4 months and 6.8 months, respectively (HR 1.03, p = 0.93). Four out of 50 patients had a complete loss of p53 expression, 20 patients a regular expression and 26 patients had tumors with p53 overexpression. The p53 status had no impact on OS (p = 0.91); however, a significant improvement in progression-free survival (PFS) (6.0 vs 1.8 months, HR 0.24, p = 0.02) and a higher rate of skin rash (84% vs 25%, p = 0.02) was observed for patients with a regular p53 expression compared to patients with a complete loss of p53. pERK expression may have an impact on OS in erlotinib-treated patients with advanced pancreatic cancer; p53 should be further investigated for its potential role as a predictive marker for PFS and skin rash. NCT00440167 (registration date: February 22, 2007).

The role of the tumor suppressor mothers against decapentaplegic homolog 4 (SMAD4) has not yet been defined in patients (pts) with advanced pancreatic cancer (aPC). This translational research study was designed to evaluate the impact of tumoral SMAD4 loss on clinicopathological parameters and outcome in PC patients receiving palliative chemotherapy. Using immunohistochemistry, we examined SMAD4 expression in tumor tissue of 143 aPC pts treated within completed prospective clinical and biomarker trials. In uni- and multivariate analyses, SMAD4 expression status was correlated to clinicopathological patient characteristics and outcome. At chemotherapy initiation, 128 pts had metastatic PC; most pts (n = 99) received a gemcitabine-based regimen. SMAD4 loss was detected in 92 pts (64%); patient characteristics such as gender, age, tumor grading, disease stage or number of metastatic sites had no significant impact on tumoral SMAD4 status. In univariate analyses, SMAD4 loss had no impact on overall survival (hazard ratio (HR) 1.008, p = 0.656); however, we observed a prolonged progression-free survival (HR 1.565, p = 0.038) in pts with tumoral SMAD4 loss. This finding was confirmed in multivariate analyses (HR 1.790, p = 0.040), but only for gemcitabine-treated pts. In contrast to previous studies in resectable PC, loss of SMAD4 expression was not associated with a negative outcome in patients with advanced PC receiving systemic chemotherapy.