BACKGROUND:Clinical trials in metastatic colorectal cancer (mCRC) are usually conducted irrespectively of sex. However, differences relating to safety and efficacy in the treatment of mCRC between male and female patients are of growing interest. METHODS:The randomized FIRE-3 study compared first-line treatment with folinic acid, 5-fluorouracil and irinotecan (FOLFIRI) plus cetuximab to FOLFIRI plus bevacizumab in patients with RAS wildtype (RAS WT) mCRC. The present analysis focusses on the impact of sex and primary tumor (PT) sidedness on outcome parameters. RESULTS:Of 352 patients with RAS WT tumors, 249 (71 %) were male and 103 (29 %) female. In male patients with left-sided RAS/BRAF WT tumors, a significant benefit from cetuximab was noted with regard to ORR (OR 1.15; P = 0.035) and OS (0.66; P = 0.010), while in right-sided patients cetuximab improved ORR (OR 2.92) and had no significant effect on PFS or OS. In female patients with left-sided, RAS/BRAF WT PT, a comparable effect of cetuximab versus bevacizumab was observed with regard to ORR (OR 1.05; P > 0.999), while a numerical OS benefit was noted in the cetuximab-arm (HR 0.78; P = 0.385). By contrast, in female patients with right-sided PT, a clearly detrimental effect of cetuximab-based therapy was observed for ORR (OR 0.44; P = 0.617), PFS (HR 4.95; P = 0.005), and OS (HR 2.58; P = 0.080). In the bevacizumab arm, neutropenia grade ≥ 3 was more frequent in female versus male patients (30.6 % versus 18.3 %; P = 0.063). Otherwise, there was no significant difference of grade ≥ 3 adverse events between male and female patients. CONCLUSIONS:The exploratory analysis of FIRE-3 suggests that the efficacy of cetuximab combined with FOLFIRI in RAS wild-type mCRC is related to sex and primary tumor sidedness. The results support the inclusion of patient sex into the design of future trials.

13 Background: Optimal patient selection for first-line treatment targeting epithelial growth factor receptor (EGFR) in RAS-WT mCRC is based on primary tumor sidedness (PTS) with anti-EGFR being the preferred option for patients with left-sided mCRC (LC). Right-sided mCRCs (RC) are preferentially treated in combination with bevacizumab targeting vascular endothelial growth factor (VEGF). Here, improvement in patient selection was evaluated by combining clinical biomarkers beyond PTS using the randomized phase III trial FIRE-3. Methods: FIRE-3 evaluated first-line FOLFIRI (folinic acid, fluorouracil and irinotecan) plus cetuximab (FOLFIRI/Cet) versus FOLFIRI plus bevacizumab (FOLFIRI/Bev) in patients with RAS-WT mCRC. Besides PTS, further clinical biomarkers were evaluated in pairwise combinations using Cox regression models and model-based recursive partitioning with Weibull models to predict treatment benefit of either treatment arm regarding overall survival (OS): age, sex, liver-limited disease status (LLD) and baseline carcinoembryonic antigen serum level (CEA). The resulting P-values of second-order interactions were adjusted using Holm-Bonferroni correction. The model with the best test statistics and P-value was chosen for further evaluations. Results: In 400 patients with RAS-WT mCRC, a model combining PTS and LLD status best predicted treatment outcome of either treatment arm (c-index = 0.603, p=0.005). Here, a significant survival benefit of FOLFIRI/Cet over FOLFIRI/Bev was evident in patients with LC/non-LLD (HR 0.62, p=0.02) compared to LC/LLD (HR 0.83, p=0.40). In patients with RC, FOLFIRI/Bev was significantly associated with increased OS compared to FOLFIRI/Cet when patients suffered from non-LLD (HR 2.09, p=0.010). However, patients with RC/LLD rather had a benefit from FOLFIRI/Cet compared to FOLFIRI/Bev (HR 0.59, p=0.218). Conclusions: Combining clinical biomarkers PTS and LLD status might improve optimal patient selection for targeted first-line treatment in RAS-WT mCRC. Validation in further data sets is warranted. Clinical trial information: NCT00433927 .

3529 Background: CMS were associated with prognostic relevance in RAS WT mCRC, while their role as predictive biomarker is debatable. We aimed to assess the predictive impact of CMS on treatment with anti-EGFR vs. anti-VEGF antibodies vs. cytotoxic treatment alone in a pooled analysis. Methods: Available CMS data (called by predictedCMS method) of the randomized controlled trials FIRE-1 (FUFIRI vs. mIrOx); FIRE-3 (FOLFIRI+ cetuximab vs. bevacizumab), XELAVIRI (sequential vs. initially combined FOLFIRI+bevacizumab) and PanaMa (FOLFOX+panitumumab followed by FU/FA +/- panitumumab) of RAS WT mCRC were included. Non-evaluable CMS were excluded. Kaplan-Meier estimated overall survival (OS) and progression-free survival (PFS). Uni- and multivariate Cox regression analysis (including all baseline characteristics) was used to calculate hazard ratio (HR) and 95% confidence interval (95% CI). Results: 1147 tumors had available CMS data and 746 (65.0%) were RAS wild-type (WT): CMS1, n=89; CMS2, n=346; CMS3, n=71; CMS4, n=240. CMS were significant prognostic biomarkers in terms of PFS (median months, CMS1, 6.7; CMS2, 11.1; CMS3, 8.1; CMS4, 10.0, P<0.001) and OS (median months: CMS1, 14.8; CMS2, 28.7; CMS3, 19.5; CMS4, 26.5; P<0.001). CMS remained significant in a multivariate backward elimination Cox regression analysis including all baseline characteristic variables and BRAF status with regard to PFS ( P=0.03) and OS ( P=0.04) Interaction of CMS and treatment was significant regarding OS ( P<0.001) and PFS ( P=0.001). The longest OS was observed using anti-VEGF antibodies in CMS1 and anti-EGFR antibodies in CMS2 or CMS4 RAS WT tumors (Table). Conclusions: CMS were confirmed as prognostic biomarkers and might contain predictive information for the choice of anti-EGFR or anti-VEGF antibodies in RAS WT mCRC. Prospective validation remains mandatory. [Table: see text]

3550 Background: Doublet chemotherapy plus bevacizumab is a well-established standard of care in the first-line treatment of RAS-mutant (RASmut) metastatic colorectal cancer (mCRC). The FIRE-3 trial was the first randomized study to compare FOLFIRI plus cetuximab to FOLFIRI plus bevacizumab in mCRC. Since this trial initially included patients irrespective of RAS mutation status, the present analysis performs an updated evaluation of therapeutic efficacy of targeted therapy with bevacizumab versus cetuximab in RASmut mCRC. Methods: FIRE-3 trial included 752 patients. Initially, pyrosequencing (PSeq) was used to identify RAS mutations. In a subsequent investigation next-generation sequencing (NGS) was applied in 373 available tumors. A 5% mutant allele cutoff was used for both PSeq and NGS both of which were done centrally. Results: Of the 224 RASmut and BRAF wild-type patients, 187 were identified by polymerase chain reaction (PCR) and PSeq, 122 by NGS. 86 tumors were PCR positive and NGS positive (PCR+/NGS+), 36 tumors PCR negative and NGS positive (PCR-/NGS+). In the overall RASmut cohort of 224 patients, no overall survival (OS) benefit was observed when cetuximab was compared to bevacizumab (20.3 months vs 21.1 months; HR 1.028; 95% CI, 0.547-1.583; P=.842). This effect was observed independent of sidedness of primary tumors (PT) for left-sided (21.5 months vs 22.1 months; HR 1.054; 95% CI, 0.763-1.456) and right-sided PT (19.2 months vs 19.5 months; HR 0.931; 95% CI, 0.547-1.583). Conclusions: While cetuximab notably is not effective in RASmut mCRC, this randomized comparison does not provide an indication for superior efficacy of bevacizumab in the first-line treatment of this patient group. Trial identification number: NCT00433927 [clinicaltrials.gov]

Summary Background The evidence on the efficacy of anticancer therapy is limited in older patients with metastatic colorectal cancer (mCRC). This retrospective analysis of phase III FIRE-3 trial assesses the efficacy of FOLFIRI plus either cetuximab or bevacizumab according to the patients’ age and sidedness of primary tumour. Methods The study endpoints overall response rate (ORR), progression-free survival (PFS) and overall survival (OS) were compared between younger (<65 years) and older (≥65 years) patients, followed by stratification according to primary tumour sidedness. ORR was compared using Fisher´s exact test, OS and PFS were estimated by the Kaplan–Meier method and compared using the log-rank test. Univariate Cox regression analyses assessed hazard ratios and 95% confidence intervals for OS and PFS. Results Overall, older patients with RAS WT tumours had a significantly shorter OS when compared to younger patients (25.9 months vs 29.3 months, HR 1.29; P = 0.02). Also the proportion of right-sided tumours was significantly greater in older patients (27.1% vs 17.9%; P = 0.029). Secondary resection rates were numerically higher in younger patients (25.4% vs. 17.6%, P = 0.068) than in older patients. This was primarily seen in the Cetuximab arm, where older patients underwent less likely resection (13.1% vs. 26%; P = 0.02). Older patients with left-sided tumours showed only a trend towards greater efficacy of cetuximab (HR 0.86; P = 0.38). In patients with right-sided primary tumours, older patients did not appear to benefit from cetuximab in contrast to younger patients (≥65 years: 16.6 months vs 23.6 months, HR 1.1; P = 0.87; <65 years: 21.9 months vs 16.4 months HR 1.5; P = 0.31). Conclusions In FIRE-3, OS was generally shorter in older patients in comparison to younger patients. This could be explained by the overrepresentation of right-sided tumours and a lower secondary resection rate in older patients. The efficacy of targeted therapy was dependent on tumour sidedness in older patients with RAS WT mCRC. Clinical trial FIRE-3 (NCT00433927).

OBJECTIVES:Early tumor shrinkage (ETS) quantifies the objective response at the first assessment during systemic treatment. In metastatic colorectal cancer (mCRC), ETS gains relevance as an early available surrogate for patient survival. The aim of this study was to increase the predictive accuracy of ETS by using semi-automated volumetry instead of standard diametric measurements.METHODS:Diametric and volumetric ETS were retrospectively calculated in 253 mCRC patients who received 5-fluorouracil, leucovorin, and irinotecan (FOLFIRI) combined with either cetuximab or bevacizumab. The association of diametric and volumetric ETS with overall survival (OS) and progression-free survival (PFS) was compared.RESULTS:Continuous diametric and volumetric ETS predicted survival similarly regarding concordance indices (p > .05). In receiver operating characteristics, a volumetric threshold of 45% optimally identified short-term survivors. For patients with volumetric ETS ≥ 45% (vs < 45%), median OS was longer (32.5 vs 19.0 months, p < .001) and the risk of death reduced for the first and second year (hazard ratio [HR] = 0.25, p < .001, and HR = 0.39, p < .001). Patients with ETS ≥ 45% had a reduced risk of progressive disease only for the first 6 months (HR = 0.26, p < .001). These survival times and risks were comparable to those of diametric ETS ≥ 20% (vs < 20%).CONCLUSIONS:The accuracy of ETS in predicting survival was not increased by volumetric instead of diametric measurements. Continuous diametric and volumetric ETS similarly predicted survival, regardless of whether patients received cetuximab or bevacizumab. A volumetric ETS threshold of 45% and a diametric ETS threshold of 20% equally identified short-term survivors.KEY POINTS:• ETS based on volumetric measurements did not predict survival more accurately than ETS based on standard diametric measurements. • Continuous diametric and volumetric ETS predicted survival similarly in patients receiving FOLFIRI with cetuximab or bevacizumab. • A volumetric ETS threshold of 45% and a diametric ETS threshold of 20% equally identified short-term survivors.

The authors regret there were mistakes in some graphics for the subpopulation with BRAF mutated tumors in above publication. These mistakes were found in Figure 2C (small BRAF graphic), Figure 2D (only BRAF) and Figure 4 (BRAF V600E MUT and BRAF non-V600E MUT subgraphic). To support these corrections, the Authors also note that the following section of text require some updates: In Section 3.8. Association of KRAS, BRAF and SMAD4 SNVs, TMB-H and MSI-H with CMSs, page 254 of the printed paperCombined NGS and CMS data were available for 349 of 373 patients (93.6%). KRAS- and BRAF V600E-MUT tumours were mainly classified as CMS2 and 4. CMS4 was detected in 6 of 11 (54.5%) BRAF non-V600E-MUT tumours. Eight, 10 and 9 SMAD4-MUT tumours were classified as CMS1, CMS2 and CMS4, respectively, and CMS3 was detected once. Eight of 10 MSI-H tumours (80.0%) were associated with CMS1, and one tumour was associated with CMS3 and CMS4. TMB-H tumours were enriched by CMS1, followed by CMS2, CMS4 and CMS3 (Fig. 4). Fig. 2 Should be corrected toCombined NGS and CMS data were available for 349 of 373 patients (93.6%). KRAS-MUT tumours were mainly classified as CMS2 and 4, and BRAF V600E-MUT CMS1 (75.0%), respectively. CMS2 was detected in 4 of 11 (36.3%) BRAF non- V600E-MUT tumours. Eight, 10 and 9 SMAD4-MUT tumours were classified as CMS1, CMS2 and CMS4, respectively, and CMS3 was detected once. Eight of 10 MSI-H tumours (80.0%) were associated with CMS1, and one tumour was associated with CMS3 and CMS4. TMB-H tumours were enriched by CMS1, followed by CMS2, CMS4 and CMS3 (Fig. 4). Furthermore, in the Discussion section, page 256, the following textEventually, we investigated the enrichment of relevant alterations in the previously reported mRNA expression-based CMSs (CMS1: immune, CMS2: canonical; CMS3: metabolic; CMS4: mesenchymal) [7]. While we confirmed enrichment of MSI-H, TMB-H and BRAF V600E-MUT tumours in CMS1 [7e9], BRAF non-V600E-MUT tumours were associated with CMS4, indicating again the possibility of a distinct subgroup. Should be corrected toEventually, we investigated the enrichment of relevant alterations in the previously reported mRNA expression-based CMSs (CMS1: immune, CMS2: canonical; CMS3: metabolic; CMS4: mesenchymal) [7]. While we confirmed enrichment of MSI-H, TMB-H and BRAF V600E-MUT tumours in CMS1 [7e9], BRAF non-V600E-MUT tumours were associated with CMS2, indicating again the possibility of a distinct subgroup. The outcome results and survival curves are not affected. The corrected figures are given here. Fig. 4 The authors would like to apologise for any inconvenience caused. Single-nucleotide variants, tumour mutational burden and microsatellite instability in patients with metastatic colorectal cancer: Next-generation sequencing results of the FIRE-3 trialEuropean Journal of CancerVol. 137PreviewMolecular biomarkers and primary tumour sidedness guide treatment decisions in metastatic colorectal cancer. Comprehensive molecular profiling aims to identify targetable alterations and measure tumour mutational burden (TMB) to enable precision oncology. Full-Text PDF

Background The multicenter, open-label, randomized, phase III EPIC study (EMR 062202-025) investigated cetuximab plus irinotecan versus irinotecan in patients with epidermal growth factor receptor-detectable metastatic colorectal cancer (mCRC) that progressed on first-line fluoropyrimidine- and oxaliplatin-based chemotherapy; we report the outcomes of patients with RAS-wild-type (wt) disease. Materials and Methods Available DNA samples from RAS-unselected patients (n = 1,164 of 1,298 [89.7%]) were reanalyzed for RAS mutations using beads, emulsion, amplification, and magnetics. Baseline characteristics, efficacy, safety, and poststudy therapy were assessed. RAS-wt status was defined as a mutated RAS allele frequency of <= 5%, with all relevant alleles being analyzable. Results Baseline characteristics were comparable between the groups (n = 452 patients with RAS-wt mCRC; cetuximab plus irinotecan n = 231, irinotecan n = 221) and between the RAS-wt and RAS-unselected populations. In the cetuximab plus irinotecan versus irinotecan arms, median overall survival was 12.3 versus 12.0 months, median progression-free survival (PFS) was 5.4 versus 2.6 months, and objective response rate (ORR) was 29.4% versus 5.0%, respectively. Quality of life (QoL) was improved in the cetuximab plus irinotecan arm. Serious adverse events occurred in 45.4% (cetuximab plus irinotecan) and 42.4% (irinotecan) of patients. In total, 47.1% of patients in the irinotecan arm received subsequent cetuximab therapy. Conclusion PFS, ORR, and QoL were improved with cetuximab plus irinotecan as a second-line treatment in patients with RAS-wt mCRC, confirming that cetuximab-based therapy is suitable in this population. Almost half of patients in the irinotecan arm received poststudy cetuximab, masking a potential overall survival benefit of cetuximab addition. Implications for Practice Cetuximab is approved for the treatment of RAS-wild-type metastatic colorectal cancer (mCRC). In this retrospective analysis of the phase III EPIC study (cetuximab plus irinotecan vs. irinotecan alone as second-line treatment in patients with RAS-unselected mCRC), the subgroup of patients with RAS-wild-type mCRC who received cetuximab plus irinotecan had improved progression-free survival, objective response rate, and quality of life compared with the RAS-unselected population. These findings suggest that cetuximab-based therapy is a suitable second-line treatment for patients with RAS-wild-type mCRC.

Body weight loss is frequently regarded as negatively related to outcomes in patients with malignancies. This retrospective analysis of the FIRE‐3 study evaluated the evolution of body weight in patients with metastatic colorectal cancer (mCRC). FIRE‐3 evaluated first‐line FOLFIRI (folinic acid, fluorouracil and irinotecan) plus cetuximab or bevacizumab in mCRC patients with RAS ‐WT tumors (ie, wild‐type in KRAS and NRAS exons 2‐4). The prognostic and predictive relevance of early weight loss (EWL) regarding patient outcomes and treatment side effects were evaluated. Retrospective data on body weight during first 6 months of treatment were evaluated (N = 326). To correlate with efficacy endpoints and treatment side effects, patients were grouped according to clinically significant EWL ≥5% and <5% at Month 3. Age constituted the only significant predictor of EWL following a linear relationship with the corresponding log odds ratio ( P = .016). EWL was significantly associated with the incident frequencies of diarrhea, edema, fatigue, nausea and vomiting. Further, a multivariate analysis revealed EWL to be an independent negative prognostic factor for overall survival (32.4 vs 21.1 months; hazard ratio [HR]: 1.64; 95% confidence interval [CI] = 1.13‐2.38; P = .0098) and progression‐free survival (11.8 vs 9.0 months; HR: 1.72; 95% CI = 1.18‐2.5; P = .0048). In conclusion, EWL during systemic treatment against mCRC is significantly associated with patient age. Patients exhibiting EWL had worse survival and higher frequencies of adverse events. Early preventative measures targeted at weight maintenance should be evaluated, especially in elderly patients being at highest risk of EWL.

4070 Background: The FIRE-3 study (AIO KRK-0306) was designed as a randomized multicenter trial to compare the efficacy of FOLFIRI plus cetuximab (cet) to FOLFIRI plus bevacizumab (bev) as first-line treatment in KRAS WT mCRC patients. FOLFIRI plus cet as first-line treatment of KRAS WT mCRC patients resulted in comparable overall response rates (ORR) and progression free survival (PFS) when compared to FOLFIRI plus bev. Overall survival (OS) was significantly longer in the FOLFIRI plus cet arm. Methods: In the present analysis of the FIRE-3 trial we explored the impact of primary tumor resection on outcome in relation to anti-EGFR vs. anti-VEGF treatment. Furthermore, we investigated the prognostic value of synchronous versus metachronous metastases. Results: In patients with synchronous disease no significant difference in OS was detected when comparing resected (n=339) vs. non-resected (n=97) patients (p-value: 0.29, HR: 1.17, 95%-CI: 0.88 – 1.55). In the cetuximab arm, resection (n=167) showed no significant benefit in OS when compared to non-resection (n=52) (p-value: 0.51, HR: 1.15, 95%-CI: 0.77 – 1.71). Treated with bevacizumab, similar results were present, when comparing resection (n=172) vs. non-resection (n=45); (p-value: 0.29, HR: 1.25, 95%-CI: 0.83 – 1.9). A strong trend was seen when comparing OS in treatment arms cet. (n=219) vs. bev. (n=217)) for patients with synchronous disease; (p-value: 0.05, HR: 1,26, 95%-CI: 1.0 - 1.59). 436/592 pts suffered from synchronous, 153/592 from metachronous disease (in 3/592 pts the information was not given). Median OS in pts with synchronous disease was 24.5 months and 29.5 in pts with metachronous disease (p-value: 0.02, HR: 0.76, 95%-CI: 0.6 - 0.96). In pts treated in the cetuximab arm metachronous disease (n=77) was associated with a trend towards longer OS when compared to synchronous disease (n= 219) (p-value: 0.13, HR: 0.76, 95%-CI: 0.54 – 1.1). The same effect was present in the bevacizumab arm (p-value: 0.05, HR: 0.73, 95%-CI 0.53 – 1.0) when comparing pts with synchronous disease (n=217) vs. pts. with metachronous disease (n=76). Conclusions: In the FIRE-3 study, metachronous disease was associated with superior OS compared to synchronous disease. This finding was accentuated in the bevacizumab arm. The role of resection of the primary tumor had no impact on survival. Clinical trial information: NCT00433927 .

Magnesium wasting is a frequent side effect of epidermal growth factor receptor (EGFR)-antibody treatment as magnesium-absorption mechanisms are dependent on EGFR signaling. EGFR-inhibition results in decreased renal reabsorption. There is evidence that hypomagnesemia during cetuximab treatment correlates with response. The prognostic role of hypomagnesemia during bevacizumab treatment has not been studied yet. Here, we evaluate the prognostic value of hypomagnesemia in patients with metastatic colorectal cancer treated with FOLFIRI plus cetuximab or bevacizumab as first-line therapy. A total of 391 of 752 patients of the firstline irinotecan study population had magnesium levels measured at baseline and for the first three cycles (6 weeks) of treatment. Of those, 240 had Rat Sarkoma wildtype tumors. Overall hypomagnesemia was more common in the cetuximab compared to the bevacizumab arm (80 vs. 43%,P < 0.005). During therapy, magnesium showed a time-dependent decrease to 80% of baseline in the cetuximab and to 89% in the bevacizumab arm. Whereas magnesium continued to decrease over time in the cetuximab-treated patients, it remained stable in the bevacizumab-treated. Overall response rate (ORR) was associated with higher magnesium at week 6 (20.9 vs. 79.1%,P = 0.041). Bevacizumab-treated patients with magnesium levels below the median value at week 6 had a significantly longer progression-free survival (PFS; 11.7 vs. 9.9 months,P = 0.034; hazard ratio 0.73) and a trend towards longer overall survival (OS) (29.6 vs. 23.2 months,P = 0.089; hazard ratio 0.77). Hypomagnesemia at predefined time points and magnesium nadir had no significant effect on ORR, OS and PFS in the cetuximab arm. Our data show different magnesium kinetics in patients with metastatic colorectal cancer treated with cetuximab or bevacizumab. For patients treated with cetuximab, hypomagnesemia did not have an impact on response and survival. Hypomagnesemia might have a prognostic value in bevacizumab treatment.

Background: Cetuximab-induced skin toxicity (Cet-ST) is positively associated with outcome in metastatic colorectal cancer (mCRC). Besides its predictive relevance for targeted therapy, we investigated its prognostic impact with early tumor shrinkage (ETS) >= 20%, another on-treatment surrogate for clinical outcome in FIRE-3. Patients and methods: FIRE-3 evaluated first-line FOLFIRI (folinic acid, fluorouracil and irinotecan) plus cetuximab (FOLFIRI/Cet) versus FOLFIRI plus bevacizumab (FOLFIRI/Bev) in mCRC patients with RAS-WT tumors (i.e. wild-type in KRAS and NRAS exons 2-4). Retrospective data on Cet-ST that occurred during cycles 1-3 of treatment were correlated with efficacy endpoints, including ETS. To control for guarantee-time bias, only patients who had completed three or more treatment cycles were considered. Results: Of 199 patients treated with FOLFIRI/Cet, 181 (91.0%) completed three or more treatment cycles. A significant survival benefit of FOLFIRI/Cet over FOLFIRI/Bev was only evident in patients developing Cet-ST grade 2-3 [41.0 versus 26.6 months; hazard ratio (HR) = 0.73; 95% confidence interval (CI): 0.61-0.87; P < 0.001] compared with Cet-ST grade 0-1 (HR = 0.90; 95% CI: 0.67-1.20; P = 0.48). Regarding prognosis, Cet-ST grade 2-3 (n = 75; 41.4%), compared with Cet-ST grade 0-1 (n = 106; 58.6%), was associated with prolonged overall survival (OS; HR = 0.62; 95% CI: 0.42-0.91; P = 0.01). In multivariate analysis, both Cet-ST (HR = 0.66; 95% CI: 0.50-0.87; P = 0.003) and ETS (HR = 0.55; 95% CI: 0.41-0.74; P < 0.0001) were independently prognostic for OS. Absence of both Cet-ST grade >= 2 and ETS identified a subgroup of patients with very poor prognosis (median OS 15.1 months). Conclusions: In FIRE-3, the addition of cetuximab to FOLFIRI was associated with superior OS compared with FOLFIRI/Bev only in patients developing Cet-ST grade >= 2. Regarding prognostic relevance, both Cet-ST and ETS were independent and early predictors of survival. The present analysis supports that a combined evaluation of on-treatment parameters such as Cet-ST and ETS may help to guide treatment of mCRC.

4618 Background: APACT was a phase III trial of adjuvant nab-paclitaxel + gemcitabine ( nab-P + Gem) vs Gem alone in patients with resected pancreatic cancer (PC) and the first adjuvant PC trial to use independently assessed DFS as the primary endpoint (DFS by investigator review was a prespecified sensitivity analysis). We examined concordance between independent and investigator DFS review. Methods: For the independent assessment, reviewers determined recurrence by computed tomography or magnetic resonance imaging but were blinded to treatment and clinical data. Investigator-assessed DFS was based on all available data. Concordance was summarized by κ statistics. Patients who did not have recurrence or were alive were censored at the last tumor assessment date with disease-free status or the randomization date if the last tumor assessment with disease-free status was missing. Patients who received new anticancer therapy or cancer-related surgery prior to recurrence or death were censored at the date of last tumor assessment with disease-free status prior to the start of new anticancer therapy or cancer-related surgery or the randomization date if the last tumor assessment date with disease-free status prior to the start of subsequent new anticancer therapy or cancer-related surgery was missing. All censoring rules were the same for analysis of DFS by independent and investigator review. Results: Median DFS by independent review was 19.4 ( nab-P + Gem) vs 18.8 (Gem) months (hazard ratio [HR] 0.88; 95% CI, 0.73 - 1.06; P = 0.18); median investigator-assessed DFS was 16.6 ( nab-P + Gem) vs 13.7 (Gem) months (HR 0.82; 95% CI, 0.69 - 0.97; nominal P = 0.017). Moderate concordance was found between independent- and investigator-assessed DFS (Table); similar results were observed in the nab-P + Gem (concordance, 78%; κ coefficient, 0.56) and Gem alone (concordance, 76%; κ coefficient, 0.53) arms. Conclusions: The results reflect the complexities of defining the recurrence timepoint accurately and suggest that radiological review in the absence of clinical context is suboptimal for recurrence detection in resected PC. These findings may inform future clinical trial design. Registration: EudraCT (2013-003398-91); ClinicalTrials.gov (NCT01964430). Clinical trial information: NCT01964430 . [Table: see text]

Background: New chemotherapy regimens for the treatment of metastatic pancreatic cancer have changed the therapy paradigm. We aimed to assess their impact on the treatment landscape and clinical outcome at our academic institution. Methods: In this single institutional posthoc registry analysis, we assessed characteristics and survival rates from all patients with locally advanced and metastatic pancreatic cancer who started a systemic treatment between 01/2011 and 12/2017. Survival analyses were performed by Kaplan-Meier and Cox proportional hazards model. Results: A total of 301 patients started a systemic treatment in the observation period. In the first line treatment, we observed a shift from the four different main regimens (gemcitabine/nab-paclitaxel, modified FOLFIRINOX, gemcitabine/oxaliplatin +/− erlotinib or gemcitabine alone) to gemcitabine/nab-paclitaxel and modified FOLFIRINOX that add up to more than 80% of administered first line treatments in each of the time cohorts (2011–2013 vs. 2014–2017). The rate for first line modified FOLFIRINOX treatment was balanced between the two groups (19% and 15%). Median overall survival differed significantly between the two time cohorts (8.89 versus 11.9 months, p = 0.035). Survival rates for different first to second line treatment sequences (modified FOLFIRINOX to gemcitabine/nab-paclitaxel, gemcitabine/nab-paclitaxel to fluoropyrimidines plus nanoliposomal irinotecan, or gemcitabine/nab-paclitaxel to fluoropyrimidines plus oxaliplatin) were not significantly different and median overall survival ranged from 14.27 to 15.64 months. Conclusion: Our study provides real-world evidence for the effectiveness of the new chemotherapy regimens and underscores the importance of the choice of the front-line regimen when considering different sequencing strategies.

Background: Targeted therapies offer novel opportunities to explore biomarkers based on their mode of action. Taking this into consideration, we evaluated six angiogenesis-related proteins as potential predictive biomarkers, which expression might predict the benefit of bevacizumab treatment in patients with metastatic colorectal cancer (mCRC). Methods: This was a phase II multicenter, two-armed, randomized study, in which patients with mCRC were treated with XELIRI (capecitabine and irinotecan) plus bevacizumab followed by XELOX (capecitabine and oxaliplatin) plus bevacizumab (Arm A) or the reverse sequence (Arm B). Tissue expression level of six prespecified candidates [microvessel density assessed by CD31, PTEN, αV integrin, CD98hc, uPAR and NRP-1] was analyzed via immunohistochemistry. The prognostic impact on survival was quantified using the Cox regression model. The predictive potential for benefit from Arm A versus Arm B treatment was investigated by fitting an interaction between the biomarkers and treatment assignment within a multivariable Cox model. Results: In total, 74 out of 126 patients were included in the analysis. The expression of PTEN, αV integrin, uPAR and NRP-1 was not associated with progression-free survival (PFS) or overall survival (OS). For the first time, we identified that patients with tumors expressing CD98hc had a longer PFS than patients without CD98hc-expression ( p = 0.032). More importantly, and in accordance with previous studies, low microvessel density was found to be associated with a reduced PFS [adjusted HR per doubling of CD31-expression ( p = 0.53, 95% confidence interval: 0.30–0.95, p = 0.034)]. Conclusions: These results can contribute to the development of a personalized strategy for the treatment of mCRC with bevacizumab.

BACKGROUND:Molecular biomarkers and primary tumour sidedness guide treatment decisions in metastatic colorectal cancer. Comprehensive molecular profiling aims to identify targetable alterations and measure tumour mutational burden (TMB) to enable precision oncology. MATERIAL AND METHODS:FoundationOne® next-generation sequencing identified single-nucleotide variants (SNVs), copy number alterations, high TMB (TMB-H) and high-grade microsatellite instability (MSI-H) in patients treated in the FIRE-3 trial. Data were correlated with objective response rate (ORR), progression-free survival (PFS) and overall survival (OS). RESULTS:Three hundred seventy-three (49.6%) of 752 patients provided material for this analysis. Frequent SNVs included TP53, APC, KRAS, PIK3CA, BRAF, SMAD4 and FBXW7. KRAS, BRAF V600E and SMAD4 mutations were confirmed as prognostic biomarkers by logistic penalised regression for ORR. OS was significantly longer in patients with SMAD4 wild-type (WT) tumours than in those with SMAD4-mutated tumours (hazard ratio = 0.59 [95% confidence interval {CI} = 0.34-1.01], p = 0.05), with a higher probability of ORR [odds ratio, SMAD4 SNV versus WT = 0.32 [95% CI = 0.10-0.98], p = 0.05] when treated with cetuximab. MSI-H (30.0%, p = 0.03) and TMB-H (17.3%, p = 0.003) tumours were enriched by FBXW7 mutations. Numerically lower ORR, OS and PFS were observed in MSI-H tumours. CONCLUSIONS:RAS, BRAF V600E and SMAD4 mutations were identified as poor prognostic biomarkers in patients of the FIRE-3 trial, whereas improved outcome was observed for BRAF non-V600E mutation. SMAD4 mutation might provide predictive relevance for cetuximab efficacy. MSI-H tumours showed numerically lower ORR, OS and PFS.