Histological response, pattern of tumor destruction and clinical outcome after neoadjuvant chemotherapy including bevacizumab or cetuximab in patients undergoing liver resection for colorectal liver metastases

Perioperative Chemotherapy Including Bevacizumab in Potentially Curable Metastatic Colorectal Cancer: Long-Term Follow-Up of the ASSO-LM1 Trial

In 2007, the ASSO-LM1 trial, a multicenter prospective study, was initiated to investigate the resectability (R0) rate following preoperative combination therapy with XELOX and bevacizumab in patients with potentially resectable colorectal liver metastases. Six cycles of systemic therapy were administered preoperatively, although the sixth cycle did not include bevacizumab, resulting in 5 weeks between the last bevacizumab dose and surgery. Treatment with bevacizumab plus XELOX was restarted for another six cycles postoperatively. In total, 43 patients were enrolled in the ASSO-LM1 trial. Eight patients were ineligible for resection due to protocol violation and progression in two patients. The resectability of operated patients was 97% with 34 R0 resections and one R1 resection. Postoperative morbidity occurred in 22% of patients, of which three operative revisions were related to the primary tumor resection. Efficacy results for response in 38 eligible patients confirmed an ORR of 66%, 31% SD and 3% PD according to RECIST. Preoperative grade 3/4 adverse events were 17% diarrhea, 5% HFS and 5% thromboembolic events. Overall survival significantly differed depending upon the fulfillment of adjuvant treatment in curative resected patients (59.1 mo vs. 30.8 mo). In conclusion, the ASSO-LM1 trial is a hypothesis-generating study confirming the prognostic benefits of perioperative therapy with XELOX and bevacizumab in patients with metastatic colorectal cancer confined to the liver.

The Effect of Induction Chemotherapy with VEGF Inhibition on Tumor Response in Synchronously Metastasized Potentially Resectable Colorectal Cancer

(1) Background: The pathological tumor response of the primary tumor to induction chemotherapy in synchronously metastasized colorectal cancer (mCRC) patients has not been investigated. The aim of this study was to compare patients treated with induction chemotherapy combined with vascular endothelial growth factor (VEGF) or with epidermal growth factor receptor (EGFR) antibodies. (2) Methods: We present a retrospective analysis, where we included 60 consecutive patients with potentially resectable synchronous mCRC who received induction chemotherapy combined with either VEGF or EGFR antibodies. The primary endpoint of this study was the regression of the primary tumor, which was assessed by the application of the histological regression score according to Rödel. The secondary endpoints were recurrence-free survival (RFS) and overall survival (OS). (3) Results: A significantly better pathological response and a longer RFS for patients treated with the VEGF antibody therapy compared to those treated with the EGFR antibodies was demonstrated (p = 0.005 for the primary tumor and log-rank = 0.047 for RFS). The overall survival did not differ. The trial was registered with clinicaltrial.gov, number NCT05172635. (4) Conclusion: Induction chemotherapy combined with a VEGF antibody revealed a better pathological response of the primary tumor, leading to a better RFS compared to that with EGFR therapy; this has clinical relevance in patients with potentially resectable synchronously mCRC.

Pathological Evaluation of Resected Colorectal Liver Metastases: mFOLFOX6 Plus Bevacizumab versus mFOLFOX6 Plus Cetuximab in the Phase II ATOM Trial

We compared the preplanned histopathological responses of resected liver metastases from patients who received modified FOLFOX6 plus bevacizumab or modified FOLFOX6 plus cetuximab for liver-limited colorectal metastases in the ATOM trial. Fibrosis and viable tumor cells in tumor regression grade (TRG), infarct-like necrosis in modified TRG (mTRG), and dangerous halo (DH) were assessed. Fifty-five patients (28 and 27 patients in the bevacizumab and cetuximab arms, respectively) were divided into the low (viable tumor cells ≤ 50%) and high (>50%) TRG or mTRG groups. DH was characterized as absent/rare or focal/diffuse. Compared to the bevacizumab arm, the cetuximab arm was more effective, with respect to low TRG (13 vs. 23 patients) and absent/rare DH (14 vs. 19 patients), respectively. Low mTRG was similarly observed in both arms. Low TRG/mTRG and absent/rare DH showed better relapse-free survival (RFS) than high TRG/mTRG and focal/diffuse DH. In the bevacizumab arm, a significant difference in RFS existed between the low and high TRG groups, while in the cetuximab arm, for TRG, mTRG, and DH, the low and absent/rare groups demonstrated significantly longer RFS than the high and focal/diffuse groups, respectively. TRG could estimate RFS in patients who underwent liver metastasectomy after bevacizumab or cetuximab chemotherapy.

Upgraded nomograms for the prediction of complications and survival in patients with colorectal liver metastases treated with neoadjuvant chemotherapy followed by hepatic resection

Background

To establish upgraded nomograms incorporating neoadjuvant chemotherapy (NAC)-related factors and preoperative testing markers to predict postoperative complications, progression-free survival (PFS) and overall survival (OS) in patients with colorectal liver metastases (CRLM).

Methods

Multivariate regression analyses were used to reveal independent predictors for postoperative complications, PFS and OS. Nomograms incorporating independent predictors were constructed, and discrimination and calibration were evaluated. Survival was estimated by the Kaplan-Meier method and compared using the log-rank test.

Results

A nomogram predicting postoperative complications was constructed based on preoperative serum gamma-glutamyl transpeptidase (GGT) ≥36 U/L, major liver resection, intraoperative blood loss ≥300 mL, primary site located in the right hemicolon and primary lymph node metastasis, with an area under the receiver operating characteristic curve (AUROC) of 0.750. The calibration curves and Hosmer-Lemeshow test revealed desirable model calibration (chi-square: 4.47, P=0.88). Moreover, a nomogram for the prediction of PFS was constructed based on tumour regression grade (TRG), primary lymph node metastasis, R0 resection and NAC cycles ≥5, with good discrimination (C-index: 0.663±0.024) and calibration, and one for predicting OS was constructed based on preoperative GGT ≥36 U/L, NAC toxicity, NAC cycles ≥5, primary lymph node metastasis and R0 resection, with favourable discrimination (C-index: 0.684±0.030) and calibration. Significant differences in PFS and OS were observed among patients stratified into three different risk groups (P<0.001) according to total scores based on the nomograms.

Conclusions

This study is the first to establish novel predictive nomograms specifically incorporating TRG, NAC toxicity and serum GGT level for the prediction of postoperative complications, PFS and OS in CRLM patients. The nomograms exhibit favourable discrimination and calibration to guide personalized CRLM management and therapy.

Neo-adjuvant Chemotherapy-Induced Neutropenia Is Associated with Histological Responses and Outcomes after the Resection of Colorectal Liver Metastases

BACKGROUND

Neutropenia, the major adverse event in chemotherapy, is associated with favourable clinical outcome in several solid tumours. We aimed to investigate the predictive value of neo-adjuvant chemotherapy (NAC)-induced neutropenia for the pathological response and prognosis in colorectal liver metastases (CRLM) patients.

METHODS

A retrospective review was performed in 141 CRLM patients receiving NAC followed by liver resection. A logistic regression was applied to analyse potential predictors. A Cox proportional hazards analysis was used to analyse survival.

RESULTS

Neutropenia due to NAC was observed in 42.6% (60/141) of all patients, and grade 3/4 neutropenia was noted in 31.7% (19/60). A pathological response (tumour regression grade (TRG) 1-3) was reported in 46.1% (65/141) of patients. Multivariate analysis showed that neutropenia significantly predicted the favourable pathological response (OR = 3.718, 95% CI 1.716-8.329, P = 0.001), as well as targeted therapy, good differentiation and preoperative CEA < 10 ng/ml as independent predictors of favourable histological response. Of the patients, 54.6% (77/141) had postoperative complications, including 28 major complications (28/77, 36.4%). Severe neutropenia significantly predicted postoperative major complications in multivariate analysis (OR = 4.077, 95% CI 1.184-14.038, P = 0.026). Compared to patients without neutropenia, patients with neutropenia had significantly better progression-free survival (PFS) (P = 0.007; mPFS, 10.2 months vs. 6.7 months). Patients with histological response had significantly better PFS than patients with no histological response (P = 0.001; mPFS, 10.0 months vs. 5.5 months). According to multivariate analyses, neutropenia was a significant predictor for better PFS (HR = 0.613, 95% CI 0.406-0.925, P = 0.020) but not OS.

CONCLUSIONS

For CRLM patients receiving NAC followed by liver resection, NAC-induced neutropenia was a significant predictor of favourable pathological response, postoperative major complications and better prognosis, which makes it useful for CRLM patients in guiding treatment approaches and prognosis assessments.

Objective response rate assessment in oncology: Current situation and future expectations

The tumor objective response rate (ORR) is an important parameter to demonstrate the efficacy of a treatment in oncology. The ORR is valuable for clinical decision making in routine practice and a significant end-point for reporting the results of clinical trials. World Health Organization and Response Evaluation Criteria in Solid Tumors (RECIST) are anatomic response criteria developed mainly for cytotoxic chemotherapy. These criteria are based on the visual assessment of tumor size in morphological images provided by computed tomography (CT) or magnetic resonance imaging. Anatomic response criteria may not be optimal for biologic agents, some disease sites, and some regional therapies. Consequently, modifications of RECIST, Choi criteria and Morphologic response criteria were developed based on the concept of the evaluation of viable tumors. Despite its limitations, RECIST v1.1 is validated in prospective studies, is widely accepted by regulatory agencies and has recently shown good performance for targeted cancer agents. Finally, some alternatives of RECIST were developed as immune-specific response criteria for checkpoint inhibitors. Immune RECIST criteria are based essentially on defining true progressive disease after a confirmatory imaging. Some graphical methods may be useful to show longitudinal change in the tumor burden over time. Tumor tissue is a tridimensional heterogenous mass, and tumor shrinkage is not always symmetrical; thus, metabolic response assessments using positron emission tomography (PET) or PET/CT may reflect the viability of cancer cells or functional changes evolving after anticancer treatments. The metabolic response can show the benefit of a treatment earlier than anatomic shrinkage, possibly preventing delays in drug approval. Computer-assisted automated volumetric assessments, quantitative multimodality imaging in radiology, new tracers in nuclear medicine and finally artificial intelligence have great potential in future evaluations.

Erlotinib inhibits colon cancer metastasis through inactivation of TrkB-dependent ERK signaling pathway

The distal metastasis is the main cause of death in patients with colon cancer. Tyrosine receptor kinase B (TrkB) and ERK signals may be the potential targets for the treatment of colon cancer metastasis. This study aims to investigate whether erlotinib inhibits distant metastasis of colon cancer by regulating TrkB and ERK signaling pathway. Human colon adenocarcinoma cell lines (SW480 and Caco-2) pretreated with exogenous C-X-C motif chemokine ligand 8 (CXCL8) were used to assess the suppressive effect of erlotinib on tumor metastasis, including anoikis, epithelial-mesenchymal transformation (EMT), migration, and invasion. Through TrkB overexpression, Akt suppression, and ERK suppression, the roles of TrkB, Akt, and ERK in erlotinib-induced metastasis inhibition of colon cancer cells were explored. The results showed that erlotinib alleviated CXCL8-induced metastasis of the colon cancer cells. Overexpression of TrkB in colon cancer cells eliminated the effect of erlotinib on anoikis, inhibition of EMT, migration, and invasion, and downregulation of p-ERK and p-Akt. Furthermore, the inhibition of ERK activation instead of Akt activation was found to participate in erlotinib-mediated metastasis resistance, including anoikis, inhibition of EMT, migration, and invasion. In conclusion, erlotinib inhibits colon cancer cell anoikis resistance, EMT, migration, and invasion by inactivating TrkB-dependent ERK signaling pathway.

Nomogram predicted disease free survival for colorectal liver metastasis patients with preoperative chemotherapy followed by hepatic resection

BACKGROUND

Hepatic resection is regarded to as a potentially curative option for colorectal cancer liver metastases (CRLM), but it is associated with a high rate of recurrence. The present study intended to establish an effective nomogram to predict disease free survival (DFS) and select candidates of hepatic resection.

METHODS

The nomogram was based on a retrospective study on 447 CRLM patients treated with preoperative chemotherapy followed by hepatic resection using a multicentric database between January 1st, 2010 and December 31st, 2017. Results were validated using bootstrap resampling on 117 patients. The predictive accuracy and discriminative ability of the nomogram were determined by concordance index (C-index) and calibration curve. Overall survival, disease free survival, and local recurrence rate for patients with colorectal cancer were measured.

RESULTS

Based on multivariate analysis of the primary cohort, independent factors for DFS included tumor size larger than 5 cm, multiple liver metastases(>1), RAS mutation, primary lymph node metastasis and tumor size increase after preoperative chemotherapy. These five factors were all considered in the nomogram. The C-index of the nomogram for predicting survival was 0.675. With external validation, the C-index of the nomogram for the prediction of the DFS was 0.77, which demonstrated that this model has a good level of discriminative ability. For the 382 patients (66.7%) who developed recurrence, the optimal cutoff point for early recurrence was determined to be 12 months after hepatic resection.

CONCLUSIONS

The proposed nomogram demonstrated accurate prognostic prediction of DFS for CRLM patients with preoperative chemotherapy followed by hepatic resection.

A Low Neutrophil to Lymphocyte Ratio Before Preoperative Chemotherapy Predicts Good Outcomes After the Resection of Colorectal Liver Metastases

BACKGROUND

The neutrophil to lymphocyte ratio (NLR) is a marker of inflammation and is associated with poor outcomes. We aimed to evaluate the role of the pretreatment NLR in predicting the outcomes after preoperative chemotherapy in patients with colorectal liver metastases (CRLM).

METHODS

A retrospective review was performed for 183 patients with CRLM. The NLR was measured before chemotherapy, and a receiver operating characteristic (ROC) curve was used to estimate the cutoff value. Logistic regressions were applied to analyze potential predictors of the pathological response. The Cox proportional hazard method was used to analyze survival.

RESULTS

The pre-chemotherapy NLR was 2.4 ± 1.1, whereas the post-chemotherapy NLR was 2.1 ± 1.6 (p < 0.001). The pretreatment NLR of 2.3 was a significant predictive marker for the pathological response. The pathological response rates were 67.1% in the patients with an NLR ≤ 2.3 and 48.1% in patients with an NLR > 2.3 (p = 0.01). Multivariate analysis revealed that the factors independently associated with pathological responses were a low pretreatment NLR (p = 0.043), radiological response to chemotherapy (p < 0.001), first-line chemotherapy (p = 0.001), and targeted therapy (p = 0.002). The median overall survival (OS) and recurrence-free survival (RFS) were worse in the increased NLR cohort than in the low NLR cohort (OS: 31.1 vs. 43.1 months, p = 0.012; RFS: 6.5 vs. 9.4 months, p = 0.06). According to multivariate analyses, a high pretreatment NLR was a significant predictor for both worse OS (HR = 2.43, 95%CI = 1.49-3.94, p < 0.001) and RFS (HR = 1.53, 95%CI = 1.08-2.18, p = 0.017).

CONCLUSIONS

An increased pretreatment NLR was a significant predictor of a poor pathological response and worse prognosis after preoperative chemotherapy. The NLR is a simple biomarker for assessing chemotherapy efficacy.

Differential histopathologic parameters in colorectal cancer liver metastases resected after triplets plus bevacizumab or cetuximab: a pooled analysis of five prospective trials

BACKGROUND

Many factors, including histopathologic parameters, seem to influence the prognosis of patients undergoing resection of colorectal cancer liver metastases (CRCLM), although their relative weight is unclear. Histopathologic growth patterns (HGPs) of CRCLM may affect sensitivity to antiangiogenics. We aimed at evaluating differences in histopathologic parameters of response according to the use of bevacizumab or cetuximab as first-line targeted agents, and at exploring the prognostic and predictive role of HGPs.

METHODS

We performed a comprehensive histopathologic characterisation of CRCLM from 159 patients who underwent secondary resection, after receiving triplets FOLFOXIRI (folinic acid, 5-fluorouracil, oxaliplatin, and irinotecan) or COI (capecitabine, oxaliplatin, and irinotecan) plus bevacizumab (N = 103) vs cetuximab (N = 56) in five first-line no-profit clinical trials.

RESULTS

Both major histopathologic response (tumour regression grade TRG1-2, 32 vs 14%, p = 0.013) and infarct-like necrosis (80 vs 64%, p = 0.035) were significantly higher in the bevacizumab than in the cetuximab group. Achieving major response positively affected relapse-free survival (RFS) (p = 0.012) and overall survival (OS) (p = 0.045), also in multivariable models (RFS, p = 0.008; OS, p = 0.033). In the desmoplastic HGP (N = 28), a higher percentage of major response was reported (57 vs 17% in pushing and 22% in replacement HGP, p < 0.001) and an unsignificant advantage from cetuximab vs bevacizumab was evident in RFS (p = 0.116). In the pushing HGP (N = 66), a significant benefit from bevacizumab vs cetuximab (p = 0.017) was observed. No difference was described in the replacement HGP (N = 65, p = 0.615).

CONCLUSIONS

The histopathologic response is the only independent determinant of survival in patients resected after triplets plus a biologic. When associated with triplet chemotherapy, bevacizumab induces a higher histopathologic response rate than cetuximab. The assessment of HGPs should be further explored as a predictor of benefit from available targeted agents.

FLT-PET for early response evaluation of colorectal cancer patients with liver metastases: a prospective study

BACKGROUND

Fluoro-L-thymidine (FLT) is a positron emission tomography/computed tomography (PET/CT) tracer which reflects proliferative activity in a cancer lesion. The main objective of this prospective explorative study was to evaluate whether FLT-PET can be used for the early evaluation of treatment response in colorectal cancer patients (CRC) with liver metastases. Patients with metastatic CRC having at least one measurable (>1 cm) liver metastasis receiving first-line chemotherapy were included. A FLT-PET/CT scan was performed at baseline and after the first treatment. The maximum and mean standardised uptake values (SUVmax, SUVmean) were measured. After three cycles of chemotherapy, treatment response was assessed by CT scan based on RECIST 1.1.

RESULTS

Thirty-nine consecutive patients were included of which 27 were evaluable. Dropout was mainly due to disease complications. Nineteen patients (70%) had a partial response, seven (26%) had stable disease and one (4%) had progressive disease. A total of 23 patients (85%) had a decrease in FLT uptake following the first treatment. The patient with progressive disease had the highest increase in FLT uptake in SUVmax. There was no correlation between the response according to RECIST and the early changes in FLT uptake measured as SUVmax (p = 0.24).

CONCLUSIONS

No correlation was found between early changes in FLT uptake after the first cycle of treatment and the response evaluated from subsequent CT scans. It seems unlikely that FLT-PET can be used on its own for the early response evaluation of metastatic CRC.

Pathologic response after preoperative therapy predicts prognosis of Chinese colorectal cancer patients with liver metastases

BACKGROUND

Pathologic response is evaluated according to the extent of tumor regression and is used to estimate the efficacy of preoperative treatment. Several studies have reported the association between the pathologic response and clinical outcomes of colorectal cancer patients with liver metastases who underwent hepatectomy. However, to date, no data from Chinese patients have been reported. In this study, we aimed to evaluate the association between the pathologic response to pre-hepatectomy chemotherapy and prognosis in a cohort of Chinese patients.

PATIENTS AND METHODS

In this retrospective study, we analyzed the data of 380 liver metastases in 159 patients. The pathologic response was evaluated according to the tumor regression grade (TRG). The prognostic role of pathologic response in recurrence-free survival (RFS) and overall survival (OS) was assessed using Kaplan-Meier curves with the log-rank test and multivariate Cox models. Factors that had potential influence on pathologic response were also analyzed using multivariate logistic regression and Kruskal-Wallis/Mann-Whitney U tests.

RESULTS

Patients whose tumors achieved pathologic response after preoperative chemotherapy had significant longer RFS and OS than patients whose tumor had no pathologic response to chemotherapy (median RFS: 9.9 vs. 6.5 months, P = 0.009; median OS: 40.7 vs. 28.1 months, P = 0.040). Multivariate logistic regression and Kruskal-Wallis/Mann-Whitney U tests showed that metastases with small diameter, metastases from the left-side primary tumors, and metastases from patients receiving long-duration chemotherapy had higher pathologic response rates than their control metastases (all P < 0.05). A decrease in the serum carcinoembryonic antigen (CEA) level after preoperative chemotherapy predicted an increased pathologic response rate (P < 0.05). Although the application of targeted therapy did not significantly influence TRG scores of all cases of metastases, the addition of cetuximab to chemotherapy resulted in a higher pathologic response rate when combined with irinotecan-based regimens rather than with oxaliplatin-based regimens.

CONCLUSIONS

We found that the evaluation of pathologic response may predict the prognosis of Chinese colorectal cancer patients with liver metastases after preoperative chemotherapy. Small tumor diameter, long-duration chemotherapy, left primary tumor, and decreased serum CEA level after chemotherapy are associated with increased pathologic response rates.

Prognostic impact of margin status in liver resections for colorectal metastases after bevacizumab

BACKGROUND

Margin status with resection of colorectal liver metastasis (CRLM) was an important prognostic factor in the years before the introduction of biological chemotherapy. This study examined outcomes following CRLM resection in patients who received neoadjuvant chemotherapy with or without the monoclonal antiangiogenic antibody bevacizumab.

METHODS

Patients who underwent surgery for CRLM at the Johns Hopkins Hospital between 2000 and 2015 were identified from an institutional database. Data regarding surgical margin status, preoperative bevacizumab administration and overall survival (OS) were assessed using multivariable analyses.

RESULTS

Of 630 patients who underwent CRLM resection, 417 (66·2 per cent) received neoadjuvant chemotherapy with (214, 34·0 per cent) or without (203, 32·2 per cent) bevacizumab. The remaining 213 (33·8 per cent) did not receive neoadjuvant chemotherapy. Univariable analysis found that positive margins were associated with worse 5-year OS than R0 resection (36·2 versus 54·9 per cent; P = 0·005). After dichotomizing by the receipt of preoperative bevacizumab versus chemotherapy alone, the prognostic value of pathological margin persisted among patients who did not receive preoperative bevacizumab (5-year OS 53·0 versus 37 per cent after R0 versus R1 resection; P = 0·010). OS was not significantly associated with margin status in bevacizumab-treated patients (5-year OS 46·8 versus 33 per cent after R0 versus R1 resection; P = 0·081), in whom 5-year survival was slightly worse (presumably reflecting more advanced disease) than among patients treated with cytotoxic agents alone. Pathological margin status was not significantly associated with 5-year OS in patients with a complete or near-complete response to chemotherapy and bevacizumab (43 versus 30 per cent after R0 versus R1 resection; P = 0·917), but this may be due to a type II error.

CONCLUSION

The impact of margin status varied according to the receipt of bevacizumab. Bevacizumab may have a role to play in improving outcomes among patients with more advanced disease.

Prognostic factors of successful on-purpose tumor biopsies in metastatic cancer patients included in the SHIVA prospective clinical trial

PURPOSE

To identify patient/tumor characteristics associated with success of biopsy in patients who received multiple lines of chemotherapy.

METHODS

Patients with refractory cancer from our center, who were included in a prospective randomized phase II trial comparing targeted therapies based on molecular profile of tumors versus conventional chemotherapy, were retrospectively included in this IRB-approved study. All patients had a biopsy of a tumor lesion performed during surgery, or using CT/palpation/endoscopic guidance. A biopsy was considered successful if the neoplastic cellularity was greater than 30%. Primary lesion, size and location of biopsied lesion, on-going chemotherapy and the differential attenuation between non-enhanced and venous phase (HU) for CT-guided biopsied lesions were recorded.

RESULTS

228 patients (age=59±15yo; M/F=1.9) were included. One hundred and sixty biopsies (72%) of the 221 biopsies performed were successful. Prognostic factors of biopsy success were: no ongoing chemotherapy, surgical or palpation-guided biopsy, lymph nodes/soft tissue location(P <0.01). Among the 221 performed biopsies, 122 (55%) were performed using CT guidance and 82 (67%) were successful. In this subgroup, biopsied lesions located in lymph nodes/soft tissue were associated with a higher success rate while lung location was associated with failure (P <0.01). The mean differential attenuation was significantly higher in lesions with a successful biopsy (P <0.001).

CONCLUSION

Success of biopsy was less frequent with CT guidance than with surgical or palpation-guided biopsy and was higher in soft tissues and lymph nodes than that in visceral metastasis. Ongoing chemotherapy decreased tumor cell content and consequently the success of the biopsy samples for molecular profiling.

Efficacy and safety of anti-epidermal growth factor receptor therapy compared with anti-vascular endothelial growth factor therapy for metastatic colorectal cancer in first-line and second-line therapies: a meta-analysis

Aim

This study aimed to compare anti-epidermal growth factor receptor (anti-EGFR) therapy and anti-vascular endothelial growth factor therapy as first-line and second-line therapies in patients with KRAS exon 2 codon 12/13 wild-type (KRAS-WT) metastatic colorectal cancer (mCRC).

Methods

Major databases were systematically searched. The hazard ratio (HR), odds ratio (OR), and 95% confidence intervals (95% CIs) were used to estimate the effect measures. Review Manager software version 5.3 was used for statistical analysis.

Results

Seven trials including ten articles were eligible in the meta-analysis. The patients treated with anti-EGFR as first-line therapy showed a longer overall survival (OS) for KRAS-WT and all RAS wild-type (RAS-WT) mCRC (HR =0.81, 95% CI: 0.72–0.92, P<0.01, n=5; HR =0.78, 95% CI: 0.66–0.93, P<0.01, n=3, respectively). The objective response rate (ORR) was better with the anti-EGFR therapy for KRAS-WT and all RAS-WT mCRC (OR =1.32, 95% CI: 1.11–1.56, P<0.01, n=5; OR =1.55, 95% CI: 1.21–2.00, P<0.01, n=3, respectively). There was no difference in progression-free survival (PFS) for KRAS-WT mCRC and all RAS-WT mCRC between the two groups (HR =1.00; 95% CI: 0.92–1.09, P=0.99, n=4; HR =0.92, 95% CI: 0.71–1.19, P=0.52, n=3, respectively). In addition, two trials provided data on the second-line therapy; there was no significant difference in OS and PFS for the second-line therapy, but a significant improvement in ORR was found in the anti-EGFR group (OR =1.91, 95% CI: 1.16–3.16, P=0.01, n=2). No difference in the conversion therapy (OR =1.34; 95% CI: 0.91–1.99; P=0.14, n=4) was observed between the two therapies.

Conclusion

Our results indicate that anti-EGFR therapy is superior to anti-vascular endothelial growth factor therapy for OS and ORR as a first-line therapy for KRAS-WT mCRC. In the second-line therapy, there was no significant difference in the survival outcomes on the basis of OS and PFS between the two groups. However, ORR improved significantly in the anti-EGFR group.

Equivalent cross-relaxation rate imaging and diffusion weighted imaging for early prediction of response to bevacizumab-containing treatment in colorectal liver metastases-preliminary study

PURPOSE

To evaluate and compare the usefulness of equivalent cross-relaxation rate (ECR) imaging (ECRI) and diffusion-weighted imaging (DWI) in the early prediction of the response of bevacizumab-containing treatments of colorectal liver metastases.

METHODS AND MATERIAL

Seven patients received bevacizumab-containing treatments for colorectal liver metastases. Serial magnetic resonance imaging was performed to evaluate responses before and 2 weeks after starting chemotherapy. In the ECRI, we adopted the off-resonance technique for preferential saturation of immobile protons to evaluate the ECR values. A single saturation transfer pulse frequency was used at a frequency of 3.5 ppm downfield from the water resonance. In the DWI, the apparent diffusion coefficient (ADC) value commonly used with two b-values was acquired by using diffusion weightings of 0 and 800 s/mm². The region of interest of the metastatic lesions in the liver was separately measured by ECRI and DWI. Tumor response was assessed by response evaluation criteria in solid tumors criteria 8 weeks after starting chemotherapy.

RESULTS

In this study, we had four responders and three nonresponders. There was a significant difference in the pretreatment ECR values between the responders and nonresponders (P=.01); there was no significant difference in the ADC values between the two groups. Analysis of the percentage difference between the pretreatment and post-treatment values, termed as percentage change, showed that there were no significant differences in the percentage change of the ADC values between both groups; however, the percentage change in the ECR value was significantly greater for the responders than for the nonresponders (-41.6%±17.1% vs. -12.9%±6.9%, respectively; P=.04).

CONCLUSION

The pretreatment ECR value and percentage change of the ECR value 2 weeks after starting chemotherapy were useful parameters in the early prediction of response to bevacizumab-containing treatment in colorectal liver metastases.

Pathological responses after angiogenesis or EGFR inhibitors in metastatic colorectal cancer depend on the chemotherapy backbone

Background:

Optimal preoperative treatment before colorectal cancer metastases (CRCM) resection remains unclear. This study evaluated pathological responses (pR) in CRCM resected after chemotherapy alone or combined with angiogenesis or epidermal growth factor receptor (EGFR) inhibitors.

Methods:

Pathological response was retrospectively evaluated on 264 resected metastases from 99 patients. The proportion of responding metastases after different preoperative treatments was reported and compared. Patient's progression-free survival (PFS) and overall survival (OS) were compared based on pR.

Results:

The combination of anti-angiogenics with oxaliplatin-based chemotherapy resulted in more pR than when they were combined with irinotecan-based chemotherapy (80% vs 50% P<0.001). Inversely, the combination of EGFR inhibitors with oxaliplatin-based chemotherapy seemed to induce fewer pR than when they were combined with irinotecan-based treatment (53% vs 72% P=0.049). Overall survival at 5 years was improved for patients with a pR in all resected metastases compared with those who did not achieve a pR (68.5% vs 32.6% P=0.023) and this response was the only factor predicting OS in a multivariate analysis.

Conclusion:

The chemotherapy partner combined with angiogenesis or EGFR inhibitors influenced pR in resected CRCM. In our exploratory analysis anti-angiogenic/oxaliplatin-based regimens and anti-EGFR/irinotecan-based regimens were associated with the highest pR. Prospective randomised trials should be performed to validate these observations.