Switching from FOLFIRI plus cetuximab to FOLFIRI plus bevacizumab based on early tumor shrinkage in RAS wild-type metastatic colorectal cancer: A phase II trial (HYBRID)

BACKGROUND

Long-term anti-EGFR antibody treatment increases the risk of severe dermatologic toxicities. This single-arm, phase II trial aimed to investigate the strategy of switching from cetuximab to bevacizumab in combination with FOLFIRI based on early tumor shrinkage (ETS) in patients with RAS wild-type metastatic colorectal cancer (mCRC).

METHODS

Radiologic assessment was performed to evaluate ETS, defined as ≥20% reduction in the sum of the largest diameters of target lesions 8 weeks after the introduction of FOLFIRI plus cetuximab. ETS-negative patients switched to FOLFIRI plus bevacizumab, whereas ETS-positive patients continued FOLFIRI plus cetuximab for eight more weeks, with a switch to FOLFIRI plus bevacizumab thereafter. The primary endpoint was progression-free survival.

RESULTS

This trial was prematurely terminated due to poor accrual after a total enrollment of 30 patients. In 29 eligible patients, 7 were ETS-negative and 22 were ETS-positive. Two ETS-negative patients and 17 ETS-positive patients switched to FOLFIRI plus bevacizumab 8 weeks and 16 weeks after initial FOLFIRI plus cetuximab, respectively. Median progression-free and overall survival durations were 13.4 and 34.7 months, respectively. Six (20%) patients experienced grade ≥3 paronychia, which improved to grade ≤2 by 18 weeks. Grade ≥3 acneiform rash, dry skin, and pruritus were not observed in any patients.

CONCLUSIONS

Our novel treatment strategy delivered acceptable survival outcomes and reduced severe dermatologic toxicities.

Neutrophil-to-Lymphocyte Ratio and Early Tumor Shrinkage as Predictive Biomarkers in Unresectable Hepatocellular Carcinoma Patients Treated With Lenvatinib, PD-1 Inhibitors, in Combination With TACE

Purpose: The purpose of this prospective observational study was to investigate the relationship between pretreatment neutrophil-to-lymphocyte ratio (NLR) and posttreatment early tumor shrinkage (ETS), and clinical outcomes in patients with unresectable hepatocellular carcinoma (uHCC) who received lenvatinib, programmed death-1 inhibitors plus transcatheter arterial chemoembolization. Patients and Methods: A total of 63 uHCC patients were treated with this triple combination. Multivariate analyses to determine the independent factors associated with overall survival (OS) were employed. The link between NLR and clinical results was further analyzed. Furthermore, the predictive value of combining NLR with ETS should be investigated to stratify patients receiving treatment for survival benefits. Results: Progression-free survival and OS were 9.8 and 23.0 months, respectively, with a median follow-up of 20.8 months. On a multivariate analysis of OS, NLR was the only independent prognostic factor. Patients with NLR low (NLR < 3.2) had longer progression-free survival (19.3 vs 7.3 months, P < 0.001) and OS (28.9 vs 16.9 months, P < 0.001), higher objective response rate (86.7% vs 39.4%, P < 0.001), and a higher chance of achieving ETS ≥ 10% (ETS high) (73.3% vs 21.1%, P < 0.001) compared with patients with NLR high (NLR ≥ 3.2). The Spearman correlation analysis also showed the strong consistency between NLR and ETS (R2 = 0.6751). In the subgroup analysis, greater OS benefit was found in the NLR low/ETS high group than the NLR high/ETS low group (χ2 = 31.258, P < 0.001), while there was no survival difference for patients in the NLR low/ETS low group compared with in the NLR high/ETS high group (χ2 = 0.046, P = 0.830). Conclusion: NLR has the potential to identify which patients would benefit from this triple therapy, and when combined with ETS, it has the potential to provide greater predictive power in selecting the appropriate candidates for this combination treatment.

Relation of cetuximab-induced skin toxicity and early tumor shrinkage in metastatic colorectal cancer patients: results of the randomized phase 3 trial FIRE-3 (AIO KRK0306)

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.

Depth of Response and Early Tumor Shrinkage for Predicting Clinical Outcomes in HER2-Positive Metastatic Breast Cancer Treated with Trastuzumab

Background

To evaluate whether the depth of response (DepRe) and early tumor shrinkage (ETS) are predictive factors of clinical outcomes in HER2-positive metastatic breast cancer (mBC) patients treated with trastuzumab.

Methods

We performed a retrospective study of 100 HER2-positive mBC patients who received trastuzumab combined with chemotherapy as first-line treatment. ETS and DepRe were calculated. We employed Youden’s index to determine the optimal cutoff value of ETS and DepRe for predicting progression-free survival (PFS) and overall survival (OS). We used Kaplan–Meier analysis, Log-rank tests, and Cox proportional hazards regression models to evaluate the impacts of ETS and DepRe on clinical outcomes.

Results

The optimal cutoff values were 30% for ETS and 40% for DepRe; ETS and DepRe were observed in 51.0% (51/100) and in 56.0% (56/100) of patients, respectively. Both ETS≥30% and DepRe≥40% were significant tumor-size metrics for predicting PFS (ETS: median 1.43 vs 0.69 years, hazard ratio [HR] = 0.384; 95% confidence interval [CI]: 0.245 to 0.601; P=0.000030; DepRe: median 1.43 vs 0.59 years, HR = 0.390; 95% CI: 0.250 to 0.609; P=0.0000034), but only DepRe≥40% was a significant predictor for OS (median 4.02 vs 3.07 years, HR = 0.484; 95% CI: 0.255 to 0.919; P = 0.027). Multivariate analyses also identified DepRe as an independent prognostic factor for PFS (HR = 0.52; 95% CI: 0.29 to 0.93; P = 0.028) and OS (HR=0.37; 95% CI:0.15 to 0.90; P = 0.029).

Conclusion

ETS≥30% and DepRe≥40% were significant predictors of better clinical outcomes in mBC patients treated with first-line trastuzumab-based chemotherapy. Further validation in prospective trials with larger patient populations is needed.

Early Tumor Shrinkage as a Predictive Factor for Outcomes in Hepatocellular Carcinoma Patients Treated with Lenvatinib: A Multicenter Analysis

We investigated the association between early tumor shrinkage (ETS) and treatment outcome in patients with hepatocellular carcinoma treated with lenvatinib (LEN). A retrospective analysis was performed in 104 patients. ETS was defined as tumor shrinkage at the first evaluation in the sum of target lesions’ longest diameters from baseline according to the Response Evaluation Criteria in Solid Tumors (RECIST). The median overall survival (OS) was not reached, whereas the median progression-free survival (PFS) was 5.0 months. The receiver operating characteristic curve analysis in differentiating long-term responders (PFS ≥ 5.0 months) from short-term responders (PFS < 5.0 months) revealed an ETS cut-off value of 10%. ETS ≥ 10% was significantly correlated with better PFS and OS compared with ETS < 10%. Additionally, ETS ≥ 10% showed a better discrimination ability on prognosis compared with modified RECIST-based objective response at the first evaluation. Multivariate analysis confirmed ETS ≥ 10% as an independent predictor of better OS, as well as a Child–Pugh score of 5 and macrovascular invasion. In conclusion, ETS ≥ 10% was strongly associated with outcome in patients treated with LEN. This biomarker could allow earlier assessment of the treatment response and guide treatment decision-making for HCC.

Spindle cell renal cell carcinoma diagnosed after sunitinib treatment for chromophobe renal cell carcinoma

INTRODUCTION

Chromophobe renal cell carcinoma presents in early pathological stages with a lower risk of metastasis. However, aggressive features and metastasis can occur. A rare case of rapidly progressive disease with histological changes is presented.

CASE PRESENTATION

A 56-year-old woman had a right renal tumor with multiple lymph node metastases, and the pathological diagnosis of the biopsy specimens from the primary tumor was chromophobe renal cell carcinoma. After sunitinib treatment, the metastatic lymph node had decreased in size and the numbers of circulating tumor cells were decreased, consequently, cytoreductive nephrectomy was performed. However, rapid progression of lymph node metastases was observed. Histopathological examination showed that the renal tumor was diagnosed as spindle cell renal carcinoma.

CONCLUSION

It appears that the primary tumor underwent epithelial-mesenchymal transition; further tissue specimen collection and analysis might be needed.

Early response evaluation during preoperative chemotherapy for colorectal liver metastases: Combined size and morphology-based criteria predict pathological response and survival after resection

BACKGROUND

Short treatment-duration with early restaging is crucial to avoid liver injury after preoperative chemotherapy (preopCTX) for colorectal liver metastases (CRLM). Response evaluation according to response evaluation criteria in solid tumors (RECIST) criteria implies several limitations. Early tumor shrinkage (ETS; ≥20% size reduction <6-12 weeks) or morphological criteria (MC) may better predict oncological outcome.

METHODS

In patients undergoing resection after preopCTX between 2003-2017 pathological and radiological response was reassessed according to Blazer classification, ETS, MC, and RECIST within 90 days and correlated with survival.

RESULTS

Seventy-two patients were included, with a median of two (1-10) liver lesions, 53% bilobar involvement, and 7% extrahepatic disease. PreopCTX was applied for 3 months in median (1-6). During restaging after a median of 62 days, presence of ETS was associated with improved median overall survival (OS; 57.1 vs 33.7 months; P = .010) and disease-free survival (16 vs 7.2 months; P = .025). MC significantly correlated with major pathological response (P = .021). When combining ETS with optimal MC, presence of one or both factors was associated with pathological response (61.5% and 92.3%; P = .044) and OS in log-rank (P = .011), and multivariable analysis (hazard ratio [HR] 0.41; 95% confidence interval [CI], 0.19-0.90 and HR 0.32; 95%CI, 0.11-0.97).

CONCLUSION

Response-grading by combined ETS/MC criteria less than 90 days after preopCTX initiation predicts pathological response and postoperative survival in CRLM.

Early Tumor Shrinkage and Depth of Response Evaluation in Metastatic Pancreatic Cancer Treated with First Line Chemotherapy: An Observational Retrospective Cohort Study

Early tumor shrinkage (ETS) and depth of response (DoR) predict favorable outcomes in metastatic colorectal cancer. We aim to evaluate their prognostic role in metastatic pancreatic cancer (PC) patients treated with first-line modified-FOLFIRINOX (FOLFOXIRI) or Gemcitabine + Nab-paclitaxel (GemNab). Hence, 138 patients were tested for ETS, defined as a ≥20% reduction in the sum of target lesions’ longest diameters (SLD) after 6–8 weeks from baseline, and DoR, i.e., the maximum percentage shrinkage in the SLD from baseline. Association of ETS and DoR with progression-free survival (PFS) and overall survival (OS) was assessed. ETS was reached in 49 patients (39.5% in the FOLFOXIRI, 29.8% in the GemNab group; p = 0.280). In the overall population, ETS was significantly associated with better PFS (8.0 vs. 4.8 months, p < 0.001) and OS (13.2 vs. 9.7 months, p = 0.001). Median DoR was −27.5% (−29.4% with FOLFOXIRI and −21.4% with GemNab, p = 0.016): DoR was significantly associated with better PFS (9.0 vs. 6.7 months, p < 0.001) and OS (14.3 vs. 11.1 months, p = 0.031). Multivariate analysis confirmed both ETS and DoR are independently associated with PFS and OS. In conclusion, our study added evidence on the role of ETS and DoR in the prediction of outcome of PC patients treated with first-line combination chemotherapy.

Two cases of lymphangitic carcinomatosis as the primary symptom of colorectal carcinoma that achieved complete remission using combination anti-EGFR antibody therapy

Clinicians often encounter cases of pulmonary lymphangitic carcinomatosis when treating patients with cancer. When such a condition develops before the diagnosis of cancer, its diagnosis is often challenging. Herein, we report about two patients with colorectal carcinoma diagnosed after the identification of lymphangitic carcinomatosis, which achieved complete remission with combination anti-epidermal growth factor receptor (anti-EGFR) antibody therapy. In case 1, a 74-year-old woman presented with cough and dyspnea that had persisted for 1 month. She had unresectable advanced carcinoma of the sigmoid colon with lymphangitic carcinomatosis. Her respiratory status gradually deteriorated due to the disease. Thus, FOLFIRI plus cetuximab therapy was initiated. Her dyspnea rapidly resolved with the treatment, and complete remission of lymphangitic carcinomatosis was achieved. In case 2, a 46-year-old man presented with fever and dyspnea that had persisted for 1 month. He had unresectable advanced carcinoma of the transverse colon with lymphangitic carcinomatosis. FOLFOXIRI therapy was then initiated. However, his respiratory status did not improve. Therefore, his treatment was immediately switched to FOLFIRI plus panitumumab. His dyspnea rapidly resolved with the treatment, and complete remission of lymphangitic carcinomatosis was achieved. In oncologic emergencies, such as lymphangitic carcinomatosis, requiring an early response to treatment, the administration of anti-EGFR antibodies may be a highly effective treatment option.

Early tumor shrinkage as a predictive factor of metastatic renal cell carcinoma in molecular targeted therapy: A single institutional study

The aim of the present study was to investigate the impact of metastatic sites and early tumor shrinkage (eTS) as prognostic predictive factors of metastatic renal cell carcinoma (mRCC) in molecular targeted therapy. A total of 209 advanced RCC cases treated with sorafenib, sunitinib, axitinib, pazopanib, temsirolimus and everolimus from our single institution were included in the present study. Several known prognostic predictive factors, including metastatic sites and the rate of eTS, were analyzed by Kaplan-Meier survival estimate analysis followed by Cox's proportional hazards model analysis. eTS was measured by three independent physicians. Four metastatic sites in the liver, bone, lymph nodes and brain as well as greater eTS were identified as potential independent predictors of overall survival (OS) in several cohorts: i) Metastatic RCC (n=194); ii) metastatic clear cell RCC (n=119); and iii) mRCC patients with eTS data (n=127). In sub-analyses of patients treated with each 1st line tyrosine kinase inhibitor, eTS was identified as a potentially potent predictor of OS in patients treated with axitinib. The liver, bone, lymph nodes, brain metastases and eTS were identified as independent predictive factors of OS by analyzing a limited Japanese cohort.

Phase II trial of biweekly cetuximab and irinotecan as third-line therapy for pretreated KRAS exon 2 wild-type colorectal cancer

Efficacy and safety of biweekly cetuximab plus irinotecan were evaluated to provide guidance for its use in Japan as third-line treatment for pretreated metastatic colorectal cancer (mCRC) patients harboring wild-type KRAS exon 2. Objective response rate (ORR) was used as primary endpoint based on an expected proportion of 0.23 with confidence width of 0.298 (95% CI, 0.105-0.403), which showed 35 to be the minimal participant number. Forty patients, refractory to first- and second-line chemotherapy containing irinotecan, oxaliplatin, and fluoropyrimidine, were enrolled. ORR and disease control rate were 25.0% (95% CI: 11.5-38.4) and 72.5% (95% CI: 56.8-86.4), respectively. Median progression-free survival (PFS), overall survival (OS), and number of courses were 5.70 months (95% CI: 2.7-7.9), 15.1 months (95% CI: 11.8-19.0), and 10.5 (range: 3.0-31.0), respectively. Grade 3 adverse events were skin toxicity (12.5%), diarrhea (10.0%), neutropenia (5.0%), febrile neutropenia (5.0%), nausea (5.0%), anorexia (5.0%), and fatigue (2.5%). C_max mean was 723.2 μg/mL after first dose. High area under the curve (AUC)_last variance was associated with t_1/2 range of 131.2-1209.6 hours (median, 174.4 hours). Early tumor shrinkage (ETS) and median depth of response were 25.0% and 13.0%, respectively. Mutation frequencies in KRAS exon 3 or 4, NRAS, BRAF, and PIK3CA were 5.5%, 2.7%, 8.3%, and 5.5%, respectively. Multivariate Cox regression analysis assessed whether any gene mutations and ETS are predictors for PFS, and whether performance status, synchronous metastasis, and ETS are predictors for OS. Importantly, the data provide guidance for a biweekly cetuximab plus irinotecan regimen in mCRC patients.

Early tumor shrinkage served as a prognostic factor for patients with stage III non-small cell lung cancer treated with concurrent chemoradiotherapy

BACKGROUND

Lung cancer is the most common cause of cancer death. About 80% of patients are diagnosed at stage III in the non-small cell lung cancer (NSCLC). It is extremely important to understand the progression of this disease which has low survival times despite the advancing treatment modalities. We aimed to investigate the relationship between early tumor shrinkage (ETS) after initial concurrent chemoradiotherapy (C-CRT) and survival outcome in patients with stage III (NSCLC).

METHODS

A retrospective review of 103 patients with stage III NSCLC who had received C-CRT from January 2006 to October 2011 was performed. Patients were treated with systemic chemotherapy regimen of Cisplatin/Vp-16 and concurrent thoracic radiotherapy at a median dose of 66 Gy (range 60-70 Gy). All patients received a computed tomography (CT) examination before treatment. Also subsequently, chest CT scans were performed with the same imaging parameters at approximately 5 weeks after the initiation of treatment. ETS is here stratified by a decrease in tumor size ≥30% and <30% in the longest dimension of the target lesion within 5 weeks.

RESULTS

Of the 103 patients, 59 ones showed a 30% decrease in tumor size, and the rest displayed a decrease of <30%. ETS showed no significant correlation with age, T classification, N classification, histological classification, smoking status, G classification, EGFR status, or acute pulmonary toxicity. In the current retrospective clinical study, Kaplan-Meier curves showed that patients with ETS ≥ 30% had a better progression-free survival and overall survival. The univariate and multivariate Cox regression analyses indicated that ETS < 30% was associated with a significantly increased risk of cancer-related death (P < .05) in stage IIINSCLC.

CONCLUSIONS

ETS may be served as a useful prognostic factor to predict the outcome of stage III NSCLC patients treated with CCRT.

A novel therapeutic strategy of personalized medicine based on anti-epidermal growth factor receptor monoclonal antibodies in patients with metastatic colorectal cancer

Achieving tumor shrinkage may be a clinically relevant improvement in the treatment of metastatic colorectal cancer (mCRC). The present study attempted to evaluate early tumor shrinkage (ETS) and deepness of response over 6-8 courses of therapy, which were assessed previously in first-line trials of anti-epidermal growth factor receptor (EGFR) monoclonal antibodies. A total of 37 patients with mCRC that was considered unresectable or borderline resectable were enrolled in the study. Patients exhibited the wild-type RAS gene, and anti-EGFR monoclonal antibodies were used as the first-line treatment in the Department of Surgical Oncology at Gifu University School of Medicine (Gifu, Japan) between January 2010 and March 2017. Tumor shrinkage and other characteristics were evaluated according to the Response Evaluation Criteria In Solid Tumors (RECIST) classifications (version 1.1). The 3-year overall survival (OS) rate was >60.0% for all cases (n=37). The mean tumor shrinkage rate in the right side of the colon according to the RECIST classifications was -11.1%, whereas that for CRC on the left side showed a statistically significant difference at -54.0% (P=0.042). In addition, the rates of OS for stable disease + progressive disease compared with partial response + complete response, and those of OS for conversion therapy compared with non-conversion therapy were significantly different (both P<0.001). Carcinoembryonic antigen (CEA) was suggested to be a possible predictive factor for convalescence due to the 50% drop in its value after the 6-8 courses of therapy. Overall, the predictive performance of ETS with respect to PFS and OS is at least as good as the standard RECIST response, with the advantage of an earlier assessment, and this may improve convalescence, with CEA as a marker in support of ETS over a clinical treatment course. In RAS wild-type patients, it is important to evaluate the rate of tumor shrinkage from the beginning of the first-line treatment until 6-8 courses of anti-EGFR monoclonal antibodies have been administered.

Depth of response is a significant predictor for long-term outcome in advanced gastric cancer patients treated with trastuzumab

Purpose

We aimed to determine and compare the predictive values of depth of response (DpR) and early tumor shrinkage (ETS) on long-term outcomes in gastric cancer patients treated with trastuzumab.

Results

From a total of 368 computed tomography examinations, DpR and ETS were evaluated. DpR was a significant tumor-size metric in predicting PFS and OS, and showed better discriminatory ability (higher Cτ indices, 0.6957 for PFS; 0.7191 for OS) than ETS. DpR ≥ 45% (vs. < 45%) was the optimal cutoff value, as it was best able to identify patients with longer PFS (median 9.0 vs. 6.3 months, hazard ratio [HR] = 0.608; 95% confidence interval [CI]: 0.335 to 1.104; P = 0.102) and OS (median 23.5 vs. 13.1 months, HR = 0.441; 95% CI: 0.203 to 0.955; P = 0.038).

Materials and Methods

Sixty-one gastric cancer patients who received first-line trastuzumab-based chemotherapy were assessed for DpR and ETS. We employed Kaplan-Meier estimates, log-rank tests, Cox proportional hazards regression models, time-dependent receiver operating characteristics, and Youden's J index to evaluate and determine cutoff values of DpR and ETS as predictors of progression-free survival (PFS) and overall survival (OS).

Conclusions

DpR and ETS were significant predictors of long-term outcomes in gastric cancer patients treated with first-line trastuzumab. Validation in prospective trials with larger patient populations is needed.

Early tumor shrinkage as a predictor of favorable outcomes in patients with advanced pancreatic cancer treated with FOLFIRINOX

There are several reports on the correlation between early tumor shrinkage (ETS) or depth of response (DpR) and survival in chemotherapies for colorectal cancer; however, few studies have investigated it in pancreatic cancer. We therefore investigated whether the ETS will predict outcomes in 59 patients with advanced pancreatic cancer treated with FOLFIRINOX therapy. The association of ETS with progression-free survival (PFS) and overall survival (OS) was evaluated but also we addressed to the correlation between outcomes and DpR. ETS was defined as a reduction ≥ 20% of target lesions' diameters measured at 6 to 8 weeks from treatment start. DpR was percentage of maximal tumor shrinkage observed at the nadir diameter compared with baseline. Among 47 evaluable patients for the ETS, 12 (25.5%) patients experienced ETS. The ETS was significantly associated with better PFS (9.0 vs. 4.2 months) as well as OS (24.0 vs. 9.1 months); moreover, the association had a statistically significance for PFS but a strong trend for OS in multivariate analysis. The DpR was statistically significantly but weakly associated with OS. In conclusion, this is the first report that the early response to chemotherapy may predict favorable outcomes in patients with advanced pancreatic cancer treated with FOLFIRINOX therapy.

Efficacy of continued cetuximab for unresectable metastatic colorectal cancer after disease progression during first-line cetuximab-based chemotherapy: a retrospective cohort study

This study assessed second-line continued use of cetuximab for treatment of unresectable metastatic colorectal cancer (mCRC) after disease progression during first-line cetuximab-based therapy. Consecutive patients with wild-type KRAS exon 2 and unresectable mCRC were retrospectively enrolled after disease progression during first-line cetuximab-based chemotherapy. Second-line continued cetuximab plus changed chemotherapy (cetuximab continuation group, n = 102) was compared with changed chemotherapy only (chemotherapy only group, n = 96) with respect to treatment efficacy and safety endpoints. NRAS and other KRAS genotypes were also detected as a post hoc analysis. The cetuximab continuation group showed better progression-free survival (median, 6.3 vs. 4.5 months, P = 0.004), overall survival (median, 17.3 vs. 14.0 months, P < 0.001) and disease control rate (70.6% vs. 53.1%, P = 0.011), and a potentially better overall response rate (18.6% vs. 9.4%, P = 0.062) than the chemotherapy only group. These benefits were seen mainly in patients with all RAS wild-type and exhibiting first-line early tumor shrinkage (ETS). For patients with other RAS mutations or who did not achieve first-line ETS, there was no difference between the two groups. These findings suggest that for patients with all RAS wild-type and unresectable mCRC who had disease progression during first-line cetuximab-based treatment, second-line continued cetuximab is effective. Moreover, ETS during first-line cetuximab-based treatment may be predictive of the efficacy of second-line continued cetuximab.

Role of depth of response and MTHFR genotype as predictors of fluorouracil rechallenge therapy for refractory metastatic colorectal cancer

There is limited data on the clinical and biological parameters that enable the prediction of the benefits derived from additional chemotherapy after disease progression compared with standard chemotherapy in patients with metastatic colorectal cancer (mCRC). The present study evaluated the role of tumor response as a clinical parameter and single nucleotide polymorphisms (SNPs) as a biomarker to predict the benefit of additional 5-fluorouracil (5-FU) rechallenge chemotherapy in patients with refractory mCRC. Tumor responses were retrospectively reviewed based on the Response Evaluation Criteria in Solid Tumors, early tumor shrinkage (ETS) and depth of response (DoR) following first-line chemotherapy in patients with stage IV CRC. Together with these parameters, SNPs known to be associated with the response to chemotherapy were analyzed with survival outcomes. In total, the tumor responses of 242 patients with mCRC were evaluated. Overall response and ETS were identified in 110 (45.4%) and 103 patients (42.6%), respectively, and the median DoR was 38.5±30.08%. ETS and DoR were significantly associated with survival outcomes, including progression-free survival, post-progression survival and overall survival. Among these patients, SNPs were analyzed in 171 patients. X-ray repair cross complementing 1 (XRCC1) (AG/AA) with a DoR >60%, good performance status and the absence of bone lesions were associated with improved overall survival. In patients receiving third-line chemotherapy with 5-FU rechallenge therapy, the methylenetretrahydrofolate reductase (MTHFR) (C677T) CC genotype and a DoR >60% were significantly associated with a good prognosis in multivariate analysis. XRCC1 (AG/AA) was also associated with a good prognosis in patients with mCRC. Patients with a DoR >60% following first-line chemotherapy and a MTHFR (C677T) CC genotype exhibited a survival benefit from 5-FU retreatment. Therefore, the DoR and MTHFR genotype are potential markers for selecting patients with refractory mCRC that would benefit from 5-FU rechallenge therapy.

Relation of early tumor shrinkage (ETS) observed in first-line treatment to efficacy parameters of subsequent treatment in FIRE-3 (AIOKRK0306)

We explored the association of early tumor shrinkage (ETS) and non-ETS with efficacy of first-line and consecutive second-line treatment in patients with KRAS wild-type metastatic colorectal cancer treated in FIRE-3. Assessment of tumor shrinkage was based on the sum of longest diameters of target lesions, evaluated after 6 weeks of treatment. Shrinkage was classified as ETS (shrinkage by ≥ 20%), mETS (shrinkage by 0 to <20%), mPD (minor progression >0 to <20%) and PD (progression ≥20%). Overall survival (OS) was 33.2 (95% CI 28.0-38.4) months in ETS patients, while non-ETS was associated with less favorable outcome (mETS 24.0 (95% CI 21.2-26.9) months, mPD 19.0 (95% CI 13.0-25.0) months, PD 12.8 (95% CI 11.1-14.5) months). Differences in PFS of first-line therapy were less pronounced. ETS subgroups defined in first-line therapy also correlated with efficacy of second-line therapy. Progression-free survival in second-line (PFS2nd) was 6.5 months (5.8-7.2) for ETS, and was 5.6 (95% CI 4.7-6.5) months for mETS, 4.9 (95% CI 3.7-6.1) months for mPD and 3.3 (95% CI 2.3-4.3) months for PD. PFS of first-line and PFS2nd showed a linear correlation (Bravais-Pearson coefficient: 0.16, p = 0.006). While ETS is associated with the most favorable outcome, non-ETS represents a heterogeneous subgroup with distinct characteristics of less favorable initial tumor response to treatment. This is the first analysis to demonstrate that early tumor response observed during first-line FOLFIRI-based therapy may also relate to efficacy of second-line treatment. Early response parameters may serve as stratification factors in trials recruiting pretreated patients.

Timing and extent of response in colorectal cancer: critical review of current data and implication for future trials

The identification of new surrogate endpoints for advanced colorectal cancer is becoming crucial and, along with drug development, it represents a research field increasingly studied. Although overall survival (OS) remains the strongest trial endpoint available, it requires larger sample size and longer periods of time for an event to happen. Surrogate endpoints such as progression free survival (PFS) or response rate (RR) may overcome these issues but, as such, they need to be prospectively validated before replacing the real endpoints; moreover, they often bear many other limitations. In this narrative review we initially discuss the role of time-to-event endpoints, objective response and response rate as surrogates of OS in the advanced colorectal cancer setting, discussing also how such measures are influenced by the tumor assessment criteria currently employed. We then report recent data published about early tumor shrinkage and deepness of response, which have recently emerged as novel potential endpoint surrogates, discussing their strengths and weaknesses and providing a critical comment. Despite being very compelling, the role of such novel response measures is yet to be confirmed and their surrogacy with OS still needs to be further investigated within larger and well-designed trials.

Early tumor shrinkage and depth of response predict long-term outcome in metastatic colorectal cancer patients treated with first-line chemotherapy plus bevacizumab: results from phase III TRIBE trial by the Gruppo Oncologico del Nord Ovest

BACKGROUND

Early tumor shrinkage (ETS) and depth of response (DoR) predict overall survival (OS) in first-line trials of chemotherapy ± anti-EGFR monoclonal antibodies in metastatic colorectal cancer (mCRC). These associations and the predictive accuracy of response measurements for survival parameters were investigated in the phase III TRIBE trial of FOLFOXIRI plus bevacizumab (bev) versus FOLFIRI plus bev.

PATIENTS AND METHODS

A landmark approach was adopted to define the assessable population. The distribution of RECIST response rate, ETS and DoR was compared in the two arms. Associations between response measurements and progression-free survival (PFS), post-progression survival (PPS) and OS were tested by univariate and multivariate Cox models. Prediction performance of each factor was estimated by C-index.

RESULTS

A significantly higher percentage of patients in the FOLFOXIRI plus bev arm achieved ETS ≥20%, when compared with the control arm (62.7% versus 51.9%, P = 0.025). Also the DoR was significantly higher in the triplet plus bev arm (43.4% versus 37.8%, P = 0.003). Both ETS and DoR were associated with PFS, PPS and OS at the univariate analyses and in the multivariate models stratified for other prognostic variables. Both ETS and DoR were able to predict survival as accurately as RECIST response.

CONCLUSION

FOLFOXIRI plus bev improves ETS and DoR when compared with FOLFIRI plus bev. Achieving rapid and deep tumor shrinkage consistently delays tumor progression and prolongs survival in patients treated with first-line chemotherapy plus bev. ETS is a promising and valuable end point for clinical trials' design deserving further investigation.

Impact of early tumor shrinkage on clinical outcome in wild-type-KRAS colorectal liver metastases treated with cetuximab

BACKGROUND AND AIM

To evaluate the impact of early tumor shrinkage (ETS) on long-term outcome in patients with wild-type Kirsten rat sarcoma viral oncogene homolog (KRAS) unresectable colorectal liver metastases (CLM) receiving cetuximab plus chemotherapy.

METHODS

A total of 138 patients in a randomized controlled trial (70 in armA received cetuximab plus chemotherapy, 68 in armB received chemotherapy alone), as previously reported (Ye et al., 2013) were included into this analysis. The cut-off date updated for overall survival (OS) was June 2014. ETS was defined as a ≥ 20% reduction of the longest diameters of the target lesions compared with baseline at the first evaluation (8 weeks). Outcome measures were progression-free survival (PFS) and OS.

RESULTS

There were 132 patients available for evaluation, and ETS occurred more frequently in armA than that in armB (P = 0.003). ETS was associated with longer OS (armA: 35.7 vs. 19.5 months, P < 0.001; armB 28.7 vs. 18.7 months, P = 0.01) and PFS (armA: 13.4 vs. 4.2 months, P < 0.001; armB 7.0 vs. 4.2 months, P = 0.001) compared with patients with no-ETS. Among patients with ETS, there was a significant difference between armA and armB in PFS (P = 0.03), but not in OS (P = 0.19). All 23 patients who underwent liver surgery achieved ETS. In armA, for patients without liver surgery, patients observed ETS also gained an increased survival benefit over those no-ETS in OS (P = 0.02) and PFS (P < 0.001). ETS was an independent predictor of improved OS (hazard ratio 0.56, P = 0.007).

CONCLUSION

ETS may serve as a predictor of favorable outcome in patients with wild-type KRAS CLM receiving cetuximab plus chemotherapy.