The initial change in tumor size predicts response and survival in patients with metastatic colorectal cancer treated with combination chemotherapy

Optimizing the doses of cancer drugs after usual dose finding

Since the middle of the 20th century, oncology's dose-finding paradigm has been oriented toward identifying a drug's maximum tolerated dose, which is then carried forward into phase 2 and 3 trials and clinical practice. For most modern precision medicines, however, maximum tolerated dose is far greater than the minimum dose needed to achieve maximal benefit, leading to unnecessary side effects. Regulatory change may decrease maximum tolerated dose's predominance by enforcing dose optimization of new drugs. Dozens of already approved cancer drugs require re-evaluation, however, introducing a new methodologic and ethical challenge in cancer clinical trials. In this article, we assess the history and current landscape of cancer drug dose finding. We provide a set of strategic priorities for postapproval dose optimization trials of the future. We discuss ethical considerations for postapproval dose optimization trial design and review three major design strategies for these unique trials that would both adhere to ethical standards and benefit patients and funders. We close with a discussion of financial and reporting considerations in the realm of dose optimization. Taken together, we provide a comprehensive, bird's eye view of the postapproval dose optimization trial landscape and offer our thoughts on the next steps required of methodologies and regulatory and funding regimes.

Understanding the Interplay of CAR-NK Cells and Triple-Negative Breast Cancer: Insights from Computational Modeling

Chimeric antigen receptor (CAR)-engineered natural killer (NK) cells have recently emerged as a promising and safe alternative to CAR-T cells for targeting solid tumors. In the case of triple-negative breast cancer (TNBC), traditional cancer treatments and common immunotherapies have shown limited effectiveness. However, CAR-NK cells have been successfully employed to target epidermal growth factor receptor (EGFR) on TNBC cells, thereby enhancing the efficacy of immunotherapy. The effectiveness of CAR-NK-based immunotherapy is influenced by various factors, including the vaccination dose, vaccination pattern, and tumor immunosuppressive factors in the microenvironment. To gain insights into the dynamics and effects of CAR-NK-based immunotherapy, we propose a computational model based on experimental data and immunological theories. This model integrates an individual-based model that describes the interplay between the tumor and the immune system, along with an ordinary differential equation model that captures the variation of inflammatory cytokines. Computational results obtained from the proposed model shed light on the conditions necessary for initiating an effective anti-tumor response. Furthermore, global sensitivity analysis highlights the issue of low persistence of CAR-NK cells in vivo, which poses a significant challenge for the successful clinical application of these cells. Leveraging the model, we identify the optimal vaccination time, vaccination dose, and time interval between injections for maximizing therapeutic outcomes.

Progression-free survival, disease-free survival and other composite end points in oncology: improved reporting is needed

Composite outcome measures such as progression-free survival and disease-free survival are increasingly used as surrogate end points in oncology research, frequently serving as the primary end point of pivotal trials that form the basis for FDA and EMA approvals. Such outcome measures combine two or more distinct events (for example, tumour (re)growth, new lesions and/or death) into a single, time-to-event end point. The use of a composite end point can increase the statistical power of a clinical trial and decrease the follow-up period required to demonstrate efficacy, thus lowering costs; however, these end points have a number of limitations. Composite outcomes are often vaguely defined, with definitions that vary greatly between studies, complicating comparisons of results across trials. Altering the makeup of events included in a composite outcome can alter study conclusions, including whether treatment effects are statistically significant. Moreover, the events included in a composite outcome often vary in clinical significance, reflect distinct biological pathways and/or are affected differently by treatment. Therefore, knowing the precise breakdown of the component events is essential to accurately interpret trial results and gauge the true benefit of an intervention. In oncology clinical trials, however, such information is rarely provided. In this Perspective, we emphasize this deficiency through a review of 50 studies with progression-free survival as an outcome published in five top oncology journals, discuss the advantages and challenges of using composite end points, and highlight the need for transparent reporting of the component events.

Maintenance strategies after anti-EGFR-based induction in metastatic colorectal cancer: A systematic review and bayesian network meta-analysis

BACKGROUND

In RAS wild type (wt) metastatic colorectal cancer (mCRC) maintenance therapy after induction with fluoropyrimidine (FP)-based cytotoxic therapy (CT) plus anti-EGFR agents is controversial.

METHODS

Phase II-III randomized trials were included. Maintenance strategies considered were: observation, anti-EGFR or FP monotherapy, FP + anti-EGFR, doublet CT + anti-EGFR.

RESULTS

Maintenance with FP + anti-EGFR (HR 0.56, 95% CrI 0.36-0.89) showed the greatest PFS benefit compared to observation, ranking first on SUCRA analysis (96.4%). Considering OS, doublet CT+ anti-EGFR, FP + anti-EGFR and anti-EGFR monotherapy yielded similar results. For PFS, FP + anti-EGFR confirmed to be valuable in BRAF wt patients and left sided tumors. In left sided tumors, the OS benefit of adding CT was limited. FP plus anti-EGFR showed a favourable safety profile compared to doublet CT + anti-EGFR.

CONCLUSIONS

FP + anti-EGFR can be considered a valuable maintenance option in RAS wt mCRC. EGFR monotherapy can be considered, especially in left-sided tumors.

Improved survival outcome with not-delayed radiotherapy and immediate PD-1/PD-L1 inhibitor for non-small-cell lung cancer patients with brain metastases

PURPOSE

To investigate the impact of radiotherapy (RT) and immune checkpoint inhibitor (ICI) sequence on the survival outcome in NSCLC patients with brain metastasis, and decide the best time to initiate RT.

METHODS

Patients were managed with delayed RT (ICI delivered over 2 weeks prior to RT), concurrent RT (ICI delivered within 2 weeks prior to or after RT), or upfront RT (RT delivered over 2 weeks prior to ICI). Overall survival (OS), intracranial local progression-free survival (iLPFS), and intracranial distant progression-free survival (iDPFS) were assessed. A meta-analysis was performed to analyze the association between survival outcome and RT/ICI sequence.

RESULTS

A total of 73 NSCLC patients were identified with a median follow-up of 13.9 months. Patients who receive delayed RT demonstrated shorter iLPFS (P = 0.0029), iDPFS (P = 0.016), and OS (P < 0.001). A meta-analysis was conducted and a total of 4 studies, 254 patients were included. The HR was 0.44 for iDPFS (P = 0.03), 0.41 for OS (P < 0.01) when compared concurrent with delayed RT, 0.21 for iDPFS (P < 0.01), 0.32 for OS (P < 0.01) when compared upfront with delayed RT, consistent with our conclusion that delayed RT brought with worst iDPFS and OS. More importantly, the best overall response rate (BOR) decreased in cases with longer RT and ICI intervals. Patients who receive intervals of RT and ICI within 7 days achieve the best median BOR of - 53%.

CONCLUSIONS

Delayed RT brought poor survival outcomes including iLPFS, iDPFS, and OS in NSCLC patients. The shorter interval of RT and ICI is associated with better BOR.

Early evaluation of liver metastasis using spectral CT to predict outcome in patients with colorectal cancer treated with FOLFOXIRI and bevacizumab

PURPOSE

Early evaluation of the efficacy of first-line chemotherapy combined with bevacizumab in patients with colorectal cancer liver metastasis (CRLM) remains challenging. This study used 2-month post-chemotherapy spectral computed tomography (CT) to predict the overall survival (OS) and response of CRLM patients with bevacizumab-containing therapy.

METHOD

This retrospective analysis was performed in 104 patients with pathologically confirmed CRLM between April 2017 and October 2021. Patients were treated with 5-fluorouracil, leucovorin, oxaliplatin or irinotecan with bevacizumab. Portal venous phase spectral CT was performed on the target liver lesion within 2 months of commencing chemotherapy to demonstrate the iodine concentration (IoD) of the target liver lesion. The patients were classified as responders (R +) or non-responders (R -) according to the Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 at 6 months. Multivariate analysis was performed to determine the relationships of the spectral CT parameters, tumor markers, morphology of target lesions with OS and response. The differences in portal venous phase spectral CT parameters between the R + and R - groups were analyzed. Receiver operating characteristic (ROC) curves were used to evaluate the predictive power of spectral CT parameters.

RESULTS

Of the 104 patients (mean age ± standard deviation: 57.73 years ± 12.56; 60 men) evaluated, 28 (26.9%) were classified as R + . Cox multivariate analysis identified the iodine concentration (hazard ratio [HR]: 1.238; 95% confidence interval [95% CI]: 1.089-1.408; P < 0.001), baseline tumor longest diameter (BLD) (HR: 1.022; 95% CI: 1.005-1.038, P = 0.010), higher baseline CEA (HR: 1.670; 95% CI: 1.016-2.745, P = 0.043), K-RAS mutation (HR: 2.027; 95% CI: 1.192-3.449; P = 0.009), and metachronous liver metastasis (HR: 1.877; 95% CI: 1.179-2.988; P = 0.008) as independent risk factors for patient OS. Logistic multivariate analysis identified the IoD (Odds Ratio [OR]: 2.243; 95% CI: 1.405-4.098; P = 0.002) and clinical N stage of the primary tumor (OR: 4.998; 95% CI: 1.210-25.345; P = 0.035) as independent predictor of R + . Using IoD cutoff values of 4.75 (100ug/cm³) the area under the ROC curve was 0.916, sensitivity and specificity were 80.3% and 96.4%, respectively.

CONCLUSIONS

Spectral CT IoD can predict the OS and response of patients with CRLM after 2 months of treatment with bevacizumab-containing therapy.

Standard diametric versus volumetric early tumor shrinkage as a predictor of survival in metastatic colorectal cancer: subgroup findings of the randomized, open-label phase III trial FIRE-3 / AIO KRK-0306

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.

Patient perspectives on window of opportunity clinical trials in early-stage breast cancer

PURPOSE

Window of opportunity trials (WOT) are increasingly common in oncology research. In WOT participants receive a drug between diagnosis and anti-cancer treatment, usually for the purpose of investigating that drugs effect on cancer biology. This qualitative study aimed to understand patient perspectives on WOT.

METHODS

We recruited adults diagnosed with early-stage breast cancer awaiting definitive therapy at a single-academic medical center to participate in semi-structured interviews. Thematic and content analyses were performed to identify attitudes and factors that would influence decisions about WOT participation.

RESULTS

We interviewed 25 women diagnosed with early-stage breast cancer. The most common positive attitudes toward trial participation were a desire to contribute to research and a hope for personal benefit, while the most common concerns were the potential for side effects and how they might impact fitness for planned treatment. Participants indicated family would be an important normative factor in decision-making and, during the COVID-19 pandemic, deemed the absence of family members during clinic visits a barrier to enrollment. Factors that could hinder participation included delay in standard treatment and the requirement for additional visits or procedures. Ultimately, most interviewees stated they would participate in a WOT if offered (N = 17/25).

CONCLUSION

In this qualitative study, interviewees weighed altruism and hypothetical personal benefit against the possibility of side effect from a WOT. In-person family presence during trial discussion, challenging during COVID-19, was important for many. Our results may inform trial design and communication approaches in future window of opportunity efforts.

Twenty Years On: RECIST as a Biomarker of Response in Solid Tumours an EORTC Imaging Group - ESOI Joint Paper

Response evaluation criteria in solid tumours (RECIST) v1.1 are currently the reference standard for evaluating efficacy of therapies in patients with solid tumours who are included in clinical trials, and they are widely used and accepted by regulatory agencies. This expert statement discusses the principles underlying RECIST, as well as their reproducibility and limitations. While the RECIST framework may not be perfect, the scientific bases for the anticancer drugs that have been approved using a RECIST-based surrogate endpoint remain valid. Importantly, changes in measurement have to meet thresholds defined by RECIST for response classification within thus partly circumventing the problems of measurement variability. The RECIST framework also applies to clinical patients in individual settings even though the relationship between tumour size changes and outcome from cohort studies is not necessarily translatable to individual cases. As reproducibility of RECIST measurements is impacted by reader experience, choice of target lesions and detection/interpretation of new lesions, it can result in patients changing response categories when measurements are near threshold values or if new lesions are missed or incorrectly interpreted. There are several situations where RECIST will fail to evaluate treatment-induced changes correctly; knowledge and understanding of these is crucial for correct interpretation. Also, some patterns of response/progression cannot be correctly documented by RECIST, particularly in relation to organ-site (e.g. bone without associated soft-tissue lesion) and treatment type (e.g. focal therapies). These require specialist reader experience and communication with oncologists to determine the actual impact of the therapy and best evaluation strategy. In such situations, alternative imaging markers for tumour response may be used but the sources of variability of individual imaging techniques need to be known and accounted for. Communication between imaging experts and oncologists regarding the level of confidence in a biomarker is essential for the correct interpretation of a biomarker and its application to clinical decision-making. Though measurement automation is desirable and potentially reduces the variability of results, associated technical difficulties must be overcome, and human adjudications may be required.

Incorporating external data into the analysis of clinical trials via Bayesian additive regression trees

Most clinical trials involve the comparison of a new treatment to a control arm (eg, the standard of care) and the estimation of a treatment effect. External data, including historical clinical trial data and real-world observational data, are commonly available for the control arm. With proper statistical adjustments, borrowing information from external data can potentially reduce the mean squared errors of treatment effect estimates and increase the power of detecting a meaningful treatment effect. In this article, we propose to use Bayesian additive regression trees (BART) for incorporating external data into the analysis of clinical trials, with a specific goal of estimating the conditional or population average treatment effect. BART naturally adjusts for patient-level covariates and captures potentially heterogeneous treatment effects across different data sources, achieving flexible borrowing. Simulation studies demonstrate that BART maintains desirable and robust performance across a variety of scenarios and compares favorably to alternatives. We illustrate the proposed method with an acupuncture trial and a colorectal cancer trial.

Reproducibility and prognostic significance of area of residual tumor (ART) in post-neoadjuvant resections of pancreatic ductal adenocarcinoma

BACKGROUND

The pathologic assessments of tumor response after neoadjuvant chemoradiotherapy (NACRT) are critical to improving the prognostic stratification for patients with pancreatic ductal adenocarcinoma (PDAC). Here we clarified the utility of our new grading system based on the area of residual tumor (ART) as compared to existing systems, such as the College of American Pathologists (CAP) and MD Anderson (MDA) score.

METHODS

Eight reviewers individually evaluated the tumor regression grade of 30 patients with PDAC based on three types of grading systems. The interobserver concordance and clinicopathological characteristics were compared between the three systems.

RESULTS

The interobserver concordance (kappa value) of the ART, CAP, and MDA score were 0.61, 0.48, and 0.53, respectively. Discrepant cases, which were 27% of the cases, exhibited smaller tumor and tumor bed sizes than concordant cases. The reduction in tumor size evaluated by microscopy showed a correlation with the rate of change in carcinoembryonic antigen (CEA) level, CA19-9 level, and tumor size on computed tomography (CT). The ART score was correlated with the tumor size on CT before and after NACRT and disease-free survival. The CAP and MDA scores were not associated with prognosis.

CONCLUSION

The ART grading system may be the most practical system to assess the tumor response in post-NACRT resections of PDAC.

Modeling tumor measurement data to predict overall survival (OS) in cancer clinical trials

Introduction

Longitudinal tumor measurements (TM) are commonly recorded in cancer clinical trials of solid tumors. To define patient response to treatment, the Response Evaluation Criteria in Solid Tumors (RECIST) categorizes the otherwise continuous measurements, which results in substantial information loss. We investigated two modeling approaches to incorporate all available cycle-by-cycle (continuous) TM to predict overall survival (OS) and compare the predictive accuracy of these two approaches to RECIST.

Material and methods

Joint modeling (JM) for longitudinal TM and OS and two-stage modeling with potential time-varying coefficients were utilized to predict OS using data from three trials with cycle-by-cycle TM. The JM approach incorporates TM data collected throughout the course of the clinical trial. The two-stage modeling approach incorporates information from early assessments (before 12 weeks) to predict subsequent OS outcome. The predictive accuracy was quantified by c-indices.

Results

Data from 577, 337, and 126 patients were included for the analysis (from two stage IV colorectal cancer trials (N9741, N9841) and an advanced non-small cell lung cancer trial (N0026), respectively). Both the JM and two-stage modeling reached a similar conclusion, i.e. the baseline covariates (age, gender, and race) were mostly not predictive of OS (p-value > 0.05). Quantities derived from TM were strong predictors of OS in the two colorectal cancer trials (p < 0.001 for both association in JM and two-stage modeling parameters); but less so in the lung cancer trial (p = 0.053 for association in JM and p = 0.024 and 0.160 for two-stage modeling parameters). The c-indices from the two-stage modeling were higher than those from a model using RECIST (range: 0.611–0.633 versus 0.586–0.590). The dynamic c-indices from the JM were in the range of 0.627–0.683 indicating good predictive accuracy.

Conclusion

Both modeling approaches provide highly interpretable and clinical meaningful results; the improved predictive performance compared with RECIST indicates the possibility of deriving better trial endpoints from these approaches.

•

Two-stage modeling incorporating time-varying coefficients achieves better predictive accuracy than RECIST-alone.

•

Two–stage modeling offers the possibility of alternative endpoint definition.

•

Serial tumor measurements can be incorporated in OS prediction using joint modeling.

•

Joint modeling can potentially guide individualized medicine.

Influence of CDK5 Regulatory Subunit-Associated Protein 1-Like 1 Expression on the Survival of Patients with Non-Metastatic Nasopharyngeal Carcinoma

Background

The aim of this study was to investigate the influence of CDK5 regulatory subunit-associated protein 1-like 1 (CDKAL1) expression on the survival of nasopharyngeal carcinoma (NPC) patients.

Methods

A total of 140 non-metastatic NPC patients were retrospectively analyzed. The expression of CDKAL1 was detected by immunohistochemistry.

Results

The CDKAL1-negative group exhibited better overall survival (OS) according to Kaplan–Meier curve analysis (p = 0.006), with 5-year OS rates for the CDKAL1-negative and -positive groups of 89.7% and 70.2%, respectively. The CDKAL1-negative group also exhibited a tendency toward a better progression-free survival (PFS) rate. Multivariate analysis showed that CDKAL1 expression was independently associated with both OS (p = 0.002) and PFS (p = 0.043).

Conclusion

CDKAL1 expression is an independent negative predictor of patient survival in non-metastatic NPC.

Tumor Growth Rate to Predict the Outcome of Patients with Neuroendocrine Tumors: Performance and Sources of Variability

INTRODUCTION

Tumor growth rate (TGR), percentage of change in tumor volume/month, has been previously identified as an early radiological biomarker for treatment monitoring in neuroendocrine tumor (NET) patients. We assessed the performance and reproducibility of TGR at 3 months (TGR3m) as a predictor factor of progression-free survival (PFS), including the impact of imaging method and reader variability.

METHODS

Baseline and 3-month (±1 month) CT/MRI images from patients with advanced, grade 1-2 NETs were retrospectively reviewed by 2 readers. Influence of number of targets, tumor burden, and location of lesion on the performance of TGR3m to predict PFS was assessed by uni/multivariable Cox regression analysis. Agreement between readers was assessed by Lin's concordance coefficient (LCC) and kappa coefficient (KC).

RESULTS

A total of 790 lesions were measured in 222 patients. Median PFS was 22.9 months. On univariable analysis, number of lesions (</≥4), tumor burden, and presence of liver metastases were significantly correlated with PFS. On multivariate analysis, ≥4 lesions (HR: 1.89 [95% CI: 1.01-3.57]), TGR3m ≥0.8%/month (HR: 4.01 [95% CI: 2.31-6.97]), and watch and wait correlated with shorter PFS. No correlation was found between TGR3m and number of lesions (rho: -0.2; p value: 0.1930). No difference in mean TGR3m across organs was shown (p value: 0.6). Concordance between readers was acceptable (LCC: 0.52 [95% CI: 0.38-0.65]; KC: 0.57, agreement: 81.55%). TGR3m remained a significant prognostic factor when data from the second reader were employed (HR: 4.35 [95% CI: 2.44-7.79]; p value <0.001) regardless his expertise (HR: 1.21 [95% CI: 0.70-2.09]; p value: 0.493).

DISCUSSION/CONCLUSION

TGR3m is a robust and early radiological biomarker able to predict PFS. It may be used to identify patients with advanced NETs who require closer radiological follow-up.

Effect of early tumor response on the health-related quality of life among patients on second-line chemotherapy for advanced gastric cancer in the ABSOLUTE trial

BACKGROUND

This study evaluated the association between early tumor response at 8 weeks, previously reported as a positive outcome prognosticator, and health-related quality of life (HRQOL) in advanced gastric cancer (AGC) patients enrolled in the ABSOLUTE trial.

METHODS

HRQOL was assessed using the EuroQol-5 Dimension (EQ-5D) utility index score in patients with complete response (CR) + partial response (PR) and progressive disease (PD) at 8 weeks, and time-to-deterioration (TtD) of the EQ-5D score, with the preset minimally important difference (MID) of 0.05, was compared between these populations. Among the enrolled patients, 143 and 160 patients were assessable in weekly solvent-based paclitaxel (Sb-PTX) arm and weekly nanoparticle albumin-bound paclitaxel (nab-PTX) arm, respectively.

RESULTS

Changes of the EQ-5D score from baseline to 8 weeks in the nab-PTX arm were 0.0009 and - 0.1229 in CR + PR and PD patients, respectively; the corresponding values for the Sb-PTX arm were - 0.0019 and - 0.1549. For both treatments, changes of the EQ-5D score from baseline at 8 weeks were significantly larger in patients with PD than in those with CR + PR. The median TtD was 3.9 and 2.2 months in patients with CR + PR and PD, respectively, for nab-PTX [hazard ratio (HR) = 0.595, 95% confidence interval (CI) 0.358-0.989]. For Sb-PTX, the corresponding values were 4.7 and 2.0 months (HR = 0.494, 95% CI 0.291-0.841).

CONCLUSIONS

Early tumor shrinkage was associated with maintained HRQOL in AGC patients on the second-line chemotherapy with taxanes.

Associations of baseline patient-reported outcomes with treatment outcomes in advanced gastrointestinal cancer

BACKGROUND

Patient-reported outcomes (PROs) assessing quality of life (QOL) and symptom burden correlate with clinical outcomes in patients with cancer. However, to the authors' knowledge, data regarding associations between PROs and treatment response are lacking.

METHODS

The authors prospectively approached consecutive patients with advanced gastrointestinal cancer who were initiating a new treatment. Prior to treatment, patients reported their QOL (Functional Assessment of Cancer Therapy-General [FACT-G], 4 subscales: Functional, Physical, Emotional, Social; higher scores indicate better QOL) and symptom burden (Edmonton Symptom Assessment System [ESAS], Patient Health Questionnaire-4 [PHQ-4]; higher scores represent greater symptoms). Regression models were used to examine associations of baseline PROs with treatment response (clinical benefit or progressive disease [PD] at time of first scan), healthcare utilization, and survival.

RESULTS

From May 2019 to April 2020, a total of 112 patients with advanced gastrointestinal cancer were enrolled. For treatment response, 64.3% had CB and 35.7% had PD. Higher baseline ESAS-Physical (odds ratio, 1.04; P = .027) and lower FACT-G Functional (odds ratio, 0.92; P = .038) scores were associated with PD. Higher ESAS-Physical (hazard ratio [HR], 1.03; P = .044) and lower FACT-G Total (HR, 0.96; P = .005), FACT-G Physical (HR, 0.89; P < .001), and FACT-G Functional (HR, 0.87; P < .001) scores were associated with a greater hospitalization risk. Lower FACT-G Total (HR, 0.96; P = .009) and FACT-G Emotional (HR, 0.86; P = .012) scores as well as higher ESAS-Total (HR, 1.03; P = .014) and ESAS-Physical (HR, 1.04; P = .032) scores were associated with worse survival.

CONCLUSIONS

Baseline PROs are associated with treatment response in patients with advanced gastrointestinal cancer, namely physical symptoms and functional QOL, in addition to health care use and survival. The findings of the current study support the association between PROs and important clinical outcomes, including the novel finding of treatment response.

Establishment of prognostic nomogram for elderly colorectal cancer patients: a SEER database analysis

Background

This study aimed to establish nomogram models of overall survival (OS) and cancer-specific survival (CSS) in elderly colorectal cancer (ECRC) patients (Age ≥ 70).

Methods

The clinical variables of patients confirmed as ECRC between 2004 and 2016 were retrieved from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate analysis were performed, followed by the construction of nomograms in OS and CSS.

Results

A total of 44,761 cases were finally included in this study. Both C-index and calibration plots indicated noticeable performance of newly established nomograms. Moreover, nomograms also showed higher outcomes of decision curve analysis (DCA) and the area under the curve (AUC) compared to American Joint Committee on Cancer (AJCC) tumor-node-metastasis (TNM) stage and SEER stage.

Conclusions

This study established nomograms of elderly colorectal cancer patients with distinct clinical values compared to AJCC TNM and SEER stages regarding both OS and CSS.

Radiological Response Heterogeneity Is of Prognostic Significance in Metastatic Renal Cell Carcinoma Treated with Vascular Endothelial Growth Factor-targeted Therapy

BACKGROUND

Response evaluation criteria in solid tumours (RECIST) is widely used to assess tumour response but is limited by not considering disease site or radiological heterogeneity (RH).

OBJECTIVE

To determine whether RH or disease site has prognostic significance in patients with metastatic clear-cell renal cell carcinoma (ccRCC).

DESIGN, SETTING, AND PARTICIPANTS

A retrospective analysis was conducted of a second-line phase II study in patients with metastatic ccRCC (NCT00942877), evaluating 138 patients with 458 baseline lesions.

INTERVENTION

The phase II trial assessed vascular endothelial growth factor-targeted therapy±Src inhibition.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

RH at week 8 was assessed within individual patients with two or more lesions to predict overall survival (OS) using Kaplan-Meier method and Cox regression model. We defined a high heterogeneous response as occurring when one or more lesion underwent a ≥10% reduction and one or more lesion underwent a ≥10% increase in size. Disease progression was defined by RECIST 1.1 criteria.

RESULTS AND LIMITATIONS

In patients with a complete/partial response or stable disease by RECIST 1.1 and two or more lesions at week 8, those with a high heterogeneous response had a shorter OS compared to those with a homogeneous response (hazard ratio [HR] 2.01; 95% confidence interval [CI]: 1.39-2.92; p<0.001). Response by disease site at week 8 did not affect OS. At disease progression, one or more new lesion was associated with worse survival compared with >20% increase in sum of target lesion diameters only (HR 2.12; 95% CI: 1.43-3.14; p<0.001). Limitations include retrospective study design.

CONCLUSIONS

RH and the development of new lesions may predict survival in metastatic ccRCC. Further prospective studies are required.

PATIENT SUMMARY

We looked at individual metastases in patients with kidney cancer and showed that a variable response to treatment and the appearance of new metastases may be associated with worse survival. Further studies are required to confirm these findings.

Missing tumor measurement (TM) data in the search for alternative TM-based endpoints in cancer clinical trials

PURPOSE

Missing data commonly occur in cancer clinical trials (CCT) and may hinder the search for alternative trial endpoints. We consider reasons for missing tumor measurement (TM) data in CCT and how missing TM data are typically handled. We explore the potential impact of missing TM data on predictive ability of a set of TM-based endpoints.

METHODS

Literature review identifies reasons for and approaches to handling missing TM data. Data from 3 actual clinical trials were used for illustration. A sensitivity analysis of the potential impact of missing TM data was performed by comparing overall survival (OS) predictive ability of alternative endpoints using observed and imputed data.

RESULTS

Reasons for missing TM data in CCT are presented, based on the literature review and the three trials. Although missing TM data impacted individual objective status (e.g. 12-week status changed for 53% of patients in one imputation set), it surprisingly only minimally impacted endpoint predictive ability (e.g. median c-indices of 500 imputed datasets ranged from 0.566 to 0.570 for N9741, 0.592-0.616 for N9841, and 0.542-0.624 for N0026).

CONCLUSION

By understanding the reasons for missingness, we can better anticipate them and minimize their occurrence. Our preliminary analysis suggests missing TM data may not impact endpoint predictive ability, but could impact objective response status classification; however these findings require further validation. With response status accepted as an important phase II endpoint in the development of new cancer therapies (including immunotherapy), we urge that in CCT complete TM data collection and adherence to protocol-defined disease evaluation as closely as possible be a priority.

A semi-automated technique for adenoma quantification in the ApcMin mouse using FeatureCounter

Colorectal cancer is a major contributor to death and disease worldwide. The Apc^Min mouse is a widely used model of intestinal neoplasia, as it carries a mutation also found in human colorectal cancers. However, the method most commonly used to quantify tumour burden in these mice is manual adenoma counting, which is time consuming and poorly suited to standardization across different laboratories. We describe a method to produce suitable photographs of the small intestine of Apc^Min mice, process them with an ImageJ macro, FeatureCounter, which automatically locates image features potentially corresponding to adenomas, and a machine learning pipeline to identify and quantify them. Compared to a manual method, the specificity (or True Negative Rate, TNR) and sensitivity (or True Positive Rate, TPR) of this method in detecting adenomas are similarly high at about 80% and 87%, respectively. Importantly, total adenoma area measures derived from the automatically-called tumours were just as capable of distinguishing high-burden from low-burden mice as those established manually. Overall, our strategy is quicker, helps control experimenter bias, and yields a greater wealth of information about each tumour, thus providing a convenient route to getting consistent and reliable results from a study.

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.

Prognostic Impact of the Components of Progressive Disease on Survival After First-Line Tyrosine Kinase Inhibitor Therapy for Metastatic Renal Cell Carcinoma

BACKGROUND

According to the Response Evaluation Criteria in Solid Tumors (RECIST) classification, progressive disease (PD) is defined as target lesion growth (TLG), unequivocal non-target lesion growth (NTLG), or new lesion appearance (NLA). The prognostic impact of the components of PD in tyrosine kinase inhibitor (TKI) therapy for metastatic renal cell carcinoma (mRCC) remains unknown.

OBJECTIVE

We retrospectively evaluated the prognostic impact of these PD components on survival in patients with mRCC after first-line TKI therapy.

PATIENTS AND METHODS

Patients were divided into three groups (TLG, NTLG, and NLA) based on the components of PD. Progression-free survival (PFS) and overall survival (OS) after first-line TKI therapy were compared between groups using the Kaplan-Meier method and log-rank test. The predictive impact of the PD components was evaluated using multivariate analyses.

RESULTS

Among the 116 patients included, 80 (69.0%) had TLG, 18 (15.5%) NTLG, and 69 (58.6%) NLA. The mean PFS and OS were shorter for patients with TLG than those without TLG (PFS, 7.1 vs. 11.6 months, p = 0.0071; OS, 18.2 vs. 25.5 months, p = 0.0091). TLG was an independent predictor of PFS (hazard ratio [HR], 1.59; 95% confidence interval [CI], 1.02-2.51; p = 0.0395) and OS (HR, 1.67; 95% CI, 1.02-2.83; p = 0.040). NTLG and NLA were not associated with survival.

CONCLUSIONS

In this retrospective single-center study, patients with TLG had poor survival after first-line TKI therapy for mRCC. Thus, individual components of PD influence patient prognosis.

Using plasma cell-free DNA to monitor the chemoradiotherapy course of cervical cancer

The liquid biopsy is being integrated into cancer diagnostics and surveillance. However, critical questions still remain, such as how to precisely evaluate cancer mutation burden and interpret the corresponding clinical implications. Herein, we evaluated the role of peripheral blood cell-free DNA (cfDNA) in characterizing the dynamic mutation alterations of 48 cancer driver genes from cervical cancer patients. We performed targeted deep sequencing on 93 plasma cfDNA from 57 cervical cancer patients and from this developed an algorithm, allele fraction deviation (AFD), to monitor in an unbiased manner the dynamic changes of genomic aberrations. Differing treatments, including chemotherapy (n = 22), radiotherapy (n = 14) and surgery (n = 15), led to a significant decrease in AFD values (Wilcoxon, p = 0.029). The decrease of cfDNA AFD values was accompanied by shrinkage in the size of the tumor in most patients. However, in a subgroup of patients where cfDNA AFD values did not reflect a reduction in tumor size, there was a detection of progressive disease (metastasis). Furthermore, a low AFD value at diagnosis followed a later increase of AFD value also successfully predicted relapse. These results show that plasma cfDNA, together with targeted deep sequencing, may help predict treatment response and disease development in cervical cancer.

Optimizing sequential treatment with anti-EGFR and VEGF mAb in metastatic colorectal cancer: current results and controversies

Anti-EGFR mAb (cetuximab or panitumumab) and anti-VEGF mAb (bevacizumab) are the two main targeted agents available for RAS wild-type (WT) metastatic colorectal cancer (mCRC) treatment. Nonetheless, three head-to-head clinical trials evaluating anti-EGFR mAb vs -VEGF mAb in first-line treatment failed to conclude a uniform result. Recently, a few small clinical studies revealed that prior use of bevacizumab may impair the effect of cetuximab or panitumumab. Preclinical studies have also suggested that pretreatment with bevacizumab may lead to simultaneous resistance to anti-EGFR mAb. Therefore, we performed this review to summarize the available data regarding the optimal sequential treatment of anti-EGFR and -VEGF mAb for RAS or KRAS WT mCRC and discuss the potential mechanisms that may explain this phenomenon. Primary tumor location and early tumor shrinkage have emerged as new potential prognostic and predictive factors in mCRC. We also collected information to explore whether these factors affect the optimal sequencing of targeted therapy in mCRC. However, definite conclusions cannot be made, and we can only speculate on optimal treatment recommendations based on the contradictory results.

Are tumor size changes predictive of survival for checkpoint blockade based immunotherapy in metastatic melanoma?

BACKGROUND

In oncology clinical development, objective response rate, disease control rate and early tumor size changes are commonly used as efficacy metrics for early decision-making. However, for immunotherapy trials, it is unclear whether these early efficacy metrics are still predictive of long-term clinical benefit such as overall survival. The goal of this paper is to identify appropriate early efficacy metrics predictive of overall survival for immunotherapy trials.

METHODS

Based on several checkpoint blockade based immunotherapy studies in metastatic melanoma, we evaluated the predictive value of early tumor size changes and RECIST-based efficacy metrics at various time points on overall survival. The cut-off values for tumor size changes to predict survival were explored via tree based recursive partitioning and validated by external data. Sensitivity analyses were performed for the cut-offs.

RESULTS

The continuous tumor size change metric and RECIST-based trichotomized response metric at different landmark time points were found to be statistically significantly associated with overall survival. The predictive values were higher at Week 12 and 18 than those at Week 24. The percentage of tumor size changes appeared to have comparable or lower predictive values than the RECIST-based trichotomized metric, and a cut-off of approximately 10% tumor reduction appeared to be reasonable for predicting survival.

CONCLUSIONS

An approximate 10% tumor reduction may be a reasonable cut-off for early decision-making while the RECIST-based efficacy metric remains the primary tool. Early landmark analysis is especially useful for decision making when accrual is fast. Composite response rate (utilizing different weights for PR/CR and SD) may be worth further investigation.

TRIAL REGISTRATION

Clinical trials gov, NCT01295827 , Registered February 15, 2011; NCT01704287 , Registered October 11, 2012; NCT01866319 , Registered May 31, 2013.

Early tumor shrinkage after first-line medical treatment of metastatic colorectal cancer: a meta-analysis

BACKGROUND

Early tumor shrinkage (ETS) is a response-related endpoint of clinical trials of chemotherapy (CHT) of patients with metastatic colorectal cancer (mCRC). It identifies a dimensional reduction of tumor size by at least 20-30% after 6-8 weeks of CHT.

METHODS

A literature search of randomized trials of systemic treatment including CHT with or without antiangiogenics or anti-EGFR inhibitors in patients with mCRC has been conducted, and studies reporting the results of the relationship of ETS with overall survival (OS) and progression-free survival (PFS) were selected.

RESULTS

Twelve trials, including 3117 patients, have been included; all data were retrospective and only 72% of the enrolled patients have been evaluated for ETS. Two meta-analyses, each including 20 study cohorts from the selected 12 trials, reported a strong relationship of ETS with OS (HR 0.62; CIs 0.55-0.69) and of ETS with PFS (HR 0.66; CIs 0.60-0.73). However, both meta-analyses displayed a high level of heterogeneity. Among nine possible moderators, three variables (median age, surgery of metastases, and publication year) were able to explain at least a part of this heterogeneity.

CONCLUSION

ETS is a simple and interesting intermediate endpoint for clinical practice and future trials of medical treatments of patients with mCRC, but a large prospective analysis and validation are mandatory.

Tumor-size responses to first-line is a predictor of overall survival in metastatic colorectal cancer

OBJECTIVES

Early tumor shrinkage (ETS) has been reported to be associated with survival of metastatic colorectal cancer (mCRC) patients. Our aim was to analyze long-term tumor-size evolution, according to early mCRC best responses during the first-line therapy, to evaluate first best response-survival links.

METHODS

Sixty-five patients with unresectable mCRCs, treated between 2010 and 2015, were included retrospectively in this descriptive monocenter study and grouped according to their RECIST 1.1 first-line best responses: progressive disease (PD_fl), stable disease with tumor-size evolution between 0 and + 19% (SD_fl+) or 0 and - 29% (SD_fl-), and partial responders (PRs), who were classed PR with ETS (ETS_fl) or without (PR_fl). Tumor-size evolution and best tumor responses to each chemotherapy line were analyzed.

RESULTS

Tumor loads of ETS_fl or PR_fl mCRCs tended to remain inferior to their initial values: 60% of patients died with target lesion sums below baseline. For first-line SD_fl+ or PD_fl mCRCs, rapid tumor load increases continued during successive lines: > 80% died with target lesion sums above baseline. ETS_fl mCRCs responded better to subsequent lines (37.5% second-line PR), whereas PD_fl mCRCs remained refractory to other therapies (0% second- and third-line PR). Overall survival rates were significantly (p = 0.03) longer for the ETS_fl group (29.9 [95% CI: 12.6-47.1] months) and shorter for the PD_fl group (17.1 [95% CI: 1.5-37.5] months).

CONCLUSION

Tumors responding to first-line chemotherapy also responded better to subsequent lines, whereas PD_fl mCRCs remained refractory, which may explain the better survival associated with ETS_fl.

KEY POINTS

• Early shrinking tumors under first-line chemotherapy responded better to subsequent lines, maintaining low tumor loads, potentially explaining the link between early tumor shrinkage and overall survival of metastatic colorectal cancer (mCRC) patients. • mCRCs progressing under first-line chemotherapy remained refractory to other therapies and their tumor loads increased rapidly. • Even outside a clinical trial, an early first CT scan reevaluation with RECIST criteria 8 weeks after starting first-line therapy is crucial to determine long-term mCRC evolution.

Impact of the occurrence of new lesions on the survival of patients who undergo chemotherapy for metastatic colorectal cancer

In clinical practice, the efficacy of chemotherapy for metastatic colorectal cancer (mCRC) is typically evaluated according to the Response Evaluation Criteria in Solid Tumours (RECIST) criteria, and an appropriate treatment plan is determined. In the case of progressive disease (PD), the components of the treatment are altered; however, PD, as defined by the RECIST criteria, includes various types of progression. While detailed consideration regarding the impact of the growth pattern of measurable target lesions on survival has been performed, the impact of the occurrence of new lesions on survival is unclear. The aim of the present study was to assess the impact of the occurrence of new lesions on the survival of patients who underwent chemotherapy for mCRC. Among the patients who received doublet chemotherapy for mCRC as a first-line treatment between 2008 and 2016, 81, who stopped the chemotherapy due to PD, were enrolled in the present study. The types of progression were classified according to the definitions of RECIST. Subsequently, the following criteria were considered: The growth of measurable target lesions, the occurrence of new lesions and the unequivocal progression of non-target disease. Furthermore, the developing patterns of new lesions were also assessed. The association between the type of progression and the survival after the failure of the first-line chemotherapy was explored. Forty (49.4%) patients only experienced growth of measurable target lesions, 41 (50.6%) of the patients had new lesions and 3 (3.7%) of the patients had unequivocal progression of non-target disease. The survival rate from the discontinuation of first-line chemotherapy in patients with new lesions was significantly worse than that in patients without new lesions (P=0.0068); however, the developing patterns of new lesions were not associated with survival. Regardless of the developing patterns of new lesions, patients who stopped chemotherapy due to new lesions had worse survival rates from the discontinuation of first-line chemotherapy compared with those who stopped chemotherapy due only to the growth of measurable target lesions. Because the occurrence of new lesions represents severe progressive disease, patients with new lesions may require more intensive chemotherapy. The type of progression may be useful information for selecting the appropriate treatment following the failure of first-line chemotherapy.

Early tumor shrinkage and depth of response in patients with advanced gastric cancer: a retrospective analysis of a randomized phase III study of first-line S-1 plus oxaliplatin vs. S-1 plus cisplatin

BACKGROUND

We investigated early tumor shrinkage (ETS) and depth of response (DpR) using data from the G-SOX study comparing S-1 plus oxaliplatin with S-1 plus cisplatin as the first-line treatment for advanced gastric cancer (AGC).

METHODS

ETS was determined as % decrease in the sum of the longest diameters of the target lesions at the first evaluation of week 6 compared to baseline. DpR was the maximum % shrinkage during the study treatment. The impact of ETS (cutoff value 20%) and DpR (continuous value) on progression-free survival (PFS) and overall survival (OS) were assessed by the log-rank test and Cox regression analysis including prognostic factors obtained in the G-SOX study; ECOG performance status, baseline sum of tumor diameters, disease status (recurrent/unresectable), and histology (diffuse/intestinal).

RESULTS

Among 685 patients enrolled in the G-SOX study, 632 patients who had the first tumor evaluation were analyzed. Patients with ETS ≥ 20% had longer PFS (median 4.5 vs. 2.8 months, p < 0.0001) and OS (median 14.8 vs. 10.5 months, p < 0.0001) than those with ETS < 20%. Adjusted hazard ratios of ETS < 20 vs. ≥ 20% were 0.606 (95% confidence interval (CI) 0.506-0.725) for PFS and 0.589 (95% CI 0.492-0.704) for OS. DpR was also significantly associated with PFS and OS (both p < 0.0001). These results were similar between the SOX and CS groups.

CONCLUSIONS

In AGC patients receiving the first-line therapy, ETS and DpR might be predictors for PFS and OS.

The mode of progressive disease affects the prognosis of patients with metastatic breast cancer

Background

According to the Response Evaluation Criteria in Solid Tumors (RECIST), progressive disease (PD) is diagnosed under two conditions: an increase in size of pre-existing lesions (IS) and the appearance of new lesions (NL). We retrospectively investigated the difference in the prognosis between IS and NL.

Methods

Patients receiving drug therapies for metastatic breast cancer between 2004 and 2015 at our institution were reviewed. The survival time after NL and IS was compared and the frequency of NL with each drug calculated.

Results

For the 107 eligible patients, the survival time after NL at second-line chemotherapy was significantly worse than after IS (median survival time 4.3 months vs. 20.3 months, p = 0.0048). Maintenance therapy with bevacizumab or trastuzumab had a high frequency of NL (88.9%), and third-line eribulin had a low frequency of NL (16.7%). A multivariate analysis showed that NL at second-line chemotherapy was not an independent risk factor (hazard ratio 1.02, 95%; confidence interval 0.54–1.93, p = 0.95) for the total survival time.

Conclusions

Patients with IS had a better survival after PD than those with NL. We may be able to avoid changing drug therapy for patients without NL and allow them to continue drug therapy for longer.

Quantitative imaging features of pretreatment CT predict volumetric response to chemotherapy in patients with colorectal liver metastases

OBJECTIVES

This study investigates whether quantitative image analysis of pretreatment CT scans can predict volumetric response to chemotherapy for patients with colorectal liver metastases (CRLM).

METHODS

Patients treated with chemotherapy for CRLM (hepatic artery infusion (HAI) combined with systemic or systemic alone) were included in the study. Patients were imaged at baseline and approximately 8 weeks after treatment. Response was measured as the percentage change in tumour volume from baseline. Quantitative imaging features were derived from the index hepatic tumour on pretreatment CT, and features statistically significant on univariate analysis were included in a linear regression model to predict volumetric response. The regression model was constructed from 70% of data, while 30% were reserved for testing. Test data were input into the trained model. Model performance was evaluated with mean absolute prediction error (MAPE) and R². Clinicopatholologic factors were assessed for correlation with response.

RESULTS

157 patients were included, split into training (n = 110) and validation (n = 47) sets. MAPE from the multivariate linear regression model was 16.5% (R² = 0.774) and 21.5% in the training and validation sets, respectively. Stratified by HAI utilisation, MAPE in the validation set was 19.6% for HAI and 25.1% for systemic chemotherapy alone. Clinical factors associated with differences in median tumour response were treatment strategy, systemic chemotherapy regimen, age and KRAS mutation status (p < 0.05).

CONCLUSION

Quantitative imaging features extracted from pretreatment CT are promising predictors of volumetric response to chemotherapy in patients with CRLM. Pretreatment predictors of response have the potential to better select patients for specific therapies.

KEY POINTS

• Colorectal liver metastases (CRLM) are downsized with chemotherapy but predicting the patients that will respond to chemotherapy is currently not possible. • Heterogeneity and enhancement patterns of CRLM can be measured with quantitative imaging. • Prediction model constructed that predicts volumetric response with 20% error suggesting that quantitative imaging holds promise to better select patients for specific treatments.

Comparison of early radiological predictors of outcome in patients with colorectal cancer with unresectable hepatic metastases treated with bevacizumab

OBJECTIVE

The purpose was to validate the prognostic value of an early optimal morphological response on CT in patients treated with bevacizumab-containing chemotherapy for unresectable colorectal cancer liver metastases (CLM). It also evaluated the prognostic value of size-based criteria and the association of optimal morphological response with the receipt of bevacizumab.

DESIGN

141 patients treated first using bevacizumab and 142 patients from a randomised study evaluating the addition of bevacizumab to oxaliplatin-based chemotherapy were retrospectively analysed. Radiologists evaluated pretreatment and restaging CT scans using morphological response criteria. Responses were also assessed with size-based criteria: Response Evaluation Criteria in Solid Tumors (RECIST), early tumour shrinkage (ETS) and deepness of response (DpR). The ability of each criterion to predict progression-free survival (PFS), overall survival (OS) and postprogression survival (PPS) was determined using a univariate Cox proportional hazards model.

RESULTS

In both populations, median PFS was significantly longer for patients achieving an optimal morphological response (10.4 vs 6.8 months, p=0.03; and 8.3 vs 4.9 months, p<00001, respectively). Neither RECIST nor ETS responses were associated with a prolonged PFS. Median OS was longer for those with an optimal morphological response but only at second restaging in the first population (n=141, 20.8 vs 12.3 months, p=0.002). DpR but not optimal morphological response was associated with PPS. In the randomised study, an optimal morphological response was 6.2 times more likely among patients receiving bevacizumab (p<0.0001).

CONCLUSION

In patients with unresectable CLM, early morphological response may be a better predictor of PFS than size-based response. The addition of bevacizumab improves morphological response rate.

Exploration of time points and cut-off values for early tumour shrinkage to predict survival outcomes of patients with metastatic colorectal cancer treated with first-line chemotherapy using a biexponential model for change in tumour size

Background

Several studies reported that early tumour shrinkage (ETS) was associated with overall survival in patients with metastatic colorectal cancer (mCRC) treated with first-line chemotherapy. However, appropriate time point and cut-off value for ETS remain unclear because these varied in previous studies.

Patients and methods

We investigated patients with mCRC who received FOLFOX or FOLFIRI with/without molecular-targeted agents as first-line treatment between 2005 and 2014. Using a biexponential model for change in tumour size, a relative change in the sum of the longest diameters of target lesions from baseline was estimated at a certain time point in each individual patient. Associations of survival outcomes with ETS at various time points based on various cut-off values were evaluated by Cox regression analysis with a landmark approach.

Results

Among the 67 patients reviewed, the objective response rate was 73.1% (95% CI 62.5% to 83.7%), the median progression-free survival was 10.9 months (95% CI 8.7 to 13.0 months) and the median overall survival was 25.6 months (95% CI 20.1 to 27.3 months). The model for change in tumour size agreed with the actual measured sizes well. Multivariate Cox regression analysis, including performance status, number of metastatic sites and use of targeted agents, showed that ETS at 8 weeks based on a cut-off value of 20% was most significantly associated with overall survival (HR: 0.404, 95% CI 0.231 to 0.707, P=0.0015).

Conclusion

It is suggested that a time point of 8 weeks and a cut-off value of 20% may be optimal criteria for defining ETS.

Early tumor shrinkage indicates a favorable response to bevacizumab-based first-line chemotherapy for metastatic colorectal cancer

A close correlation between early tumor shrinkage (ETS) and overall survival (OS) has been shown in antiepidermal growth factor receptor antibody-based chemotherapies for metastatic colorectal cancer (mCRC), but the clinical impact of ETS in bevacizumab-based chemotherapy has not been adequately clarified. Clinical data of mCRC patients who started initial chemotherapy without antiepidermal growth factor receptor antibody from 2005 to 2010 were retrospectively evaluated. The relative change in tumor size after 8 weeks of chemotherapy expected from the first image assessment [estimated ETS (EETS)] and the relative change in the tumor size at the nadir compared with the baseline [depth of response (DPR)] were examined. Seventy-three patients were enrolled and 61 patients were evaluable for survival by simple regression analysis. Bevacizumab-based chemotherapies were administered to 40 (66%) patients. The median EETS, DPR, progression-free survival, and OS were 16.1%, 27.2%, 8.0 months, and 19.5 months, respectively. Progression-free survival showed a positive correlation with OS (R=0.429), whereas EETS and DPR were less correlated with OS (R=0.0682, 0.186). EETS was well correlated with DPR (R=0.659). Patients with EETS greater than 16.12% were predicted to achieve tumor shrinkage of more than 30% at the maximum response. EETS in bevacizumab-treated mCRC showed a close correlation with DPR, which suggested that EETS might be useful, indicating a favorable response in treatment with bevacizumab-based chemotherapy.

BRAZILIAN CONSENSUS FOR MULTIMODAL TREATMENT OF COLORECTAL LIVER METASTASES. MODULE 3: CONTROVERSIES AND UNRESECTABLE METASTASES

In the last module of this consensus, controversial topics were discussed. Management of the disease after progression during first line chemotherapy was the first discussion. Next, the benefits of liver resection in the presence of extra-hepatic disease were debated, as soon as, the best sequence of treatment. Conversion chemotherapy in the presence of unresectable liver disease was also discussed in this module. Lastly, the approach to the unresectable disease was also discussed, focusing in the best chemotherapy regimens and hole of chemo-embolization.

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.

On-treatment markers as predictors to guide anti-EGFR MoAb treatment in metastatic colorectal cancer: a systematic review with meta-analysis

PURPOSE

Skin toxicity (ST) and early tumor shrinkage (ETS) are early phenomenon during the anti-epidermal growth factor receptor (EGFR) monoclonal antibody (MoAb) treatment. We conducted a meta-analysis and included relevant studies that reported the impact of ST and ETS on survival- and life quality-based outcome of metastatic colorectal cancer (mCRC) patients treated with anti-EGFR MoAb.

METHODS

Relevant studies were identified from PubMed and Embase reporting the correlation of ST and ETS with the clinical outcome of mCRC patients treated with anti-EGFR MoAb. We also collected evidences on the impact of ST and ETS on absolute benefit acquired from additional anti-EGFR treatment and quality of life (ST only). Pooled hazard ratio and rate difference were all estimated by using random-effects model.

RESULTS

Pooled data revealed that the occurrence of ST and ETS ≥20% (v < 20%) during anti-EGFR MoAb treatment were both associated with better OS, PFS and ORR. This association could not be disturbed by KRAS status. Mean changes in safety follow-up life health state from baseline appeared unaffected by ST. Only mCRC patients with wild-type KRAS tumor who suffered grade 2+ ST could benefit from additional anti-EGFR treatment to chemotherapy or best supportive care (BSC) alone. ETS was also a predictor for absolute survival benefit acquired from additional anti-EGFR treatment for patients with wild-type KRAS tumors, and the more early shrinkage the tumor was, the much benefit was observed.

CONCLUSION

ST and ETS are predictive of absolute benefit acquired from anti-EGFR treatment in mCRC patients with wild-type KRAS tumors. These two on-treatment markers can be used for clinical decision-making if no adequate biological markers from tissues are provided.

Aggregation Effects and Population-Based Dynamics as a Source of Therapy Resistance in Cancer

OBJECTIVE

Evolution of resistance allows cancer cells to adapt and continue proliferating even when therapy is initially very effective. Most investigations of treatment resistance focus on the adaptive phenotypic properties of individual cells. We propose that the resistance of a single cell to therapy may extend beyond its own phenotypic and molecular properties and be influenced by the phenotypic properties of surrounding cells and variations in cell density. Similar variation exists in population densities of animals living in groups and can significantly affect the outcome of an external threat.

METHODS

We investigate aggregation effects in cancer therapy using Darwinian models that integrate phenotypic properties of individual cells and common population effects found in nature to simulate the dynamics of resistance and sensitivity in the diverse cellular environments within cancers.

RESULTS

We demonstrate that the density of cancer cell populations can profoundly influence response to chemotherapy independent of the properties of individual cells. Most commonly, these aggregation effects benefit the tumor allowing cells to survive even with phenotypic properties that would render them highly vulnerable to therapy in the absence of population effects.

CONCLUSION

We demonstrate aggregation effects likely play a significant role in conferring resistance to therapy on tumor cells that would otherwise be sensitive to treatment.

SIGNIFICANCE

The potential role of aggregation in outcomes from cancer therapy has not been previously investigated. Our results demonstrate these dynamics may play a key role in resistance to therapy and could be used to design evolutionarily-enlightened therapies that exploit aggregation effects to improve treatment outcomes.

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.

Rebound growth of hepatic colorectal metastases after neo-adjuvant chemotherapy: effect on survival after resection

BACKGROUND

A period of recovery is commonly allowed between completion of chemotherapy for colorectal liver metastases (CRLM) and resection, during which tumour progression may occur. The study-aim is to assess the growth of CRLM in this interval and association with outcome.

METHOD

Data on 146 patients were analysed. Change in tumour size was assessed by comparing size determined by imaging performed on completion of chemotherapy with that determined by examination of the resected specimen, categorised by RECIST criteria.

RESULTS

In the interval before surgery sixteen patients (11%) fulfilled criteria for partial response (PR), 48 (33%) had stable disease (SD) and 82 (56%) had progressive disease (PD). Among patients with PD following chemotherapy the median disease-free survival of patients who initially responded (26 months) was longer than in those who initially had stable disease (7 months) (P = 0.002). No association was noted between rate of tumour growth after completion of chemotherapy and disease-free survival.

CONCLUSION

Change in tumour size after completion of chemotherapy is variable and can be rapid, especially in patients who initially respond to treatment. However, disease-free survival is determined by tumour behaviour during treatment and not by change in size after completion of chemotherapy.

Is early response by (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography a predictor of long-term outcome in patients with metastatic colorectal cancer?

BACKGROUND

Identify in advance responder patients to chemotherapy in metastatic colorectal cancer (CRC) would allow prompt interruption of ineffective therapies in non-responder patients. Hence, predictive markers are sought in numerous trials to detect responder patients, including tumor shrinkage measured by imaging methods. Usually, Response Evaluation Criteria in Solid Tumors (RECIST) is used to evaluate tumor response in metastatic CRC, but these criteria are questionable with use of biological agents associated to chemotherapy. Our aim was correlate early metabolic response by (18)F-2-fluoro-2-deoxy-D-glucose positron emission tomography-computed tomography ((18)FDG-PET-CT) with long-term outcome in metastatic CRC in first-line therapy.

METHODS

We prospectively evaluated 36 patients with metastatic CRC in first-line treatment with 5-fluorouracil, leucovorin (folinic acid), oxaliplatin (FOLFOX) or 5-fluorouracil, leucovorin (folinic acid), irinotecan (FOLFIRI) associated with cetuximab or bevacizumab. (18)FDG-PET-CT was performed at baseline and after two cycles of chemotherapy. The early metabolic response [standardized uptake value (SUV)] was measured to identify responder and non-responder patients and correlated with overall survival (OS) and progression-free survival (PFS).

RESULTS

Median age was 58.5 years (range, 41-74 years). PFS was 15.5 months for responder and 13.3 months for non-responder (P=0.42), OS was 55.7 months for responder and not reached for non-responder. There was no correlation between delta-SUV and clinical and pathological variables analyzed. In the subgroup of patients who did not undergo resection of metastasis (45%), PFS was higher for responders (15.3×6.8 months, P=0.02).

CONCLUSIONS

According to our findings, early response by (18)FDG-PET-CT was not a predictor of long-term outcome for patients with metastatic CRC treated in the first-line chemotherapy with a monoclonal antibody.

Models for change in tumour size, appearance of new lesions and survival probability in patients with advanced epithelial ovarian cancer

AIMS

The aims of this study were (i) to develop a modelling framework linking change in tumour size during treatment to survival probability in metastatic ovarian cancer; and (ii) to model the appearance of new lesions and investigate their relationship with survival and disease characteristics.

METHODS

Data from a randomized Phase III clinical trial comparing carboplatin monotherapy to gemcitabine plus carboplatin combotherapy in 336 patients with metastatic ovarian cancer were used. A population model describing change in tumour size based on drug treatment information was established and its relationship with time to appearance of new lesions and survival were investigated with time to event models.

RESULTS

The tumour size profiles were well characterized as evaluated by visual predictive checks. Metastasis in the liver at enrolment and change in tumour size up to week 12 were predictors of time to appearance of new lesions. Survival was predicted based on the patient tumour size and ECOG performance status at enrolment and on appearance of new lesions during treatment and change in tumour size up to week 12. Tumour size and survival data from a separate study were adequately predicted.

CONCLUSIONS

The proposed models simulate tumour dynamics following treatment and provide a link to the probability of developing new lesions as well as to survival. The models have potential to be used for optimizing the design of late phase clinical trials in metastatic ovarian cancer based on early phase clinical study results and simulation.

Optimizing clinical benefit with targeted treatment in mRCC: "Tumor growth rate" as an alternative clinical endpoint

Tumor growth rate (TGR), usually defined as the ratio between the slope of tumor growth before the initiation of treatment and the slope of tumor growth during treatment, between the nadir and disease progression, is a measure of the rate at which tumor volume increases over time. In patients with metastatic renal cell carcinoma (mRCC), TGR has emerged as a reliable alternative parameter to allow a quantitative and dynamic evaluation of tumor response. This review presents evidence on the correlation between TGR and treatment outcomes and discusses the potential role of this tool within the treatment scenario of mRCC. Current evidence, albeit of retrospective nature, suggests that TGR might represent a useful tool to assess whether treatment is altering the course of the disease, and has shown to be significantly associated with progression-free survival and overall survival. Therefore, TGR may represent a valuable endpoint for clinical trials evaluating new molecularly targeted therapies. Most importantly, incorporation of TGR in the assessment of individual patients undergoing targeted therapies may help clinicians decide if a given agent is no longer able to control disease growth and whether continuing therapy beyond RECIST progression may still produce clinical benefit.

"New" metastases are associated with a poorer prognosis than growth of pre-existing metastases in patients with metastatic breast cancer treated with chemotherapy

Introduction

Progression-free survival (PFS) and overall survival (OS) endpoints often only weakly correlate. This analysis investigates how different progression events impact on OS, using data from two phase 3 studies with eribulin in women with advanced/metastatic breast cancer (MBC).

Methods

In Study 301, 1102 women with ≤2 prior chemotherapies for advanced/MBC were randomized to eribulin mesylate (1.4 mg/m² on days 1 and 8 every 21 days) or capecitabine (1.25 g/m² twice daily on days 1–14 every 21 days). Study 305/EMBRACE enrolled 762 patients following two to five prior chemotherapies for advanced/MBC, randomized to eribulin (as above) or treatment of physician’s choice. We analyzed OS and PFS post hoc for patients whose disease progressed due to development of “new” metastases, growth of pre-existing lesions, and patients with no reported disease progression.

Results

In both clinical studies, development of new metastases was associated with an increased risk of death (p < 0.0001). The time to development of new metastasis or death was significantly longer with eribulin than the comparator in Study 305 (p = 0.0017), but not in Study 301 (p = 0.46). Significantly longer OS was observed in the eribulin compared with the comparator arm for the new metastases subgroup in Study 301 (p = 0.008), but not in Study 305 (p = 0.16), compared with other progression subgroups.

Conclusions

Patients with MBC progressing with new metastases have a worse prognosis than those whose disease progresses due to growth of existing lesions or patients with no reported disease progression. These findings have potentially important implications for the interpretation of clinical study data and clinical practice.

Trial registration

ClinicalTrials.gov registration IDs: Study 301: NCT00337103; Study 305: NCT00388726.

Clinical Utility of Metrics Based on Tumor Measurements in Phase II Trials to Predict Overall Survival Outcomes in Phase III Trials by Using Resampling Methods

PURPOSE

Phase II clinical trials inform go/no-go decisions for proceeding to phase III trials, and appropriate end points in phase II trials are critical for facilitating this decision. Phase II solid tumor trials have traditionally used end points such as tumor response defined by Response Evaluation Criteria for Solid Tumors (RECIST). We previously reported that absolute and relative changes in tumor measurements demonstrated potential, but not convincing, improvement over RECIST to predict overall survival (OS). We have evaluated the metrics by using additional measures of clinical utility and data from phase III trials.

METHODS

Resampling methods were used to assess the clinical utility of metrics to predict phase III outcomes from simulated phase II trials. In all, 2,000 phase II trials were simulated from four actual phase III trials (two positive for OS and two negative for OS). Cox models for three metrics landmarked at 12 weeks and adjusted for baseline tumor burden were fit for each phase II trial: absolute changes, relative changes, and RECIST. Clinical utility was assessed by positive predictive value and negative predictive value, that is, the probability of a positive or negative phase II trial predicting an effective or ineffective phase III conclusion, by prediction error, and by concordance index (c-index).

RESULTS

Absolute and relative change metrics had higher positive predictive value and negative predictive value than RECIST in five of six treatment comparisons and lower prediction error curves in all six. However, differences were negligible. No statistically significant difference in c-index across metrics was found.

CONCLUSION

The absolute and relative change metrics are not meaningfully better than RECIST in predicting OS.

'Deepness of Response' Is Associated with Overall Survival in Standard Systemic Chemotherapy for Metastatic Colorectal Cancer

BACKGROUND

The identification of responders is an important issue in chemotherapy for metastatic colorectal cancer (mCRC). 'Deepness of response' (DpR), defined as the maximum rate of reduction from the initial tumor burden, was recently proposed as a novel hypothetical parameter associated with overall survival (OS) in first-line chemotherapy plus cetuximab for mCRC. We determined whether this concept was universally applicable to diverse standard chemotherapeutic regimens for mCRC.

METHODS

We reviewed mCRC patients who received the first-line systemic chemotherapy regimens FOLFOX, CapeOX or FOLFIRI (with biologics) at our department between June 2005 and March 2015. Data such as clinicopathological parameters, metastasized organs, chemotherapeutic regimens, the best response by RECIST v1.1, progression-free survival (PFS) and OS were retrospectively retrieved for patients who exhibited tumor shrinkage. DpR was calculated as the uni-dimensional maximum reduction rate of measurable tumors. We addressed the association between DpR and survival.

RESULTS

Of the 156 patients receiving first-line chemotherapy regimens, tumor shrinkage was observed in 63 (41 of whom were men; median age 62 years). Complete remission was achieved in 6 patients, partial remission in 42 and stable disease in 15. The median DpR was 44.2% and was employed as the cutoff, in line with previous reports. DpR ≥45% (31 patients) was correlated with longer PFS (median 16.4 vs. 8.1 months for DpR <45%, p = 0.006) and OS (median 58.6 vs. 30.9 months for DpR <45%, p = 0.041). There was basically no difference in the subsequent chemotherapy between the DpR ≥45% and DpR <45% groups.

CONCLUSION

DpR correlated with OS in various first-line systemic upfront chemotherapy regimens for mCRC.

Evaluating Continuous Tumor Measurement-Based Metrics as Phase II Endpoints for Predicting Overall Survival

BACKGROUND

We sought to develop and validate clinically relevant, early assessment continuous tumor measurement-based metrics for predicting overall survival (OS) using the Response Evaluation Criteria in Solid Tumors (RECIST) 1.1 data warehouse.

METHODS

Data from 13 trials representing 2096 patients with breast cancer, non-small cell lung cancer (NSCLC), or colorectal cancer were used in a complete case analysis. Tumor measurements from weeks 0-6-12 assessments were used to evaluate the ability of slope (absolute change in tumor size from 0-6 and 6-12 weeks) and percent change (relative change in tumor size from 0-6 and 6-12 weeks) metrics to predict OS using Cox models, adjusted for average baseline tumor size. Metrics were evaluated by discrimination (via concordance or c-index), calibration (goodness-of-fit type statistics), association (hazard ratios), and likelihood (Bayesian Information Criteria), with primary focus on the c-index. All statistical tests were two-sided.

RESULTS

Comparison of c-indices suggests slight improvement in predictive ability for the continuous tumor measurement-based metrics vs categorical RECIST response metrics, with slope metrics performing better than percent change metrics for breast cancer and NSCLC. However, these differences were not statistically significant. The goodness-of-fit statistics for the RECIST metrics were as good as or better than those for the continuous metrics. In general, all the metrics performed poorly in breast cancer, compared with NSCLC and colorectal cancer.

CONCLUSION

Absolute and relative change in tumor measurements do not demonstrate convincingly improved overall survival predictive ability over the RECIST model. Continued work is necessary to address issues of missing tumor measurements and model selection in identifying improved tumor measurement-based metrics.