Prediction of Response to Anti-Angiogenic Treatment for Advanced Colorectal Cancer Patients: From Biological Factors to Functional Imaging.

Colorectal cancer (CRC) is a leading tumor worldwide. In CRC, the angiogenic pathway plays a crucial role in cancer development and the process of metastasis. Thus, anti-angiogenic drugs represent a milestone for metastatic CRC (mCRC) treatment and lead to significant improvement of clinical outcomes. Nevertheless, not all patients respond to treatment and some develop resistance. Therefore, the identification of predictive factors able to predict response to angiogenesis pathway blockade is required in order to identify the best candidates to receive these agents. Unfortunately, no predictive biomarkers have been prospectively validated to date. Over the years, research has focused on biologic factors such as genetic polymorphisms, circulating biomarkers, circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and microRNA. Moreover, research efforts have evaluated the potential correlation of molecular biomarkers with imaging techniques used for tumor assessment as well as the application of imaging tools in clinical practice. In addition to functional imaging, radiomics, a relatively newer technique, shows real promise in the setting of correlating molecular medicine to radiological phenotypes.

Immunotherapy in small bowel adenocarcinoma: a potential role?

Small bowel adenocarcinoma (SBA) is a rare tumor with an unfavorable prognosis, and due to its rarity, few studies on its treatment are available. Chemotherapy remains the standard of treatment in advanced disease. Recently immunotherapy has demonstrated to be a valid therapeutic option for many solid tumors. We reviewed the data published in literature to understand the impact of immunotherapy in this cancer.

New Horizons in Metastatic Colorectal Cancer: Prognostic Role of CD44 Expression.

BACKGROUND: The transmembrane glycoprotein CD44, the major hyaluronan (HA) receptor, has been proven to regulate cell growth, survival, differentiation, and migration. It is therefore widely considered to be involved in carcinogenesis. Its role as a new therapeutic target in solid tumors is under evaluation in clinical trials. The prognostic value remains controversial. Here, we aimed to investigate the correlation between CD44 expression and the clinicopathological features and survival in metastatic colorectal cancer (mCRC) patients. METHODS: Data from 65 mCRC patients of the Medical Oncology Unit, University Hospital and University of Cagliari were retrospectively collected from 2008 to 2021. Immunohistochemical analysis was performed at the Pathology Division, University Hospital of Cagliari on 3 µm thick sections obtained from paraffin blocks. The intensity of immunohistochemical staining was subclassified into four groups: score 0 if negative or weak membrane staining in less than 10% of tumor cells; score 1+ if weak membrane staining in at least 10% of tumor cells or moderate membrane staining in less than 10% of tumor cells; score 2+ if moderate membrane staining in at least 10% of tumor cells or intensive membrane staining in less than 10% of tumor cells; score 3+ if intense membrane staining in at least 10% of tumor cells. Based on this score, we distinguished patients into low CD44 expression (score 0, 1+, 2+) and high CD44 expression (score 3+). Statistical analysis was performed with MedCalc (survival distribution: Kaplan-Meier; survival comparison: log-rank test; association between categorical variables: Fisher's exact test). RESULTS: Patients' median age was 66 years (range 49-85). Regarding CD44 expression, score was 0 in 18 patients, 1+ in 15 patients, 2+ in 18 patients, and 3+ in 14 patients. Median overall survival (mOS) was 28.1 months (95%CI: 21.3-101). CD44 overexpression (3+) was correlated with poor prognosis (p = 0.0011; HR = 0.2), with a mOS of 14.5 months (95%CI 11.7 to 35.9) versus 30.7 months (95%CI 27.8 to 101) in lower CD44 expression. Higher CD44 expression was associated with clinically poor prognostic features: age ≥ 70 years (p = 0.0166); inoperable disease (p = 0.0008); stage IV at diagnosis (p = 0.0241); BRAF mutated (p = 0.0111), high-grade tumor (p = 0.0084). CONCLUSIONS: CD44 markedly correlated with aggressive tumor behavior and contributed to the earlier progression of disease, thus suggesting its role as a novel prognostic marker and potential therapeutic target for mCRC patients.

Does immunotherapy change the treatment paradigm in metastatic gastric cancer?

Gastric cancer represents one of the leading causes of cancer-related death worldwide. Even if the last decade has witnessed an improvement in surgical and systemic treatments, with an increase of overall life expectancy, survival rates still remain unsatisfactory, especially for patients with metastatic disease. Systemic therapies represent the gold standard in the management of stage IV gastric cancer. In this scenario, the availability of effective second and third lines has represented for a long time the only hope to offer an overall survival improvement to these patients. Recently, the advent of immune checkpoint inhibitors has involved also gastric cancer with encouraging efficacy data in the metastatic setting, becoming integral part of the management of selected patients.

How to improve metastatic pancreatic ductal adenocarcinoma patients' selection: Between clinical trials and the real-world.

As underlined in the minireview by Blomstrand et al, given the poor prognosis and the paucity of data on a therapeutic sequence in pancreatic ductal adenocarcinoma (PDAC), additional randomized controlled trials and real-world evidence studies addressing current and novel regimens are needed. The real-world outcomes of first-line chemotherapy regimens such as FOLFIRINOX and gemcitabine/nab-paclitaxel are thoroughly reviewed and seem to be largely generalizable in a real-world context. Regarding second-line chemotherapy, the key question about the optimal sequence of regimens remains uncertain. Precisely in this setting, it is therefore useful to encourage the implementation of clinical studies that may contribute to the scarcity of data available up to now. We report our experience with a small group of patients treated with second-line liposomal irinotecan (nal-IRI) plus 5-fluorouracil and leucovorin. To improve the treatment of patients affected by PDAC, it is useful to identify subgroups of patients who may benefit from target treatments (e.g., BRCA mutant) and it is also important to focus on any prognostic factors that may affect the survival and treatment of these patients.

EGFR-Mutated Non-Small Cell Lung Cancer and Resistance to Immunotherapy: Role of the Tumor Microenvironment.

Lung cancer is a leading cause of cancer-related deaths worldwide. About 10-30% of patients with non-small cell lung cancer (NSCLC) harbor mutations of the EGFR gene. The Tumor Microenvironment (TME) of patients with NSCLC harboring EGFR mutations displays peculiar characteristics and may modulate the antitumor immune response. EGFR activation increases PD-L1 expression in tumor cells, inducing T cell apoptosis and immune escape. EGFR-Tyrosine Kinase Inhibitors (TKIs) strengthen MHC class I and II antigen presentation in response to IFN-γ, boost CD8+ T-cells levels and DCs, eliminate FOXP3+ Tregs, inhibit macrophage polarization into the M2 phenotype, and decrease PD-L1 expression in cancer cells. Thus, targeted therapy blocks specific signaling pathways, whereas immunotherapy stimulates the immune system to attack tumor cells evading immune surveillance. A combination of TKIs and immunotherapy may have suboptimal synergistic effects. However, data are controversial because activated EGFR signaling allows NSCLC cells to use multiple strategies to create an immunosuppressive TME, including recruitment of Tumor-Associated Macrophages and Tregs and the production of inhibitory cytokines and metabolites. Therefore, these mechanisms should be characterized and targeted by a combined pharmacological approach that also concerns disease stage, cancer-related inflammation with related systemic symptoms, and the general status of the patients to overcome the single-drug resistance development.

Liquid Biopsy-Driven Cetuximab Rechallenge Strategy in Molecularly Selected Metastatic Colorectal Cancer Patients.

Background: Rechallenge with EGFR inhibitors represents a promising strategy for patients with RAS wild type (WT) colorectal cancer (CRC) but definitive selection criteria are lacking. Recently, the RAS WT status on circulating tumor DNA (ct-DNA) emerged as a potential watershed for this strategy. Our study explored the liquid biopsy-driven cetuximab rechallenge in a RAS and BRAF WT selected population. Methods: CRC patients with RAS and BRAF WT both on tumor tissue and on ct-DNA at baseline receiving rechallenge with cetuximab were eligible for our analysis. Ct-DNA was analyzed for RAS-BRAF mutations with pyro-sequencing and nucleotide sequencing assays. Real-time PCR and droplet digital PCR were performed to confirm the RAS-BRAF mutational status. Results: A total of 26 patients were included in our analysis. In the global population, RR was 25.0%, median overall survival (mOS) was 5.0 months, and median progression-free survival (mPFS) was 3.5 months. Previous response to anti-EGFR was associated with improved mPFS (5.0 vs. 2.0 months, HR: 0.26, p = 0.048); anti-EGFR free interval > 14 months and anti-EGFR free interval > 16 months were associated with improved mPFS (respectively 7.0 vs. 3.0 months, HR: 0.27, p = 0.013 and not reached vs. 3.0 months, HR: 0.20, p = 0.002) and with improved mOS (respectively 13.0 vs. 5.0 months, HR: 0.27, p = 0.013 and 13.0 vs. 5.0 months, HR: 0.20, p = 0.002). Previous lines >2 were correlated with improved mPFS (4.0 vs. 1.0 month, HR: 0.05, p = 0.041) and with improved mOS (7.0 vs. 1.0 month, HR: 0.045, p = 0.034). In a multiple logistic regression model, only the anti-EGFR free interval was confirmed to be a significant predictor for mOS and mPFS. Conclusions: Liquid biopsy-driven cetuximab rechallenge was confirmed to be effective. The clinical outcome was consistent with available results from phase II studies. In addition to the molecular selection through the analysis of ct-DNA for RAS, the long anti-EGFR free interval is confirmed as a prospective selection criterion for this therapeutic option.

The role of immune checkpoint inhibitors in the treatment sequence of advanced gastric or gastro-esophageal junction cancer: A systematic review and meta-analysis of randomized trials.

PURPOSE: This study aimed to clarify the current knowledge on the use of immunotherapy in patients with advanced gastric(G)/gastroesophageal(GEJ) cancers. MATERIALS AND METHODS: A meta-analysis was done to evaluate the efficacy of immune checkpoint inhibitors(ICIs) in G/GEJ cancer both in the unselected population and in that stratified for combined positive score (CPS)≥ 1 and ≥ 10 patients. RESULTS: In the unselected population the result showed 21%(P < 0.00001), and 29%(P < 0.00001) reduction of death and progression risk for patients treated with ICIs compared without ICIs, while in CPS≥ 1 and≥ 10 populations, the result showed a death reduction of 19%(P = 0.001) and 33%(P < 0.00001) respectively, and, and 23% (P < 0.00001) and 43% (P < 0.00001) progression risk reduction respectively, for patients treated with and without ICIs. CONCLUSION: overall survival(OS) and progression free survival(PFS) data obtained in our meta-analysis, are in favor to use ICIs in association with standard first line chemotherapy for G/GEJ cancer patients regardless to CPS status.

Why does survival of hepatocellular carcinoma patients remain so low? Key stumbling blocks and questions in preclinical and clinical development.

INTRODUCTION: Hepatocellular carcinoma (HCC) is a complex disease, which involves diverse molecular pathways and etiologies. In recent years, several new systemic treatments have improved survival in advanced stage disease, but numerous significant challenges remain. No significant improvements have been achieved in the intermediate stage disease; this may be attributed to the difficulties in stratification of patients and the broad spectrum of clinical situations in terms of tumor burden and liver function. AREAS COVERED: This article considers the recent progress in first- and second-line therapy for advanced HCC. Investigational strategies conducted in intermediate stage HCC, which involve mainly combination therapy with locoregional approaches, and systemic drugs, antiangiogenics, immunotherapies (or both) are then examined. Later, the paper offers insights on the questions and challenges that lie ahead for treating HCC. EXPERT OPINION: Clinical and biomolecular markers for the stratification of patients are needed for therapeutic progress. Further molecular profiling data could enhance our knowledge of the molecular pathways underlying this tumor and facilitate the identification of targetable aberrations. This could offer opportunities for precision medicine approaches and improved survival.

Uncovering key targets of success for immunotherapy in pancreatic cancer.

INTRODUCTION: Despite available treatment options, pancreatic ductal adenocarcinoma (PDAC) is frequently lethal. Recent immunotherapy strategies have failed to yield any notable impact. Therefore, research is focussed on unearthing new drug targets and therapeutic strategies to tackle this malignancy and attain more positive outcomes for patients. AREAS COVERED: In this perspective article, we evaluate the main resistance mechanisms to immune checkpoint inhibitors (ICIs) and the approaches to circumvent them. We also offer an assessment of concluded and ongoing trials of PDAC immunotherapy. Literature research was performed on Pubmed accessible through keywords such as: 'pancreatic ductal adenocarcinoma,' 'immunotherapy,' 'immunotherapy resistance,' 'immune escape,' 'biomarkers.' Papers published between 2000 and 2021 were selected. EXPERT OPINION: The tumor microenvironment is a critical variable of treatment resistance because of its role as a physical barrier and inhibitory immune signaling. Promising therapeutic strategies appear to be a combination of immunotherapeutics with other targeted treatments. Going forward, predictive biomarkers are required to improve patient selection. Biomarker-driven trials could enhance approaches for assessing the role of immunotherapy in PDAC.

Emerging treatment evolutions and integrated molecular characteristics of biliary tract cancers.

Biliary tract cancers (BTCs) consist of a group of highly heterogeneous malignancies that are characterized by genomic differences among tumors from different anatomic sites. The current treatment for BTC includes surgery, chemotherapy, target therapy, and immunotherapy. Although surgery remains the primary option for localized disease, representing the only potential curative treatment, a high risk of recurrence cannot be neglected. Chemotherapy has been considered the standard of care for both advanced and metastatic disease and in adjuvant settings. However, drug resistance is a major obstacle associated with chemotherapy. The development of genetic testing technologies, including next-generation sequencing, has opened the door for the identification of drug targets and candidate molecules. A series of preclinical studies has demonstrated the role of gene mutations, abnormal signaling pathways, and immunosuppression in the pathogenesis of BTC, laying the foundation for the application of targeted therapy and immunotherapy. A variety of molecularly targeted agents, including pemigatinib, have shown promising survival benefits in patients with advanced disease. The rapidly evolving role of multimodal therapy represents the subject of this review.

Molecular-driven treatment for biliary tract cancer: the promising turning point.

INTRODUCTION: In the past, targeted therapies have not shown positive results as they have been used without adequate molecular selection of patients with biliary tract cancer (BTC). This has led to an expansion of research on characteristics and molecular selection to identify new effective strategies in this setting. Improved knowledge of the molecular biology of these neoplasms has highlighted their extraordinary heterogeneity and has made it possible to identify targetable gene alterations, including fibroblast growth factor receptor (FGFR) 2 gene fusions, and isocitrate dehydrogenase (IDH) mutations. The FDA recently approved ivosidenib and pemigatinib for the treatment of BTCs. AREAS COVERED: We review data in the literature regarding targeted therapies for the treatment of BTCs, as well as on the prospects deriving from the extraordinary molecular heterogeneity of these neoplasms. EXPERT OPINION: At present, it is essential to evaluate the expression of the genetic alterations expressed by these neoplasms to offer patients an increasingly personalized therapeutic approach. Studies are needed to better define the limits and potentials of targeted therapies and their role in the therapeutic algorithm to improve the poor prognosis of these patients.

Long Term Survival With Regorafenib: REALITY (Real Life in Italy) Trial - A GISCAD Study.

BACKGROUND: Regorafenib is a key agent in metastatic colorectal cancer (mCRC), but no validated factors predicting longer survival are available. PATIENTS AND METHODS: REALITY was a retrospective multicenter trial in regorafenib-treated mCRC patients with overall survival (OS) ≥ 6 months. We aimed to assess the association between clinical parameters and outcome to define a panel identifying long term survivors among regorafenib candidates. Primary and secondary endpoints were OS and progression free survival (PFS), respectively. Statistical analysis was performed with MedCalc (survival distribution: Kaplan-Meier; survival comparison: log-rank test; independent role of significant variables at univariate analysis: logistic regression). RESULTS: Hundred regorafenib-treated mCRC patients with OS ≥ 6 months were enrolled. Median OS was 11.5 m (95%CI:9.60-12.96); median PFS was 4.2 months (95% CI:3.43-43.03). The absence of liver progression and of dose and/or schedule changes during the first 4 cycles (mainly for good tolerability) were independently correlated at multivariate analysis with OS (Exp(b)1.8869, P= .0277and Exp(b)2.2000, P = .0313) and PFS (Exp(b)2.1583, P = .0065 and Exp(b)2.3036, P= .0169). Patients with neither of these variables had a significantly improved OS (n = 14, 20.8 months; 95% CI:12.967-55.267) versus others (n = 86, 10 months; 95% CI:8.367-12.167; HR = 0.4902, P = .0045) and PFS (11.3 months, 95%CI:4.267-35.8 vs. 3.9 months, 95% CI:3.167-43.033; HR = 0.4648, P = .0086). CONCLUSION: These 2 factors might allow clinicians to better identify patients more likely to benefit from regorafenib. Toxicity management remains crucial.

BRCA-mutant pancreatic ductal adenocarcinoma.

Despite continued research, pancreatic ductal adenocarcinoma (PDAC) remains one of the main causes of cancer death. Interest is growing in the role of the tumour suppressors breast cancer 1 (BRCA1) and BRCA2-typically associated with breast and ovarian cancer-in the pathogenesis of PDAC. Indeed, both germline and sporadic mutations in BRCA1/2 have been found to play a role in the development of PDAC. However, data regarding BRCA1/2-mutant PDAC are lacking. In this review, we aim to outline the specific landscape of BRCA-mutant PDAC, focusing on heritability, clinical features, differences between BRCA1 and 2 mutations and between germline and sporadic alterations, as well as established therapeutic strategies and those that are still under evaluation.

The Role of p53 Expression in Patients with RAS/BRAF Wild-Type Metastatic Colorectal Cancer Receiving Irinotecan and Cetuximab as Later Line Treatment.

BACKGROUND: Preclinical and clinical data indicate that p53 expression might modulate the activity of the epidermal growth factor receptor (EGFR), influencing response/resistance to anti-EGFR monoclonal antibodies. However, the association between p53 status and clinical outcome has not been clarified yet. OBJECTIVE: In our study, we evaluated the role of p53 expression in patients with RAS/BRAF wild-type metastatic colorectal cancer (mCRC) receiving irinotecan/cetuximab in an exploratory and a validation cohort. PATIENTS AND METHODS: p53 expression was analysed in patients with RAS/BRAF wild-type mCRC receiving second-line or third-line irinotecan/cetuximab. Survival distribution was assessed by the Kaplan-Meier method, while the log-rank test was used for survival comparison. RESULTS: Among 120 patients with RAS/BRAF wild-type mCRC included in our analysis, 52 (59%) and 19 (59%) patients showed p53 overexpression in the exploratory and validation cohort, respectively. In the exploratory cohort, low p53 expression was correlated with better median progression-free survival (hazard ratio 0.39; p < 0.0001), median overall survival (hazard ratio: 0.23; p < 0.0001) and response rate (p < 0.0001). These results were confirmed by data of the validation cohort where we observed better median progression-free survival (hazard ratio: 0.48; p = 0.0399), median overall survival (hazard ratio: 0.26; p = 0.0027) and response rate (p =0.0007) in patients with p53 normal expression mCRC. CONCLUSIONS: In our study, p53 overexpression was associated with anti-EGFR treatment resistance in patients with RAS/BRAF WT mCRC, as confirmed in a validation cohort. Larger studies are needed to validate the role of p53 and investigate EGFR cross-talk in these patients.

The Difficult Task of Diagnosing Depression in Elderly People with Cancer: A Systematic Review.

Background: Depression is a common psychiatric problem in the elderly and oncology patients. In elderly people with cancer, depression has a peculiar phenomenology. It has a significant impact on the quality of life. Moreover, it is associated with poor adherence to treatments, increased risk of suicide, and mortality. Nevertheless, the topic of depression in elderly people with cancer remains unexplored. Objective: The main goal of this article is to review the literature from the past 20 years on the relationships between depression, cancer, and aging. Methods: The methods followed the Prisma model for eligibility of studies. The articles in which the keywords "depression", "cancer", " elderly, aging, or geriatric" were present, either in the text or in the abstract, were selected. 8.056 articles, by matching the keywords "depression and elderly and cancer," were identified. Only 532 papers met the eligibility criteria of search limits and selection process. Out of 532 papers, 467 were considered irrelevant, leaving 65 relevant studies. Out of 65 suitable studies, 39 (60.0%) met our quality criteria and were included. Results: The risk factors associated with depression in elderly people with cancer can be divided into 4 groups: 1) tumor-related; 2) anticancer treatment-related; 3) patients-related; 4) number and type of comorbidity. The main obstacles in diagnosing depression in elderly patients with cancer are the overlap of the symptoms of cancer and side effects of treatment with the symptoms of depression but also the different ways of reporting depressive symptoms of elderly people and the different clinical types of depression. There is a lack of data regarding validated scales to assess depression in geriatric patients with cancer. Any mental illness, specifically co-occurring anxiety and depression, increases the risk of diagnosis delay and anticancer treatment adherence. Cancer and the diagnosis of mental disorders prior to cancer diagnosis correlate with an increased risk for suicide. A non-pharmacological therapeutic approach, pharmacological treatment and/or a combination of both can be used to treat elderly patients with cancer, but a detailed analysis of comorbidities and the assessment of polypharmacy is mandatory in order to avoid potential side-effects and interactions between antidepressants and the other drugs taken by the patients. Conclusion: Future research should be conducted with the aim of developing a modified and adapted assessment method for the diagnosis and treatment of depression in elderly people with cancer in order to improve their clinical outcomes and quality of life.

Introducing immunotherapy for advanced hepatocellular carcinoma patients: Too early or too fast?

Advanced hepatocellular carcinoma (HCC) is the most frequent liver cancer. Immunotherapy has been explored in this disease in order to improve survival outcomes. Nowadays, scientific research is focusing especially on immune checkpoint inhibitors, in particular anti-PD1, anti-PD-L1 and anti-CTLA4 monoclonal antibodies (mAbs), as single-agent or in combination with other immunotherapy agents, target therapies, anti-vascular endothelial growth factor (VEGF) and other agents targeting specific molecular pathways. Other immunotherapy strategies have been assessed or are under investigation in advanced HCC, namely cytokines, adoptive cell therapy, oncolytic virus, cancer vaccines. Each treatment presents specific efficacy and toxicity profiles, strictly related to their mechanism of action and to advanced HCC tumour microenvironment (TME). The aim of this review is to outline the state-of-the-art of immunotherapy in advanced HCC treatment, highlighting data on already investigated treatment strategies, safety and toxicity (including HBV/HCV-related HCC), and ongoing clinical trials focusing on new promising therapeutic weapons.

Retrospective survival analysis in patients with metastatic pancreatic ductal adenocarcinoma with insulin-treated type 2 diabetes mellitus.

INTRODUCTION: The association between pancreatic ductal adenocarcinoma (PDAC) and type 2 diabetes mellitus (DM2) has long been evaluated and the role of antidiabetic medications such as metformin has also been investigated. The objective of this study was to examine the association between insulin use and overall survival (OS) in patients with advanced PDAC and DM2. METHODS: We retrospectively collected data from 164 patients, including an exploratory cohort of 96 patients from Medical Oncology Unit, University Hospital and University of Cagliari, Italy, and a validation cohort of 68 patients from Medical Oncology of Modena University Hospital. Patients had metastatic disease and received a first-line gemcitabine-based chemotherapy and, subsequently, a second-line fluoropyrimidines-based chemotherapy. We performed univariate analysis to evaluate correlation between long-term diabetes and overall survival. Then we performed multivariate analysis, adjusting for sex, metastatic sites, Eastern Cooperative Oncology Group Performance Status, Ca19.9 levels, N/L ratio, and lactate dehydrogenase levels at diagnosis, to confirm the independence of the variable. RESULTS: In the exploratory cohort, DM2 was significantly associated with higher median OS at univariate analysis (16 vs 10 months; p = 0.004). This result was confirmed by validation cohort (11 months vs 6 months; p = 0.01). In multivariate analysis, insulin-treated patients compared with non diabetic patients showed a significantly increased survival of 4.6 months (p = 0.03). CONCLUSIONS: Patients with insulin-treated metastatic PDAC showed better OS than non diabetic patients, as demonstrated by both cohorts. The correlation between OS and insulin-treated DM2 should be investigated further through a prospective clinical trial.

Retreatment With Anti-EGFR Antibodies in Metastatic Colorectal Cancer Patients: A Multi-institutional Analysis.

BACKGROUND: On the basis of retrospective analyses and phase 2 studies, metastatic colorectal cancer patients whose disease responded to a first-line regimen containing an anti-epidermal growth factor receptor (EGFR) agent may experience benefit from anti-EGFR readministration in later therapy lines. While the analysis of circulating tumor DNA seems a promising tool to select the best candidates for this strategy, identifying clinical predictors of anti-EGFR sensitivity would be useful to drive treatment choices in daily practice. PATIENTS AND METHODS: A real-life database of 5530 patients treated at 6 institutions was queried. Included were patients who were retreated with anti-EGFRs, who had RAS/BRAF wild-type-status tissue samples, who had received a first-line anti-EGFR-based regimen with at least stable disease as best response, and who had received at least one further line of therapy before anti-EGFR retreatment. The association with overall response rate (ORR), progression-free survival (PFS), and overall survival (OS) of variables potentially related to anti-EGFR sensitivity was investigated. RESULTS: A total of 86 patients were identified. The ORR during anti-EGFR retreatment was 19.8%; median PFS and OS were 3.8 and 10.2 months, respectively. No significant association of clinical features of anti-EGFR sensitivity with ORR, PFS, and OS was observed. Among the 56 patients with a time from the last anti-EGFR administration to first-line progressive disease of < 3 months (rechallenge group), > 2 prior therapy lines and a longer anti-EGFR-free interval were associated with higher ORR, but not with longer PFS or OS. CONCLUSION: Clinical features we deemed surrogates of anti-EGFR sensitivity were not reliable predictors of benefit from anti-EGFR retreatment.