A review and assessment of currently available data of the EGFR antibodies in elderly patients with metastatic colorectal cancer

Reduced-dose of doublet chemotherapy combined with anti-EGFR antibodies in vulnerable older patients with metastatic colorectal cancer: Data from the REVOLT study

OBJECTIVES

To assess the toxicity patterns and effectiveness of doublet chemotherapy when administered at reduced doses of 20% (FOLFOX or FOLFIRI) in combination with anti-EGFR antibodies (cetuximab or panitumumab) in old, vulnerable patients with metastatic colorectal cancer (mCRC).

PATIENTS AND METHODS

We performed a retrospective observational study of RAS and BRAF wild-type, vulnerable patients aged ≥70 years with previously untreated mCRC. The primary endpoint was safety, and secondary endpoints were overall response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

One hundred and eighteen patients were collected from 14 selected Italian centres. The median age was 75 (range, 70-85). Geriatric screening by G8 tool gave a score ≤ 14 in all patients. In total, 75 and 43 patients received FOLFOX or FOLFIRI, respectively, in combination with panitumumab (53%) or cetuximab (47%). The overall incidence of grade (G) 3-4 neutropenia was 11.8%, and for skin rash 11%. The most frequent adverse events were G1-2 skin rash (49.1%), G1-2 diarrhea (21.1%) and G1-2 nausea (17.7%). The ORR was 57.3%. Stable disease was observed in 29.1% of patients, with a disease control rate of 86.4%. With a median follow-up of 18 months, the median PFS was 10.0 months (95% confidence interval [CI]: 8.5-11.4), while the median OS was 18.0 months (95% CI: 16.0-19.9). No statistically significant difference was observed between the regimens in terms of ORR, PFS (p = 0.908), and OS (p = 0.832).

CONCLUSION

This study shows that with an appropriate design, including reduced doses, vulnerable older patients best tolerate chemotherapy when combined with anti-EGFR antibodies.

Impact of age and gender on the efficacy and safety of upfront therapy with panitumumab plus FOLFOX followed by panitumumab-based maintenance: a pre-specified subgroup analysis of the Valentino study

BACKGROUND

The safety and efficacy outcome of elderly metastatic colorectal cancer (mCRC) patients fit enough to receive combination chemotherapy plus biological agents is an issue of growing interest. Also, gender-specific differential toxicity and efficacy of anti-epidermal growth factor receptor (EGFR)-based upfront treatments need to be explored.

PATIENTS AND METHODS

Valentino was a multicenter, randomized, phase II trial, investigating two panitumumab-based maintenance strategies following first-line panitumumab plus FOLFOX in RAS wild-type mCRC patients. We carried out a subgroup analysis, aimed at assessing the differences in efficacy, safety and quality of life (QoL) according to age (<70 versus ≥70 years) and gender (male versus female). Efficacy endpoints were progression-free survival (PFS), overall survival (OS) and overall response rate (ORR); safety endpoints were rates of any grade and grade 3/4 adverse events (AEs).

RESULTS

No significant differences in terms of PFS, OS and ORR were observed between patients aged <70 or ≥70 years and the effect of the maintenance treatment arm on survival outcomes was similar in the two subgroups. The safety profile of both induction and maintenance treatment and the impact on QoL were similar in elderly and younger patients. No significant differences in PFS, OS, ORR or clinical benefit rate were observed according to gender. A significantly higher rate of overall grade 3/4 AEs (P = 0.008) and of grade 3/4 thrombocytopenia (P = 0.017), any grade and grade 3/4 neutropenia (P < 0.0001) and any grade conjunctivitis (P = 0.033) was reported in female as compared to male patients. Conversely, we reported a significantly higher incidence of any grade skin rash (P = 0.0007) and hypomagnesemia (P = 0.029) in male patients.

CONCLUSIONS

The upfront choice of an anti-EGFR-based doublet chemotherapy followed by a maintenance strategy represents a valuable option in RAS wild-type mCRC irrespective of gender and age, though a careful evaluation of patients to maximize the risk/benefit ratio is warranted.

Implementing anti-epidermal growth factor receptor (EGFR) therapy in metastatic colorectal cancer: challenges and future perspectives

Epidermal growth factor receptor (EGFR) inhibitors are valuable therapeutics in metastatic colorectal cancer (mCRC). Anti-EGFR monoclonal antibodies (MoAbs), such as cetuximab or panitumumab, in combination with chemotherapy are effective treatment options for patients with RAS and BRAF wild-type mCRC. Nevertheless, several issues are still open concerning the optimal use of anti-EGFR drugs in the continuum of care of mCRC. Novel approaches for increasing the efficacy of anti-EGFR therapies include better molecular selection of EGFR-dependent mCRC, intensification of chemotherapy, combination of anti-EGFR MoAbs and immune checkpoint inhibitors, and reintroduction of EGFR blockade or 'rechallenge' in selected patients who have previously responded to anti-EGFR MoAb therapy. An extensive translational research program was conducted in the Cetuximab After Progression in KRAS wIld-type colorectal cancer patients-Gruppo Oncologico dell' Italia Meridionale (CAPRI-GOIM) study with the aims of determining which subgroups of patients could benefit from the continuous inhibition of EGFR, from evaluating the role of liquid biopsy-based and its concordance with tissue-based molecular testing, and from investigating novel potential mechanisms of resistance to anti-EGFR therapies. In this review, we summarize the translational and clinical findings of the CAPRI-GOIM program in the context of the current knowledge of therapeutic strategies and of ongoing research on more appropriate uses of anti-EGFR therapies in RAS and BRAF wild-type mCRC patients.

Italian survey on cetuximab-based therapy of elderly patients with metastatic colorectal cancer

PURPOSE

There is no consensus on the use of cetuximab in elderly patients with metastatic colorectal cancer. To this end, a survey was carried in 17 Italian oncology centers.

METHODS

The centers answered a 29-item questionnaire structured as follows: (i) demographic characteristics; (ii) medical history; (iii) assessment of RAS/BRAF mutations and DPD/UGT polymorphism before treatment; (iv) treatment schemes and side effects; (v) geriatric assessment and customization of treatment.

RESULTS

One-third of patients are over 80 years old. The RAS/BRAF mutational status is not primarily evaluated by 17.6% of the centers, while DPD and UGT polymorphism is not evaluated by 82.4% and 76.5% of the centers. The most common therapeutic scheme is cetuximab/FOLFIRI and diarrhea is the main cause of suspension/reduction of treatment. The 70% of centers use systemic tetracyclines for skin toxicity. The 23.5% of the centers do not carry out any geriatric evaluation before the start of the therapy and those who perform it prefer the G8 (70.6%) and VES-13 (29.4%) scales.

CONCLUSIONS

Greater efforts should be made to improve the evaluation of the patient both about mutational and genetic procedures with geriatric evaluation. As for cetuximab in elderly patients, randomized studies are needed to provide guidance to physicians.

Pharmacotherapeutic considerations for elderly patients with colorectal cancer

Introduction: Oncology care in the elderly presents a dilemma. The majority of cancer cases are diagnosed in the elderly yet they are underrepresented in clinical trials. In addition to limited evidence-based medicine, the elderly is a heterogeneous population filled with pharmacotherapeutic challenges and barriers. Elderly metastatic colorectal cancer (mCRC) treatment decisions encompass these challenges.Areas covered: Treatment based solely on chronological age is an unacceptable practice. Physiologic factors such as function, cognition, comorbidities, polypharmacy, among others must be considered. Oncology guidelines emphasize using a geriatric assessment (GA) as opposed to traditional oncology performance status measures to best identify risks. Our review shines light on these issues as they pertain to elderly unresectable metastatic colorectal cancer (mCRC).Expert opinion: The practical use of GA tools in oncology remain to be determined. Current barriers are the lack of a consistent tool to unify decision-making, provider education, and evidence-based use/outcomes in specific cancers. mCRC antineoplastic data surrounding GAs are scarce, and current mCRC national treatment algorithms are not stratified to encompass GA-driven therapy. Therefore, providers lack clear guidance or practicality of use. We hope mCRC trial designs will abandon age cutoffs and instead place more focus on GAs for inclusion and outcomes.

Clinical characteristics and treatment propensity in elderly patients aged over 80 years with colorectal cancer

BACKGROUND/AIMS

Elderly patients (≥ 80 years) with colorectal cancer (CRC) tend to avoid active treatment at the time of diagnosis despite of recent advances in treatment. The aim of this study was to determine treatment propensity of elderly patients aged ≥ 80 years with CRC in clinical practice and the impact of anticancer treatment on overall survival (OS).

METHODS

Medical charts of 152 elderly patients (aged ≥ 80 years) diagnosed with CRC between 1998 and 2012 were retrospectively reviewed. Patients' clinical characteristics, treatment modalities received, and clinical outcome were analyzed.

RESULTS

Their median age was 82 years (range, 80 to 98). Of 152 patients, 148 were assessable for the extent of the disease. Eighty-two of 98 patients with localized disease and 28 of 50 patients with metastatic disease had received surgery or chemotherapy or both. Surgery was performed in 79 of 98 patients with localized disease and 15 of 50 patients with metastatic disease. Chemotherapy was administered in only 24 of 50 patients with metastatic disease. Patients who received anticancer treatment according to disease extent showed significantly longer OS compared to untreated patients (localized disease, 76.2 months vs. 15.4 months, p = 0.000; metastatic disease, 9.9 months vs. 2.6 months, p = 0.001). Along with anticancer treatment, favorable performance status (PS) was associated with longer OS in multivariate analysis of clinical outcome.

CONCLUSION

Elderly patients aged ≥ 80 years with CRC tended to receive less treatment for metastatic disease. Nevertheless, anticancer treatment in patients with favorable PS was effective in prolonging OS regardless of disease extent.

A novel treatment approach for retinoblastoma by targeting epithelial growth factor receptor expression with a shRNA lentiviral system

OBJECTIVES

Non-invasive treatment options for retinoblastoma (RB), the most common malignant eye tumor among children, are lacking. Epithelial growth factor receptor (EGFR) accelerates cell proliferation, survival, and invasion of many tumors including RB. However, RB treatment by targeting EGFR has not yet been researched. In the current study, we investigated the effect of EGFR down-regulation on RB progression using shRNA lentiviral vectors.

MATERIALS AND METHODS

EGFR expression in Weri-Rb-1 cells was down-regulated by EGFR shRNA-bearing lentiviral vectors. Cell death, proliferation, cell cycle as well as invasion after EGFR down-regulation were determined. Further signaling pathway analysis was done by Western blot.

RESULTS

Our results revealed that EGFR shRNA could specifically down-regulate EGFR expression and down-regulation of this protein promoted cell death. Further analysis on cell cycle demonstrated that EGFR down-regulation also suppressed cell proliferation by arresting cells at G1 phase. Invasion analysis showed that EGFR down-regulation suppressed cell invasion and was correlated with alteration in the expression of matrix metalloproteinases 2 and 9. Further signaling pathway analysis revealed that EGFR down-regulation mediated RB progression was through PI3K/AKT/mTOR signaling pathway.

CONCLUSION

Our study revealed that EGFR down-regulation, through the PI3K/AKT/mTOR signaling pathway, could inhibit RB progression by promoting cell death while suppressing cell proliferation and invasion. The findings of our study indicated that down-regulation of EGFR using shRNA lentiviral vectors may offer a novel non-invasive treatment for RB.

Inclusion of elderly or frail patients in randomized controlled trials of targeted therapies for the treatment of metastatic colorectal cancer: A systematic review

Treatment of metastatic colorectal cancer (mCRC) has been modified since the launching of targeted therapies. Colorectal cancer (CRC) is common in elderly patients; their representation in randomized controlled trials (RCTs) is thus crucial. This study aimed to evaluate and quantify the inclusion of elderly/frail patients in RCTs of targeted therapies in mCRC. A systematic review using Medline, Scopus, Cochrane Database and ISI Web of Science was performed to identify all phase II/III RCTs of bevacizumab, cetuximab, panitumumab, regorafenib and aflibercept in mCRC until January 2015. Two reviewers independently performed studies selection, and data extraction. The protocol was registered in Prospero (CRD42015016163). Among 1,369, identified publications, 54 RCTs were selected. Nine RCTs (17%) excluded elderly patients; median age of the included population was <65years old in 50 RCTs (93%). Twenty RCTs (37%) excluded frail patients, and many RCTs excluded patients with uncontrolled hypertension or heart failure, patients treated with specific drugs (mainly anticoagulants), and patients with inadequate creatinine clearance. Elderly/frail patients are underrepresented in RCTs studying targeted therapies in mCRC, and those elderly patients included in RCTs do not reflect well the general elderly population with mCRC because of the exclusion criteria. RCTs results concerning targeted therapies can be inferred only to relatively healthy elderly subjects.

Clinical activity and tolerability of FOLFIRI and cetuximab in elderly patients with metastatic colorectal cancer in the CAPRI-GOIM first-line trial

BACKGROUND

In the cetuximab after progression in KRAS wild-type colorectal cancer patients (CAPRI) trial patients with metastatic colorectal cancer (mCRC) received 5-fluorouracil, folinic acid and irinotecan (FOLFIRI) and cetuximab in first line followed by 5-Fluorouracil, folinic acid, oxaliplatin (FOLFOX) with or without cetuximab until progression. Limited data are available on the efficacy and safety of anti-epidermal growth factor receptor (anti-EGFR) agents on elderly patients with mCRC. In the current study we evaluated the efficacy and safety of FOLFIRI plus cetuximab in age-defined subgroups.

METHODS

A post-hoc analysis was performed in CAPRI trial patients; outcomes (progression-free survival (PFS), overall response rate (ORR), safety) were analysed by age-groups and stratified according to molecular characterisation. 3 age cut-offs were used to define the elderly population (≥65; ≥70 and ≥75 years).

RESULTS

340 patients with mCRC were treated in first line with FOLFIRI plus cetuximab. Among those, 154 patients were >65 years, 86 >70 years and 35 >75 years. Next-generation sequencing (NGS) was performed in 182 patients. Among them, 87 patients were >65 years, 46 >70 and 17 >75. 104 of 182 patients were wild type (WT) for KRAS, NRAS, BRAF, PIK3CA genes. In the quadruple WT group, 51 patients were ≥65 years; 29 were ≥70; 9 were ≥75. Median PFS was similar within the age-subgroups in the intention-to-treat population, NGS cohort and quadruple WT patients, respectively. Likewise, ORR was not significantly different among age-subgroups in the 3 populations. Safety profile was acceptable and similarly reported among all age-groups, with the exception of grade ≥3 diarrhoea (55% vs 25%, p=0.04) and neutropaenia (75% vs 37%, p=0.03) in patients ≥75 years and grade ≥3 fatigue (31% vs 20%, p=0.01) in patients <75 years.

CONCLUSIONS

Tolerability of cetuximab plus FOLFIRI was acceptable in elderly patients. Similar ORR and PFS were observed according to age-groups. No differences in adverse events were reported among the defined subgroups with the exception of higher incidence of grade ≥3 diarrhoea and neutropaenia in patients ≥75 years and grade ≥3 fatigue in patients <75 years.

TRIAL REGISTRATION NUMBER

2009-014041-81.

Immunotherapy for the treatment of colorectal tumors: focus on approved and in-clinical-trial monoclonal antibodies

Colorectal cancer is considered a disease of the elderly population. Since the number of geriatric patients continues to rise, monoclonal antibody therapy is the most promising therapy in the recent research. Presently, the monoclonal antibodies most frequently used in the treatment of colorectal tumors are bevacizumab, cetuximab, panitumumab, and ramucirumab. Bevacizumab is a monoclonal antibody that acts on VEGF. Cetuximab and panitumumab act on EGFR. Ramucirumab binds directly to the ligand-binding pocket of VEGFR-2 to block the binding of VEGF-A, VEGF-C, and VEGF-D. These monoclonal antibodies, alone or in association with radiotherapy or chemotherapy, are presenting good results and are increasing patient survival, despite the side effects. Due to the limited number of molecules available, several studies are trying to develop new monoclonal antibodies for the treatment of colorectal tumors. Among those being studied, some recent molecules are in phase I and/or II trials and are yielding advantageous results, such as anti-DR5, anti-Fn14, anti-IGF-1R, anti-EGFR, anti-NRP1, and anti-A33 antibodies. This has been successful in reducing side effects and in treating nonresponsive patients.

Age-related systemic treatment and survival of patients with metachronous metastases from colorectal cancer

BACKGROUND

Although the spectrum of systemic treatment for metastatic colorectal cancer (mCRC) has widened, there is a paucity of evidence for the feasibility and optimal use of these systemic agents in elderly patients. The present study provides real world data on the age-related systemic treatment and survival of CRC patients with non-resectable metachronous metastases.

METHODS

All consecutive patients with non-resectable metastases from primary resected CRC were extracted from the Eindhoven area of the Netherlands Cancer Registry (NCR). Patients receiving palliative systemic therapy were enrolled (n = 385). Systemic treatment and survival were analyzed according to age at diagnosis of metastases.

RESULTS

Patients aged ≥75 years more often received first-line single-agent chemotherapy than their younger counterparts (63% vs. 32%, p < .0001). First-line single-agent chemotherapy was often prescribed without additional targeted therapy (78%). Advanced age (≥75 years) was associated with a lower probability of receiving all active cytotoxic agents compared to patients aged <60 years at time of diagnosis of metastases (odds ratio (OR) 0.2, 95% CI 0.10-0.77). In a multivariable Cox regression analysis with adjustment for age and other relevant prognostic factors, the total number of received systemic agents was the only predictor of death (hazard ratio (HR) 0.7, 95% CI 0.61-0.81).

CONCLUSION

The beneficial effect of treatment with all active systemic agents on survival (simultaneously or sequentially prescribed) should be taken into account when considering systemic therapy in patients with mCRC. In light of our results, future studies are warranted to clarify the role of potential targeted therapy in elderly mCRC patients, who are often not candidates for combination chemotherapy and treatment with all active cytotoxic agents.

Colorectal cancer care in elderly patients: Unsolved issues

Colorectal cancers are common in elderly patients. However, cancer screening is poorly used after 75. Elderly patients form a heterogeneous population with specific characteristics. Standards of care cannot therefore be transposed from young to elderly patients. Tumour resection is frequently performed but adjuvant chemotherapy is rarely prescribed as there are no clearly established standards of care. In a metastatic setting, recent phase III studies have demonstrated that doublet front-line chemotherapy provided no survival benefit. Moreover, several studies have established the benefit of bevacizumab in association with chemotherapy. There is a lack of evidence for the efficacy of anti-epidermal growth factor antibodies in elderly patients. Geriatric assessments could help to select the adequate treatment strategy for individual patients. Geriatric oncology is now the challenge we have to face, and more specific trials are needed.

Efficacy and Safety of Bevacizumab Combined With Fluoropyrimidine Monotherapy for Unfit or Older Patients With Metastatic Colorectal Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

Whether bevacizumab represents a feasible option for the first-line treatment of unfit and elderly patients with metastatic colorectal cancer (mCRC) remains controversial. The present systematic review and meta-analysis evaluated the efficacy and safety data of bevacizumab combined with first-line fluoropyrimidine monochemotherapy for these complex patients.

PATIENTS AND METHODS

A systematic search of the published data was conducted through May 31, 2016. The random-effects model was used to combine the effect estimates and the I² index to quantify the between-study heterogeneity unexplained by sampling error.

RESULTS

We included 3 randomized controlled trials, 4 single-arm phase II trials, and 1 prospective cohort study in the present meta-analysis (n = 782). The monochemotherapy administered was capecitabine in 531 patients (67.9%) and 5-fluorouracil in 251 (32.1%); 500 (63.9%) also received bevacizumab. The median age was 75 years, 441 patients (56.4%) were men, and the Eastern Cooperative Oncology Group performance status was 0 to 1 in 684 patients (87.7%). The combination with bevacizumab produced advantages in terms of both progression-free survival (hazard ratio, 0.52; 95% confidence interval, 0.43-0.64; P < .00001; I² = 0%) and overall survival (HR, 0.79; 95% CI, 0.64-0.98; P = .03; I² = 0%). The pooled effect estimates of the randomized controlled trials have been previously reported. As expected, all-grade hypertension (27% vs. 4.9%), bleeding (24% vs. 6.4%), thromboembolic events (10% vs. 5%), and proteinuria (25.6% vs. 8.2%) were more frequent in the bevacizumab combination group.

CONCLUSION

Adding bevacizumab to first-line fluoropyrimidine monochemotherapy significantly improved progression-free and overall survival in unfit and elderly patients with mCRC, with a manageable safety profile and no unexpected toxicities.