Demetris Papamichael

Effects of KRAS, BRAF, NRAS, and PIK3CA mutations on the efficacy of cetuximab plus chemotherapy in chemotherapy-refractory metastatic colorectal cancer: a retrospective consortium analysis

BACKGROUND Following the discovery that mutant KRAS is associated with resistance to anti-epidermal growth factor receptor (EGFR) antibodies, the tumours of patients with metastatic colorectal cancer are now profiled for seven KRAS mutations before receiving cetuximab or panitumumab. However, most patients with KRAS wild-type tumours still do not respond. We studied the effect of other downstream mutations on the efficacy of cetuximab in, to our knowledge, the largest cohort to date of patients with chemotherapy-refractory metastatic colorectal cancer treated with cetuximab plus chemotherapy in the pre-KRAS selection era. METHODS 1022 tumour DNA samples (73 from fresh-frozen and 949 from formalin-fixed, paraffin-embedded tissue) from patients treated with cetuximab between 2001 and 2008 were gathered from 11 centres in seven European countries. 773 primary tumour samples had sufficient quality DNA and were included in mutation frequency analyses; mass spectrometry genotyping of tumour samples for KRAS, BRAF, NRAS, and PIK3CA was done centrally. We analysed objective response, progression-free survival (PFS), and overall survival in molecularly defined subgroups of the 649 chemotherapy-refractory patients treated with cetuximab plus chemotherapy. FINDINGS 40.0% (299/747) of the tumours harboured a KRAS mutation, 14.5% (108/743) harboured a PIK3CA mutation (of which 68.5% [74/108] were located in exon 9 and 20.4% [22/108] in exon 20), 4.7% (36/761) harboured a BRAF mutation, and 2.6% (17/644) harboured an NRAS mutation. KRAS mutants did not derive benefit compared with wild types, with a response rate of 6.7% (17/253) versus 35.8% (126/352; odds ratio [OR] 0.13, 95% CI 0.07-0.22; p<0.0001), a median PFS of 12 weeks versus 24 weeks (hazard ratio [HR] 1.98, 1.66-2.36; p<0.0001), and a median overall survival of 32 weeks versus 50 weeks (1.75, 1.47-2.09; p<0.0001). In KRAS wild types, carriers of BRAF and NRAS mutations had a significantly lower response rate than did BRAF and NRAS wild types, with a response rate of 8.3% (2/24) in carriers of BRAF mutations versus 38.0% in BRAF wild types (124/326; OR 0.15, 95% CI 0.02-0.51; p=0.0012); and 7.7% (1/13) in carriers of NRAS mutations versus 38.1% in NRAS wild types (110/289; OR 0.14, 0.007-0.70; p=0.013). PIK3CA exon 9 mutations had no effect, whereas exon 20 mutations were associated with a worse outcome compared with wild types, with a response rate of 0.0% (0/9) versus 36.8% (121/329; OR 0.00, 0.00-0.89; p=0.029), a median PFS of 11.5 weeks versus 24 weeks (HR 2.52, 1.33-4.78; p=0.013), and a median overall survival of 34 weeks versus 51 weeks (3.29, 1.60-6.74; p=0.0057). Multivariate analysis and conditional inference trees confirmed that, if KRAS is not mutated, assessing BRAF, NRAS, and PIK3CA exon 20 mutations (in that order) gives additional information about outcome. Objective response rates in our series were 24.4% in the unselected population, 36.3% in the KRAS wild-type selected population, and 41.2% in the KRAS, BRAF, NRAS, and PIK3CA exon 20 wild-type population. INTERPRETATION While confirming the negative effect of KRAS mutations on outcome after cetuximab, we show that BRAF, NRAS, and PIK3CA exon 20 mutations are significantly associated with a low response rate. Objective response rates could be improved by additional genotyping of BRAF, NRAS, and PIK3CA exon 20 mutations in a KRAS wild-type population. FUNDING Belgian Federation against Cancer (Stichting tegen Kanker).

ESMO consensus guidelines for the management of patients with metastatic colorectal cancer.

Colorectal cancer (CRC) is one of the most common malignancies in Western countries. Over the last 20 years, and the last decade in particular, the clinical outcome for patients with metastatic CRC (mCRC) has improved greatly due not only to an increase in the number of patients being referred for and undergoing surgical resection of their localised metastatic disease but also to a more strategic approach to the delivery of systemic therapy and an expansion in the use of ablative techniques. This reflects the increase in the number of patients that are being managed within a multidisciplinary team environment and specialist cancer centres, and the emergence over the same time period not only of improved imaging techniques but also prognostic and predictive molecular markers. Treatment decisions for patients with mCRC must be evidence-based. Thus, these ESMO consensus guidelines have been developed based on the current available evidence to provide a series of evidence-based recommendations to assist in the treatment and management of patients with mCRC in this rapidly evolving treatment setting.

Treatment of the elderly colorectal cancer patient: SIOG expert recommendations

Colorectal cancer (CRC) is one of the commonest malignancies of Western countries, with approximately half the incidence occurring in patients >70 years of age. Elderly CRC patients, however, are understaged, undertreated and underrepresented in clinical trials. The International Society of Geriatric Oncology created a task force with a view to assessing the potential for developing guidelines for the treatment of elderly (geriatric) CRC patients. A review of the evidence presented by the task force members confirmed the paucity of clinical trial data in elderly people and the lack of evidence-based guidelines. However, recommendations have been proposed on the basis of the available data and on the emerging evidence that treatment outcomes for fit, elderly CRC patients can be similar to those of younger patients. It is hoped that these will pave the way for formal treatment guidelines based upon solid scientific evidence in the future.

A double-blind, randomised, placebo-controlled phase III intergroup study of gefitinib in patients with advanced NSCLC, non-progressing after first line platinum-based chemotherapy (EORTC 08021/ILCP 01/03)

BACKGROUND EORTC study 08021/ILCP 01/03 evaluated the role of consolidation gefitinib, an oral tyrosine kinase inhibitor (TKI), administered in patients with advanced non-small cell lung cancer (NSCLC), not progressing following standard 1st-line chemotherapy. METHODS Patients with advanced NSCLC, not-progressing after four cycles of platinum-based chemotherapy, were randomised to receive either gefitinib 250mg/d or matched placebo until progression or unacceptable toxicity. The primary end-point was overall survival (OS). Secondary end-points were progression-free survival (PFS) and toxicity. The study was powered to detect a 28% increase in OS from a median of 11-14.1months (HR=0.78) and planned to randomise 598 patients to observe 514 deaths. RESULTS After inclusion of 173 patients, the trial was prematurely closed due to low accrual. Baseline characteristics for gefitinib (n=86) and placebo (n=87) arms were well balanced. After a median follow up of 41months, the difference in median OS in the gefitinib and placebo arms was not statistically significant (10.9 and 9.4months, HR 0.83 [95% confidence interval (95% CI) 0.60-1.15]; p=0.2). The difference in median PFS significantly favoured gefitinib (4.1 and 2.9months, HR=0.61, [95% CI 0.45, 0.83]), p=0.0015). Adverse events reported in more than 10% of patients were rash (47% with gefitinib versus 13% with placebo) and diarrhoea (34% with gefitinib versus13% with placebo). CONCLUSIONS Despite its premature closure, this trial confirms previous evidence that consolidation gefitinib is safe and improves PFS. However, no difference in OS was observed in this study (NCT00091156).

Adjuvant Fluorouracil, Leucovorin, and Oxaliplatin in Stage II to III Colon Cancer: Updated 10-Year Survival and Outcomes According to BRAF Mutation and Mismatch Repair Status of the MOSAIC Study

PURPOSE The MOSAIC (Multicenter International Study of Oxaliplatin/Fluorouracil/Leucovorin in the Adjuvant Treatment of Colon Cancer) study has demonstrated 3-year disease-free survival (DFS) and 6-year overall survival (OS) benefit of adjuvant oxaliplatin in stage II to III resected colon cancer. This update presents 10-year OS and OS and DFS by mismatch repair (MMR) status and BRAF mutation. METHODS Survival actualization after 10-year follow-up was performed in 2,246 patients with resected stage II to III colon cancer. We assessed MMR status and BRAF mutation in 1,008 formalin-fixed paraffin-embedded specimens. RESULTS After a median follow-up of 9.5 years, 10-year OS rates in the bolus/infusional fluorouracil plus leucovorin (LV5FU2) and LV5FU2 plus oxaliplatin (FOLFOX4) arms were 67.1% versus 71.7% (hazard ratio [HR], 0.85; P = .043) in the whole population, 79.5% versus 78.4% for stage II (HR, 1.00; P = .980), and 59.0% versus 67.1% for stage III (HR, 0.80; P = .016) disease. Ninety-five patients (9.4%) had MMR-deficient (dMMR) tumors, and 94 (10.4%) had BRAF mutation. BRAF mutation was not prognostic for OS (P = .965), but dMMR was an independent prognostic factor (HR, 2.02; 95% CI, 1.15 to 3.55; P = .014). HRs for DFS and OS benefit in the FOLFOX4 arm were 0.48 (95% CI, 0.20 to 1.12) and 0.41 (95% CI, 0.16 to 1.07), respectively, in patients with stage II to III dMMR and 0.50 (95% CI, 0.25 to 1.00) and 0.66 (95% CI, 0.31 to 1.42), respectively, in those with BRAF mutation. CONCLUSION The OS benefit of oxaliplatin-based adjuvant chemotherapy, increasing over time and with the disease severity, was confirmed at 10 years in patients with stage II to III colon cancer. These updated results support the use of FOLFOX in patients with stage III disease, including those with dMMR or BRAF mutation.

Treatment of colorectal cancer in older patients. International Society of Geriatric Oncology (SIOG) consensus recommendations 2013

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in Europe and worldwide, with the peak incidence in patients >70 years of age. However, as the treatment algorithms for the treatment of patients with CRC become ever more complex, it is clear that a significant percentage of older CRC patients (>70 years) are being less than optimally treated. This document provides a summary of an International Society of Geriatric Oncology (SIOG) task force meeting convened in Paris in 2013 to update the existing expert recommendations for the treatment of older (geriatric) CRC patients published in 2009 and includes overviews of the recent data on epidemiology, geriatric assessment as it relates to surgery and oncology, and the ability of older CRC patients to tolerate surgery, adjuvant chemotherapy, treatment of their metastatic disease including palliative chemotherapy with and without the use of the biologics, and finally the use of adjuvant and palliative radiotherapy in the treatment of older rectal cancer patients. An overview of each area was presented by one of the task force experts and comments invited from other task force members.

Biomarkers of benefit from cetuximab-based therapy in metastatic colorectal cancer: interaction of EGFR ligand expression with RAS/RAF, PIK3CA genotypes

BackgroundMore than half of patients with KRAS-wild type advanced colorectal cancer (CRC) fail anti-EGFR monoclonal antibodies. We studied EGFR-axis messenger RNA (mRNA) expression and RAS, RAF, PIK3CA mutations in order to identify additional biomarkers of cetuximab efficacy.MethodsPreviously genotyped (KRAS, NRAS, BRAF, PIK3CA mutations) formalin-fixed paraffin-embedded tumour biopsies of 226 cetuximab-treated CRC patients (1st to 3rd line therapy) were assessed for mRNA expression of epidermal growth factor receptor (EGFR) and its ligands EGF, Transofrming Growth Factor-a (TGFA), Amphiregulin (AREG) and Epiregulin (EREG) with real time quantitative PCR. Mutations were detected in 72 (31.9%) tumours for KRAS, in 6 (2.65%) for BRAF, in 7 (3.1%) for NRAS and in 37 (16.4%) for PIK3CA.ResultsOnly PIK3CA mutations occasionally coexisted with other gene mutations. In univariate analysis, prognostic significance for survival ( from metastases until death) was seen for BRAF mutations (Hazard Ratio HR 8.1, 95% CI 3.4-19), codon 12-only KRAS mutations (HR 1.62, 95% CI 1.1-2.4), high AREG mRNA expression only in KRAS wild type CRC (HR 0.47, 95% CI 0.3-0.7) and high EREG mRNA expression irrespective of KRAS mutation status (HR 0.45, 95% CI 0.28-0.7). EREG tumoural mRNA expression was significantly associated with a 2.26-fold increased likelihood of objective response to cetuximab therapy (RECIST 1.1). In multivariate analysis, favourable predictive factors were high AREG mRNA in KRAS wild type tumours, high EREG mRNA, low Ephrin A2 receptor mRNA. Cetuximab-treated patients with AREG-low KRAS wild type CRC fared very poorly, their survival being similar to KRAS mutant CRC. Patients with KRAS codon 13 or other non-codon 12 mutations had a median survival (30 months, 95% CI 20–35) similar to that of patients with KRAS wild-type (median survival 29 months, 95% CI 25–35), in contrast to patients with KRAS codon 12 mutations who fared worse (median survival 19 months, 95% CI 15–26).ConclusionsBRAF and codon 12 KRAS mutations predict for adverse outcome of CRC patients receiving cetuximab. AREG mRNA reflects EGFR signalling in KRAS wild type tumours, predicting for cetuximab efficacy when high and failure when low. EREG may have a prognostic role independent of KRAS mutation.

EORTC Elderly Task Force experts’ opinion for the treatment of colon cancer in older patients

As a result of an increasing life expectancy, the incidence of colon cancer in the older population is rising. As a consequence oncologists and their older patients commonly face the dilemma of whether or not to give/receive treatment for colon cancer. However, the paucity of large, well conducted prospective trials makes it difficult to provide evidence-based clinical recommendations for these patients. The current evidence supports the safety and efficacy of treatment for colon cancer in fit older patients and demonstrates that treatment outcome can be similar to that of their younger counterparts. However, it should be noted that these data are derived from retrospective studies which are likely to suffer from selection bias. Despite a growing body of data, further work is still needed to establish optimal strategies to care for this special population and prospective specific trials for older colon cancer patients are clearly needed.

Treatment of colorectal cancer in older patients

Colorectal cancer (CRC) largely affects older individuals; almost half of cases occur in patients >75 years old. The incidence increases with advancing age, doubling every 7 years in patients aged ≥50 years. The medical and societal burdens of CRC will probably worsen over the coming decades as the number of older individuals (>70) continues to grow. No evidence-based guidelines are available for this age group, as older patients with CRC are generally excluded from randomized clinical trials and the fit ones who are recruited are not representative of the general elderly population. When feasible, surgery is the most successful treatment option for eradicating the primary lesion, as well as any metastases. The operative risk under elective conditions is not markedly different in older than in younger patients; however, the acute setting is to be avoided as it is associated with high operative death rates. Well-selected older patients can tolerate chemotherapy, but benefits need to be balanced against potentially limited life expectancy and reduced quality of life. The use of combination chemotherapy is an area of much controversy, but this treatment should not necessarily be withheld because of the age of the patient. Careful monitoring of toxicities and early intervention is essential in older patients undergoing chemotherapy.

Induction chemotherapy with cisplatin, epirubicin, and paclitaxel (CEP), followed by concomitant radiotherapy and weekly paclitaxel for the management of locally advanced nasopharyngeal carcinoma. A Hellenic Cooperative Oncology Group phase II study.

Background:Clinical research on the treatment of nasopharyngeal cancer (NPC) has been focused primarily on the reduction of incidence of the development of distant metastases as well as the improvement of locoregional control.Patients and Methods:Untreated patients with stage IIB–IVB nonmetastatic NPC were treated with three cycles of induction chemotherapy (IC) consisting of epirubicin 75 mg/m2 followed by paclitaxel 175 mg/m2 as 3-h infusion on day 1 and cisplatin 75 mg/m2 on day 2 every 3 weeks, followed by concomitant radiation therapy (70 Gy), and chemotherapy (CCRT) with weekly paclitaxel 60 mg/m2.Results:From November 1999 until April 2003, 47 patients entered the study. Complete response rate post IC therapy was 15%, which was raised to 66% after the completion of CCRT. The most frequent side effect from IC was myelotoxicity (55%), whereas stomatitis and xerostomia were the most pronounced (grade 3, 4) toxicities during CCRT. The presence of Epstein-Barr virus (EBV) was detected either by in situ hybridization in tumor tissue sections or by polymerase chain reaction in the peripheral blood in 37 out of 46 patients tested (80%). All three histological types were associated with the presence of EBV. After a median follow-up of 23.5 months, median time to treatment failure was 17.9 months, whilst median survival has not been reached yet.Conclusion:IC followed by CCRT is feasible and produces durable complete responses in the majority of patients with NPC. The case detection rate of EBV in this study appears to be similar to that reported from endemically infected regions.Hintergrund:Die klinische Forschung in der Behandlung des Nasopharynxkarzinoms (NPC) fokussiert vorrangig auf die Reduktion von Fernmetastasen und die Verbesserung der lokoregionären Kontrolle.Patienten und Methodik:Unbehandelte Patienten mit nicht metastasiertem NPC wurden mit drei Zyklen Induktionschemotherapie (IC), bestehend aus Epirubicin 75 mg/m2 und Paclitaxel 175 mg/m2 als 3-stündige Infusion an Tag 1 sowie Cisplatin 75 mg/m2 an Tag 2 alle 3 Wochen, gefolgt von simultaner Radiochemotherapie (RCT) mit 70 Gy und 60 mg/m2 Paclitaxel wöchentlich, behandelt.Ergebnisse:Von November 1999 bis April 2003 wurden 47 Patienten in die Studie aufgenommen. Die Rate an kompletten Remissionen nach IC betrug 15% und konnte nach Abschluss der konsekutiven RCT auf 66% angehoben werden. Die häufigste Nebenwirkung der IC war Myelotoxizität (55%), der RCT dagegen Stomatitis und Xerostomie (Grad 3, 4). Eine Epstein-Barr-Virus-(EBV-)Positivität wurde durch In-situ-Hybridisierung in Tumorgewebe oder Polymerase-Kettenreaktion im peripheren Blut in 37 von 46 Fällen (80%) nachgewiesen. Alle drei histologischen Typen gingen mit EBV-Positivität einher. Bei einer medianen Nachbeobachtungszeit von 23,5 Monaten betrug die mediane Zeit bis zum Therapieversagen 17,9 Monate; das mediane Überleben hingegen ist noch nicht determiniert.Schlussfolgerung:IC, gefolgt von RCT, geht bei der Mehrzahl der Patienten mit NPC mit lang anhaltenden Komplettremissionen einher. Die Kontaminationsrate mit EBV in dieser Studie ähnelt der endemisch betroffener Regionen.