Metastatic colorectal cancer (mCRC) is mainly a disease of elderly, however, geriatric population is underrepresented in clinical trials. Patient registries represent a tool to assess and follow ...treatment outcomes in this patient population. The aim of the study was with the help of the patients' register to determine the safety and efficacy of bevacizumab plus chemotherapy in elderly patients who had previously untreated metastatic colorectal cancer.
The registry of patients with mCRC was designed to prospectively evaluate the safety and efficacy of bevacizumab-containing chemotherapy as well as selection of patients in routine clinical practice. Patient baseline clinical characteristics, pre-specified bevacizumab-related adverse events, and efficacy data were collected, evaluated and compared according to the age categories.
Between January 2008 and December 2010, 210 patients with mCRC (median age 63, male 61.4%) started bevacizumab-containing therapy in the 1(st) line setting. Majority of the 210 patients received irinotecan-based chemotherapy (68%) as 1(st) line treatment and 105 patients (50%) received bevacizumab maintenance therapy. Elderly (≥ 70 years) patients presented 22.9% of all patients and they had worse performance status (PS 1/2, 62.4%) than patients in < 70 years group (PS 1/2, 35.8%). Difference in disease control rate was mainly due to inability to assess response in elderly group (64.6% in elderly and 77.8% in < 70 years group, p = 0.066). The median progression free survival was 10.2 (95% CI, 6.7-16.2) and 11.3 (95% CI, 10.2-12.6) months in elderly and < 70 years group, respectively (p = 0.58). The median overall survival was 18.5 (95% CI, 12.4-28.9) and 27.4 (95% CI, 22.7-31.9) months for elderly and < 70 years group, respectively (p = 0.03). Three-year survival rate was 26% and 37.6% in elderly vs. < 70 years group (p = 0.03). Overall rates of bevacizumab-related adverse events were similar in both groups: proteinuria 21/22 %, hypertension 25/19 %, haemorrhage 2/4 % and thromboembolic events 10/6 %, for elderly and < 70 years group, respectively.
In routine clinical practice, the combination of bevacizumab and chemotherapy is effective and well-tolerated regimen in elderly patients with metastatic colorectal cancer.
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e15546
Background: A phase IV non-interventional study was performed from 2013 till 2018 including 650 patients with primary aim to assess KRAS, NRAS and BRAF mutational status in ...Slovenian population with metastatic colorectal carcinoma (mCRC) suitable for first-line treatment. The evaluation of decisions for first-line treatment regarding the biomarkers status and assessing the possible impact of the time period of the biomarker status analysis report on the treatment decision were also incorporated in the analysis. The molecular analyses for KRAS and NRAS gene mutations were performed on exons 2, 3 and 4, and for BRAF gene mutations on exon 15. The first line systemic treatment options for RAS (KRAS/NRAS) wild type (wt) and mutated type (mt) mCRC subjects were as follows: chemotherapy - Fluoropyrimidine based systemic therapy combined with oxaliplatin and/or irinotecan with/without VEGF inhibitor bevacizumab and for RAS wt subjects, with/without EGFR inhibitors, cetuximab or panitumumab. Methods: To indicate the degree of certainty of KRAS, NRAS and BRAF status frequency as being wild type or mutant type 95% confidence interval was calculated. Results: The KRAS/NRAS/BRAF mutation rates were as follows - The distribution of subjects with KRAS mutated and wild-type tumors, was almost equal, 48.8% and 47.9% respectively. Eighty nine percent of the subjects had NRAS wild type tumours and 86.1% had BRAF wild type tumours. The most frequently used treatment regardless the biomarkers status and in accordance with the treatment guidelines was bevacizumab based combination therapy (53.1%). The EGFR inhibitor (cetuximab or panitumumab) based combination therapy was used in one third of mCRC subjects (30.9%), all with mCRC RAS wt. The time period from the initial presentation of the patient until the biomarker status analysis report was two weeks. Conclusions: With this study, we have proven that the distribution of the mutations in exons 2-4 of KRAS and NRAS genes and exon 15 in the BRAF gene in the Slovenian population with metastatic colorectal cancer matches historical data. Based on this, we conclude that the treatment decision in Slovenian population with metastatic colorectal carcinoma should be in the accordance with international treatment guidelines and on evidence based medicine. The molecular analysis performed at the Institute of Oncology Ljubljana was providing necessary biomarkers status report in an acceptable time that didn’t affect the treatment decision or delay the needed cancer treatment.
KRAS mutation status in codons 12 and 13 is recognized as a predictive factor for resistance to anti-EGFR monoclonal antibodies. Despite having a wild type KRAS (wt-KRAS), not all patients with ...wt-KRAS respond to anti-EGFR antibody treatment. Additional mechanisms of resistance may activate mutations of the other main EGFR effectors pathway. Consequently, other molecular markers in colorectal cancer are needed to be evaluated to predict the response to therapy.
In this retrospective study, objective responses (OR), time to progression (TTP), overall survival (OS) were analyzed in 176 metastatic colorectal cancer (mCRC) patients treated with first-line chemotherapy in combination with monoclonal antibodies in respect of KRAS status in codons 12 and 13 and BRAF mutational status.
The KRAS mutations were found in 63 patients (35.8 %), the KRAS mutation in codon 12 in 53 patients (30.1%) and the KRAS mutation in codon 13 in 10 patients (5.7%). The BRAF V600E mutation was detected in 13 of 176 patients (7.4%). In the subgroup of mCRC patients having wt-KRAS and wild type BRAF (wt-BRAF), the objective response rates were higher (OR 54.0% ,CR 14.7%, PR 39.3%) than in the patients with wt-KRAS and mt-BRAF (OR 38.5%,CR 15.4%, PR 23.1%), the difference was not statistically significant (p= 0.378). Median OS in patients with wt-KRAS wt-BRAF, and in patients with wt-KRAS mt-BRAF, was 107.4 months and 45 months, respectively. The difference was statistically significant (p= 0.042). TTP in patients with wt-KRAS wt-BRAF, and in patients with wt-KRAS mt-BRAF, was 16 months and 12 months, respectively. The difference was not statistically significant (p= 0.558).
Patients with BRAF V600E mutation have statistically significantly worse prognosis than the patients with wt-BRAF and progress earlier during treatment. The definitive role of the BRAF V600E mutation as a prognostic and predictive factor for the response to anti-EGFR monoclonal antibodies needs to be analyzed in large prospective clinical studies.
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