Per Pfeiffer

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).

Phase III Trial of Cetuximab With Continuous or Intermittent Fluorouracil, Leucovorin, and Oxaliplatin (Nordic FLOX) Versus FLOX Alone in First-Line Treatment of Metastatic Colorectal Cancer: The NORDIC-VII Study

PURPOSE The NORDIC-VII multicenter phase III trial investigated the efficacy of cetuximab when added to bolus fluorouracil/folinic acid and oxaliplatin (Nordic FLOX), administered continuously or intermittently, in previously untreated metastatic colorectal cancer (mCRC). The influence of KRAS mutation status on treatment outcome was also investigated. PATIENTS AND METHODS Patients were randomly assigned to receive either standard Nordic FLOX (arm A), cetuximab and FLOX (arm B), or cetuximab combined with intermittent FLOX (arm C). Primary end point was progression-free survival (PFS). Overall survival (OS), response rate, R0 resection rate, and safety were secondary end points. RESULTS Of the 571 patients randomly assigned, 566 were evaluable in intention-to-treat (ITT) analyses. KRAS and BRAF mutation analyses were obtained in 498 (88%) and 457 patients (81%), respectively. KRAS mutations were present in 39% of the tumors; 12% of tumors had BRAF mutations. The presence of BRAF mutations was a strong negative prognostic factor. In the ITT population, median PFS was 7.9, 8.3, and 7.3 months for the three arms, respectively (not significantly different). OS was almost identical for the three groups (20.4, 19.7, 20.3 months, respectively), and confirmed response rates were 41%, 49%, and 47%, respectively. In patients with KRAS wild-type tumors, cetuximab did not provide any additional benefit compared with FLOX alone. In patients with KRAS mutations, no significant difference was detected, although a trend toward improved PFS was observed in arm B. The regimens were well tolerated. CONCLUSION Cetuximab did not add significant benefit to the Nordic FLOX regimen in first-line treatment of mCRC.

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.

Radiation-induced brachial plexopathy: Neurological follow-up in 161 recurrence-free breast cancer patients

PURPOSE The purpose was to assess the incidence and clinical manifestations of radiation-induced brachial plexopathy in breast cancer patients, treated according to the Danish Breast Cancer Cooperative Group protocols. METHODS AND MATERIALS One hundred and sixty-one recurrence-free breast cancer patients were examined for radiation-induced brachial plexopathy after a median follow-up period of 50 months (13-99 months). After total mastectomy and axillary node sampling, high-risk patients were randomized to adjuvant therapy. One hundred twenty-eight patients were treated with postoperative radiotherapy with 50 Gy in 25 daily fractions over 5 weeks. In addition, 82 of these patients received cytotoxic therapy (cyclophosphamide, methotrexate, and 5-fluorouracil) and 46 received tamoxifen. RESULTS Five percent and 9% of the patients receiving radiotherapy had disabling and mild radiation-induced brachial plexopathy, respectively. Radiation-induced brachial plexopathy was more frequent in patients receiving cytotoxic therapy (p = 0.04) and in younger patients (p = 0.04). The clinical manifestations were paraesthesia (100%), hypaesthesia (74%), weakness (58%), decreased muscle stretch reflexes (47%), and pain (47%). CONCLUSION The brachial plexus is more vulnerable to large fraction size. Fractions of 2 Gy or less are advisable. Cytotoxic therapy adds to the damaging effect of radiotherapy. Peripheral nerves in younger patients seems more vulnerable. Radiation-induced brachial plexopathy occurs mainly as diffuse damage to the brachial plexus.

Dose-response relationship of epirubicin in the treatment of postmenopausal patients with metastatic breast cancer: a randomized study of epirubicin at four different dose levels performed by the Danish Breast Cancer Cooperative Group.

PURPOSE To test for possible correlations between dose of single-drug epirubicin and efficacy/toxicity in postmenopausal women with metastatic breast cancer. The study also included analysis of a correlation between pharmacokinetic and pharmacodynamic parameters. PATIENTS AND METHODS Two hundred eighty-seven women were randomized to receive either 40, 60, 90, or 135 mg/m2 of epirubicin intravenously (IV) every 3 weeks. Treatment consisted of first-line cytotoxic therapy for metastatic disease. In patients with early progressive disease after either 40 or 60 mg/m2, dose escalation to 135 mg/m2 was performed. A full pharmacokinetic analysis was performed in 78 patients. RESULTS Among 263 eligible patients, an increase in response rate and time to progression was found with an increase in dose from 40 to 90 mg/m2, while no increase in efficacy was found from 90 to 135 mg/m2. Multivariate analysis, using the Cox proportional hazards model with time to progression as the end point, confirmed that epirubicin dose more than 60 mg/m2 was an independent prognostic covariate. Furthermore, a significant association was established between randomized dose and both hematologic and nonhematologic toxicity. No association between pharmacokinetic parameters and efficacy parameters was demonstrated. On the other hand, a significant correlation between pharmacokinetic parameters and both hematologic and nonhematologic toxicity was found. CONCLUSION An increase in dose of epirubicin from 40 to 90 mg/m2 is accompanied by increased efficacy. Further increases in dose do not yield increased efficacy. A positive correlation between epirubicin dose and toxicity, as well as a correlation between pharmacokinetic parameters and toxicity, was also established.

Lack of prognostic significance of epidermal growth factor receptor and the oncoprotein p185HER-2 in patients with systemically untreated non-small-cell lung cancer: an immunohistochemical study on cryosections.

The prognostic role of the epidermal growth factor receptor (EGFR) and the related receptor p185HER-2 in lung cancer is as yet undefined. We investigated the immunohistochemical expression of EGFR (monoclonal antibody R1; Amersham) and p185HER-2 (polyclonal antibody A485; Dako) in cryosections. A total of 186 unselected and systemically untreated patients with non-small-cell lung cancer (NSCLC) diagnosed and treated at Odense University Hospital, Denmark, were included. Median follow-up period was 66 months. EGFR and p185HER-2 was highly expressed in 55% and 26% of cases respectively. Expression of EGFR was independent of p185HER-2 expression. The expression of EGFR was higher in squamous cell carcinomas whereas the level of p185HER-2 staining was higher in adenocarcinomas. Expression of either or both receptors was not correlated with age, histological grading, stage and prognosis. We conclude that immunohistochemical detection of these growth factor receptors failed to demonstrate a prognostic significance in patients operated on for NSCLC.

Irradiation of bone metastases in breast cancer patients: a randomized study with 1 year follow-up

The results from a prospective randomized trial comparing two different radiation schedules for treatment of painful bone metastases in women with recurrent breast cancer are presented. A total of 217 patients with painful bone metastases were randomized to either 30 Grey (Gy) in ten fractions, five fractions a week (5F/W) or 15 Gy in three fractions 2F/W. The effect of treatment was evaluated by pain assessment, the radiological response and the degree of side-effects. The patients were rated at start of treatment and after 1, 3, 6 and 12 months. No difference between the two radiation regimes was found, neither in achieved pain relief, improvement in level of activity and medication, nor was there any difference in radiological response and side-effects from treatment. Both regimes resulted in a significant improvement in both pain score and level of activity 1 month after treatment, an improvement which persisted during the follow-up period. We conclude that 15 Gy given in three fractions 2F/W is as effective as 30 Gy in ten fractions 5F/W, but more convenient to the patient and of less cost to society.

Clinical trial enrollment, patient characteristics, and survival differences in prospectively registered metastatic colorectal cancer patients.

Trial accrual patterns were examined to determine whether metastatic colorectal cancer (mCRC) patients enrolled in trials are representative of a general cancer population concerning patient characteristics and survival.

Systemic cytotoxic therapy of basal cell carcinoma

Fifty-five cases of systemic, cytotoxic therapy of patients with basal cell carcinoma have been reported in 53 patients in the English literature since the first report in 1960. Cytotoxic therapy without cis-platinum was used in 28 cases, resulting in only one partial response. On the contrary, 17 out of 22 evaluable patients (77%) responded to systemic treatment with cis-platinum-containing regimens. In 10 patients (45%) complete disappearance of the tumor was noted. These patients survived for a median time of more than 22 months (range 4+ to 51+ months). Although the experience is limited, the use of cis-platinum-containing regimens seems justified in the rare instances of metastatic disease, or when local treatment fails. When the primary tumor is very large, pretreatment with cis-platinum alone or in combination might be of value.

Biweekly cetuximab and irinotecan as third-line therapy in patients with advanced colorectal cancer after failure to irinotecan, oxaliplatin and 5-fluorouracil

BACKGROUND Standard weekly cetuximab and irinotecan (CetIri) is an effective regimen in heavily pretreated patients with advanced colorectal cancer (ACRC). Inspired by a pharmacokinetic study demonstrating no differences between weekly and biweekly cetuximab, we present the results of 74 consecutive patients treated with biweekly CetIri. METHODS Biweekly CetIri schedule: cetuximab 500 mg/m(2), first course was given as a 120-min infusion followed 1 h later by irinotecan 180 mg/m(2) as a 30-min infusion. Subsequent courses of cetuximab were given in 60 min, immediately followed by irinotecan-resulting in an overall treatment time of 90 min. RESULTS All patients had ACRC resistant to 5-fluorouracil and irinotecan and 95% to oxaliplatin. Median age was 63 years, median performance status was 0. Median duration of therapy was 4.3 months. Response rate was 25%. Median progression-free survival and overall survival were 5.4 months and 8.9 months, respectively, comparable to own historical controls receiving weekly CetIri. Grade 3-4 toxicity was rare (skin 7%, nail 3%, diarrhoea 10%, fatigue 3%, neutropenia 9%). One patient experienced severe allergic reaction. CONCLUSION Salvage therapy with simplified biweekly CetIri is a convenient, effective and well-tolerated regimen in heavily pretreated patients with ACRC. A confirmatory phase II study is ongoing.