<?xml version="1.0" encoding="utf-8"?>
<recommendedContent xmlns="http://api.mspoke.com">
    <recommendedItem id="20100101_19_398"
                     title="ASCO GI: Gene Test, Nodes Predict Colon CA Recurrence Risk (CME/CE)"
                     score="0.012"
                     href="http://www.medpagetoday.com/MeetingCoverage/ASCOGI/tb/18301?impressionId=1265796437424"
                     
      &lt;p&gt;ORLANDO  --  An extended nodal examination and gene array test show promise for identifying patients at high risk of colorectal cancer recurrence in stage II disease, researchers reported at the Gastrointestinal Cancers Symposium.&lt;/p&gt;
&lt;p&gt;Across the range of recurrence scores, examination of at least 12 nodes was associated with about a 5% absolute decrease in the three-year risk of recurrence in resected stage II colon cancers, compared with the same recurrence score and examination of fewer nodes.&lt;/p&gt;
&lt;p&gt;Noting limitations of other tests and biomarkers developed to evaluate recurrence risk, the gene expression-derived recurrence score &quot;has a real chance to make its way into the clinical decision algorithm,&quot; said David Kerr, MD, of the University of Oxford in England.&lt;/p&gt;
&lt;p&gt;Both recurrence score and number of nodes examined were independent predictors of recurrence risk, but investigators found no association or interaction between the two parameters of risk assessment.&lt;/p&gt;
&lt;p&gt;&quot;The test gives us more information about individual patients about the likelihood of the cancer returning,&quot; said Kerr, who was an investigator in the study. &quot;I think the quality of the science underpinning it, the size of the sample, and the compelling statistics all combine to make this a potential winner.&quot;&lt;/p&gt;
&lt;p&gt;Another study reported at the meeting showed few tumor-related genetic characteristics to distinguish stage II colon cancer from stage III.&lt;/p&gt;
&lt;p&gt;Both studies involved use a 12-gene assay (Oncotype DX) validated for predicting recurrence risk in stage II colon cancer. Investigators in the QUASAR validation study used data from the trial to evaluate the prognostic value of nodal assessment combined with other parameters, including the 12-gene assay.&lt;/p&gt;
&lt;p&gt;The National Comprehensive Cancer Network (NCCN) clinical guidelines for stage II colon cancer include number of nodes examined as a prognostic factor, Richard Gray, PhD, of the University of Birmingham in England, and colleagues noted in a poster presentation.&lt;/p&gt;
&lt;p&gt;Records for 657 stage II patients randomized to surgery alone showed that the median number of nodes examined was 10, including fewer than six nodes in 19% of patients and &amp;#8805;12 nodes in 37%. Risk of recurrence was more closely associated with examination of fewer than eight nodes versus more (HR 1.77, &lt;em&gt;P&lt;/em&gt;&amp;lt;0.001) than with a cutoff point of 12 nodes (HR 1.38, &lt;em&gt;P&lt;/em&gt;=0.065). &lt;/p&gt;
&lt;p&gt;More nodes were examined in later than earlier years, the investigators found.&lt;/p&gt;
&lt;p&gt;In a model that included recurrence score derived from the gene assay and the 12-node threshold recommended by NCCN, both factors proved to be independent predictors of recurrence risk (&lt;em&gt;P&lt;/em&gt;=0.01, &lt;em&gt;P&lt;/em&gt;=0.05). Similar results emerged from models that incorporated mismatch repair (or microsatellite instability) and T stage.&lt;/p&gt;
&lt;p&gt;Across the range of recurrence scores, examination of &amp;#8805;12 nodes was associated with a 3% to 7% lower risk of recurrence compared with examination of fewer nodes (about 5% overall). The investigators concluded that both parameters should be included in assessment of recurrence risk after surgery for stage II colon cancer.&lt;/p&gt;
&lt;p&gt;The second study examined the 12-gene assay&apos;s ability to distinguish stage II from stage III colon cancer. Investigators evaluated the assay, pathologic markers, and expression of 375 different genes in 634 patients with stage II disease and 844 with stage III colon cancer.&lt;/p&gt;
&lt;p&gt;The data showed minimal differences in gene expression between the two stages of colon cancer.&lt;/p&gt;
&lt;p&gt;Five of the 375 genes differed significantly in their expression in stage II versus stage III cancer (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.05). Two tumor characteristics differed by stage, as stage II colon cancer was more likely to be mismatch repair-deficient (&lt;em&gt;P&lt;/em&gt;=0.04) and have mucinous histology (&lt;em&gt;P&lt;/em&gt;=0.007).&lt;/p&gt;
&lt;p&gt;The data also showed significant interaction of grade and stage (&lt;em&gt;P&lt;/em&gt;=0.005), and borderline significance for interactions of stage with T-stage, mismatch repair, and mucinous histology, reflecting prognostic value in stage II but not stage III disease.&lt;/p&gt;
&lt;p&gt;Overall, investigators in this second study found a &quot;striking similarity between stages for the recurrence score and the vast majority of genes analyzed.&quot;&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The studies were supported by Genomic Health.&lt;/p&gt;&lt;p&gt;Investigators in the studies included employees of Genomic Health.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_391"
                     title="Rare Genetic Deletion Linked to Morbid Obesity (CME/CE)"
                     score="0.009"
                     href="http://www.medpagetoday.com/Genetics/GeneralGenetics/tb/18286?impressionId=1265796437424"
                     
      &lt;p&gt;Missing sections of DNA may have a powerful impact on weight for a small segment of the population, researchers said.&lt;/p&gt;
&lt;p&gt;Nearly all teens and adults found to have a particular deletion of roughly 30-genes on chromosome 16p11.2 were obese  --  most morbidly so  --  with a body mass index of at least 40 kg/m&lt;sup&gt;2&lt;/sup&gt;, Philippe Froguel, MD, PhD, of Imperial College London, and colleagues reported in &lt;em&gt;Nature&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;While the variant appeared to explain only a small proportion of morbid obesity  --  0.7% in the study population  --  it was never present in healthy, normal-weight controls.&lt;/p&gt;
&lt;p&gt;&quot;Although the recent rise in obesity in the developed world is down to an unhealthy environment, with an abundance of unhealthy food and many people taking very little exercise, the difference in the way people respond to this environment is often genetic,&quot; Froguel said in a prepared statement.&lt;/p&gt;
&lt;p&gt;But with further findings like these, it may be possible to identify such individuals through genetic testing, he said.&lt;/p&gt;
&lt;p&gt;If so, &quot;We can then offer them appropriate support and medical interventions, such as the option of weight-loss surgery, to improve their long-term health,&quot; Froguel declared.&lt;/p&gt;
&lt;p&gt;Although researchers speculate that one in 20 cases of obesity may have a genetic cause, the genetic component remains largely elusive.&lt;/p&gt;
&lt;p&gt;Even accounting for such a small fraction of cases, the newly discovered 16p11.2 variant would be the second most frequent known genetic cause of obesity, Froguel&apos;s group said.&lt;/p&gt;
&lt;p&gt;Extensive genome-wide association studies have linked numerous single nucleotide polymorphisms (SNPs) to obesity, but added all together they account for only a small fraction of the known heritable component, the researchers said.&lt;/p&gt;
&lt;p&gt;&quot;The &apos;common disease, common variant&apos; hypothesis is increasingly coming under challenge,&quot; they wrote.&lt;/p&gt;
&lt;p&gt;Their team first identified the genetic deletion in teen and adults with learning difficulties or delayed development.&lt;/p&gt;
&lt;p&gt;Because the 31 individuals who had the nearly identical deletions of at least 593 kilobases at chromosome 16p11.2 in one copy of their DNA all had a BMI of over 30 kg/m&lt;sup&gt;2&lt;/sup&gt;, the researchers decided to dig a little deeper.&lt;/p&gt;
&lt;p&gt;&quot;Cohorts with extreme phenotypes that include obesity may be enriched for rare but very potent risk variants,&quot; making them easier to discover, they wrote.&lt;/p&gt;
&lt;p&gt;So they undertook a case-control study among 312 patients at three centers in Britain and France who presented with congenital malformations, developmental delay, or both, in addition to obesity.&lt;/p&gt;
&lt;p&gt;The same deletions were seen in 2.9% of these individuals.&lt;/p&gt;
&lt;p&gt;The function of the missing genes are not well known, but some have previously been associated with delayed development, autism, and schizophrenia.&lt;/p&gt;
&lt;p&gt;Notably, though, the frequency of deletion of these genes in the obese case-control cohort was &quot;appreciably higher&quot; than the less than 1% seen in the autism and other studies that didn&apos;t include obesity as an inclusion criteria, the researchers said.&lt;/p&gt;
&lt;p&gt;A second independent survey of genetic data at eight cytogenetic centers in France, Switzerland, and Estonia turned up a 0.6% rate among 3,947 people with developmental delay, malformations, or both, but who were not selected for obesity (&lt;em&gt;P&lt;/em&gt;=0.00022 versus the cohort selected for obesity).&lt;/p&gt;
&lt;p&gt;Analysis of those with the missing genes revealed an age-dependent link to weight: All four teens and adults were obese. Children were often obese (four of 15) or overweight (two of 15). Children under 2 years all had normal weight.&lt;/p&gt;
&lt;p&gt;So to see whether the deletion was independent of neurodevelopmental problems, Froguel&apos;s group examined genome-wide association study data from general population cohorts totaling 11,856 individuals along with 2,772 from childhood obesity and adult morbid obesity case-control studies, 931 in an extreme early-onset obesity study, and 141 who had bariatric weight-loss surgery.&lt;/p&gt;
&lt;p&gt;All adult carriers of the deletion were obese with the exception of one who was apparently diabetic. Each of the seven children and adolescents who carried the variant had a BMI in the top 0.1% for their age and gender.&lt;/p&gt;
&lt;p&gt;None had any reported developmental or cognitive problems. Four had reported hyperphagia with excessive hunger and food intake.&lt;/p&gt;
&lt;p&gt;Altogether, the 16p11.2 deletions predicted 29.8-fold elevated risk of obesity (&lt;em&gt;P&lt;/em&gt;=0.00000058) and 43.0-fold elevated risk of morbid obesity (&lt;em&gt;P&lt;/em&gt;=0.000000064) compared with lean or normal weight.&lt;/p&gt;
&lt;p&gt;By extrapolation, the researchers extrapolated that about 0.4% of all morbidly obese cases are attributable to an inherited 16p11.2 deletion, with 0.3% arising from a de novo deletion in the same genetic region.&lt;/p&gt;
&lt;p&gt;&quot;Although they may be heterogeneous in nature, these deletions are highly likely to be the causal variants,&quot; they wrote.&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The study was supported by &quot;Le Conseil Regional Nord Pas de Calais/FEDER&quot; along with various governmental and industry supporters for the various component studies.&lt;/p&gt;&lt;p&gt;The researchers reported no financial conflicts of interest.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_307"
                     title="Good Results in Poor-Risk Rectal Cancer (CME/CE)"
                     score="0.005"
                     href="http://www.medpagetoday.com/HematologyOncology/ColonCancer/tb/18169?impressionId=1265796437424"
                     
      &lt;p&gt;Patients with high-risk rectal cancer had high response and three-year survival rates on a regimen of preoperative chemotherapy, followed by standard chemoradiation and then surgical resection, according to results of a multicenter study.&lt;/p&gt;
&lt;p&gt;Three-fourths of patients had objective responses to neoadjuvant chemotherapy, increasing to 89% after chemoradiation, researchers reported online in &lt;em&gt;The Lancet Oncology&lt;/em&gt;.&lt;/p&gt;
&lt;p&gt;Additionally, 97% of patients who underwent surgery had microscopically clear surgical margins. At three years, 83% of patients remained alive, including almost 70% who were progression free.&lt;/p&gt;
&lt;p&gt;&quot;Intensification of systemic therapy with neoadjuvant combination chemotherapy before standard treatment is feasible in poor-risk, potentially operable rectal cancer, with acceptable safety and promising long-term outcomes,&quot; David Cunningham, MD, of the Royal Marsden Hospital in Sutton, England, and co-authors concluded.&lt;/p&gt;
&lt;p&gt;&quot;Future development of this multidisciplinary treatment strategy in randomized trials is warranted.&quot;&lt;/p&gt;
&lt;p&gt;Although surgery remains the primary and potentially curative therapy for localized rectal cancer, local recurrence rates as high as 40% have been reported with conventional resection.&lt;/p&gt;
&lt;p&gt;The introduction of standardized surgery and total mesorectal excision reduced local recurrence rates to less than 10%, which has been associated with improved survival, the authors noted.&lt;/p&gt;
&lt;p&gt;Preoperative radiotherapy and then chemoradiation further reduced the risk of local recurrence, but did not improve overall survival compared with surgery alone.&lt;/p&gt;
&lt;p&gt;Combination chemotherapy has led to higher response rates and progression-free survival compared with monotherapy for patients with advanced rectal cancer, the authors continued. Adjuvant chemotherapy containing oxaliplatin (Eloxatin) also has improved outcomes in resected colon cancer.&lt;/p&gt;
&lt;p&gt;Given that oxaliplatin-fluoropyrimidine combinations have become a preferred standard, investigators designed a clinical trial of high-risk rectal cancer to investigate preoperative treatment with oxaliplatin and capecitabine (Xeloda).&lt;/p&gt;
&lt;p&gt;A previous report involving the first 77 patients enrolled in the trial showed substantial tumor regression, rapid improvement in symptoms, and a high rate of clear surgical margins (&lt;em&gt;J Clin Oncol&lt;/em&gt; 2006; 24: 668-74).&lt;/p&gt;
&lt;p&gt;Nine treatment-related cardiac events occurred in eight of the 77 patients, prompting a protocol amendment to exclude patients with a recent history of clinically significant cardiac problems.&lt;/p&gt;
&lt;p&gt;The updated results comprised 105 patients, and only one cardiac event occurred after the change in eligibility criteria, the authors wrote.&lt;/p&gt;
&lt;p&gt;All of the patients had MRI-defined, poor-risk but nonmetastatic rectal cancer. Patients received four cycles of neoadjuvant chemotherapy over 12 weeks, followed by chemoradiotherapy consisting of a total radiation dose of 54 Gy administered over six weeks, plus daily capecitabine.&lt;/p&gt;
&lt;p&gt;After total mesorectal excision, patients received 12 weeks of adjuvant capecitabine.&lt;/p&gt;
&lt;p&gt;The primary endpoint was pathologic complete response, and median follow-up was 55 months.&lt;/p&gt;
&lt;p&gt;Radiologically confirmed response rates were 74% after neoadjuvant chemotherapy and 89% after chemoradiation. Of 97 patients who had surgery, 93 had microscopically clear margins, and 21 of 105 patients had pathologic complete responses.&lt;/p&gt;
&lt;p&gt;Three-year progression-free and overall survival were 68% and 83%, respectively. Among patients who had surgery, three-year, relapse-free survival was 74%.&lt;/p&gt;
&lt;p&gt;&quot;Our findings show the feasibility of neoadjuvant chemotherapy with capecitabine and oxaliplatin before chemoradiotherapy and total mesorectal excision, which accord with the initial results of this study,&quot; the authors declared.&lt;/p&gt;
&lt;p&gt;&quot;High radiological response rates to preoperative treatment were recorded, and the number of pathological complete responses surpassed the prespecified number needed to meet the primary objective of this trial.&quot;&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;The study was supported by England&apos;s National Health Service and sanofi-aventis.&lt;/p&gt;&lt;p&gt;Cunningham and co-author Niall Tebbutt disclosed relationships with Roche and sanofi-aventis.&lt;/p&gt;&lt;p&gt;Co-author Ian Chau disclosed relationships with Roche and sanofi-aventis.&lt;/p&gt;&lt;p&gt;Co-author Yu Jo Chua disclosed relationships with Roche and sanofi-aventis.&lt;/p&gt;&lt;p&gt;Co-author Gina Brown disclosed a relationship with sanofi-aventis.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_304"
                     title="&apos;Virtual&apos; Colon Scans Effective in Seniors (CME/CE)"
                     score="0.005"
                     href="http://www.medpagetoday.com/HematologyOncology/ColonCancer/tb/18164?impressionId=1265796437424"
                     
      Patients 65 and older are as suitable as younger individuals for CT colonography, said researchers conducting a large retrospective study.&lt;br&gt;
&lt;br&gt;Advanced neoplasias were detected with CT colonography  --  often called &quot;virtual colonoscopy&quot;  --  in older patients at more than double the rate in the general screening population, reported David H. Kim, MD, of the University of Wisconsin in Madison, Wis., and colleagues in the February issue of &lt;em&gt;Radiology&lt;/em&gt;.&lt;br&gt;
&lt;br&gt;They found that 7.6% of older patients had advanced neoplasias, compared with 3.2% of all patients screened in the university&apos;s clinic (&lt;em&gt;P&lt;/em&gt;&amp;lt;0.001).&lt;/p&gt;
&lt;p&gt;On the basis of this and other findings in 577 individuals 65 and older versus the entire group of 3,120 patients undergoing the procedure, Kim and colleagues concluded that &quot;CT colonography performance is maintained in an older cohort.&quot;&lt;/p&gt;
&lt;p&gt;&quot;Overall, the observations from this clinical experience confirm that CT colonography may be a valuable screening modality in the older population,&quot; they wrote.&lt;/p&gt;
&lt;p&gt;On the other hand, the study did not address several objections raised by the Centers for Medicare and Medicaid Services (CMS) in its decision last year to deny Medicare coverage for the procedure. (See &lt;a href=&quot;http://www.medpagetoday.com/PublicHealthPolicy/Medicare/14186&quot; mce_href=&quot;http://www.medpagetoday.com/PublicHealthPolicy/Medicare/14186&quot; target=&quot;_blank&quot;&gt;Medicare Finalizes Denial of Virtual Colonoscopy Coverage&lt;/a&gt;)&lt;/p&gt;
&lt;p&gt;CMS had pointed to relatively low sensitivity of CT colonography compared with optical colonoscopy in prospective trials, especially for small lesions.&lt;/p&gt;
&lt;p&gt;The agency also determined that CT colonography increased the costs of positive findings, since abnormalities in the CT scans must be confirmed with optical colonoscopy. In addition, CMS said there was no evidence to support claims that the less invasive imaging procedure would be more acceptable to patients and therefore would raise screening rates.&lt;/p&gt;
&lt;p&gt;The data analyzed by Kim and colleagues did not allow for calculations of false-negative rates or predictive values of positive or negative findings. Nor did the researchers report cost information.&lt;/p&gt;
&lt;p&gt;Mean age of their older cohort was 69.2 (SD 3.8). The oldest was 79.&lt;/p&gt;
&lt;p&gt;The researchers reported that 15.3% of the older patients were referred for optical colonoscopy on the basis of the CT results, compared with 7.9% of the overall screening group.&lt;/p&gt;
&lt;p&gt;Less than 4% of positive findings were determined to be false with the optical procedure (3.6% for polyps 6 to 10 mm in diameter, 2.1% for larger lesions).&lt;/p&gt;
&lt;p&gt;Of the 59 advanced neoplasias identified in the older patients, all but three were at least 10 mm in size.&lt;/p&gt;
&lt;p&gt;The scans also suggested abnormalities outside the colon in 89 (15.4%) patients. Of these, 45 received a full workup, which revealed substantial and previously unsuspected diagnoses in 21 cases  -- 18 were vascular aneurysms. The other three included one lung tumor, a femoral hernia, and a malrotation.&lt;/p&gt;
&lt;p&gt;Kim and colleagues reported that no &quot;substantial complications&quot; such as perforations or major hemorrhage occurred in the older patients, either with the CT scan or follow-up colonoscopy.&lt;/p&gt;
&lt;p&gt;They also indicated that the ratio of large to small neoplasias was similar in the older patients compared with their CT screening group as a whole. Histologic and morphologic findings were similar as well.&lt;/p&gt;
&lt;p&gt;The researchers cited the observational nature of the study, in which negative findings were not corroborated with optical colonoscopy, and its restriction to a single center as its main limitations.&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;No external funding for the study was reported.&lt;/p&gt;&lt;p&gt;Kim and one co-author reported relationships with Viatronix and Medicsight and are co-founders of a company called VirtuoCTC, which produces educational materials on CT colonography.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
    <recommendedItem id="20100101_19_276"
                     title="ASCO GI: Antibody Slows Metastatic Colon Cancer"
                     score="0.004"
                     href="http://www.medpagetoday.com/MeetingCoverage/ASCOGI/tb/18134?impressionId=1265796437424"
                     
      ORLANDO  --  Patients with nonmutated colorectal tumors had significant improvement in progression-free survival (PFS) when the monoclonal antibody panitumumab (Vectibix) was added to conventional chemotherapy, data from two randomized clinical trials showed.&lt;br&gt;
&lt;br&gt;When used in first-line therapy for metastatic cancer, the antibody-chemotherapy combination was associated with a 20% improvement in the hazard ratio for progression compared with chemotherapy alone. In the second-line metastatic setting, the combination improved the hazard ratio by 27%.&lt;br&gt;
&lt;br&gt;Separate analyses of the trials showed that the addition of panitumumab to chemotherapy did not improve PFS in patients whose tumors had K-ras mutations.&lt;br&gt;
&lt;br&gt;Overall survival was similar between treatment arms in both trials, according to presentations here at the Gastrointestinal Cancers Symposium.&lt;p&gt;&lt;/p&gt;
&lt;p&gt;&quot;The results of these two studies are consistent in that they demonstrate a benefit from the addition of panitumumab among patients with wild-type K-ras tumors,&quot; Salvatore Siena, MD, of Ospedale Niguarda Ca&apos;Granda in Milan, Italy, said in an interview. &quot;The results also are consistent with what we know about the role of K-ras in colorectal cancer.&quot;&lt;/p&gt;
&lt;p&gt;&quot;The addition of panitumumab to the chemotherapy regimens used in the studies was well tolerated, as no unexpected toxicity was observed,&quot; he added.&lt;/p&gt;
&lt;p&gt;Panitumumab is a fully human monoclonal antibody against epidermal growth factor receptor (EGFR). The agent is approved for treatment of chemotherapy-refractory metastatic colorectal cancer.&lt;/p&gt;
&lt;p&gt;The two clinical trials initially were designed to evaluate panitumumab in all patients, irrespective of K-ras status. Following reports about the adverse effect of K-ras mutations on therapeutic outcomes in colorectal cancer, the trials&apos; protocols were amended to test the hypothesis that adding panitumumab to chemotherapy would improve PFS in patients with wild-type K-ras status.&lt;/p&gt;
&lt;p&gt;The trial of first-line metastatic therapy compared panitumumab plus 5-FU/leucovorin/oxaliplatin (Eloxatin) chemotherapy versus chemotherapy (FOLFOX) alone. The open-label, randomized trial involved 1,183 patients enrolled at centers in Canada, South America, Europe, South Africa, and Australia.&lt;/p&gt;
&lt;p&gt;The primary endpoint was PFS, and secondary endpoints included overall survival, overall response rate, time to response, duration of response, and safety. The protocol excluded patients with prior chemotherapy for metastatic colorectal cancer or prior EGFR inhibitor therapy.&lt;/p&gt;
&lt;p&gt;Tissue samples were collected for biomarker assessment, but EGFR and K-ras status assessment were not required at entry. Siena said K-ras status was ascertained in 93% of the patients and showed that 60% of both treatment arms had wild-type K-ras tumors.&lt;/p&gt;
&lt;p&gt;In the primary analysis involving patients with wild-type K-ras tumors, the addition of panitumumab to FOLFOX was associated with a PFS of 9.6 months compared with 8.0 months for patients treated with chemotherapy alone (HR 0.80, 95% CI 0.66 to 0.97, &lt;em&gt;P&lt;/em&gt;=0.02). Addition of the antibody was associated with a trend toward improved overall survival (23.9 months versus 19.7 months, &lt;em&gt;P&lt;/em&gt;=0.07) and overall response rate (55% versus 48%, &lt;em&gt;P&lt;/em&gt;=0.07).&lt;/p&gt;
&lt;p&gt;Patients with mutant-type K-ras tumors fared better with chemotherapy alone, which led to a median PFS of 8.8 months versus 7.3 months for chemotherapy plus panitumumab (&lt;em&gt;P&lt;/em&gt;=0.02).&lt;/p&gt;
&lt;p&gt;Similar results emerged from the study of second-line therapy for metastatic cancer, reported by Marc Peeters, MD, of University Hospital Ghent in Belgium.&lt;/p&gt;
&lt;p&gt;The trial involved 1,186 patients who had previously received chemotherapy for metastatic colorectal cancer enrolled at centers in the U.S., Europe, Asia, and Australia. As in the study of first-line therapy, about 60% of the patients had wild-type K-ras tumors.&lt;/p&gt;
&lt;p&gt;The trial compared FOLFIRI chemotherapy (5-FU/leucovorin/irinotecan [Camptosar]) alone versus FOLFIRI plus panitumumab.&lt;/p&gt;
&lt;p&gt;Among patients with wild-type K-ras tumors, the addition of panitumumab was associated with a median PFS of 5.9 months versus 3.9 months for chemotherapy alone (HR 0.73, 95% CI 0.59 to 0.90, &lt;em&gt;P&lt;/em&gt;=0.004).&lt;/p&gt;
&lt;p&gt;Median overall survival was 14.5 months with the monoclonal antibody and 12.5 months without, a difference that did not reach statistical significance. The overall response rate was significantly higher in the panitumumab arm (35% versus 10%, &lt;em&gt;P&lt;/em&gt;=0.001).&lt;/p&gt;
&lt;p&gt;As in the first-line study, patients with mutant K-ras tumors did not benefit from the addition of panitumumab, which was associated with a median PFS of 5.0 months versus 4.9 months with chemotherapy alone. Overall survival was 11.8 months with panitumumab and 11.1 months without it, a nonsignificant difference.&lt;/p&gt;
&lt;p&gt;The panitumumab regimen was generally well tolerated in both studies. The principal difference in adverse events was an excess of skin toxicity with panitumumab, a recognized side effect of the monoclonal antibody.&lt;/p&gt;
&lt;div style=&quot;float:left;border-style:solid;border-width:1px;border-color:#8dabbc;font-family:arial;font-size:12px;background-color:#DBE9F2;padding:5px;&quot;&gt;&lt;p&gt;Both studies were supported by Amgen.&lt;/p&gt;&lt;p&gt;One or more investigators in the studies disclosed relatinships with Amgen, Merck Serono, Roche, Baxter International, Merck &amp;amp; Co., Roche, AstraZeneca, Bristol-Myers Squibb, Eli Lilly, ImClone Slystems, sanofi-aventis, and Pfizer.&lt;/p&gt;&lt;/div&gt;&lt;div style=&quot;clear:both;&quot;&gt;&lt;/div&gt;
    </recommendedItem>
</recommendedContent>