Efficacy and safety of same-day preparation with sodium picosulfate plus magnesium citrate on the day of colonoscopy for bowel preparation: Multicenter, single-arm, open-label study.

BACKGROUND AND AIM: Sodium picosulfate plus magnesium citrate (SP + MC) is a well-tolerated bowel preparation agent. However, Japan currently approves only two methods of taking SP + MC: the day-before and split-dose preparation, without approval of same-day preparations. This study aimed to evaluate the efficacy and safety of same-day SP + MC preparations. METHODS: This was a multicenter, single-arm, nonrandomized, open-label study. We enrolled 145 Japanese patients between June and December 2023. The patients received two sachets of SP + MC dissolved in 300 ml of water and 1200 mL or more of clear liquid on the day of colonoscopy. Bowel cleansing efficacy, adverse events (AEs), and patient satisfaction were evaluated. RESULTS: Of the enrolled patients, 137 underwent colonoscopy according to our protocol. Bowel preparation was adequate in 133 patients (97.1%). The mean total Boston Bowel Preparation Score was 8.3 ± 1.2. Five patients experienced AEs (3.6%): two (1.5%), abdominal pain; one (0.73%), ischemic enteritis; one (0.73%), vomiting or nausea; and one (0.73%), headache. All AEs were treated conservatively. None of the patients exhibited abnormal blood test results or clinical symptoms after receiving SP + MC. Regarding patient satisfaction, all patients were able to take SP + MC as directed; 136 (99.2%) expressed a preference for this bowel preparation for future colonoscopies. CONCLUSION: The same-day SP + MC preparation showed high bowel-cleansing efficacy and satisfaction in Japanese patients without serious AEs.

Characteristics of Gastric Stasis due to Deformation after Endoscopic Submucosal Dissection in the Lower Part of the Stomach.

INTRODUCTION: Gastric stasis due to deformation occurs after endoscopic submucosal dissection in the lower part of the stomach. Endoscopic balloon dilation can improve gastric stasis due to stenosis; however, endoscopic balloon dilation cannot improve gastric stasis due to deformation. Furthermore, the characteristics of gastric stasis due to deformation are unknown. This study aimed to evaluate the characteristics of gastric stasis due to deformation after endoscopic submucosal dissection in the lower part of the stomach, focusing on the differences between stenosis and deformation. METHODS: We retrospectively reviewed 41 patients with gastric stasis after endoscopic submucosal dissection in the lower part of the stomach. We evaluated the characteristics of cases with gastric stasis due to deformation, such as the risk factors of deformation and the rate of deformation in each group with risk factors. RESULTS: Deformation was observed in 12% (5/41) of the patients with gastric stasis. All cases of deformation had a circumferential extent of the mucosal defect greater than 3/4. The number of cases with pyloric dissection was significantly lower in the deformation group than in the non-deformation group (0% vs. 72%; p = 0.004). The deformation group also had a significantly higher number of cases with angular dissection than the non-deformation group (100% vs. 17%; p < 0.001). Moreover, the deformation cases had a significantly larger specimen diameter (p < 0.001). Deformation was observed only in cases with angular and non-pyloric dissections. Deformation was not observed in cases with angular and pyloric dissections. CONCLUSIONS: All cases of gastric stasis due to deformation had a circumferential extent of the mucosal defect greater than 3/4. Deformation was also likely to occur in cases with a larger dissection that exceeded the angular region without pyloric dissection.

Clinicopathological Features and the Prevalence of Oxyntic Gland Neoplasm: A Single-center Retrospective Study.

Objective We explored the clinicopathological characteristics and disease frequency of oxyntic gland neoplasms (OGNs). Methods We retrospectively evaluated the data of patients pathologically diagnosed with OGN at an internal medicine clinic. Patients A total of 13,240 upper gastrointestinal endoscopies were performed on 7,488 patients between December 1, 2017, and March 31, 2021. Results We identified 27 patients with 30 histopathologically confirmed OGNs, yielding a disease frequency of 0.36% (27/7,488). Furthermore, multiple simultaneous lesions were found in 3 of 27 patients (11%). One (3.3%) of the 30 lesions was present in the antrum, whereas the remaining lesions occurred in the body of the stomach. Nine (33%) of the 27 patients had no history of Helicobacter pylori infection, whereas the remaining 18 (67%) were either currently or had been previously infected. Nevertheless, 27/30 lesions (90%) still occurred in non-atrophied regions. After endoscopic treatment, a histopathological examination of the resected specimens revealed submucosal infiltration in 8 (44%) of the 18 lesions; however, none of the lesions showed submucosal desmoplasia. For all patients with submucosal involvement, only observation was performed. There were no recurrent lesions found on follow-up. Conclusion The period prevalence of OGN was 0.36%, which is much higher than previously reported. The discovery of a small submucosal appearing lesion with a faded yellow or white color and dilated microvasculature, especially in a non-atrophic area of the stomach, should raise suspicion for an OGN, which can be endoscopically managed.

Risk-scoring system for predicting challenging cases of peroral endoscopic myotomy.

OBJECTIVES: Peroral endoscopic myotomy (POEM) is an effective treatment for esophageal motility disorders including achalasia and its variants. However, some surgeons have encountered challenging cases. This study aimed to develop a risk-scoring system to predict challenging cases of POEM. METHODS: Consecutive patients who underwent POEM between April 2015 and March 2020 at our hospital were included in this single-center retrospective study. Challenging cases of POEM were defined as patients with any of the following: (i) procedure time ≥90 min; (ii) mucosal perforation; (iii) pneumothorax; and (iv) major bleeding. A risk-scoring system for predicting challenging cases was developed based on multivariate logistic regression and internal validation was performed using the bootstrap method. Clinical usefulness was evaluated using a decision curve analysis. RESULTS: Of the 467 patients, 59 (12.6%) had challenging POEM. A risk-scoring system consisted of four variables: duration of symptoms ≥5 years (assigned score, 1 point), antithrombotics use (1 point), manometric diagnosis of achalasia variants (2 points), and dilation grade 3 (2 points). Our scoring system showed satisfactory discrimination (area under the receiver operating characteristic curve, 0.69; 95% confidence interval [CI] 0.61-0.77) and calibration (slope, 0.99; 95% CI 0.65-1.35). The decision curve analysis demonstrated its clinical usefulness. CONCLUSIONS: We established a risk-scoring system to predict challenging cases of POEM. This scoring system may aid the selection of patients who require treatment from experienced surgeons.

Predicting Inadequate Bowel Preparation When Using Sodium Picosulfate plus Magnesium Citrate for Colonoscopy: Development and Validation of a Prediction Score.

INTRODUCTION: Sodium picosulfate plus magnesium citrate is a bowel preparation agent with high patient acceptability. However, it is unclear which patients are more likely to have inadequate bowel preparation when using this agent. This study aimed to identify the risk factors for inadequate bowel preparation when using sodium picosulfate plus magnesium citrate for colonoscopy and to develop a scoring model to predict which patients will have inadequate bowel preparation. METHODS: A total of 350 Japanese patients were enrolled from June 2021 to April 2022. Data on patient background, details of colonoscopy, and satisfaction assessment questionnaire results were prospectively collected. The scoring model for inadequate bowel preparation was developed based on multiple logistic regression analyses, and its performance was internally validated using bootstrapping. RESULTS: Adequate bowel preparation was obtained in 295 patients (84.3%); 335 (95.7%) were able to ingest the drug without difficulty. The scoring model consisted of five independent risk factors and points of risk scores were assigned to each one as follows: American Society of Anesthesiologists physical status III (1 point), diabetes comorbidities (5 points), use of laxatives (4 points), no defecation once in a day (2 points), and drug use for mental disorder (6 points). The C-statistics of the scoring system for inadequate bowel preparation was 0.75. DISCUSSION: We identified five risk factors for inadequate bowel preparation when using sodium picosulfate plus magnesium citrate regimen and developed a scoring model for inadequate bowel preparation with satisfactory discrimination and calibration.

Feasibility and safety of endoscopic submucosal dissection for lesions in proximity to a colonic diverticulum.

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) for diverticulum-associated colorectal lesions is generally contraindicated because of the high risk of perforation. Several studies on patients with such lesions treated with ESD have been reported recently. However, the feasibility and safety of ESD for lesions in proximity to a colonic diverticulum (D-ESD) have not been fully clarified. The aim of this study was to evaluate the feasibility and safety of D-ESD. METHODS: D-ESD was defined as ESD for lesions within approximately 3 mm of a diverticulum. Twenty-six consecutive patients who underwent D-ESD were included. Two strategic approaches were used depending on whether submucosal dissection of the diverticulum-related part was required (strategy B) or not (strategy A). Treatment outcomes and adverse events associated with each strategy were analyzed. RESULTS: The en bloc resection rate was 96.2%. The rates of R0 and curative resection in strategies A and B were 80.8%, 73.1%, 84.6%, and 70.6%, respectively. Two cases of intraoperative perforation and one case of delayed perforation occurred. The delayed perforation case required emergency surgery, but the other cases were managed conservatively. CONCLUSION: D-ESD may be a feasible treatment option. However, it should be performed in a high-volume center by expert hands because it requires highly skilled endoscopic techniques.

Esophageal motility disorders missed during endoscopy.

BACKGROUND: Esophageal motility disorders are sometimes misdiagnosed on endoscopic examination. We aimed to identify the proportion of patients with esophageal motility disorders missed during endoscopy and their clinical characteristics. METHODS: Patients diagnosed with either disorder with esophagogastric junction outflow obstruction or major disorders of peristalsis using high-resolution manometry in our hospital from April 2015 to March 2021 were included in this study. Missed esophageal motility disorders were defined as patients with any endoscopic misdiagnosis such as normal esophagus or esophagitis within 1 year before the manometric diagnosis. We determined the proportion of missed esophageal motility disorders and identified independent predictors of missed esophageal motility disorders using multivariate analysis. RESULTS: A total of 41/273 esophageal motility disorders (15.0%; 95% confidence interval 11.3-19.7%) were missed during endoscopy within 1 year before manometric diagnosis. In the stepwise logistic regression analysis, the following variables were selected as independent variables for patients with missed esophageal motility disorders during endoscopy: non-dilated esophagus (odds ratio = 4.87, 95% confidence interval: 1.81-13.12, p = 0.002), the presence of epiphrenic diverticulum (odds ratio = 8.95, 95% confidence interval: 1.88-42.65, p = 0.006), the use of transnasal endoscopy (odds ratio = 4.71, 95% confidence interval: 1.59-13.92, p = 0.005), and the combined use of esophagram (odds ratio = 0.023, 95% confidence interval: 0.0025-0.20, p = 0.0008). CONCLUSIONS: Based on retrospective analysis, 15% of esophageal motility disorders were missed during endoscopy. Understanding the clinical characteristics of missed esophageal motility disorders could help improve endoscopic diagnoses.

Clinical Impact of Different Reconstruction Methods on Remnant Gastric Cancer at the Anastomotic Site after Distal Gastrectomy.

BACKGROUND/AIMS: The anastomotic site after distal gastrectomy is the area most affected by duodenogastric reflux. Different reconstruction methods may affect the lesion characteristics and treatment outcomes of remnant gastric cancers at the anastomotic site. We retrospectively investigated the clinicopathologic and endoscopic submucosal dissection outcomes of remnant gastric cancers at the anastomotic site. METHODS: We recruited 34 consecutive patients who underwent endoscopic submucosal dissection for remnant gastric cancer at the anastomotic site after distal gastrectomy. Clinicopathology and treatment outcomes were compared between the Billroth II and non-Billroth II groups. RESULTS: The tumor size in the Billroth II group was significantly larger than that in the non-Billroth II group (22 vs. 19 mm; p=0.048). More severe gastritis was detected endoscopically in the Billroth II group (2 vs. 1.33; p=0.0075). Moreover, operation time was longer (238 vs. 121 min; p=0.004) and the frequency of bleeding episodes was higher (7.5 vs. 3.1; p=0.014) in the Billroth II group. CONCLUSION: Compared to remnant gastric cancers in non-Billroth II patients, those in the Billroth II group had larger lesions with a background of severe remnant gastritis. Endoscopic submucosal dissection for remnant gastric cancers in Billroth II patients involved longer operative times and more frequent bleeding episodes than that in patients without Billroth II.

Timing of pyloric stenosis and effectiveness of endoscopic balloon dilation after pyloric endoscopic submucosal dissection.

BACKGROUND AND AIM: There have been studies on risk factors for stenosis after pyloric endoscopic submucosal dissection (ESD). However, the most appropriate strategies for the management of cases with these risk factors have not been established. This study aimed to investigate post-ESD management by evaluating the timing of stenosis and the effectiveness of endoscopic balloon dilation (EBD) after pyloric ESD. METHODS: We retrospectively reviewed cases of pyloric ESD. We first reassessed risk factors for stenosis in multivariate analysis and receiver operating characteristic curve and defined patients with the identified risk factors as the risk group. The primary outcome was the timing of stenosis in the risk group assessed by the Kaplan-Meier method. RESULTS: We reviewed 159 cases with pyloric ESD and observed pyloric stenosis in 25 cases. Cases with circumferential mucosal defect ≥ 76% were identified as the risk group. The stenosis-free probability in the risk group was 97% (95% confidence interval [CI]: 79-100%), 94% (95% CI: 76-98%), and 85% (95% CI: 66-93%) on days 7, 14, and 21, respectively. It decreased every week thereafter and did not significantly change after day 56. Twenty-three stenosis cases, except for conservative improvement, including six whole circumferential pyloric ESD cases, were improved by EBD without complications. CONCLUSIONS: Post-ESD stenosis often developed from the third to the eighth week. In all pyloric ESD cases, including whole circumferential pyloric ESD cases, pyloric stenosis was improved following EBD without complications.

Peroral endoscopic myotomy for advanced achalasia with megaesophagus.

BACKGROUND: The outcomes of peroral endoscopic myotomy for advanced achalasia are not well known. This study aimed to evaluate the outcomes of peroral endoscopic myotomy for achalasia with megaesophagus, which is one of the characteristics of advanced achalasia. METHODS: In total, 234 patients with achalasia who underwent peroral endoscopic myotomy in our hospital from April 2015 to March 2019 were included in this retrospective observational study. Megaesophagus was defined as a maximum esophageal diameter of 6 cm or more. Outcomes, including clinical success (Eckardt score ≤ 3 without retreatment) at the 1-year follow-up, technical success, and perioperative complications, were investigated and compared between patients with and without megaesophagus. RESULTS: Eleven patients (4.7%) were diagnosed with megaesophagus. The clinical success rate achieved was 63.6% in patients with megaesophagus, with a significant decrease in the Eckardt score (6 vs. 2, p = 0.003) and integrated relaxation pressure (28 mmHg vs. 9 mmHg, p = 0.028). The technical success rate was 100%. However, patients with megaesophagus had a significantly lower clinical success rate than those without megaesophagus (63.6% vs. 96.0%, p = 0.002). Furthermore, patients with megaesophagus had significantly higher rates of major adverse events than those without megaesophagus (18.2% vs. 2.7%, p = 0.048). CONCLUSIONS: Peroral endoscopic myotomy improved achalasia-related symptoms, and this was technically feasible in patients with megaesophagus. However, the clinical success rate was somewhat low, and the rate of major adverse events was high. Therefore, peroral endoscopic myotomy should be carefully performed for advanced achalasia with megaesophagus.

Factors associated with inaccurate size estimation of colorectal polyps: A multicenter cross-sectional study.

BACKGROUND AND AIM: Accurate polyp size estimation is essential in deciding the therapeutic strategy of colorectal polyps and endoscopic surveillance intervals. However, many endoscopists frequently make incorrect size estimations without being aware of their errors. This cross-sectional study aimed to clarify the characteristics of endoscopists associated with inaccurate estimation. METHODS: We previously conducted a web trial involving 261 endoscopists in 51 institutions in Japan to assess their ability to estimate polyp size. Participants answered questions about polyp size using visual estimates in a test involving images of 30 polyps. Here, we investigated the relationships between inaccurate size estimation and the backgrounds of participants. The rates of overestimation and underestimation of polyp size were also compared to clarify any trends in the answers of participants with low accuracy (< 50%). RESULTS: Multivariable logistic regression analysis revealed that the number of colonoscopic procedures in the past year was the only factor associated with a low accuracy of polyp size estimation (odds ratio 0.750, 95% confidence interval 0.609-0.925; P = 0.007). Endoscopists with low accuracy had a greater tendency to overestimate polyp size (42.3% overestimation and 21.2% underestimation, P < 0.001) compared with other endoscopists (16.6% overestimation and 17.9% underestimation, P = 0.951). CONCLUSIONS: Endoscopists with limited experience of colonoscopy in the past year were more likely to make frequent errors in size estimation. Furthermore, endoscopists making inaccurate size estimations had a propensity to overestimate polyp size.

Development of a preoperative risk-scoring system for predicting poor responders to peroral endoscopic myotomy.

BACKGROUND AND AIMS: Peroral endoscopic myotomy (POEM) is an effective treatment for esophageal motility disorder. However, some people are poor responders who will probably need retreatments, such as endoscopic pneumatic dilation or re-POEM, and a scoring system for the prediction of poor responders preoperatively has not yet been established. We aimed to develop and validate a preoperative scoring system for predicting poor responders. METHODS: Overall, 244 patients who underwent POEM for esophageal motility disorders in our hospital from April 2015 to March 2019 were retrospectively included in this study. Poor responders were defined as patients with any of following: (1) Eckardt score ≥3 at 1-year follow-up, (2) endoscopic findings of food retention at 1-year follow-up, and (3) retreatments within 1 year after POEM. A risk-scoring system for poor responders was developed based on multiple logistic regression analysis, and its performance was internally validated using bootstrapping. RESULTS: Forty patients were diagnosed as poor responders at the 1-year follow-up. In the multivariate study, points for risk scores were assigned for 4 independent risk factors as follows: pretreatment Eckardt score (1-point increments), previous treatments (4 points), sigmoid-type esophagus (4 points), and esophageal dilation grade ≥II (4 points). The scoring system could predict an estimated risk for poor responders and provided satisfactory discrimination (area under the receiver operating characteristic curve, 0.78; 95% confidence interval, 0.68-0.88) and calibration (slope = 0.93; 95% confidence interval, 0.62-1.31). CONCLUSIONS: A validated risk-scoring system for predicting poor responders preoperatively was established; this system could be useful for selecting treatment strategies and postoperative surveillance.

Comparison of the safety and efficacy of peroral endoscopic myotomy between octogenarians and non-octogenarians.

OBJECTIVES: This study compared the safety and efficacy of peroral endoscopic myotomy for esophageal motility disorders between octogenarians and non-octogenarians. METHODS: This retrospective observational study recruited 321 patients (28 octogenarians and 293 non-octogenarians) who underwent peroral endoscopic myotomy from two institutions. Clinical success (postoperative Eckardt score ≤ 3), technical success (completion of gastric and esophageal myotomy), and perioperative adverse events were compared between octogenarians and non-octogenarians. Perioperative adverse events were classified into major and minor adverse events based on the International Peroral Endoscopic Myotomy Survey criteria and were subdivided into technical and non-technical adverse events according to the presence of a direct causal relationship with the procedure. RESULTS: There were no significant differences in the rates of clinical success 1 year after treatment (100% vs. 97.3%, P = 0.64) and technical success (100% vs. 99.7%, P = 0.91) between octogenarians and non-octogenarians. Octogenarians had a higher incidence of perioperative adverse events (28.6% vs. 10.2%, P = 0.00097), particularly major adverse events (25.0% vs. 3.0%, P < 0.0001). There were no significant differences in the incidence of minor adverse events (7.1% vs. 7.9%, P = 0.67). Although there was no difference in the incidence of technical adverse events (10.7% vs. 9.2%, P = 0.74), octogenarians had a significantly higher incidence of non-technical adverse events (17.9% vs. 1.0%, P = 0.0002). CONCLUSIONS: There were no significant differences in short-term clinical success and technical success between octogenarians and non-octogenarians. However, octogenarians showed a significantly higher incidence of perioperative adverse events, particularly in major adverse events and non-technical adverse events. Peroral endoscopic myotomy for octogenarians should be carefully applied.

Feasibility and Safety of Endoscopic Submucosal Dissection for Recurrent Rectal Lesions that after Transanal Endoscopic Microsurgery: A Case Series.

OBJECTIVES: Recently, several studies have demonstrated the usefulness of endoscopic submucosal dissection (ESD) for residual or locally recurrent colorectal lesions after endoscopic treatment. However, the feasibility of ESD for recurrent rectal lesions after transanal endoscopic microsurgery (TEM) has not been fully investigated. In this study, we evaluated the feasibility and safety of ESD for recurrent rectal lesions after TEM. METHODS: The treatment outcomes of 10 lesions in 9 patients, who underwent ESD between January 2006 and March 2018 for recurrent rectal lesions after transanal endoscopic microsurgery, were evaluated. RESULTS: All lesions were successfully resected en bloc, and the R0 resection rate was 90%. The median size of the resected specimens and lesions (range) was 44 mm (21-70) and 27.5 mm (5-60), respectively. The pathological diagnoses included 4 adenomas and 6 cancerous lesions. The cancerous lesions included 5 cases of mucosal cancer and 1 case of superficial submucosal invasive cancer (depth of submucosal invasion <1,000 µm from the muscularis mucosae). No adverse events occurred. There was no recurrence during the follow-up period. CONCLUSIONS: ESD for recurrent rectal lesions after TEM by expert's hands appears to be safe and feasible.

Early gastric cancer involving a pure enteroblastic differentiation component that was curatively resected via endoscopic submucosal dissection.

Gastric adenocarcinoma with enteroblastic differentiation (GAED) is a very rare variant of alpha-fetoprotein-producing gastric cancer (AFPGC). GAED is histologically characterized by cuboidal or columnar cells, which resemble those found in the primitive gut and have clear cytoplasm. In previously reported cases, GAED exhibit more aggressive behavior, as well as AFPGC, than conventional gastric cancer, such as marked lymphovascular invasion, lymph node metastasis, and liver metastasis. And also GAED was usually located in a deep mucosal layer and was covered by a conventional adenocarcinoma (CA) component. Based on these findings, GAED is considered to develop from CA during the process of tumor invasion and proliferation. We present a very rare case of early-stage GAED achieved curatively resected via endoscopic submucosal dissection, in which the lesion was composed of a pure enteroblastic differentiation component without a CA component.

Continuous Anticoagulation and Cold Snare Polypectomy Versus Heparin Bridging and Hot Snare Polypectomy in Patients on Anticoagulants With Subcentimeter Polyps: A Randomized Controlled Trial.

Background: Management of anticoagulants for patients undergoing polypectomy is still controversial. Cold snare polypectomy (CSP) is reported to cause less bleeding than hot snare polypectomy (HSP). Objective: To compare outcomes between continuous administration of anticoagulants (CA) with CSP (CA+CSP) and periprocedural heparin bridging (HB) with HSP (HB+HSP) for subcentimeter colorectal polyps. Design: Multicenter, parallel, noninferiority randomized controlled trial. (University Hospital Medical Information Network Clinical Trials Registry: UMIN000019355). Setting: 30 Japanese institutions. Patients: Patients receiving anticoagulant therapy (warfarin or direct oral anticoagulants) who had at least 1 nonpedunculated subcentimeter colorectal polyp. Intervention: Patients were randomly assigned to undergo HB+HSP or CA+CSP and followed up 28 days after polypectomy. Measurements: The primary end point was incidence of polypectomy-related major bleeding (based on the incidence of poorly controlled intraprocedural bleeding or postpolypectomy bleeding requiring endoscopic hemostasis). The prespecified inferiority margin was -5% (CA+CSP vs. HB+HSP). Results: A total of 184 patients were enrolled: 90 in the HB+HSP group, 92 in the CA+CSP group, and 2 who declined to participate after enrollment. The incidence of polypectomy-related major bleeding in the HB+HSP and CA+CSP groups was 12.0% (95% CI, 5.0% to 19.1%) and 4.7% (CI, 0.2% to 9.2%), respectively. The intergroup difference for the primary end point was +7.3% (CI, -1.0% to 15.7%), with a 0.4% lower limit of 2-sided 90% CI, demonstrating the noninferiority of CA+CSP. The mean procedure time for each polyp and the hospitalization period were longer in the HB+HSP than in the CA+CSP group. Limitation: An open-label trial assessing 2 factors (anticoagulation approach and polypectomy procedure type) simultaneously. Conclusion: Patients having CA+CSP for subcentimeter colorectal polyps who were receiving oral anticoagulants did not have an increased incidence of polypectomy-related major bleeding, and procedure time and hospitalization were shorter than in those having HB+HSP. Primary Funding Source: Japanese Gastroenterological Association.

Comparison of Panitumumab Plus Irinotecan and Cetuximab Plus Irinotecan for KRAS Wild-type Metastatic Colorectal Cancer.

BACKGROUND/AIM: Panitumumab and cetuximab are known to be effective treatments for KRAS wild-type metastatic colorectal cancer (mCRC). However, it remains unclear which of these two biologic agents confers the greatest benefit when combined with irinotecan in patients with KRAS wild-type mCRC previously treated with fluoropyrimidine, oxaliplatin and irinotecan. PATIENTS AND METHODS: Data, from 139 patients who received panitumumab or cetuximab, in combination with irinotecan, for KRAS wild-type mCRC previously treated with fluoropyrimidine, oxaliplatin and irinotecan were analyzed. The efficacy and safety of panitumumab plus irinotecan was compared to that of cetuximab plus irinotecan. RESULTS: Baseline characteristics of the panitumumab plus irinotecan (n=42) and cetuximab plus irinotecan (n=97) groups were similar. Among patients with measurable lesions, the response rate was 34% in the panitumumab plus irinotecan group and 20% in the cetuximab plus irinotecan group. Median progression-free survival (PFS) was 4.3 and 5.7 months in the panitumumab and cetuximab groups, respectively. Median overall survival was 13.6 months with panitumumab and 11.2 months with cetuximab. CONCLUSION: Panitumumab plus irinotecan was well-tolerated and displayed a similar level of efficacy to that of cetuximab plus irinotecan.