Effect of M1a and M1b category in metastatic colorectal cancer

BACKGROUND

In 2009, the American Joint Committee on Cancer version 7 staging system introduced the M1 subclassifications M1a (single metastatic site) and M1b (peritoneal or multiple metastatic sites). The study objectives were to evaluate the prognostic effect of site of metastasis and M1a/b category among patients with newly diagnosed colorectal cancer and synchronous metastasis.

PATIENTS AND METHODS

Patients with newly diagnosed pathologic or clinical category M1 colorectal cancer referred to the British Columbia Cancer Agency between 1999 and 2007 were included. Demographic, tumor, treatment, and outcome data were prospectively collected, and prognostic factors were identified. Univariate Cox models were used to assess the prognostic impact of individual sites of metastasis and to determine the effect of M1a/b category on overall survival (OS).

RESULTS

Among 2,049 eligible patients, 70% had M1a and 30% M1b category disease. The most common sites of common single sites of metastasis included liver (56%), lung (5.3%), and peritoneum (3.6%). Metastasis to a single organ or site, including peritoneum, was associated with improved OS compared with multiple sites of metastasis. In multivariate analysis, M1b category conferred inferior survival and hazard ratio (HR) 1.38 (95% confidence interval [CI]: 1.22, 1.55), along with age >70 and Eastern Cooperative Oncology Group performance status of 3-4. Resection of primary tumor was associated with improved survival, HR 0.46 (95% CI: 0.41, 0.52). Results were similar in subgroup analysis of patients undergoing resection of their primary tumor when histology, tumor, and node category were included.

CONCLUSION

The results lend support to the introduction of M1a/b colorectal cancer categories. Consideration may be given to classifying patients with solitary peritoneal metastasis only as M1a rather than M1b category. Further refinement of category M1a to reflect resectability of metastasis at initial diagnosis may improve prognostication.

Pathologic and molecular features correlate with long-term outcome after adjuvant therapy of resected primary GI stromal tumor: the ACOSOG Z9001 trial

PURPOSE

The ACOSOG (American College of Surgeons Oncology Group) Z9001 (Alliance) study, a randomized, placebo-controlled trial, demonstrated that 1 year of adjuvant imatinib prolonged recurrence-free survival (RFS) after resection of primary GI stromal tumor (GIST). We sought to determine the pathologic and molecular factors associated with patient outcome.

PATIENTS AND METHODS

There were 328 patients assigned to the placebo arm and 317 to the imatinib arm. Median patient follow-up was 74 months. There were 645 tumor specimens available for mitotic rate or mutation analysis.

RESULTS

RFS remained superior in the imatinib arm (hazard ratio, 0.6; 95% CI, 0.43 to 0.75; Cox model-adjusted P < .001). On multivariable analysis of patients in the placebo arm, large tumor size, small bowel location, and high mitotic rate were associated with lower RFS, whereas tumor genotype was not significantly associated with RFS. Multivariable analysis of patients in the imatinib arm yielded similar findings. When comparing the two arms, imatinib therapy was associated with higher RFS in patients with a KIT exon 11 deletion of any type, but not a KIT exon 11 insertion or point mutation, KIT exon 9 mutation, PDGFRA mutation, or wild-type tumor, although some of these patient groups were small. Adjuvant imatinib did not seem to alter overall survival.

CONCLUSION

Our findings show that tumor size, location, and mitotic rate, but not tumor genotype, are associated with the natural history of GIST. Patients with KIT exon 11 deletions assigned to 1 year of adjuvant imatinib had a longer RFS.

Panitumumab monotherapy compared with cetuximab and irinotecan combination therapy in patients with previously treated KRAS wild-type metastatic colorectal cancer

BACKGROUND

The survival benefit for single-agent anti-epidermal growth factor receptor (egfr) therapy compared with combination therapy with irinotecan in KRAS wildtype (wt) metastatic colorectal cancer (mcrc) patients in the third-line treatment setting is not known. The objective of the present study was to describe the characteristics of, and to compare survival outcomes in, two cohorts of patients treated with either singleagent panitumumab or combination therapy with cetuximab and irinotecan.

METHODS

The study enrolled patients with KRAS wt mcrc previously treated with both irinotecan and oxaliplatin who had received either panitumumab or combination cetuximab-irinotecan before April 1, 2011, at the BC Cancer Agency (bcca). Patients were excluded if they had received anti-egfr agents in earlier lines of therapy. Data were prospectively collected, except for performance status (ps), which was determined by chart review. Information about systemic therapy was extracted from the bcca Pharmacy Database.

RESULTS

Of 178 eligible patients, 141 received panitumumab, and 37 received cetuximab-irinotecan. Compared with patients treated with cetuximab-irinotecan, panitumumab-treated patients were significantly older and more likely to have an Eastern Cooperative Oncology Group (ecog) ps of 2 or 3 (27.7% vs. 2.7%, p = 0.001). Other baseline prognostic variables and prior and subsequent therapies were similar. Median overall survival was 7.7 months for the panitumumab group and 8.3 months for the cetuximab-irinotecan group. Multivariate analysis demonstrated that survival outcomes were similar regardless of the therapy selected (hazard ratio: 1.28; p = 0.34). An ecog ps of 2 or 3 compared with 0 or 1 was the only significant prognostic factor in this treatment setting (hazard ratio: 3.37; p < 0.01).

CONCLUSIONS

Single-agent panitumumab and cetuximab-irinotecan are both reasonable third-line treatment options, with similar outcomes, for patients with chemoresistant mcrc.

Higher capecitabine AUC in elderly patients with advanced colorectal cancer (SWOGS0030)

Background:

The aging process is accompanied by physiological changes including reduced glomerular filtration and hepatic function, as well as changes in gastric secretions. To investigate what effect would aging have on the disposition of capecitabine and its metabolites, the pharmacokinetics between patients ⩾70 years and <60 years were compared in SWOG0030.

Methods:

Twenty-nine unresectable colorectal cancer patients were stratified to either ⩾70 or <60 years of age, where the disposition of capecitabine and its metabolites were compared.

Results:

Notable increase in capecitabine area under the curve (AUC) was accompanied by reduction in capecitabine clearance in ⩾70 years patients (P<0.05). No difference in 5'-deoxy-5-fluorocytidine, 5'-deoxy-5-fluorouridine (DFUR), and 5-fluorouracil (5FU) AUCs between the two age groups, suggesting that carboxylesterase and cytidine deaminase (CDA) activity was similar between the two age groups. These results suggest that metabolic enzymes involved in converting capecitabine metabolites are not altered by age. An elevation in capecitabine Cmax and reduction in clearance was seen in females, where capecitabine AUC was 40.3% higher in women. Elevation of DFUR Cmax (45%) and AUC (46%) (P<0.05) was also noted, suggesting that CDA activity may be higher in females.

Conclusion:

Increases in capecitabine Cmax and AUC was observed in patients ⩾70 years when compared with younger patients who were >60 years.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

Assessment of HER2 gene amplification in adenocarcinomas of the stomach or gastroesophageal junction in the INT-0116/SWOG9008 clinical trial

BACKGROUND

Trastuzumab has been approved for patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic gastric carcinoma; however, relatively little is known about the role of HER2 in the natural history of this disease.

PATIENTS AND METHODS

Patients enrolled in the INT-0116/SWOG9008 phase III gastric cancer clinical trial with available tissue specimens were retrospectively evaluated for HER2 gene amplification by FISH and overexpression by immunohistochemistry (IHC). The original trial was designed to evaluate the benefit of postoperative chemoradiation compared with surgery alone.

RESULTS

HER2 gene amplification rate by FISH was 10.9% among 258 patients evaluated. HER2 overexpression rate by IHC was 12.2% among 148 patients evaluated, with 90% agreement between FISH and IHC. There was a significant interaction between HER2 amplification and treatment with respect to both disease-free survival (DFS) (P = 0.020) and overall survival (OS) (P = 0.034). Among patients with HER2-non-amplified cancers, treated patients had a median OS of 44 months compared with 24 months in the surgery-only arm (P = 0.003). Among patients with HER2-amplified cancers, there was no significant difference in survival based on treatment arm. HER2 status was not a prognostic marker among patients who received no postoperative chemoradiation.

CONCLUSION

Patients lacking HER2 amplification benefited from treatment as indicated by both DFS and OS.

CLINICAL TRIAL

INT-0116/SWOG9008 phase III.

Microscopically positive margins for primary gastrointestinal stromal tumors: analysis of risk factors and tumor recurrence

BACKGROUND

Little is known about the outcomes of patients with microscopically positive (R1) resections for primary gastrointestinal stromal tumors (GIST) because existing retrospective series contain small numbers of patients. The objective of this study was to analyze factors associated with R1 resection and assess the risk of recurrence with and without imatinib.

STUDY DESIGN

We reviewed operative and pathology reports for 819 patients undergoing resection of primary GIST from the North American branch of the American College of Surgeons Oncology Group (ACOSOG) Z9000 and Z9001 clinical trials at 230 institutions testing adjuvant imatinib after resection of primary GIST. Patient, tumor, operative characteristics, factors associated with R1 resections, and disease status were analyzed.

RESULTS

Seventy-two (8.8%) patients had an R1 resection and were followed for a median of 49 months. Factors associated with R1 resection included tumor size (≥ 10 cm), location (rectum), and tumor rupture. The risk of disease recurrence in R1 patients was driven largely by the presence of tumor rupture. There was no significant difference in recurrence-free survival for patients undergoing an R1 vs R0 resection of GIST with (hazard ratio [HR] 1.095, 95% CI 0.66, 1.82, p = 0.73) or without (HR 1.51, 95% CI 0.76, 2.99, p = 0.24) adjuvant imatinib.

CONCLUSIONS

Approximately 9% of 819 GIST patients had an R1 resection. Significant factors associated with R1 resection include tumor size ≥ 10 cm, location, and rupture. The difference in recurrence-free survival with or without imatinib therapy in those undergoing an R1 vs R0 resection was not statistically significant at a median follow-up of 4 years.

SWOG 0514: a phase II study of sorafenib in patients with unresectable or metastatic gallbladder carcinoma and cholangiocarcinoma

OBJECTIVES

Gallbladder and cholangiocarcinomas represent a heterogeneous group of malignant diseases that commonly present at an advanced stage and have limited therapeutic options. Based on the role of the Ras-Raf-Mek-Erk pathway and the VEGF axis in biliary carcinomas, we conducted a phase II study of sorafenib in patients with advanced biliary cancers.

METHODS

Eligible patients had no prior therapy for metastatic or unresectable disease. Sorafenib was administered at 400 mg po twice daily continuously.

RESULTS

The study was terminated after the first stage of accrual due to failure to meet the primary objective. A confirmed response rate of 0% (0%-11%) was observed. Thirty-nine percent of patients demonstrated stable disease (including 2 with unconfirmed PR). PFS was 3 months (95% CI: 2-4 months) and OS 9 months (95% CI: 4-12 months). The most common grade 3 and 4 toxicities included hand-foot skin reaction (13%), bilirubin elevation (13%), venous thromboembolism (10%), AST/ALT elevation (10%) and elevated alkaline phosphatase (10%).

CONCLUSION

While treatment with sorafenib did not result in objective responses, patients with biliary cancers receiving this drug had some therapeutic benefit. Additional studies with sorafenib in combination with chemotherapy or other targeted agents may be warranted.

Updated analysis of SWOG-directed intergroup study 0116: a phase III trial of adjuvant radiochemotherapy versus observation after curative gastric cancer resection

PURPOSE

Surgical resection of gastric cancer has produced suboptimal survival despite multiple randomized trials that used postoperative chemotherapy or more aggressive surgical procedures. We performed a randomized phase III trial of postoperative radiochemotherapy in those at moderate risk of locoregional failure (LRF) following surgery. We originally reported results with 4-year median follow-up. This update, with a more than 10-year median follow-up, presents data on failure patterns and second malignancies and explores selected subset analyses.

PATIENTS AND METHODS

In all, 559 patients with primaries ≥ T3 and/or node-positive gastric cancer were randomly assigned to observation versus radiochemotherapy after R0 resection. Fluorouracil and leucovorin were administered before, during, and after radiotherapy. Radiotherapy was given to all LRF sites to a dose of 45 Gy.

RESULTS

Overall survival (OS) and relapse-free survival (RFS) data demonstrate continued strong benefit from postoperative radiochemotherapy. The hazard ratio (HR) for OS is 1.32 (95% CI, 1.10 to 1.60; P = .0046). The HR for RFS is 1.51 (95% CI, 1.25 to 1.83; P < .001). Adjuvant radiochemotherapy produced substantial reduction in both overall relapse and locoregional relapse. Second malignancies were observed in 21 patients with radiotherapy versus eight with observation (P = .21). Subset analyses show robust treatment benefit in most subsets, with the exception of patients with diffuse histology who exhibited minimal nonsignificant treatment effect.

CONCLUSION

Intergroup 0116 (INT-0116) demonstrates strong persistent benefit from adjuvant radiochemotherapy. Toxicities, including second malignancies, appear acceptable, given the magnitude of RFS and OS improvement. LRF reduction may account for the majority of overall relapse reduction. Adjuvant radiochemotherapy remains a rational standard therapy for curatively resected gastric cancer with primaries T3 or greater and/or positive nodes.

Phase II trial of neoadjuvant/adjuvant imatinib mesylate for advanced primary and metastatic/recurrent operable gastrointestinal stromal tumors: long-term follow-up results of Radiation Therapy Oncology Group 0132

BACKGROUND

Imatinib inhibits the KIT and PDGFR tyrosine kinases, resulting in its notable antitumor activity in gastrointestinal stromal tumor (GIST). We previously reported the early results of a multi-institutional prospective trial (RTOG 0132) using neoadjuvant/adjuvant imatinib either in primary resectable GIST or as a planned preoperative cytoreduction agent for metastatic/recurrent GIST. METHODS.: Patients with primary GIST (≥5 cm, group A) or resectable metastatic/recurrent GIST (≥2 cm, group B) received neoadjuvant imatinib (600 mg/day) for approximately 2 months and maintenance postoperative imatinib for 2 years. We have now updated the clinical outcomes including progression-free survival, disease-specific survival, and overall survival at a median follow-up of 5.1 years, and we correlate these end points with duration of imatinib therapy.

RESULTS

Sixty-three patients were originally entered (53 analyzable: 31 in group A and 22 in group B). Estimated 5-year progression-free survival and overall survival were 57% in group A, 30% in group B; and 77% in group A, 68% in group B, respectively. Median time to progression has not been reached for group A and was 4.4 years for group B. In group A, in 7 of 11 patients, disease progressed >2 years from registration; 6 of 7 patients with progression had stopped imatinib before progression. In group B, disease progressed in 10 of 13 patients>2 years from registration; 6 of 10 patients with progressing disease had stopped imatinib before progression. There was no significant increase in toxicity compared with our previous short-term analysis.

CONCLUSIONS

This long-term analysis suggests a high percentage of patients experienced disease progression after discontinuation of 2-year maintenance imatinib therapy after surgery. Consideration should be given to studying longer treatment durations in intermediate- to high-risk GIST patients.

A phase II trial of gemcitabine and capecitabine in patients with unresectable or metastatic gallbladder cancer or cholangiocarcinoma: Southwest Oncology Group study S0202

PURPOSE

Patients with gallbladder cancer or cholangiocarcinoma were treated with the combination of gemcitabine 1,000 mg/m(2) IV over 100 min on days 1 and 8 and capecitabine 650 mg/m(2) BID PO on days 1-14, administered every 21 days.

METHODS

The primary objective of this study was to assess the response rate (confirmed complete and partial responses) of gemcitabine and capecitabine used in advanced/metastatic biliary neoplasms. Secondary objectives included overall survival and toxicities.

RESULTS

The study accrued 57 patients from September 2003 to April 2005. Three patients were ineligible, and two others received no treatment. Characteristics of analyzable patients: 35 (67%) cholangiocarcinoma, 17 (33%) gallbladder cancer; PS 0 (18 pts), 1 (26 pts), 2 (8 pts); 26 (50%) men; median age 58.8 years (29.5-85.6). Among 51 patients evaluated for toxicity, 6 experienced grade 4 toxicities. Among 52 patients, there were 7 confirmed partial responses for a confirmed response probability of 13% (95% CI: 6-26%). Six patients had an unconfirmed partial response for an overall response probability of 25% (95% CI: 14-39%). Twelve patients (23%) demonstrated stable disease. The 6-month overall survival was 55% (95% CI: 41-69%), and median survival was 7 months (95% CI: 5-8 months).

CONCLUSIONS

The combination of gemcitabine and capecitabine is a well-tolerated regimen with activity in patients with advanced gallbladder cancer and cholangiocarcinoma.

Southwest Oncology Group study S0413: a phase II trial of lapatinib (GW572016) as first-line therapy in patients with advanced or metastatic gastric cancer

BACKGROUND

Lapatinib (GW572016) is a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/ErbB2), which are reported as overexpressed in 15%-45% of gastric cancers, making them potential targets.

PATIENTS AND METHODS

The primary objective of this study was to assess response rate. Secondary objectives included overall survival (OS), toxicity, and the relationship of EGFR, ErbB2, and markers of angiogenesis with clinical outcome. Lapatinib was administered to chemonaive metastatic gastric cancer patients at a dose of 1500 mg orally daily for 28 days.

RESULTS

The study enrolled 47 patients from February 2005 until May 2006. Four patients (9%) had a confirmed partial response (PR), 1 (2%) had an unconfirmed PR, and 10 (23%) had stable disease. Median (95% confidence interval) time to treatment failure was 1.9 (1.6-3.1) months and OS was 4.8 (3.2-7.4) months. Significant adverse events: one grade 4 cardiac ischemia/infarction, one grade 4 fatigue, and one grade 4 emesis. One treatment-related death was due to central nervous system ischemia. An exploratory analysis of markers revealed gene expression of HER2, interleukin (IL)-8 and genomic polymorphisms IL-8, and vascular endothelial growth factor correlated with OS.

CONCLUSIONS

Lapatinib is well tolerated, with modest single-agent activity in advanced/metastatic gastric cancer patients. Potential molecular correlatives were identified which warrant further validation.

Colorectal Chemoprevention Pilot Study (SWOG-9041), randomized and placebo controlled: the importance of multiple luminal lesions

BACKGROUND

Colorectal cancer is common worldwide and chemoprevention has the potential of reducing the number of individuals who may suffer and perish from this disease.

METHODS

A randomized placebo controlled pilot study in colorectal cancer patients was performed using calcium carbonate as the test agent in a multi-institutional oncology study group.

RESULTS

Two hundred twenty volunteers were randomized in the study. The primary goals of compliance, accrual, and toxicity monitoring are presented. Presence of multiple adenomas at study entry and subsequent development of metachronous adenomas were recorded and found to be associated with synchronous adenomas. The secondary endpoint of recurrent adenomas indicated lower rates of new adenoma in the volunteers randomized to the calcium group.

CONCLUSION

This pilot study indicates the feasibility of enrolling survivors of colorectal cancer as study volunteers in a colorectal neoplasm chemoprevention clinical trial and oral calcium continues to be a potentially effective drug in reducing colorectal adenomas.

S0356: a phase II clinical and prospective molecular trial with oxaliplatin, fluorouracil, and external-beam radiation therapy before surgery for patients with esophageal adenocarcinoma

PURPOSE

Pathologic complete response (pCR) after neoadjuvant therapy for locally advanced esophageal adenocarcinoma is associated with improved survival. The Southwest Oncology Group designed a trimodality, phase II, single-arm trial with objectives of achieving a pCR rate of 40% with prospective exploratory analyses of intratumoral molecular markers postulated to affect response and survival.

PATIENTS AND METHODS

Patients with clinically staged II or III esophageal adenocarcinoma received oxaliplatin 85 mg/m(2) on days 1, 15, and 29; protracted-infusion fluorouracil (PI-FU) 180 mg/m(2)/d on days 8 through 43; and external-beam radiation therapy (EBRT) 5 days a week at 1.8 Gy/d for 25 fractions; surgery was performed 28 to 42 days after neoadjuvant therapy. Chemotherapy was planned after surgery. Tumors were analyzed for mRNA expression and polymorphisms in genes involved in drug metabolism and DNA repair.

RESULTS

Ninety-three patients were evaluable. Two deaths (2.2%) were attributable to preoperative therapy, and two deaths (2.2%) were attributable to surgery. Grade 3 and 4 toxicities were recorded for 47.3% and 19.4% of patients, respectively. Seventy-nine patients (84.9%) underwent surgery; 67.7% of patients had R0 resections. Twenty-six patients (28.0%) had confirmed pCR (95% CI, 19.1% to 38.2%). At a median follow-up of 39.2 months, estimates of median and 3-year overall survival (OS) were 28.3 months and 45.1%, respectively. Intratumoral ERCC-1 gene expression was inversely related to progression-free survival and OS.

CONCLUSION

Neoadjuvant oxaliplatin, PI-FU, and EBRT for esophageal adenocarcinoma is active and tolerable. Because the regimen failed to meet the primary end point, it does not define a new standard. However, future trials can be built on this platform to validate the role of ERCC-1 in determining the best systemic regimen for individual patients.

Impact of young age on treatment efficacy and safety in advanced colorectal cancer: a pooled analysis of patients from nine first-line phase III chemotherapy trials

PURPOSE

Colorectal cancer predominantly occurs in the elderly, but approximately 5% of patients are 50 years old or younger. We sought to determine whether young age is prognostic, or whether it influences efficacy/toxicity of chemotherapy, in patients with advanced disease.

METHODS

We analyzed individual data on 6,284 patients from nine phase III trials of advanced colorectal cancer (aCRC) that used fluorouracil-based single-agent and combination chemotherapy. End points included progression-free survival (PFS), overall survival (OS), response rate (RR), and grade 3 or worse adverse events. Stratified Cox and adjusted logistic-regression models were used to test for age effects and age-treatment interactions.

RESULTS

A total of 793 patients (13%) were younger than 50 years old; 188 of these patients (3% of total patients) were younger than 40 years old. Grade 3 or worse nausea (10% v 7%; P = .01) was more common, and severe diarrhea (11% v 14%; P = .001) and neutropenia (23% v 26%; P < .001) were less common in young (younger than 50 years) than in older (older than 50 years) patients. Age was prognostic for PFS, with poorer outcomes occurring in those younger than 50 years (median, 6.0 v 7.5 months; hazard ratio, 1.10; P = .02), but it did not affect RR or OS. In the subset of monotherapy versus combination chemotherapy trials, the relative benefits of multiagent chemotherapy were similar for young and older patients. Results were comparable when utilizing an age cut point of 40 years.

CONCLUSION

Young age is modestly associated with poorer PFS but not OS or RR in treated patients with aCRC, and young patients have more nausea but less diarrhea and neutropenia with chemotherapy in general. Young versus older patients derive the same benefits from combination chemotherapy. Absent results of a clinical trial, standard combination chemotherapy approaches are appropriate for young patients with aCRC.

KRAS and colorectal cancer: ethical and pragmatic issues in effecting real-time change in oncology clinical trials and practice

Systemic therapy has led to a median survival time for patients with advanced colorectal cancer (CRC) almost fourfold longer than that expected with best supportive care, an outcome achieved through combining chemotherapeutic and targeted biologic agents. Although the latter can include anti-epidermal growth factor receptor antibodies, such as cetuximab and panitumumab, we now have strong evidence that patients whose tumors harbor mutated KRAS will not benefit from this class of agent. Acceptance of the reliability and importance of the KRAS data took several years to evolve, however, for a variety of reasons. The timeline from the presentation and publication of small, retrospective phase II studies to widespread acceptance of the KRAS predictive value and changes in behavior-specifically, modifications of ongoing national trials in advanced/metastatic CRC, changes in national guidelines and practice patterns, and adjustments to the labeled indications for the monoclonal antibodies-was lengthy. In this commentary, we discuss whether or not the process of data disclosure regarding KRAS status and treatment of advanced CRC patients was effective in permitting timely decisions regarding ongoing publicly funded clinical trials and whether or not such decisions were rational and ethical. The overall goals are to highlight lessons learned regarding early disclosure of clinical trial results, as well as vetting and adoption of new scientific data, and to propose modifications for handling similar situations in the future.

A USA registry of gastrointestinal stromal tumor patients: changes in practice over time and differences between community and academic practices

BACKGROUND

The objective of the study was to describe patterns of care of patients with gastrointestinal stromal tumors (GISTs) in the United States in the tyrosine kinase inhibitor (TKI) era.

PATIENTS AND METHODS

From November 2004 through March 2009, data were collected regarding demographics, diagnostic history, treatment, relapse, and survival of 882 patients with GIST from 122 community and academic medical practices.

RESULTS

The most common first-line treatment for the 719 patients presenting with localized GIST was surgery (87%). Use of adjuvant imatinib increased after June 2007; 47% of patients enrolled in the registry considered by the investigator to be at high risk for recurrence received adjuvant imatinib after June 2007 versus 18% before. Overall, 56% of patients received imatinib and 11% received sunitinib. The utilization of targeted therapy increased over time (45% and 0.4% of patients received imatinib and sunitinib, respectively, in 2006 versus 56% and 11%, respectively, in 2009).

CONCLUSIONS

These are the first GIST registry data from the TKI era. The use of targeted therapy for GIST has increased in accordance with updated treatment guidelines. Diagnosis of GIST has evolved with increased use of KIT testing. The duration of targeted therapy in the adjuvant therapy setting is similar in community and academic practices.

Cetuximab as second-line therapy in patients with metastatic esophageal adenocarcinoma: a phase II Southwest Oncology Group Study (S0415)

INTRODUCTION

Esophageal adenocarcinomas commonly express the epidermal growth factor receptor. This trial assessed the 6-month overall survival probability in metastatic esophageal cancer patients treated with cetuximab as second-line therapy.

METHODS

This was a multicenter, open-label phase II study of single-agent cetuximab for metastatic esophageal adenocarcinoma patients who failed one prior chemotherapy regimen. Adequate organ function and Zubrod performance status of 0 to 2 were required. Patients received cetuximab 400 mg/m intravenously (IV) on week 1 and 250 mg/m IV weekly thereafter. The primary objective was to determine 6-month overall survival. Secondary end points included progression-free survival, response rate, and toxicity. Tumor tissue was collected for correlative studies.

RESULTS

Sixty-three patients were registered, with eight ineligible or never treated. Fifty-five eligible patients (49 men, 6 women; median age = 61.2 years [range, 30.7-88.5]) were enrolled. Twenty patients survived more than 6 months for a 6-month overall survival rate of 36% (95% confidence interval [CI]: 24-50%). The median overall survival was 4.0 months (95% CI: 3.2-5.9). Median progression-free survival was 1.8 months (95% CI: 1.7-1.9). One partial response and two unconfirmed partial responses were observed. Two patients experienced grade 4 fatigue. There was one treatment-related death due to pneumonitis. Germline polymorphisms of epidermal growth factor receptor, epidermal growth factor, interleukin (IL)-8, cyclooxygenase (COX)-2, vascular epidermal growth factor receptor (VEGF), CCND1, neuropilin 1 (NRP1), and K-ras mutational status were not associated with response or survival.

CONCLUSIONS

The 6-month overall survival rate of 36% observed on this study failed to meet the primary survival objective. Thus, cetuximab alone cannot be recommended in the second-line treatment of metastatic esophageal cancer.

Phase III study comparing gemcitabine plus cetuximab versus gemcitabine in patients with advanced pancreatic adenocarcinoma: Southwest Oncology Group-directed intergroup trial S0205

PURPOSE

Patients with advanced pancreas cancer present with disease that is poorly responsive to conventional therapies. Preclinical and early clinical evidence has supported targeting the epidermal growth factor receptor (EGFR) signaling pathway in patients with pancreas cancer. This trial was conducted to evaluate the contribution of an EGFR-targeted agent to standard gemcitabine therapy. Cetuximab is a monoclonal antibody against the ligand-binding domain of the receptor.

PATIENTS AND METHODS

Patients with unresectable locally advanced or metastatic pancreatic adenocarcinoma were randomly assigned to receive gemcitabine alone or gemcitabine plus cetuximab. The primary end point was overall survival. Secondary end points included progression-free survival, time to treatment failure, objective response, and toxicity.

RESULTS

A total of 745 eligible patients were accrued. No significant difference was seen between the two arms of the study with respect to the median survival time (6.3 months for the gemcitabine plus cetuximab arm v 5.9 months for the gemcitabine alone arm; hazard ratio = 1.06; 95% CI, 0.91 to 1.23; P = .23, one-sided). Objective responses and progression-free survival were similar in both arms of the study. Although time to treatment failure was longer in patients on gemcitabine plus cetuximab (P = .006), the difference in length of treatment was only 2 weeks longer in the combination arm. Among patients who were studied for tumoral EGFR expression, 90% were positive, with no treatment benefit detected in this patient subset.

CONCLUSION

In patients with advanced pancreas cancer, the anti-EGFR monoclonal antibody cetuximab did not improve the outcome compared with patients treated with gemcitabine alone. Alternate targets other than EGFR should be evaluated for new drug development.

Pain and emotional well-being outcomes in Southwest Oncology Group-directed intergroup trial S0205: a phase III study comparing gemcitabine plus cetuximab versus gemcitabine as first-line therapy in patients with advanced pancreas cancer

PURPOSE

S0205 was a randomized clinical trial that compared the therapeutic impact of gemcitabine versus gemcitabine plus cetuximab. Study results for patient-reported health-related quality of life (HRQL) outcomes are reported.

PATIENTS AND METHODS

Patients completed the Brief Pain Inventory and a measure of emotional well-being (each measured on a 0 to 10 scale) at baseline and at weeks 5, 9, 13, and 17 postrandom assignment. Worst pain status was classified as palliated (worst pain scores < 5 maintained for 2 consecutive cycles) or not palliated (remaining patients) and tested with a chi(2) test. Change in emotional well-being and worst pain (exploratory analysis) were assessed over 17 weeks using generalized estimating equations with inverse probability of censoring weights.

RESULTS

Seven hundred twenty of 766 enrolled patients contributed baseline HRQL data. The two treatment arms did not differ statistically in the percentage of patients with successful worst pain palliation. Longitudinal analyses showed significantly improved emotional well-being for patients on both arms by weeks 13 and 17 (P < .01 and P < .001). An exploratory longitudinal analysis of worst pain showed significant decreases at all time points for both arms (P < .01 and P < .001). Significant treatment arm differences for either worst pain or emotional well-being were not observed at any of the assessment times.

CONCLUSION

We observed palliated pain and improved well-being for patients on this trial. However, these improvements were similar in both treatment arms, suggesting that the addition of cetuximab did not contribute to improvement in these HRQL outcomes.