Teresa Alonso

Influence of KRAS p.G13D Mutation in Patients With Metastatic Colorectal Cancer Treated With Cetuximab

BACKGROUND Patients with metastatic colorectal cancer (mCRC) with activating mutations at codon 12 or 13 of the KRAS gene are currently excluded from treatment with monoclonal antibodies against the epidermal growth factor receptor (EGFR), for example, cetuximab. Occasionally, some of these patients benefit from treatment with cetuximab, especially patients with a mutation at codon 13. We conducted an analysis to study the influence of the KRAS p.G13D mutation in patients with mCRC who were treated with cetuximab. MATERIALS AND METHODS We analyzed the KRAS mutation status of 110 patients who were treated with cetuximab between September 2003 and October 2008 at Hospital Clínico, San Carlos. We compared progression-free survival, overall survival, and response rate according to KRAS mutation status. RESULTS Patients with mutations at codon 13 compared with those with other KRAS mutations showed no statistically significant differences in progression-free survival (4.96 months [95% CI, 3.04-6.89 months] vs. 3.10 months [95% CI, 1.58-4.61 months]; hazard ratio [HR] 0.88 [95% CI, 44-1.75]; P = .72) and overall survival (8.2 months [95% CI, 4.2-12.1 months] vs. 14.6 months [95% CI, 8.0-21.2 months]; HR 0.50 [95% CI, 0.23-1.09]; P = .084). Patients with KRAS wild-type tumors have a longer progression-free survival (7.30 months [95% CI, 4.48-10.12 months]; HR 0.46 [95% CI, 0.23-0.91]; P = .025) and overall survival (19.0 months [95% CI, 10.2-27.8 months]; HR 0.32 [95% CI, 0.15-0.69]; P = .004) than patients with p.G13D-mutated tumors. Differences in the response rate were not observed between groups. CONCLUSION Patients with mCRC and mutation at codon 13 of the KRAS gene do not appear to benefit from treatment with cetuximab. These results support the current clinical practice.

Neuroendocrine Tumor Heterogeneity Adds Uncertainty to the World Health Organization 2010 Classification: Real‐World Data from the Spanish Tumor Registry (R‐GETNE)

BACKGROUND Gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) are a complex family of tumors of widely variable clinical behavior. The World Health Organization (WHO) 2010 classification provided a valuable tool to stratify neuroendocrine neoplasms (NENs) in three prognostic subgroups based on the proliferation index. However, substantial heterogeneity remains within these subgroups, and simplicity sometimes entails an ambiguous and imprecise prognostic stratification. The purpose of our study was to evaluate the prognostic impact of histological differentiation within the WHO 2010 grade (G) 1/G2/G3 categories, and explore additional Ki-67 cutoff values in GEP-NENs. SUBJECTS, MATERIALS, AND METHODS A total of 2,813 patients from the Spanish National Tumor Registry (RGETNE) were analyzed. Cases were classified by histological differentiation as NETs (neuroendocrine tumors [well differentiated]) or NECs (neuroendocrine carcinomas [poorly differentiated]), and by Ki-67 index as G1 (Ki-67 <2%), G2 (Ki-67 3%-20%), or G3 (Ki-67 >20%). Patients were stratified into five cohorts: NET-G1, NET-G2, NET-G3, NEC-G2, and NEC-G3. RESULTS Five-year survival was 72%. Age, gender, tumor site, grade, differentiation, and stage were all independent prognostic factors for survival. Further subdivision of the WHO 2010 grading improved prognostic stratification, both within G2 (5-year survival: 81% [Ki-67 3%-5%], 72% [Ki-67 6%-10%], 52% [Ki-67 11%-20%]) and G3 NENs (5-year survival: 35% [Ki-67 21%-50%], 22% [Ki-67 51%-100%]). Five-year survival was significantly greater for NET-G2 versus NEC-G2 (75.5% vs. 58.2%) and NET-G3 versus NEC-G3 (43.7% vs. 25.4%). CONCLUSION Substantial clinical heterogeneity is observed within G2 and G3 GEP-NENs. The WHO 2010 classification can be improved by including the additive effect of histological differentiation and the proliferation index. IMPLICATIONS FOR PRACTICE Gastroenteropancreatic neuroendocrine neoplasms are tumors of widely variable clinical behavior, roughly stratified by the World Health Organization (WHO) 2010 classification into three subgroups based on proliferation index. Real-world data from 2,813 patients of the Spanish Registry RGETNE demonstrated substantial clinical heterogeneity within grade (G) 2 and G3 neuroendocrine neoplasms. Tumor morphology and further subdivision of grading substantially improves prognostic stratification of these patients and may help individualize therapy. This combined, additive effect shall be considered in future classifications of neuroendocrine tumors and incorporated for stratification purposes in clinical trials.

Huge recurrent gastric neuroendocrine tumor: a second-line chemotherapeutic dilemma

Chemotherapy is considered “state of the art” for the treatment of poorly differentiated neuroendocrine neoplasms. Unfortunately, there is no standard effective post-first-line treatment for relapsing high-grade gastroenteropancreatic neuroendocrine neoplasms. We report the case of a patient with a gastric neuroendocrine carcinoma stage IV, with massive gastrointestinal bleeding at diagnosis. After the first line of platin-based chemotherapy a major tumoral response was documented, but the patient relapsed after 4 months. A second line of chemotherapy treatment was given, with the FOLFOX regimen, and the patient has been free of progression for almost 2 years. There is no second-line standard treatment accepted for this type of carcinoma, but 5-fluorouracil combined with oxaliplatin showed interesting antitumor activity.