Association KRAS G13D tumor mutated outcome in patients with chemotherapy refractory metastatic colorectal cancer treated with cetuximab.

BACKGROUND/AIMS: Cetuximab is currently approved for the treatment of metastatic colorectal cancer (mCR) with KRAS wild-type. Prior few studies demonstrated that G13D mutated tumors could benefit from cetuximab. This study aims to investigate whether KRAS G13D mutated tumors benefit from cetuximab in the chemotherapy refractory patients. METHODOLOGY: We retrospectively compared progression-free survival (PFS), overall survival (OS) and response rate (RR) according to KRAS mutation status in 105 patients with mRC treated at the Cerrahpasa Medical School Hospital, between October 2008 and October 2011, with cetuximab alone or in combination with chemotherapy. RESULTS: PFS was significantly longer in patients G13D mutated tumors (6.81 months) than in patients with other KRAS mutated tumors (5 months) (p=0.027). No significant difference in PFS between patients G13D mutated and KRAS wild-type tumors was detected. No significant difference in OS was detected in patients between G13D mutated tumors and other KRAS mutated tumors. However, patients with KRAS wild-type tumors had significantly longer OS (16.1 months) than patients with mutated tumors (8.9 months) (p=0.025). RR in patients with other KRAS mutated tumors, was significantly worse than those with G13D mutated tumors (p=0.002). CONCLUSION: Our study demonstrated an association between the presence KRAS G13D mutanted and survival chemotherapy in refractory metastatic colorectal cancer treated with cetuximab.

Gastroenteropancreatic neuroendocrine tumors: 10-year experience in a single center.

Neuroendocrine tumors originate from neuroendocrine cells and occur in a wide spectrum from carcinoid tumors to small cell carcinomas. Although the World Health Organization determined clinical and histological features to predict prognosis for such tumors, they may not be valid on an individual basis. This study investigates the clinical, pathologic and prognostic characteristics of gastroenteropancreatic neuroendocrine tumors that presented to the Medical Oncology Outpatient Clinic, Istanbul University, Cerrahpasa School of Medicine from 1995 to 2006 (n=86). The mean age of the patients was 52±14 and the male-to-female ratio was 0.87. The most common site of involvement was the stomach. Midgut intestinal tumors seemed to have significant female predominance compared to hindgut intestinal tumors (P=0.016). Most of the patients had metastatic disease with a prevalence of 34.9%. Poorly differentiated tumors and mixed neuroendocrine carcinomas were significantly larger than 2 cm (P=0.0001). The median survival was 139 months and the highest mortality was for colorectal tumors (36%). While univariate analysis revealed that the number of lymph nodes (P=0.008), multiple foci (P=0.034), metastases (P=0.022) and stage (P=0.034) correlated significantly with survival, there was no independent variable in the multivariate analysis. Hindgut tumors had significantly more Ki-67, mitosis and necrosis compared to others (P≤0.05). In this retrospective study, the clinical, pathologic and prognostic characteristics of gastroenteropancreatic tumors from a single center from Turkey were analyzed and compared with the current medical literature.

Thymoma with chronic diarrhea: report of two cases and review of the literature.

Thymoma associated with hypogammaglobulinemia and profound susceptibility to recurrent and serious infections was first reported by Good in 1954, after whom it was named as Good's syndrome. Chronic diarrhea associated with thymoma is almost always seen in patients with hypogammaglobulinemia. However, chronic diarrhea in a setting of normal gammaglobulins have been rarely reported. We hereby report two cases of thymoma with normal immune functions, presenting with chronic diarrhea as the only symptom of thymic malignancy. We discussed the etiopathogenic relation between thymic pathology and diarrhea and review the cases of thymoma associated with chronic diarrhea in the English literature.