Bevacizumab + capecitabine as maintenance therapy after initial bevacizumab + XELOX treatment in previously untreated patients with metastatic colorectal cancer: phase III 'Stop and Go' study results--a Turkish Oncology Group Trial.

OBJECTIVE: It was the aim of this study to evaluate maintenance therapy with bevacizumab + capecitabine following induction with bevacizumab + capecitabine + oxaliplatin (XELOX) versus bevacizumab + XELOX until progression as first-line therapy in metastatic colorectal cancer (mCRC). METHODS: Patients received either bevacizumab (7.5 mg/kg) + XELOX (capecitabine 1,000 mg/m(2) twice daily on days 1-14 + oxaliplatin 130 mg/m(2) on day 1 every 3 weeks) until disease progression (arm A) or the same doses of bevacizumab + XELOX for 6 cycles followed by bevacizumab + capecitabine until disease progression (arm B). The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), objective response rate (ORR) and safety. RESULTS: One hundred and twenty-three patients were randomized. Treatment compliance was similar in both groups. Median PFS was significantly longer for arm B than for arm A (11.0 vs. 8.3 months; p = 0.002). There was no significant difference between the two arms for ORR (66.7 vs. 59.0%; p = 0.861) or median OS (23.8 vs. 20.2 months; p = 0.100). Tolerability was acceptable in both treatment arms; the most frequent grade 3/4 treatment-related adverse events (arm B vs. arm A) were fatigue (6.6 vs. 16.1%), diarrhoea (3.3 vs. 11.3%), anorexia (3.3 vs. 11.3%), and neuropathy (1.6 vs. 8.1%). CONCLUSIONS: Maintenance therapy with bevacizumab + capecitabine can be considered an appropriate option following induction bevacizumab + XELOX in patients with mCRC instead of continuation of bevacizumab + XELOX.

Inhibitory effect of 5-fluorouracil on cytochrome P450 2C9 activity in cancer patients.

Drug interactions have been reported between 5-fluorouracil and cytochrome P450 2C9 (CYP2C9) substrates, S-warfarin and phenytoin. This study was performed to determine the influence of 5-fluorouracil on cytochrome P450 2C9 (CYP2C9) activity in colorectal cancer patients (n=17) receiving 5-fluorouracil. Losartan was used as a marker to assess CYP2C9 activity. Losartan and its CYP2C9 dependent metabolite, E-3174, were determined in urine. The ratios of urinary losartan/E-3174 before and after the 5-fluorouracil treatment were compared for each patient. Genotyping was performed to detect the CYP2C9*2 and CYP2C9*3. At the end of the first cycle of 5-fluorouracil, losartan/E-3174 ratio was increased by 28.0% compared to the pre-treatment values (P=0.15). In five patients recruited for phenotyping after three 5-fluorouracil cycles, the metabolic ratio was increased significantly by 5.3 times (P=0.03). The results suggest that in most patients 5-fluorouracil inhibited CYP2C9 activity. This inhibition was more pronounced when the total administered dose increased. This finding may help explain the mechanism of interaction between 5-fluorouracil and CYP2C9 substrates.

Metastatic gastrointestinal stromal tumor with long-term response after treatment with concomitant radiotherapy and imatinib mesylate.

Total surgical excision of the tumor is considered to be the only hope in treatment of malignant mesenchymal tumors. The roles of radiotherapy and/or chemotherapy have not yet been established. We report here a case of metastatic gastrointestinal stromal tumors with a dramatic long duration of response after treatment with concurrent radiotherapy and imatinib mesylate. The patient had a long-term complete response at the radiotherapy region with concomitant imatinib therapy although previous metastatic sides persisted with partial response.

Synchronous presentation of nasopharyngeal and renal cell carcinomas.

We report a rare case of synchronous presentation of nasopharyngeal and renal cell carcinomas in a-50-year old male patient with long standing smoking history. The patient was initially presented with a diagnosis of nasopharyngeal carcinoma. During staging process, the abdominal computed tomography detected a right renal solid mass, 6.5 cm in diameter, originating from posterior portion of the right renal cortex. Right radical nephrectomy was performed and pathological examination revealed renal cell carcinoma. Smoking was thought to be a risk factor for both cancers. Systemic evaluation of kidney should not be discarded in patients diagnosed with nasopharyngeal carcinoma living in western countries with a smoking history.

Synchronous presentation of nasopharyngeal and renal cell carcinomas

We report a rare case of synchronous presentation of nasopharyngeal and renal cell carcinomas in a-50-year old male patient with long standing smoking history. The patient was initially presented with a diagnosis of nasopharyngeal carcinoma. During staging process, the abdominal computed tomography detected a right renal solid mass, 6.5 cm in diameter, originating from posterior portion of the right renal cortex. Right radical nephrectomy was performed and pathological examination revealed renal cell carcinoma. Smoking was thought to be a risk factor for both cancers. Systemic evaluation of kidney should not be discarded in patients diagnosed with nasopharyngeal carcinoma living in western countries with a smoking history.