IDH1 mutations in low-grade astrocytomas predict survival but not response to temozolomide

BACKGROUND

Mutations in isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) have been implicated in tumorigenesis of gliomas. Patients with high-grade astrocytomas with IDH1 or IDH2 mutations were reported to have a better survival, but it is unknown if this improved survival also holds for low-grade astrocytoma and whether these mutations predict outcome to specific treatment.

METHODS

We retrospectively investigated the correlation of IDH1 and IDH2 mutations with overall survival and response to temozolomide in a cohort of patients with dedifferentiated low-grade astrocytomas treated with temozolomide at the time of progression after radiotherapy.

RESULTS

IDH1 mutations were present in 86% of the 49 progressive astrocytomas. No mutations in IDH2 were found. Presence of IDH1 mutations were early events and significantly improved overall survival (median survival 48 vs 98 months), but did not affect outcome of temozolomide treatment.

CONCLUSION

These results indicate that IDH1 mutations identify a subgroup of gliomas with an improved survival, but are unrelated to the temozolomide response.

Somatostatin receptor in human hepatocellular carcinomas: biological, patient and tumor characteristics

BACKGROUND/AIM

The evidence on the efficacy of somatostatin analogues in the treatment of hepatocellular carcinoma (HCC) in humans is conflicting. A variety of human tumors demonstrate somatostatin receptors. All subtypes bind human somatostatin with high affinity, while somatostatin analogues bind with high affinity to somatostatin receptor subtype 2 (sst2). We investigated the sst2 expression in HCC and examined whether HCCs expressing sst2 are a distinct subgroup.

PATIENTS AND METHODS

Forty-five human HCCs were tested for sst2 expression and biological alterations. The proliferative capacity was determined with Ki67 immunostaining and the DNA ploidy status was measured by fluorescent in situ hybridization with a chromosome 1-specific repetitive DNA probe. Expression of tumor suppressor genes (p16, p53 and Rb1) was measured by immunohistochemistry.

RESULTS

sst2 expression was detected in 30 tumors (67%). No correlation existed between sst2 expression and the immunoprofiles of the tumor suppressor genes, aneuploidy, proliferation, age, gender, alpha-fetoprotein levels, tumor size, tumor grade and underlying liver disease.

CONCLUSION

In 67% of the patients with HCC, sst2 could be detected in the tumor. No clinical, pathological or biological characteristics were specific for sst2-positive tumors.

Long-term survival after radical resection for pancreatic head and ampullary cancer: a potential role for the EGF-R

BACKGROUND/AIM

Pancreatic cancer has a dismal prognosis. Ampullary cancer (defined as cancer of the ampulla of Vater or the distal common bile duct) has a better prognosis and is thought to be a biologically different tumor. The aim of this study was to find factors that could predict survival after radical (R-0) resection for pancreatic head and ampullary cancers.

METHODS

We analyzed clinical and pathological data from 93 patients who underwent a true R-0 resection for pancreatic head or ampullary cancer. Furthermore, we performed a tissue microarray protein expression analysis for several growth factor receptors and oncogenes: HER-2, EGF-R, ER, PR, C-myc, p53, p16, RB-1, and chromogranin A as a neuroendocrine differentiation marker.

RESULTS

Median survival (14 vs. 42 months) and time to recurrence (16 vs. 42 months) were significantly longer for ampullary than for pancreatic head cancers. Preoperative pain, perineural invasion, lymph node metastasis, and tumor differentiation grade are indicators of a poor survival. No differences in protein expression were found between groups, except for EGF-R which was expressed more in pancreatic head cancers (p = 0.026).

CONCLUSIONS

Outcomes for ampullary cancers are better than for pancreatic head cancers. This different biological behavior can possibly be explained by differences in EGF-R expression.