Background:Trastuzumab has recently shown efficacy in the treatment of HER2-positive advanced gastric adenocarcinoma. Although antibody-based therapies target the metastatic disease, HER2 status is usually evaluated in the primary tumour because metastatic sites are rarely biopsied. The aim of this study was to compare HER2 status in primary and paired metastatic sites of gastric adenocarcinoma.Methods:The HER2 status was assessed by fluorescence in situ hybridisation (FISH) and immunohistochemistry (IHC) in 72 secondary lesions of gastric adenocarcinoma and in the corresponding primary tumours.Results:Concordance of FISH results, evaluable in 68 primary and matched metastatic sites, was 98.5%. Concordance of IHC results, available in 39 of the 72 paired cases, was 94.9%. Only one case showed discordance between primary tumour and metastasis, being negative by both IHC and FISH in the primary and showing HER2 overexpression and amplification in the corresponding pancreatic lymph node metastasis.Conclusion:The high concordance observed between HER2 results obtained by both IHC and FISH on primary tumours and corresponding metastases suggests that in gastric cancer HER2 status is maintained in most cases unchanged during the metastatic process.

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We analysed the expression of microsatellite instability, p53, p21, vascular endothelial growth factor and thymidylate synthase (TS) in pretreatment biopsy specimens from 57 locally advanced rectal cancers. The aim of the study was to correlate the expression of these markers with pathological response. Nineteen patients were treated with preoperative concomitant radiotherapy (RT) and fluorouracil/oxaliplatin-based chemotherapy (RCT), while 38 had RT alone. Pathological complete remission (pCR) and microfoci residual tumour (micR) occurred more frequently in patients treated with RCT (P ¼ 0.002) and in N0 tumours (P ¼ 0.004). Among patients treated with RCT, high TS levels were associated with a higher response rate (pCR þ micR; P ¼ 0.015). No such correlation was found in the RT group. The other molecular factors were of no predictive value. Multivariate analysis confirmed a significant interaction between nodal status and the probability of achieving a pathological response (P ¼ 0.023) and between TS expression and treatment, indicating that a high TS level is predictive of a higher pathological response in the RCT subset (P ¼ 0.007). This study shows that lymph node status is the most important predictive factor of tumour response to preoperative treatment. Thymidylate synthase expression assessed immunohistochemically from pretreatment tumour biopsies may be a useful predictive marker of rectal tumour response to preoperative RCT.

The endoscopic approach has gained an increased popularity in recent years for the biopsy and, in selected cases, the removal of tumors of the posterior third ventricle and pineal region. The authors report their experience on a series of 20 patients discussing also the technical limitations and complication avoidance. This is a prospective study of 20 patients with posterior third ventricle and pineal region tumors surgically managed by endoscopic biopsy and/or excision and simultaneous third ventriculostomy. The removal of the lesion could be achieved in 12 cases whereas in 8, only a biopsy could be performed. A histological diagnosis could be obtained in all cases. No delayed third ventricular stoma failures were recorded in any patient at the latest follow-up (mean follow-up, 39 months). Severe postoperative complications were recorded in 2 out of 12 cases of tumor removal attempt and in zero out of eight cases of biopsy. A delayed (3 weeks) postoperative mortality occurred in a patient harboring a GBM that developed an intratumoral hematoma 48 h postoperatively, one patient was in a vegetative state. Transient postoperative complications included: nausea and vomiting (five cases) and diplopia (two cases). One patient developed a bilateral ophthalmoplegia that recovered within 6 months due to residual tumor hemorrhage. Higher rate of complications was found in the case of vascularized and/or larger lesions. Endoscopic management of posterior third ventricle lesions may represent an effective option. However, though biopsies remain often a safe procedure, tumor excision should be limited to highly selected cases (cystic, poorly vascularized, and/or smaller than 2.5-cm lesions).

BACKGROUND: Loss of phosphatase and tensin homologue deleted in chromosome 10 (PTEN) function in advanced colorectal cancer (CRC) may represent one of the resistance mechanisms to cetuximab by interfering with the epidermal growth factor receptor signal transduction pathway. METHODS: PTEN expression tested by indirect immunofluorescence was evaluated both on primary (n ¼ 43) and on metastatic (n ¼ 24) sites in CRC patients treated with cetuximab. RESULTS: The loss of PTEN expression tested on metastatic sites was negatively associated with response (100% progressive disease (PD) in PTEN-negative cases vs 30% PD in PTEN-positive cases; Po0.05), PFS (0.8 vs 8.2 months; Po0.001) and OS (2.9 vs 14.2 months; Po0.001). CONCLUSION: A potential role of PTEN in the anti-tumour activity of cetuximab could be hypothesised.