High-density SNP arrays improve detection of HER2 amplification and polyploidy in breast tumors.

BACKGROUND: Human epidermal growth factor receptor-2 (HER2) overexpression and gene amplification are currently established by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), respectively. This study investigates whether high-density single nucleotide polymorphism (SNP) arrays can provide additional diagnostic power to assess HER2 gene status. METHODS: DNA from 65 breast tumor samples previously diagnosed by HER2 IHC and FISH analysis were blinded and examined for HER2 copy number variation employing SNP array analysis. RESULTS: SNP array analysis identified 24 (37%) samples with selective amplification or imbalance of the HER2 region in the q-arm of chromosome 17. In contrast, only 15 (23%) tumors were found to have HER2 amplification by IHC and FISH analysis. In total, there was a discrepancy in 19 (29%) samples between SNP array and IHC/FISH analysis. In 12 of these cases, the discrepancy towards FISH could be attributed to concomitant amplification or deletion of the centromeric region, which harbors the FISH reference probe sequence. In 3 tumors, repeated IHC/FISH analysis revealed that the original IHC/FISH analysis had failed to indicate the correct HER2 expression level. Finally, the SNP array analysis revealed that more than two thirds of the samples exhibited polyploidy that was unrecognized by conventional FISH. CONCLUSIONS: Collectively, the data show that determination of HER2 copy number variations by SNP array-based genomic segmentation analysis is an effective supplement to IHC/FISH HER2 analysis that, by providing additional diagnostic sensitivity and accuracy, may elect more women for targeted treatment with HER2 inhibitors.

Follicular lymphoma of the ocular adnexal region: a nation-based study.

PURPOSE: To characterize the clinicopathological features of follicular lymphoma of the ocular adnexal region. METHODS: Retrospective nation-based study of Danish patients with ocular adnexal follicular lymphoma from January 1st 1980 through December 31st 2009. RESULTS: Twenty-four patients with ocular adnexal follicular lymphoma were identified. Fourteen (58%) of the patients were females. The median age was 63 years (range: 42-96 years). Eleven (46%) of the patients had primary ocular adnexal lymphoma, seven (29%) had an ocular adnexal lesion in conjunction with a concurrent systemic lymphoma and six patients (25%) presented with an ocular adnexal relapse. The most frequently affected sites were the lacrimal gland (38%) and the orbit (33%). Thirteen patients (54%) presented with Ann Arbor stage IE lymphoma, four (17%) had stage IIE, two patients (8%) stage IIIE, and five patients (21%) had stage IV lymphoma. Radiotherapy was primarily used in patients with primary lymphoma and those with a stage IE/IIE relapse (82%), while stage IIIE/IV lymphomas most frequently received alkylating chemotherapy (67%). Complete remission was observed in 19 of the patients (79%), but of these 11(58%) had a relapse. The 10-year overall survival for the entire cohort was 59%. The translocation t(14;18) was detected in 16 patients (16/24, 76%). Recurrence was only observed in patients with the t(14;18) (p=0.05, log-rank). CONCLUSIONS: Ocular adnexal follicular lymphoma is more commonly found in elderly female patients. The lacrimal gland is relatively frequently involved. Radiotherapy is the treatment of choice for localized ocular adnexal follicular lymphoma providing a favourable prognosis for majority of patients.

Concomitant occurrence of EGFR (epidermal growth factor receptor) and KRAS (V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog) mutations in an ALK (anaplastic lymphoma kinase)-positive lung adenocarcinoma patient with acquired resistance to crizotinib: a case report.

BACKGROUND: Anaplastic lymphoma kinase-positive non-small cell lung carcinoma patients are generally highly responsive to the dual anaplastic lymphoma kinase and MET tyrosine kinase inhibitor crizotinib. However, they eventually acquire resistance to this drug, preventing the anaplastic lymphoma kinase inhibitors from having a prolonged beneficial effect. The molecular mechanisms responsible for crizotinib resistance are beginning to emerge, e.g., in some anaplastic lymphoma kinase-positive non-small cell lung carcinomas the development of secondary mutations in this gene has been described. However, the events behind crizotinib-resistance currently remain largely uncharacterized. Thus, we report on an anaplastic lymphoma kinase-positive non-small cell lung carcinoma patient with concomitant occurrence of epidermal growth factor receptor and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutations upon development of crizotinib-resistance. CASE PRESENTATION: A 61-year-old Caucasian never-smoking male was diagnosed with anaplastic lymphoma kinase -positive pulmonary adenocarcinoma, stage T4N3M1b. Treatment with crizotinib initially resulted in complete objective response in the thorax and partial response in the abdomen, but after 8 months of therapy the patient acquired resistance and progressed. Biopsies from new metastases revealed development of epidermal growth factor receptor and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog mutations concomitant with the original anaplastic lymphoma kinase gene rearrangement and without signs of anaplastic lymphoma kinase fusion gene amplification or secondary anaplastic lymphoma kinase mutations. CONCLUSION: To our knowledge, this is the first report of an anaplastic lymphoma kinase-positive pulmonary adenocarcinoma, which upon emergence of crizotinib resistance acquired 2 new somatic mutations in the epidermal growth factor receptor and V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog genes, respectively, concomitant with the original anaplastic lymphoma kinase rearrangement. Thus, these 3 driver mutations, usually considered mutually exclusive, may coexist in advanced non-small cell lung carcinoma that becomes resistant to crizotinib, presumably because heterogeneous tumor clones utilize epidermal growth factor receptor and/or V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog signaling to circumvent the inhibition of anaplastic lymphoma kinase-mediated signaling by crizotinib. The identification of new targetable somatic mutations by tumor re-biopsy may help clarify the mechanism behind the development of the acquired crizotinib resistance and pave the way for combined strategies involving multiple targeted therapies.