[HER2 (neu/c-erbB-2) is a member of the EGF receptor family. It is activated without binding a specific ligand that leads to malignant transformation and tumor progression. Overexpression of HER2 is detected in approximately one quarter of human breast cancers. Immunohistochemistry and in situ hybridization (FISH) are the most widely used techniques in studying HER2 expression. HER2 positivity indicates worse outcome in node positive breast cancer and increasing number of studies show unfavourable prognosis in node negative cases as well. Recent data indicate that the knowledge of HER2 status may promote therapeutic decision. The generally applied cyclophosphamide- methotrexate-5-fluorouracil (CMF) polychemotherapy seems to provide no benefit in HER2 positive cases in contrast with HER2 negative breast cancer patients. Interestingly, doseintensive doxorubicin based chemotherapy gives better results in HER2 positive than in HER2 negative tumors. Determination of HER2 expression has great importance before therapeutic application of the humanized antibody trastuzumab (Herceptin). HER2 overexpression usually correlates well with estrogen and progesterone receptor negativity and hormone-resistance, therefore hormonal therapy is not justified for these patients. Some experimental and clinical data indicate that in case of simultaneous HER2 and ER positivity tamoxifen worsens treatment results which may be prevented by the coadministration of tamoxifen and trastuzumab. Emerging experimental and clinical data about HER2 has led to a new stage of individual treatment of breast cancer patients. The knowledge of HER2 status promotes antitumor intervention based on molecular characteristics of breast cancers. Therefore, reliable HER2 tests are needed in the everyday practice.]

[Vitrectomy is a closed microsurgical technique, by which intraocular tissue, blood and foreign bodies can be removed through a small incision in the pars plana with an automated suction-cutting device (vitrectom), while maintaining normal or slightly elevated intraocular pressure. This technique requires many accessory instruments (microscope, endoillumination, intraocular instruments, endolaser). The main application of vitrectomy is the treatment of severe complications in diabetes mellitus: diabetic retinopathy in the proliferative stage. Vitrectomy is indicated in diabetic retinopathy for the removal of intraocular bleeding and for the treatment of complications of diabetic proliferative vitreoretinopathy (recurring bleeding, tractional and rhegmatogenous retinal detachment). In the case of intraocular bleeding, early vitrectomy is better than delayed, providing good visus (V: 0,5) in 25% of all patients (based on literature data). In retinal detachment cases of tractional origin, surgery provides satisfactory visus for self-care in 2/3rd of all patients.]