Tomaž Rott

Postoperative radiotherapy for radically resected N2 non-small-cell lung cancer (NSCLC): randomised clinical study 1988–1992

In the period 1988-1992, 74 consecutive radically resected patients with NSCLC were randomised to postoperative radiotherapy or surgery alone in order to evaluate the influence of postoperative radiotherapy on survival. There were 61 males and 13 females, aged 35-80 years, median 59 years. Their distribution by stage was as follows: pT1N2 = 19, pT2N2 = 54, pT3N2 = one patient; histology: 32 squamous, 32 adeno and 10 large cell carcinomas; surgery: atypical resection in six, lobectomy in 27, bilobectomy in ten, and pneumonectomy in 31 patients. In 27 patients, only one lymph node in a single mediastinal lymph node site was affected; in 31 patients more than one lymph node in one site; in 16 patients more sites were affected. In 35/74 patients radiotherapy of hilar and mediastinal sites with 3000 cGy in 2 weeks was performed. On December 31, 1994, 19 patients (26%) were still alive; 39/55 patients died of the following causes: locoregional failure-10(26%), distant metastases- 25 (64%), other tumor-unrelated causes-four patients (10%). Five-year survival rates did not show statistically significant differences between the irradiated and surgically treated patients only with respect to sex, pTNM stage, histology and frequency of locoregional failure. The number of metastatic mediastinal lymph nodes was the only significant prognostic factor (P < 0.005) in both randomised groups.

Frequent polymorphic variations but rare tumour specific mutations of the S100A2 on 1q21 in non-small cell lung cancer.

Contrary to the recent hypothesis that S100A2 is a tumour suppressor, no somatic mutations have yet been identified. We therefore screened 90 non-small cell lung carcinoma (NSCLC) samples, initially for mutations in S100A2 and then also for mutations in P53 and K-RAS genes. Alterations were detected in 46.7% of squamous lung cancer (SCC) samples, but we detected only one novel tumour specific mutation, Q23X in squamous carcinoma. We detected four polymorphisms, two of them published for the first time (144+109 C/G and 297+75A/G) and two already published: S62N, in the coding region and related to squamous cell carcinoma (SCC), and 297+17T/C. Analysis of S100A2 expression revealed that expression in adenocarcinomas and squamous cell carcinomas is significantly different, but not related to any of the found alterations. In one tumour with S62N polymorphism, P53 and K-RAS genes were also mutated, while two tumours with the Q23X mutation have a P53 but no K-RAS mutation. To the best of our knowledge, this is the first report describing alterations in the S100A2 gene proving a relation between changes in predominantly squamous lung cancer.

Interstitial Capillary in Normal and in Transplanted Kidneys: An Ultrastructural Study

Knowledge about the normal structure and pathology of interstitial capillary is limited. Splitting and multilayering of the basal membrane (BM), as a marker of chronic rejection, has been published in association with transplant glomerulopathy. The authors investigated the ultrastructural features of the interstitial capillary basal membrane in normal (15 biopsies) and in transplanted kidneys (27 biopsies from 21 patients), expressing transplant glomerulopathy (8 biopsies from 6 patients), acute tubulo-interstitial rejection (9 biopsies from 6 patients), and recurrent or de novo glomerulonephritis (10 biopsies from 8 patients). All biopsies were fixed in 1%OsO 4, embedded in Epon, and examined by electron microscope. Measurements of the interstitial capillary BM were made. The BM of interstitial capillary of intact kidney was a homogenous continuous structure, 88 nm in width on average. Thickening with diffuse multilayering of BM was most intensive in patients with transplant glomerulopathy, and much less intensive in patients with acute tubulointerstitial rejection and in patients with recurrent or de novo glomerulonephritis. These findings may provide the first information about the morphology of the normal basal lamina of interstitial capillary and support the diagnostic value of interstitial capillary changes in chronic rejection.

Peritubular Capillary Changes in Alport Syndrome, Diabetic Glomerulopathy, Balkan Endemic Nephropathy and Hemorrhagic Fever with Renal Syndrome

The morphology of peritubular capillary has been mostly studied in relation to chronic transplant rejection, where an association has been found between transplant glomerulopathy and reduplication of peritubular capillary basement membranes (PCBM). This electron microscopy study of peritubular capillaries was done on kidney biopsies performed on patients with conditions involving primarily glomeruli (diabetic glomerulopathy (23), Alport syndrome (37)) or causing more or less isolated changes of nephron structures outside the glomeruli (Balkan endemic nephropathy (15) and hemorrhagic fever with renal syndrome (19)). The aim was to explore the ultrastructural features of the PCBM. In patients with diabetic glomerulopathy, the PCBM was homogeneous, with a width ranging from normal to evidently increased (55–355 nm). In patients with Alport syndrome, the PCBM was homogeneous, with no substantial splitting or prominent thickening. Mean thickness varied between 80 (85–100) nm in children and 120 (46–250) nm in adults. Mean PCBM thickness in patients with Balkan endemic nephropathy was 209 (90–1270) nm. The thickened PCBM was also often split. In patients with hemorrhagic fever with renal syndrome, peritubular capillaries and medular vasa recta were generally extremely congested and focally ruptured, and their basal lamina showed prevailing thinning and focal discontinuities.

Fire-eater's lung complicated by an infectious abscess requiring surgical treatment

We describe a case of fire‐eaters pneumonia that was complicated by an infectious lung abscess with substantial haemoptysis. Conservative treatment was inadequate. Surgical resection was necessary and proved to be successful.

K-RAS and P53 mutations in association with COX-2 and hTERT expression and clinico-pathological status of NSCLC patients

We evaluated the occurrence of mutations in P53, K-RAS, COX-2, expression of COX-2 and hTERT and relations among clinicopathological signs. P53 mutations were identified in 34.4% of tumours, the majority of them occurring in SCC (squamous cell carcinoma, 55.6%). K-RAS was mutated in 12.2% of NSCLC tumours, the majority of the mutations being found in ADC (adenocarcinoma, 27.0%). Mutational screening detected three different COX-2 mutations and five different P53 mutations, published for the first time. With RT-PCR we observed that the expression of the tested genes, hTERT and COX-2, was highly significant for ADC (p < 0.01) and SCC (p < 0.05). Statistical analysis of the combined results revealed significant correlation between expression of COX-2 and hTERT (p < 0.001), hTERT expression and staging (p < 0.05) and survival (p < 0.01). A positive correlation between COX-2 expression and K-RAS mutation (p <0.05) was also observed. This study provides insight into associations between the analysed biomarkers and the clinical-pathological data of the patients.

Influence of heat-based antigen retrieval (HBAR) on possible false-positive immunoreactivity

Abstract Immunohistochemistry is the most helpful ancillary method used in routine biopsy diagnostics. Its results are influenced by fixation of the tissue specimens, absolute level of the antigen, affinity and concentrations of the primary antibodies, duration of incubation, sensitivity of the immunohistochemic (IH) method, and also by antigen unmasking technique. Heat-based antigen retrieval (HBAR) and more sensitive IH techniques may lead to false positive results. They may be sometimes hardly differentiated from unexpected true positive IH results in some unusual, rare and undifferentiated tumours. To avoid false positive IH results, standardisation of all steps in methodology should be applied, including HBAR. pH of the antigen retrieval solution, heating time and temperature, and also the concentrations of each primary antibody should be properly determined. If very high working dilutions of antibodies are demanded, the use of a less sensitive IH method is recommended. For illustration, an oncocytic lung tumour in a 77-year-old male with false-positive IH results is presented, when antigen retrieval solution, pH 9.9, was applied. But it disappeared at the higher primary antibodies’ concentrations, using retrieval solution, pH 6.0.