The genomic expression test EndoPredict is a prognostic tool for identifying risk of local recurrence in postmenopausal endocrine receptor-positive, her2neu-negative breast cancer patients randomised within the prospective ABCSG 8 trial.

BACKGROUND: The aim of this study was to examine whether EndoPredict (EP), a novel genomic expression test, is effective in predicting local recurrence (LR)-free survival (LRFS) following surgery for breast cancer in postmenopausal women. In addition, we examined whether EP may help tailor local therapy in these patients. METHODS: From January 1996 to June 2004, 3714 postmenopausal patients were randomly assigned to either tamoxifen or tamoxifen followed by anastrozole within the prospective ABCSG 8 trial. Using assay scores from EP, we classified breast tumour blocks as either low or high risk for recurrence. RESULTS: Data were gathered from 1324 patients. The median follow-up was 72.3 months and the cumulative incidence of LR was 2.6% (0.4% per year). The risk of LR over a 10-year period among patients with high-risk lesions (n=683) was significantly higher (LRFS=91%) when compared with patients with low-risk lesions (n=641) (10-year LRFS=97.5%) (HR: 1.31 (1.16-1.48) P<0.005). The groups that received breast conservation surgery (BCT) and mastectomy (MX) had similar LR rates (P=0.879). Radiotherapy (RT) after BCT significantly improved LRFS in the cohorts predicted by EP to be low-risk for LR (received RT: n=436, 10-year LRFS 99.8%; did not receive RT: n=63, 10-year LRFS 83.6%, P<0.005). CONCLUSIONS: EndoPredict is an effective prognostic tool for predicting LRFS. Among postmenopausal, low-risk patients, EP does not appear to be useful for tailoring local therapy.

The EndoPredict score provides prognostic information on late distant metastases in ER+/HER2- breast cancer patients.

BACKGROUND: ER+/HER2- breast cancers have a proclivity for late recurrence. A personalised estimate of relapse risk after 5 years of endocrine treatment can improve patient selection for extended hormonal therapy. METHODS: A total of 1702 postmenopausal ER+/HER2- breast cancer patients from two adjuvant phase III trials (ABCSG6, ABCSG8) treated with 5 years of endocrine therapy participated in this study. The multigene test EndoPredict (EP) and the EPclin score (which combines EP with tumour size and nodal status) were predefined in independent training cohorts. All patients were retrospectively assigned to risk categories based on gene expression and on clinical parameters. The primary end point was distant metastasis (DM). Kaplan-Meier method and Cox regression analysis were used in an early (0-5 years) and late time interval (>5 years post diagnosis). RESULTS: EP is a significant, independent, prognostic parameter in the early and late time interval. The expression levels of proliferative and ER signalling genes contribute differentially to the underlying biology of early and late DM. The EPclin stratified 64% of patients at risk after 5 years into a low-risk subgroup with an absolute 1.8% of late DM at 10 years of follow-up. CONCLUSION: The EP test provides additional prognostic information for the identification of early and late DM beyond what can be achieved by combining the commonly used clinical parameters. The EPclin reliably identified a subgroup of patients who have an excellent long-term prognosis after 5 years of endocrine therapy. The side effects of extended therapy should be weighed against this projected outcome.

EndoPredict improves the prognostic classification derived from common clinical guidelines in ER-positive, HER2-negative early breast cancer.

BACKGROUND: In early estrogen receptor (ER)-positive/HER2-negative breast cancer, the decision to administer chemotherapy is largely based on prognostic criteria. The combined molecular/clinical EndoPredict test (EPclin) has been validated to accurately assess prognosis in this population. In this study, the clinical relevance of EPclin in relation to well-established clinical guidelines is assessed. PATIENTS AND METHODS: We assigned risk groups to 1702 ER-positive/HER2-negative postmenopausal women from two large phase III trials treated only with endocrine therapy. Prognosis was assigned according to National Comprehensive Cancer Center Network-, German S3-, St Gallen guidelines and the EPclin. Prognostic groups were compared using the Kaplan-Meier survival analysis. RESULTS: After 10 years, absolute risk reductions (ARR) between the high- and low-risk groups ranged from 6.9% to 11.2% if assigned according to guidelines. It was at 18.7% for EPclin. EPclin reassigned 58%-61% of women classified as high-/intermediate-risk (according to clinical guidelines) to low risk. Women reclassified to low risk showed a 5% rate of distant metastasis at 10 years. CONCLUSION: The EPclin score is able to predict favorable prognosis in a majority of patients that clinical guidelines would assign to intermediate or high risk. EPclin may reduce the indications for chemotherapy in ER-positive postmenopausal women with a limited number of clinical risk factors.

[Uncommon cystic appearance of lymph nodes in malignant lymphoma]. / Aussergewöhnlich zystisches Erscheinungsbild von Lymphknoten bei malignem Lymphom.

Sonographic examination of the abdomen and of superficial lymph nodes in a patient with weight loss and rectal bleeding showed numerous lymph nodes with partially cystic areas. Biopsy and histological examination revealed mantle cell lymphoma. Additional staining with immunological markers confirmed the diagnosis of cystic transformation of the lymph node sinuses.

Novel approach of human epidermal growth factor receptor 2 detection in noninvasive and invasive transitional cell carcinoma of the bladder.

PURPOSE: In recent years over expression of HER2 has been identified in malignant tumors of organs other than breast. Studies of bladder carcinoma that analyzed HER2 protein expression and gene amplification with a variety of nonstandardized methods have shown heterogeneous results. The results reported vary from 2% to 74% of protein over expression, to 4% to 59% of gene amplification of HER2, possibly due to differences in study design, material selection or laboratory methodology. MATERIALS AND METHODS: In the present study archival tissue from 87 patients with noninvasive papillary (25) and invasive (62) TCC was analyzed for amplification of the HER2 gene and over expression of its encoded protein. HER2 protein expression was detected by immunohistochemistry using the HercepTest. Routinely processed paraffin embedded tissue was investigated for HER2 gene amplification using CISH and FISH. RESULTS: Of the invasive 37 (58%) and of the noninvasive 19 (76%) transitional cell carcinomas investigated showed over expression of the HER2 protein (3+ and 2+) using a standardized immunohistochemical method. HER2 gene amplification assays performed on positive cases evaluated by immunohistochemistry were obtained in 81% and 43% of 3+ and 2+ HER2 protein over expressing invasive, respectively, and in 21% of noninvasive papillary bladder tumors. HER2 gene amplification detection results using CISH and FISH showed a concordance of 100%. The occurrence of aneusomy of chromosome 17 in association with HER2 gene amplification was investigated. CONCLUSIONS: Validation of the HER2 oncogene in bladder cancer may allow for the potential use of Herceptin(R) antibody therapy. Therefore, the appropriate treatment approach has to be based on reliable and standardized analysis. Our results indicate that CISH could provide an accurate and practical alternative to FISH for the clinical diagnosis of HER2 oncogene amplification in bladder cancer.

Four years experience with teleneuropathology.

Between 2002 and 2005, we made 343 intraoperative frozen section diagnoses with a telepathology system, which connected a neurosurgical department to our department of pathology. An expert neuropathologist performed at least one brief gross examination, and this was followed by a smear preparation and a frozen section slide for each case. Frozen section diagnosis lasted on average 26.1 min, calculated from the beginning of gross examination until the surgeon was given the diagnosis. The majority of cases (283 or 83%) were diagnosed in 15-40 min. The mean time needed for macroscopic examination was 3.0 min, time for staining 4.2 min, smear diagnosis took 5.4 min and time for histological diagnosis 10.7 min. Telemicroscopy of a smear slide took 11 times longer compared with light microscopy, and telemicroscopy of a frozen section slide took 16 times longer than with light microscopy. In 6% of cases, the telepathology software posed technical problems, which delayed the time of diagnosis, but not by more than 4 min. We were able to render a diagnosis in all cases (system reliability 100%). After eliminating sampling errors (i.e. cases with no diagnostic material in the frozen section slides and/or in smear preparations), the diagnostic accuracy for telepathology was 97.9%.

Angiogenic potential of ductal carcinoma in situ (DCIS) of human breast.

AIMS: Comedo carcinoma is generally regarded as the subtype of ductal carcinoma in situ (DCIS) most likely to progress to invasive carcinoma. Increased angiogenesis could be associated with an enhanced risk of progression and might therefore be a marker of poor prognosis, as can be demonstrated for invasive breast tumours. Therefore, the present study investigates the correlations between the expression of oncoproteins (HER2, HER1/EGFR), angiogenic growth factors (VEGF and PD-ECGF/TP) and microvessel density (MVD) in DCIS. METHODS AND RESULTS: Forty-six breast cancer specimens of DCIS were tested immunohistochemically for the expression of angiogenic factors and oncoproteins. Different vascular distribution patterns of DCIS were examined semiquantitatively. Our results showed a significantly inverse correlation between HER1/EGFR and comedo-type DCIS (P = 0.048), but HER1/EGFR expression seemed to be independent of HER2 overexpression. VEGF expression was significantly associated with endoglin expression (P = 0.031) and the cuffing phenomenon (P = 0.017). CONCLUSIONS: The significantly inverse correlation between HER1/EGFR and comedo-type DCIS and the observation that VEGF and the other angiogenic factors tested are independent of HER2 overexpression, suggest that progression of comedo-type DCIS and angiogenesis in breast carcinoma are not regulated via the HER1/EGFR or HER2 pathway.

[Pancreas transplant pathology: clinicopathologic and experimental findings]. / Pathologie der Pankreastransplantation: Klinisch-pathologische und experimentelle Befunde.

134 pancreas transplantations (113 simultaneous pancreas-kidney, 5 pancreas after kidney, 16 pancreas transplants alone) done in Rostock from VI/95 to III/04 were evaluated in respect to pancreas transplant lesions. Additionally, 36 pancreas specimen of Brown Norway rats experimentally transplanted into diabetic Lewis rats were examined. From 55 out of the 134 pancreas transplant patients, 122 partly repeated pancreas graft specimen examinations were carried out morphologically. The principal lesions in the human pancreas transplants were acute (enzymatic) necrotizing transplant pancreatitis (41 samples), acute (13) and chronic (14) transplant rejection specimen as well as primary or secondary graft thrombosis (12 probes). 23 probes were zero-hour biopsies and 2 showed normal tissue. From 69 out of the 118 pancreas transplant patients with an additional kidney graft, a total of 159 renal transplant probes were examined. They showed the following lesions: acute tubular damage or acute renal failure (23), acute (56) or chronic (22) kidney graft rejection, acute tubular cyclosporine or FK 506 toxicity (53), and histologically normal graft tissue (8 cases). As in other grafted organs, the changes occurring in the transplanted pancreas consist of varying lesions related and/or not related to pancreas transplant rejection. A concise classification and a reproduceable grading schedule are suggested for diagnostic, differential diagnostic, therapeutic, and prognostic purposes. Pancreatic rejection lesions can be classified according to a proposed Rostock '04 working classification of pancreas allograft rejection into three grades (I: mild, II: moderate, III: severe) both for acute and chronic pancreas rejection. There was no direct correlation of the findings in 21 patients with simultaneously studied pancreas and renal transplant biopsies. In contrast to renal grafts, pancreatic rejection signs were often superimposed by acute transplantation pancreatitis with or without secondary graft thrombosis, nonenzymatic necroses or infection. Experimental acute pancreas transplant rejection in rats showed quite similar findings to human grafts and was also graded into three different acute rejection stages.

One 10-core prostate biopsy is superior to two sets of sextant prostate biopsies.

OBJECTIVES: To compare the efficiency of different transrectal ultrasonography (TRUS)-guided prostate biopsy techniques for detecting prostate cancer. MATERIALS AND METHODS: In all, 81 prostates from radical prostatectomy were used and two consecutive sets of sextant biopsies and one 10-core biopsy taken in each specimen. The 10-core biopsy consisted of a sextant biopsy and four cores from the far lateral areas of the prostate. To simulate a transrectal biopsy procedure, all biopsies were taken under TRUS guidance. RESULTS: In the first set of sextant biopsies 44 prostate cancers (54%) were detected and in the second set 51 (63%). Combining both sets of sextant biopsies 57 (70%) of the carcinomas were detected. One set of 10-core biopsies detected 66 (82%) of all prostate cancers. Overall, with the 10-core biopsies 16% more prostate tumours were diagnosed than with two consecutive sets of sextant biopsies. To find the same number of prostate cancers as with the 10-core technique, 14% of patients undergoing sextant biopsy would require a second set and 11% at least a third set of biopsies. CONCLUSIONS: The 10-core prostate biopsy technique is superior to the commonly used sextant technique and could spare patients unnecessary repeated biopsy. Even after including a second set of sextant biopsies, the total detection rate with these 12 biopsies was inferior to the 10-core technique.

[Sentinel lymph node biopsy in breast cancer patients--results and experience after 500 sentinel lymph node biopsies]. / Die Sentinellymphknotenbiopsie beim Mammakarzinom. Ergebnisse und Erfahrungen nach 500 Sentinellymphknotenbiopsien.

INTRODUCTION: Sentinel lymph node biopsy (SLNB) is a widely used technique for axillary staging in breast cancer patients. The principle to evaluate the axillary status of a breast cancer patient with a less invasive surgery than axillary lymph node dissection (ALND) meets the new minimally invasive concept in breast cancer surgery. Some breast cancer centers proceed to SLNB without ALND in SLN-negative patients. PATIENTS AND METHODS: Between March 1998 and March 2002, 500 SLNBs were performed. After a learning period with SLNB and ALND in 75 patients with a sensitivity of 96.2% and a false-negative rate of 3.8%, SLNB alone without further ALND was performed in a group of patients. In addition, the feasibility of SLNBin patients with locally advanced breast cancer, in patients after neoadjuvant chemotherapy and in patients with multicentricity was evaluated. The combined method with blue dye and technetium-99m-labeled human albumin for identification of SLNs was applied. RESULTS: 500 SLNBs were performed. The identification rate was 86.2%. After exclusion of patients with neoadjuvant chemotherapy and patients with multicentricity, the identification rate was 94.5%. SLNs were positive in 41.3% of patients and negative in 58.7% of patients. DISCUSSION: SLNB is an excellent method for axillary stag-ing and an alternative for ALND in a certain group of breast cancer patients.

Prostate cancer detection with two sets of ten-core compared with two sets of sextant biopsies.

OBJECTIVES: To compare the cancer detection of two consecutive sets of prostate biopsies using either the sextant or the 10-core technique. METHODS: Ninety-one specimens after radical prostatectomy were used and consecutive sets of biopsies were performed ex vivo on each prostate after the operation. The sextant biopsies were taken paramedian and midlobular, three per side. For the 10-core biopsies, two cores per side from the lateral areas of the prostate were added. We developed a realistic simulation of a transrectal sonographic biopsy procedure. RESULTS: In the first set of sextant biopsies, 55 prostate cancers (60.4%) were found; in the second set, 13 additional tumors were detected. Two consecutive sets of sextant biopsies thus found 68 tumors (74.7%). Using one 10-core biopsy led to cancer detection in 71 of the prostates (78%). A second 10-core biopsy revealed 11 additional tumors, for a cumulative cancer detection rate of 90.1%. We found that 9 (9.9%) of all the cancers were not diagnosed by two consecutive sets of this extended biopsy protocol. Eight of these cancers (88.9%) were clinically significant as determined by a tumor volume larger than 0.5 cm(3). CONCLUSIONS: Although the 10-core protocol is far superior to the commonly used sextant protocol, a significant number of prostate cancers can still be found on a second similar set of prostate biopsies. Even after two consecutive sets of 10-core biopsies, approximately 10% of the prostate tumors remained undetected. Most of them were clinically significant.

Massive progression of diffuse hepatic lymphangiomatosis after liver resection and rapid deterioration after liver transplantation.

Hepatic involvement is an exceptional presentation of lymphangiomatosis. In this case report we describe a patient who underwent liver transplantation secondary to progressive hepatic involvement, which occurred 2 yr after partial hepatectomy. Within 1 yr after liver transplantation the disease condition deteriorated, with rapid progression of pre-existing skeletal lesions and development of pulmonary disease. We conclude that liver transplantation may be a treatment option for hepatic lymphangiomatosis. In the presence of pre-existing extrahepatic lesions, however, liver transplantation seems to be contraindicated.

Immunohistochemical assessment of an asymptomatic glucagonoma in a patient with hypergastrinemia and marked antral angiodysplasia.

A 58-year-old patient had been treated for recurrent gastritis. Numerous gastroscopies indicated hemorrhagic gastritis combined with increasingly severe anemia. The patient was admitted with a hemoglobin of 4.4 g/dL. Gastroscopy showed marked antral angiodysplasia. Serum samples for gastrin were taken and found to be elevated (170-250 U/mL). The search for a gastrin-producing tumor with abdominal ultrasound, computed tomography, octreotide scan, and secretin test was negative, but angiography detected a pancreas tumor with a 2-cm diameter. Partial pancreatectomy and partial gastrectomy were performed. Immunohistochemical examination of the tumor did not show a gastrinoma but did show glucagon-reactive tissue. Further tumors or elevated plasma hormone levels were not detected, and a multiple endocrine neoplasia type I syndrome could be excluded. We thus found antral angiodysplasia with hypergastrinemia leading to detection of a glucagonoma diagnosed by immunohistochemistry. After more than 4 years of follow-up, the patient is without any symptoms or signs of relapse or secondary hormone syndrome.

Co-expression of tenascin-C and vimentin in human breast cancer cells indicates phenotypic transdifferentiation during tumour progression: correlation with histopathological parameters, hormone receptors, and oncoproteins.

Loss of epithelial morphology and the acquisition of mesenchymal characteristics are typical for carcinoma cells in tumour progression. In human breast carcinomas, up-regulation of tenascin-C (TN-C) and vimentin (Vim) is frequently observed in cancer cells and correlates with increased malignancy. Thus, it is possible that TN-C is co-expressed with Vim, representing cancer cells that have undergone epithelial-mesenchymal transition (EMT). This study examined 128 breast carcinomas using immunohistochemical techniques to demonstrate that mammary cancer cells are a prominent source of both TN-C and Vim. Statistical analysis revealed a significant association between TN-C and Vim expression in cancer cells. TN-C expression also correlated positively with overexpression of c-erbB-2 oncoprotein and down-regulation of oestrogen receptors (ERs). Eleven human mammary cancer cell lines and two 'normal' cell lines were examined by western blotting and immunohistochemistry. Co-expression of TN-C and Vim was detected in the carcinosarcoma cell line HS 578T, SK-BR-3 (B), fibroblast-like MDA-MB-231 cells, and the myoepithelial cell line HBL 100. These findings suggest that TN-C and Vim, when co-expressed in mammary carcinoma cells, represent regulator genes likely to be involved in EMT during mammary carcinogenesis.

Clinical relevance of HPV 16/18 testing methods in cervical squamous cell carcinoma.

Three different in situ hybridization (ISH) methods were compared for their clinical relevance and suitability in detecting human papillomavirus (HPV) 16/18 in 55 cases of squamous cell carcinoma (SCC) of the uterine cervix. After the initial biopsy, surgery, and/or radiation therapy, patients were followed for 5 to 8 years. A biotinylated cDNA probe for HPV 16/18 was applied to serial sections in combination with conventional streptavidin-biotin-peroxidase ISH (a widely applied routine procedure), streptavidin-Nanogold-silver ISH, and tyramide-signal amplified (TSA) streptavidin-Nanogold-gold ISH. The TSA principle is also known as catalyzed reporter deposition and is, apart from in situ PCR, probably today's most sensitive technique for detecting papillomavirus infection by microscopic means. Nearly 65.5% of the cases showed specific HPV 16/18 detection with TSA ISH, whereas 43.6% were positive with streptavidin-Nanogold-silver-ISH, and only 40.0% with peroxidase-based ISH. Statistical analyses comparing early and advanced stages in both HPV-positive and -negative groups revealed a significantly better outcome for early disease patients; statistical significance was most pronounced with TSA ISH. In a subgroup of patients who had received radiation therapy without prior surgery (n = 35), those with advanced disease were significantly less likely to have HPV 16/18 infection than those with early disease. A significantly better overall survival was observed in those women with HPV 16/18-positive carcinomas who had undergone surgery before radiation therapy (seen with all three methods). We conclude that TSA, in addition to being the most sensitive HPV in situ method applied in this study, gave the most significant and clinically relevant statistical results.

Collagenous colitis: a practically orientated approach to diagnosis.

The condensed article reports the results of 40 women and 16 men with a mean age of 59 +/- 2.6 years diagnosed with collagenous colitis between 1980 and 1993 at the UCLA Medical Center. Diarrheal symptoms lasted from 3 months to 15 years and a total of 291 biopsies were obtained from four sites in the large intestine (rectum and sigmoid colon, n = 141; descending colon, n = 60; transverse colon, n = 46; cecum and ascending colon, n = 44). Fifty randomly selected specimens from 30 patients were independently investigated to test concordance of histopathologic interpretation. Thickness of collagen band, inflammatory cells, and epithelium were assessed by grading with H&E stained sections; measurement of the subepithelial collagen band on trichrome-stained sections was compared with the subjective grading. The results of the study appeal both to endoscopists and histologists: 1) If sigmoidoscopy is applied in the differential diagnosis of diarrhea, biopsies including the most proximal extent visualized, are mandatory. 2) Inflammatory changes parallel the collagen deposition. 3) Subjective sensitivity in the estimation of collagen thickness in H&E stained slides is low. 4) Collagenous colitis without increase of inflammatory cells and a special type of collagen deposition is doubtful.

Detection of human papillomavirus in cervical carcinoma: comparison of peroxidase, Nanogold, and catalyzed reporter deposition (CARD)-Nanogold in situ hybridization.

We compared three in situ hybridization (ISH) methods for their applicability and sensitivity in detecting human papillomavirus (HPV) in 61 cases (1 Grade 1, 18 Grade 2, 42 Grade 3) of routinely processed squamous cell cervical carcinoma. A commercially available biotinylated probe for HPV-16/18 was applied to serial sections and detected by conventional streptavidin-biotin-peroxidase ISH, streptavidin-Nanogold-silver ISH, and catalyzed reporter deposition (CARD)-Nanogold-gold ISH. The latter method involved signal amplification by peroxidase-catalyzed deposition of biotinylated tyramides at the hybridization sites, followed by detection of accumulated biotin by streptavidin-Nanogold made visible by autometallography. The HPV-16/18 detection rates for the three methods were 39.3, 44.3, and 65.6%, respectively. In all of the three ISH methods, a punctate staining pattern (single or multiple intranuclear spots of variable size), presumably indicating viral integration, was highly predominant among the positive cases. Two of the cases identified as positive by streptavidin-biotinperoxidase ISH were rated negative with streptavidin-Nanogold-silver ISH, whereas six cases that were clearly negative with streptavidin-biotinperoxidase ISH became positively stained with streptavidin-Nanogold ISH. All of these discordant cases were positive by the highly sensitive CARD-Nanogold-gold ISH. In addition, the high detection sensitivity of CARD-Nanogold-gold ISH was confirmed by its ability to detect single copies of HPV-16 in SiHa cells. In general, we found that the intense black reaction product from Nanogold autometallography gave superior contrast to that obtained with the peroxidase system. After tyramide signal amplification, the staining was so clearly visible that preparations could be readily screened under low magnification. Our findings precisely demonstrated the need for improved sensitivity in the in situ detection of HPV. The CARD-Nanogold-gold technology looks promising as a highly sensitive method for routine ISH in molecular pathology.

Peptidergic innervation of the human clitoris.

In the present study, the distributions of neuropeptides in the normal human clitoris and in a clitoris from an adrenogenital syndrome (AGS) was demonstrated by immunohistochemistry (IHC). Immunohistochemical screening detected a complex network of nerve fibers containing vasoactive intestinal polypeptide (VIP), peptide histidine methionine (PHM), neuropeptide tyrosine (neuropeptide Y), C-flanking peptide of neuropeptide Y (CPON), calcitonin gene-related peptide (CGRP) and substance P immunoreactivities. Special attention was given to the VIP-related peptide helospectin, that has been detected in neuronal elements in the clitoris. No visible differences between the localization and distribution of peptidergic nerve fibers of normal and hypertrophic clitoris from AGS have been observed. Co-localization studies showed the co-existence of VIP, PHM and partly helospectin and neuropeptide Y with CPON within nerve fibers in the cavernous tissue and substance P and CGRP co-expression in nerve fibers especially underneath and within the glans clitoris.

The natural course of hepatitis C virus infection 18 years after an epidemic outbreak of non-A, non-B hepatitis in a plasmapheresis centre.

BACKGROUND: The natural history of hepatitis C virus (HCV) infection is variable and factors determining the course of the illness are unclear. AIMS: To determine the natural course of HCV infection in a well characterised group of patients 18 years after an epidemic outbreak of non-A, non-B hepatitis at a plasmapheresis centre. METHODS: Between 1994 and 1996, 20 of 30 affected individuals were studied. HCV infection was confirmed using second and third generation ELISA test kits. HCV RNA was detected by a polymerase chain reaction (PCR) method and HCV genotyping was performed by analysing amplicons from the conserved 5'-non-translated region generated by nested PCR. Thirty two liver biopsies were carried out in 14 patients. RESULTS: HCV antibodies were detected in all subjects. Eighteen patients had abnormal liver enzymes and 17 were HCV RNA positive, all of whom were infected with genotype 1a. Ninety per cent of this cohort showed evidence of chronic HCV infection with 50% having progressive liver disease and 20% cirrhosis 18 years after acute onset of non-A, non-B hepatitis. Considerable variation in disease outcome occurred between individuals and no correlation with clinical features of the acute illness was found. CONCLUSIONS: Variability in the consequences of HCV infection in cases infected with the same virus suggests that host factors are important in determining disease outcome. The factors which determine differences in the natural history of the disease still remain to be elucidated.