Upper gastrointestinal endoscopy procedure volume trends, perioperative mortality, and malpractice claims: Population-based analysis.

Background and study aims Upper gastrointestinal endoscopy (EGD) is one of the most common diagnostic procedures done to examine the foregut, but it can also be used for therapeutic interventions. The main objectives of this study were to investigate trends in EGD utilization and mortality related to it in a national low-threshold healthcare system, assess perioperative safety, and identify and describe patient-reported malpractice claims from the national database. Patients and methods We retrospectively identified patients from the Finnish Patient Care Registry who underwent diagnostic or procedural EGD between 2010 and 2018. In addition, patient-reported claims for malpractice were analyzed from the National Patient Insurance Center (PIC) database. Patient survival data were gathered collectively from the National Death Registry from Statistics Finland. Results During the study period, 409,153 EGDs were performed in Finland for 298,082 patients, with an annual rate of 9.30 procedures per 1,000 inhabitants, with an annual increase of 2.6%. Thirty-day all-cause mortality was 1.70% and 90-day mortality was 3.84%. For every 1,000 patients treated, 0.23 malpractice claims were filed. Conclusions The annual rate of EGD increased by 2.6% during the study, while the rate of interventional procedures remained constant. Also, while the 30-day mortality rate declined over the study period, it is an unsuitable quality metric for EGDs in comprehensive centers because a patient's underlying disease plays a larger role than the procedure in perioperative mortality. Finally, there were few malpractice claims, with self-evident causes prevailing.

Malpractice claims after antireflux surgery and paraesophageal hernia repair: a population-based analysis.

BACKGROUND: The complication rate of modern antireflux surgery or paraesophageal hernia repair is unknown, and previous estimates have been extrapolated from institutional cohorts. METHODS: A population-based retrospective cohort study of patient injury cases involving antireflux surgery and paraesophageal hernia repair from the Finnish National Patient Injury Centre (PIC) register between Jan 2010 and Dec 2020. Additionally, the baseline data of all the patients who underwent antireflux and paraesophageal hernia operations between Jan 2010 and Dec 2018 were collected from the Finnish national care register. RESULTS: During the study period, 5734 operations were performed, and the mean age of the patients was 54.9 ± 14.7 years, with 59.3% (n = 3402) being women. Out of all operations, 341 (5.9%) were revision antireflux or paraesophageal hernia repair procedures. Antireflux surgery was the primary operation for 79.9% (n = 4384) of patients, and paraesophageal hernia repair was the primary operation for 20.1% (n = 1101) of patients. A total of 92.5% (5302) of all the operations were laparoscopic. From 2010 to 2020, 60 patient injury claims were identified, with half (50.0%) of the claims being related to paraesophageal hernia repair. One of the claims was made due to an injury that resulted in a patient's death (1.7%). The mean Comprehensive Complication Index scores were 35.9 (± 20.7) and 47.6 (± 20.8) (p = 0.033) for antireflux surgery and paraesophageal hernia repair, respectively. Eleven (18.3%) of the claims pertained to redo surgery. CONCLUSIONS: The rate of antireflux surgery has diminished and the rate of paraesophageal hernia repair has risen in Finland during the era of minimally invasive surgery. Claims to the PIC remain rare, but claims regarding paraesophageal hernia repairs and redo surgery are overrepresented. Additionally, paraesophageal hernia repair is associated with more serious complications.

Patients with fibromyalgia in Finnish healthcare center - one-year follow up.

OBJECTIVES: The study aimed to find whether Örebro Musculoskeletal Pain Screening Questionnaire (ÖMPSQ) predicts the severity of fibromyalgia symptoms after one year in patients with fibromyalgia. The second aim of the study was to observe how symptoms evolved during a one-year follow-up. DESIGN: Prospective cohort and observational study. Five questionnaires were sent to patients. The same questionnaires (excluding ÖMPSQ) were sent after one year. The patients were allocated into two cohorts using the results of ÖMPSQ. Other variables were analyzed and observed separately. SETTING: Primary healthcare center in the city of Nokia, Pirkanmaa, Finland. SUBJECTS: Patients with fibromyalgia were included in the study after a physician's examination and confirmation of diagnosis with the assistance of the American College of Rheumatology (ACR) 2010 criteria. MAIN OUTCOME MEASURES: Fibromyalgia impact questionnaire (FIQ) scores. RESULTS: The FIQ scores increased slightly in both ÖMPSQ-cohorts with no statistically significant differences. The patients mostly reported that the symptoms were unchanged or got worse when asked separately from other questionnaires. There was a statistically significant decrease in PHQ-9 score in depressed patients who received antidepressants and/or psychological therapy. In addition, FIQ scores also decreased in depressed patients. Patients who received alterations to the treatment plan reported positive changes in the symptoms more often. CONCLUSION: With these results, we cannot conclude that ÖMPSQ predicts the patient's severity of symptoms. On the contrary, we can conclude that antidepressants and/or psychological therapy might reduce fibromyalgia symptoms for depressed patients with fibromyalgia. Patients with fibromyalgia might benefit from clinical evaluation and modifications to the treatment plan if necessary.

The long-term prognosis is not well known, and there are limited tools to predict the development of symptoms.ÖMPSQ does not seem to be useful for predicting the development of fibromyalgia in patients who already have been diagnosed with fibromyalgia.Management of depression for patients with fibromyalgia might be effective in reducing fibromyalgia symptoms.Patients with fibromyalgia in Finnish healthcare center ­ one-year follow-up.

Ultrasound-guided closure of the femoral artery during venoarterial decannulation using a large-bore closure device.

BACKGROUND: Peripheral femoro-femoral venoarterial extracorporeal membrane oxygenation (VA-ECMO) is viable for fast hemodynamic assistance during cardiogenic shock. Ultrasound-guided closure with a large-bore device (MANTA®) is a feasible option potentially replacing surgical arteriotomy closure in peripheral VA-ECMO decannulation. METHODS: This retrospective study included patients weaning from percutaneously inserted femoro-femoral VA-ECMO at the Helsinki University Hospital, Finland in 2012-2020. The primary endpoints were access-site complications, a composite of hematomas/seromas/surgical site infections (SSIs), and the safety endpoint of vascular complications (VCs). RESULTS: A total of 100 consecutive percutaneously implanted and weaned VA-ECMO patients were stratified into two groups by decannulation strategy: percutaneous ultrasound-guided MANTA device (n = 21, 21.0%) or surgical approach (n = 79, 79.0%). The mean age of the cohort was 51 ± 13 years and females represented 25.0%. The technical success rate of the percutaneous ultrasound-guided MANTA technique was 95.2%. In multivariate analysis, surgical closure was associated with a higher incidence of combined access site hematomas/seromas/SSIs compared to percutaneous ultrasound-guided deployment of MANTA device (44.3% versus 9.5%, odds ratio (OR): 7.162, 95% confidence interval (CI): 1.544-33.222; p = 0.012). Similarly, access-site complications necessitating interventions were more frequent in the surgical closure group compared to US-MANTA (ultrasound-guided MANTA) group (26.6% versus 0.0%, p = 0.005). VCs were infrequent in both groups without any significant intergroup difference (p > 0.99). CONCLUSIONS: Percutaneous ultrasound-guided MANTA closure of the femoral artery after VA-ECMO decannulation was associated with high technical success rate and low incidence of VCs. Compared to surgical closure, access-site complications were significantly less frequent, along with access-site complications necessitating interventions.

Paraconduit hernia after minimally invasive esophagectomy - incidence and risk factors.

BACKGROUND: Paraconduit hernia is a relatively common long-term complication after esophagectomy which has the potential to cause great morbidity and even mortality. The aim of this study is to examine the risk factors and incidence of paraconduit hernia after minimally invasive esophagectomy (MIE) in esophageal adenocarcinoma patients who have received neoadjuvant treatment. METHODS: Minimally invasive esophagectomies done for patients with neoadjuvant-treated esophageal or esophagogastric junction adenocarcinoma at our institution between 2008 and 2018 were included in this study. All patients with symptomatic or incidentally found paraconduit hernias on computed tomography scans were identified. Patient demographics were analyzed using logistic and Cox regression. RESULTS: The incidence of paraconduit hernia was 14 out of 171 patients (8.2%). The hernia was surgically repaired in 10 (71.4%) of patients. Laparoscopic approach was used in 90% of the repairs, with one (11.1%) conversion to laparotomy. Emergency operations accounted for three (30%) of the operations. The complication rate was 10% (n = 1) and 90-day mortality was 10% (n = 1). Neither sarcopenia nor muscle mass loss was not associated with paraconduit hernia development, whereas preoperative radiotherapy (OR = 8.57, CI = 1.98-33.8, p = .002) was a strong risk factor for paraconduit hernia. Higher BMI had a protective effect (OR = 0.83 per point, 95% CI = 0.69-0.97, p = .027). CONCLUSIONS: Paraconduit hernia is a relatively common complication after MIE for neoadjuvant-treated adenocarcinoma patients. Preoperative radiotherapy was associated with a higher risk of paraconduit hernia. Minimally invasive repair of paraconduit hernia after esophagectomy is efficient and has a low complication rate both in elective and emergency cases.

General thoracic surgery in Finland, a perspective from the Helsinki University Hospital.

The field of thoracic surgery is a rapidly developing field due to exciting developments in technology and oncologic treatments as well as continuous innovation in surgical technique. Although the population of Finland is relatively small, general thoracic surgery is represented at a high level in five centralized university centers, Helsinki University Hospital, Tampere University Hospital, Turku University Hospital, Kuopio University Hospital and Oulu University Hospital. Thus, high case volume and good results are achieved in these centers. Here, we describe a short history, current state and future prospects of the field of cardiothoracic surgery in Finland, with a focus on general thoracic surgery and the perspective of Helsinki University Hospital. From the field's birth in Finland, marked by the first lobectomy, in the late 1930's, it has grown and adapted more and more modern techniques such as totally minimally invasive esophagectomy and robotic lung cancer surgery. Nowadays, most of general thoracic surgery in Helsinki University Hospital is either minimally invasive or robotic and open surgery is the exception to the norm. Helsinki University Hospital has a strong presence in the European general thoracic surgery community and aims to do so in the future by investing on training & education, research and surgical innovation.

Congenital diaphragmatic hernia in adults: a decade of experience from a single tertiary center.

INTRODUCTION: Congenital diaphragmatic hernias (CDHs) in adults remain rare, with limited data on them available. However, CDHs can cause respiratory and gastrointestinal symptoms in adults, even resulting in the strangulation of the bowel when incarcerated. Here, we aimed to analyze surgical outcomes among adult patients. The primary outcome of interest was the complication rate, reoperations and 90-day mortality after laparoscopic and open hernia repair. METHODS: We identified all adult patients diagnosed with a Morgagni or Bochdalek hernia treated operatively between 2010 and 2019 in a single tertiary care hospital. Data on patient demographics, surgical characteristics, mortality and morbidity were collected. RESULTS: In total, we identified 37 patients (67.6% female; average age, 57 years). Overall, 78.4% patients underwent minimally invasive operations, while 35.1% underwent emergency operations. A Clavien-Dindo grade II-V complication was experienced by 18.9% of patients. No deaths occurred within 90 days of surgery, and we detected no recurrences in short-term or long-term follow-up. A minimally invasive technique correlated with a shorter hospital stay of 3.6 days versus 6.8 days in the open surgery group (p = .007, t = 3.3, 95% confidence interval = 1.04-5.21). CONCLUSION: Our findings indicate that the laparoscopic repair of a congenital diaphragmatic hernia is safe and effective, offering short hospital stay and a low amount of complications.

Hyperthermic Intrathoracic Chemoperfusion for Malignant Pleural Mesothelioma: Systematic Review and Meta-Analysis.

Malignant pleural mesothelioma (MPM) is an aggressive malignancy of the pleural lining with exceptionally poor survival. Hyperthermic intrathoracic chemoperfusion (HITHOC) is commonly used with surgery in limited disease. However, data on its effect on survival are limited. In this systematic review and meta-analysis, we analyzed a total of 11 observational articles. HITHOC was compared to control arm that did not receive HITHOC in three studies including 762 patients. The pooled analysis of these studies revealed an SMD of 0.24, with 95% CI of 0.06-0.41 favoring the HITHOC group, reaching statistical significance. The survival effect of HITHOC in epithelioid MPM vs. non-epithelioid MPM was analyzed in four studies. Pooled analysis showed an SMD of 0.79 (95% CI = 0.48-1.10) favoring epithelioid MPM. Based on available data, there seems to be a benefit with HITHOC in regards to overall survival in the treatment of all mesothelioma patients. Multicenter randomized controlled trials are needed to validate and standardize this treatment approach.

Hand-sewn versus stapled anastomoses for esophagectomy: We will probably never know which is better.

Objective: Esophagectomy remains the mainstay of treatment for nonmetastatic esophageal cancer. The optimal technique for anastomosis after esophagectomy remains unknown. The purpose of this systematic meta-analysis is to combine the available high-quality evidence to provide esophageal surgeons with an evidence base for their decision making. Methods: A systematic search of multiple databases was conducted to find randomized controlled trials of esophageal anastomotic techniques. A meta-analysis of the pooled data was conducted. Results: A total of 19 studies with 2123 patients were included in the meta-analysis. The pooled analysis revealed a 102% higher incidence of anastomotic leak after hand-sewn anastomosis compared with stapled anastomosis (odds ratio [OR], 2.02; 95% confidence interval [CI], 1.48-2.75). Anastomotic stricture rate was also 31% higher with hand-sewn anastomosis (OR, 1.31; 95% CI, 1.00-1.7). Thirty-day mortality did not show statistical difference favoring one anastomosis technique to another (OR, 0.68; 95% CI, 0.45-1.04). None of anastomotic leak rate, anastomotic stricture rate, or 30-day overall survival differed between anastomotic techniques in studies with only thoracic anastomoses. In cervical position hand-sewn anastomosis was associated with higher rate of anastomotic leak (OR, 2.02; 95% CI, 1.33-3.05) and stricture (OR, 1.77; 95% CI, 1.15-2.72), but no difference in 30-day mortality. Conclusions: This meta-analysis showed a signal of higher rate of leak and stricture in hand-sewn anastomoses, but sensitivity analyses did not show a consistent outcome, so these results should be interpreted with caution.

Health-related quality of life after laparoscopic repair of giant paraesophageal hernia: how does recurrence in CT scan compare to clinical success?

BACKGROUND: Computed tomography (CT) is widely used in the diagnosis of giant paraesophageal hernias (GPEH) but has not been utilised systematically for follow-up. We performed a cross-sectional observational study to assess mid-term outcomes of elective laparoscopic GPEH repair. The primary objective of the study was to evaluate the radiological hernia recurrence rate by CT and to determine its association with current symptoms and quality of life. METHODS: All non-emergent laparoscopic GPEH repairs between 2010 to 2015 were identified from hospital medical records. Each patient was offered non-contrast CT and sent questionnaires for disease-specific symptoms and health-related quality of life. RESULTS: The inclusion criteria were met by 165 patients (74% female, mean age 67 years). Total recurrence rate was 29.3%. Major recurrent hernia (> 5 cm) was revealed by CT in 4 patients (4.3%). Radiological findings did not correlate with symptom-related quality of life. Perioperative mortality occurred in 1 patient (0.6%). Complications were reported in 27 patients (16.4%). CONCLUSIONS: Successful laparoscopic repair of GPEH requires both expertise and experience. It appears to lead to effective symptom relief with high patient satisfaction. However, small radiological recurrences are common but do not affect postoperative symptom-related patient wellbeing.

Elevated Circulating Activin A Levels in Patients With Malignant Pleural Mesothelioma Are Related to Cancer Cachexia and Reduced Response to Platinum-based Chemotherapy.

BACKGROUND: Previous preclinical studies have shown that activin A is overexpressed in malignant pleural mesothelioma (MPM), associates with cancer cachexia, and is observed in in vitro resistance to platinum-based chemotherapy. We evaluated circulating activin levels and their endogenous antagonists' follistatin/follistatin-like 3 in intrathoracic tumors. MATERIALS AND METHODS: Patients suspected of thoracic malignancy were recruited prior to surgery. Serum samples were collected from 21 patients with MPM, 59 patients with non-small-cell lung cancer (NSCLC), and 22 patients with benign lung lesions. Circulating activin/follistatin levels were measured using enzyme-linked immunosorbent assay and compared with clinicopathologic parameters. RESULTS: Circulating activin A levels were elevated in patients with MPM when compared with patients with NSCLC or benign lung lesion samples (P < .0001). Also, follistatin and follistatin-like 3 levels were the highest in MPM, although with less difference compared with activin A. Receiver operating characteristic analysis for activin A for separating NSCLC from benign lung lesion showed an area under the curve of 0.856 (95% confidence interval, 0.77-0.94). Activin A levels were higher in patients with cachexia (P < .001). In patients with MPM, activin A levels correlated positively with computed tomography-based baseline tumor size (R = 0.549; P = .010) and the change in tumor size after chemotherapy (R = 0.743; P = .0006). Patients with partial response or stable disease had lower circulating activin A levels than the ones with progressive disease (P = .028). CONCLUSION: Activin A serum level could be used as a biomarker in differentiating malignant and benign lung tumors. Circulating activin A levels were elevated in MPM and associates with cancer cachexia and reduced chemotherapy response.

Low skeletal muscle mass in stented esophageal cancer predicts poor survival: A retrospective observational study.

BACKGROUND: In esophageal cancer, nutritional challenges are extremely common. Malignant obstruction resulting from esophageal cancer (EC) is often treated by the insertion of expandable stents, but little is known as to the role and evolution of sarcopenia in this patient population. The aim of this article was to determine the effects of body mass parameters on survival of advanced EC patients who received a stent for palliation of malignant obstruction. METHODS: This was a retrospective observational study of 238 EC patients who had a stent inserted for palliation of malignant obstruction between 2005 and 2013. Skeletal muscle mass was calculated from abdominal computed tomography scans, and the patients were divided into sarcopenic and non-sarcopenic groups. A follow-up computed tomography scan was available in 118 patients. The primary outcome was survival, and complication rates and the need for an alternative enteral feeding route were secondary outcomes. RESULTS: Sarcopenia occurred in 199 (85%) patients. Median survival was 146 (range: 76-226) days in the sarcopenia group and 152 (range: 71-249) days in the non-sarcopenic group (P = 0.61). Complication rates between the groups were not significantly different (P = 0.85). In Cox regression analysis, the skeletal muscle index was inversely correlated with overall survival (hazard ratio 0.98, 95% confidence interval 0.97-0.99; P = 0.033). CONCLUSIONS: Sarcopenia, defined by consensus thresholds, at the time of stent insertion cannot effectively predict poor survival in this patient cohort, but a lower skeletal muscle index correlates with poor prognosis as a continuous variable.

Surgically Treated Unsuspected N2-Positive NSCLC: Role of Extent and Location of Lymph Node Metastasis.

BACKGROUND: The role of surgery in the treatment of non-small-cell lung cancer that has spread to ipsilateral mediastinal or hilar lymph nodes (LNs) is controversial. We examined whether the location of LNs positive for non-small-cell lung cancer in mediastinum or hilum influences the survival of these patients. PATIENTS AND METHODS: We reviewed data from 881 patients and analyzed those with unsuspected N2 disease or hilar (station 10) LNs. The patients were stratified into the following groups: group A, positive hilar Naruke 10; group B, superior mediastinal and aortic nodes (Naruke 1, 2, 3, 4, 5, and 6); group C, inferior mediastinal nodes (Naruke 7, 8, and 9), and multilevel group D (2 or more positive N2 levels). RESULTS: A total of 69 pN2 and 19 pN1 patients were included. Progression-free survival (PFS) was statistically significant better in group B versus group C (P = .044) and group B versus group D (P = .0086). The overall survival (OS) of group A did not differ from that of group C. A statistically significant better OS was found between groups B and D (P = .051). CONCLUSION: Inferior positive mediastinal N2 node patients seem to have an OS and PFS as poor as multilevel N2 disease patients. The OS and PFS of patients with positive hilar disease are similar to those in the inferior mediastinal positive N2 group. Superior positive mediastinal N2 node patients have better OS and PFS than the inferior mediastinal positive N2 group.

Loss of skeletal muscle mass during neoadjuvant treatments correlates with worse prognosis in esophageal cancer: a retrospective cohort study.

BACKGROUND: Nutritional deficits, cachexia, and sarcopenia are extremely common in esophageal cancer. The aim of this article was to assess the effect of loss of skeletal muscle mass during neoadjuvant treatment on the prognosis of esophageal cancer patients. METHODS: Esophageal cancer patients (N = 115) undergoing neoadjuvant therapy and surgery between 2010 and 2014 were identified from our surgery database and retrospectively analyzed. Computed tomography imaging of the total cross-sectional muscle tissue measured at the third lumbar level defined the skeletal muscle index, which defined sarcopenia (SMI < 52.4 cm2/m2 for men and < 38.5 cm2/m2 for women). Images were collected before and after neoadjuvant treatments. RESULTS: Sarcopenia in preoperative imaging was prevalent in 92 patients (80%). Median overall survival was 900 days (interquartile range 334-1447) with no difference between sarcopenic (median = 900) and non-sarcopenic (median = 914) groups (p = 0.872). Complication rates did not differ (26.1% vs 32.6%, p = 0.725). A 2.98% decrease in skeletal muscle index during neoadjuvant treatment correlated with poor 2-year survival (log-rank p = 0.04). CONCLUSION: Loss of skeletal muscle tissue during neoadjuvant treatment correlates with worse overall survival.

Preoperative stenting in oesophageal cancer has no effect on survival: a propensity-matched case-control study.

OBJECTIVES: Previous studies have shown a link between oesophageal stenting before oesophagectomy and worse oncological outcomes. Our objective was to determine the effect of preoperative self-expanding covered metallic stent (SEMS) on survival, progression-free survival (PFS), operative time and complication rates in oesophageal cancer (EC). METHODS: This study included EC patients undergoing surgery between January 2006 and January 2014 with a cT2 tumour or higher ( n = 174; 135 adenocarcinomas and 39 squamous cell carcinomas). We propensity matched 1:1 a preoperative SEMS group ( n = 30) to a control group. Despite the propensity matching, statistically non-significant residual covariate imbalances persisted. Median follow-up time was 33 months (range: 0-118 months). We performed Kaplan-Meier survival analysis for OS and PFS, the Student's t -test for operative time and the chi-squared test for complication rates. RESULTS: Median survival in the SEMS group was 28.5 months (range: 0-116 months) vs 34 months (4-118 months) in the control group and median PFS was 22 months (0-111 months) vs 27 (4-113 months) ( P = 0.748 and P = 0.764, respectively). Mean operative times between groups were 436 min vs 375 min ( P = 0.017). No differences emerged in intraoperative (23.3% vs 10%, P = 0.299), early (50.0% vs 46.7%, P = 1) or late complication rates (53.3% vs 43.3%, P = 0.606). CONCLUSIONS: SEMS application has no significant effect on survival, PFS or complications. Mean operative time was significantly higher in the SEMS insertion group. We therefore conclude that preoperative SEMS insertion makes the operation more challenging by increasing operative time, but is otherwise a feasible and safe strategy in experienced centres as a bridge to surgery.

[Designer-drug overdose patients treated by Helsinki Emergency Medical Services in 2009-2012]. / Muuntohuumeita käyttäneet yliannostuspotilaat Helsingin ensihoidossa vuosina 2009-2012.

BACKGROUND: Designer drug abuse has increased during the last decade. MATERIAL AND METHODS: Retrospective study of designer drug overdoses in Helsinki emergency medical services (EMS) 2009-2012. Use of drugs was self-reported or from other people present. RESULTS: There were 98 patients (72% male), median age 30 years. The majority reported MDPV and polysubstance abuse. Only 15% were administered medication by EMS and 69 were transported. In the emergency department 53% required specific care, mostly benzodiazepines. Most (78%) were discharged within less than 24 hours. Infectious complications were the main reason for admission. CONCLUSIONS: Designer drug overdose patients require drug administration rarely on scene, but quite often in the emergency department, usually sedation. Admissions are rare.

Trichodysplasia spinulosa-associated polyomavirus (TSV) and Merkel cell polyomavirus: correlation between humoral and cellular immunity stronger with TSV.

Merkel Cell Polyomavirus (MCV) is a common infectious agent likely to be involved in the pathogenesis of most Merkel cell carcinomas (MCC). Trichodysplasia spinulosa-associated polyomavirus (TSV), which exhibit high seroprevalence in general population, has been detected in trichodysplasia spinulosa (TS) skin lesions suggesting an etiological role for this disease. Previous studies have shown strong MCV-specific T-cell responses, while no data exist on T-cell immunity against TSV. In order to characterize Th-cell immunity against TSV, and to allow comparisons with the MCV-specific Th-cell immunity, we studied TSV-specific proliferation, IFN-γ, IL-10 and IL-13, and MCV-specific IFN-γ and IL-10 responses in 51 healthy volunteers, and in one MCC patient. Recombinant TSV and MCV VP1 virus-like particles (VLPs) were used as antigens. A significant correlation was found between virus-specific Th-cell and antibody responses with TSV; with MCV it proved weaker. Despite significant homology in amino acid sequences, Th-cell crossreactivity was not evident between these viruses. Some subjects seronegative to both TSV and MCV exhibited Th-cell responses to both viruses. The agent initially priming these Th-cells remains an enigma. As CD8(+) cells specific to MCV T-Ag oncoprotein clearly provide an important defense against established MCC, the MCV VP1-specific Th-cells may, by suppressing MCV replication with antiviral cytokines such as IFN-γ, significantly contribute to preventing the full process of oncogenesis.