Heikki Joensuu

University of Helsinki, Helsinki, Uusimaa, Finland

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Publications (533)3842.51 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Prolonged steroid hormone therapy increases the risk of breast cancer, especially the risk of lobular cancer, but the effect of the levonorgestrel-releasing intrauterine system (LNG-IUS) use is controversial. In this study we aimed to test the hypothesis that risk for lobular breast cancer is elevated among LNG-IUS users. We identified from the national Medical Reimbursement Registry of Finland the women aged 30-49 who had used LNG-IUS for the treatment or prevention of menorrhagia in 1994-2007, and from the Finnish Cancer Registry breast cancers diagnosed before the age of 55 and by the end of 2012. A total of 2015 women had breast cancer diagnosed in a cohort of 93 843 LNG-IUS users during follow-up consisting of 1 032 767 women-years. The LNG-IUS users had an increased risk for both ductal breast cancer [standardized incidence ratio (SIR) 1.20, 95% confidence interval (CI) 1.14-1.25] and for lobular breast cancer (SIR 1.33, 95% CI 1.20-1.46), as compared with the general female population. The highest risk was found in LNG-IUS users who purchased the device at least twice, whose SIR for lobular cancer was 1.73 (95% CI 1.37-2.15). The results imply that intrauterine administration of levonorgestrel is not only related to an excess risk of lobular breast cancer but also, in contrary to previous assumptions, to an excess risk of ductal breast cancer.
    Acta oncologica (Stockholm, Sweden) 08/2015; · 3.71 Impact Factor
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    ABSTRACT: The immune system plays a major role in cancer progression. In solid tumors, 5-40 % of the tumor mass consists of tumor-associated macrophages (TAMs) and there is usually a correlation between the number of TAMs and poor prognosis, depending on the tumor type. TAMs usually resemble M2 macrophages. Unlike M1-macrophages which have pro-inflammatory and anti-cancer functions, M2-macrophages are immunosuppressive, contribute to the matrix-remodeling, and hence favor tumor growth. The role of TAMs is not fully understood in breast cancer progression. Macrophage infiltration (CD68) and activation status (HLA-DRIIα, CD163) were evaluated in a large cohort of human primary breast tumors (562 tissue microarray samples), by immunohistochemistry and scored by automated image analysis algorithms. Survival between groups was compared using the Kaplan-Meier life-table method and a Cox multivariate proportional hazards model. Macrophage education by breast cancer cells was assessed by ex vivo differentiation of peripheral blood mononuclear cells (PBMCs) in the presence or absence of breast cancer cell conditioned media (MDA-MB231, MCF-7 or T47D cell lines) and M1 or M2 inducing cytokines (respectively IFN-γ, IL-4 and IL-10). Obtained macrophages were analyzed by flow cytometry (CD14, CD16, CD64, CD86, CD200R and CD163), ELISA (IL-6, IL-8, IL-10, monocyte colony stimulating factor M-CSF) and zymography (matrix metalloproteinase 9, MMP-9). Clinically, we found that high numbers of CD163 + M2-macrophages were strongly associated with fast proliferation, poor differentiation, estrogen receptor negativity and histological ductal type (p<0.001) in the studied cohort of human primary breast tumors. We demonstrated ex vivo that breast cancer cell-secreted factors modulate macrophage differentiation toward the M2 phenotype. Furthermore, the more aggressive mesenchymal-like cell line MDA-MB231, which secretes high levels of M-CSF, skews macrophages toward the more immunosuppressive M2c subtype. This study demonstrates that human breast cancer cells influence macrophage differentiation and that TAM differentiation status correlates with recurrence free survival, thus further emphasizing that TAMs can similarly affect therapy efficacy and patient outcome.
    Breast Cancer Research 08/2015; 17(1). DOI:10.1186/s13058-015-0621-0 · 5.33 Impact Factor
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    ABSTRACT: The likelihood of recurrence in patients with breast cancer who have HER2-positive tumors is relatively high, although trastuzumab is a remarkably effective drug in this setting. Signal transducer and activator of transcription 3 protein (STAT3), a transcription factor that is persistently tyrosine-705 phosphorylated (pSTAT3) in response to numerous oncogenic signaling pathways, activates downstream proliferative and anti-apoptotic pathways. We hypothesized that pSTAT3 expression in HER2-positive breast cancer will confer trastuzumab resistance. We integrated reverse phase protein array (RPPA) and gene expression data from patients with HER2-positive breast cancer treated with trastuzumab in the adjuvant setting. We show that a pSTAT3-associated gene signature (pSTAT3-GS) is able to predict pSTAT3 status in an independent dataset (TCGA; AUC = 0.77, P = 0.02). This suggests that STAT3 induces a characteristic set of gene expression changes in HER2-positive cancers. Tumors characterized as high pSTAT3-GS were associated with trastuzumab resistance (log rank P = 0.049). These results were confirmed using data from the prospective, randomized controlled FinHer study, where the effect was especially prominent in HER2-positive estrogen receptor (ER)-negative tumors (interaction test P = 0.02). Of interest, constitutively activated pSTAT3 tumors were associated with loss of PTEN, elevated IL6, and stromal reactivation. This study provides compelling evidence for a link between pSTAT3 and trastuzumab resistance in HER2-positive primary breast cancers. Our results suggest that it may be valuable to add agents targeting the STAT3 pathway to trastuzumab for treatment of HER2-positive breast cancer.
    BMC Medicine 08/2015; 13(1). DOI:10.1186/s12916-015-0416-2 · 7.28 Impact Factor
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    ABSTRACT: Gastrointestinal stromal tumor (GIST) has been considered radiation-resistant, and radiotherapy is recommended only for palliation of bone metastases in current treatment guidelines. No registered prospective trial has evaluated GIST responsiveness to radiotherapy. Patients with GIST progressing at intra-abdominal sites or the liver were entered to this prospective Phase II multicenter study (identifier NCT00515931). Metastases were treated with external beam radiotherapy using either conformal 3D planning or intensity modulated radiotherapy and conventional fractionation to a cumulative planning target volume dose of approximately 40Gy. Systemic therapy was maintained unaltered during the study. Of the 25 patients entered, 19 were on concomitant tyrosine kinase inhibitor therapy, most often imatinib. Two (8%) patients achieved partial remission, 20 (80%) had stable target lesion size for ⩾3months after radiotherapy with a median duration of stabilization of 16months, and 3 (12%) progressed. The median time to radiotherapy target lesion progression was 4-fold longer than the median time to GIST progression at any site (16 versus 4months). Radiotherapy was generally well tolerated. Responses to radiotherapy were infrequent, but most patients had durable stabilization of the target lesions. GIST patients with soft tissue metastases benefit frequently from radiotherapy. Copyright © 2015 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.
    Radiotherapy and Oncology 07/2015; DOI:10.1016/j.radonc.2015.07.025 · 4.86 Impact Factor
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    Sebastian Bauer · Heikki Joensuu
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    ABSTRACT: Imatinib is strongly positioned as the recommended first-line agent for most patients with advanced gastrointestinal stromal tumor (GIST) due to its good efficacy and tolerability. Imatinib-resistant advanced GIST continues to pose a therapeutic challenge, likely due to the frequent presence of multiple mutations that confer drug resistance. Sunitinib and regorafenib are approved as second- and third-line agents, respectively, for patients whose GIST does not respond to imatinib or who do not tolerate imatinib, and their use is supported by large randomized trials. ATP-mimetic tyrosine kinase inhibitors provide clinical benefit even in heavily pretreated GIST suggesting that oncogenic dependency on KIT frequently persists. Several potentially useful tyrosine kinase inhibitors with distinct inhibitory profiles against both KIT ATP-binding domain and activation loop mutations have not yet been fully evaluated. Agents that have been found promising in preclinical models and early clinical trials include small molecule KIT and PDGFRA mutation-specific inhibitors, heat shock protein inhibitors, histone deacetylase inhibitors, allosteric KIT inhibitors, KIT and PDGFRA signaling pathway inhibitors, and immunological approaches including antibody-drug conjugates. Concomitant or sequential administration of tyrosine kinase inhibitors with KIT signaling pathway inhibitors require further evaluation, as well as rotation of tyrosine kinase inhibitors as a means to suppress drug-resistant cell clones.
    Drugs 07/2015; DOI:10.1007/s40265-015-0440-8 · 4.13 Impact Factor
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    ABSTRACT: Hepsin belongs to a family of cell-surface serine proteases, which have sparked interest as therapeutic targets because of the accessibility of extracellular protease domain for inhibitors. Hepsin is frequently amplified and/or overexpressed in epithelial cancers, but it is not clear how enhanced hepsin expression confers a potential for oncogenicity. We show that hepsin is consistently overexpressed in more than 40% of examined breast cancers, including all major biological subtypes. The effects of doxycycline-induced hepsin overexpression were examined in mammary epithelial organoids, and we found that induced hepsin acutely downmodulates its cognate inhibitor, hepatocyte growth factor (HGF) activator inhibitor type 1 (HAI-1). Hepsin-induced depletion of cellular HAI-1 led to a sharp increase in pericellular serine protease activity. The derepressed hepsin proteolytically activated downstream serine proteases, augmented HGF/MET signalling and caused deterioration of desmosomes and hemidesmosomes; structures important for cell cohesion and cell-basement membrane interaction. Moreover, chronic induction of hepsin considerably shortened the latency of Myc-dependent tumourigenesis in the mouse mammary gland. The serine protease and uPA system inhibitor WX-UK1, identified as a micromolar range hepsin inhibitor, prevented hepsin from augmenting HGF/MET signalling and disrupting desmosomes and hemidesmosomes. The findings suggest that the oncogenic activity of hepsin arises not only from elevated expression level but also from depletion of HAI-1, events which together trigger gain-of-function activity impacting HGF/MET signalling and epithelial cohesion. Thus, hepsin overexpression is a major oncogenic conferrer to a serine protease activity involved in breast cancer dissemination.Oncogene advance online publication, 13 July 2015; doi:10.1038/onc.2015.248.
    Oncogene 07/2015; DOI:10.1038/onc.2015.248 · 8.56 Impact Factor
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    ABSTRACT: We compared efficacy of trastuzumab versus no trastuzumab in patients with small (≤ 2 cm) human epidermal growth factor receptor 2 (HER2) -positive breast cancer treated in randomized trials. A meta-analysis was conducted using data from five of the six adjuvant trastuzumab trials. Efficacy end points were disease-free survival (DFS) and overall survival (OS). Separate analyses were prospectively planned for hormone receptor (HR) -positive and HR-negative cohorts. Random effect models and Yusuf-Peto fixed effects models assessed the impact of heterogeneity on baseline hazards and treatment effects across studies. Peto-Pike cumulative incidence estimates were stratified by study and nodal status. Median follow-up time was 8 years. For 2,263 patients with HR-positive disease, 8-year cumulative incidence rates comparing trastuzumab versus no trastuzumab were 17.3% versus 24.3% (P < .001) for DFS and 7.8% versus 11.6% (P = .005) for OS, respectively; for 1,092 HR-positive patients with zero or one positive lymph nodes, results were 12.7% versus 19.4% (P = .005) for DFS and 5.3% versus 7.4% (P = .12) for OS, respectively. For 1,957 patients with HR-negative disease, 8-year cumulative incidence rates were 24.0% versus 33.4% (P < .001) for DFS and 12.4% versus 21.2% (P < .001) for OS, respectively; for 1,040 HR-negative patients with zero or one positive lymph nodes, results were 20.4% versus 26.3% (P = .05) for DFS and 8.2% versus 12.2% (P = .084) for OS, respectively. Women with HER2-positive tumors ≤ 2 cm in the randomized trastuzumab trials derived substantial DFS and OS benefit from adjuvant trastuzumab. Trastuzumab-treated patients with HR-positive disease and ≤ one positive lymph node may be candidates for trials assessing less aggressive treatment approaches. © 2015 by American Society of Clinical Oncology.
    Journal of Clinical Oncology 06/2015; DOI:10.1200/JCO.2015.60.8620 · 18.43 Impact Factor
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    ABSTRACT: After the revelation of kinase targeting with orally available small molecules, the use of imatinib in chronic myelogenous leukemia and in gastrointestinal stromal tumor (GIST) has now become commonplace and just two of many examples of the use of kinase inhibitors in cancer. In this article, we discuss important practice points that may impact upon questions of therapy of primary and metastatic GIST, with the hope that the questions addressed in this rare solid tumor can serve as examples of what can be achieved with kinase-directed therapies in other cancers. We present cases that highlight some of the key issues in GIST management and afterward discuss both points of consensus and controversial issues in what is now recognized as one of the most common forms of sarcoma. ©AlphaMed Press.
    The Oncologist 06/2015; 20(7). DOI:10.1634/theoncologist.2014-0471 · 4.54 Impact Factor
  • Annals of Oncology 06/2015; 26(suppl 4):iv114-iv114. DOI:10.1093/annonc/mdv235.15 · 6.58 Impact Factor
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    ABSTRACT: Patients with gastrointestinal stromal tumour (GIST) are often followed up after surgery with longitudinally repeated imaging examinations to detect recurrence early. Studies on follow-up of GIST patients are few, the optimal follow-up methods are unknown and the recommendations for follow-up vary in guidelines. We reviewed the current evidence for follow-up of patients treated with surgery alone and of patients who were treated with adjuvant or neoadjuvant imatinib. Imaging of the abdomen and the pelvis with computerised tomography (CT) or magnetic resonance imaging (MRI) usually suffices, since metastases are uncommon at other sites. The frequency of imaging may be adjusted with the risk of recurrence with time. Very low risk GISTs are very frequently cured with surgery and usually require no regular follow-up after complete surgery, and annual CT of the abdomen and the pelvis for 5years suffices for most patients with a low to intermediate risk for recurrence. Most high-risk patients are treated with imatinib for at least 3years after surgery. CT or MRI may be carried out 6-monthly during adjuvant imatinib, 3 to 4-monthly during the 2years that follow discontinuation of imatinib when the risk of recurrence is high, and then at 6-12month intervals to complete 10years of follow-up. Recurrence after the first 10years of follow-up is infrequent. The follow-up schedules are best tailored with the risk of recurrence. The risk of recurrence should be estimated with the prognostic tools that consider the most relevant prognostic factors. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
    European journal of cancer (Oxford, England: 1990) 05/2015; 6(12). DOI:10.1016/j.ejca.2015.05.009 · 4.82 Impact Factor
  • Cancer Research 05/2015; 75(9 Supplement):P5-02-01-P5-02-01. DOI:10.1158/1538-7445.SABCS14-P5-02-01 · 9.28 Impact Factor
  • Annals of Oncology 05/2015; 26(suppl 3):iii15-iii15. DOI:10.1093/annonc/mdv117.01 · 6.58 Impact Factor
  • Cancer Research 05/2015; 75(9 Supplement):P5-19-07-P5-19-07. DOI:10.1158/1538-7445.SABCS14-P5-19-07 · 9.28 Impact Factor
  • Cancer Research 05/2015; 75(9 Supplement):P3-06-03-P3-06-03. DOI:10.1158/1538-7445.SABCS14-P3-06-03 · 9.28 Impact Factor
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    ABSTRACT: Metastatic gastrointestinal stromal tumour (GIST) is generally an incurable disease with variable response to imatinib. We aimed to develop prognostic nomograms to predict overall survival (OS) and progression-free survival (PFS) for patients treated with imatinib. Nomograms were developed in a training cohort (n=330) of patients treated in a randomised trial (EORTC-ISG-AGITG 62005 phase III study) using Cox regression models, and validated in patients (n=236) treated in routine clinical care from six referral centres. Nomogram performance was assessed by calculating the c statistic. A classification based on the nomograms' scores was generated to group patients according to risk. Nomogram risk factors for OS and PFS were size of the largest metastasis, tumour genotype, primary tumour mitotic count, haemoglobin and blood neutrophil count at commencement of imatinib. The nomograms predicted survival with a c statistic of 0.75 (training) and 0.62 (validation) for OS, and 0.69 (training) and 0.62 (validation) for PFS. When tested in the validation cohort, the nomograms discriminated well the high and intermediate risk from low risk patients (hazard ratio [HR] for OS 3.83, 95% confidence interval [CI] 1.71-8.56; and 2.48, 95% CI 1.12-5.50; for PFS 2.84, 95% CI 1.66-4.87; and 1.45, 95% CI 0.87-2.41, respectively). The nomograms predicted the risk of GIST progression and death with good discrimination of risk groups, and may be of value for patient counselling and risk stratification. Copyright © 2015 Elsevier Ltd. All rights reserved.
    European journal of cancer (Oxford, England: 1990) 03/2015; 51(7). DOI:10.1016/j.ejca.2015.02.015 · 4.82 Impact Factor
  • American Journal Of Pathology 02/2015; 185(4). DOI:10.1016/j.ajpath.2014.12.018 · 4.60 Impact Factor
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    ABSTRACT: Mutated KIT and platelet-derived growth factor alpha gene (PDGFRA) drive GI stromal tumor (GIST) oncogenesis, but the clinical significance of their single mutations is known incompletely. We identified 11 population-based series of patients with GIST through a literature search and pooled individual data from 3,067 patients treated with macroscopically complete tumor excision. Mutation analysis was done from 1,505 tumors. We analyzed associations between KIT and PDGFRA mutations and recurrence-free survival (RFS) in the subsets in which patients were treated with surgery alone. We identified 301 different single mutations in KIT and 33 in PDGFRA. Patients with PDGFRA mutations had more favorable RFS than those with KIT mutations (hazard ratio, 0.34; P = .004). Only one of the 35 GISTs with KIT exon 11 duplication mutations recurred. Patients with deletions of only one codon of KIT exon 11 had better RFS than those with another deletion type, and some KIT exon 11 substitution mutations (Trp557Arg, Val559Ala, and Leu576Pro) were also associated with favorable RFS. Patients with an identical mutation had greatly variable outcomes depending on the standard prognostic factors, notably, mitotic count. Commonly used risk stratification schemes tended to overestimate the risk for recurrence in subgroups with prognostically favorable mutations. GISTs with an identical KIT or PDGFRA mutation may have widely varying risks for recurrence. Most of the patients with PDGFRA mutations and those with KIT exon 11 duplication mutation or deletion of one codon have favorable RFS with surgery alone and are usually not candidates for adjuvant therapy. © 2015 by American Society of Clinical Oncology.
    Journal of Clinical Oncology 01/2015; 33(6). DOI:10.1200/JCO.2014.57.4970 · 18.43 Impact Factor
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    ABSTRACT: Most breast cancers are hormone receptor positive and exhibit a slow growth pattern. Based on biological properties, breast cancers are divided into four different biological subtypes. Furthermore, these subtypes are indicative of the risk of recurrence, which is also influenced by the size of the tumor and extension to lymph nodes. Postoperative adjuvant drug therapy is chosen on the basis of the biological type. Chemotherapy can be used in all subtypes. Hormonal therapies are used exclusively for the treatment of hormone receptor positive breast cancer. Trastuzumab antibody belongs to the treatment of the HER2 positive subtype.
    Duodecim; lääketieteellinen aikakauskirja 01/2015; 131(1):23-8.
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    ABSTRACT: Background: Abdominal radiotherapy for testicular cancer (TC) increases risk for second stomach cancer, although data on the radiation dose-response relationship are sparse. Methods: In a cohort of 22 269 5-year TC survivors diagnosed during 1959-1987, doses to stomach subsites were estimated for 92 patients who developed stomach cancer and 180 matched controls. Chemotherapy details were recorded. Odds ratios (ORs) were estimated using logistic regression. Results: Cumulative incidence of second primary stomach cancer was 1.45% at 30 years after TC diagnosis. The TC survivors who received radiotherapy (87 (95%) cases, 151 (84%) controls) had a 5.9-fold (95% confidence interval (CI) 1.7-20.7) increased risk of stomach cancer. Risk increased with increasing stomach dose (P-trend <0.001), with an OR of 20.5 (3.7-114.3) for >= 50.0 Gy compared with <10 Gy. Radiation-related risks remained elevated >= 20 years after exposure (P<0.001). Risk after any chemotherapy was not elevated (OR = 1.1; 95% CI 0.5-2.5; 14 cases and 23 controls). Conclusions: Radiotherapy for TC involving parts of the stomach increased gastric cancer risk for several decades, with the highest risks after stomach doses of >= 30 Gy. Clinicians should be aware of these excesses when previously irradiated TC survivors present with gastrointestinal symptoms and when any radiotherapy is considered in newly diagnosed TC patients.
    British Journal of Cancer 11/2014; 112(1):44-51. DOI:10.1038/bjc.2014.552 · 4.82 Impact Factor
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    ABSTRACT: Pregnancy, parity and circulating steroid hormone levels are associated with risk of breast cancer, but little is known about hormone concentrations during pregnancy and subsequent breast cancer risk. We evaluated early pregnancy (<140 days gestation) serum estradiol, estrone, progesterone, and testosterone and breast cancer risk in a nested case-control study in the Finnish Maternity Cohort. The cohort includes 98% of pregnancies registered in Finland since 1983. Individuals with samples collected in the first pregnancy leading to a live birth were eligible. Breast cancer cases (n=1,199) were identified through linkage with the Finnish Cancer Registry; 2,281 matched controls were selected using incidence density sampling. Odds ratios were calculated using conditional logistic regression. Hormone concentrations were not associated with breast cancer overall. Estradiol was positively associated with risk of breast cancer diagnosed age <40 (4th vs. 1st quartile OR 1.60 (1.07-2.39); ptrend=0.01), and inversely associated with breast cancer diagnosed at age ≥40 (4th vs. 1st quartile OR 0.71 (0.51-1.00); ptrend=0.02). Elevated concentrations of the steroid hormones were associated with increased risk of estrogen receptor (ER) and progesterone receptor (PR) negative tumors in women age <40 at diagnosis. We observed no association between steroid hormones and ER+/PR+ disease. These data suggest a positive association between high concentrations of early pregnancy steroid hormones and risk of ER-/PR- breast cancer in women diagnosed age <40, and an inverse association for overall breast cancer diagnosed age ≥40. Further research on pregnancy hormones and risk of steroid receptor negative cancers is needed to further characterize this association.
    Cancer Research 10/2014; 74(23). DOI:10.1158/0008-5472.CAN-14-2150 · 9.28 Impact Factor

Publication Stats

25k Citations
3,842.51 Total Impact Points


  • 1997–2015
    • University of Helsinki
      • • Department of Oncology
      • • Molecular/Cancer Biology Laboratory
      • • Department of Dental Public Health
      Helsinki, Uusimaa, Finland
  • 1995–2015
    • Helsinki University Central Hospital
      • Department of Oncology
      Helsinki, Uusimaa, Finland
    • Oulu University Hospital
      Uleoborg, Northern Ostrobothnia, Finland
  • 2007
    • The Princess Margaret Hospital
      Toronto, Ontario, Canada
  • 1995–2003
    • Uppsala University
      Uppsala, Uppsala, Sweden
  • 2002
    • Weill Cornell Medical College
      New York, New York, United States
  • 2000
    • Tampere University Hospital (TAUH)
      Tammerfors, Province of Western Finland, Finland
  • 1999
    • University of Oulu
      • Department of Medical Biochemistry and Molecular Biology
      Uleoborg, Oulu, Finland
  • 1988–1998
    • University of Turku
      • • MediCity Research Laboratory
      • • Department of Oncology and Radiotherapy
      • • Department of Pathology
      Turku, Province of Western Finland, Finland
  • 1986–1995
    • Turku University Hospital
      • Department of Obstetrics and Gynecology
      Turku, Province of Western Finland, Finland
  • 1994
    • National Public Health Institute
      Helsinki, Southern Finland Province, Finland
    • Turku PET Centre
      Turku, Province of Western Finland, Finland
  • 1992–1994
    • Kuopio University Hospital
      • Radiotherapy Unit
      Kuopio, Northern Savo, Finland
  • 1993
    • Finnish Cancer Registry, Helsinki
      Helsinki, Southern Finland Province, Finland