O Björk

Karolinska Institutet, Solna, Stockholm, Sweden

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Publications (54)145.1 Total impact

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    ABSTRACT: BACKGROUND: The present study aimed to investigate the relationship between school attendance and infection requiring antimicrobial treatment in children undergoing treatment for cancer. PROCEDURE: A national cohort of children aged 7-16 years undergoing cancer treatment was assessed during two observation periods of 19 days each, 1 month (n = 89) and 2.5 months (n = 89) poststart of treatment. Children free from infection at start of each observation period were included. Multivariable logistic regression analyses were performed including factors potentially associated with start of antimicrobial treatment. RESULTS: Twenty-seven (30%) children started antimicrobial treatment during the first observation period. Factors associated with an increased risk of starting antimicrobial treatment were diagnosed with sarcoma (OR = 24.37, P = 0.002) or non-Hodgkin lymphoma (OR = 17.57, P = 0.025), having neutropenia (OR = 5.92, P = 0.020) and age less than 13 years (OR = 8.54, P = 0.014). During the second observation period, when 20 (22%) children started antimicrobial treatment, the probability of starting treatment was increased in children with neutropenia (OR = 4.25, P = 0.007). There was no statistically significant association between starting treatment for infection and school attendance. CONCLUSIONS: In this study, children attending school while undergoing cancer treatment did not run a higher risk of starting antimicrobial treatment than children absent from school. However, there is a need for further studies evaluating risk of infections in children with ongoing cancer treatment. Pediatr Blood Cancer © 2013 Wiley Periodicals, Inc.
    Pediatric Blood & Cancer 08/2013; 60(8). DOI:10.1002/pbc.24510 · 2.56 Impact Factor
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    ABSTRACT: Sweden's population is gradually changing to become more multiethnic and diverse and that applies also for recipients of health care, including childhood cancer care. A holistic view on the sick child in the context of its family has always been a cornerstone in childhood cancer care in Sweden. The purpose of this study was to gain knowledge about the experiences and main concern of foreign-born parents in the context of paediatric cancer care. Interviews were performed with eleven foreign-born parents and data were analysed using a classic grounded theory approach. Foreign-born parents often feel in a position of powerless dependence, but family interests are protected in their approaches to interaction with healthcare staff, through cooperation, contesting, and reluctant resigning. Healthcare staff need to listen to foreign-born parents and deal with their concerns seriously to prevent powerless-dependence and work for trustful cooperation in the common fight against childhood cancer.
    International Journal of Pediatrics 03/2012; 2012:681301. DOI:10.1155/2012/681301
  • Anne Kästel, Karin Enskär, Olle Björk
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    ABSTRACT: The aim of the study is to highlight parents' views on information in childhood cancer care. A qualitative design, appropriate to gain a holistic view, has been chosen. Eight families with children diagnosed with cancer, of various ages and gender and from various backgrounds, participated in five interviews each during the first year of the child's illness. If the parents' needs were fulfilled, they were better equipped to handle the illness of their child, which is totally dependant on how the matter of information is dealt with. Information is a complex and demanding issue for the persons involved and the families' views were divergent in this area. Sometimes they seemed to obtain the information successfully and sometimes there were great problems in this respect. Therefore their preferences must be considered. There has to be an improvement from the aspects of what, when and how information is provided. The major findings of this study indicate that the families need better support and more distinct instructions to be able to cope with the situation.
    European journal of oncology nursing: the official journal of European Oncology Nursing Society 11/2010; 15(4):290-5. DOI:10.1016/j.ejon.2010.10.007 · 1.79 Impact Factor
  • S Hayder, O Björk, B Nilsson
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    ABSTRACT: A statistical analysis of possible risk factors for relapse during maintenance therapy (MT) for acute lymphoblastic leukemia (ALL) has been performed. The patient material consists of 64 patients. Twenty-six patients were classified as standard risk (SR), 21 as intermediate risk (IR), and 17 as high-risk (HR) patients. Seventeen patients relapsed and 50 patients (78%) are alive at a median observation period of 86 months (range 39-146 months). Mean white blood cell count (mean WBC) based on weekly determinations, duration of treatment interruption, and the number of infectious episodes were calculated in each patient during the first 6 months of MT. In analyses starting at 6 months after the beginning of MT, these factors were related to relapse risk, time to relapse, and time to infection. Using the median WBC value (3.9 x 10(9)/L) of all patients during the first 6 months as a cutoff point, 14 patients with levels higher, and 3 patients with levels lower relapsed (p = .0004). Adjustment of mean WBC for leukemia risk groups had no influence on the analysis. Time to relapse was related to duration of interruption of MT (p less than .01). Time to relapse was not related to leukemia risk groups. Infection frequency was higher in HR patients compared to SR and IR risk patients (p = .04). As WBC level had a prognostic value and was previously shown to be related to 6-mercaptopurine (6-MP) peak plasma concentration, monitoring 6-MP plasma levels during MT could be helpful for optimizing treatment.
    Pediatric Hematology and Oncology 07/2009; 9(1):21-7. DOI:10.3109/08880019209006392 · 0.96 Impact Factor
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    ABSTRACT: The aim of the study was to describe how young adults who have survived childhood cancer consider their present life to be influenced by the cancer experience. A cohort of 246 long-term survivors were approached a median of 16 years after diagnosis. Semi-structured telephone interviews were conducted based on the Swedish version of the Schedule for the Evaluation of Individual Quality of Life-Direct Weighting (SEIQoL-DW). Interviews were analysed using content analyses. When asked if cancer negatively or positively currently affected their lives, 68% reported at least one negative consequence and 53% at least one positive consequence. The most frequently reported negative consequences include a variety of physical impairments and limitations in participating in activities; positive consequences describe a more positive view of life and of self. Women more often than men reported negative psychological impact, a changed body appearance and positive interaction with others. CNS tumours and combined treatment were somewhat associated to a higher extent of negative consequences. Overall, the results indicate that long-term survivors of childhood cancer are getting along quite well despite shortcomings.
    European journal of oncology nursing: the official journal of European Oncology Nursing Society 11/2008; 13(3):164-70. DOI:10.1016/j.ejon.2008.05.009 · 1.79 Impact Factor
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    ABSTRACT: The aims of this study are to follow health-related quality of life (HRQOL), school attendance, and social interaction with friends in children with cancer and to explore potential relationships between HRQOL and school attendance. The study also describes self-reported reasons for not attending school and not meeting friends. During a 2-year period, all schoolchildren in Sweden starting treatment for cancer were invited to participate in the study. Participants (N = 101) were assessed 3 times during the first 5 months of treatment using 2 questionnaires: DISABKIDS Chronic Generic Module (DCGM-37) and a study-specific questionnaire. The results indicate a diminished HRQOL that remained stable over the study period, with girls rating worse HRQOL compared with boys. School attendance significantly increased over time, and approximately half of the children attended school 5 months after start of treatment. Self-reported HRQOL was positively correlated to days of school attendance. The results emphasize the importance of psychosocial care and nursing for children diagnosed with cancer, especially for girls. Research to further explore gender differences in HRQOL among children diagnosed for cancer is recommended.
    Journal of Pediatric Oncology Nursing 07/2008; 25(5):265-74. DOI:10.1177/1043454208321119 · 0.87 Impact Factor
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    ABSTRACT: In this qualitative study, we used grounded theory to explore the category of "overwhelming emotional expressions" that emerged in a previous study. Using theoretical sampling, 12 individual interviews were conducted with nurses in Swedish pediatric care. Overwhelming emotional expressions have been found to override nurses' professional preparedness; they continuously resolve this by protecting professional composure. Various strategies are used to protect professional composure, including rationalizing, controlled expression, power display, escape/avoidance, distancing, sharing, and management of space. Some of these strategies are similar to coping strategies. However, they differ in that they are about managing the situation and also include protecting the professional composure of the individual as well as the whole care situation. Nurses need to gain preparedness to meet overwhelming emotional expressions in transcultural care and to be aware of strategies for protecting professional composure so as to use them consciously and positively.
    Qualitative Health Research 06/2008; 18(5):647-57. DOI:10.1177/1049732308315736 · 2.19 Impact Factor
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    ABSTRACT: CXCL12 (SDF-1alpha) is a chemokine, which plays an important role in normal B-cell lymphopoesis, migration and homing to the bone marrow (BM) and previous studies have suggested a role for CXCL12 and its receptor CXCR4 in the pathogenesis of ALL. CXCL12 levels in serum were evaluated from ALL-children and controls. The biological effect of recombinant CXCL12 on primary leukaemic cells was investigated. Signalling via the CXCL12/CXCR4 axis was further characterized in an in vitro model using the pre-B leukaemic cell line Nalm-6. The serum level of CXCL12 in children at diagnosis of pre-B-ALL is significantly higher than in healthy children (4.8 (0-32) ng/ml vs. 0 (0-3.2) ng/ml, P < 0.001). After completed chemotherapy, CXCL12 decreases to levels comparable to those found in the control group. In addition, we found that recombinant CXCL12 enhances pre-B leukaemic cell proliferation in vitro. The CXCL12/CXCR4 axis is able to initiate functional signalling and we show that STAT5 is activated in CD19+ leukaemic cells from BM of ALL patients and in the leukaemic cell line Nalm-6. Our findings suggest that CXCL12 may have a role in leukaemic cell proliferation and survival during childhood ALL.
    Pediatric Blood & Cancer 04/2008; 50(4):812-7. DOI:10.1002/pbc.21370 · 2.56 Impact Factor
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    ABSTRACT: In this qualitative study we explored how health-care staff continuously resolve "obstacles to transcultural caring relationships" as they care for families with an immigrant background within the context of pediatric oncology care. A constant comparative method was used and data collection included 5 focus group interviews and 5 complementary individual interviews with health-care staff within pediatric oncology care. Bridging emerged as the way that health-care staff deal with obstacles to transcultural caring relationships. Bridging is a process in which various tools may be used and combined, including communicational tools, transcultural tools and organizational tools. Failure to use tools, or to use and combine them insufficiently, can bring the caring relationship to a halt, which leads to inequity in care. In order to ensure the provision of high-quality care despite differences in religion, culture, language and social situation, health-care staff need to bridge obstacles to transcultural caring relationships.
    European Journal of Oncology Nursing 03/2008; 12(1):35-43. DOI:10.1016/j.ejon.2007.07.006 · 1.79 Impact Factor
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    ABSTRACT: This qualitative study explores the caring situation of families with an immigrant background within the context of pediatric oncology care from the perspective of health care staff. Five focus group interviews and 5 complementary individual interviews were conducted after purposive and theoretical sampling, respectively. Grounded theory methodology revealed that obstacles to transcultural caring relationships are a main concern of the health care staff. These obstacles are divided into 4 main categories: linguistic, cultural and religious, social, and organizational. When health care staff fail to recognize obstacles to transcultural caring relationships, the result is inequity in care of families with an immigrant background. Equity in care for all does not mean identical treatment but, rather, care adjusted to the needs of the individual family regardless of background.
    Journal of Pediatric Oncology Nursing 12/2007; 24(6):314-28. DOI:10.1177/1043454207308066 · 0.87 Impact Factor
  • EJC Supplements 09/2007; 5(4):428-428. DOI:10.1016/S1359-6349(07)71563-X · 9.39 Impact Factor
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    ABSTRACT: One aspect of organizing medical follow-up for adult survivors of childhood cancer is to determine to what extent the former patient experiences a need for health services. In the present paper, we studied how the healthcare needs, both subjectively and objectively, were fulfilled for our former patients. 335 survivors over 18 y of age, with a follow-up time of more than 5 y after completion of therapy, were sent a questionnaire probing their present use of health services. The response rate was 73%. A majority (60%) of the survivors had no regular follow-up visits, and 42% of these reported that they missed not having one. More than one third were thus far dissatisfied with the follow-up programme. Only 3% of those who had regular follow-ups found them "unnecessary". Complaints subjectively related to their diseases or treatments were reported by 47%. Out of all responders, 34% did not miss having regular follow-up visits. Neither perceived disease-related complaints nor radiation therapy was a predictor for having a scheduled follow-up visit. In the absence of a long-term follow-up programme, many survivors were not receiving proper medical healthcare, whether from their perspective or from a professional one.
    Acta Paediatrica 09/2006; 95(8):922-8. DOI:10.1080/08035250600752441 · 1.84 Impact Factor
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    ABSTRACT: Palliative care is an important part of cancer treatment. However, little is known about how care-related factors affect bereaved intimates in a long-term perspective. We conducted a population-based, nationwide study addressing this issue, focusing on potential care-related stressors in parents losing a child to cancer. In 2001, we attempted to contact all parents in Sweden who had lost a child to cancer in 1992 to 1997. The parents were asked, through an anonymous postal questionnaire, about their experience of the care given and to what extent these experiences still affect them today. Information was supplied by 449 (80%) of 561 eligible parents. Among 196 parents of children whose pain could not be relieved, 111 (57%) were still affected by it 4 to 9 years after bereavement. Among 138 parents reporting that the child had a difficult moment of death, 78 (57%) were still affected by it at follow-up. The probability of parents reporting that their child had a difficult moment of death was increased (relative risk = 1.4; 95% CI, 1.0 to 1.8) if staff were not present at the moment of death. Ten percent of the parents (25 of 251 parents) were not satisfied with the care given during the last month at a pediatric hematology/oncology center; the corresponding figure for care at other hospitals was 20% (33 of 168 parents; P = .0163). Physical pain and the moment of death are two important issues to address in end-of-life care of children with cancer in trying to reduce long-term distress in bereaved parents.
    Journal of Clinical Oncology 01/2006; 23(36):9162-71. DOI:10.1200/JCO.2005.08.557 · 17.88 Impact Factor
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    ABSTRACT: CD27, a member of the TNF receptor family, plays an important role in lymphoid proliferation, differentiation and apoptosis. This study addresses the expression of CD27 and its ligand, CD70, in children with acute lymphoblastic leukemia (ALL) and the possible role of this receptor-ligand pair in the pathogenesis of ALL. Expression of CD27 and CD70 was evaluated with three-color flow cytometry in blood and bone marrow (BM) samples in children with ALL and controls. The biological role of these molecules on leukemic cell proliferation was studied in an in vitro culture system. The expression of the membrane bound CD27, as well as membrane bound CD70, on CD19(+) cells in the BM was significantly increased in ALL children compared to the expression found in the controls. Importantly, a substantial reduction in the in vitro proliferation of leukemic cells could be observed when the leukemic cells were cultured in presence of a blocking anti-human CD70 monoclonal antibody. The level of soluble CD27 (sCD27) in serum was also investigated and found to be significantly elevated in leukemic children as compared to healthy children. The high expression of CD27 and CD70 on ALL cells may represent an amplification of the normal CD27-CD70 expression present on early B cell progenitors. Our finding suggests that interference with CD27-CD70 interaction may represent novel treatment opportunities in ALL. Further studies are required to pin-point the role of this receptor-ligand pair in normal and malignant hematopoiesis.
    Experimental Hematology 01/2006; 33(12):1500-7. DOI:10.1016/j.exphem.2005.10.005 · 2.81 Impact Factor
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    ABSTRACT: The prognosis in childhood non-Hodgkin lymphoma (NHL) has improved dramatically during recent decades. The authors report the results from a 6-year population-based study of clinical characteristics and treatment results of NHL from the five Nordic countries. All children younger than 15 years of age at diagnosis with NHL diagnosed from 1995 to 2000 were stratified and treated according to immunophenotypic classification and stage of disease. A total of 230 patients were diagnosed with primary NHL, which gives an annual incidence of 0.9/100.000 children, with a median age of 8 years. Seven percent of the children were below 3 years of age at diagnosis. The male/female ratio was 2.3 and was unrelated to age. Patients with pre-B and T-cell NHL constituted 33%, B-cell NHL 53%, and anaplastic large cell lymphoma (ALCL) 14%. According to Murphy's classification, 14% had stage 1, 17% stage 2, 50% stage 3, and 19% stage 4 disease, 12 of whom (28%) had central nervous involvement (CNS) at diagnosis. By January 1, 2003, four children had died during induction, three children died in remission (2, 6, and 26 months from diagnosis), and 24 children experienced a relapse. At 5 years, the probability of event-free survival (p-EFS) was 86+/-2% for all children. The 5-year p-EFS values for stages 1 through 4 were 94%, 97%, 83%, and 79%, respectively. The 5-year p-EFS values were 91% for B-cell, 87% for pre-B, 81% for ALCL, and 79% for T-cell NHL. The 12 patients with CNS involvement at diagnosis had a significantly poorer outcome than stage 4 patients with CNS involvement (p-EFS = 50% vs. 90%, P < 0.01). The 218 patients without CNS disease at diagnosis had a 5-year p-EFS of 88%. With modern intensive chemotherapy, more than 85% of NHL patients will achieve long-lasting first remission. In the future, preventing death during induction and remission and improving therapy for patients with CNS disease would have a major impact on the overall p-EFS.
    Journal of Pediatric Hematology/Oncology 10/2004; 26(9):555-60. DOI:10.1097/01.mph.0000139772.98685.d2 · 0.96 Impact Factor
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    ABSTRACT: Thioguanine nucleotides (TGNs) mediate the cytotoxicity of mercaptopurine (MP). Methylated MP metabolites (formed by thiopurine methyltransferase [TPMT]) and methotrexate (MTX) polyglutamates can inhibit de novo purine synthesis. We explored whether dose adjustment of MP and MTX by erythrocyte (E) levels of TGN and MTX (including polyglutamates) could improve outcome in childhood acute lymphoblastic leukemia (ALL). A total of 538 children with ALL were randomly assigned to have their oral MP/MTX maintenance therapy adjusted by white cell counts (WBC), E-TGN, and E-MTX (pharmacology group), or by WBC only (control group). After a median follow-up of 7.8 years, 79 patients had relapsed. Cox regression analysis showed an increased risk of relapse for boys (P =.00003), high WBC at diagnosis (P =.03), pharmacology arm (6.6 times increased relapse hazard for girls), high TPMT activity (P =.002), and high average neutrophil counts during maintenance therapy (P =.0009), with a significant interaction between sex and randomization group (P =.0007). For girls, the relapse risk was 5% in the control group and 19% in the pharmacology group (P =.001) because of an increased relapse hazard during the first year after cessation of therapy. TPMT activity was the most significant predictor of relapses among girls in the pharmacology arm (P <.0001). Overall, the TPMT activity was higher for patients who relapsed after cessation of therapy compared with those who stayed in remission (girls 19.5 v 17.4 U/mL, P =.03; boys 19.3 v 18.0 U/mL, P =.04). Adding pharmacologically guided treatment intensification to dose adjustments by blood counts may not be warranted for girls, whereas new approaches to optimize maintenance therapy are needed for boys.
    Journal of Clinical Oncology 05/2003; 21(7):1332-9. DOI:10.1200/JCO.2003.04.039 · 17.88 Impact Factor
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    ABSTRACT: This study evaluates and describes disease-related distress in parents, with particular focus on the association between the time elapsed since the child's cancer diagnosis and a number of indicators of distress. In a cross-sectional design, 264 mothers and fathers of children with various malignancies completed a multidimensional questionnaire focusing on 11 illness-specific and general indicators of distress. Parents were assessed from 4 weeks to 14 years after the child's diagnosis, and age of children at onset of illness ranged from newly born to 21 years (mean approximately 6 years). The levels of distress related to loss of control, self-esteem, anxiety, depression, sleep disturbances, and psychological and physical distress were lower among parents for whom a longer period of time had elapsed from the time of diagnosis. However, the time elapsed could not explain all of the variation in these stress reactions, or any of the variation in uncertainty, disease-related fear and loneliness. The child's age at diagnosis and treatment situation at assessment were surpassed by time elapsed since diagnosis as predictors of variance in parental distress. The pattern observed indicates the presence of disease-related distress even years after the completion of medical treatment. The findings point to the need for research to identify parents at particular risk of suffering long-term harmful consequences from the prolonged stress of parenting a child with cancer. The necessity of longitudinal studies to evaluate the proportion of acute stress in relation to chronic or cumulative parental stress is emphasized.
    Acta Oncologica 02/2003; 42(2):137-46. DOI:10.1080/02841860310004995 · 3.71 Impact Factor
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    ABSTRACT: To evaluate viral vaccination immunity and booster responses in children treated successfully for acute lymphoblastic leukemia by chemotherapy and to study the response to treatment of antibody-producing plasma cells that are important for persistence of humoral immunity. Forty-three children who were in continuous first remission for a median of 5 years (range: 2-12 years) were studied. Before the leukemia was diagnosed, all children had been immunized against measles, mumps, and rubella according to the Swedish National immunization program. We analyzed levels of serum antibodies against measles and rubella by enzyme immunoassays. Avidity tests for measles antibodies were concomitantly performed by enzyme-linked immunosorbent assay for measles virus immunoglobulin G detection. The proportion of plasma cells in bone marrow was studied by flow cytometry at different times during treatment and follow-up. Children who lacked protective levels of antibodies to vaccination antigens were reimmunized. Serum was collected 3 months after immunization to assess vaccination responses. After completion of the treatment, only 26 of the 43 children (60%) were found to be immune against measles and 31 (72%) against rubella. The proportion of bone marrow plasma cells decreased during treatment but returned to normal after 6 months. Revaccination caused both primary and secondary immune responses. Six of the 14 children without immunity failed to achieve protective levels of specific antibodies against measles and 3 against rubella. Our finding of loss of antibodies against measles and rubella in children treated with intensive chemotherapy suggests that reimmunization of these patients is necessary after completion of the treatment. To determine reimmunization schedules for children treated with chemotherapy, vaccination responses need to be studied further.
    PEDIATRICS 07/2002; 109(6):e91. DOI:10.1542/peds.109.6.e91 · 5.30 Impact Factor
  • A Nilsson, O Björk
    Lakartidningen 01/2002; 98(50):5780.
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    ABSTRACT: A study is summarized analyzing the levels of serum antibodies against vaccination antigens in 43 children treated for acute lymphoblastic leukemia. Two different therapeutical regimens were used. All children had been immunized against measles and rubella before being diagnosed with leukemia. Eight of the 24 children treated 1986-1991 lacked protective levels of antibodies against measles; four of the 24 children lacked antibodies against rubella. In the second cohort of children (n = 16) treated from 1992 and onwards, nine lacked protective levels of antibodies against measles, eight lacked antibodies against rubella.
    Lakartidningen 12/2000; 97(45):5116-8.

Publication Stats

834 Citations
145.10 Total Impact Points


  • 1992–2010
    • Karolinska Institutet
      • Department of Women's and Children's Health
      Solna, Stockholm, Sweden
  • 1982–2009
    • Karolinska University Hospital
      • • Department of Clinical Pharmacology
      • • Department of Clinical Chemistry
      • • Department of Pediatric Radiology
      Tukholma, Stockholm, Sweden
    • Capio S:t Görans sjukhus
      Tukholma, Stockholm, Sweden
  • 2002
    • Hokkaido University
      • Department of Pediatrics
      Sapporo, Hokkaidō, Japan