Axillary recurrence rate 5 years after negative sentinel node biopsy for breast cancer.

BACKGROUND: Sentinel lymph node (SLN) biopsy has replaced axillary lymph node dissection (ALND) as the standard axillary staging procedure in breast cancer. Follow-up studies in SLN-negative women treated without ALND report low rates of axillary recurrence, but most studies have short follow-up, and few are multicentre studies. METHODS: Between September 2000 and January 2004, patients who were SLN-negative and did not have ALND were included in a prospective cohort. Kaplan-Meier estimates were used to analyse the rates of axillary recurrence and survival. The risk of axillary recurrence was also compared in centres with high and low experience with the SLN biopsy (SLNB) technique. RESULTS: A total of 2195 patients with 2216 breast tumours were followed for a median of 65 months. Isolated axillary recurrence was diagnosed in 1·0 per cent of patients. The event-free 5-year survival rate was 88·8 per cent and the overall 5-year survival rate 93·1 per cent. There was no difference in recurrence rates between centres contributing fewer than 150 SLNB procedures to the cohort and centres contributing 150 or more procedures. CONCLUSION: This study confirmed the low risk of axillary recurrence 5 years after SLNB for breast cancer without ALND.

CYP2C8 and CYP2C9 polymorphisms in relation to tumour characteristics and early breast cancer related events among 652 breast cancer patients.

BACKGROUND: CYP2C8/9 polymorphisms may influence breast cancer-free survival after diagnosis due to their role in the metabolism of tamoxifen, paclitaxel, and other chemotherapy. cytochrome P450 (CYP)2C8/9 metabolise arachidonic acid to epoxyeicosatrienoic acids, which enhance migration and invasion in vitro and promote angiogenesis in vivo. We aimed to investigate the frequency of CYP2C8/9 polymorphisms in relation to breast tumour characteristics and disease-free survival. METHODS: A prospective series of 652 breast cancer patients from southern Sweden was genotyped for CYP2C8*3, CYP2C8*4, CYP2C9*2, and CYP2C9*3. Blood samples and questionnaires were obtained pre- and postoperatively. Clinical information and tumour characteristics were obtained from patients' charts and pathology reports. RESULTS: Frequencies of CYP2C8/9 polymorphisms were similar to healthy European populations. Significantly less node involvement (P=0.002) and fewer PR+ tumours (P=0.012) were associated with CYP2C8*4. Median follow-up was 25 months and 52 breast cancer-related events were reported. In a multivariate model, CYP2C8/9*3/*1*/*2/*1 was the only factor associated with increased risk for early events in 297 tamoxifen-treated, ER-positive patients, adjusted HR 2.54 (95%CI 1.11-5.79). The effect appeared to be driven by CYP2C8*3, adjusted HR 8.56 (95%CI 1.53-51.1). CONCLUSION: Polymorphic variants of CYP2C8/9 may influence breast tumour characteristics and disease-free survival in tamoxifen-treated patients.

Sentinel lymph node biopsy in operations for recurrent breast cancer.

BACKGROUND: In a pilot prospective consecutive series on 50 patients with recurrent breast cancer, results of sentinel lymph node biopsy (SLNB) are reported. The interval between primary operation and recurrence was 8years (range 1-18years). Only three patients had not undergone dissection of the axilla (ALND). RESULTS: In 51% of patients scintigraphy disclosed sentinel nodes (SN). At operation SN was identified in 45% of patients corresponding to 83% of the SN's visualized by the scintigraphy. SN contained metastases in seven cases (16%), and the treatment plan was changed as a consequence of the SN examination. CONCLUSION: SLNB can identify SN at a high rate, and the findings may influence further planning of treatment. SLNB should be a future standard procedure in operations for recurrent breast cancer. Next step should be a randomized study.

Correlation-driven heavy-fermion formation in LiV2O4.

Optical reflectivity measurements were performed on a single crystal of the d-electron heavy-fermion (HF) metal LiV2O4. Our results evidence the highly incoherent charge dynamics above T* approximately 20 K and the redistribution of the spectral weight of the optical conductivity over broad energy scales ( approximately 5 eV) as the quantum coherence of the charge carriers is recovered. This reveals that LiV2O4 is close to a correlation-driven insulating state and indicates that, in sharp contrast to f-electron HF Kondo-lattice systems, strong electronic correlation effects dominate the heavy quasiparticle formation in LiV2O4.

Absence of conventional spin-glass transition in the Ising dipolar system LiHo(x)Y(1-x)F(4).

The magnetic properties of single crystals of LiHo(x)Y(1-x)F(4) with x = 16.5% and x = 4.5% were recorded down to 35 mK using a micro-SQUID magnetometer. While this system is considered as the archetypal quantum spin glass, the detailed analysis of our magnetization data indicates the absence of a phase transition, not only in a transverse applied magnetic field, but also without field. A zero-Kelvin phase transition is also unlikely, as the magnetization seems to follow a noncritical exponential dependence on the temperature. Our analysis thus unmasks the true, short-ranged nature of the magnetic properties of the LiHo(x)Y(1-x)F(4) system, validating recent theoretical investigations suggesting the lack of phase transition in this system.

Determination of sentinel lymph node (SLN) status in primary breast cancer by prospective use of immunohistochemistry increases the rate of micrometastases and isolated tumour cells: analysis of 174 patients after SLN biopsy.

AIM: The objective of the present study was to evaluate the prospective use of immunohistochemistry (IHC) for histopathological diagnosis of sentinel lymph node(s) (SLN) in primary breast cancer using stage migration and non-SLN metastases as endpoints in relation to metastatic involvement. METHOD: Serial sectioning and prospective use of IHC were applied to SLN examination in addition to routine haematoxylin-eosin staining in 174 consecutive patients with unifocal T1-T2 breast cancer included in a National Sentinel Node Study. Axillary lymph node dissection (ALND) was performed in all cases with macrometastases, micrometastases and isolated tumour cells (ITC). RESULTS: The SLN was found in 173/174 patients and a metastatic foci was found in 50 patients including 28/50 with macrometastases, 16/50 with micrometastases and 6/50 with ITC. IHC detected 3/16 of the micrometastases and 4/6 of ITC. Stage migration from N0 to N1mi was encountered in 3/132 patients by use of IHC. Non-SLN metastases were noted in 15/28 of patients with macrometastases and in 3/16 of patients with micrometastases, whereas no patient with ITC had additional metastases (p=0.007). CONCLUSION: The prospective use of IHC and serial sectioning for histopathological diagnosis of SLNs increased the detection rate of N1mi and ITC, but only 3/132 patients were stage-migrated by use of IHC. Patients with ITC did not have any risk of non-SLN metastases, supporting that ALND can safely be omitted in this group of patients.

Pathology parameters and adjuvant tamoxifen response in a randomised premenopausal breast cancer trial.

BACKGROUND: Subgroups of breast cancer that have an impaired response to endocrine treatment, despite hormone receptor positivity, are still poorly defined. Breast cancer can be subdivided according to standard pathological parameters including histological type, grade, and assessment of proliferation. These parameters are the net result of combinations of genetic alterations effecting tumour behaviour and could potentially reflect subtypes that respond differently to endocrine treatment. AIMS: To investigate the usefulness of these parameters as predictors of the response to tamoxifen in premenopausal women with breast cancer. MATERIALS/METHODS: Clinically established pathological parameters were assessed and related to the tamoxifen response in 500 available tumour specimens from 564 premenopausal patients with breast cancer randomised to either two years of tamoxifen or no treatment with 14 years of follow up. Proliferation was further evaluated by immunohistochemical Ki-67 expression. RESULTS: Oestrogen receptor positive ductal carcinomas responded as expected to tamoxifen, whereas the difference in recurrence free survival between control and tamoxifen treated patients was less apparent in the relatively few lobular carcinomas. For histological grade, there was no obvious difference in treatment response between the groups. The relation between proliferation and tamoxifen response seemed to be more complex, with a clear response in tumours with high and low proliferation, whereas tumours with intermediate proliferation defined by Ki-67 responded more poorly. CONCLUSIONS: Clinically established pathology parameters seem to mirror the endocrine treatment response and could potentially be valuable in future treatment decisions for patients with breast cancer.

Preoperative assessment of small tumours in women with breast cancer.

BACKGROUND AND OBJECTIVES: In patients with breast cancer, planning of the surgical strategy may rely on preoperative tumour size. The optimal method for assessment of small tumours has not been established. We compared findings from preoperative mammography and ultrasonography with histopathological tumour size in patients treated with breast-conserving surgery. MATERIAL AND METHODS: The study was retrospective and the setting a single institution clinic with free referral of patients. The patients were examined before the operation with mammography, ultrasonography, and findings were compared with postoperative histopathological tumour size. RESULTS: The study included 131 patients (median age was 59) years with grade I, II, and III cancers in 47, 71 and in 13 patients, respectively. The medium histological tumour size was 14 mm, range 4-45 mm. A wide 95% confidence interval between histopathological tumour size and preoperative mammography (standard deviation 4.8 mm) and ultrasonography (standard deviation 4.8 mm) was found. The combination of mammography and ultrasonography did not improve the results (standard deviation 4.3 mm). Preoperative mammography tended to over estimate the tumour size compared with histological tumour size whereas preoperative ultrasonography tended to underestimate the tumour size. CONCLUSION: In this retrospective study with preoperative evaluation of small breast cancers by mammography and ultrasonography, wide 95% confidence intervals for the methods were found and they should therefore be used with caution in the planning of the surgical strategy.

Breast conservation surgery, with and without radiotherapy, in women with lymph node-negative breast cancer: a randomised clinical trial in a population with access to public mammography screening.

The effect of postoperative radiotherapy after sector resection for stage I-II lymph node-negative breast cancer was evaluated in a patient population with access to public mammographical screening. 1187 women were randomised to no further treatment or postoperative radiotherapy following a standardised sector resection and axillary dissection. Radiation was administered to a dose of 48-54 Gy. Median age was 60 years, and median size of the detected tumours was 12 mm. Of the women 65% had their tumours detected by mammographical screening. The relative risk (RR) of ipsilateral breast recurrence was significantly higher in the non-irradiated patients compared with the irradiated patients, RR=3.33 (95% Confidence Interval (CI) 2.13-5.19, P<0.001). The corresponding cumulative incidence at 5 years was 14% versus 4%, respectively. Overall survival (OS) was similar, RR=1.16 (95% CI 0.81-1.65, P=0.41), with 5 year probabilities of 93 and 94%, respectively. Recurrence-free survival (RFS) at 5 years was significantly lower in the non-irradiated women, 77% versus 88% (P<0.001). Although women above 49 years of age, whose tumours were detected with mammographical screening, had the lowest rate of ipsilateral breast recurrence in this study, the cumulative incidence of such event amounted to 10% at 5 years if radiotherapy was not given. Such a recurrence rate has been considered as unacceptably high, but is, however, in the same range as that reported after lumpectomy and postoperative radiotherapy in published series.

Symmetrical temperature-chaos effect with positive and negative temperature shifts in a spin glass.

Aging in a Heisenberg-like spin glass Ag(11 at. % Mn) is investigated by measurements of the zero-field-cooled magnetic relaxation at a constant temperature after small temperature shifts absolute value of Delta T/T(g) < 0.012. A crossover from fully accumulative to nonaccumulative aging is observed, and by converting time scales to length scales using the logarithmic growth law of the droplet model, we find quantitative evidence that positive and negative temperature shifts cause an equivalent restart of aging (rejuvenation) in terms of dynamical length scales. This result supports the existence of a unique overlap length between a pair of equilibrium states in the spin-glass system.

Domain growth by isothermal aging in 3D Ising and Heisenberg spin glasses.

Nonequilibrium dynamics of three-dimensional model spin glasses, the Ising system Fe0.50Mn0.50TiO3 and the Heisenberg-like system Ag(11 at % Mn), has been investigated by measurements of the isothermal time decay of the low frequency ac susceptibility after a quench from the paramagnetic to the spin-glass phase. It is found that the relaxation data measured at different temperatures can be scaled according to predictions from the droplet scaling model, provided that critical fluctuations are accounted for in the analyses.

The Swedish Council on Technology Assessment in Health Care (SBU) systematic overview of chemotherapy effects in some major tumour types--summary and conclusions.

This report by The Swedish Council on Technology Assessment in Health Care (SBU) reviews, classifies, and grades the scientific literature on cancer chemotherapy in some major tumour types, describes the practice of chemotherapy in Sweden, compares practice with scientific knowledge, and analyses the costs and cost-effectiveness of chemotherapy. The report is intended primarily for decision-makers at various levels, both practitioners and administrators. It is also of interest for the medical profession. The extensive body of scientific literature was reviewed according to strict criteria that reflected the scientific weight of the literature. Sixteen experts representing different disciplines (oncology, surgery, internal medicine, health economy and quality of life research) participated in the literature review. Each section was discussed within the project group and was reviewed by at least one, but usually two international researchers. Additional input was provided by national experts representing different scientific disciplines. For the final evaluation to be as close to the objective truth as possible, a concerted effort was made to guarantee objectivity and thorough assessment of current knowledge about the effects of chemotherapy on the selected cancers. The tumour types selected for this assessment include firstly those types where three investigations had shown an increased use of chemotherapy in Sweden during the latest decade. These were non-small cell lung cancer (NSCLC), gastric cancer, pancreatic cancer, colorectal cancer and urinary bladder cancer. Secondly, the two tumour types comprising the greatest number of patients treated with chemotherapy in Sweden, breast cancer and haematological malignancies, were included. Among the haematological malignancies, the most prevalent ones, acute myeloid leukaemia (AML), chronic lymphocytic leukaemia (CLL), Hodgkin's disease (HD), aggressive non-Hodgkin's lymphoma (NHL) of the large B-cell type and indolent NHL of follicular type were evaluated. These constitute about 75%, of all haematological malignancies. Thirdly, ovarian cancer was included since chemotherapy has been extensively used and since, at the time of the planning of this overview, a group of very expensive drugs, the taxanes, had preliminarily shown promising results. A wealth of scientific literature has been published on cancer therapy. The review presented in this report is limited to scientific studies judged to be important for evaluating chemotherapy efficacy. Assessments of the content and quality of these studies, and a critical summary of the results in all stages of the selected tumours, have never before been attempted in this way. However, similar comprehensive overviews of certain stages of the tumours have previously been made. These overviews were also critically evaluated. Totally 1,496 studies involving 558,743 patients were reviewed. The survey of practice of chemotherapy use involved all departments of surgery, urology, gynaecology, internal medicine including haematologic units, pulmonary medicine and general and gynaecologic oncology at 16 hospitals in two health care regions in Sweden, covering 39% of the Swedish population. During the 4 weeks of the survey, all patients with the diagnoses concerned who received chemotherapy were registered. The study included 1,590 patients. The working group's general conclusions are summarised in the following points: The literature on the effects of chemotherapy is extensive. Chemotherapy has a well-documented role in the curative and palliative treatment of patients with several types of cancer. The use of chemotherapy is of utmost importance for the possibility of cure in certain tumour types. In other tumours, chemotherapy increases the possibility of cure when added to local and regional treatments, particularly surgery. In the instances of no possibility of cure, chemotherapy may to a variable extent improve both patient survival and well-being. In Sweden chemotherapy is largely used in accordance with that documented in the scientific literature. The extent of both over- and under-treatment seems to be limited but cannot be excluded at the individual patient level. The literature-based knowledge is scientifically of lower quality in the most chemotherapy sensitive tumours than in tumours showing more limited sensitivity. In the more sensitive tumours, positive effects on a symptomatic stage and survival were seen several decades ago. In those days, clinical treatment studies did not fulfil the current high quality requirements. Small life-prolonging effects of chemotherapy are sometimes very well documented in large, high quality scientific studies. Some of these s

A systematic overview of chemotherapy effects in breast cancer.

A systematic review of chemotherapy trials in several tumour types was performed by The Swedish Council of Technology Assessment in Health Care (SBU). The procedures for the evaluation of the scientific literature are described separately (Acta Oncol 2001; 40: 155-65). This synthesis of the literature on chemotherapy for breast cancer is based on 233 randomised studies, 9 meta-analysis of randomised studies, a population-based cohort study and 18 overviews/retrospective analyses including a total of 155,243 patients. The conclusions reached can be summarised into the following points: Adjuvant treatment-- There is solid scientific support from randomised studies that adjuvant polychemotherapy at 10 years will result in an absolute mortality reduction for patients younger than 50 years by 12% for node positive (34% relative mortality reduction corresponding to an estimated median survival prolongation of several years) and 6% for node negative patients. For women aged 50 to 69 years, the corresponding figures for node positive and node negative patients are 6% and 2%, respectively (approximately 11% relative mortality reduction). Anthracycline-containing combinations result in an absolute survival benefit at five years of 3%, compared with non-anthracycline based polychemotherapy. There are indications that the taxane paclitaxel may further improve the survival compared with anthracyclines. However, the limited data preclude conclusions for the routine care. The addition of tamoxifen to chemotherapy further enhances the survival benefit for receptor positive subgroups. The roles of more dose-intensive regimens, including high-dose therapy with stem cell support, are presently studied in randomised investigations. The data presented so far are conflicting but they do not in general support high-dose therapy. Quality of life, based on analyses of randomised studies, demonstrate that adjuvant polychemotherapy has an initial detrimental effect, but long-term follow-up of treated patients demonstrates no impairment of quality of life compared with untreated patients. Polychemotherapy in standard doses should be offered to premenopausal node positive patients, and the corresponding postmenopausal group with a receptor-negative breast cancer and to node negative patients with high risk factors. Polychemotherapy should be combined with tamoxifen to all patients with receptor-positive tumours. Due to a need of more knowledge in this field, patients should be included in investigational protocols. Locally advanced breast cancer-- Based on current knowledge, treatment of patients with locally advanced breast cancer should include neoadjuvant/preoperative polychemotherapy since there is evidence from controlled studies that such therapy will statistically significantly increase the number of patients who can be offered breast-conserving surgery. Indirect comparisons also demonstrate survival improvements, but the scientific support is equivocal. Metastatic breast cancer-- The median survival for patients with metastatic disease treated with conventional chemotherapy doses and regimens is 12 to 24 months. Retrospective cohort studies indicate that the use of non-anthracycline containing chemotherapy compared with no chemotherapy might add a survival gain of six to nine months. However, this estimation is based on equivocal data. Based on overview data, polychemotherapy results in a statistically significant survival gain compared with single-agent therapy. Based on repeated randomised studies, the addition of anthracyclines increases the response rate and statistically significantly improves the survival compared with non-anthracycline containing chemotherapy, except for CMF combined with prednisone/prednisolone, which will statistically significantly improve the survival compared with some anthracycline combinations. Second line therapy using vinorelbine or docetaxel is statistically significantly better than other regimens with a time to progression and survival benefit in the order of one to three months based on few randomised studies. The role, if any, of third line therapy is yet to be demonstrated. In the metastatic setting, conventional chemotherapy improves the quality of life. In standard care, first line therapy should contain an anthracycline and second line therapy using vinorelbine or docetaxel could be offered to selected patients failing first line therapy. Based on numerous randomised studies, breast cancer demonstrates a positive dose-response relationship both in the adjuvant situation and for metastatic disease. However, in the conventional dose-range there seems to be a plateau in the dose-response curve, with no further survival gains for high

Long term results of a randomized study by the Swedish Melanoma Study Group on 2-cm versus 5-cm resection margins for patients with cutaneous melanoma with a tumor thickness of 0.8-2.0 mm.

BACKGROUND: Large, prospective, randomized trials with long term follow-up are required to obtain an unbiased evaluation of the significance of resection margins in patients with cutaneous melanoma. METHODS: The Swedish Melanoma Study Group performed a prospective, randomized, multicenter study of patients with primary melanoma located on trunk or extremities and with a tumor thickness > 0.8 mm and 0.8 mm thick and

A pharmacokinetic study of 5-FU/leucovorin and alpha-interferon in advanced cancer.

The present study was designed to study 5-FU pharmacokinetics after interferon. Weekly bolus 5-FU (500 mg/m2), immediately followed by leucovorin (60 mg/m2) was given in 14 weekly cycles to 55 gastrointestinal and breast cancer patients. Interferon-alpha was given on days 2, 4 and 6, starting from cycle 2 at a dose of 0.5 million units (MU) and stepwise increased to 12 MU in cycles 12 and 13. Five patients could not tolerate the treatment even at the lowest dose of interferon and 22 patients were unavailable for the pharmacokinetic analysis because of dose reductions of 5-FU. Five patients were able to follow the protocol to 12 MU, whereas most patients were unable to continue owing to toxicity. 5-FU pharmacokinetics was analysed every second cycle. Peak concentration and AUC were increased after 12 MU of interferon, but no other significant influence of interferon on pharmacokinetic parameters of 5-FU was observed.

Resection margins of 2 versus 5 cm for cutaneous malignant melanoma with a tumor thickness of 0.8 to 2.0 mm: randomized study by the Swedish Melanoma Study Group.

BACKGROUND: The traditional surgical treatment for primary malignant melanoma has often been a wide excision with a margin of about 5 cm. Since the risk of local recurrences is dependent on tumor thickness, thin tumors (<1 mm) have routinely been excised with a narrow margin. For thick tumors, the optimal resection margin is controversial, and can be determined only by prospective, randomized trials. METHODS: The Swedish Melanoma Study Group performed a prospective, randomized multicenter study to evaluate an excision margin of 2 versus 5 cm for patients with cutaneous malignant melanoma with tumor thickness > 0.8 and < or = 2.0 mm. The trial includes 769 patients. Patients with melanomas of the skin of the head, neck, hands, feet, or vulva were not included in the trial. In the event of an excision biopsy for diagnosis, radical surgery was completed within 6 weeks. The median follow-up time was 5.8 years for estimation of survival and 4.0 years for diagnosis of recurrent disease. RESULTS: No significant differences have been observed between the treatment groups regarding local or regional recurrences or survival. CONCLUSIONS: We recommend an excision with a margin of 2 cm for cutaneous malignant melanoma with a tumor thickness > 0.8 and < or = 2.0 mm.

Proliferation of the breast epithelium in relation to menstrual cycle phase, hormonal use, and reproductive factors.

The proliferative rate in normal breast epithelium from 58 women undergoing reduction mammoplastics was studied using the formalin resistant antibody Ki-S5, and related to age at operation, menstrual cycle phase, family history of breast cancer, height and weight, parity, and hormonal use. The breast tissue from women operated on in the luteal menstrual cycle phase (day 15-28 among oral contraceptive (OC) users) had significantly higher proliferative rate than breast tissue removed from women in the follicular phase (day 1-14) (p = 0.01). Among women presently exposed to hormones, those with a positive family history of breast cancer among first and second degree relatives had significantly higher values than cases without such history (p = 0.02). Weight was not significantly related to proliferation rate, while a short height was associated with a significantly higher proliferation rate (p = 0.04). Women who used OCs before the first full-term pregnancy (FFTP) had a significantly higher proliferation rate compared with never users or late users (p = 0.04). No significant difference was seen between parous versus nulliparous women. The results from the univariate analysis persisted in multivariate models. An especially high proliferation rate was seen in young women with both a positive family history and present hormonal use (p = 0.001). Overall, it was found that young women had a non-significantly higher proliferation rate than older women (p = 0.10). Due to small sample size, these results must be regarded as preliminary, especially in the subgroup analyses.

Treatment of liver metastases from colorectal cancer with hepatic artery occlusion, intraportal 5-fluorouracil infusion, and oral allopurinol. A randomized clinical trial.

BACKGROUND: Regional therapy for colorectal liver metastases aimed at prolonging survival has not been tested fully in a randomized trial with untreated control subjects. This study explored the efficacy of temporary hepatic artery occlusion followed by intraportal infusion of 5-fluorouracil (5-FU) and oral allopurinol as biochemical modulators in prolonging the survival of patients with nonresectable liver metastases and no extrahepatic cancer. METHODS: Eighty-four patients were considered for randomization, of whom 24 were excluded at laparotomy because of extrahepatic cancer (n = 17) or resectable lesions (n = 5). In two patients, no cancer was identified in the liver. Thirty-two patients were allocated to receive treatment, and 28 were allocated to receive no regional or systemic treatment. Six patients were excluded after randomization because of major protocol violations. RESULTS: The median survival time for patients was 17 months (range, 0-66), and for control subjects, the median was 8 months (range, 0-31). Log rank analysis demonstrated a significant survival benefit for treatment versus no treatment (P = 0.0039). (In two patients, early death was due to toxicity from the wrong dose of 5-FU and the wrong route of administration, respectively; the mean and median survival were reduced by 1 month). CONCLUSION: This study identified a treatment modality that prolongs survival in patients with nonresectable liver metastases and no extrahepatic metastases from colorectal cancer, suggesting that control subjects receiving no therapy may not be necessary in future randomized trials.

Use of sunbeds or sunlamps and malignant melanoma in southern Sweden.

In a population-based, matched case-control study from the South Swedish Health Care Region, which has the highest risk for melanoma in Sweden, the relation between the use of sunbeds or sunlamps and malignant melanoma was investigated. Between July 1, 1988, and June 30, 1990, a total of 400 melanoma patients and 640 healthy controls aged 15-75 years answered a comprehensive questionnaire containing different epidemiologic variables. Questions regarding the use of sunbeds or sunlamps were included. The odds ratio for developing malignant melanoma after ever having used sunbeds or sunlamps was 1.3. Considering all age groups, the odds ratio was significantly elevated after exposure more than 10 times a year to sunbeds or sunlamps (odds ratio (OR) = 1.8). When the study was restricted to patients and controls younger than age 30 years because the use of tanning devices is much more common among young persons, the odds ratio was higher (OR = 7.7 for more than 10 times a year vs. none). These findings were independent of constitutional factors and factors regarding sun exposure. A dose-response relation was evident. Furthermore, among melanoma patients in this young age group, the ratio of females to males was significantly higher than in older patients. When different melanoma presentation sites were considered, only lesions of the trunk were significantly associated with sunbed or sunlamp use (OR = 4.2 for more than 10 times a year vs. none).