Work status changes and associated factors in a nationwide sample of Norwegian long-term breast cancer survivors

PURPOSE

The study aims to describe work status at diagnosis and 8 years post-diagnosis in a nationwide sample of breast cancer survivors (BCSs), and investigate associated and self-reported factors of reduced work status.

METHODS

Women aged 20-65 years when diagnosed with stage I-III breast cancer (BC) in 2011 or 2012 were invited to participate in a questionnaire study in 2019 (n = 2803), of whom 49% (n = 1361) responded. For this sub-study, we included 974 BCSs below the legal retirement age in Norway (< 67 years) at survey and with complete work status data. Reduced work status was defined as being in paid work at BC diagnosis and not working at time of survey. Logistic regression analyses were applied to identify factors associated with reduced work status.

RESULTS

Of BCSs who were in paid work at diagnosis (n = 845), 63% maintained their work status to 8 years later. Reduced work status was associated with not living with children (OR .44, 95% CI .24-.82), age (OR 1.16, 95% CI 1.11-1.21), chemotherapy (OR 2.83, 95% CI 1.24-6.61), > 2 comorbid conditions (OR 2.27, 95% CI 1.16-4.32), cognitive function (OR .99, 95% CI .98-.99), fatigue (OR 1.02, 95% CI 1.01-1.03), and neuroticism (OR 1.57, 95% CI 1.00-2.46). BC and late effects were reported as reasons for reduced work status and disability.

CONCLUSIONS

The majority of BCSs who were in paid work at diagnosis were working 8 years later.

IMPLICATIONS FOR CANCER SURVIVORS

Our results suggest a need to focus on fatigue and reduced cognitive function among long-term BCSs, with the ultimate aim of improving work sustainability.

Implementation and clinical benefit of DPYD genotyping in a Danish cancer population

BACKGROUND

In 2020, the European Medicines Agency recommended testing patients for dihydropyrimidine dehydrogenase (DPD) deficiency before systemic treatment with fluoropyrimidines (FP). DPD activity testing identifies patients at elevated risk of severe FP-related toxicity (FP-TOX). The two most used methods for DPD testing are DPYD genotyping and DPD phenotyping (plasma uracil concentration). The primary objective of this study was to compare the overall frequency of overall grade ≥3 FP-TOX before and after the implementation of DPYD genotyping.

PATIENTS AND METHODS

Two hundred thirty Danish, primarily gastrointestinal cancer patients, were DPYD-genotyped before their first dose of FP, and blood was sampled for post hoc assessment of P-uracil. The initial dose was reduced for variant carriers. Grade ≥3 FP-TOX was registered after the first three treatment cycles of FP. The frequency of toxicity was compared to a historical cohort of 492 patients with post hoc determined DPYD genotype from a biobank.

RESULTS

The frequency of overall grade ≥3 FP-TOX was 27% in the DPYD genotype-guided group compared to 24% in the historical cohort. In DPYD variant carriers, DPYD genotyping reduced the frequency of FP-related hospitalization from 19% to 0%. In the control group, 4.8% of DPYD variant carriers died due to FP-TOX compared to 0% in the group receiving DPYD genotype-guided dosing of FP. In the intervention group, wild-type patients with uracil ≥16 ng/ml had a higher frequency of FP-TOX than wild-type patients with uracil <16 ng/ml (55% versus 28%).

CONCLUSIONS

We found no population-level benefit of DPYD genotyping when comparing the risk of grade ≥3 FP-TOX before and after clinical implementation. We observed no deaths or FP-related hospitalizations in patients whose FP treatment was guided by a variant DPYD genotype. The use of DPD phenotyping may add valuable information in DPYD wild-type patients.

P1533 Early evaluation of global longitudinal strain and biomarkers at initiation of trastuzumab treatment in breast cancer patients

Funding Acknowledgements

The Danish Heart Foundation, Copenhagen (grant number: 14-R97-A5188-22839 and 15-R99-A5940). The Research Fond of the Region of Southern Denmark.

Background

Global longitudinal strain (GLS) is recommended to detect subclinical changes preceding reduced left ventricular ejection fraction (LVEF) in trastuzumab related cardiotoxicity. The possibility to detect signs of acute myocardial deterioration at treatment initiation is not thoroughly investigated. Accordingly, the aim of this study was to assess changes in GLS and biomarkers within the first two weeks of trastuzumab treatment.

Methods

In a prospective cohort study 45 patients with non-metastatic breast cancer (age 54, LVEF 62.8% (SD ± 3.6), GLS -19.9% (SD ± 2.1), 40% hypertension) were included. Examinations including echocardiography and measurement of troponin T and NT-proBrain Natriuretic Peptide were conducted before initiation of trastuzumab, at day 3, 7 and 14 and after 3, 6 and 9 months.

Results

A significant deterioration in LVEF, GLS, s’, e’ septal and s’RV occurred during the 9 months study period and was proceed by significant changes in all these parameters within the first 14 days.

After 14 days 12 patients (27%) had an increase in GLS ≥10 %, which was associated with significantly lower LVEF at nine month at 55.2% (SD ± 4.1) vs. 59.5% (SD ± 3.5) (p = 0.001) compared to patients with &lt;10 % early increase in GLS (Figure 1). No difference in plasma concentrations of cardiac biomarkers was observed between the two groups.

Conclusion

In this cohort study deteriorations in key echocardiographic parameters were detected within the first two weeks of trastuzumab treatment, and an early 10 % increase in GLS was associated with a lower LVEF at nine months.

Abstract P1533 Figure 1

Effect of cryotherapy on dose of adjuvant paclitaxel in early-stage breast cancer

BACKGROUND

Chemotherapy-induced peripheral neuropathy (CIPN) is a dose-limiting toxicity of paclitaxel. Though no pharmacological agents have been identified to prevent CIPN, cryotherapy with frozen gloves and socks may reduce the risk of developing CIPN and thereby increase the likelihood of patients completing the planned dose of paclitaxel.

PATIENTS AND METHODS

Among women with early-stage breast cancer who received at least one cycle of paclitaxel, 119 were included in the 2016 cohort who received cryotherapy when they developed symptoms of CIPN, and 96 patients in the 2017 cohort who received prophylactic cryotherapy. From electronic patient records, data were abstracted on dates and doses of adjuvant paclitaxel, dose reductions, cycle delays, symptoms of CIPN, and whether and when frozen gloves and socks were used. The outcome was the proportion of patients completing the planned 720 mg/m² of paclitaxel cumulated over nine cycles. The hazard ratio (HR) of a dose-limiting event due to CIPN was estimated in a Cox proportional hazards model.

RESULTS

In the 2016 cohort, cryotherapy was needed due to symptoms of CIPN in 54 (45%) patients. Significantly, more patients, 77% in the 2017 cohort, completed the planned dose of 720 mg/m² compared with 64% in the 2016 cohort, p = 0.017. The HR of a dose reduction or cessation due to CIPN, adjusted for age and HER-2 status, was 0.50 (95% confidence interval 0.30-0.84), p = 0.009, for the 2017 cohort compared with the 2016 cohort.

CONCLUSIONS

The results of this study suggest that prophylactic cryotherapy may reduce the risk of a dose-limiting event due to CIPN and increase the proportion of patients completing the planned dose of paclitaxel in adjuvant treatment of early-stage breast cancer. Despite this, CIPN remains to be an important dose-limiting toxicity of paclitaxel.

Abstract S6-03: DBCG 07-READ: A randomized phase III trial comparing six cycles of docetaxel and cyclophosphamide (DC) to three cycles of epirubicin and cyclophosphamide followed by three cycles of docetaxel (EC-D) in patients with early breast cancer

Background: DBCG 07-READ was designed to compare sequential EC followed by D with DC in patients with early, TOP2A normal breast cancer as a retrospective evaluation of the DBCG 89D trial suggested that these patients would not benefit from an anthracycline.

Methods: This is a multicenter open-label randomized phase III trial. Three groups of women were eligible following completely resected unilateral invasive TOP2A normal (TOP2A gene to centromere 17 ratio of 0.8 to 2.0) breast cancer by mastectomy or breast conserving surgery in combination with axillary clearance or a negative sentinel node biopsy; 1: Age 18 to 39 years; 2: Age 40 to 75 years and estrogen receptor (ER) negative (&lt;10% positive) and/or HER2 positive tumor; and 3: Age 40 to 59 years and ER ≥ 10% positive and either node positive, ductal carcinoma and grade II-III, or tumor size &gt; 20 mm. Eligible patients were required to have a Charlson Comorbidity (CC) Index &lt; 2 and to be without signs of distant metastasis. Patients were randomized to receive 6 cycles of DC (docetaxel 75 mg/m2 and cyclophosphamide 600 mg/m2) every 3 weeks or 3 cycles of EC (epirubicin 90 mg/m2 and cyclophosphamide 600 mg/m2) followed by 3 cycles of D (docetaxel 100 mg/m2) every 3 weeks. In case of a CC Index of 1 or 2 chemotherapy was administered at a reduced dose-intensity. Adjuvant endocrine treatment, trastuzumab and radiotherapy were administered according to the guidelines of the DBCG. The primary endpoint was disease-free survival (DFS), and secondary endpoints were overall survival (OS) and distant disease-free survival (DDFS).

Results: Between July 2008 and December 2012 we (12 DBCG centers) randomly assigned 2006 eligible patients to DC (N=1008) or EC-D (N=998). Patient and tumor characteristics were balanced by treatment groups. The median estimated potential follow-up is 5.4 years and the 5-year DFS was 88.0%; 95% CI 85.8 to 90.0 in the EC-D arm and 87.9%; 95% CI 85.7 to 89.9 in the DC arm. No significant difference in the risk of DFS events HR=1.03; 95% CI 0.80 to 1.32; p=0.84 or mortality HR=1.11; 95% 0.79 to 1.56; p=0.55 was observed in the intent to treat analysis. Patient-reported toxicity will be compared for the two chemotherapy regimens.

Conclusion: The READ trial gives evidence to support no outcome benefit from anthracycline in patients with TOP2A normal ealy breast cancer.

Citation Format: Ejlertsen B, Tuxen MK, Jakobsen EH, Jensen M-B, Knoop AS, Hoejris I, Ewertz M, Balslev E, Vestlev PM, Kenholm J, Nielsen DL, Bechmann T, Andersson M, Cold S, Nielsen HM, Maae E, Carlsen D, Mouridsen HT. DBCG 07-READ: A randomized phase III trial comparing six cycles of docetaxel and cyclophosphamide (DC) to three cycles of epirubicin and cyclophosphamide followed by three cycles of docetaxel (EC-D) in patients with early breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr S6-03.

Abstract P2-16-04: A phase 2 study of ridaforolimus (RIDA) and dalotuzumab (DALO) in estrogen receptor positive (ER+) breast cancer

Background: Preclinical studies indicate that the dual inhibition of IGFR and mTOR may be additive or synergistic and abrogates the feedback activation of AKT due to rapamycin analog mTOR inhibitors. A phase 1 study of the mTOR inhibitor RIDA and the anti-IGFR antibody DALO demonstrated that the combination was feasible and well-tolerated at doses that were nearly those used for the two single agents. The dose limiting toxicity was stomatitis, similar to RIDA monotherapy. Preliminary signals of anti-tumor activity, including partial responses and prolonged progression free survival (PFS), were observed in ER+ advanced breast cancer (ABC), especially in high proliferation tumors (Ki67 ≥15%). Methods: The trial was a multi-center, international randomized study with PFS as the primary endpoint. Key eligibility included ABC with prior treatment with a non-steroidal aromatase inhibitor. The original phase 2 study design was a two-part, adaptive design intended to first test the combination of RIDA (30 mg by mouth daily for 5 out of every 7 days), -DALO (10 mg/kg IV weekly) against a standard agent, exemestane in Part A. Patients were stratified into high and low proliferation strata based on baseline Ki67. Following a demonstration of PFS benefit of the combination in Part A, Part B was intended to show the PFS benefit of the combination over each single agents by comparing RIDA-DALO to RIDA and DALO. Results: The study was initiated in October 2011. Accrual was suspended after the first 66 patients were randomized due to a higher than expected rate of stomatitis in the RIDA-DALO arm. Preliminary data indicated an overall incidence of any grade stomatitis was 68% (22/33 pts), and of grade 3 stomatitis was 35% (11/33 pts). In an effort to identify a more tolerable regimen, the study was amended to eliminate Part B and to evaluate two sequential reduced dose RIDA-DALO cohorts in a non-randomized design: 20mg and 10mg for 5 out of every 7 days. The dose of DALO was unchanged. Preliminary safety results of overall and grade 3 stomatitis in the 20 mg were 81.5% (22/27 pts) and 37% (10/27 pts), respectively. Although the incidence of overall stomatitis in the 10 mg cohort remained high, 88% (22/25 pts), grade 3 stomatitis was dramatically reduced to 8% (2/25 pts). Conclusion: Preliminary evaluation of safety from this phase 2 study demonstrates that the previously recommended phase 2 dose of RIDA-DALO was not tolerable. However lower doses of RIDA (10 mg) in combination with DALO appeared to be tolerable with markedly reduced rates of grade 3 stomatitis. Final results of efficacy, safety and RNA profiling analysis from the two RIDA-DALO dose cohorts as well as from the randomized portion of the study will be available at the time of the meeting.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-16-04.

Influence of comorbidity on the effect of adjuvant treatment and age in patients with early-stage breast cancer

Background:

Prevalence of comorbidity at breast cancer diagnosis increases with age and is likely to influence the likelihood of receiving treatment according to guidelines. The aim of this study was to examine the effect of breast cancer treatment on mortality, taking age at diagnosis and comorbidity into account.

Methods:

Four nationwide population registries in Denmark: the Danish Civil Registration System, the Danish Breast Cancer Cooperative Group, the Danish National Patient Register, and the Danish Register of Causes of Death provided information on 62 591 women diagnosed with early-stage breast cancer, 1990–2008, of whom data on treatment were available for 39 943. Comorbidity was measured using the Charlson Comorbidity Index. Adjuvant treatment were categorised as none, chemotherapy, endocrine therapy, and unknown. Multivariable Cox modelling assessed the effect of comorbidity on breast cancer-specific mortality and other cause mortality according to treatment, adjusting for age at diagnosis and other clinical prognostic factors.

Results:

The impact of comorbidity on mortality was most pronounced in patients aged 50–79 years. Patients receiving chemotherapy with mild to moderate comorbidity had HR 0.99 (95% confidence interval (CI); 0.82–1.19) and 1.06 (95% CI; 0.77–1.46) for breast cancer-specific mortality, respectively, compared with patients without comorbidity.

Conclusion:

Comorbidity at breast cancer diagnosis is an independent adverse prognostic factor for death after breast cancer. We identified a subgroup of patients with mild to moderate comorbidity receiving chemotherapy who had similar breast cancer mortality as patients with no comorbidity.

Breast cancer incidence by estrogen receptor status in Denmark from 1996 to 2007

During the past 50 years, breast cancer incidence has increased by 2-3 % annually. Despite many years of testing for estrogen receptors (ER), evidence is scarce on breast cancer incidence by ER status. The aim of this paper was to investigate the increase in breast cancer incidence by ER status. Data were obtained from the clinical database of the Danish Breast Cancer Cooperative Group which holds nationwide data on diagnosis, including pathology, treatment, and follow-up on primary breast cancers since 1977. All Danish women <80 years diagnosed with primary breast cancer 1996-2007 were identified in this prospective register based study. ER status was evaluated using immunohistochemical staining by standardized laboratory methods in the Danish Pathology Departments and reported to the database. From 1996 to 2007, breast cancer incidence increased overall with a tendency to level off after 2002. In all women a significant decrease was found in ER unknown tumors. However, in both pre- and postmenopausal women, significant increases were seen in incidence of ER+ tumors; though the increase levelled off for premenopausal women after 2002. In postmenopausal women, the incidence of ER- breast cancer decreased significantly throughout the period. In women <35 years, we found a minor non-significant increase in both ER+ and ER- tumors. ER unknown decreased in all women and was the most distinct in premenopausal women aged 35+. We found a significant increase in ER+ breast cancer incidence in postmenopausal women whereas the incidence in premenopausal women (aged 35+) levelled off after 2002.

PIK3CA mutations, PTEN, and pHER2 expression and impact on outcome in HER2-positive early-stage breast cancer patients treated with adjuvant chemotherapy and trastuzumab

BACKGROUND

This study was conducted to determine the frequency of PIK3CA mutations and human epidermal growth factor receptor-2 (HER2) phosphorylation status (pHER2-Tyr1221/1222) and if PIK3CA, phosphatase and tensin homolog (PTEN), or pHER2 has an impact on outcome in HER2-positive early-stage breast cancer patients treated with adjuvant chemotherapy and trastuzumab.

PATIENTS AND METHODS

Two hundred and forty HER2-positive early-stage breast cancer patients receiving adjuvant treatment (cyclophosphamide 600 mg/m2, epirubicin 60 mg/m2, and fluorouracil 600 mg/m2) before administration of 1 year trastuzumab were assessable. PTEN and pHER2 expression were assessed by immunohistochemistry. PIK3CA mutations (exons 9 and 20) were determined by pyrosequencing.

RESULTS

Five-year overall survival (OS) and invasive disease-free survival were 87.8% and 81.0%, respectively. Twenty-six percent of patients had a PIK3CA mutation, 24% were PTEN low, 45% pHER2 high, and 47% patients had increased PI3K pathway activation (PTEN low and/or PIK3CA mutation). No significant correlations were observed between the clinicopathological variables and PIK3CA, PTEN, and pHER2 status. In both univariate and multivariate analyses, patients with PIK3CA mutations or high PI3K pathway activity had a significant worse OS [multivariate: hazard ratio (HR) 2.14, 95% confidence interval (CI) 1.01-4.51, P=0.046; and HR 2.35, 95% CI 1.10-5.04, P=0.03].

CONCLUSION

Patients with PIK3CA mutations or increased PI3K pathway activity had a significantly poorer survival despite adequate treatment with adjuvant chemotherapy and trastuzumab.

Effect of radiotherapy after breast-conserving surgery on 10-year recurrence and 15-year breast cancer death: meta-analysis of individual patient data for 10,801 women in 17 randomised trials

BACKGROUND

After breast-conserving surgery, radiotherapy reduces recurrence and breast cancer death, but it may do so more for some groups of women than for others. We describe the absolute magnitude of these reductions according to various prognostic and other patient characteristics, and relate the absolute reduction in 15-year risk of breast cancer death to the absolute reduction in 10-year recurrence risk.

METHODS

We undertook a meta-analysis of individual patient data for 10,801 women in 17 randomised trials of radiotherapy versus no radiotherapy after breast-conserving surgery, 8337 of whom had pathologically confirmed node-negative (pN0) or node-positive (pN+) disease.

FINDINGS

Overall, radiotherapy reduced the 10-year risk of any (ie, locoregional or distant) first recurrence from 35·0% to 19·3% (absolute reduction 15·7%, 95% CI 13·7-17·7, 2p<0·00001) and reduced the 15-year risk of breast cancer death from 25·2% to 21·4% (absolute reduction 3·8%, 1·6-6·0, 2p=0·00005). In women with pN0 disease (n=7287), radiotherapy reduced these risks from 31·0% to 15·6% (absolute recurrence reduction 15·4%, 13·2-17·6, 2p<0·00001) and from 20·5% to 17·2% (absolute mortality reduction 3·3%, 0·8-5·8, 2p=0·005), respectively. In these women with pN0 disease, the absolute recurrence reduction varied according to age, grade, oestrogen-receptor status, tamoxifen use, and extent of surgery, and these characteristics were used to predict large (≥20%), intermediate (10-19%), or lower (<10%) absolute reductions in the 10-year recurrence risk. Absolute reductions in 15-year risk of breast cancer death in these three prediction categories were 7·8% (95% CI 3·1-12·5), 1·1% (-2·0 to 4·2), and 0·1% (-7·5 to 7·7) respectively (trend in absolute mortality reduction 2p=0·03). In the few women with pN+ disease (n=1050), radiotherapy reduced the 10-year recurrence risk from 63·7% to 42·5% (absolute reduction 21·2%, 95% CI 14·5-27·9, 2p<0·00001) and the 15-year risk of breast cancer death from 51·3% to 42·8% (absolute reduction 8·5%, 1·8-15·2, 2p=0·01). Overall, about one breast cancer death was avoided by year 15 for every four recurrences avoided by year 10, and the mortality reduction did not differ significantly from this overall relationship in any of the three prediction categories for pN0 disease or for pN+ disease.

INTERPRETATION

After breast-conserving surgery, radiotherapy to the conserved breast halves the rate at which the disease recurs and reduces the breast cancer death rate by about a sixth. These proportional benefits vary little between different groups of women. By contrast, the absolute benefits from radiotherapy vary substantially according to the characteristics of the patient and they can be predicted at the time when treatment decisions need to be made.

FUNDING

Cancer Research UK, British Heart Foundation, and UK Medical Research Council.

Phase II trial of vinorelbine (V) days 1+8 every 3 weeks and trastuzumab (T) weekly as first-line chemotherapy for HER2+ metastatic breast cancer (MBC)

1091

Background: Weekly V and T as 1. line therapy in patients (pts) with HER2+ MBC is highly effective with reported response rates (RR) from 61–86% and median time to progression (TTP) 8.5–16 months. This study examined V given twice every 3 weeks. Methods: Eligible pts had HER2+ (IHC 3+ or FISH) MBC with measurable disease by RECIST criteria, no prior chemotherapy or T for MBC, and LVEF > 50%. They received V 35 mg/m2 i.v. days 1+8 every 3 weeks (= 1 cycle) and T weekly (4 mg/kg loading dose, 2 mg/kg thereafter i.v.) until progression or unacceptable toxicity. Planned sample size was 50, but the study was replaced by a randomised trial at 46 pts, all of them eligible. Primary endpoint was RR, secondary endpoints included TTP, overall survival (OS) and toxicity. Results: From December 2001-July 2004 46 pts were recruited at 4 centers. They received 11 (1–54) cycles (median, range). V dose was reduced due to neutropenia in 7.5% of cycles and for other reasons in 14.5%. V treatment was delayed due to neutropenia in 7.8% of cycles and for other reasons in 4.7% of cycles. Median received V dose intensity was 0,78. Cardiotoxicity: asymptomatic reduction of LVEF > 20% or >10% to below 50%: 8 pts (3 to below 50%). Toxicity grade III-IV (pts): Neutropenia: 11. Infections: 5 (one septic death). Constipation 2. 43 pts have progressed and 32 have died. RR: CR: 9 (20%) PR: 13 (28%) SD 11 (24%) (SD> 6 months 9 (20%)) PD: 10 (22%) NE: 3 (7%). Median duration of response: 18.0 months. Median TTP: 11.0 months (95% confidence interval (95%CI) 7.6–14.4). Median OS: 25.4 months (95%CI 22.7–28.0). After progression 24 received docetaxel, 14 capecitabine, 6 epirubicine, and 11 endocrine therapy. Conclusions: V given twice every 3 weeks and T weekly is a highly active and well-tolerated 1. Line treatment for HER2+MBC. Recruitment into the trial was stopped at 46 pts in favor of a phase III-trial which is ongoing in the Nordic countries comparing V (days 1+8) + T with docetaxel+T every 3 weeks.

No significant financial relationships to disclose.

Comorbidity and survival of Danish breast cancer patients from 1995 to 2005

Comorbid diseases can affect breast cancer prognosis. We conducted a population-based study of Danish women diagnosed with a first primary breast cancer from 1995 to 2005 (n=9300), using hospital discharge registry data to quantify comorbidities by Charlson score. We examined the influence of comorbidities on survival, and quantified their impact on relative mortality rates. The prevalence of patients with a Charlson score='0' fell from 86 to 81%, with an increase in those with Charlson score='1-2' from 13 to 16%, and score='3+' from 1 to 2%. One- and five-year survival for patients with Charlson score='0' and '1-2' was better for those diagnosed in 1998-2000 than in 1995-1997. Overall, patients diagnosed in 2001-2004 (mortality ratio (MR)=0.80, 95% CI=0.68-0.95) and 1998-2000 (MR=0.92, 95% CI=0.78-1.09) had lower 1-year age-adjusted mortality compared to those diagnosed in 1995-1997 (reference period). Patients with Charlson scores '1-2' and '3+' had higher age-adjusted 1-year mortality than those with a Charlson score='0' in each time period (2001-2004: MR('1-2')=1.76, 95% CI=1.35-2.30, and MR('3+')=3.78, 95% CI=2.51-5.68; and 1998-2000: MR('1-2')=1.60, 95% CI=1.36-1.88 and MR('3+')=2.34, 95% CI=1.65-3.33). Similar findings were observed for 5-year age-adjusted mortality. Additional analyses, adjusted for stage, indicated that confounding by stage could not explain these findings. Despite continued improvements in breast cancer survival, we found a trend of poorer survival among breast cancer patients with severe comorbidities even after adjusting for age and stage. Such poorer survival is an important public health concern and can be expected to worsen as the population ages.

Use of postmenopausal hormone replacement therapy and risk of non-Hodgkin's lymphoma: a Danish population-based cohort study

Use of postmenopausal hormone replacement therapy (HRT) has been hypothesised to be associated with a reduced risk of non-Hodgkin's lymphoma (NHL), but the epidemiologic evidence is conflicting. To examine the risk of NHL in HRT users aged 40 and older, we conducted a cohort study in the County of North Jutland, Denmark (population 0.5 million) using data from population-based health registries for the period 1989–2002. We computed age-standardised NHL incidence rates and used Cox regression analysis to compute the relative risk (RR) and corresponding 95% confidence intervals (CI) of NHL among HRT users compared with non-users, adjusting for age and calendar period. The number of prescriptions redeemed (1, 2–4, 5–9, 10–19, or 20 or more prescriptions) was used as a proxy for duration of HRT. We identified 40 NHL cases among HRT users during 179 838 person-years of follow-up and 310 NHL cases among non-users during 1 247 302 person-years of follow-up. The age-standardised incidence rates of NHL were 25.7 per 100 000 among HRT users and 24.2 per 100 000 among non-users, yielding an adjusted RR of 0.99 (95% CI: 0.71–1.39). Our data did not support an association between HRT use and risk of NHL.

Does timing of adjuvant chemotherapy influence the prognosis after early breast cancer? Results of the Danish Breast Cancer Cooperative Group (DBCG)

The purpose of this study was to examine the effect on survival of delaying the start of adjuvant chemotherapy for early breast cancer for up to 3 months after surgery. In the nation-wide clinical trials of the Danish Breast Cancer Cooperative Group, 7501 breast cancer patients received chemotherapy within 3 months of surgery between 1977 and 1999: 352 with classical cyclofosfamide, metotrexate and 5-fluorouracil (CMF); 6065 with CMF i.v. and 1084 with cyclofosfamide, epirubicin and 5-fluorouracil. For the analysis, the time between surgery and the start of chemotherapy was divided into four strata (1–3, 4, 5 and 6–13 weeks). The results show that within the three groups of chemotherapy, there was an even distribution of known prognostic factors across the four strata of initiation of chemotherapy. There was no pattern indicating a benefit from early start of chemotherapy. No significant interactions were found for subgroups of patients with a poorer prognosis (many involved lymph nodes, high-grade malignancies or hormone receptor negative disease). In conclusion, we have found no evidence for a survival benefit due to early initiation of adjuvant chemotherapy within the first 2–3 months after surgery.

Hormone use for menopausal symptoms and risk of breast cancer. A Danish cohort study

Numerous studies and meta-analyses have shown that hormone replacement therapy (HRT) for menopausal symptoms increases the risk of developing breast cancer, estimated to be 2.3% for each year of use. The influence of different oestrogen–progestin regimens has still not been fully evaluated. Using longitudinal data from the population-based prescription database of the county of North Jutland, Denmark, and the Danish Cancer Registry, we examined the risk of developing breast cancer in relation to HRT in a cohort of 78 380 women aged 40–67 years from 1989 to 2002. A total of 1462 cases of breast cancer were identified during a mean follow-up of 10 years. Use of HRT did not increase the risk of breast cancer in women aged 40–49 years. Restricting the cohort to 48 812 women aged 50 years or more at entry, of whom 15 631 were HRT users, we found an increased risk associated with current use of HRT (relative risk 1.61, 95% confidence interval 1.38–1.88). The risk increased with increasing duration of use and decreased with time since last HRT prescription, reaching unity after 5 years. No material risk difference was observed among the various HRT-regimens. This population-based cohort study provides further confirmation that HRT increases the risk of developing breast cancer in women aged 50 years or more.

Time trends and regional differences in registration, stage distribution, surgical management and survival of breast cancer in Denmark

The aim of this study was to analyse time trends, stage at diagnosis, survival and registration of population-based cohorts of breast cancer patients in selected Danish counties (in total 2504) in 1986 and 1996-1997. In 1986, no differences in the extent of disease were observed between the counties. Patients from one county (Funen) had centralised surgery, significantly more lymph nodes removed and a better survival in the multivariate analysis. In 1996-1997, mammographical screening had been implemented in Funen, leading to a significantly better stage distribution, whereas stage remained unchanged in the other counties. In Funen, survival was significantly better than in the other counties in univariate, but not in multivariate analysis. Survival increased significantly with time only in Funen. Inclusion in clinical trials increased over time and the coverage of the database in the Danish Breast Cancer Cooperative Group (DBCG) was high. However, patients not notified in DBCG had, beside older age, also worse stage of disease distribution and less extensive surgery. A difference in survival was observed between the counties. In 1986, this may be explained by a centralised surgical system in one county, whereas in 1996-1997 improvements could be due to an early diagnosis and other as yet unknown factors. The DBCG database cannot be considered as representative of the Danish population of breast cancer patients.

Alcohol, tobacco and breast cancer--collaborative reanalysis of individual data from 53 epidemiological studies, including 58,515 women with breast cancer and 95,067 women without the disease

Alcohol and tobacco consumption are closely correlated and published results on their association with breast cancer have not always allowed adequately for confounding between these exposures. Over 80% of the relevant information worldwide on alcohol and tobacco consumption and breast cancer were collated, checked and analysed centrally. Analyses included 58,515 women with invasive breast cancer and 95,067 controls from 53 studies. Relative risks of breast cancer were estimated, after stratifying by study, age, parity and, where appropriate, women's age when their first child was born and consumption of alcohol and tobacco. The average consumption of alcohol reported by controls from developed countries was 6.0 g per day, i.e. about half a unit/drink of alcohol per day, and was greater in ever-smokers than never-smokers, (8.4 g per day and 5.0 g per day, respectively). Compared with women who reported drinking no alcohol, the relative risk of breast cancer was 1.32 (1.19-1.45, P<0.00001) for an intake of 35-44 g per day alcohol, and 1.46 (1.33-1.61, P<0.00001) for >/=45 g per day alcohol. The relative risk of breast cancer increased by 7.1% (95% CI 5.5-8.7%; P<0.00001) for each additional 10 g per day intake of alcohol, i.e. for each extra unit or drink of alcohol consumed on a daily basis. This increase was the same in ever-smokers and never-smokers (7.1% per 10 g per day, P<0.00001, in each group). By contrast, the relationship between smoking and breast cancer was substantially confounded by the effect of alcohol. When analyses were restricted to 22 255 women with breast cancer and 40 832 controls who reported drinking no alcohol, smoking was not associated with breast cancer (compared to never-smokers, relative risk for ever-smokers=1.03, 95% CI 0.98-1.07, and for current smokers=0.99, 0.92-1.05). The results for alcohol and for tobacco did not vary substantially across studies, study designs, or according to 15 personal characteristics of the women; nor were the findings materially confounded by any of these factors. If the observed relationship for alcohol is causal, these results suggest that about 4% of the breast cancers in developed countries are attributable to alcohol. In developing countries, where alcohol consumption among controls averaged only 0.4 g per day, alcohol would have a negligible effect on the incidence of breast cancer. In conclusion, smoking has little or no independent effect on the risk of developing breast cancer; the effect of alcohol on breast cancer needs to be interpreted in the context of its beneficial effects, in moderation, on cardiovascular disease and its harmful effects on cirrhosis and cancers of the mouth, larynx, oesophagus and liver.

Risk factors for male breast cancer--a case-control study from Scandinavia

We report a population-based case-control study on risk factors for male breast cancer. Data on a broad range of previously suggested risk factors were collected in a set of Scandinavian breast cancer cases and matched controls. Incident cases (n = 282) with histologically verified carcinomas of the breast were identified from notification to the cancer registries of Denmark, Norway and Sweden over a 4-year period 1987-1991 and of these cases, 156 men could be approached and responded. Controls were identified through national central population registers and were matched individually for country, sex and year of birth. Controls with a diagnosis of breast cancer were excluded; 468 of 780 controls responded. Data on risk factors were collected by self-administered questionnaires mailed to the cases between land 2 years after diagnosis and to controls during the same period. The findings were compatible with an increased risk associated with family history of breast cancer (odds ratio (OR) = 3.3, 95% confidence interval (CI) 2.0-5.6), obesity 10 years before diagnosis (OR = 2.1, 95% CI 1.0-4.5) for BMI > 30, diabetes (OR = 2.6, 95% CI 1.3-5.3) and the use of digoxin and methyldopa (OR = 2.0 and 2.1, respectively). The association with family history of breast cancer has been repeated in several studies, while the relation to anthropometric measures has been equivocal. We could not substantiate some associations seen in other studies; namely those with high education, fertility, marital status, testicular injury, liver disease and religion. The detailed questions about gynaecomastia indicated that many cases reported signs of breast cancer as a gynaecomastia. This type of misunderstanding may explain the strong association with gynaecomastia seen in other studies. Several patients died before contact. Thus, risk factors related to a more aggressive male breast cancer or related to high risk of dying (e.g. liver cirrhosis, heavy smoking) may have been missed.

Breast cancer and hormonal contraceptives: further results. Collaborative Group on Hormonal Factors in Breast Cancer

The Collaborative Group on Hormonal Factors in Breast Cancer has brought together and reanalysed the worldwide epidemiological evidence on breast cancer risk and use of hormonal contraceptives. Original data from 54 studies, representing about 90% of the information available on the topic, were collected, checked and analysed centrally. The 54 studies were performed in 26 countries and include a total of 53,297 women with breast cancer and 100,239 women without breast cancer. The studies were varied in their design, setting and timing. Most information came from case-control studies with controls chosen from the general population; most women resided in Europe or North America and most cancers were diagnosed during the 1980s. Overall 41% of the women with breast cancer and 40% of the women without breast cancer had used oral contraceptives at some time; the median age at first use was 26 years, the median duration of use was 3 years, the median year of first use was 1968, the median time since first use was 16 years, and the median time since last use was 9 years. The main findings, summarised elsewhere, are that there is a small increase in the risk of having breast cancer diagnosed in current users of combined oral contraceptives and in women who had stopped use in the past 10 years but that there is no evidence of an increase in the risk more than 10 years after stopping use. In addition, the cancers diagnosed in women who had used oral contraceptives tended to be less advanced clinically than the cancers diagnosed in women who had not used them. Despite the large number of possibilities investigated, few factors appeared to modify the main findings either in recent or in past users. For recent users who began use before age 20 the relative risks are higher than for recent users who began at older ages. For women whose use of oral contraceptives ceased more than 10 years before there was some suggestion of a reduction in breast cancer risk in certain subgroups, with a deficit of tumors that had spread beyond the breast, especially among women who had used preparations containing the highest doses of oestrogen and progestogen. These findings are unexpected and need to be confirmed. Although these data represent most of the epidemiological evidence on the topic to date, there is still insufficient information to comment reliably about the effects of specific types of oestrogen or of progestogen. What evidence there is suggests, however, no major differences in the effects for specific types of oestrogen or of progestogen and that the pattern of risk associated with use of hormonal contraceptives containing progestogens alone may be similar to that observed for preparations containing both oestrogens and progestogens. On the basis of these results, there is little difference between women who have and have not used combined oral contraceptives in terms of the estimated cumulative number of breast cancers diagnosed during the period from starting use up to 20 years after stopping. The cancers diagnosed in women who have used oral contraceptives are, however, less advanced clinically than the cancers diagnosed in never users. Further research is needed to establish whether the associations described here are due to earlier diagnosis of breast cancer in women who have used oral contraceptives, to the biological effects of the hormonal contraceptives or to a combination of both. Little information is as yet available about the effects on breast cancer risk of oral contraceptive use that ceased more than 20 years before and as such data accumulate it will be necessary to re-examine the worldwide evidence.

Hormone therapy in the menopause and breast cancer risk--a review

OBJECTIVES

To evaluate the association between use of hormones in the menopause and breast cancer risk.

METHODS

A qualitative review of reports published between 1970 and 1995.

RESULTS

The risk of breast cancer starts to increase after 5 or more years of hormone use and remains elevated while taking hormones. Use for 10 or more years may be associated with a 30-80% increase in risk. From 2 to 5 years after stopping taking hormones, the risk seems to return to unity. There is no difference in risk between different types of oestrogens and the addition of progestins does not lower the risk.

CONCLUSIONS

Short term use (less than 5 years) seems safe with respect to breast cancer risk, while longer durations of use may be associated with a small, but significant increase in risk.

Epidemiology of breast cancer: the Nordic contribution

In the Nordic countries, breast cancer, is the most common malignant disease among women and the incidence has been increasing steadily for the past 30 years. The age-specific incidence curve of female breast cancer suggests that the menopause has a protective effect. Nordic studies have provided evidence of an increased breast cancer risk in women of low parity, those who have their first child late, and those who have used oral contraceptives and hormone replacement therapy for a long time.

Incidence of female breast cancer in relation to prevalence of risk factors in Denmark

The extent to which changes in prevalence of risk determinants for female breast cancer could explain the temporal variation in incidence was examined using incidence figures from Denmark for the years 1943-1989. Significant increases in incidence were observed for more recent time periods and birth cohorts. Using deviance statistics from Poisson regression measures of variability explained, only a small proportion of the increase in incidence could be accounted for by fertility rates, average age at menarche and exposure to exogenous hormones. Dietary factors, on the other hand, accounted for the greater proportion of the variation observed by time period or birth cohort. In particular, there was a strong positive association of incidence with alcohol consumption and a negative association with carbohydrate intake.

Dietary risk factors for cancer and adenomas of the large intestine. A case-control study within a screening trial in Denmark

The aims of the study were to estimate the importance of dietary habits for colorectal cancers and adenomas. By comparing risk factors among cancer and adenoma patients the adenoma cancer theory was indirectly evaluated. The study was performed as a case-control study within a large screening trial in Denmark. All cancer and adenoma patients diagnosed at the screening were recruited as cases; controls were selected among test negatives after matching for age, sex and time of screening. All those selected except 85, participated in a 7-day dietary recall. Altogether 49 colorectal cancer patients and 172 with adenomas were examined; 362 individuals who were test negatives in the Hemoccult-II screen served as controls. The intake of crude dietary fibres was shown to be associated with reduced risk of cancer as well as adenomas. Neither cancer nor adenoma occurrences were related to total energy intake or body mass. Vitamins E and A were negatively associated with adenoma occurrence.

Adipose tissue fatty acids as biomarkers of dietary exposure in Danish men and women

Adipose tissue fatty acids, it has been proposed, reflect dietary intake. Using data from a validation study preceding a prospective study on diet, cancer, and health in Denmark, we were able to compare fatty acid profiles in adipose tissue biopsies from 86 individuals (23 men and 63 women) aged 40-64 y and dietary intake of fatty acids (as percentage of total fat) assessed by two 7-d weighed-diet records or by a semi-quantitative food frequency questionnaire. Correlation coefficients (Pearson r) between fatty acid concentrations in adipose tissue biopsies (as percentage of total peak area) and dietary intake of fatty acid (percentage of total fat), determined from the diet records for men and women, respectively, were as follows: polyunsaturated fatty acids r = 0.74 and r = 0.46; n - 3 fatty acids of marine origin: eicosapentaenoic acid r = 0.15 and r = 0.61, and docosahexaenoic acid r = 0.47 and r = 0.57. Correlation coefficients obtained by using the food frequency questionnaire were slightly lower for most fatty acids.

Breast cancer in Denmark. Incidence, risk factors, and characteristics of survival

In Denmark, incidence of female breast cancer remained constant from 1943 to around 1960, whereafter a steady increase has occurred, the level today being about 50% higher than in 1960. No equivalent rise has been observed for breast cancer mortality. Influence of hormonal and dietary factors on breast cancer risk and survival was evaluated in a combined population-based case-control and follow-up study, including 2,445 women, aged less than 70 years, diagnosed with breast cancer in Denmark between 1 March 1983 and 31 August 1984, identified from the files of the nation-wide clinical trial of the Danish Breast Cancer Co-operative Group (DBCG) and the Danish Cancer Registry. The control group was an age-stratified random sample of the general female population, selected from the Central Population Register. Data on risk factors were collected by self-administered questionnaires. Clinical and pathological tumour characteristics derived from DBCG. The case-control analysis confirmed an overall increased risk of breast cancer associated with urban residence, high social status, nulliparity, early age at menarche, late age at natural menopause, hormonal replacement therapy, high dietary fat intake, and high alcohol consumption in a subgroup. It failed to detect an association with age at first childbirth, oral contraceptives, smoking, intake of vegetables, tea, coffee, and sweeteners. Survival was determined by tumour size, skin invasion, number of positive lymph nodes, and grade. There was no relation between survival and reproductive or hormonal factors, dietary variables, alcohol consumption, or smoking. However, a complex relationship may exist between survival and body mass index.

Oxidative DNA damage estimated by 8-hydroxydeoxyguanosine excretion in humans: influence of smoking, gender and body mass index

Oxidative DNA damage may be implicated in ageing, carcinogenesis and other degenerative diseases. Oxidative DNA damage can be assessed in humans in vivo from the urinary excretion of the DNA-repair product 8-hydroxydeoxyguanosine (8OHdG). We investigated factors influencing the excretion of 8OHdG in 24 h urine from 83 randomly selected healthy subjects (52 women) aged 40-64 years. For 2 weeks prior to urine collection the subjects kept a weighed diet record. 8OHdG was quantified by an automatic three-dimensional HPLC analysis with electrochemical detection. The 8OHdG excretion was 252 +/- 103 (mean +/- SD) pmol kg body weight/24 h with a range from 78 to 527. Multiple regression analysis identified three factors, smoking, body mass index (BMI) and gender, as significant predictors of the 8OHdG excretion. In 30 smokers the 8OHdG excretion was 320 +/- 99 pmol/kg/24 h opposed to 213 +/- 84 pmol/kg/24 h in 53 non-smokers. According to multiple regression analysis smokers excreted 50% (31-69%; 95% confidence interval) more 8OHdG than non-smokers. In 52 women the 8OHdG excretion was 240 +/- 106 pmol/kg/24 h opposed to 271 +/- 96 pmol/kg/24 h in 31 men. According to the multiple regression analysis men excreted 29% (10-48%) more 8OHdG than women. According to multiple regression analysis the 8OHdG excretion decreased with 4% (2-6%) per increment in BMI measured in kg/m2. The dietary distribution of energy demonstrated no important predictive value with respect to 8OHdG excretion. The intake of the antioxidant vitamins C and E and of vitamin A equivalents, including beta-carotene, was not associated with 8OHdG excretion. The results suggest that smoking increases oxidative DNA damage by approximately 50%. This effect implies potential serious health effects adding to the other well-known health hazards of smoking. The higher 8OHdG excretion in men and lean subjects may be related to a higher rate of metabolism with increased availability of reactive oxygen species. The apparent 7-fold individual variation in oxidative DNA damage carries implications regarding the rate of ageing and the risk of cancer and other degenerative diseases. The excretion of 8OHdG into urine offers a valuable tool for testing such hypotheses in humans.

Influence of individually estimated portion size data on the validity of a semiquantitative food frequency questionnaire

Using data from a Danish dietary validity study, we evaluated the influence of including individually estimated portion size data on the validity of a semiquantitative food frequency questionnaire. A total of 144 subjects, aged 40-64 years were included. Correlation coefficients and classification of subjects into quintiles according to their intake of foods and nutrients were used to compare questionnaire data, with and without individually estimated portion size data, with data obtained by 2 x 7 days weighed diet records. For men, the mean correlation coefficient for food group comparisons was 0.47 when information about individually estimated portion sizes for food items that do not come in natural units was included in the analysis. Using a common average portion size reduced the mean correlation coefficient to 0.45. For women, similar changes were observed (0.36 to 0.35). For nutrients the mean values for the comparison changed from 0.51 to 0.49 and from 0.39 to 0.40 for men and women, respectively. For both men and women the classification into quintiles according to their intake of foods and nutrients showed only minor differences. We conclude that little extra information was gained by including individual portion size information for food items that do not come in natural units. This may reflect that portion sizes are of minor importance compared with frequencies or that the relevant individual portion sizes were not estimated correctly.

Oral contraceptives and breast cancer risk in Denmark

To evaluate the influence of oral contraceptives (OCs) on breast cancer risk, a population-based case-control study was conducted in Denmark. The study population included women aged less than 40 years (203 cases, diagnosed between 1 March 1983 and 31 August 1984, and 212 controls) and women aged 40-59 years (856 cases, diagnosed between 1 March 1983 and 29 February 1984, and 779 controls). Cases were identified from the nationwide clinical trial of the Danish Breast Co-operative Group and the Danish Cancer Registry. The control groups were age-stratified random samples of the general female population. Data on OC use and breast cancer risk factors were collected by self-administered questionnaires. In both age groups, no significant association was detected between breast cancer risk and duration, age at start, latency or recency of OC use. However, the data provided some limited support that OCs containing 50 micrograms or more oestrogen may be more harmful than pills with a lower oestrogen dose.

[P-pills and risk of breast cancer. A review of studies published 1970-1990]

A review of five cohort and 33 case-control studies provides evidence of an increased risk of breast cancer in women aged less than 45 years who were exposed to oral contraceptives for 5-10 years. It is probable that the increased risk is related to oral contraceptive use before the first pregnancy. No association was found between oral contraceptive use and breast cancer risk in women aged 45 years or more.