Hege Wang

A Basal Epithelial Phenotype Is More Frequent in Interval Breast Cancers Compared with Screen Detected Tumors

Interval breast cancer reduce the effectiveness of mammography screening programs. We studied 95 interval cancers, diagnosed during 1996 to 2001 as part of the population-based Norwegian Breast Cancer Screening Program. These cases were matched on size (±2.0 mm) to 95 screen-detected breast cancers, and the tumors were compared by immunohistochemical methods using tissue microarrays. Patients with interval cancers were more likely to be younger [odds ratio (OR), 4.7; P = 0.0001], to have dense breasts (OR, 3.4; P = 0.004), and to have estrogen receptor–negative tumors (OR, 2.6, P = 0.01), and p53 expression was more frequent (OR, 4.0; P = 0.001). Notably, interval cancers were more likely to have a basal epithelial phenotype, in that expression of cytokeratin 5/6 (OR, 2.3; P = 0.04) and P-cadherin (OR, 2.5; P = 0.04) was more frequent in interval cases than in size-matched, screen-detected tumors. In a logistic regression model, p53 expression, age, and breast density were independent predictors of interval cancers. Our data suggest that breast cancers with a basal epithelial phenotype are more likely than nonbasal breast cancers to present between regular mammograms.

Mammography screening in Norway: results from the first screening round in four counties and cost-effectiveness of a modeled nationwide screening.

AbstractObjective: To evaluate whether the results of the first screening round in the Norwegian Breast Cancer Screening Program predict future mortality reduction and to explore the cost-effectiveness of the program. Methods: The results of surrogate measures were calculated and compared with the targets. A cost-effectiveness analysis was performed assuming a nationwide program starting in 1996 with an attendance rate of 80% and a mortality reduction of 30%. Results: The attendance rate was 79.5% and the detection rate was 0.67%. The proportion of invasive tumors smaller than 15 mm was 53.1%, and 21.7% of the patients who underwent axillary surgery had lymphatic metastasis. The C/E ratios were found to be 3750 US dollars (USD) per year of life saved and 86,045 USD per life saved. Conclusion: The results of the first screening round will lead to a mortality reduction of at least 30%. The cost-effectiveness analysis shows that it is possible to run a highly cost-efficient screening program in Norway.

Interval cancers in the Norwegian breast cancer screening program: Frequency, characteristics and use of HRT

Breast cancers diagnosed between screening examinations among women who attend a breast cancer screening program are defined as interval cancers. The Norwegian Breast Cancer Screening Program started as a pilot project in 1996, and data from the first 2‐year interval are available. Our study quantifies interval cancers in the pilot project and explores characteristics and factors that may be associated with interval cancer. Interval cancers in the screening population were identified through the Cancer Registry of Norway. The frequency of invasive interval cancer was calculated as cases per 10,000 screened and as observed/expected ratio. Characteristics of the interval cancers were compared to screening‐detected and clinical cancers. Breast density was assessed in a blinded review of 3 categories of screening mammograms. Information on hormone replacement therapy (HRT) use was collected from a questionnaire. The frequency of invasive interval cancers was 18.2 (15.9–20.7) per 10,000 screened and the observed/expected ratio was 0.49 (0.43–0.56). The frequency in the second year of the interval was higher than reported from other programs. The median tumor size of the interval cancers was 19.5 mm and 44.0% of the patients had affected axillary lymph nodes. The interval cancer cases had higher proportions of dense breasts and reported use of HRT compared to screen normal and screening‐detected cases. The reported frequency of interval cancers is similar to comparable programs. The interval cancers differed significantly from the cancers detected in the first screening round and were more similar to clinical cancers. Interval cancer was associated with dense breasts and use of HRT. Screening programs must keep these associations in focus.

The Norwegian Breast Cancer Screening Program: re-attendance related to the women's experiences, intentions and previous screening result

Objective: To survey factors of importance for attendance in the Norwegian Breast Cancer Screening Program (NBCSP). Methods: Simple forced choice questionnaires were sent to 1221 women, in four categories: not attended, screened negative, false positive, and breast cancer cases. The response rate was 80.7%. Results: Women who were invited to the NBCSP reported positive opinions about being invited and the provided information. This response was independent of attendance and screening result. An experience of pain during screening examination was reported in the same proportion among women who were screened negative and false positive (p = 0.27). Unsatisfactory care was reported in a significantly lower rate among women who were screened negative, compared to the false positive (p = 0.02) and breast cancer cases (p < 0.01). Re-attendance was significantly higher among women who were screened negative (91.8%), compared to the false positive (83.9%, p < 0.01). Experienced pain seemed to influence re-attendance among the false positive, while care seemed to influence re-attendance among women who were screened negative. Intention to re-attend was significantly associated with the rate of re-attendance (p < 0.01) and it was the only significant predictor for re-attendance (OR = 5.4, 95% CI: 1.8–16.7) in a multiple logistic regression analysis with intention, age, experienced pain, experienced care and waiting time included in the model. Age did not have much influence on results. Conclusion: Women, who were invited to the NBCSP, reported positive opinions about the program. Re-attendance was related to previous screening results, partly by, experienced pain and care.

Do the results of the process indicators in the Norwegian Breast Cancer Screening Program predict future mortality reduction from breast cancer

Continuous emphases of quality control are required to achieve reduction in mortality from breast cancer as a consequence of breast cancer screening. Results of the process indicators in the first 6 years in 4 counties in the Norwegian Breast Cancer Screening Program are evaluated and will be presented. Data from women who had their initial (n=173 402) and subsequent (n=220 058) screening provide the basis for the analysis. The breast cancer detection ratio was 3.2 the expected incidence (based on the incidence before the screening started, 1991–1995) among the initially screened women, decreasing to 2.3 among the subsequently screened. The ratio of interval cancer among the initially screened was 0.25 and 0.72 of the expected incidence, 0–12 and 13–23 months after screening, respectively. For those subsequently screened the proportions were 0.22 and 0.64, respectively. More than 50% of the invasive tumors were less than 15 mm in size, and more than 75% were lymph node negative, among both the initially and subsequently screened. The process indicators achieved in the NBCSP are promising as regards future mortality reduction. The incidence of interval cancer 13–24 months after screening is higher than recommended in the European guidelines.

Breast cancer incidence and mortality in the Nordic capitals, 1970-1998. Trends related to mammography screening programmes.

The aim of the present study was to relate the time trends in breast cancer incidence and mortality to the introduction of mammography screening in the Nordic capitals. Helsinki offered screening to women aged 50–59 starting in 1986. The other three capitals offered screening to women aged 50–69 starting in 1989 in Stockholm, 1991 in Copenhagen, and 1996 in Oslo. Prevalence peaks in breast cancer incidence depended on the age groups covered by the screening, the length of the implementation of screening, and the extent of background opportunistic screening. No mortality reduction following the introduction of screening was visible after seven to 12 years of screening in any of the three capitals where significant effects of the screening on the breast cancer mortality had already been demonstrated by using other analytical methods for the evaluation. No visible effect on mortality reduction was expected in Oslo due to too short an observation period. The study showed that the population-based breast cancer mortality trend is too crude a measure to detect the effect of screening on breast cancer mortality during the first years after the start of a programme.

Logistics of Referral, Diagnostic Assessment and Treatment of Patients with Breast Symptoms and Signs

Background and Aims: The logistics of diagnosis and treatment in a hospital with slightly above 400 new cases of breast cancer per year is analysed. Materials and Methods: The patient flow from referral, through the diagnostic procedures and through surgical treatment is described. Results and Conclusions: The basic principle of the diagnostic assessment is the triple diagnostic procedure including mammography supplemented by ultrasonography, fine needle aspiration cytology and clinical examination. The radiologist and pathologist are working together in the breast diagnostic centre and are thus able to give a “single visit diagnosis” in most cases. The surgeon sees the patient either the same day or the next. A “consensus meeting” held each week with representatives for all specialities present has an important function in quality assurance and education. If one or more of the triple diagnostic components reach conclusion level “suspicious lesion”, surgery is indicated. In hospital management is based on day surgery for all biopsies, wide excisions with or without sentinel node and some ablatio simplex mammae. For wide excision and ablation with complete axillary node clearance, the patients are transferred from the day surgery unit to a patient hotel after 3–4 hours of observation and stay till the drain can be removed. Only in rare case of high cardiopulmonary risk, beds in ordinary wards are used. This is a highly cost efficient logistic saving the hospital approximately 400 000 EUR a year compared to ordinary in hospital treatment.

Ductal Carcinoma In Situ of the Breast: A Review of Diagnosis, Treatment and Outcome in a Hospital-based Norwegian Series

Between 1980 and 1994, 71 women with histologically proven ductal carcinoma in situ (DCIS) were diagnosed at Ullevål Hospital; bilateral tumours were found in two patients. Surgical treatment was mastectomy (42 lesions) or local excision (31 lesions). Median follow-up time was 7.2 years. Ten patients experienced a local recurrence, seven of which were invasive carcinomas. The actuarial 5-year local recurrence rate was 22% after local excision. A multivariate analysis found that tumour size was the only factor that predicted local recurrence after local excision. An analysis of relative survival in a nation-wide material of 832 DCIS patients in the period 1980 to 1994 demonstrates that relative survival after a DCIS diagnosis is almost 100%, irrespective of surgical treatment of the initial lesion.Between 1980 and 1994, 71 women with histologically proven ductal carcinoma in situ (DCIS) were diagnosed at Ullevål Hospital; bilateral tumours were found in two patients. Surgical treatment was mastectomy (42 lesions) or local excision (31 lesions). Median follow-up time was 7.2 years. Ten patients experienced a local recurrence, seven of which were invasive carcinomas. The actuarial 5-year local recurrence rate was 22% after local excision. A multivariate analysis found that tumour size was the only factor that predicted local recurrence after local excision. An analysis of relative survival in a nation-wide material of 832 DCIS patients in the period 1980 to 1994 demonstrates that relative survival after a DCIS diagnosis is almost 100%, irrespective of surgical treatment of the initial lesion.