Wage losses and their effects on financial situation constitute an important adverse consequence of breast cancer in Canada.

Some studies have suggested that insulin-like growth factor (IGF) pathway is related to premenopausal breast density, one of the strongest known breast cancer risk factors. This study was designed specifically to test the hypothesis that higher levels of IGF-I and lower levels of IGF-binding protein (IGFBP)-3 are associated with high mammographic breast density among premenopausal but not among postmenopausal women. A total of 783 premenopausal and 791 postmenopausal healthy women were recruited during screening mammography examinations. Blood samples were collected at the time of mammography, and plasma IGF-I and IGFBP-3 levels were measured by ELISA. Mammographic breast density was estimated using a computerassisted method. Spearman's partial correlation coefficients (r s ) were used to evaluate the associations. Adjusted mean breast density was assessed by joint levels of IGF-I and IGFBP-3 using generalized linear models. Among premenopausal women, high levels of IGF-I and low levels of IGFBP-3 were independently correlated with high breast density (r s = 0.083; P = 0.021 and r s = À0.124; P = 0.0005, respectively). Correlation of IGF-I with breast density was stronger among women in the lowest tertile of IGFBP-3 than among those in the highest tertile of IGFBP-3 (r s = 0.138; P = 0.027 and r s = À0.039; P = 0.530, respectively). In contrast, the correlation of IGFBP-3 with breast density was stronger among women in the highest tertile of IGF-I than among those in the lowest tertile of IGF-I (r s = À0.150; P = 0.016 and r s = À0.008; P = 0.904, respectively). Women in the combined top tertile of IGF-I and bottom tertile of IGFBP-3 had higher mean breast density than those in the combined bottom tertile of IGF-I and top tertile of IGFBP-3 (53.8% versus 40.9%; P = 0.014). No significant association was observed among postmenopausal women. Our findings confirm that IGF-I and IGFBP-3 are associated with breast density among premenopausal women. They provide additional support for the idea that, among premenopausal women, these growth factors may affect breast cancer risk, at least in part, through their influence on breast tissue morphology as reflected on mammogram.

Treatment according to consensus recommendations is associated with improved survival of women with breast cancer in the community. Promoting the adoption of guidelines for treatment is an effective strategy for disease control.

Background: A better understanding of factors that affect breast density, one of the strongest breast cancer risk indicators, may provide important clues about breast cancer etiology and prevention. This study evaluates the association of vitamin D and calcium, from food and/or supplements, to breast density in premenopausal and postmenopausal women separately. Methods: A total of 777 premenopausal and 783 postmenopausal women recruited at two radiology clinics in Quebec City, Canada, in 2001 to 2002, completed a food frequency questionnaire to assess vitamin D and calcium. Breast density from screening mammograms was assessed using a computer-assisted method. Associations between vitamin D or calcium and breast density were evaluated using linear regression models. Adjusted means in breast density were assessed according to the combined daily intakes of the two nutrients using generalized linear models.

Diets with higher vitamin D and calcium contents were found associated with lower mammographic breast density and breast cancer risk in premenopausal women. Because laboratory studies suggest that the actions of vitamin D, calcium, insulin-like growth factor (IGF)-I, and IGF-binding protein-3 (IGFBP-3) on human breast cancer cells are interrelated, we examined whether IGF-I and IGFBP-3 levels could affect the strength of the association of vitamin D and calcium intakes with breast density. Among 771 premenopausal women, breast density was measured by a computer-assisted method, vitamin D and calcium intakes by a food frequency questionnaire, and levels of plasma IGF-I and IGFBP-3 by ELISA methods. Multivariate linear regression models were used to examine the associations and the interactions. The negative associations of vitamin D or calcium intakes with breast density were stronger among women with IGF-I levels above the median (b = À2.8, P = 0.002 and b = À2.5, P = 0.002, respectively) compared with those with IGF-I levels below or equal to the median (b = À0.8, P = 0.38 and b = À1.1, P = 0.21; P interaction = 0.09 and 0.16, respectively). Similar results were observed within levels of IGFBP-3 (P interaction = 0.06 and 0.03, respectively). This is the first study to report that the negative relation of vitamin D and calcium intakes with breast density may be seen primarily among women with high IGF-I or high IGFBP-3 levels. Our findings suggest that the IGF axis should be taken into account when the effects of vitamin D and calcium on breast density (and perhaps breast cancer risk) are examined at least among premenopausal women. (Cancer Res 2006; 66(1): 588-97)

BACKGROUND The goal of this study was to assess variations with age in the management of breast carcinoma and to identify determinants of care received. METHODS A stratified random sample was selected among women age ≥ 50 newly diagnosed with lymph node negative breast carcinoma in Québec in 1988, 1991, and 1993. Information was abstracted from medical charts. Predictors of definitive locoregional treatment (total mastectomy with lymph node dissection or breast‐conserving surgery with both axillary lymph node dissection and radiation therapy) were identified by multiple logistic regression analysis. RESULTS Overall, 1174 patients age ≥ 50 years with breast carcinoma were included. Women age ≥ 70 years were much less likely to receive definitive locoregional treatment compared with women ages 50–69 years (48.7% vs. 83.5%; P < 0.0001). Older women were less likely to undergo surgery with breast preservation (76.7% vs. 86.3%; P < 0.0001), radiation therapy (54.7% vs. 90.5%; P < 0.0001), dissection of the axillary lymph nodes (55.6% vs. 86.3%; P < 0.0001), or chemotherapy (1.2% vs. 13.9%; P < 0.0001), but not treatment with tamoxifen (66.4% vs. 64.7%; P = 0.41). Adjusting for comorbidity and other characteristics related to the disease, the hospital, and the attending physician, age remained a strong determinant of the probability of receiving definitive locoregional treatment (odds ratio [OR], 0.14; 95% confidence interval [95% CI], 0.12–0.18 for women age ≥ 70 years vs. women ages 50–69 years). The same association was observed when women who did not undergo lymph node dissection but who received systemic adjuvant treatment were considered to have received definitive therapy (OR, 0.13; 95% CI, 0.10–0.17) for women age ≥ 70 years vs. women ages 50–69 years). CONCLUSIONS Less aggressive patterns of care are provided to elderly breast carcinoma patients, independent of comorbidity. This could explain, at least in part, the sustained breast carcinoma mortality in this population. Cancer 1999;85:1104–13. © 1999 American Cancer Society.

Assessment of economic burden of breast cancer to patient and family has generally been overlooked in assessing the impact of this disease. We explored economic aspects from the perspective of women and their caregivers. Focus groups were conducted in 3 Quebec cities representing urban and semi-urban settings: 3 with 26 women first treated for non-metastatic breast cancer in the past 18 months, and 3 with 24 primary caregivers. We purposefully selected participants with different characteristics likely to affect the nature or extent of costs. Thematic content analysis was conducted on verbatim transcripts. Costs of breast cancer could be substantial, but were not the most worrisome aspect of the illness during treatments. Some costs were considered unavoidable, others depended on ability to pay. Costs occurred over a long period, with long term impact, and were borne by the whole family and not just the woman. Principal cost sources discussed were those associated with accessing health care, wage losses, reorganization of everyday life, and coping with the disease. This study provided deeper understanding of cost dynamics and the experience of costs among Canadian women with non-metastatic breast cancer, whose treatment and medical follow-up costs are borne through a system of universal, publicly funded health care.

BACKGROUNDTo understand the relation between hospital of initial treatment and the survival of women with breast cancer, the authors investigated the characteristics of the treatment center that were related most to outcome.METHODSThe authors selected women from 5 regions of Quebec, Canada, who were diagnosed with lymph node‐negative breast cancer between 1988 and 1994. Data were collected by chart review, queries to physicians, and linkage with administrative data bases. Overall survival to the end of 1999 was analyzed using the Kaplan–Meier method and Cox proportional hazards models.RESULTSThe study population included 1727 women with a median follow‐up of 6.8 years. The 7‐year survival rate was 82% (95% confidence interval [95%CI], 80–84%). Compared with women who were treated in centers with ≥ 100 new cases per year, the hazard ratio (HR) of death from any cause was 1.80 (95%CI, 1.23–2.63), 1.44 (95%CI, 1.03–2.03), and 1.30 (95%CI, 0.96–1.76) among women who were treated in hospitals with < 25 new cases, 25–49 new cases, and 50–99 new cases per year after adjusting for case mix and characteristics of the attending physician. However, the significance of caseload disappeared after adjusting for the type of hospital. By contrast, women who were treated in centers with either on‐site radiotherapy, research activity, or teaching status had significantly better outcomes, even after adjusting for caseload (HR, 0.68; 95%CI, 0.50–0.92). These associations were independent of primary treatment received, which was a strong determinant of outcome.CONCLUSIONSPrimary treatment of early‐stage breast cancer in larger hospitals was associated with improved survival. This relation was mediated by factors related to proficiency of care, which tended to cluster within institutions. Cancer 2005. © 2005 American Cancer Society.