Prediagnosis reproductive factors and all-cause mortality for women with breast cancer in the breast cancer family registry

Studies have examined the prognostic relevance of reproductive factors before breast cancer diagnosis, but most have been small and their overall findings inconclusive. Associations between reproductive risk factors and all-cause mortality after breast cancer diagnosis were assessed with the use of a population-based cohort of 3,107 women of White European ancestry with invasive breast cancer (1,130 from Melbourne and Sydney, Australia; 1,441 from Ontario, Canada; and 536 from Northern California, United States). During follow-up with a median of 8.5 years, 567 deaths occurred. At recruitment, questionnaire data were collected on oral contraceptive use, number of full-term pregnancies, age at first full-term pregnancy, time from last full-term pregnancy to breast cancer diagnosis, breastfeeding, age at menarche, and menopause and menopausal status at breast cancer diagnosis. Hazard ratios for all-cause mortality were estimated with the use of Cox proportional hazards models with and without adjustment for age at diagnosis, study center, education, and body mass index. Compared with nulliparous women, those who had a child up to 2 years, or between 2 and 5 years, before their breast cancer diagnosis were more likely to die. The unadjusted hazard ratio estimates were 2.75 [95% confidence interval (95% CI), 1.98-3.83; P < 0.001] and 2.20 (95% CI, 1.65-2.94; P < 0.001), respectively, and the adjusted estimates were 2.25 (95% CI, 1.59-3.18; P < 0.001) and 1.82 (95% CI, 1.35-2.46; P < 0.001), respectively. When evaluating the prognosis of women recently diagnosed with breast cancer, the time since last full-term pregnancy should be routinely considered along with other established host and tumor prognostic factors, but consideration of other reproductive factors may not be warranted.

Prognostic effects of 25-hydroxyvitamin D levels in early breast cancer

PURPOSE

Vitamin D has been linked to breast cancer risk, but prognostic effects are unknown. Such effects are biologically plausible given the presence of vitamin D receptors in breast cancer cells, which act as nuclear transcription factors to regulate gene activity.

PATIENTS AND METHODS

The study was conducted in a prospective inception cohort of 512 women with early breast cancer diagnosed 1989 to 1996. Vitamin D levels were measured in stored blood. Clinical, pathologic, and dietary data were accessed to examine prognostic effects of vitamin D.

RESULTS

Mean age was 50.4 years, mean vitamin D was 58.1 +/- 23.4 nmol/L. Vitamin D levels were deficient (< 50 nmol/L) in 37.5% of patients, insufficient (50 to 72 nmol/L) in 38.5% of patients, and sufficient (> 72 nmol/L) in 24.0% of patients. There was little variation in mean vitamin D levels between summer and winter months. Mean follow-up was 11.6 years; 116 women had distant recurrences, and 106 women died. Women with deficient vitamin D levels had an increased risk of distant recurrence (hazard ratio [HR] = 1.94; 95% CI, 1.16 to 3.25) and death (HR = 1.73; 95% CI, 1.05 to 2.86) compared with those with sufficient levels. The association remained after individual adjustment for key tumor and treatment related factors but was attenuated in multivariate analyses (HR = 1.71; 95% CI, 1.02 to 2.86 for distant recurrence; HR = 1.60; 95% CI, 0.96 to 2.64 for death).

CONCLUSION

Vitamin D deficiency may be associated with poor outcomes in breast cancer.

Physical activity, weight control, and breast cancer risk and survival: clinical trial rationale and design considerations

Substantial observational epidemiological evidence exists that physical activity and weight control are associated with decreased risk of postmenopausal breast cancer. Uncertainty remains regarding several aspects of these associations, including the effect of possible confounding factors on these associations. We present the rationale and design for two randomized controlled trials that can help resolve this uncertainty. In a 5-year prevention trial conducted among women at high risk of breast cancer, the primary endpoint would be breast cancer incidence. For a comparable survivorship trial, the primary endpoint would be the disease-free interval and secondary endpoints would be breast cancer recurrence-free interval, second primary breast cancer, and total invasive plus in situ breast cancer. A set of inclusion and exclusion criteria is proposed for both trials. Intervention goals are the same for both trials. Goals for the weight control intervention would be, for women whose body mass index (BMI) is greater than 25 kg/m(2), to lose 10% of body weight and, for women whose BMI is less than or equal to 25 kg/m(2), to avoid weight gain. The goal for the physical activity intervention would be to achieve and maintain regular participation in a moderate-intensity physical activity program for a total of 150-225 minutes over at least 5 days per week. Sample size calculations are based on alternative assumptions about hazard ratio, adherence, follow-up duration, and power and are presented for the primary prevention and survivorship trials. Although both studies could enhance our understanding of breast cancer etiology and benefit public health, practical considerations, including smaller sample size, ease of recruitment, and reduced likelihood of early termination, favor the survivorship trial at this time.

Insulin-lowering effects of metformin in women with early breast cancer

BACKGROUND

Obesity has been associated with poor breast cancer outcomes. Insulin may mediate this effect, interacting with insulin receptors on breast cancer cells. Metformin, a biguanide derivative used in the treatment of diabetes, reduces insulin levels in subjects with type 2 diabetes and other insulin-resistant states. If metformin lowers insulin levels in women with breast cancer, it may also improve breast cancer outcomes.

PATIENTS AND METHODS

We administered metformin (1500 mg per day) to 32 women with early breast cancer whose baseline insulin levels were at least 45 pmol/L to determine its effect on insulin levels.

RESULTS

Twenty-two (69%) women completed the 6-month intervention. Four women (12.5%) dropped out because of gastrointestinal side effects; the others withdrew for reasons not related to toxicity. Completers were similar to noncompleters for all baseline characteristics apart from global health, overall physical condition, overall quality of life, physical function, and social function (HRQOL), which was decreased in noncompleters. Metformin significantly lowered fasting insulin levels by 15.8 pmol/L (22.4%; P=.024) and improved insulin sensitivity by 25.6% (P=.018), total cholesterol by 5.3%, and low-density lipoprotein (LDL) cholesterol by 9.1%. Metformin reduced weight by 1.9 kg (2.5%; P=.01), and it had no significant effects on HRQOL or specific gastrointestinal symptoms (appetite, nausea/vomiting, diarrhea, constipation).

CONCLUSION

Metformin significantly lowers insulin levels, and it improves insulin resistance in nondiabetic women with breast cancer. A phase III randomized trial to evaluate its effects on breast cancer outcomes is recommended.

Family history of breast cancer and all-cause mortality after breast cancer diagnosis in the Breast Cancer Family Registry

Although having a family history of breast cancer is a well established breast cancer risk factor, it is not known whether it influences mortality after breast cancer diagnosis. We studied 4,153 women with first primary incident invasive breast cancer diagnosed between 1991 and 2000, and enrolled in the Breast Cancer Family Registry through population-based sampling in Northern California, USA; Ontario, Canada; and Melbourne and Sydney, Australia. Cases were oversampled for younger age at diagnosis and/or family history of breast cancer. Carriers of germline mutations in BRCA1 or BRCA2 were excluded. Cases and their relatives completed structured questionnaires assessing breast cancer risk factors and family history of cancer. Cases were followed for a median of 6.5 years, during which 725 deaths occurred. Cox proportional hazards regression was used to evaluate associations between family history of breast cancer at the time of diagnosis and risk of all-cause mortality after breast cancer diagnosis, adjusting for established prognostic factors. The hazard ratios for all-cause mortality were 0.98 (95% confidence interval [CI] = 0.84-1.15) for having at least one first- or second-degree relative with breast cancer, and 0.85 (95% CI = 0.70-1.02) for having at least one first-degree relative with breast cancer, compared with having no such family history. Estimates did not vary appreciably when stratified by case or tumor characteristics. In conclusion, family history of breast cancer is not associated with all-cause mortality after breast cancer diagnosis for women without a known germline mutation in BRCA1 or BRCA2. Therefore, clinical management should not depend on family history of breast cancer.

Identification of cancer care and protocol characteristics associated with recruitment in breast cancer clinical trials

PURPOSE

It is estimated that only 5% of patients with cancer participate in a clinical trial. Barriers to participation may relate to available protocols, physicians, and patients, but few data exist on barriers related to cancer care environments and protocol characteristics.

METHODS

The primary objective was to identify characteristics of cancer care environments and clinical trial protocols associated with a low recruitment into breast cancer clinical trials. Secondary objectives were to determine yearly recruitment fraction onto clinical trials from 1997 to 2002 in Ontario, Canada, and to compare recruitment fraction among years. Questionnaires were sent to hospitals requesting characteristics of cancer care environments and to cooperative groups/pharmaceutical companies for information on protocols and the number of patients recruited per hospital/year. Poisson regression was used to estimate the recruitment fraction.

RESULTS

Questionnaire completion rate varied between 69% and 100%. Recruitment fraction varied between 5.4% and 8.5% according to year. More than 30% of patients were diagnosed in hospitals with no available trials. In multivariate analysis, the following characteristics were associated with recruitment: use of placebo versus not (relative risk [RR] = 0.80; P = .05), nonmetastatic versus metastatic trial (RR = 2.80; P < .01), and for nonmetastatic trials, protocol allowing an interval of 12 weeks or longer versus less than 12 weeks (from diagnosis, surgery, or end of therapy) before enrollment (RR = 1.36; P < .01).

CONCLUSION

Allowable interval of 12 weeks or longer to randomly assign patients in clinical trials could help recruitment. In our study, absence of an available clinical trial represented the largest barrier to recruitment.

Health-related quality of life measurement in symptom management trials

There is increasing support for the incorporation of patient-reported outcomes (PROs) into clinical trials in cancer. While the need for inclusion of measures of target symptoms in symptom management trials is clear, arguments can also be made for measurement of a broader range of symptoms, for evaluation of symptom burden, and for evaluation of health-related quality of life (HRQOL) in these trials. What is key to their inclusion is a priori selection of instruments, provision of a theoretic basis for inclusion of instruments, and a clearly described plan of analysis. The federal Food and Drug Administration (FDA) has provided guidance regarding the use of PROs (symptom and HRQOL measures) to support treatment benefit claims in product labeling. Moving forward, research is needed to address methodological issues raised by the FDA and to increase understanding of relationships among symptoms, symptom clusters, HRQOL, and other outcome measures.

Serum lipids and outcome of early-stage breast cancer: results of a prospective cohort study

PURPOSE

The prognosis of women with early-stage breast cancer is influenced by insulin and body mass index (BMI). High levels of serum insulin and obesity often coexist with dyslipidemia in the insulin resistance syndrome (IRS), but the contribution of lipids to breast cancer outcome is unclear. Here, we examine whether serum levels of total cholesterol (TC) and triglycerides (TG) influence breast cancer outcome.

PATIENTS AND METHODS

A cohort of 520 women without known hyperlipidemia or diabetes, with stage T1-T3, N0-N1, M0 breast cancer, was assembled from July 1989 to June 1996. Fasting blood was collected at baseline. Subjects were followed prospectively, for recurrence (local, regional, distant) and death. Cox models were used to calculate the prognostic effect of TC and TG levels. Two-sided significance levels were set at 0.025.

RESULTS

TC was correlated with age (Spearman's r = 0.44) and low tumor grade (p = 0.01), while TG was correlated with insulin (r = 0.43) and BMI (r = 0.45). At a median follow-up of 8.7 years, TC and TG were not associated with breast cancer recurrence or death before of after adjustment for age, tumor-related variables, BMI or fasting insulin levels. In multivariate analysis adjusting for age, tumor-related variables and BMI, a trend towards an adverse effect of TC on disease recurrence was seen (HR recurrence = 1.62 for the 4th versus. 1st quartile, 2-sided p = 0.03).

CONCLUSIONS

Fasting TG was not associated with outcome. A trend towards risk of recurrence was seen with higher TC in multivariate analysis. This potential association should be explored in future studies.

The impact of diabetes on survival following breast cancer

PURPOSE

It has been suggested that type 2 diabetes may affect breast cancer prognosis, possibly due to increased diabetes-related comorbidity, or direct effects of insulin resistance and/or hyperinsulinemia. The purpose of this study was to examine the impact of diabetes on survival following breast cancer.

METHODS

Using population-based health databases from Ontario, Canada, this retrospective cohort study compared deaths between women with breast cancer aged 55-79 years with diabetes and without diabetes. Women were followed for all cause mortality from breast cancer diagnosis until March 31st 2006.

RESULTS

Of the 6,107 women with breast cancer, 1,011 had diabetes and 5,096 did not have diabetes. Women with diabetes were slightly older, were more likely to reside in a lower income neighborhood, and had greater comorbidity compared to women without diabetes. After a mean follow-up of 5.0 years and adjustment for age, prior mammograms and other covariates, mortality following breast cancer was significantly higher among women with versus without diabetes (hazard ratio, HR 1.39, 95% confidence interval, CI 1.22-1.59, P < 0.0001). The effect of diabetes on mortality was comparable to that seen in women with diabetes without breast cancer over a 7-year follow-up.

CONCLUSION

This study found that diabetes was associated with a close to 40% increase in mortality within the first 5 years following breast cancer, which was similar to that seen in women with diabetes without breast cancer. These findings suggest that early survival following breast cancer is reduced in women with diabetes, possibly due to diabetes-related causes.

Polymorphisms cMyc-N11S and p27-V109G and breast cancer risk and prognosis

BACKGROUND

cMyc and p27 are key genes implicated in carcinogenesis. Whether polymorphisms in these genes affect breast cancer risk or prognosis is still unclear. In this study, we focus on a rare non-synonymous polymorphism in cMyc (N11S) and a common polymorphism in p27 (V109G) and determine their role in risk and prognosis using data collected from the Ontario Breast Cancer Family Registry.

METHODS

Risk factor data was collected at baseline on a large group of women (cases = 1,115 and population-based controls = 710) and clinical data (including treatment and follow-up) were collected prospectively by periodic review of medical records for a subset of cases (N = 967) for nearly a decade. A centralized pathology review was conducted. Unconditional logistic regression was used to determine the association of polymorphisms with breast cancer risk and the Cox proportional hazards model was used to determine their association with survival.

RESULTS

Our results suggest that while cMyc-N11S can be considered a putatively functional polymorphism located in the N-terminal domain, it is not associated with risk, tumor characteristics or survival. The p27-G109 allele was associated with a modest protective effect in adjusted analyses and higher T stage. We found no evidence to suggest that p27-V109G alone or in combination with cMyc-N11S was associated with survival. Age at onset and first-degree family history of breast or ovarian cancer did not significantly modify the association of these polymorphisms with breast cancer risk.

CONCLUSION

Further work is recommended to understand the potential functional role of these specific non-synonymous amino acid changes and a larger, more comprehensive investigation of genetic variation in these genes (e.g., using a tagSNP approach) in combination with other relevant genes is needed as well as consideration for treatment effects when assessing their potential role in prognosis.

Responsiveness to change to change due to supportive-expressive group therapy, improvement in mood and disease progression in women with metastatic breast cancer

OBJECTIVE

To compare the responsiveness of six questionnaires using three hypotheses of change: (i) change due to supportive-expressive group therapy (SEGT), (ii) improved mood defined as a small effect size (.2) on Profile of Mood States (POMS) Total Mood Disturbance score and (iii) progression of disease.

METHOD

Data from the "Breast Expressive-Supportive Therapy" study, a multicentre randomized controlled trial of change due to SEGT versus standard of care in women with metastatic breast cancer were used. Questionnaires studied were: POMS, Impact of Event Scale, Psychosocial Adjustment to Illness Scale (PAIS), EORTC QLQ-C30, Mental Adjustment to Cancer and a Pain visual analog scale (VAS). Responsiveness to change was evaluated using the standardized response mean. POMS was used as the standard.

RESULTS

POMS was the most responsive questionnaire to change due to SEGT. Questionnaires measuring psychosocial attributes were responsive to improvement in mood. EORTC QLQ-C30, PAIS, PAIN VAS and MAC were the most responsive to disease progression. More responsive questionnaires were associated with the smallest sample size required to detect an effect.

CONCLUSIONS

Responsiveness to change is context specific. The POMS was the most responsive questionnaire to psychosocial therapy.

Insulin receptor is an independent predictor of a favorable outcome in early stage breast cancer

Fasting insulin is related to outcome in early breast cancer. We evaluated the expression of insulin receptor (IR) and its prognostic significance in patients with early stage breast cancer. Tumors from 191 patients with T1-3, N0-1, M0 breast cancer who were enrolled at a single center of a multicenter cohort study were used to construct microarrays with subsequent immunohistochemical evaluation of IR, IGF-IR, ER, PgR and HER2/neu. Correlation of biomarker expression with traditional prognostic factors, serum biochemistry (notably insulin) and clinical outcome was assessed. IR was strongly positive (Allred score = 8) in 54% of tumors. High IR expression significantly correlated with favorable prognostic markers (low tumor grade, lymph node negativity and progesterone receptor positivity) but not with fasting levels of circulating insulin. At a median follow-up of 9.1 years, high vs. low IR expression (an Allred score of 8 vs. 0-7) was associated with statistically significant improved distant disease-free survival (multivariate hazard ratio (HR) = 0.4; P = 0.027) and overall survival (multivariate HR = 0.26; P = 0.005). IR is highly expressed in the majority of early stage breast cancers but this expression is not clearly down-regulated in the presence of high insulin levels. Furthermore, high expression of IR is independently and significantly associated with more favorable clinical outcomes. Follow-up intervention research is recommended.

Three methods for minimally important difference: no relationship was found with the net proportion of patients improving

OBJECTIVE

To determine the impact on a responder type analysis of using three published methods to obtain the minimally important difference (MID) on the conclusion of a randomized controlled trial (RCT).

STUDY DESIGN AND SETTING

Using data from an RCT of supportive-expressive group therapy (SEGT-intervention) vs. standard care (control) in women with metastatic breast cancer, we measured individual responsiveness to change according to three levels of predefined MID (0.2 SD, 0.5 SD, and 1 standard error of measurement) of the following six validated questionnaires: Profile of Mood States, Impact of Event Scale, Psychosocial Adjustment to Illness Scale, EORTC Quality-of-Life Questionnaire Core-30, Mental Adjustment to Cancer, and a pain visual analog scale. The proportion of women improved by SEGT and the number needed to treat according to three levels of MID were calculated.

RESULTS

There was no consistent difference in the net proportion of women improving with the SEGT vs. control arm according to the three different levels of MID.

CONCLUSION

The choice between different levels of distribution-based MID did not make an important difference in the net proportion of women improving with the SEGT. Future research should compare MID derived from clinical anchors, in particular patient opinions.

Influence of young age at diagnosis and family history of breast or ovarian cancer on breast cancer outcomes in a population-based cohort study

PURPOSE

The objective of this study was to examine the association of: (i) diagnosis at age </=35, (ii) first-degree family history of breast or ovarian cancer (BOC) and (iii) a research based definition of genetic risk, with tumor characteristics, treatment and survival in breast cancer (BC).

PATIENTS AND METHODS

Consenting female participants in the population-based Ontario Familial Breast Cancer Registry diagnosed with primary invasive BC between 1996 and 1998 were followed prospectively until 2005.

RESULTS

Among 967 women, 105 were </=35 years old at diagnosis and 686 were classified as genetic risk cases, including 349 with a first-degree family history. Individuals diagnosed at age </=35 were more likely to self-detect tumors, to present with inflammatory BC, to have invasive ductal carcinoma of no special type, high T stage, and tumors with lymphovascular invasion (LVI), high grade and negative estrogen receptors. Younger women were more likely to receive chemotherapy and less likely to receive hormonal therapy. Diagnosis </=35 years old was associated with significantly reduced distant recurrence free survival, an effect that did not persist after adjustment for tumor and treatment related variables. Poor outcomes were restricted to younger women with hormone responsive BC. Family history was associated with increased rates of mammographic detection of BC, lower tumor stage and less frequent inflammatory BC, but had no association with BC outcomes.

CONCLUSION

Women diagnosed with BC at age </=35 have more aggressive tumors; these adverse tumor characteristics, rather than age, lead to poor outcomes. Family history was not associated with survival.