Menopausal hormone therapy and risk of clinical breast cancer subtypes

Prognostic impact of tumor-specific insulin-like growth factor binding protein 7 (IGFBP7) levels in breast cancer: a prospective cohort study

The prognostic impact of insulin-like growth factor binding protein 7 (IGFBP7) in breast cancer is unclear. Host factors, including lifestyle, anthropometry and metabolic profile, might influence tumor-specific IGFBP7. This study aimed to investigate whether IGFBP7 levels and messenger ribonucleic acid (mRNA) expression are associated with the patient and tumor characteristics and prognosis in breast cancer. Patients with primary breast cancer in Lund, Sweden, were included preoperatively in the study between 2002 and 2012 (n = 1018). Tumor-specific IGFBP7 protein levels were evaluated with immunohistochemistry using tissue microarrays in tumors from 878 patients. IGFBP7 mRNA expression and its corresponding clinical data were obtained from The Cancer Genome Atlas and analyzed for 809 patients. Tumor-specific IGFBP7 protein levels were categorized based on Histo 300 scores into IGFBP7^low (6.2%), IGFBP7^intermediate (75.7%) and IGFBP7^high (18.1%). Both low IGFBP7 protein levels and mRNA expression were associated with less aggressive tumor characteristics. Overall, IGFBP7^low conferred low recurrence risk. The prognostic impact of IGFBP7^high varied according to any alcohol consumption and tamoxifen treatment. IGFBP7^high was associated with low recurrence risk in alcohol consumers but high recurrence risk in alcohol abstainers (P_interaction= 0.039). Moreover, the combination of IGFBP7^high and estrogen receptor-positive tumors was associated with low recurrence risk only in tamoxifen-treated patients (P_interaction= 0.029). To conclude, IGFBP7^low might be a good, independent prognosticator in breast cancer. The prognostic impact of IGFBP7^high depends on host factors and treatment. IGFBP7 merits further investigation to confirm whether it could be a suitable biomarker for treatment selection.

Prognostic Impact of Menopausal Hormone Therapy in Breast Cancer Differs According to Tumor Characteristics and Treatment

This study investigated how a history of menopausal hormone therapy (MHT) impacts clinical outcomes overall and in different subgroups of breast cancer patients. The study included 814 primary breast cancer patients aged ≥50 years in Sweden (2002–2012) with follow-up until 2016. Associations between patient- and tumor characteristics, recurrences, and overall survival were analyzed in relation to MHT. After a median follow-up of 7 years, 119 recurrences, and 111 deaths occurred. Ever MHT (n = 433, 53.2%) was associated with a lower BMI, frequency of alcohol abstinence, and histological grade, higher frequency of oral contraceptive use, and lobular cancer. Overall, MHT was not associated with prognosis, but there were significant effect modifications by estrogen receptor (ER) status, node status, main histological type, and aromatase inhibitor (AI) treatment on recurrence-risk (all P_interactions≤ 0.017). MHT conferred an increased recurrence-risk in patients with ER- tumors, adjusted Hazard Ratio (HR_adj) 3.99 (95% Confidence Interval (CI) 1.40–11.33), in node-negative patients HR_adj 1.88 (95% CI 1.11–3.17), and in non-AI-treated patients HR_adj 1.81 (95% CI 1.01–3.24), but decreased recurrence-risk in AI-treated patients HR_adj 0.46 (95% CI 0.25–0.84) and in patients with lobular cancer HR_adj 0.15 (95% CI 0.04–0.64). MHT was associated with lower risk of death in node-positive patients HR_adj of 0.48 (95% CI 0.27–0.86) and in AI-treated patients HR_adj of 0.41 (95% CI 0.22–0.77), but not in other patients (both P_interactions≤ 0.027). A history of MHT may have prognostic value for certain subgroups of breast cancer patients such as AI-treated or node-negative patients.

Prospectively measured thyroid hormones and thyroid peroxidase antibodies in relation to risk of different breast cancer subgroups: a Malmö Diet and Cancer Study

PURPOSE

Thyroid hormone level has been positively associated with breast cancer risk and with breast cancer cell proliferation and growth. Although breast cancer is a heterogeneous disease, this is the first study assessing pre-diagnostic levels of free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), and thyroid peroxidase antibodies (TPO-Ab) in relation to breast cancer subgroups and aggressiveness.

METHODS

The Malmö Diet and Cancer Study collected blood samples from 17,035 women between 1991 and 1996. Free T3, free T4, TSH, and TPO-Ab were analyzed in 676 incident breast cancer cases and 680 controls. Breast tumors were classified according to tumor size, axillary lymph node involvement, histological grade, histological type, hormone receptor status (ER, PgR), as well as Ki67, cyclin D1, and p27. Odds ratios of different breast cancer subgroups were calculated using a logistic regression analysis adjusted for potential confounders.

RESULTS

High fT4 was associated with a statistically significant higher risk of overall breast cancer, small, grade I, ER-positive, PgR-positive, and cyclin D1 low tumors. The associations for ER and PgR were verified in a heterogeneity analysis. Low TPO-Ab was associated with a higher risk of overall breast cancer, ductal, large, ER-positive, PgR-positive, cyclin D1 low, and p27 high tumors. The heterogeneity analysis verified the association for tumor size. Free T3 was not associated with overall breast cancer risk, but in the heterogeneity analysis, high fT3 was associated with tumor size and expression of p27. There were no strong associations between TSH and overall breast cancer risk or any tumor subgroup.

CONCLUSION

High pre-diagnostic fT4 levels and low pre-diagnostic TPO-Ab levels were associated with an increased risk of breast cancer. This increase was mainly limited to a higher incidence rate of less aggressive breast cancer subgroups.

Lobular breast cancer: incidence and genetic and non-genetic risk factors

While most invasive breast cancers consist of carcinomas of the ductal type, about 10% are invasive lobular carcinomas. Invasive lobular and ductal carcinomas differ with respect to risk factors. Invasive lobular carcinoma is more strongly associated with exposure to female hormones, and therefore its incidence is more subject to variation. This is illustrated by US figures during the 1987 to 2004 period: after 12 years of increases, breast cancer incidence declined steadily from 1999 to 2004, reflecting among other causes the decreasing use of menopausal hormone therapy, and these variations were stronger for invasive lobular than for invasive ductal carcinoma. Similarly, invasive lobular carcinoma is more strongly associated with early menarche, late menopause and late age at first birth. As for genetic risk factors, four high-penetrance genes are tested in clinical practice when genetic susceptibility to breast cancer is suspected, BRCA1, BRCA2, TP53 and CDH1. Germline mutations in BRCA1 and TP53 are predominantly associated with invasive ductal carcinoma, while BRCA2 mutations are associated with both ductal and lobular cancers. CDH1, the gene coding for the E-cadherin adhesion protein, is of special interest as mutations are associated with invasive lobular carcinoma, but never with ductal carcinoma. It was initially known as the main susceptibility gene for gastric cancer of the diffuse type, but the excess of breast cancers of the lobular type in CDH1 families led researchers to identify it also as a susceptibility gene for invasive lobular carcinoma. The risk of invasive lobular carcinoma is high in female mutation carriers, as about 50% are expected to develop the disease. Carriers must therefore undergo intensive breast cancer screening, with, for example, yearly magnetic resonance imaging and mammogram starting at age 30 years.

[Invasive breast cancer: the current WHO classification]

The World Health Organization (WHO) classification of tumors of the breast defines the international standards for tumor categorization and nomenclature. The fourth edition, published in 2012, provides an update on the current knowledge concerning the classification, immunohistology profile, differential diagnosis and genetics of these lesions. Compared to the previous edition, some terms have been modified, some entities were reclassified and some current molecular data have been added. This article focuses on invasive carcinomas. Definitions for histological diagnosis are supplemented by clinical, macroscopic and molecular characteristics as well as prognostic and predictive features.

Use of menopausal hormone therapy and risk of ductal and lobular breast cancer among women 55-74 years of age

The Women's Health Initiative (WHI) randomized trials found that use of combined estrogen and progestin menopausal hormone therapy (CHT) increases breast cancer risk, but use of unopposed estrogen hormone therapy (EHT) does not. However, several questions regarding the impact of hormone use on risk of different types of breast cancer and what thresholds of use confer elevations in risk remain. We conducted a population-based case-control study among women 55-74 years of age to assess the association between menopausal hormone use and risk of invasive ductal and invasive lobular breast carcinomas. Associations were evaluated using polytomous logistic regression and analyses included 880 ductal cases, 1,027 lobular cases, and 856 controls. Current EHT and CHT use were associated with 1.6-fold [95 % confidence interval (CI): 1.1-2.2] and 2.3-fold (95 % CI: 1.7-3.2) increased risks of lobular breast cancer, respectively, but neither was associated with risk of ductal cancer. Lobular cancer risk was increased after 9 years of EHT use, but after only 3 years of CHT use. Evidence across more than a dozen studies indicates that lobular carcinoma is the type of breast cancer most strongly influenced by menopausal hormones. Here, we characterize what thresholds of duration of use of both EHT and CHT that confer elevations in risk. Despite the rapid decline in hormone therapy use the WHI results were published, study of the hazards associated with these medications remains relevant given the estimated 38 million hormone therapy prescriptions that are still filled in the United States annually.

Reproductive risk factors and oestrogen/progesterone receptor-negative breast cancer in the Breast Cancer Family Registry

BACKGROUND

Oestrogen receptor (ER)- and progesterone receptor (PR)-negative (ER-PR-) breast cancer is associated with poorer prognosis compared with other breast cancer subtypes. High parity has been associated with an increased risk of ER-PR- cancer, but emerging evidence suggests that breastfeeding may reduce this risk. Whether this potential breastfeeding benefit extends to women at high risk of breast cancer remains critical to understand for prevention.

METHODS

Using population-based ascertained cases (n=4011) and controls (2997) from the Breast Cancer Family Registry, we examined reproductive risk factors in relation to ER and PR status.

RESULTS

High parity (≥3 live births) without breastfeeding was positively associated only with ER-PR- tumours (odds ratio (OR)=1.57, 95% confidence interval (CI), 1.10-2.24); there was no association with parity in women who breastfed (OR=0.93, 95% CI 0.71-1.22). Across all race/ethnicities, associations for ER-PR- cancer were higher among women who did not breastfeed than among women who did. Oral contraceptive (OC) use before 1975 was associated with an increased risk of ER-PR- cancer only (OR=1.32, 95% CI 1.04-1.67). For women who began OC use in 1975 or later there was no increased risk.

CONCLUSIONS

Our findings support that there are modifiable factors for ER-PR- breast cancer and that breastfeeding in particular may mitigate the increased risk of ER-PR- cancers seen from multiparity.

Impact of body mass index on prognostically relevant breast cancer tumor characteristics

BACKGROUND

This study analyzes the association of body mass index (BMI) and prognostically relevant breast cancer (BC) characteristics in a country that has been rather spared of the global obesity epidemic.

PATIENTS AND METHODS

Based on 20-year data (1999-2009, n = 1,414) of the prospective relational BC database of the University Hospital Basel, Switzerland, the associations between BMI, tumor size and stage, histological subtype, grading, hormonal receptor status, HER2 status and 'triple-negative' status were evaluated. Multivariate analysis considered BMI and patient's age.

RESULTS

The association between increasing BMI and the above-mentioned variables were as follows (results described in each case: Beta-coefficient or odds ratio, 95% confidence interval, p value): tumor size, (1) entire cohort: 0.03 (0.01-0.05), p < 0.001, (2) tumor found by self-palpation: 0.05 (0.03-0.07), p < 0.001, (3) tumor found by radiological examination: 0.03 (0-0.07), p = 0.044; advanced TNM stage: 1.16 (1.02-1.31), p = 0.022; histological subtype: 1.04 (0.89-1.22), p = 0.602; unfavorable grading: 1.11 (1.00-1.25), p = 0.057; positive estrogen receptor status: 0.95 (0.83-1.09), p = 0.459; positive HER2 status: 0.92 (0.74-1.15), p = 0.467; presence of a 'triple-negative' carcinoma: 1.19 (0.93-1.52), p = 0.165. Consideration of only postmenopausal BC patients (n = 1,063) did attenuate the results, but did not change the direction of the associations with BMI.

CONCLUSION

BMI was positively associated with TNM stage, grading and tumor size for tumors that were found by self-detection, as well as for those lesions detected by radiological breast examinations.

The management of menopausal symptoms in breast cancer survivors: case-based approach

INTRODUCTION

The intensified treatment of breast cancer improves survival but has a price in terms of side-effects. The main side-effects, such as vasomotor symptoms and impaired sexual functioning, are related to premature menopause due to chemotherapy and/or anti-hormonal therapy. Though for some women these symptoms are bearable, for others they have a large impact on their quality of life. The paper discusses the menopausal symptoms most frequently reported by breast cancer survivors and current treatment options.

METHODS

A literature review is presented of menopausal symptoms after breast cancer and management strategies, illustrated by two cases.

SUMMARY

Vasomotor symptoms can be relieved by lifestyle adaptation, acupuncture and non-hormonal agents such as venlafaxine, gabapentin or clonidine. Impaired sexual functioning can be treated by couple-based sexual counselling or psycho-educational therapy. Painful intercourse due to vaginal dryness can be alleviated by vaginal lubricants and moisturizers, but is most effectively treated by vaginal estriol. Local estriol seems safe if used for a short period (less than six weeks). Because of proven increased risk of recurrence with hormone replacement therapy (HRT), it should not be prescribed for breast cancer survivors, although exceptions could be made of selected cases of fully informed BRCA mutation carriers after ER-negative breast cancer and with severe menopausal symptoms due to prophylactic oophorectomy at a young age and (preferably) after mastectomy.

CONCLUSION

The management of vasomotor symptoms and impaired sexual functioning in breast cancer survivors should focus on lifestyle and, if necessary, non-hormonal pharmacological interventions.

Association of hormone-related characteristics and breast cancer risk by estrogen receptor/progesterone receptor status in the shanghai breast cancer study

Etiologic differences between subtypes of breast cancer defined by estrogen receptor (ER) and progesterone receptor (PR) status are not well understood. The authors evaluated associations of hormone-related factors with breast cancer subtypes in a population-based case-control study involving 1,409 ER-positive (ER+)/PR-positive (PR+) cases, 712 ER-negative (ER-)/PR-negative (PR-) cases, 301 ER+/PR- cases, 254 ER-/PR+ cases, and 3,474 controls aged 20-70 years in Shanghai, China (phase I, 1996-1998; phase II, 2002-2005). Polytomous logistic regression and Wald tests for heterogeneity across subtypes were conducted. Breast cancer risks associated with age at menarche, age at menopause, breastfeeding, age at first livebirth, waist-to-hip ratio, and oral contraceptive use did not differ by hormone receptor status. Among postmenopausal women, higher parity (≥2 children vs. 1) was associated with reduced risk (odds ratio (OR) = 0.69, 95% confidence interval (CI): 0.52, 0.91) and higher body mass index (BMI; weight (kg)/height (m)(2)) with increased risk (highest quartile: OR = 2.40, 95% CI: 1.65, 3.47) of the ER+/PR+ subtype but was unrelated to the ER-/PR- subtype (for parity, P(heterogeneity) = 0.02; for BMI, P(heterogeneity) < 0.01). Hormone replacement therapy (OR = 2.25, 95% CI: 1.40, 3.62) and alcohol consumption (OR = 1.59, 95% CI: 1.01, 2.51) appeared to be preferentially associated with the ER+/PR- subtype. These findings indicate that BMI, parity, hormone replacement therapy, and alcohol consumption may play different roles in subtypes of breast cancer. More research is needed to better understand the etiology of 2 relatively rare subtypes, ER+/PR- tumors and ER-/PR+ tumors.

Population attributable risk of invasive postmenopausal breast cancer and breast cancer subtypes for modifiable and non-modifiable risk factors

BACKGROUND

The population-level impact of modifiable postmenopausal breast cancer risk factors is incompletely understood, especially regarding potential heterogeneity by estrogen receptor (ER) and progesterone receptor (PR) status.

METHODS

Using data on 3074 cases and 6386 controls from a population-based case-control study of postmenopausal breast cancer conducted in Germany between 2002 and 2005, we calculated multivariable-adjusted odds ratios and population attributable risks (PARs) for modifiable and non-modifiable risk factors. We examined overall postmenopausal invasive breast cancer as well as tumor ER/PR subtypes. A bootstrap method provided estimates of 95% confidence intervals (95%CIs).

RESULTS

The summary PARs (95%CIs) for non-modifiable risk factors (age at menarche, age at menopause, parity, benign breast disease, and family history of breast cancer) were 37.2% (27.1-47.2%) regarding overall invasive tumors, 36.5% (23.3-47.6%) regarding ER+/PR+ tumors, 47.9% (26.4-64.4%) regarding ER+/PR- tumors, and 31.1% (4.0-51.9%) regarding ER-/PR- tumors. Of the modifiable risk factors (hormone therapy (HT) use, physical inactivity, BMI, alcohol consumption), HT use and physical inactivity had the highest impact with PARs of 19.4% (15.9-23.2%) and 12.8% (5.5-20.8%), respectively, regarding overall invasive tumors. For ER+/PR+ tumors, the corresponding PARs were 25.3% (20.9-29.7%) and 16.6% (7.0-26.0%). The summary PARs (95%CIs) for HT use and physical inactivity together were 29.8% (21.8-36.9%) and 37.9% (30.6-46.2%) regarding overall invasive and ER+/PR+ tumors, respectively.

CONCLUSIONS

The population-level impact of modifiable risk factors appears to be comparable to that of non-modifiable risk factors. Alterations in HT use and physical inactivity could potentially reduce postmenopausal invasive breast cancer incidence in Germany by nearly 30%, with the largest potential for reduction among ER+/PR+ tumors, the most frequently diagnosed subtype.

Age-related variation in the relationship between menopausal hormone therapy and the risk of dying from breast cancer

Multiple past studies have reported a reduced risk of breast cancer-related mortality (BCM) in relation to pre-diagnostic use of hormone therapy (HT); however, the extent to which this reduction is due to heightened screening or tumor biology is unknown. Using a population-based cohort of 1,911 post-menopausal women diagnosed with invasive breast cancer at ages 45-79 from 1993 to 1999, we investigated the extent to which the reduced risk in BCM observed in relation to HT might be explained by screening patterns or tumor features. Estrogen-progestin therapy (EPT) use was associated with a decreased risk of BCM (after adjustment for age, study, mammography, stage, and treatment), but only among older women (ever use: ≥ 65 years: HR = 0.45 [95% CI 0.26-0.80]; <65 years: HR = 1.03 [95% CI 0.60-1.79]). Estrogen-alone therapy (ET) use was not associated with risk of BCM (ever use: ≥ 65 years: HR = 0.76 [95% CI 0.51-1.12]; <65 years: HR = 1.20 [95% CI 0.71-2.02]). HT users had a much greater frequency of mammography (P value <0.001). EPT use was associated with tumor characteristics related to improved prognosis in older women after adjustment for screening, including an inverse association with poorly differentiated tumors (OR = 0.57 [95% CI 0.38-0.85]) and an association with lobular tumors (OR = 1.68 [95% CI 1.07-2.65]). Beyond the influence of EPT use on screening uptake, these data indicate that the improved survival associated with pre-diagnostic EPT use may be due in part to the development of more favorable tumor characteristics.

Risk factors for ductal, lobular, and mixed ductal-lobular breast cancer in a screening population

BACKGROUND

Biological distinctions between histologic subtypes of breast cancer suggest etiologic differences, although few studies have been powered to examine such differences. We compared associations between several factors and risk of ductal, lobular, and mixed ductal-lobular breast cancers.

METHODS

We used risk factor data from the Breast Cancer Surveillance Consortium for 3,331,744 mammograms on 1,211,238 women, including 19,119 women diagnosed with invasive breast cancer following mammography (n = 14,818 ductal, 1,602 lobular, and 1,601 mixed ductal-lobular). Histologic subtype-specific risk factor associations were evaluated using Cox regression.

RESULTS

Significant positive associations with family history and breast density were similar across subtypes. Hormone therapy use was associated with increased risk of all subtypes, but was most strongly associated with lobular cancer [hazard ratio (HR) = 1.46; 95% confidence interval (CI), 1.25-1.70]. Relative to nulliparous women, parous women had lower risk of ductal and mixed but not lobular cancers (HR = 0.80; 95% CI, 0.76-0.84; HR = 0.79; 95% CI, 0.68-0.93; HR = 0.96; 95% CI, 0.81-1.15, respectively). Late age at first birth was associated with increased risk of all subtypes.

CONCLUSIONS

Similarities in risk factor associations with ductal, lobular, and mixed breast cancer subtypes were more pronounced than differences. Distinctions between subtype-specific associations were limited to analyses of hormone therapy use and reproductive history.

IMPACT

The results of this study indicate that the strongest risk factors for breast cancer overall (that is, family history and breast density) are not histologic subtype specific. Additional studies are needed to better characterize subtype-specific associations with genetic, hormonal, and nonhormonal factors.

Hormone replacement therapy (HRT), breast cancer and tumor pathology

Within an average observation period of 5-6 years, several clinical trials reported an increased risk of breast cancer due to hormone replacement therapy (HRT). However, it remains disputable, whether the increased rate of breast cancers detected within the given time frame is indeed due to newly induced tumors and thus constitutes HRT-initiated primary breast cancers. Onco-pathologically speaking it appears more likely that HRT stimulates the growth of already existing small tumor nests which - due to their small size - would otherwise go undiagnosed. The major arguments are: In summary, HRT is hence more likely to be a tumor promoter than a de novo-inducer of breast cancers.