Little is known about the etiologic profile of triple-negative breast cancer (negative for estrogen receptor/progesterone receptor/human epidermal growth factor), a breast cancer subtype associated ...with high mortality and inadequate therapeutic options. We undertook this study to assess the risk for triple-negative breast cancer among women 45 years of age and younger in relation to demographic/lifestyle factors, reproductive history, and oral contraceptive use. Study participants were ascertained in two previous population-based, case-control studies. Eligible cases included all primary invasive breast cancers among women ages 20 to 45 years in the Seattle-Puget Sound area, diagnosed between January 1983 and December 1992, for whom complete data was obtained for estrogen receptor, progesterone receptor, and human epidermal growth factor status (n = 897; including n = 187 triple-negative breast cancer cases). Controls were age matched and ascertained via random digit dialing. Oral contraceptive use > or =1 year was associated with a 2.5-fold increased risk for triple-negative breast cancer (95% confidence interval, 1.4-4.3) and no significantly increased risk for non-triple-negative breast cancer (P(heterogeneity) = 0.008). Furthermore, the risk among oral contraceptive users conferred by longer oral contraceptive duration and by more recent use was significantly greater for triple-negative breast cancer than non-triple-negative breast cancer (P(heterogeneity) = 0.02 and 0.01, respectively). Among women < or =40 years, the relative risk for triple-negative breast cancer associated with oral contraceptive use > or =1 year was 4.2 (95% confidence interval, 1.9-9.3), whereas there was no significantly increased risk with oral contraceptive use for non-triple-negative breast cancer among women < or =40 years, nor for triple-negative breast cancer or non-triple-negative breast cancer among women 41 to 45 years of age. In conclusion, significant heterogeneity exists for the association of oral contraceptive use and breast cancer risk between triple-negative breast cancer and non-triple-negative breast cancer among young women, lending support to a distinct etiology.
Research has suggested that use of combined estrogen and progestin hormone replacement therapy (CHRT) increases breast cancer risk and that CHRT use is more strongly associated with the risk of ...invasive lobular breast carcinoma than that of invasive ductal carcinoma. Lobular carcinoma is less common than ductal carcinoma but can be more difficult to diagnose because of its subtle elusive infiltrative pattern.
To evaluate trends in invasive lobular and ductal carcinoma incidence rates from 1987 through 1999, during which time use of CHRT increased in the United States.
Descriptive epidemiologic study.
Nine cancer registries that participate in the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute and that cover Atlanta, Ga; Detroit, Mich; San Francisco-Oakland, Calif; Seattle, Wash; and Connecticut, Hawaii, Iowa, New Mexico, and Utah.
Women 30 years of age and older residing in the areas covered by the 9 SEER registries.
Proportional changes in incidence rates of invasive lobular and ductal carcinoma among women with no prior history of breast cancer.
A total of 190 458 women were included in this analysis who were identified through the registries as having invasive breast cancer; 7682 of the 198 140 potentially eligible women (ie, those identified as not having in situ breast cancer) were excluded from this analysis because stage of cancer was unknown. Invasive breast cancer incidence rates adjusted for age and for SEER historic stage increased 1.04-fold (95% confidence interval CI, 1.004-1.07) from 1987-1999 (206.7/100 000 to 214.1/100 000, age-adjusted). However, incidence rates of tumors classified as lobular increased 1.52-fold (95% CI, 1.42-1.63), and those classified as mixed ductal-lobular increased 1.96-fold (95% CI, 1.80-2.14); rates of these types combined increased 1.65-fold (95% CI, 1.55-1.78) (19.8/100 000 to 33.4/100 000, age-adjusted). In contrast, ductal carcinoma rates remained largely constant (153.8/100 000 to 155.3/100 000, age-adjusted; proportional change, 1.03 95% CI, 0.99-1.06). The proportion of breast cancers with a lobular component increased from 9.5% in 1987 to 15.6% in 1999.
Ductal carcinoma incidence rates remained essentially constant from 1987-1999 while lobular carcinoma rates increased steadily. This increase presents a clinical challenge given that lobular carcinoma is more difficult to detect than ductal carcinoma by both physical examination and mammography.
Breast cancer incidence rates rose throughout the 1980s and 1990s in the United States but have recently declined through 2004. Studies reporting this decline primarily attribute it to the sharp ...decline in menopausal hormone use following publication of the Women's Health Initiative trial results. However, they have not stratified rates by either histologic type or race/ethnicity, which could further inform contributors to these trends. Using data from 13 cancer registries that participate in the Surveillance, Epidemiology, and End Results program, we evaluated annual percent changes (APC) in breast cancer incidence rates from 1995 to 2004 by histologic type and race/ethnicity for intervals identified using joinpoint regression. Invasive ductal carcinoma and invasive lobular carcinoma incidence rates fell steadily from 1998 to 2004 APC, -3.07% (95% confidence interval, -4.10 to -2.02) and APC, -3.18% (95% confidence interval, -5.18 to -1.03), respectively. Declines in rates of breast cancer overall and invasive ductal carcinoma were primarily limited to women > or = 50 years of age and to non-Hispanic whites and Asian/Pacific Islanders, and declines in rates of invasive lobular carcinoma were primarily limited to non-Hispanic whites. The majority of these declines began around 1998 and all began before 2002 when the Women's Health Initiative trial results were published; thus, the abrupt decline in hormone therapy use starting in 2002 is unlikely to be primarily responsible for the recent decline in breast cancer rates. The declines observed thus far are likely attributable to saturation of screening, although further declines related to the widespread cessation of hormone use may follow.
An outcome of considerable concern among breast cancer survivors is the development of second primary breast cancer. However, evidence regarding how potentially modifiable lifestyle factors modulate ...second breast cancer risk is limited. We evaluated the relationships between obesity, alcohol consumption, and smoking on risk of second primary invasive contralateral breast cancer among breast cancer survivors.
Utilizing a population-based nested case-control study design, we enrolled 365 patients diagnosed with an estrogen receptor-positive (ER+) first primary invasive breast cancer and a second primary contralateral invasive breast cancer, and 726 matched controls diagnosed with only an ER+ first primary invasive breast cancer. Obesity, alcohol use, and smoking data were ascertained from medical record reviews and participant interviews. Using conditional logistic regression we evaluated associations between these three exposures and second primary contralateral breast cancer risk.
Obesity, consumption of >or= 7 alcoholic beverages per week, and current smoking were all positively related to risk of contralateral breast cancer (odds ratio OR, 1.4; 95% CI, 1.0 to 2.1; OR, 1.9; 95% CI, 1.1 to 3.2; and OR, 2.2; 95% CI, 1.2 to 4.0, respectively). Compared with women who consumed fewer than seven alcoholic beverages per week and were never or former smokers, women who consumed >or= 7 drinks per week and were current smokers had a 7.2-fold (95% CI, 1.9 to 26.5) elevated risk of contralateral breast cancer.
Our population-based study adds to the limited available literature and suggests that obesity, smoking, and alcohol consumption influence contralateral breast cancer risk, affording breast cancer survivors three means of potentially reducing this risk.
Antihypertensive agents are the most commonly prescribed class of medications in the United States. Evidence regarding the relationship between different types of antihypertensives and breast cancer ...risk is sparse and inconsistent, and prior studies have lacked the capacity to assess impacts of long-term use.
To evaluate associations between use of various classes of antihypertensive medications and risks of invasive ductal and invasive lobular breast cancers among postmenopausal women.
Population-based case-control study in the 3-county Seattle-Puget Sound metropolitan area. Participants were women aged 55 to 74 years, 880 of them with invasive ductal breast cancer, 1027 with invasive lobular breast cancer, and 856 with no cancer serving as controls.
Recency and duration of use of antihypertensive medications.
Risks of invasive ductal and invasive lobular breast cancers.
Current use of calcium-channel blockers for 10 or more years was associated with higher risks of ductal breast cancer (odds ratio OR, 2.4; 95% CI, 1.2-4.9) (P= .04 for trend) and lobular breast cancer (OR, 2.6; 95% CI, 1.3-5.3) (P= .01 for trend). This relationship did not vary appreciably by type of calcium-channel blocker used (short-acting vs long-acting, dihydropyridines vs non-dihydropyridines). In contrast, use of diuretics, β-blockers, and angiotensin II antagonists were not associated with risk.
While some studies have suggested a positive association between calcium-channel blocker use and breast cancer risk, this is the first study to observe that long-term current use of calcium-channel blockers in particular are associated with breast cancer risk. Additional research is needed to confirm this finding and to evaluate potential underlying biological mechanisms.
Between 1987 and 1998, breast cancer incidence rates rose 0.5%/yr in the United States. A question of potential etiologic and clinical importance is whether the hormone receptor status of breast ...tumors is also changing over time. This is because hormone receptor status may reflect different etiologic pathways and is useful in predicting response to adjuvant therapy and prognosis.
Age-adjusted, age-specific breast cancer incidence rates by estrogen receptor (ER) and progesterone receptor (PR) status from 1992 to 1998 were obtained and compared from 11 population-based cancer registries in the United States that participate in the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program.
From 1992 to 1998, the overall proportion of breast cancers that were ER-positive and PR-positive increased from 75.4% to 77.5% (P =.0002) and from 65.0% to 67.7% (P <.0001), respectively, continuing trends observed before 1992. These increases were limited to women 40 to 69 years of age. The proportions of ER-positive/PR-positive tumors increased from 56.7% to 62.3% (P =.0010) among 40- to 49-year-olds, from 58.0% to 63.2% (P =.0002) among 50- to 59-year-olds, and from 63.2% to 67.9% (P =.0020) among 60- to 69-year-olds.
From 1992 to 1998, the proportion of tumors that are hormone receptor-positive rose as the proportion of hormone receptor-negative tumors declined. Because the incidence rates of hormone receptor-negative tumors remained fairly constant over these years, the overall rise in breast cancer incidence rates in the United States seems to be primarily a result of the increase in the incidence of hormone receptor-positive tumors. Hormonal factors may account for this trend.
Incidence rates of ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS) have increased rapidly over the past several decades largely due to the increased use of mammography. However, ...recent data from 1987 to 1999 indicate that invasive ductal carcinoma incidence rates have remained essentially constant, whereas rates of invasive lobular carcinoma have increased 65%, with greater increases observed among postmenopausal women. Data on recent trends in DCIS and LCIS incidence rates, particularly age-specific trends, are lacking. We evaluated trends in the incidence rates of DCIS overall, noncomedo DCIS, comedo DCIS, and LCIS using data from nine Surveillance, Epidemiology, and End Results cancer registries. DCIS incidence rates increased 7.2-fold 95% confidence interval (95% CI), 6.8-7.7 from 1980 to 2001, 1.8-fold (95% CI, 1.7-1.9) over the past 10 years (1992-2001), and 1.1-fold (95% CI, 1.0-1.2) over the past 5 years (1997-2001). The magnitudes of these increases were highest among women ages > or = 50 years. Furthermore, over the past 10- and 5-year periods, rates of noncomedo DCIS have generally increased across all age groups, whereas rates of comedo DCIS held constant or decreased. LCIS incidence rates increased 2.6-fold (95% CI, 2.3-2.9) from 1980 to 2001, 1.3-fold (95% CI, 1.2-1.5) over the past 10 years, and 1.1-fold (95% CI, 1.0-1.3) over the past 5 years. Similar to invasive lobular carcinoma, but unlike invasive ductal carcinoma, incidence rates of both DCIS and LCIS continue to increase in the United States primarily among older women. These trends present important public health and clinical challenges.
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