Second primary cancer risks according to race and ethnicity among U.S. breast cancer survivors

Breast cancer survivors have an increased risk of developing second primary cancers, yet risks by race and ethnicity have not been comprehensively described. We evaluated second primary cancer risks among 717,335 women diagnosed with first primary breast cancer (aged 20-84 years and survived ≥1-year) in the SEER registries using standardized incidence ratios (SIRs; observed/expected). SIRs were estimated by race and ethnicity compared with the racial- and ethnic-matched general population, and further stratified by clinical characteristics of the index breast cancer. Poisson regression was used to test for heterogeneity by race and ethnicity. SIRs for second primary cancer differed by race and ethnicity with the highest risks observed among non-Hispanic/Latina Asian American, Native Hawaiian, or other Pacific Islander (AANHPI), non-Hispanic/Latina Black (Black), and Hispanic/Latina (Latina) survivors and attenuated risk among non-Hispanic/Latina White (White) survivors (SIRAANHPI = 1.49, 95% CI = 1.44-1.54; SIRBlack = 1.41, 95% CI = 1.37-1.45; SIRLatina = 1.45, 95% CI = 1.41-1.49; SIRWhite = 1.09, 95% CI = 1.08-1.10; p-heterogeneity<.001). SIRs were particularly elevated among AANHPI, Black, and Latina survivors diagnosed with an index breast cancer before age 50 (SIRs range = 1.88-2.19) or with estrogen receptor-negative tumors (SIRs range = 1.60-1.94). Heterogeneity by race and ethnicity was observed for 16/27 site-specific second cancers (all p-heterogeneity's < .05) with markedly elevated risks among AANHPI, Black, and Latina survivors for acute myeloid and acute non-lymphocytic leukemia (SIRs range = 2.68-3.15) and cancers of the contralateral breast (SIRs range = 2.60-3.01) and salivary gland (SIRs range = 2.03-3.96). We observed striking racial and ethnic differences in second cancer risk among breast cancer survivors. Additional research is needed to inform targeted approaches for early detection strategies and treatment to reduce these racial and ethnic disparities.

Risk of second primary cancer among women in the Kaiser Permanente Breast Cancer Survivors Cohort

BACKGROUND

Breast cancer survivors are living longer due to early detection and advances in treatment and are at increased risk for second primary cancers. Comprehensive evaluation of second cancer risk among patients treated in recent decades is lacking.

METHODS

We identified 16,004 females diagnosed with a first primary stage I-III breast cancer between 1990 and 2016 (followed through 2017) and survived ≥ 1 year at Kaiser Permanente (KP) Colorado, Northwest, and Washington. Second cancer was defined as an invasive primary cancer diagnosed ≥ 12 months after the first primary breast cancer. Second cancer risk was evaluated for all cancers (excluding ipsilateral breast cancer) using standardized incidence ratios (SIRs), and a competing risk approach for cumulative incidence and hazard ratios (HRs) adjusted for KP center, treatment, age, and year of first cancer diagnosis.

RESULTS

Over a median follow-up of 6.2 years, 1,562 women developed second cancer. Breast cancer survivors had a 70% higher risk of any cancer (95%CI = 1.62-1.79) and 45% higher risk of non-breast cancer (95%CI = 1.37-1.54) compared with the general population. SIRs were highest for malignancies of the peritoneum (SIR = 3.44, 95%CI = 1.65-6.33), soft tissue (SIR = 3.32, 95%CI = 2.51-4.30), contralateral breast (SIR = 3.10, 95%CI = 2.82-3.40), and acute myeloid leukemia (SIR = 2.11, 95%CI = 1.18-3.48)/myelodysplastic syndrome (SIR = 3.25, 95%CI = 1.89-5.20). Women also had elevated risks for oral, colon, pancreas, lung, and uterine corpus cancer, melanoma, and non-Hodgkin lymphoma (SIR range = 1.31-1.97). Radiotherapy was associated with increased risk for all second cancers (HR = 1.13, 95%CI = 1.01-1.25) and soft tissue sarcoma (HR = 2.36, 95%CI = 1.17-4.78), chemotherapy with decreased risk for all second cancers (HR = 0.87, 95%CI = 0.78-0.98) and increased myelodysplastic syndrome risk (HR = 3.01, 95%CI = 1.01-8.94), and endocrine therapy with lower contralateral breast cancer risk (HR = 0.48, 95%CI = 0.38-0.60). Approximately 1 in 9 women who survived ≥ 1 year developed second cancer, 1 in 13 developed second non-breast cancer, and 1 in 30 developed contralateral breast cancer by 10 years. Trends in cumulative incidence declined for contralateral breast cancer but not for second non-breast cancers.

CONCLUSIONS

Elevated risks of second cancer among breast cancer survivors treated in recent decades suggests that heightened surveillance is warranted and continued efforts to reduce second cancers are needed.

Racial and ethnic disparities in treatment-related heart disease mortality among U.S. breast cancer survivors

BACKGROUND

Racial/ethnic disparities in heart disease mortality by initial treatment type among breast cancer survivors have not been well described.

METHODS

We included 739,557 women diagnosed with first primary invasive breast cancer between 2000-2017 (aged 18-84 years, received surgery, survived ≥one year, followed through 2018) in the SEER-18 database. Standardized mortality ratios (SMRs; observed/expected) were calculated by race/ethnicity (Non-Hispanic/Latina Asian American, Native Hawaiians, and other Pacific Islanders [AANHP]); Non-Hispanic/Latina Black [Black]; Hispanic/Latina [Latina]; and Non-Hispanic/Latina White [White]) and initial treatment (surgery only; chemotherapy+surgery; chemotherapy, radiotherapy, +surgery; and radiotherapy+surgery) compared to the racial/ethnic-matched general population, and by clinical characteristics. Cumulative heart disease mortality was estimated accounting for competing risks.

RESULTS

SMRs were elevated for Black and Latina women treated with surgery only and chemotherapy+surgery (range = 1.15-1.21) and AANHPI women treated with chemotherapy, radiotherapy, +surgery (1.29; 95%CI = 1.11,1.48), whereas SMRs were <1 for White women (range = 0.70-0.96). SMRs were especially high for women with advanced (regional/distant) stage among Black women for all treatment (range = 1.15-2.89) and for AANHPI and Latina women treated with chemotherapy+surgery (range = 1.28-3.61). Non-white women diagnosed at age < 60 had higher SMRs, as did Black and AANHPI women diagnosed with estrogen receptor positive breast cancers. Black women had the highest ten-year cumulative risk of heart disease mortality: age < 60 (Black : 1.78%; 95%CI = 1.63%,1.94%) compared to White, AANHPI, and Latina women (<1%), and age ≥ 60 (Black : 7.92%; 95%CI = 7.53%,8.33%) compared to White, AANHPI, and Latina women (range = 3.90%-6.48%).

CONCLUSIONS

Our findings illuminated striking racial/ethnic disparities in heart disease mortality among Black, AANHPI, and Latina breast cancer survivors, especially after initial chemotherapy receipt.

County-level geographic disparities in cardiovascular disease mortality among US breast cancer survivors, 2000-2018

BACKGROUND

Disparities in cardiovascular disease mortality among breast cancer survivors are documented, but geographic factors by county-level socioeconomic status (SES) and rurality are not well described.

METHODS

We analyzed 724 518 women diagnosed with localized or regional stage breast cancer between 2000 and 2017 within Surveillance, Epidemiology, and End Results Program-18 with follow-up until 2018. We calculated relative risks (RRs) of cardiovascular disease mortality using Poisson regression, accounting for age- and race-specific rates in the general population, according to county-level quintiles of SES (measured by Yost index), median income, and rurality at breast cancer diagnosis. We also calculated 10-year cumulative mortality risk of cardiovascular disease accounting for competing risks.

RESULTS

Cardiovascular disease mortality was 41% higher among breast cancer survivors living in the lowest SES (RR = 1.41, 95% confidence interval [CI] = 1.36 to 1.46, Ptrend < .001) and poorest (RR = 1.41, 95% CI = 1.36 to 1.47, Ptrend < .001) counties compared with the highest SES and wealthiest counties, and 24% higher for most rural relative to most urban counties (RR = 1.24, 95% CI = 1.17 to 1.30, Ptrend < .001). Disparities for the lowest SES relative to highest SES counties were greatest among younger women aged 18-49 years (RR = 2.32, 95% CI = 1.90 to 2.83) and aged 50-59 years (RR = 2.01, 95% CI = 1.77 to 2.28) and within the first 5 years of breast cancer diagnosis (RR = 1.53, 95% CI = 1.44 to 1.64). In absolute terms, however, disparities were widest for women aged 60+ years, with approximately 2% higher 10-year cumulative cardiovascular disease mortality risk in the poorest compared with wealthiest counties.

CONCLUSIONS

Geographic factors at breast cancer diagnosis were associated with increased cardiovascular disease mortality risk. Studies with individual- and county-level information are needed to inform public health interventions and reduce disparities among breast cancer survivors.

Treatment-related thoracic soft tissue sarcomas in US breast cancer survivors: a retrospective cohort study

BACKGROUND

Soft tissue sarcoma is a rare but serious side-effect of radiotherapy to treat breast cancer, and rates are increasing in the USA. We evaluated potential co-factors in two complimentary cohorts of US breast cancer survivors.

METHODS

In this retrospective cohort study, we sourced data from the Kaiser Permanente (KP) cohort and the Surveillance, Epidemiology, and End Results (SEER) 13 registries cohort, both in the USA. The KP cohort included 15 940 women diagnosed with breast cancer from Jan 1, 1990, to Dec 31, 2016, in KP Colorado, KP Northwest (which serves Oregon and Southwest Washington state), or KP Washington, with detailed treatment data and comorbidities (including hypertension and diabetes at or before breast cancer diagnosis) from electronic medical records. The SEER cohort included 457 300 women diagnosed with breast cancer from Jan 1, 1992, to Dec 31, 2016, within the 13 SEER registries across the USA, with initial treatment data (yes vs no or unknown). Eligibility criteria in both cohorts were female breast cancer survivors (stage I-III) aged 20-84 years at diagnosis who had breast cancer surgery, and had survived at least 1 year after breast cancer diagnosis. The outcome of interest was any second thoracic soft tissue sarcoma (angiosarcomas and other subtypes) that developed at least 1 year after breast cancer diagnosis. Risk factors for thoracic soft tissue sarcoma were assessed using multivariable Poisson regression models.

FINDINGS

In the KP cohort, median follow-up was 9·3 years (IQR 5·7-13·9) and 19 (0·1%) of 15 940 eligible, evaluable women developed a thoracic soft tissue sarcoma (11 angiosarcomas, eight other subtypes). Most (94·7%; 18 of 19) thoracic soft tissue sarcomas occurred in women treated with radiotherapy; thus, radiotherapy was associated with a significantly increased risk of developing a thoracic soft tissue sarcoma (relative risk [RR] 8·1 [95% CI 1·1-60·4]; p=0·0052), but there was no association with prescribed dose, fractionation, or boost. The RR of angiosarcoma after anthracyclines was 3·6 (95% CI 1·0-13·3; p=0·058). Alkylating agents were associated with an increased risk of developing other sarcomas (RR 7·7 [95% CI 1·2-150·8]; p=0·026). History of hypertension (RR 4·8 [95% CI 1·3-17·6]; p=0·017) and diabetes (5·3 [1·4-20·8]; p=0·036) were each associated with around a five-times increased risk of angiosarcoma. In the SEER cohort, 430 (0·1%) of 457 300 patients had subsequent thoracic soft tissue sarcomas (268 angiosarcomas and 162 other subtypes) after a median follow-up of 8·3 years (IQR 4·3-13·9). Most (77·9%; 335 of 430) cases occurred after radiotherapy; thus, radiotherapy was associated with a significantly increased risk of developing a thoracic soft tissue sarcoma (RR 3·0 [95% CI 2·4-3·8]; p<0·0001) and, for angiosarcomas, the RR for breast-conserving surgery plus radiotherapy versus mastectomy plus radiotherapy was 1·9 (1·1-3·3; p=0·012). By 10 years after radiotherapy, the cumulative incidence of thoracic soft tissue sarcoma was 0·21% (95% CI 0·12-0·34) in the KP cohort and 0·15% (95% CI 0·13-0·17) in SEER.

INTERPRETATION

Radiotherapy was the strongest risk factor for thoracic soft tissue sarcoma in both cohorts. This finding, along with the novel findings for diabetes and hypertension as potential risk factors for angiosarcomas, warrant further investigation as potential targets for prevention strategies and increased surveillance.

FUNDING

US National Cancer Institute and National Institutes of Health.

Trends in heart disease mortality among breast cancer survivors in the US, 1975-2017

Purpose

Heart disease is a significant concern among breast cancer survivors, in part due to cardiotoxic treatments including chemotherapy and radiotherapy. Long-term trends in heart disease mortality have not been well characterized. We examined heart disease mortality trends among US breast cancer survivors by treatment type.

Methods

We included first primary invasive breast cancer survivors diagnosed between 1975 and 2016 (aged 18–84; survived 12 + months; received initial chemotherapy, radiotherapy, or surgery) in the SEER-9 Database. Standardized mortality ratios (SMRs) and 10-year cumulative heart disease mortality estimates accounting for competing events were calculated by calendar year of diagnosis and initial treatment regimen. P_trends were assessed using Poisson regression. All statistical tests were 2-sided.

Results

Of 516,916 breast cancer survivors, 40,812 died of heart disease through 2017. Heart disease SMRs declined overall from 1975–1979 to 2010–2016 (SMR 1.01 [95%CI: 0.98, 1.03] to 0.74 [0.69, 0.79], p_trend < 0.001). This decline was also observed for survivors treated with radiotherapy alone and chemotherapy plus radiotherapy. A sharper decline in heart disease SMRs was observed from 1975 to 1989 for left-sided radiotherapy, compared to right-sided. In contrast, there was a non-significant increasing trend in SMRs for chemotherapy alone, and significant by regional stage (p_trend = 0.036). Largest declines in 10-year cumulative mortality were observed from 1975–1984 to 2005–2016 among surgery only: 7.02% (95%CI: 6.80%, 7.23%) to 4.68% (95%CI: 4.39%, 4.99%) and radiotherapy alone: 6.35% (95%CI: 5.95%, 6.77%) to 2.94% (95%CI: 2.73%, 3.16%).

Conclusions

We observed declining heart disease mortality trends by most treatment types yet increasing for regional stage patients treated with chemotherapy alone, highlighting a need for additional studies with detailed treatment data and cardiovascular management throughout cancer survivorship.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10549-022-06515-5.

Assessment of surveillance versus etiologic factors in the reciprocal association between papillary thyroid cancer and breast cancer

BACKGROUND

Mutually increased risks for thyroid and breast cancer have been reported, but the contribution of etiologic factors versus increased medical surveillance to these associations is unknown.

METHODS

Leveraging large-scale US population-based cancer registry data, we used standardized incidence ratios (SIRs) to investigate the reciprocal risks of thyroid and breast cancers among adult females diagnosed with a first primary invasive, non-metastatic breast cancer (N = 652,627) or papillary thyroid cancer (PTC) (N = 92,318) during 2000-2017 who survived ≥1-year.

RESULTS

PTC risk was increased 1.3-fold [N = 1434; SIR = 1.32; 95 % confidence interval (CI) = 1.25-1.39] after breast cancer compared to the general population. PTC risk declined significantly with time since breast cancer (Poisson regression = P_trend <0.001) and was evident only for tumors ≤2 cm in size. The SIRs for PTC were higher after hormone-receptor (HR)+ (versus HR-) and stage II or III (versus stage 0-I) breast tumors. Breast cancer risk was increased 1.2-fold (N = 2038; SIR = 1.21; CI = 1.16-1.26) after PTC and was constant over time since PTC but was only increased for stage 0-II and HR + breast cancers.

CONCLUSION

Although some of the patterns by latency, stage and size are consistent with heightened surveillance contributing to the breast-thyroid association, we cannot exclude a role of shared etiology or treatment effects.

All-Cause and Cardiovascular Disease Mortality Among Breast Cancer Survivors in CLUE II, a Long-Standing Community-Based Cohort

BACKGROUND

There is growing evidence that breast cancer survivors have higher cardiovascular disease (CVD) mortality relative to the general population. Information on temporal patterns for all-cause and CVD mortality among breast cancer survivors relative to cancer-free women is limited.

METHODS

All-cause and CVD-related mortality were compared in 628 women with breast cancer and 3140 age-matched cancer-free women within CLUE II, a prospective cohort. We calculated adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) using Cox proportional hazards regression for all-cause mortality, and Fine and Gray models for CVD-related mortality to account for competing risks.

RESULTS

Over 25 years of follow-up, 916 deaths occurred (249 CVD related). Breast cancer survivors had an overall higher risk of dying compared with cancer-free women (HR = 1.79, 95% CI = 1.53 to 2.09) irrespective of time since diagnosis, tumor stage, estrogen receptor status, and older age at diagnosis (≥70 years). Risk of death was greatest among older survivors at more than 15 years after diagnosis (HR = 2.69, 95% CI = 1.59 to 4.55). CVD (69.1% ischemic heart disease) was the leading cause of death among cancer-free women and the second among survivors. Survivors had an increase in CVD-related deaths compared with cancer-free women beginning at 8 years after diagnosis (HR = 1.65, 95% CI = 1.00 to 2.73), with the highest risk among older survivors (HR = 2.24, 95% CI = 1.29 to 3.88) and after estrogen receptor-positive disease (HR = 1.85, 95% CI = 1.06 to 3.20).

CONCLUSIONS

Breast cancer survivors continue to have an elevated mortality compared with the general population for many years after diagnosis. Preventing cardiac deaths, particularly among older breast cancer patients, could lead to reductions in mortality.

Risk factors for contralateral breast cancer in postmenopausal breast cancer survivors in the NIH-AARP Diet and Health Study

PURPOSE

The role of established breast cancer risk factors and clinical characteristics of the first breast cancer in the development of contralateral breast cancer (CBC) among postmenopausal women is unclear.

METHODS

We identified 10,934 postmenopausal women diagnosed with a first primary breast cancer between 1995 and 2011 in the NIH-AARP Diet and Health Study. CBC was defined as a second primary breast cancer diagnosed in the contralateral breast ≥ 3 months after the first breast cancer. Exposures included pre-diagnosis risk factors (lifestyle, reproductive, family history) and clinical characteristics of the first breast cancer. We used multivariable Cox proportional hazards regression to estimate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over a median follow-up of 6.8 years, 436 women developed CBC. We observed an increasing trend in CBC risk by age (p-trend = 0.002) and decreasing trend by year of diagnosis (p-trend = 0.001) of the first breast cancer. Additional risk factor associations were most pronounced for endocrine therapy (HR 0.68, 95% CI 0.53-0.87) and family history of breast cancer (HR 1.38, 95% CI 1.06-1.80, restricted to invasive first breast cancer). No associations were found for lifestyle (body mass index, physical activity, smoking, alcohol) or reproductive factors (age at menarche, parity, age at first birth, age at menopause).

CONCLUSIONS

This study suggests that clinical characteristics of the first breast cancer and family history of breast cancer, but not pre-diagnosis lifestyle and reproductive factors, are strongly associated with CBC risk among postmenopausal women. Future studies are needed to understand how these factors contribute to CBC etiology and to identify further opportunities for prevention.

Risk of contralateral breast cancer according to first breast cancer characteristics among women in the USA, 1992-2016

Background

Estimates of contralateral breast cancer (CBC) risk in the modern treatment era by year of diagnosis and characteristics of the first breast cancer are needed to assess the impact of recent advances in breast cancer treatment and inform clinical decision making.

Methods

We examined CBC risk among 419,818 women (age 30–84 years) who were diagnosed with a first unilateral invasive breast cancer and survived ≥ 1 year in the US Surveillance, Epidemiology, and End Results program cancer registries from 1992 to 2015 (follow-up through 2016). CBC was defined as a second invasive breast cancer in the contralateral breast ≥ 12 months after the first breast cancer. We estimated standardized incidence ratios (SIRs) of CBC by year of diagnosis, age at diagnosis, and tumor characteristics for the first breast cancer. Cumulative incidence of CBC was calculated for women diagnosed with a first breast cancer in the recent treatment era (2004–2015, follow-up through 2016).

Results

Over a median follow-up of 8 years (range 1–25 years), 12,986 breast cancer patients developed CBC. Overall, breast cancer patients had approximately twice the risk of developing cancer in the contralateral breast when compared to that expected in the general population (SIR = 2.21, 95% CI = 2.17–2.25). SIRs for CBC declined by year of first diagnosis, irrespective of age at diagnosis and estrogen receptor (ER) status (p-trends < 0.001), but the strongest decline was after an ER-positive tumor. The 5-year cumulative incidence of CBC ranged from 1.01% (95% CI = 0.90–1.14%) in younger women (age < 50 years) with a first ER-positive tumor to 1.89% (95% CI = 1.61–2.21%) in younger women with a first ER-negative tumor.

Conclusion

Declines in CBC risk are consistent with continued advances in breast cancer treatment. The updated estimates of cumulative incidence inform breast cancer patients and clinicians on the risk of CBC and may help guide treatment decisions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13058-021-01400-3.

Abstract 5805: Treatment-associated endocrine symptoms and change in ultrasound tomography measures of breast density after tamoxifen therapy

Background: Tamoxifen therapy has been shown to have greater therapeutic benefit among women whose breast density declines subsequent to treatment than among women whose density does not decline. Although limited data suggests that endocrine symptoms after tamoxifen initiation may be associated with improved breast cancer outcomes, it is unknown whether these symptoms are associated with reductions in breast density. We therefore evaluated endocrine symptoms and change in breast density in a 12-month longitudinal study of women undergoing tamoxifen therapy for clinical indications.

Methods: Cohort members (N=74) were aged 30-74 years in the Ultrasound Study of Tamoxifen at Karmanos Cancer Institute and Henry Ford Health Systems (Detroit, MI). Endocrine symptoms and breast density were both assessed prior to tamoxifen initiation (T0) and at 1-3 months (T1), 4-6 months (T2), and approximately 12 months (T3) post-tamoxifen initiation. Treatment-associated endocrine symptoms included treatment-emergent or increasing vasomotor and/or joint symptoms. Endocrine symptom severity was also assessed with a Likert scale for symptom frequency and categorized as no symptoms (score=0), low/moderate symptoms (score=1-5), and high symptoms (score=6+). Sound speed (m/s), a surrogate of volumetric breast density, was measured with whole breast ultrasound tomography. Change in breast density was calculated as density at T1-T3 minus density at T0. We used multivariable linear regression to estimate mean change in density by endocrine symptoms adjusting for age, race, menopausal status, body mass index, and baseline sound speed. Generalized estimating equations were used to account for within-subject correlations over time.

Results: Women with treatment-associated endocrine symptoms had an overall greater mean reduction in breast density compared with women without symptoms (mean change [95% CI]: -1.97 m/s [-3.80, -0.13]; -0.27 m/s [- 3.50, 2.95], respectively; p=0.22). Longitudinal trends in breast density significantly differed for women with versus without treatment-associated endocrine symptoms (p-interaction=0.02). Significant declines in breast density over time were observed among women with treatment-associated endocrine symptoms (p-trend=0.005), but not among women without symptoms (p-trend=0.16). Similar trends in breast density decline were observed among women with higher symptom severity (p-trends for no symptoms=0.53; low/moderate symptoms=0.04; high symptoms=0.008).

Conclusions: These findings suggest that treatment-associated endocrine symptoms may be associated with a significant decline in breast density after tamoxifen initiation. Further studies are needed to assess whether these observations can predict clinical outcome, and if confirmed, both treatment-associated endocrine symptoms and observed reductions in breast density may be useful for patients and providers to improve adherence.

Citation Format: Cody Ramin, Ruth Pfeiffer, Shaoqi Fan, Maeve Mullooly, Roni T. Falk, Mark A. Sak, Michael S. Simon, David H. Gorski, Haythem Ali, Peter Littrup, Nebojsa Duric, Mark E. Sherman, Gretchen L. Gierach. Treatment-associated endocrine symptoms and change in ultrasound tomography measures of breast density after tamoxifen therapy [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5805.

Contralateral breast cancer risk according to first breast cancer characteristics among United States women from 1992 to 2015

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Background: After recent advances in breast cancer treatment and increasing uptake of contralateral prophylactic mastectomies, estimates of contralateral breast cancer (CBC) risk by year of diagnosis and other patient characteristics are needed to help inform decision making. Methods: We estimated CBC risk in 399,032 1-year survivors of a first primary breast cancer (stage I-III) in the US Surveillance, Epidemiology, and End Results Database (1992-2015). CBC was defined as an invasive second breast cancer diagnosed in the opposite breast 12+ months after the first breast cancer diagnosis. We estimated standardized incidence ratios (SIRs) and 5-year cumulative incidence of CBC by calendar period, age, breast cancer subtype, and receipt of hormonal therapy for the initial breast cancer. SIRs were calculated as the observed number of CBCs among survivors compared to the expected number of first breast cancers in the general population. Cumulative incidence was estimated in women without contralateral prophylactic mastectomies and accounted for competing risks. Results: Among 399,032 breast cancer survivors, 11,365 cases of CBC were diagnosed through 2015. Risk of CBC was elevated over the entire study period (SIR = 2.23, 95% CI = 2.19-2.27). SIRs for CBC declined over calendar period and this decreasing trend was observed irrespective of age, estrogen receptor (ER) status, and hormonal therapy. Survivors had an overall 5-year cumulative incidence of CBC of 1.49% (95% CI = 1.44%-1.54%), which decreased over time to 1.31% (95% CI = 1.23%-1.41%) in 2008-2014. For recent diagnoses, the 5-year cumulative incidence of CBC was higher after ER-negative (1.80%, 95% CI = 1.55%-2.07%) and triple negative tumors (1.98%, 95% CI = 1.52%-2.55%), and lowest for women who received hormonal therapy (1.01%, 95% CI = 0.90%-1.13%). Conclusions: Although CBC risk is declining in the US from 1992-2015, survivors have approximately twice the risk of an incident breast cancer (in the contralateral breast) compared to the general population. The 5-year cumulative risk of CBC is highest after ER-negative/triple negative tumors highlighting the need for medical surveillance and targeted interventions among these patients.

The estrogen receptor-alpha S118P variant does not affect breast cancer incidence or response to endocrine therapies

PURPOSE

Estrogen receptor-alpha (ER) is a therapeutic target of ER-positive (ER+) breast cancers. Although ER signaling is complex, many mediators of this pathway have been identified. Specifically, phosphorylation of ER at serine 118 affects responses to estrogen and therapeutic ligands and has been correlated with clinical outcomes in ER+ breast cancer patients. We hypothesized that a newly described germline variant (S118P) at this residue would drive cellular changes consistent with breast cancer development and/or hormone resistance.

METHODS

Isogenic human breast epithelial cell line models harboring ER S118P were developed via genome editing and characterized to determine the functional effects of this variant. We also examined the frequency of ER S118P in a case-control study (N = 536) of women with and without breast cancer with a familial risk.

RESULTS

In heterozygous knock-in models, the S118P variant demonstrated no significant change in proliferation, migration, MAP Kinase pathway signaling, or response to the endocrine therapies tamoxifen and fulvestrant. Further, there was no difference in the prevalence of S118P between women with and without cancer relative to population registry databases.

CONCLUSIONS

This study suggests that the ER S118P variant does not affect risk for breast cancer or hormone therapy resistance. Germline screening and modification of treatments for patients harboring this variant are likely not warranted.

Evaluation of osteopenia and osteoporosis in younger breast cancer survivors compared with cancer-free women: a prospective cohort study

BACKGROUND

Osteoporosis, an indicator of significant bone loss, has been consistently reported among older breast cancer survivors. Data are limited on the incidence of osteopenia, an earlier indicator of bone loss, and osteoporosis in younger breast cancer survivors compared with cancer-free women.

METHODS

We prospectively examined bone loss in 211 breast cancer survivors (mean age at breast cancer diagnosis = 47 years) compared with 567 cancer-free women in the same cohort with familial risk for breast cancer. Multivariable-adjusted Cox proportional hazards models were used to estimate HRs and 95% CIs of osteopenia and/or osteoporosis incidence based on physician diagnosis.

RESULTS

During a mean follow-up of 5.8 years, 66% of breast cancer survivors and 53% of cancer-free women reported having a bone density examination, and 112 incident cases of osteopenia and/or osteoporosis were identified. Breast cancer survivors had a 68% higher risk of osteopenia and osteoporosis compared to cancer-free women (HR = 1.68, 95% CI = 1.12-2.50). The association was stronger among recent survivors after only 2 years of follow-up (HR = 2.74, 95% CI = 1.37-5.47). A higher risk of osteopenia and osteoporosis was also observed among survivors aged ≤ 50 years, estrogen receptor-positive tumors, and those treated with aromatase inhibitors alone or chemotherapy plus any hormone therapy relative to cancer-free women.

CONCLUSIONS

Younger breast cancer survivors are at higher risk for osteopenia and osteoporosis compared to cancer-free women. Studies are needed to determine effective approaches to minimize bone loss in this population.

Night shift work at specific age ranges and chronic disease risk factors

OBJECTIVES

We examined the association of night shift work history and age when night shift work was performed with cancer and cardiovascular disease risk factors among 54 724 women in the Nurses' Health Study (NHS) II.

METHODS

We calculated age-adjusted and socioeconomic status-adjusted means and percentages for cancer and cardiovascular risk factors in 2009 across categories of night shift work history. We used multivariable-adjusted logistic regression to estimate odds ratios (ORs) and 95% CIs for key risk factors among 54 724 participants (72% ever shift workers). We further examined these associations by age (20-25, 26-35, 36-45 and 46+ years) at which shift work was performed.

RESULTS

Ever night shift workers had increased odds of obesity (body mass index ≥30 kg/m(2); OR=1.37, 95% CI 1.31 to 1.43); higher caffeine intake (≥131 mg/day; OR=1.16, 95% CI 1.12 to 1.22) and total calorie intake (≥1715 kcal/day; OR=1.09, 95% CI 1.04 to 1.13); current smoking (OR=1.30, 95% CI 1.19 to 1.42); and shorter sleep durations (≤7 h of sleep/day; OR=1.19, 95% CI 1.15 to 1.24) compared to never night shift workers. These estimates varied depending on age at which night work was performed, with a suggestion that night shift work before age 25 was associated with fewer risk factors compared to night shift work at older ages.

CONCLUSIONS

Our results indicate that night shift work may contribute to an adverse chronic disease risk profile, and that risk factors may vary depending on the age at which night shift work was performed.

Chronotype and breast cancer risk in a cohort of US nurses

The aim of this study was to examine the relation between chronotype and breast cancer risk. We analyzed the association between chronotype (definite morning type, probable morning type, probable evening type, definite evening type, or neither morning nor evening type) and breast cancer risk among 72 517 women in the Nurses' Health Study II (NHS II). Chronotype was self-reported in 2009, and 1834 breast cancer cases were confirmed among participants between 1989 and 2007; a 2-yr lag period was imposed to account for possible circadian disruptions related to breast cancer diagnosis. Age- and multivariable-adjusted logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). Participants who self-reported as neither morning nor evening type had a 27% increased risk of breast cancer (multivariable-adjusted OR = 1.27, 95% CI = 1.04-1.56), compared with definite morning types. None of the other chronotypes were significantly associated with breast cancer risk (multivariable-adjusted OR = 0.99, 95% CI = 0.87-1.12 for probable morning versus definite morning types; OR = 0.96, 95% CI = 0.84-1.09 for probable evening versus definite morning types; and OR = 1.15, 95% CI = 0.98-1.34 for definite evening versus definite morning types). Overall, chronotype was not associated with breast cancer risk in our study. A modestly increased risk among neither morning nor evening types may indicate circadian disruption as a potentially underlying mechanism; however, more studies are needed to confirm our results.

Distribution of asbestos bodies in the human lung as determined by bronchoalveolar lavage

Asbestos-related lung diseases tend to have distinct local distributions, for example, asbestosis first appears and tends to be more severe in the peripheral parts of the lower lung zones. The risk for asbestosis is related to the total asbestos burden of the lung. This suggests that the lower lobes in asbestos-exposed individuals may contain more asbestos than the other lobes. To test whether such topographic differences exist, we compared the number of retrieved asbestos bodies (AB) per ml BAL fluid in three groups of occupationally asbestos-exposed subjects who underwent BAL at different sampling sites. In Group 1 (n = 24) we performed BAL at three sites, namely in a segment of the right upper, right middle, and right lower lobe, to evaluate differences in asbestos body burden from lung apex to basis. There was a distinct increase in BAL asbestos body concentrations from the upper (21.2 +/- 9.1 AB/ml BAL fluid) to the middle (30.4 +/- 12.8 AB/ml BAL fluid) and to the lower lobe (56.0 +/- 20.2 AB/ml BAL fluid), all differences being significant (p < 0.01). In Group 2 (n = 40), we found good interlobar correlations for asbestos body counts between the right middle lobe (21.0 +/- 5.8 AB/ml BAL fluid) and the lingula (22.4 +/- 5.9 AB/ml BAL fluid) (r = 0.941, p < 0.001) and, in Group 3 (n = 15), between the ventral basal segment of the right (41.2 +/- 13.6 AB/ml BAL fluid) and left lung (39.0 +/- 13.6 AB/ml BAL fluid) (r = 0.966, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)