Obesity-associated changes in molecular biology of primary breast cancer

Obesity is associated with an increased risk of developing breast cancer (BC) and worse prognosis in BC patients, yet its impact on BC biology remains understudied in humans. This study investigates how the biology of untreated primary BC differs according to patients' body mass index (BMI) using data from >2,000 patients. We identify several genomic alterations that are differentially prevalent in overweight or obese patients compared to lean patients. We report evidence supporting an ageing accelerating effect of obesity at the genetic level. We show that BMI-associated differences in bulk transcriptomic profile are subtle, while single cell profiling allows detection of more pronounced changes in different cell compartments. These analyses further reveal an elevated and unresolved inflammation of the BC tumor microenvironment associated with obesity, with distinct characteristics contingent on the estrogen receptor status. Collectively, our analyses imply that obesity is associated with an inflammaging-like phenotype. We conclude that patient adiposity may play a significant role in the heterogeneity of BC and should be considered for BC treatment tailoring.

Clinical and Molecular Characteristics of ER-Positive Ultralow Risk Breast Cancer Tumors Identified by the 70-Gene Signature

The metastatic potential of estrogen receptor (ER)-positive breast cancers is heterogenous and distant recurrences occur months to decades after primary diagnosis. We have previously shown that patients with tumors classified as ultralow risk by the 70-gene signature have a minimal long-term risk of fatal breast cancer. Here, we evaluate the previously unexplored underlying clinical and molecular characteristics of ultralow risk tumors in 538 ER-positive patients from the Stockholm tamoxifen randomized trial (STO-3). Out of the 98 ultralow risk tumors, 89% were luminal A molecular subtype, whereas 26% of luminal A tumors were of ultralow risk. Compared with other ER-positive tumors, ultralow risk tumors were significantly (Fisher's test, P<0.05) more likely to be of smaller tumor size, lower grade, progesterone receptor (PR)-positive, human epidermal growth factor 2 (HER2)-negative and have low Ki-67 levels (proliferation-marker). Moreover, ultralow risk tumors showed significantly lower expression scores of multi-gene modules associated with the AKT/mTOR-pathway, proliferation (AURKA), HER2/ERBB2-signaling, IGF1-pathway, PTEN-loss, and immune response (IMMUNE1 and IMMUNE2), and higher expression scores of the PIK3CA-mutation-associated module. Furthermore, 706 genes were significantly (FDR<0.001) differentially expressed in ultralow risk tumors, including lower expression of genes involved in immune response, PI3K/Akt/mTOR-pathway, histones, cell cycle, DNA repair, apoptosis, and higher expression of genes coding for epithelial-to-mesenchymal transition, and homeobox proteins, among others. In conclusion, ultralow risk tumors, associated with minimal long-term risk of fatal disease, differ from other ER-positive tumors, including luminal A molecular subtype tumors. Identification of these characteristics is important to improve our prediction of non-fatal versus fatal breast cancer. This article is protected by copyright. All rights reserved.

Abstract PD10-07: Chemokine12 (CK12) tertiary lymphoid gene expression signature as a predictor of response in 3 immunotherapy arms of the neoadjuvant ISPY 2 TRIAL - pembrolizumab with and without SD101, and durvalumab combined with olaparib - and in 9 other arms of the trial including platinum-based and dual-anti-HER2 therapies

Background: The CK12 expression signature consists of genes CCL2, CCL3, CCL4, CCL5, CCL8, CCL18, CCL19, CCL21, CXCL9, CXCL10, CXCL11, CXCL13 and was previously shown to associate with the presence of T and B cell rich tertiary lymphoid structures in melanoma and other cancers, and with better patient survival independent of tumor staging and treatment. I-SPY 2 is a biomarker-rich, phase II neoadjuvant platform trial for high risk early stage breast cancer. Here we leverage the I-SPY 2 biomarker program to test the hypothesis that this signature associates with sensitivity to neoadjuvant immunotherapies and potentially other classes cancer therapeutics in breast cancer. Methods: Data from 1130 patients across 12 arms of I-SPY2 (control (ctr): 210; veliparib/carboplatin (VC): 71; neratinib (N): 114; MK2206: 93; ganitumab: 106; ganetespib: 93; AMG386: 134; TDM1/pertuzumab(P): 52; H/P: 44; pembrolizumab (pembro): 69; durvalumab/olaparib (durva/olap): 71; pembro/SD101: 72) were available for analysis. Pre-treatment FF (n=987) or FFPE (n=143) biopsies were assayed using Agilent gene expression arrays. Signature scores were calculated as the average expression level across the 12 genes, after z-score normalization. We used logistic modeling to assess association with pCR in each arm in a model adjusting for HR and HER2 (likelihood ratio test, p&lt;0.05). This analysis was also performed within HR/HER2 receptor subsets, numbers permitting. We also assessed differences in levels across HR/HER2 subsets using ANOVA and Tukey post-hoc testing. Our statistics are descriptive rather than inferential and do not adjust for multiplicities of other biomarkers outside this study. Results: CK12 levels associate with HR/HER2 status (ANOVA p=1.07E-14), with higher levels in TN and HR-HER2+ subsets and lower levels in HR+ groups. Overall, patients with higher levels of CK12 were significantly more likely to achieve pCR in all 3 IO arms: pembro (OR=3.4/1SD), pembro/SD101 (OR=4/1SD), and durva/olaparib (OR=2.5/1SD) (LR p&lt;0.05), in a model adjusting for HR status. The CK12 performed favorably in predicting response to pembro/SD101 compared to several other genomic signatures measuring intratumoral immune response. Higher CK12 also associates with response to the ANG1/2 inhibitor AMG386, an agent known to have immune modulatory activity. Higher CK12 was moderately associated with pCR in the control (OR=2.0/1SD), neratinib (OR=1.7/1SD), veliparib/carboplatin (OR=2.0/1SD), ganitumab (OR= 1.7/1SD) and TDM1/P arms (OR=2.1/1SD). Within the HR+HER2- subset, CK12 associated with pCR in all three IO arms, and in the control, AMG386, ganitumab, and ganetespib arms. Within the smaller TN subset, it associated with response in pembro and pembro/SD101 arms but not in durva/olaparib, and in the neratinib and AMG386 arms. Chemokine12 mostly did not associate with pCR in HER2+ subsets, except for HR+HER2+ patients treated with neratinib, and HR-HER2+ patients in the original control arm (trastuzumab). Conclusion: The CK12 signature is highly predictive of complete pathologic response to immuno-oncology agents and other therapeutics supporting the role of the crosstalk within the tumor immune microenvironment in predicting response across subtypes. This gene expression signature can be readily obtained from microarrays and warrants further investigation in future arms of ISPY2 as a predictive biomarker.

Citation Format: Hatem Soliman, Denise Wolf, Jo Chien, Christina Yau, Michael Campbell, Mark Magbanua, Ruixiao Lu, Nicholas O'Grady, Lamorna Brown-Swigart, Gillian Hirst, Beverly Parker, Laura Sit, Smita Asare, Doug Yee, Angie DeMichele, Rita Nanda, Lajos Pusztai, Don Berry, Laura Esserman, Laura Van't Veer. Chemokine12 (CK12) tertiary lymphoid gene expression signature as a predictor of response in 3 immunotherapy arms of the neoadjuvant ISPY 2 TRIAL - pembrolizumab with and without SD101, and durvalumab combined with olaparib - and in 9 other arms of the trial including platinum-based and dual-anti-HER2 therapies [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD10-07.

Abstract PS9-05: Concordance between patient-reported and physician-documented comorbidities among stage 4 breast cancer patients

Background

Comorbidities in metastatic breast cancer patients (pts) impact treatment decisions, eligibility for clinical trials, and influence prognosis and quality of life (QoL). The aim of this study was to evaluate the concordance between pt-reported and physician-documented (PD) comorbidities in an electronic medical record to (1) reliably document pts’ health histories to establish eligibility for clinical trials and novel therapeutics, and, (2) identify comorbidities that may be more comprehensively reported by pts rather than physicians.

Patients and Methods

All new pts at UCSF’s Breast Care Center (BCC) are administered an electronic intake survey that includes an assessment of pt-reported health history, comorbidities and symptoms. Between November 2016 and March 2020, 305 pts self-reported metastatic breast cancer (described as “breast cancer spread to sites other than breast or axillary lymph nodes”), and 222 consented to use of their clinical data for research. Chart-reviews were conducted for PD comorbidities at their initial BCC clinic visit. Pt and physician concordance was summarized for 54 comorbidities. Cohen’s kappa (κ) was used to quantify level of agreement. Concordance was classified using Landis and Koch thresholds with agreement as poor or slight (κ &lt;0.20), fair (κ ≥0.20 to &lt;0.40), moderate (κ ≥0.40 to &lt;0.60), substantial (κ ≥0.60 to &lt;0.80), or almost perfect (κ ≥0.80).

Results

Of the 222 pts, 37 pts (17%) incorrectly reported having metastatic breast cancer, 4 (2%) had duplicate surveys, 7 (3%) cancelled appointment and 5 (2%) had metastatic cancer from another primary. Thus, 168 pts with confirmed metastatic disease were included in the analysis (median age, 56 years; age range, 29-86 years; median time from diagnosis of metastatic breast cancer, 0.46 years). Highest PD comorbidities were obesity, hypertension (HTN) and thyroid disease, while highest reported comorbidities by pts were HTN, depression and arthritis. 23 of 54 comorbidities had a moderate to high level of agreement between physician and pt reports (κ≥0.40). As shown in Table 1, agreement was high for diabetes (type 1 or 2), HTN and thyroid disease, moderate for asthma/bronchitis and depression, and low for obesity, anxiety, stomach ulcers/gastroesophageal reflux disease (GERD) and arthritis.

Conclusion

In this review of data collected as part of routine care at an academic medical center, rates of comorbidities were relatively low, and there is substantial variance in the concordance of comorbidity reporting between pt and physicians. Pt-reported comorbidity data may help physicians more comprehensively document conditions such as depression, anxiety, arthritis and stomach ulcers/GERD, which in some cases may be subjective in nature but may significantly impact a pt’s quality of life and performance status. However, pts may underreport conditions such as obesity and heart disease, and inaccurately report other conditions such as non-insulin dependent diabetes. Recognition of depression, anxiety and GERD as comorbidities is important since some medications for these conditions may be contraindicated in some clinical trials.

Understanding this concordance data may inform how we collect pt reported data to optimize understanding of a pt’s global health condition.

Table 1: Concordance between physician-documented and patient-reported comorbiditiesComorbidityPhysician ReportedPatient ReportedConcordanceκDiabetes6%5%98%0.83Hypertension24%20%93%0.79Thyroid Disease20%18%92%0.74Insulin dependent Diabetes1%1%99%0.66Depression11%20%87%0.51Asthma/bronchitis12%15%89%0.51Stomach ulcers/ GERD11%18%84%0.36Obesity34%15%75%0.36Heart disease/heart valve disease7%4%93%0.32Anxiety10%18%83%0.30Non-insulin dependent diabetes3%1%97%0.27Arthritis9%20%78%0.14

Citation Format: Saumya Umashankar, Michelle E. Melisko, Madeline Matthys, Laura Van't Veer, Amrita Basu. Concordance between patient-reported and physician-documented comorbidities among stage 4 breast cancer patients [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS9-05.

Abstract OT-22-01: Opportunities and lessons learned in using electronic health record patient portal (MyChart) for recruitment to the population-based WISDOM study

Background: WISDOM is a preference-tolerant, pragmatic study comparing annual mammogram screening to personalized, risk-based breast screening in healthy women with a target accrual of 100,000. This sizable recruitment goal requires creative and broad-based strategies that are not typical for traditional clinical research. One of the recruitment methods is use of an electronic health record patient portal (Epic’s MyChart) to invite patients to participate in research. We tested various MyChart implementation strategies across WISDOM recruitment sites and report response rates, barriers and lessons learned. The study is registered on ClinicalTrials.gov, NCT02620852. Methods: Women aged 40-74 years with no history of breast cancer, DCIS, or double mastectomy can join the WISDOM Study online at wisdomstudy.org. Participants either elect to be randomized or self-select one of the study arms, the control (annual mammogram screening) arm or the treatment (personalized, risk-based breast screening) arm. All study steps can be completed electronically, with no requirement to travel to a study site. University of California, Los Angeles (UCLA) was the first WISDOM site to gain approval to use MyChart as a recruitment tool as part of the Clinical Translational Science Institute pilot in Spring 2018. The pilot was designed to demonstrate feasibility, patient response, and recruitment metrics. Following UCLA’s pilot, additional WISDOM sites received approval to use MyChart; however, implementation differed across sites based on local medical center leadership decisions. MyChart Implementation: As of July 2020, use of MyChart is ongoing at five of WISDOM’s six initial recruitment sites (UCLA, Sanford Health, UCSF, UCSD, UCI). Three sites (UCLA, Stanford, and UCSF) implemented MyChart broadly, and two sites (UCI and UCSD) are phasing in MyChart recruitment. UCLA and Sanford Health implemented MyChart recruitment through a centralized approach targeting all eligible patients and sending a MyChart invitation with a link to the study’s enrollment website. UCSF was approved to send WISDOM information on the MyChart portal, but the patients must opt in to learn more by outreach from a research coordinator. UCSD and UCI approaches are more limited requiring departmental or primary care provider approval for communications to be sent to patients. Results: MyChart enabled direct communication to a large number of potential study participants at UCLA and Sanford Health (UCLA 107,829, Sanford Health 86,684) during a 12-month period. The experiences of both sites were similar in that 50% of individuals read the MyChart message, 2.5-5% registered for additional information, and 1.5-2.5% consented to participate. UCSF’s implementation approach was similar with 8005 individuals invited, 6.6% indicating interest to participate, and 2.4% consenting. Although the number of consented participants represented a small portion of the total women consented to join the study to date, the recruitment rates from using MyChart were 2.5-10X higher compared to sites that did not use it or were in pilot phase. Participating sites saw 30%-50% increased recruitment rates during periods when MyChart messages were in use. Implementations at the departmental (UCSD) and primary care provider level (UCI) demonstrated similar trends (3.8% and 3% consented respectively), albeit with smaller samples. Conclusions: Use of electronic health record patient portal (MyChart) recruitment for the WISDOM Study increased enrollment rate by site and is a cost-effective approach to recruiting for large scale trials with broad eligibility criteria like the WISDOM Study.

Citation Format: Antonio Petruse, Alyssa Rocha, Liliana Johansen, Neil Wenger, Mandy Che, Steele Fors, Hannah L Park, Janet Wernisch, Irene Acerbi, Allison S Fiscalini, Jasmin Hassam, Andrea LaCroix, Barbara Parker, Lisa Madlensky, Laura Van't Veer, Celia Kaplan, Hoda Anton-Culver, Andrea Kaster, Skye Stewart, Samrrah Rouf, Alexander Borowsky, Ian Hurley, Robert Hiatt, Vivian Lee, Diane Heditsian, Susie Brain, Olufunmilayo Olopade, Deepa Sheth, Laura Esserman, Wisdom Study and Athena Breast Health Network Investigators and Advocate Partners, Arash Naeim. Opportunities and lessons learned in using electronic health record patient portal (MyChart) for recruitment to the population-based WISDOM study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr OT-22-01.

Abstract PD13-02: Site of recurrence after neoadjuvant therapy: A multi-center pooled analysis

Background: Achieving a pathologic complete response (pCR) has been shown on the patient level to predict excellent long-term event-free survival outcomes. Residual cancer burden (RCB) quantifies the extent of residual disease for patients who did not achieve pCR. We have previously observed in the I-SPY 2 TRIAL that while metastatic events outside the central nervous system (CNS) were dramatically reduced in the setting of pCR, the incidence of CNS metastasis remained similar across RCB classes, raising the possibility that these CNS events may be independent of response in the breast. In this study, we evaluate the type and sites of recurrences by RCB in a large pooled dataset, which allows for analysis within subtype, to validate these findings. Methods: 5161 patients pooled across 12 institutions/trials with available RCB and event-free survival (EFS) data were included in this analysis. EFS was calculated as the interval between treatment initiation, and locoregional recurrence, distant recurrence or death from any cause; patients without event are censored at time of last follow-up. The median follow-up is 4.6 years. We summarized the EFS event type, further sub-dividing the distant recurrence events (DR) by their site of relapse (CNS-only, CNS and other sites, Non-CNS). We used a competing risk (Fine-Gray) model to assess which of these site-specific relapses differ between RCB classes and estimated the cumulative incidence of CNS-only and non-CNS events at 5 years. Analyses were performed across the entire study population and within HR/HER2 defined subtypes. Results: Among the 5161 subjects, there were 1164 EFS events, including 92 (7.9%) local recurrences (without distant recurrence and/or death) and 1072 distant recurrence-free survival (DRFS) events. Among the DRFS events, 158 patients died without a distant recurrence. 914 experienced distant recurrences, including 90 (9.8%) with CNS-only, 145 (15.9%) with CNS and other sites, 664 (72.6%) with non-CNS distant recurrence; 15 (1.6%) patients had missing recurrence site information. Table 1 summarizes the cumulative incidence of CNS-only and non-CNS recurrence at 5 years and the proportion of CNS-only recurrences among DR events by RCB class overall and within each HR/HER2 subtypes. The incidence of CNS-only recurrences was low and similar across RCB classes. In contrast, the incidence of non-CNS recurrences increases with increasing RCB. As a result, CNS-only recurrences are proportionally higher within the RCB-0 and RCB-I than in the RCB-II and RCB-III groups, largely because of the low DR event rate and relative low frequency of non-CNS recurrence events within the RCB-0 and RCB-I classes. Overall, 27% of the recurrences in the setting of pCR (RCB-0) are due to CNS-only recurrences.Conclusions: Consistent with previous studies, our large pooled analysis confirmed that CNS-only recurrences are uncommon but appear similar across RCB groups, independent of response, suggesting that the CNS is a treatment sanctuary site. In contrast, non-CNS recurrence rates increase as RCB increases. These findings suggest that inclusion of CNS-only recurrences as an outcome event may impact the association between neoadjuvant therapy response and long-term outcomes in the context of current therapies. Novel therapies that cross the blood brain barrier will be needed to impact CNS recurrence rates.

Table 1: Cumulative Incidence of CNS Only and non-CNS Distant Recurrences at 5 years and proportion of CNS-only events among DR eventsRCB Class0IIIIIIpOverall (5161)N16766622017806Cum. Inc. CNS Only2%2%2%1%0.627Cum. Inc. Non-CNS3%6%16%27%&lt;0.001# CNS-Only / # DR events (%)26/96 (27%)14/74 (19%)39/443 (9%)11/301 (4%)HR-HER2- (1774)N770212590202Cum. Inc. CNS Only2%3%2%4%0.298Cum. Inc. Non-CNS4%11%19%42%&lt;0.001# CNS-Only / # DR events (%)13/50 (26%)6/32 (19%)13/148 (9%)8/111 (7%)HR-HER2+ (572)N3766710029Cum. Inc. CNS Only1%5%5%0%0.022Cum. Inc. Non-CNS2%5%18%38%&lt;0.001# CNS-Only / # DR events (%)4/17 (24%)3/10 (30%)6/31 (19%)0/13 (0%)HR+HER2+ (858)N31317229182Cum. Inc. CNS Only1%1%2%0%0.37Cum. Inc. Non-CNS2%3%15%26%&lt;0.001# CNS-Only / # DR events (%)3/10 (30%)2/16 (12%)7/68 (10%)0/29 (0%)HR+HER2- (1957)N2172111036493Cum. Inc. CNS Only3%2%1%0.2%0.087Cum. Inc. Non-CNS5%4%13%20%&lt;0.001# CNS-Only / # DR events (%)6/19 (32%)3/16 (19%)13/196 (7%)3/148 (2%)

Citation Format: Sonal Shad, Marieke van der Noordaa, Marie Osdoit, Diane de Croze, Anne-Sophie Hamy, Marick Lae, Fabien Reyal, Miguel Martin, María Del Monte-Millán, Sara López-Tarruella, I-SPY 2 TRIAL Consortium, Judy C Boughey, Matthew P Goetz, Tanya Hoskin, Rebekah Gould, Vicente Valero, Gabe Sonke, Tessa G Steenbruggen, Maartje van Seijen, Jelle Wesseling, John Bartlett, Stephen Edge, Mi-Ok Kim, Jean Abraham, Carlos Caldas, Helena Earl, Elena Provenzano, Stephen-John Sammut, David Cameron, Ashley Graham, Peter Hall, Lorna Mackintosh, Fan Fang, Andrew K Godwin, Kelsey Schwensen, Priyanka Sharma, Angela DeMichele, Janet Dunn, Louise Hiller, Larry Hayward, Jeremy Thomas, Kimberly Cole, Lajos Pusztai, Laura Van't Veer, Fraser Symmans, Laura Esserman, Christina Yau. Site of recurrence after neoadjuvant therapy: A multi-center pooled analysis [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PD13-02.

Integration of Health Questionnaire Systems to Facilitate Supportive Care Services for Patients at an Academic Breast Care Center

PURPOSE

This study evaluated the use of an electronic Health Questionnaire System (HQS) within the University of California San Francisco Breast Care Center as a screening and triage tool to proactively recognize patients' supportive care needs during new patient consultations and identify demographic characteristics associated with referrals to three supportive care services.

PATIENTS AND METHODS

A total of 428 patients with and without breast cancer between the ages of 18 and 84 years completed HQS intake forms before appointments at the University of California San Francisco Breast Care Center between November 2014 and May 2015 and agreed to participate in this study. Patient HQS responses triggered referrals to supportive care services, and a review of electronic health records was conducted to determine the outcomes of these referrals.

RESULTS

A total of 242 patients (56.5%) met criteria for at least one supportive care referral. Women with invasive breast cancer or ductal carcinoma in situ met criteria for supportive services more frequently than women without breast cancer diagnoses (76.9% v 23.8%; P < .001) and were most likely to receive referrals for genetic counseling (67.0%), psychological services (32.2%), and social services (12.1%). Multivariable logistic regression analysis showed that being married was associated with fewer referrals to social work (OR, 0.42; 95% CI, 0.21 to 0.81) and that those between 45 and 54 years of age were less likely to receive referrals to genetic counseling than those ≥ 55 years of age (OR, 0.41; 95% CI, 0.23 to 0.73). Among all referrals (n = 369), 26.8% resulted in completed appointments.

CONCLUSION

Using an automated intake form is an efficient way to identify and triage individuals in need of supportive care services and can provide insight into the populations with supportive care needs for targeted outreach.

Expanded Genomic Profiling of Circulating Tumor Cells in Metastatic Breast Cancer Patients to Assess Biomarker Status and Biology Over Time (CALGB 40502 and CALGB 40503, Alliance)

Purpose: We profiled circulating tumor cells (CTCs) to study the biology of blood-borne metastasis and to monitor biomarker status in metastatic breast cancer (MBC).Methods: CTCs were isolated from 105 patients with MBC using EPCAM-based immunomagnetic enrichment and fluorescence-activated cells sorting (IE/FACS), 28 of whom had serial CTC analysis (74 samples, 2-5 time points). CTCs were subjected to microfluidic-based multiplex QPCR array of 64 cancer-related genes (n = 151) and genome-wide copy-number analysis by array comparative genomic hybridization (aCGH; n = 49).Results: Combined transcriptional and genomic profiling showed that CTCs were 26% ESR1-ERBB2-, 48% ESR1+ERBB2-, and 27% ERBB2+ Serial testing showed that ERBB2 status was more stable over time compared with ESR1 and proliferation (MKI67) status. While cell-to-cell heterogeneity was observed at the single-cell level, with increasingly stable expression in larger pools, patient-specific CTC expression "fingerprints" were also observed. CTC copy-number profiles clustered into three groups based on the extent of genomic aberrations and the presence of large chromosomal imbalances. Comparative analysis showed discordance in ESR1/ER (27%) and ERBB2/HER2 (23%) status between CTCs and matched primary tumors. CTCs in 65% of the patients were considered to have low proliferation potential. Patients who harbored CTCs with high proliferation (MKI67) status had significantly reduced progression-free survival (P = 0.0011) and overall survival (P = 0.0095) compared with patients with low proliferative CTCs.Conclusions: We demonstrate an approach for complete isolation of EPCAM-positive CTCs and downstream comprehensive transcriptional/genomic characterization to examine the biology and assess breast cancer biomarkers in these cells over time. Clin Cancer Res; 24(6); 1486-99. ©2018 AACR.

Standard anthracycline-based vs. docetaxel-capecitabine in early breast cancer: Results from the chemotherapy randomization (R-C) of EORTC 10041/ BIG 3-04 MINDACT phase III trial

516

Background: The MINDACT trial demonstrated that 46% of breast cancer patients (pts) at high clinical (C) but low genomic (G) risk based on MammaPrint (70-gene signature), might safely forego adjuvant CT (Cardoso NEJM 2016). A second 1:1 randomization (R-C) was optional in all pts for whom CT was decided, between standard anthracycline-based regimens (AT) and experimental docetaxel 75 mg/m² IV + oral capecitabine 825 mg/m² bid x 14 days (DC), q3wks for 6 cycles after surgery. Methods: MINDACT included 6693 pts, of whom 2895 received CT. C-low/G-low pts were allocated to no CT, C-high/G-high to CT and those with discordant G/C results were randomized to use either G or C risk to decide use of CT. Primary endpoint for R-C was disease-free survival (DFS). Secondary endpoints included OS and safety. Statistical hypothesis: HR-0.76 in favour of DC. Results: A total of 1301 pts (45%), of whom 787 (61%) were C-high/G-high, 351 (27%) C-high/G-low, 137 (11%) C-low/G-high, and 26 (2%) C-low/G-low, were randomized to AT or DC. Main reason for not inclusion in R-C was CT given outside the trial. Compliance rates for R-C were 97% overall. At 5-years median follow-up, DFS was not significantly different between AT (649 pts) and DC (652 pts) [HR = 0.83 (0.60- 1.15, p = 0.263], and OS was similar in both arms (HR 0.91, 95% CI, 0.54- 1.53). For the relevant C-high/G-high group, DFS was also not different (5-years DFS 86.1 vs 88.1%; HR 0.83, 95% CI, 0.58-1.21). Of note, number of events is still small (AT: 30; DC: 27). Commonest adverse events in DC were grade 2 hand/foot syndrome (28.5% vs 3.3%), grade 2 diarrhea (13.7% vs 5.8%) and grade 1 peripheral neuropathy (27.1% vs 11.2%). Grade 2 anemia (14.2% vs 5.1%) and grade 4 neutropenia (24.6% vs 20.5%) were higher in AT. Cardiac events occurred in 9 pts overall, including 1 cardiac failure (AT), while 53 pts developed secondary cancers (AT: 32; DC: 21; leukemia: 2 in AT vs. 1 in DC). Four deaths occurred (AT:1 and DC:3) while on therapy. Conclusions: Docetaxel-capecitabine did not improve DFS or OS, compared with standard anthracycline-based CT, including for the C-high/G-high group. Safety profile of both regimens was as expected. Clinical trial information: NCT00433589.

Pembrolizumab plus standard neoadjuvant therapy for high-risk breast cancer (BC): Results from I-SPY 2

506

Background: Pembro is an anti-PD-1 antibody with single agent activity in HER2– metastatic BC. I-SPY 2 is a multicenter, phase 2 platform trial which evaluates novel neoadjuvant therapies; the primary endpoint is pathological complete response (pCR, ypT0/Tis ypN0). We report current efficacy results, with final results at ASCO. Methods: Patients (pts) with invasive BC ≥2.5 cm by exam or ≥2 cm by imaging are assigned weekly paclitaxel x 12 (control) +/- an experimental agent, followed by doxorubicin/cyclophosphamide x 4. Combinations of hormone-receptor (HR), HER2, & MammaPrint (MP) status define the 8 signatures studied. MP low HR+ BC is excluded. Adaptive randomization is based on each arm’s Bayesian probability of superiority over control. Graduation by signature is based on an arm’s Bayesian predictive probability of a successful 1:1 randomized phase 3 trial with a pCR endpoint. We provide raw & Bayesian estimated pCR rates adjusted for covariates, time effects over the course of the trial, & serial MRI modeling for pts not yet assessed for pCR surgically. Results: 69 pts were randomized to pembro (HER2- subsets only) from Dec 2015 until it graduated in Nov 2016. 46 pts have undergone surgery (table); the other 23 have on-therapy MRI assessments. In 29 HR–/HER2– (TNBC) pts, pembro increased raw & estimated pCR rates by >50% & 40%, respectively; in 40 HR+/HER– pts, it did so by 13% and 21%. 5 pts had immune-related grade 3 adverse events (AEs); 1 hypophysitis & 4 adrenal insufficiency. 4 pts presented after completion of AC (149-179 d after starting pembro); 1 presented prior to AC (37 d after starting pembro). 7 pts had grade 1-2 thyroid abnormalities. Conclusion: Pembro added to standard therapy improved pCR rates in all HER2- BCs that meet I-SPY 2 eligibility, especially in TNBC. Immune-mediated AEs were observed; pt follow up is ongoing. Clinical trial information: NCT01042379. [Table: see text]

High-throughput automated scoring of Ki67 in breast cancer tissue microarrays from the Breast Cancer Association Consortium

Automated methods are needed to facilitate high-throughput and reproducible scoring of Ki67 and other markers in breast cancer tissue microarrays (TMAs) in large-scale studies. To address this need, we developed an automated protocol for Ki67 scoring and evaluated its performance in studies from the Breast Cancer Association Consortium. We utilized 166 TMAs containing 16,953 tumour cores representing 9,059 breast cancer cases, from 13 studies, with information on other clinical and pathological characteristics. TMAs were stained for Ki67 using standard immunohistochemical procedures, and scanned and digitized using the Ariol system. An automated algorithm was developed for the scoring of Ki67, and scores were compared to computer assisted visual (CAV) scores in a subset of 15 TMAs in a training set. We also assessed the correlation between automated Ki67 scores and other clinical and pathological characteristics. Overall, we observed good discriminatory accuracy (AUC = 85%) and good agreement (kappa = 0.64) between the automated and CAV scoring methods in the training set. The performance of the automated method varied by TMA (kappa range= 0.37-0.87) and study (kappa range = 0.39-0.69). The automated method performed better in satisfactory cores (kappa = 0.68) than suboptimal (kappa = 0.51) cores (p-value for comparison = 0.005); and among cores with higher total nuclei counted by the machine (4,000-4,500 cells: kappa = 0.78) than those with lower counts (50-500 cells: kappa = 0.41; p-value = 0.010). Among the 9,059 cases in this study, the correlations between automated Ki67 and clinical and pathological characteristics were found to be in the expected directions. Our findings indicate that automated scoring of Ki67 can be an efficient method to obtain good quality data across large numbers of TMAs from multicentre studies. However, robust algorithm development and rigorous pre- and post-analytical quality control procedures are necessary in order to ensure satisfactory performance.

Patient utilization of supportive care services identified through the Athena Breast Health Questionnaire System

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Background: Psychological wellbeing and lifestyle changes are important factors in long-term health of cancer survivors. As part of the Athena Breast Health Network, the UCSF Breast Care Center (BCC) incorporated an electronic health questionnaire system (HQS) that collects patient-reported data on physical and psychological symptoms, medical conditions, family history, and lifestyle to identify patients’ supportive care needs. Methods: Through a semi-automated process, patients whose HQS responses meet pre-established thresholds are referred to Psycho-Oncology, social work, genetic counseling, and Onco-Fertility. Referrals generated within the HQS are signed and routed by clinicians at the time of a BCC visit. When patients decline appointments with these services, staff members document reasons within the electronic medical record (EMR). A retrospective chart review identified patients who did not receive supportive care services to which they were referred and a qualitative analysis was performed. Results: From 7/1/14-12/31/14, 525 patients completed an HQS and agreed to have their data used for research. The table summarizes referral information. 45 patients referred to Psycho-Oncology did not complete an appointment. Of these, ten did not respond to phone contact to schedule visits. 35 were reached, but declined an appointment. 25 (71.4%) were not ready to make an appointment; 5 (14.3%) cited distance as a primary barrier; 3 (8.6%) were satisfied with the psychological services they were receiving elsewhere; and 2 (5.7%) did not have insurance coverage. Reasons women disregarded referrals for genetic counseling and fertility are being evaluated. Conclusions: HQS can assist in identifying patient supportive care needs, but despite automation of referrals, many patients do not follow through to use supportive care and clinical resources. Timing and resource accessibility may be key. Through analysis of reasons for non-utilization, we hope to better tailor the delivery of supportive care services, when indicated, to better serve patient needs. [Table: see text]

The NIH BD2K center for big data in translational genomics

The world's genomics data will never be stored in a single repository - rather, it will be distributed among many sites in many countries. No one site will have enough data to explain genotype to phenotype relationships in rare diseases; therefore, sites must share data. To accomplish this, the genetics community must forge common standards and protocols to make sharing and computing data among many sites a seamless activity. Through the Global Alliance for Genomics and Health, we are pioneering the development of shared application programming interfaces (APIs) to connect the world's genome repositories. In parallel, we are developing an open source software stack (ADAM) that uses these APIs. This combination will create a cohesive genome informatics ecosystem. Using containers, we are facilitating the deployment of this software in a diverse array of environments. Through benchmarking efforts and big data driver projects, we are ensuring ADAM's performance and utility.

Xenografts faithfully recapitulate breast cancer-specific gene expression patterns of parent primary breast tumors

Though xenografts are used extensively for drug development in breast cancer, how well xenografts reflect the breadth of primary breast tumor subtypes has not been well characterized. Moreover, few studies have compared the gene expression of xenograft tumors to the primary tumors from which they were derived. Here we investigate whether the ability of human breast tumors (n = 20) to create xenografts in immune-deficient mice is associated with breast cancer immunohistochemical (IHC) and intrinsic subtype. We also characterize how precisely the gene expression of xenografts reprises that of parent breast tumors, using hierarchical clustering and other correlation-based techniques applied to Agilent 44K gene expression data from 16 samples including four matched primary tumor-xenograft pairs. Of the breast tumors studied, 25 % (5/20) generated xenografts. Receptor and intrinsic subtype were significant predictors of xenograft success, with all (4/4) triple-negative (TN) tumors and no (0/12) HR+Her2- tumors forming xenografts (P = 0.0005). Tumor cell expression of ALDH1, a stem cell marker, trended toward successful engraftment (P = 0.14), though CDK5/6, a basal marker, did not. Though hierarchical clustering across the 500 most variable genes segregated human breast tumors from xenograft tumors, when clustering was performed over the PAM50 gene set the primary tumor-xenograft pairs clustered together, with all IHC subtypes clustered in distinct groups. Greater similarity between primary tumor-xenograft pairs relative to random pairings was confirmed by calculation of the within-pair between-pair scatter ratio (WPBPSR) distribution (P = 0.0269), though there was a shift in the xenografts toward more aggressive features including higher proliferation scores relative to the primary. Triple-negative breast tumors demonstrate superior ability to create xenografts compared to HR+ tumors, which may reflect higher proliferation or relatively stroma-independent growth of this subtype. Xenograft tumors' gene expression faithfully resembles that of their parent tumors, yet also demonstrates a shift toward more aggressive molecular features.

International expert consensus on primary systemic therapy in the management of early breast cancer: highlights of the Fourth Symposium on Primary Systemic Therapy in the Management of Operable Breast Cancer, Cremona, Italy (2010)

A panel of international breast cancer experts formulated a declaration of consensus regarding many key issues in the use of primary systemic therapy (PST) either in clinical routine or research practice. The attainment of pathological complete response (pCR), defined as no residual invasive tumor in the surgical specimens both in breast and in axillary nodes, is one of the main goals of PST, and pCR can be used as the primary objective in prospective clinical trials. However, pCR is not a reliable endpoint with all treatment approaches, and alternatives such as Ki67 index of the residual invasive disease or after 2 weeks of PST are also potential endpoints. PST has several advantages: breast conservation and the unique opportunity to obtain information on the interaction between treatment and tumor biology. Changes in tumor biology after PST are an early phenomenon; so, an additional core biopsy performed after 14 days from treatment start should be considered in clinical trials.

Proposals for uniform collection of biospecimens from neoadjuvant breast cancer clinical trials: timing and specimen types

In this Personal View, we outline proposals for uniform collection of biospecimens obtained in neoadjuvant breast cancer trials undertaken by the Breast International Group (BIG) and the National Cancer Institute-sponsored North American Breast Cancer Group (NABCG). These proposals aim to standardise collection of high-quality specimens, with respect to both type and timing, to enhance and allow integration of results obtained from neoadjuvant trials done by several groups. They should be considered in parallel with recommendations for tissue-specimen collection and handling previously developed by BIG and NABCG. We propose that tumour tissue (formalin-fixed, paraffin-embedded and samples dedicated for molecular studies) should be taken at baseline, 1-3 weeks after the start of treatment, and at definitive surgery, with clear prioritisation in the study protocol of number, order, and preservation of samples to be gathered. This step should be accompanied by blood collection (plasma, serum, and whole blood) whenever possible. We advocate strongly a move towards one diagnostic and research biopsy procedure in all women with breast cancers potentially suitable for neoadjuvant treatment. If possible, patients should be referred at the outset to specialised centres to give them the opportunity to participate in neoadjuvant clinical trials, thereby avoiding several biopsy procedures.

EMT is the dominant program in human colon cancer

BACKGROUND

Colon cancer has been classically described by clinicopathologic features that permit the prediction of outcome only after surgical resection and staging.

METHODS

We performed an unsupervised analysis of microarray data from 326 colon cancers to identify the first principal component (PC1) of the most variable set of genes. PC1 deciphered two primary, intrinsic molecular subtypes of colon cancer that predicted disease progression and recurrence.

RESULTS

Here we report that the most dominant pattern of intrinsic gene expression in colon cancer (PC1) was tightly correlated (Pearson R = 0.92, P < 10(-135)) with the EMT signature-- both in gene identity and directionality. In a global micro-RNA screen, we further identified the most anti-correlated microRNA with PC1 as MiR200, known to regulate EMT.

CONCLUSIONS

These data demonstrate that the biology underpinning the native, molecular classification of human colon cancer--previously thought to be highly heterogeneous-- was clarified through the lens of comprehensive transcriptome analysis.

Comparison of prognostic gene expression signatures for breast cancer

BACKGROUND

During the last years, several groups have identified prognostic gene expression signatures with apparently similar performances. However, signatures were never compared on an independent population of untreated breast cancer patients, where risk assessment was computed using the original algorithms and microarray platforms.

RESULTS

We compared three gene expression signatures, the 70-gene, the 76-gene and the Gene expression Grade Index (GGI) signatures, in terms of predicting distant metastasis free survival (DMFS) for the individual patient. To this end, we used the previously published TRANSBIG independent validation series of node-negative untreated primary breast cancer patients. We observed agreement in prediction for 135 of 198 patients (68%) when considering the three signatures. When comparing the signatures two by two, the agreement in prediction was 71% for the 70- and 76-gene signatures, 76% for the 76-gene signature and the GGI, and 88% for the 70-gene signature and the GGI. The three signatures had similar capabilities of predicting DMFS and added significant prognostic information to that provided by the classical parameters.

CONCLUSION

Despite the difference in development of these signatures and the limited overlap in gene identity, they showed similar prognostic performance, adding to the growing evidence that these prognostic signatures are of clinical relevance.

Clinical application of the 70-gene profile: the MINDACT trial

The 70-gene profile is a new prognostic tool that has the potential to greatly improve risk assessment and treatment decision making for early breast cancer. Its prospective validation is currently ongoing through the MINDACT (Microarray in Node-Negative Disease May Avoid Chemotherapy) trial, a 6,000-patient randomized, multicentric trial. This article reviews the several steps in the development of the profile from its discovery to its clinical validation.

The MINDACT trial: the first prospective clinical validation of a genomic tool

One of the main challenges in oncology today has become to distinguish accurately between those patients who need adjuvant treatment and those who do not. This, together with the identification of the best type of therapy for the individual patient and the development of drugs targeting specific characteristics of tumour cells, are the goals of treatment tailoring or personalized medicine. The MINDACT trial (Microarray In Node negative Disease may Avoid ChemoTherapy) was recently launched with the aim of prospectively validating the superior performance of a new prognostic RNA-based tool--the Amsterdam 70-gene profiler MammaPrint, in order to implement its use in clinical practice later on. This manuscript shortly reviews the rational, design and logistics of MINDACT.

Effect of chest X-rays on the risk of breast cancer among BRCA1/2 mutation carriers in the international BRCA1/2 carrier cohort study: a report from the EMBRACE, GENEPSO, GEO-HEBON, and IBCCS Collaborators' Group

PURPOSE

Women who carry germline mutations in the BRCA1 and BRCA2 genes are at greatly increased risk of breast cancer (BC). Numerous studies have shown that moderate to high doses of ionizing radiation are a risk factor for BC. Because of the role of the BRCA proteins in DNA repair, we hypothesized that BRCA carriers might be more sensitive to ionizing radiation than women in the general population.

PATIENTS AND METHODS

A retrospective cohort study of 1,601 female BRCA1/2 carriers was performed. Risk of breast cancer from exposure to chest x-rays, as assessed by questionnaire data, was analyzed using a weighted Cox proportional hazards model.

RESULTS

In this cohort, any reported exposure to chest x-rays was associated with an increased risk of BC (hazard ratio [HR] = 1.54; P = .007). This risk was increased in carrier women aged 40 years and younger (HR = 1.97; P < .001) and in women born after 1949 (HR = 2.56; P < .001), particularly those exposed only before the age of 20 years (HR = 4.64; P < .001).

CONCLUSION

In our series of BRCA carriers, we detected a relatively large effect on BC risk with a level of radiation exposure that is at least an order of magnitude lower than in previously studied medical radiation-exposed cohorts. Although part of this increase may be attributable to recall bias, the observed patterns of risk in terms of age at exposure and attained age are consistent with those found in previous studies. If confirmed, the results have important implications for the use of x-ray imaging in young BRCA1/2 carriers.

Mortality after bilateral salpingo-oophorectomy in BRCA1 and BRCA2 mutation carriers: a prospective cohort study

BACKGROUND

Bilateral prophylactic salpingo-oophorectomy (BPSO) is used widely used to reduce the risk of breast and ovarian cancer in women with BRCA1 and BRCA2 mutations. However, the reduction in mortality after this surgery is unclear. We aimed to assess whether BPSO improves overall mortality or cancer-specific mortality in BRCA1 and BRCA2 mutation carriers.

METHODS

We identified a prospective cohort of 666 women with disease-associated germline mutations in BRCA1 or BRCA2 and no previous cancer diagnosis. In our primary analysis, we compared 155 women who had had BPSO and 271 women matched for age at BPSO who had not had BPSO. In our secondary analysis, we compared 188 women who had had BPSO with 478 women who had not. In both analyses, we compared overall mortality and cancer-specific mortality. All analyses were adjusted for centre, mutation (BRCA1 vs BRCA2), and birth year.

FINDINGS

In the primary analysis, mean follow-up from BPSO to censoring was 3.1 years [SD 2.4] in the BPSO group and 2.1 years [2.0] in the non-BPSO group. The hazard ratio (HR) for overall mortality was 0.24 (95% CI 0.08-0.71), for breast-cancer-specific mortality was 0.10 (0.02-0.71), and for ovarian-cancer-specific mortality was 0.05 (0.01-0.46) for women who had BPSO compared with those who had not. In secondary analysis, BPSO was associated with reduced overall mortality (HR 0.28 [95% CI 0.10-0.74]), but not with breast-cancer-specific mortality (0.15 [0.02-1.18] or ovarian-cancer-specific mortality (0.23 [0.02-1.87]. When regarded as a time-dependent covariate, BPSO was not associated significantly with mortality.

INTERPRETATION

If confirmed, the finding that BPSO improves overall survival and cancer-specific survival in women with BRCA mutations will complement our existing knowledge of cancer-risk reduction associated with BPSO. Together, these data could give information to women who are considering genetic testing.

Withdrawal from genetic counselling for cancer

BACKGROUND

A substantial minority of individuals who initially apply for genetic counselling for breast/ovarian cancer withdraw at an early stage from the counselling process. This study investigated the self-reported reasons for early withdrawal and the factors associated significantly with such withdrawal.

METHODS

Self-report questionnaires were mailed to 83 women who had applied for genetic counselling for breast/ovarian cancer but who subsequently withdrew from the counselling process (the "withdrawers"). A comparison group of 105 women who had completed the genetic counselling (the "attendees") received a similar questionnaire. The questionnaire assessed sociodemographic characteristics, reasons for applying for genetic counselling, general distress (MHI-5), cancer-specific distress (IES), and cancer worries. For those women who discontinued the counselling, reasons for withdrawal were also assessed.

RESULTS

The primary reasons given for withdrawing from counselling were difficulties in anticipating the consequences of genetic counselling (28%), and worries about being unable to adequately cope with an unfavourable test result (20%). Compared to the attendees, the withdrawers were significantly younger, more frequently asymptomatic, more often the first and only member of the family to apply for counselling, and less worried about cancer. Current levels of cancer-specific distress and general distress were comparable between the two groups.

CONCLUSION

Younger women, those without a history of cancer, and those who are first in their family to apply are more likely to withdraw prematurely from genetic counselling for breast/ovarian cancer. These withdrawers have no elevated levels of distress. However, a substantial percentage of individuals discontinue counselling due to concerns about their (in)ability to cope with a possible unfavourable test outcome. This suggests that greater attention should be paid to ways of coping with test results during the very first contact with the clinic.

Prophylactic oophorectomy in carriers of BRCA1 or BRCA2 mutations

BACKGROUND

Data concerning the efficacy of bilateral prophylactic oophorectomy for reducing the risk of gynecologic cancer in women with BRCA1 or BRCA2 mutations are limited. We investigated whether this procedure reduces the risk of cancers of the coelomic epithelium and breast in women who carry such mutations.

METHODS

A total of 551 women with disease-associated germ-line BRCA1 or BRCA2 mutations were identified from registries and studied for the occurrence of ovarian and breast cancer. We determined the incidence of ovarian cancer in 259 women who had undergone bilateral prophylactic oophorectomy and in 292 matched controls who had not undergone the procedure. In a subgroup of 241 women with no history of breast cancer or prophylactic mastectomy, the incidence of breast cancer was determined in 99 women who had undergone bilateral prophylactic oophorectomy and in 142 matched controls. The length of postoperative follow-up for both groups was at least eight years.

RESULTS

Six women who underwent prophylactic oophorectomy (2.3 percent) received a diagnosis of stage I ovarian cancer at the time of the procedure; two women (0.8 percent) received a diagnosis of papillary serous peritoneal carcinoma 3.8 and 8.6 years after bilateral prophylactic oophorectomy. Among the controls, 58 women (19.9 percent) received a diagnosis of ovarian cancer, after a mean follow-up of 8.8 years. With the exclusion of the six women whose cancer was diagnosed at surgery, prophylactic oophorectomy significantly reduced the risk of coelomic epithelial cancer (hazard ratio, 0.04; 95 percent confidence interval, 0.01 to 0.16). Of 99 women who underwent bilateral prophylactic oophorectomy and who were studied to determine the risk of breast cancer, breast cancer developed in 21 (21.2 percent), as compared with 60 (42.3 percent) in the control group (hazard ratio, 0.47; 95 percent confidence interval, 0.29 to 0.77).

CONCLUSIONS

Bilateral prophylactic oophorectomy reduces the risk of coelomic epithelial cancer and breast cancer in women with BRCA1 or BRCA2 mutations.

Effects of oral administration of N-acetyl-L-cysteine: a multi-biomarker study in smokers

N-Acetyl-L-cysteine (NAC) has been shown to exert cancer-protective mechanisms and effects in experimental models. We report here the results of a randomized, double-blind, placebo-controlled, Phase II chemoprevention trial with NAC in healthy smoking volunteers. The subjects were supplemented daily with 2 x 600 mg of oral tablets of NAC (n = 20) or placebo (n = 21) for a period of 6 months, and internal dose markers [plasma and bronchoalveolar lavage (BAL) fluid cotinine, urine mutagenicity], biologically effective dose markers [smoking-related DNA adducts and hemoglobin (Hb) adducts], and biological response markers (micronuclei frequency and antioxidants scavenging capacity) were assessed at both pre- and postsupplementation times (T(0) and T(1), respectively). Overall, the internal dose markers remained unchanged at T(1) as compared with T(0) in both NAC and placebo groups. When quantifying the biologically effective dose markers, we observed an inhibitory effect of NAC toward the formation of lipophilic-DNA adducts (5.18 +/- 0.73 versus 4.08 +/- 1.03/10(8) nucleotides; mean +/- SE; P = 0.05) as well as of 7,8-dihydro-8-oxo-2'-deoxyguanosine adducts in BAL cells (3.9 +/- 0.6 versus 2.3 +/- 0.2/10(5) nucleotides; P = 0.003). There was no effect of NAC on the formation of lipophilic-DNA adducts in peripheral blood lymphocytes or polycyclic aromatic hydrocarbon-DNA adducts in mouth floor/buccal mucosa cells or 4-aminobiphenyl-Hb adducts. Likewise, quantification of the biological response markers showed an inhibitory effect of NAC on the frequency of micronuclei in mouth floor and in soft palate cells (1.3 +/- 0.2 versus 0.9 +/- 0.2; P = 0.001) and a stimulating effect of NAC on plasma antioxidant scavenging capacity (393 +/- 14 versus 473 +/- 19 microM Trolox; P = 0.1) but not on BAL fluid antioxidant scavenging capacity. We conclude that NAC has the potential to impact upon tobacco smoke carcinogenicity in humans because it can modulate certain cancer-associated biomarkers in specific organs.