To update key recommendations of the American Society of Clinical Oncology/College of American Pathologists estrogen (ER) and progesterone receptor (PgR) testing in breast cancer guideline.
A ...multidisciplinary international Expert Panel was convened to update the clinical practice guideline recommendations informed by a systematic review of the medical literature.
The Expert Panel continues to recommend ER testing of invasive breast cancers by validated immunohistochemistry as the standard for predicting which patients may benefit from endocrine therapy, and no other assays are recommended for this purpose. Breast cancer samples with 1% to 100% of tumor nuclei positive should be interpreted as ER positive. However, the Expert Panel acknowledges that there are limited data on endocrine therapy benefit for cancers with 1% to 10% of cells staining ER positive. Samples with these results should be reported using a new reporting category, ER Low Positive, with a recommended comment. A sample is considered ER negative if < 1% or 0% of tumor cell nuclei are immunoreactive. Additional strategies recommended to promote optimal performance, interpretation, and reporting of cases with an initial low to no ER staining result include establishing a laboratory-specific standard operating procedure describing additional steps used by the laboratory to confirm/adjudicate results. The status of controls should be reported for cases with 0% to 10% staining. Similar principles apply to PgR testing, which is used primarily for prognostic purposes in the setting of an ER-positive cancer. Testing of ductal carcinoma in situ (DCIS) for ER is recommended to determine potential benefit of endocrine therapies to reduce risk of future breast cancer, while testing DCIS for PgR is considered optional. Additional information can be found at www.asco.org/breast-cancer-guidelines.
Learning Objectives
Contrast the definitions of TN and basal‐like.
Describe the undistinguishable global gene expression patterns of non‐basal‐like TN tumors versus non‐TN tumors that are ...non‐basal‐like.
Describe the relationship between TN heterogeneity and tumor heterogeneity plus microenvironmental heterogeneity.
Triple‐negative (TN) and basal‐like (BL) breast cancer definitions have been used interchangeably to identify breast cancers that lack expression of the hormone receptors and overexpression and/or amplification of HER2. However, both classifications show substantial discordance rates when compared to each other. Here, we molecularly characterize TN tumors and BL tumors, comparing and contrasting the results in terms of common patterns and distinct patterns for each. In total, when testing 412 TN and 473 BL tumors, 21.4% and 31.5% were identified as non‐BL and non‐TN, respectively. TN tumors identified as luminal or HER2‐enriched (HER2E) showed undistinguishable overall gene expression profiles when compared versus luminal or HER2E tumors that were not TN. Similar findings were observed within BL tumors regardless of their TN status, which suggests that molecular subtype is preserved regardless of individual marker results. Interestingly, most TN tumors identified as HER2E showed low HER2 expression and lacked HER2 amplification, despite the similar overall gene expression profiles to HER2E tumors that were clinically HER2‐positive. Lastly, additional genomic classifications were examined within TN and BL cancers, most of which were highly concordant with tumor intrinsic subtype. These results suggest that future clinical trials focused on TN disease should consider stratifying patients based upon BL versus non‐BL gene expression profiles, which appears to be the main biological difference seen in patients with TN breast cancer.
摘要
三阴性（TN）乳腺癌与基底细胞样（BL）乳腺癌的定义一直混用，意指激素受体表达、HER2过度表达和/或扩增缺乏的乳腺癌。然而，当对这两种分类进行互相比较时，却差异巨大。因此，本文从分子角度概括TN和BL肿瘤的特征，对其共同的特征和二者之间的区别进行比较和对照。共检验了412例TN和473例BL肿瘤，其中确认为非BL和非TN肿瘤分别占21.4%和31.5%。确认为管腔型或HER2富集（HER2E）型的TN肿瘤在总基因表达谱上与管腔型或HER2E型非TN肿瘤无法鉴别。在BL肿瘤中也有类似发现，与TN状态无关，提示分子亚型与肿瘤个体的标记物结果无关。有趣的是，大多数确认为HER2E的TN肿瘤HER2表达低下且缺乏HER2扩增，但其总基因表达谱与临床HER2阳性的HER2E肿瘤相似。最后，对TN和BL乳腺癌的基因组分类进行了追查，结果发现大多数基因组分类与肿瘤固有亚型高度一致。上述结果提示：鉴于基因表达谱似为TN乳腺癌患者的主要生物学差异，因此，今后的TN疾病临床试验应考虑使用BL/非BL肿瘤的基因表达谱对患者进行分层。
Triple‐negative breast cancer is a broad and diverse category for which additional subclassifications are needed. Therefore, future clinical trials should stratify patients based on a tumor′s basal‐like versus non‐basal‐like gene expression profile, which appears to be the main biological difference seen within triple‐negative breast cancer.
Triple-negative breast cancer (TNBC) is an operational term that refers to a heterogeneous collection of breast cancers lacking expression of estrogen receptor (ER), progesterone receptor, and HER2. ...These tumors account for 12–17 % of all breast cancers, preferentially affect young women, are more frequent in women of African and Hispanic descent, and are enriched in the population of patients diagnosed with “interval cancers.” TNBCs account for the majority of breast cancers arising in
BRCA1
germline mutation carriers (approximately 80 %), and approximately 11–16 % of all TNBCs harbor
BRCA1
or
BRCA2
germline mutations. Well-known risk factors for ER-positive cancers, such as reproductive history and hormonal factors, do not appear to have the same correlations for TNBC, and histologic risk factors for TNBC have not been identified. Patients with TNBC have a higher risk of both local and distant recurrence, but this is not mitigated by bigger surgery, and standard criteria should be used to select the approach to local therapy in these patients. Although platinum drugs have shown promise in the treatment of TNBC, standard chemotherapy remains the standard of care outside of a clinical trial.
To update key recommendations of the American Society of Clinical Oncology/College of American Pathologists estrogen receptor (ER) and progesterone receptor (PgR) testing in breast cancer guideline.
...A multidisciplinary international Expert Panel was convened to update the clinical practice guideline recommendations informed by a systematic review of the medical literature.
The Expert Panel continues to recommend ER testing of invasive breast cancers by validated immunohistochemistry as the standard for predicting which patients may benefit from endocrine therapy, and no other assays are recommended for this purpose. Breast cancer samples with 1% to 100% of tumor nuclei positive should be interpreted as ER positive. However, the Expert Panel acknowledges that there are limited data on endocrine therapy benefit for cancers with 1% to 10% of cells staining ER positive. Samples with these results should be reported using a new reporting category, ER Low Positive, with a recommended comment. A sample is considered ER negative if < 1% or 0% of tumor cell nuclei are immunoreactive. Additional strategies recommended to promote optimal performance, interpretation, and reporting of cases with an initial low to no ER staining result include establishing a laboratory-specific standard operating procedure describing additional steps used by the laboratory to confirm/adjudicate results. The status of controls should be reported for cases with 0% to 10% staining. Similar principles apply to PgR testing, which is used primarily for prognostic purposes in the setting of an ER-positive cancer. Testing of ductal carcinoma in situ (DCIS) for ER is recommended to determine potential benefit of endocrine therapies to reduce risk of future breast cancer, while testing DCIS for PgR is considered optional. Additional information can be found at www.asco.org/breast-cancer-guidelines .
To develop guideline recommendations concerning optimal neoadjuvant therapy for breast cancer.
ASCO convened an Expert Panel to conduct a systematic review of the literature on neoadjuvant therapy ...for breast cancer and provide recommended care options.
A total of 41 articles met eligibility criteria and form the evidentiary basis for the guideline recommendations.
Patients undergoing neoadjuvant therapy should be managed by a multidisciplinary care team. Appropriate candidates for neoadjuvant therapy include patients with inflammatory breast cancer and those in whom residual disease may prompt a change in therapy. Neoadjuvant therapy can also be used to reduce the extent of local therapy or reduce delays in initiating therapy. Although tumor histology, grade, stage, and estrogen, progesterone, and human epidermal growth factor receptor 2 (HER2) expression should routinely be used to guide clinical decisions, there is insufficient evidence to support the use of other markers or genomic profiles. Patients with triple-negative breast cancer (TNBC) who have clinically node-positive and/or at least T1c disease should be offered an anthracycline- and taxane-containing regimen; those with cT1a or cT1bN0 TNBC should not routinely be offered neoadjuvant therapy. Carboplatin may be offered to patients with TNBC to increase pathologic complete response. There is currently insufficient evidence to support adding immune checkpoint inhibitors to standard chemotherapy. In patients with hormone receptor (HR)-positive (HR-positive), HER2-negative tumors, neoadjuvant chemotherapy can be used when a treatment decision can be made without surgical information. Among postmenopausal patients with HR-positive, HER2-negative disease, hormone therapy can be used to downstage disease. Patients with node-positive or high-risk node-negative, HER2-positive disease should be offered neoadjuvant therapy in combination with anti-HER2-positive therapy. Patients with T1aN0 and T1bN0, HER2-positive disease should not be routinely offered neoadjuvant therapy.Additional information is available at www.asco.org/breast-cancer-guidelines.
Abstract Of the estimated 1 million cases of breast cancer diagnosed annually worldwide, it is estimated that over 170,000 will harbor the triple-negative (estrogen receptor/progesterone ...receptor/HER2—negative) phenotype. Most, though not all, triple-negative breast cancers will be basal-like on gene expression micorarrays. The basal-like molecular subtype exhibits a unique molecular profile and set of risk factors, aggressive and early pattern of metastasis, limited treatment options, and poor prognosis. Large population-based studies have identified a higher proportion of triple-negative breast tumors among premenopausal African American women, and a suggestion that increased parity, younger age at first-term pregnancy, shorter duration of breast feeding, and elevated hip-to-waist ratio might be particular risk factors. When BRCA1 mutation carriers develop breast cancer, it is usually basal-like; given the central role of BRCA1 in DNA repair, this could have profound therapeutic implications. When diagnosed, triple-negative breast cancers illustrate preferential relapse in visceral organs, including the central nervous system. Although initial response to chemotherapy might be more profound, relapse is early and common among triple-negative breast cancers compared with luminal breast cancers. The armamentarium of “targeted therapeutics” for triple-negative breast cancer is evolving and includes strategies to inhibit angiogenesis, epidermal growth factor receptor, and other kinases. Finally, the positive association between triple-negative breast cancer and BRCA mutations makes inhibition of poly(adenosine diphosphate-ribose) polymerase—1 an attractive therapeutic strategy that is in active study.
Young-onset breast cancer (<40 years) is associated with worse prognosis and higher mortality. Breast cancer risk factors may contribute to distinct tumor biology and distinct age at onset, but ...understanding of these relationships has been hampered by limited representation of young women in epidemiologic studies and may be confounded by menopausal status.
We examined tumor characteristics and epidemiologic risk factors associated with premenopausal women's and young women's breast cancer in phases I-III of the Carolina Breast Cancer Study (5309 cases, 2022 control subjects). Unconditional logistic regression was used to assess heterogeneity by age (<40 vs. ≥40 years) and menopausal status.
In both premenopausal and postmenopausal strata, younger women had more aggressive disease, including higher stage, hormone receptor-negative, disease as well as increased frequency of basal-like subtypes, lymph node positivity, and larger tumors. Higher waist-to-hip ratio was associated with reduced breast cancer risk among young women but with elevated risk among older women. Parity was associated with increased risk among young women and reduced risk among older women, while breastfeeding was more strongly protective for young women. Longer time since last birth was protective for older women but not for young women. In comparison, when we stratified by age, menopausal status was not associated with distinct risk factor or tumor characteristic profiles, except for progesterone receptor status, which was more commonly positive among premenopausal women.
Age is a key predictor of breast cancer biologic and etiologic heterogeneity and may be a stronger determinant of heterogeneity than menopausal status. Young women's breast cancer appears to be etiologically and biologically distinct from that among older women.
Olaparib, a poly (ADP-ribose) polymerase (PARP) inhibitor (PARPi), is approved for the treatment of human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer (MBC) in germline ...(g)
/
mutation carriers. Olaparib Expanded, an investigator-initiated, phase II study, assessed olaparib response in patients with MBC with somatic (s)
/
mutations or g/s mutations in homologous recombination (HR)-related genes other than
2.
Eligible patients had MBC with measurable disease and germline mutations in non-
/
HR-related genes (cohort 1) or somatic mutations in these genes or
/
(cohort 2). Prior PARPi, platinum-refractory disease, or progression on more than two chemotherapy regimens (metastatic setting) was not allowed. Patients received olaparib 300 mg orally twice a day until progression. A single-arm, two-stage design was used. The primary endpoint was objective response rate (ORR); the null hypothesis (≤ 5% ORR) would be rejected within each cohort if there were four or more responses in 27 patients. Secondary endpoints included clinical benefit rate and progression-free survival (PFS).
Fifty-four patients enrolled. Seventy-six percent had estrogen receptor-positive HER2-negative disease. Eighty-seven percent had mutations in
s
/
,
or
. In cohort 1, ORR was 33% (90% CI, 19% to 51%) and in cohort 2, 31% (90% CI, 15% to 49%). Confirmed responses were seen only with g
(ORR, 82%) and s
/
(ORR, 50%) mutations. Median PFS was 13.3 months (90% CI, 12 months to not available/computable NA) for g
and 6.3 months (90% CI, 4.4 months to NA) for s
/
mutation carriers. No responses were observed with
or
mutations alone.
PARP inhibition is an effective treatment for patients with MBC and g
or s
/
mutations, significantly expanding the population of patients with breast cancer likely to benefit from PARPi beyond g
/
mutation carriers. These results emphasize the value of molecular characterization for treatment decisions in MBC.
Breast cancer metastasis remains a clinical challenge, even within a single patient across multiple sites of the disease. Genome-wide comparisons of both the DNA and gene expression of primary tumors ...and metastases in multiple patients could help elucidate the underlying mechanisms that cause breast cancer metastasis. To address this issue, we performed DNA exome and RNA sequencing of matched primary tumors and multiple metastases from 16 patients, totaling 83 distinct specimens. We identified tumor-specific drivers by integrating known protein-protein network information with RNA expression and somatic DNA alterations and found that genetic drivers were predominantly established in the primary tumor and maintained through metastatic spreading. In addition, our analyses revealed that most genetic drivers were DNA copy number changes, the TP53 mutation was a recurrent founding mutation regardless of subtype, and that multiclonal seeding of metastases was frequent and occurred in multiple subtypes. Genetic drivers unique to metastasis were identified as somatic mutations in the estrogen and androgen receptor genes. These results highlight the complexity of metastatic spreading, be it monoclonal or multiclonal, and suggest that most metastatic drivers are established in the primary tumor, despite the substantial heterogeneity seen in the metastases.
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