Genomic copy number alterations as biomarkers for triple negative pregnancy-associated breast cancer.

BACKGROUND: PABC, commonly defined as breast cancer diagnosed during or ≤ 1 year after pregnancy, accounts for 7% of all breast cancers in women ≤ 45 years. Compared to age-matched non-PABC patients, PABC is characterized by a particularly aggressive histopathologic profile with poorly differentiated and estrogen- and progesterone receptor negative tumors and associated high mortality rates. This study assessed the genomic background of triple-negative PABC tumors by detection of copy number alterations (CNAs). METHODS: MLPA was used to compare CNAs in breast cancer-associated chromosomal loci between triple-negative PABC- and subtype-matched non-PABC patients. Both CNA patterns were evaluated by cluster analysis; associations between individual gene CNAs, pathological characteristics and survival were explored. RESULTS: Triple-negative PABC tumors exhibited unique CNAs compared to non-PABC tumors, including enrichment for TOP2A copy number loss, an independent predictor of worse overall survival (HR 8.96, p = 0.020). Cluster analysis based on CNA profiles identified a triple-negative PABC-subgroup with a particularly poor prognosis, characterized by chromosome 8p copy number loss. Individual gene CNAs analysis revealed that FGFR1 copy number loss on chromosome 8p11.23 was an independent predictor of poor outcome in multivariate analysis (HR 3.59, p = 0.053) and predicted the development of distant metastases (p = 0.048). CONCLUSION: This study provides novel insights into the biology of triple-negative PABC tumors suggesting that CNAs, particularly 8p loss and TOP2A loss, are involved in the development of breast cancer during pregnancy. FGFR1 loss and TOP2A loss seem to be promising new biomarkers that independently identify subgroups of PABC patients with poor prognosis. These genomic biomarkers may provide clues for personalized therapy.

Prognosis of pregnancy-associated breast cancer: inferior outcome in patients diagnosed during second and third gestational trimesters and lactation.

PURPOSE: Pregnancy-associated breast cancer, although most commonly defined as breast cancer diagnosed during pregnancy or ≤1 year following delivery, knows a variety of definitions, likely related to the diversity of reported clinicopathological features and prognosis. More insight into the different breast cancer subgroups during pregnancy, time after delivery and the postpartum period is therefore warranted. METHODS: Patients with breast cancer diagnosed during pregnancy or ≤6 months postdelivery were included, and subdivided according to gestational trimester, and postpartum patients according to lactational status. Subgroups were compared to matched non-PABC patients, to investigate the influence of pregnancy and lactation on clinical course and outcome. RESULTS: Overall, 662 PABC patients were included (median age 34 years, median follow-up 6.5 years). PABC patients showed an advanced stage at diagnosis and an inferior 5-years-OS (75.4% vs. 83.2%, p = 0.000) compared to 1392 matched non-PABC patients. In subgroup analysis, first trimester PABC patients showed a significantly lower tumor size and stage as compared to other trimesters. Patients diagnosed during the first trimester and postpartum non-lactating patients had a relatively good OS (81.3% and 77.9%, respectively) versus patients diagnosed during the second and third trimesters and during lactation (OS 60.0%, 64.9% and 65.6%, respectively, p = 0.003). CONCLUSION: In this large (uniquely specified) PABC cohort, an inferior outcome was found for patients diagnosed within the second and third gestational trimesters and during lactation. These findings indicate that PABC is clinically a heterogeneous group of breast cancer patients that should be redefined based on trimester of diagnosis and lactational status.

Grading of invasive breast carcinoma: the way forward.

Histologic grading has been a simple and inexpensive method to assess tumor behavior and prognosis of invasive breast cancer grading, thereby identifying patients at risk for adverse outcomes, who may be eligible for (neo)adjuvant therapies. Histologic grading needs to be performed accurately, on properly fixed specimens, and by adequately trained dedicated pathologists that take the time to diligently follow the protocol methodology. In this paper, we review the history of histologic grading, describe the basics of grading, review prognostic value and reproducibility issues, compare performance of grading to gene expression profiles, and discuss how to move forward to improve reproducibility of grading by training, feedback and artificial intelligence algorithms, and special stains to better recognize mitoses. We conclude that histologic grading, when adequately carried out, remains to be of important prognostic value in breast cancer patients.

[Histopathologic grading of breast cancer; large variation with major consequences?] / Histopathologische gradering van het mammacarcinoom.

The pathologist's assessment of tumor tissue plays a critical role in therapeutic decision-making in early-stage invasive breast cancer. In daily practice, however, there appears to be considerable variation in grading between the different Dutch pathology laboratories and between individual pathologists within the same laboratory. This underlines the need to standardize grading by pathologists as much as possible in order to minimize the risk of a worse outcome for patients due to under-treatment and of unnecessary toxicity from over-treatment. Therefore, two initiatives were launched, i.e. laboratory-specific feedback reports and an e-learning module in which pathologists were trained in grading of invasive breast cancer. While these initiatives have yielded encouraging results, the overall variation in grading remains significant. Awareness of this variation, and of the inherent difficulties of subjective grading, among the various clinicians involved in breast cancer management, is therefore of utmost importance to improve clinical decision-making for patients.

Pregnancy-associated breast cancer: nationwide Dutch study confirms a discriminatory aggressive histopathologic profile.

PURPOSE: Breast cancer is the most common type of malignancy in pregnant women, occurring approximately once in every 3000 pregnancies. Pregnancy-associated breast cancer (PABC) is commonly defined as breast cancer diagnosed during or within one year after pregnancy, and it accounts for up to 6.9% of all breast cancers in women younger than 45 years old. Whether these cancers arise before or during pregnancy, and whether they are stimulated by the high hormonal environment of pregnancy, is currently unknown. This study assesses the histopathological profile of PABC in a large Dutch population-based cohort. METHODS: We identified 744 patients with PABC (in this cohort defined as breast cancer diagnosed during or within 6 months after pregnancy) diagnosed between 1988 and 2019, in the nationwide Dutch Pathology Registry (PALGA). An age-matched PALGA cohort of unselected breast cancer patients (≤ 45 years), diagnosed between 2013 and 2016, was used as a control. Histopathologic features of both cohorts were compared. RESULTS: The median age of PABC patients was 34.3 years old (range 19-45 years) and most breast cancers were diagnosed during pregnancy (74.2%). As compared to age-matched controls, PABC patients had tumors of higher Bloom-Richardson grade (grade I: 1.5% vs. 12.4%, grade II: 16.9% vs. 31.3%, grade III: 80.3% vs. 39.5%, p < 0.0001). Furthermore, estrogen (ER)- and progesterone (PR)-receptor expression was less frequently reported positive (ER: 38.9% vs. 68.2% and PR: 33.9% vs. 59.0%, p < 0.0001), while a higher percentage of PABC tumors overexpressed HER2 (20.0% vs. 10.0%, p < 0.0001). The most observed intrinsic subtype in PABC was triple-negative breast cancer (38.3% vs. 22.0%, p < 0.0001), whereas hormone-driven cancers were significantly less diagnosed (37.9% vs. 67.3%, p < 0.0001). CONCLUSION: This study, based on a large population-based cohort of 744 PABC Dutch patients, underlines the more aggressive histopathologic profile compared to age-matched breast cancer patients ≤ 45 years. Further in-depth genetic analysis will be performed to unravel the origin of this discriminating phenotype. It definitely calls for timely detection and optimal treatment of this small but delicate subgroup of breast cancer patients.

The increasing importance of histologic grading in tailoring adjuvant systemic therapy in 30,843 breast cancer patients.

PURPOSE: The large variation in histologic grading of invasive breast cancer (IBC) that has been reported likely influences tailoring adjuvant therapy. The role of grading in therapeutic decision-making in daily practice, was evaluated using the Dutch national guidelines for IBC-management. METHODS: Synoptic reports of IBC resection-specimens, obtained between 2013 and 2016, were extracted from the nationwide Dutch Pathology Registry, and linked to treatment-data from the Netherlands Cancer Registry. The relevance of grading for adjuvant chemotherapy (aCT) was quantified by identifying patients for whom grade was the determinative factor. In addition, the relation between grade and aCT-administration was evaluated by multivariate logistic regression for patients with a guideline-aCT-indication. RESULTS: 30,843 patients were included. Applying the guideline that was valid between 2013 and 2016, grade was the determinative factor for the aCT-indication in 7744 (25.1%) patients, a percentage that even increased according to the current guideline where grade would be decisive for aCT in 10,869 (35.2%) patients. Also in current practice, the indication for adjuvant endocrine therapy (aET) would be based on grade in 9173 (29.7%) patients. Finally, as patients with lower-grade tumors receive aCT significantly less often, grade was also decisive in tailoring aCT de-escalation. CONCLUSIONS: In the largest study published so far we illustrate the increasing importance of histologic grade in tailoring adjuvant systemic breast cancer therapy. Next to playing a key-role in aCT-indication and de-escalation, the role of grading has expanded to the indication for aET. Optimizing histologic grading by pathologists is urgently needed to diminish the risk of worse patient outcome due to non-optimal treatment.

Chemotherapy-induced febrile neutropenia: primary G-CSF prophylaxis indicated during docetaxel cycles.

BACKGROUND: Chemotherapy-induced febrile neutropaenia (FN) is a common and life-threatening adverse event, which can be largely prevented by the use of granulocyte colony-stimulating factor (G-CSF); G-CSF, however is expensive and not without side effects. Although primary G-CSF prophylaxis is recommended when the risk of FN is ≥ 20%, it is unclear during which cycles it should be administered. This study assessed and compared the FN incidence in the neo-adjuvant or adjuvant administration of two chemotherapy regimens that are widely used in breast cancer care to provide clinically useful recommendations for G-CSF use. METHODS: 221 breast cancer patients were included in this retrospective single-centre study. In total, 181 patients received three cycles of 5-flourouracil, epirubicin, cyclophosphamide (FEC) followed by three cycles of docetaxel (3F-3D) (81.9%); 40 patients received four cycles of doxorubicin, cyclophosphamide (AC) followed by twelve cycles of paclitaxel (4AC-12P) (18.1%). The episodes of FN, extracted from the electronic patient files, were analysed and compared. RESULTS: Overall, FN was identified in 27.8% of patients and occurred significantly more in patients receiving 3F-3D compared to patients receiving 4AC-12P (31.5% versus 10.0%, OR 4.14, 95% CI: 1.14-12.18). Comparison of FN occurrence after first exposure to FEC (6.1%), AC (5.0%), docetaxel (20.9%), or paclitaxel (0%) showed a significantly higher risk in patients receiving docetaxel than following administration of the other three agents. CONCLUSIONS: In breast cancer treatment, compared to other frequently-used agents, monotherapy with docetaxel (100 mg/m2) renders a substantial risk of FN (20.9%), thereby justifying the use of primary G-CSF according to international guidelines.