Prognostic risk factors for treatment decision in pT1a,b N0M0 HER2-positive breast cancers

Multiple metastases of human epidermal growth factor receptor 2‑positive, hormone receptor‑positive, pT1a pN0 breast cancer within 1 year after surgery: A case report

Adjuvant chemotherapy is usually not considered for pT1a pN0 human epidermal growth factor receptor 2 (HER2)-positive breast cancer due to its low recurrence rate. The present report describes a case of pT1a hormone receptor-positive HER2-positive breast cancer with multiple recurrences in the axillary lymph nodes and liver within 1 year after radical surgery. A 58-year-old woman underwent left total mastectomy and sentinel lymph node biopsy for left breast cancer with pathological stage IA (pT1a pN0). The subtype corresponded to luminal B-like breast cancer with a nuclear grade of 3 and a Ki-67 labeling index of 37%. An aromatase inhibitor (letrozole) was planned to be administered for 5 years after surgery, but the patient was diagnosed with multiple liver and axillary lymph node metastases 11 months after surgery. After 1 year of chemotherapy (paclitaxel) in combination with anti-HER2 therapy (pertuzumab and trastuzumab), liver metastases resolved. A complete response of the liver lesion has been maintained 4 years after the anti-HER2 therapy initiation. The present case exhibited two poor prognostic factors: High Ki-67 labeling index and nuclear grade 3. Based on the 'Predict' tool, the present case would be expected to have a cancer-related mortality rate of 6% 10 years after surgery with adjuvant endocrine therapy. Although this value may be controversial for postoperative anti-HER2 therapy, the present case should not be considered to be a low-risk case. When the identification of high-risk pT1a pN0 HER2-positive breast cancer is possible, postoperative anti-HER2 therapy plus chemotherapy would be effective in decreasing the rate of recurrence.

Female breast cancer subtypes in the Romagna Unit of the Emilia-Romagna cancer registry, and estimated incident cases by subtypes and age in Italy in 2020

PURPOSE

The aim of this study was to estimate the Italian burden of incident breast cancer (BC) by subtypes, according to the distribution of hormonal receptor (HR) status and expression of human epidermal growth factor 2 (HER2).

METHODS

Female breast cancers incidence in the Romagna Unit of the Emilia-Romagna registry (n. 10,711) were grouped into: HR+ /HER2-, HR+ /HER2+ , HR-/HER2+ , HR-/HER2- and missing, and by age: < 50, 50-69 and 70+ years. Data were compared with other published Italian population-bases series before using them for national estimates. We used national and regional numbers of expected breast cancers published by the Italian network of cancer registries considering the age- and geographic-specific variation of the Italian population.

RESULTS

Overall, 70.7% of incident BC cases are expected to be HR+ /HER2-, 8.5% HR+ /HER2+ , 7.5% HR-/HER2-, 4.1% HR-/HER2+ and 9.3% missing. The global ranking is similar across age-groups but with age-specific differences. The proportion of missing was around 3-times lower than in the other Italian published population-based series and similar to the SEER one. In Italy, are estimated 38,841 HR+ /HER2- breast cancer cases, 4665 HR+ /HER2+ , 4098 HR-/HER2-, 2281 HR-/HER2+ , and 5092 not specified. Numbers by age-group were provided.

CONCLUSIONS

The present estimates relied on high-quality population-based data and provide a clinically relevant information on the burden of breast cancer subtypes. These data will support the planning of therapy needs for oncologists, decision-makers, and all other stakeholders.

Clinicopathologic features of unexpectedly HER2 positive breast carcinomas: An institutional experience

Human epidermal growth factor receptor 2 (HER2) overexpression occurs in 15-20 % of all breast carcinomas. These tumors are usually high-grade which often correlates with reduced overall survival and increased rates of recurrence. In a retrospective review, we identified 19 cases of unexpectedly HER2 positive (by immunohistochemistry and/or fluorescence in-situ hybridization) invasive breast carcinomas on core needle biopsies from a registry at Northwestern Memorial Hospital. These cases included low-grade tumors, invasive lobular carcinomas, classic type, and invasive carcinomas with special subtype features. Twelve of the tumors were histologic grade 1 and 7 were histologic grade 2. One of the grade 1 tumors had tubular features (8 %), 1 had cribriform features (8 %), 2 had mucinous features (17 %), 2 were invasive lobular carcinomas, classic type (17 %), and the rest were invasive carcinoma, no special type (50 %). The histologic grade 2 tumors included 5 invasive lobular carcinomas, classic type (71 %) and 2 invasive ductal carcinomas with mucinous features (29 %). By immunohistochemistry, 13 (65 %) were HER2 score 3+, 7 were score 2+ (35 %), and reflex fluorescence in-situ hybridization (FISH) testing showed amplification in 6 cases, with 1 equivocal case amplified on excision. Despite the HER2 positive status in the selected cases, no unique morphologic features that would indicate aggressive behavior were identified. In clinical follow up, two patients were found to have recurrences, five had lymph node metastasis, and one had distant metastasis. None of the patients with recurrent disease were treated with trastuzumab, despite their positive HER2 results. These findings support that our population of HER2 positive carcinomas showed a similar rate of lymph node metastases and recurrence as poorly-differentiated tumors, supporting HER2 positivity as a poor prognostic indicator, irrespective of morphologic features. We recommend continuing to test all breast cancers, regardless of grade or special subtype features, to provide the most comprehensive treatment and prognostic information for both clinicians and patients.

Role of innate and adaptive immunity in the efficacy of anti-HER2 monoclonal antibodies for HER2-positive breast cancer

Anti-HER2 monoclonal antibodies (mAbs) such as trastuzumab are effective for all stages of HER2-positive breast cancer (BC). However, intrinsic or acquired resistance to these drugs may occur in a significant number of patients (pts) and, except for HER2 status, no validated predictive factors of response/resistance have been identified to date. This lack is in part due to the not yet fully elucidated mechanism of action of mAbs in vivo. Increasing evidence suggests a significant contribution of both innate and adaptive immunity to the antitumor effects of mAbs. The aim of this review was to describe the role of innate and adaptive immunity in the efficacy of anti-HER2 mAbs and to report known and novel strategies to be used for optimizing immune effects of anti-HER2 therapies for HER2-positive BC.

Clinico-Immunological Profile of a 67-Year-Old Woman Affected by HER2-Positive Breast Cancer and Autoimmune Dermatomyositis

A patient with HER2-positive early breast cancer (BC) developed dermatomyositis (DM), which disappeared after the first administration of adjuvant trastuzumab. No HER2 overexpression/amplification was observed in DM skin biopsies. Both BC and skin immune infiltrates were composed mostly of CD3+ T-lymphocytes. Interestingly, tumor-infiltrating lymphocytes expressed PD-1, which was negligible in skin-infiltrating lymphocytes, while both BC cells and keratinocytes were PD-L1-positive. High serum levels of endogenous anti-HER2 antibodies were detected, confirming the induction of a HER2-specific adaptive immune response. It may be argued that HER2-specific T-lymphocytes cross-reacted with one or more unknown skin antigens, causing DM. Trastuzumab may have silenced skin cross-reaction by eliminating any residual HER2-positive micrometastatic disease and, thus, inducing DM remission.

Would 1.0 cm be a more suitable cutoff to subdivide pT1 tumors in hormone receptor-negative and HER2-positive breast cancer?

BACKGROUND

HER2+ and hormone receptor (HoR)-negative breast cancer usually associated with poor outcome. However, it remained elusive for the prognosis of small (T1a-T1c) HER2+/HoR- breast cancer. The present study retrospectively analyzed the Surveillance, Epidemiology, and End Results (SEER) database to explore the clinicopathological characteristics and prognosis of T1a-T1c HER2+/HoR- breast cancer.

MATERIAL AND METHODS

Data for patients diagnosed with either HER2-/HoR+or HER2+/HoR- T1a-T1c breast cancer between 2010 and 2012 were obtained from SEER program. Survival analyses were conducted by Kaplan-Meier method and Cox proportion hazard regression.

RESULTS

Totally, 2648 HER2+/HoR- and 56387 HER2-/HoR+T1a-T1c breast cancer patients were enrolled. There was a clear trend that tumor size had a positive correlation with advanced AJCC stage (P < 0.001) and N-stage (P < 0.001). T1a and T1b HER2+/HoR- breast cancer had great homogeneity in that these two subgroups had comparable survival and both showed no significant survival difference with its counterpart of HER2-/HoR+subtype. Conversely, T1c HER2+/HoR- breast cancers revealed worse prognosis than T1a/T1b HER2+/HoR- and T1c HER2-/HoR+tumors (BCSS HR 3.847, P < 0.001; OS HR 2.055, P < 0.001).

CONCLUSION

T1a and T1b HER2+/HoR- breast cancer had favorable prognosis and great homogeneity, indicating 1.0 cm may be a suitable cutoff for subclassification of T1 cancer. Future randomized clinical trials were warranted to verify this hypothesis and elucidate the biological behavior of small T1 tumor to facilitate precise medicine.

Prognostic impact of interval breast cancer detection in women with pT1a N0M0 breast cancer with HER2-positive status: Results from a multicentre population-based cancer registry study

BACKGROUND

Although human epidermal growth factor receptor 2 (HER2) overexpression is associated with poor prognosis, patients (pts) with pT1a N0M0 breast cancers (BCs) have an excellent outcome across all subtypes. Interval cancers (ICs) have poorer survival than screen-detected (SD) tumours, and an association has been reported between ICs and HER2 overexpression. We aimed to determine, in a general population of pT1a N0M0 BCs with known screening status, whether HER2-positive ICs have a poorer outcome than HER2-positive SD cancers.

METHODS

We evaluated all incident pT1a N0M0 BCs (n = 874) collected in the Emilia-Romagna region (Italy) from 2003 to 2009 and diagnosed in women aged 50-69. Pts unexposed to screening, with unknown HER2 status and/or treated with adjuvant trastuzumab were excluded from analysis.

RESULTS

Sixty-one percent of the BCs were SD, whereas 19% were ICs. BCs with high histologic grade, hormone receptor-negative or HER2-positive status (odds ratio=1.7; 95% confidence interval [CI]: 1.1-2.7) were more likely ICs. Median follow-up was 115 months. The 10-year invasive disease-free survival (iDFS) for HER2-positive ICs was lower than that for HER2-positive SD cancers: 75.0% (95% CI: 55.5%-94.5%) versus 93.8% (95% CI: 86.5%-100%). An interaction between ICs and HER2-positive status was found for poorer iDFS after adjusting for prognostic variables (HR = 5.3; 95% CI: 1.6-16.7).

CONCLUSIONS

IC detection may identify pts with HER2-positive pT1a N0M0 tumours in whom the rate of recurrence justifies consideration for conventional, anti-HER2, adjuvant treatment.

Adjuvant trastuzumab: a 10-year overview of its benefit

INTRODUCTION

Anti-HER2 targeted therapy is one of the key advances in the treatment of breast cancer that have occurred in the last 20 years. In the adjuvant setting, the use of trastuzumab has led to prolonged and sustained survival benefit with very little toxicity as also confirmed by the 10-year follow-up results from the pivotal trials. Despite the survival improvement, several key issues are not entirely resolved in this field. These issues have led to multiple research efforts in de-escalating or escalating the standard treatment with chemotherapy and 1 year of adjuvant trastuzumab. Areas covered: In this paper, we present an in depth overview on the state of the art on these key issues of refining decision-making in adjuvant anti-HER2 therapy. Expert commentary: Despite many important research efforts in the field, chemotherapy plus trastuzumab for a total duration of 1 year remains the standard of care. However, recent data showed that besides standard anthracycline- and taxane-based cytotoxic therapy, alternative chemotherapy regimens can now be proposed to patients with small tumors without nodal involvement and to women at high-risk of developing cardiotoxicity. Of note, besides HER2 itself, biomarkers predicting patients who may truly benefit from anti-HER2 agents are still lacking.

Immunoglobulin G fragment C receptor polymorphisms and efficacy of preoperative chemotherapy plus trastuzumab and lapatinib in HER2-positive breast cancer

Lapatinib enhances antibody-dependent cell-mediated cytotoxicity (ADCC) activity of trastuzumab. FcγR polymorphisms have been associated with both ADCC and clinical activity of trastuzumab in HER2+ breast cancer (BC) patients (pts). We analyzed FcγRIIa-H131R and FcγRIIIa-V158F polymorphisms in the CHER-LOB trial population of HER2+ BCs treated with preoperative chemotherapy plus trastuzumab (arm A), lapatinib (arm B) or both (arm C). Genotyping was successfully performed in 73/121 (60%) pts. A significant improvement in pathological complete response (pCR) rate was observed for the combination arm C, but only in FcγRIIIa V allele carriers (C vs A, 67 vs 27%, P=0.043; C vs B, 67 vs 22%, P=0.012). An independent interaction between arm C and FcγRIIIa V allele was found for pCR (odds ratio=9.4; 95% confidence interval, 2.3-39.6; P=0.003). No significant associations were observed between pCR and FcγRIIa polymorphism, and between pre-treatment tumor-infiltrating lymphocytes and FcγR polymorphisms. Our study provides evidence for a FcγRIIIa V allele-restricted pCR benefit from neoadjuvant trastuzumab plus lapatinib in HER2+ BC.

The effect of trastuzumab-based chemotherapy in small node-negative HER2-positive breast cancer

The prognosis of patients with stage II-III Human Epidermal growth factor Receptor 2 (HER2)-positive breast cancer has significantly improved since the addition of trastuzumab to (neo-)adjuvant chemotherapy. Several reports have shown that small (≤2 cm), node-negative, HER2-positive tumors have a relatively poor prognosis and these patients increasingly receive trastuzumab-based chemotherapy. We aimed to provide evidence for this approach in a population-based cohort. All T1N0M0 HER2-positive breast cancer patients diagnosed between 2006 and 2012 were identified from the Netherlands Cancer Registry. Patient, tumor, and treatment characteristics were recorded. Kaplan-Meier statistics were used for overall survival (OS) and breast cancer-specific survival (BCSS) estimations overall and in T1a, T1b, and T1c tumors separately. Cox regression analyses were performed to account for imbalances in baseline characteristics between treated and untreated patients. A total of 3512 patients were identified: 385 with T1a, 800 with T1b, and 2327 with T1c tumors. Forty-five percent of patients received chemotherapy and/or trastuzumab: 92 % received both. Chemotherapy and/or trastuzumab significantly improved 8-year OS (95 vs. 84 %; hazard ratio [HR] 0.29; 95 % confidence interval [CI] 0.21-0.41, P < 0.001). The effect remained significant in multivariable analyses (HR 0.35; 95 % CI 0.23-0.52, P < 0.001). BCSS was also improved with systemic treatment in univariable (96 vs. 92 %; HR 0.41; 95 % CI 0.27-0.63, P < 0.001) and multivariable analyses (HR 0.31; 95 % CI 0.19-0.53, P < 0.001). Treatment effect on OS and BCSS was similar in T1a, T1b, and T1c tumors. Chemotherapy and/or trastuzumab improves OS and BCSS and can be considered in all patients with small node-negative HER2-positive breast cancer.