Trastuzumab in small tumours and in elderly women

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.

Membranous or Cytoplasmic HER2 Expression in Colorectal Carcinoma: Evaluation of Prognostic Value Using Both IHC & BDISH

BACKGROUND

Human epidermal growth factor recptor-2 (HER2) was identified as a driver gene in several types of cancers with both prognostic and predictive value. However, the molecular association of HER2 gene mutation with HER2 gene amplification and/or protein expression in cancer tissues has not been clearly defined. Moreover, there is little information available on HER2 status role in tumor progression and metastasis in colorectal carcinoma (CRC) compared to other solid tumors. The aim of this study was to evaluate both HER2 amplification and protein expression profiles using immunohistochemistry (IHC) and bright-field dual in situ hybridization (BDISH) techniques, respectively.

PATIENTS AND METHODS

Tissue microarray (TMA) was constructed to accommodate a total of 243 CRC formalin-fixed paraffin embedded (FFPE) samples of consent patients and stained by IHC and BDISH methods. The expression patterns of HER2 protein status were evaluated and correlated to HER2 gene amplification status and then assessed for its prognostic value.

RESULTS

The expression profile of 58% samples showed cytoplasmic expression patterns of different categories. Interestingly, only 1% showed strong (+3) membranous expression pattern of HER2 with perfect match with their corresponding gene amplification status (>2). However, the cytoplasmic HER2 protein status did not show significant correlation with most clinicopathological features and survival outcomes except with age (p = 0.04) and tumor size (p = 0.03).

CONCLUSION

We demonstrated that the membranous HER2 gene/protein status is infrequent, while the main fraction of HER2 overexpression was cytoplasmic and lacking prognostic value. This cytoplasmic HER2 overexpression was induced through a gene-amplification independent pathway, making the HER2 gene status evaluation approach in those cases not worthy. Further investigations about the molecular pathways of the cytoplasmic HER2 protein in CRC and its associations with survival outcomes are required to allow either a breakthrough in CRC management; or to confirm the hypothesis of a marginal role in CRC onset and progression.

Incidence and identification of risk factors for trastuzumab-induced cardiotoxicity in breast cancer patients: an audit of a single "real-world" setting

Management of human epidermal growth factor receptor-2-positive (HER2+) breast cancer patients includes the combination of adjuvant chemotherapy and trastuzumab. A meta-analysis reported that <5% of HER2+ breast cancer patients will develop trastuzumab-induced cardiotoxicity (TIC). Observational data suggest that incidence is much higher. We aimed to determine the incidence, time to development, and risk factors associated with TIC among less selected patients. A retrospective cohort study was carried out in 160 HER2+ breast cancer patients who received adjuvant chemotherapy with trastuzumab from January 2006 to June 2014 at St. Michael's Hospital, Toronto, Canada. Patient demographics, cardiovascular history, and TIC were recorded. TIC was defined as symptomatic (heart failure) or asymptomatic [decline in left ventricular ejection fraction (LVEF) by ≥10% or LVEF ≤ 50%]. Of the 160 patients [median age 52 (IQR 45-60), 48.1% on anthracycline-based chemotherapy], 34 patients (21.3%) experienced TIC (median follow-up 55.4 months). The median time to development of TIC was 28.5 weeks during trastuzumab therapy. Those with TIC were more likely to have undergone a mastectomy (52.9 vs. 33.3%, p = 0.04). However, after adjusting for anthracycline-based chemotherapy, and radiotherapy, mastectomy was not independently associated with TIC (HR 2.02; 95% CI 0.88-4.63). The incidence of TIC is higher in our "real-world" population compared to clinical trial data. The median time to development of TIC was 28 weeks after trastuzumab initiation, approximately the 10th treatment of trastuzumab. Timely identification and management of patients is important to avoid irreversible cardiac toxicity and improve breast cancer survival.

Trastuzumab in Human Epidermal Growth Factor Receptor 2-Positive Early Breast Cancer: Results of a Prospective, Noninterventional Study on Routine Treatment Between 2006 and 2012 in Germany

PURPOSE

Trastuzumab is part of the standard treatment in patients with human epidermal growth factor receptor 2-positive early breast cancer in addition to (neo)adjuvant chemotherapy. This German prospective noninterventional study, which included major patient cohorts underrepresented in the pivotal randomized studies, examined the generalizability of the results of those studies.

PATIENTS AND METHODS

Between 2006 and 2012, 4,027 patients were enrolled and treated with trastuzumab; they were unselected regarding age or concomitant/sequential adjuvant chemotherapy. Long-term outcome data were obtained in yearly intervals. All analyses were descriptive in nature.

RESULTS

Among 3,940 evaluable patients, 26% were elderly (older than 65 years of age). More than half of the population had pN0 tumor stage. Ninety-four percent received chemotherapy: 78% as adjuvant treatment and 14% as neoadjuvant treatment, 2% both. Anthracyclines were administered in 87% and taxanes in 66%. Trastuzumab was stopped prematurely in 9% (because of cardiotoxicity in 3.5%). Recurrence-free survival was 90.0% (95% confidence interval [CI], 88.9%-91.1%) and 82.8% (95% CI, 81.2%-84.4%) after 3 and 5 years, respectively. The corresponding figures for overall survival were 96.8% (95% CI, 96.1%-97.6%) and 90.0% (95% CI, 88.6%-91.4%). Pathological primary tumor size, lymph node involvement, and hormone receptor status had the greatest independent effect on recurrence risk. Cardiac function toxicity of National Cancer Institute common toxicity criteria grade ≥2 and ≥3 was observed in 2.5% and less than 1% of patients, respectively.

CONCLUSION

The maturing follow-up data seem to confirm the beneficial results of trastuzumab treatment for early breast cancer from the randomized studies. Moreover, these findings support use of trastuzumab-based therapy in patients groups less commonly included in the phase III trials (e.g., elderly patients and those with stage I disease). The Oncologist 2017;22:131-138Implications for Practice: On the basis of the results of large pivotal phase III studies, the inclusion of trastuzumab in adjuvant treatment regimens for human epidermal growth factor receptor 2-positive breast cancer is standard of care. However, in these trials, elderly patients, those with comorbidities, and/or those with contraindications or refusal of cytotoxic chemotherapy are typically underrepresented. This study provides data on observed treatment options, outcomes, and risks in a wider, unselected patient population (including more than 1,000 patients with stage I disease), treated routinely in several institutions of varying size and location across Germany.

Trastuzumab in the Treatment of Breast Cancer

Breast cancer (BC) is the most common cancer in women worldwide, and has an undeniable negative impact on public health. The advent of molecular biology and immunotherapy has made targeted therapeutic interventions possible, providing treatments tailored to the individual characteristics of the patient and the disease. The over-expression of human epidermal growth factor receptor (HER) 2 is implicated in the pathophysiology of BC and represents a clinically relevant biomarker for its treatment. Trastuzumab, a recombinant antibody targeting HER2, was the first biological drug approved for the treatment of HER2-positive BC. Although there are currently other anti-HER2 agents available (e.g. pertuzumab and lapatinib), trastuzumab remains the gold standard for treatment of this disease subtype. Nonetheless, concerns have been raised regarding potential cardiotoxicity and treatment resistance. Moreover, several other therapeutic issues remain unclear and have been addressed in an inconsistent way. The current literature lacks a comprehensive review of trastuzumab providing useful information for clinical practice, including pharmacokinetic and pharmacodynamic aspects, its clinical use, existing controversies and future advances. This detailed review of trastuzumab in the pharmacotherapy of BC attempts to fill this gap.

Twenty years of anti-HER2 therapy-associated cardiotoxicity

Over the past 20 years, the prognosis of HER2-positive breast cancer has been transformed by the development of anti-HER2 targeted therapies. In early clinical trials of trastuzumab (ie, the first anti-HER2 agent to be developed) cardiotoxicity became a major concern. In the first published phase 3 trial of trastuzumab, 27% of patients receiving anthracyclines and trastuzumab experienced cardiac events and 16% suffered from severe congestive heart failure. In subsequent trials conducted in advanced and early settings, the incidence of cardiac events was reduced through changes in chemotherapy regimens, more strict patient selection and close cardiac assessment. However, cardiotoxicity remains a significant problem in clinical practice that is likely to increase as new agents are approved and exposure times increase through improved patients' survival. Though numerous trials have led to improved understanding of many aspects of anti-HER2 therapy-related cardiotoxicity, its underlying physiopathology mechanisms are not well understood. The purpose of this article is to provide an in-depth review on anti-HER2 therapy-related cardiotoxicity, including data on both trastuzumab and the recently developed anti-HER2 targeted agents.

In a cohort of breast cancer screened patients the proportion of HER2 positive cases is lower than that earlier reported and pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases

Human epithelial growth factor receptor 2 (HER2) overexpression and/or amplification is of predictive and prognostic value in infiltrating breast carcinoma (IBC). We evaluated the proportion of HER2-positive cases (score 3 overexpression/score 2 plus fluorescence in situ hybridization (FISH) amplification) in a consecutive series of 2163 patients. According to immunohistochemical analysis of HER2 expression, using Herceptest and FDA criteria, 839 cases had score 0, 476 score 1+, 699 score 2+, and 149 score 3+. Of the 699 scoring 2+ cases, 160 (22.88 %) showed Her2 gene amplification by FISH analysis, making a total of 309 (14.28 %) HER2-positive cases. Grade 1 ductal and special type IBC were never HER2 positive, while only three infiltrating lobular carcinomas but a relevant percentage of small IBC were HER2 positive. Of HER2-positive cases, 52.1 % was pT1 and of these, 38.5 % was pT1b or smaller. Logistic regression analysis revealed that estrogen receptor (ER), progesterone receptor (PgR), grade, and pT were significantly associated with HER2 positivity and that HER2 3+ cases were more frequently of higher grade and pT than HER2 2+/Her2 amplified cases. In addition, HER2 3+ cases were more frequently in ER and PgR negative than HER2 2+/Her2 amplified cases. We conclude that the proportion of HER2 positive cases is lower than that reported in older literature and that pathological characteristics differ between HER2 3+ and HER2 2+/Her2 amplified cases.

The clinical value of HER-2 overexpression and PIK3CA mutations in the older breast cancer population: a FOCUS study analysis

Studies to confirm the effect of acknowledged prognostic markers in older breast cancer patients are scarce. The aim of this study was to evaluate the prognostic value of HER-2 overexpression and PIK3CA mutations in older breast cancer patients. Female breast cancer patients aged 65 years or older, diagnosed between 1997 and 2004 in a geographical region in The Netherlands, with an invasive, non-metastatic tumour and tumour material available, were included in the study. The primary endpoint was relapse-free period and secondary endpoint was relative survival. Determinants were immunochemical HER-2 scores (0/1+, 2+ or 3+) and PIK3CA as a binary measure. Overall, 1698 patients were included, and 103 had a HER-2 score of 3+. HER-2 overexpression was associated with a higher recurrence risk (5 years recurrence risk 34 % vs. 12 %, adjusted p = 0.005), and a worse relative survival (10 years relative survival 48 % vs. 84 % for HER-2 negative; p = 0.004). PIK3CA mutations had no significant prognostic effect. We showed, in older breast cancer patients, that HER-2 overexpression was significantly associated with a worse outcome, but PIK3CA mutations had no prognostic effect. These results imply that older patients with HER-2 overexpressing breast cancer might benefit from additional targeted anti-HER-2 therapy.

Trastuzumab in the treatment of elderly patients with early breast cancer: Results from an observational study in Germany

BACKGROUND

In elderly patients with HER2-positive breast cancer, few data on efficacy and toxicity of adjuvant trastuzumab treatment exists since older patients were in general excluded from large randomized studies. This prospective observational study aimed to confirm the beneficial findings from pivotal trials in age cohorts ≥65 years.

MATERIALS AND METHODS

There were no restrictions for recruitment with respect to age or concomitant/sequential adjuvant medication. Long-term relapse/survival status of the patients was assessed once a year.

RESULTS

Among the 3940 evaluable patients enrolled between 2006 and 2012 at 339 institutions, 507 were aged between 65 and 69 years, with another 507 patients ≥70 years. Elderly patients suffered from significantly more advanced primary tumors. Preceding or concomitant chemotherapy showed decreasing aggressiveness with patient's age. Trastuzumab treatment was stopped prematurely in only 11% of the elderly, but more often than in younger patients (p=0.0008). With 453 events hitherto reported, elderly patients did not exhibit an inferior relapse-free survival when adjusted for other relevant prognostic factors (hazard ratio: 1.01 per year; p=0.24). Three-year overall survival was significantly lower in the population older than 64 years than in younger patients (94.2% vs. 96.8%, p=0.0011).

CONCLUSIONS

To our knowledge, our population of elderly patients treated with adjuvant trastuzumab is the largest analyzed so far. The beneficial long-term results were comparable to those in the younger cohorts. Although the risk of cardiotoxicity increased significantly with age, it also remained manageable in older patients. Thus, chronological age alone should not preclude HER2 antibody treatment.