HER2阳性胃癌的治疗进展

【摘要】〓胃癌居全球恶性肿瘤发病率排行榜的第四位,手术、放疗和化疗的综合治疗为主要治疗手段,但疗效有限。随着胃癌分子生物学的发展,胃癌的靶基因被检测,针对靶基因的靶向药物亦被逐渐用于胃癌的临床治疗,尤其是HER2靶基因的发现及相关靶向药物的治疗给胃癌患者带来了新的希望。本文就HER2阳性胃癌的治疗进展作一综述。     

Co-overexpression of HER2/HER3 is a predictor of impaired survival in breast cancer patients

BackgroundRecently, HER3-expression was postulated as independent risk factor for metastatic spread. Therefore, we investigated the role of HER3 expression as prognostic marker in metastatic breast cancer patients.MethodsPatients of different breast cancer subtypes diagnosed with metastatic disease (visceral and/or brain metastases) were identified from a breast cancer database. Tissue samples of the respective primary tumors were retrieved, and immunohistochemical staining for estrogen-receptor, progesterone-receptor, HER2, and HER3 was performed. In HER2 equivocal and selected HER3 positive cases, subsequent fluorescent in situ hybridization (FISH) analysis was performed.ResultsTissue specimens of 110 patients were available for this analysis. 21% had strong, complete, membranous HER3 staining of at least 10% of all tumor cells; HER3 protein expression was not associated with HER3 gene amplification. HER2/HER3 co-overexpression was observed in 12/110 (11%) specimens and HER3-overexpression showed a statistically significant association with HER2-overexpression (p = 0.02). No correlation was observed for HER3-overexpression and overall survival (OS), time to diagnosis of brain metastases, and incidence of brain metastases. Still, in patients with HER3 overexpression, a higher rate of ‘brain only’ metastatic behavior was observed (p = 0.042). In the HER2-positive subgroup, HER3-overexpression was significantly associated with shorter OS from diagnosis of metastatic disease (median 17 vs. 35 months; p = 0.04; log rank test).ConclusionsHER2/HER3 co-overexpression is significantly associated with impaired OS from diagnosis of metastatic disease in patients with HER2-positive metastatic breast cancer. Co-inhibition of HER2 and HER3 or the inhibition of HER2/HER3 hetero-dimerization may improve clinical outcome in this subgroup.     

Treatment of HER2-positive breast cancer

The human epidermal growth factor receptor 2 gene (HER2) is overexpressed and/or amplified in ∼15% of breast cancer patients and was identified a quarter century ago as a marker of poor prognosis. By 1998, antibody therapy targeting the HER2 pathway was shown to demonstrably improve progression-free and overall survival in metastatic disease, and in 2005 evidence of improvement in disease-free and overall survival from the first generation of trastuzumab adjuvant trials became available. However, not all patients with HER2 overexpression benefit from trastuzumab. Second-generation studies in metastatic disease led to the approval of several new HER2-targeted therapies using small molecule tyrosine kinase inhibitors such as lapatinib, new HER2/HER3 antibodies such as pertuzumab, and the new antibody chemotherapy conjugate ado-trastuzumab emtansine. These successes supported the launch of second-generation adjuvant trials testing single and dual HER2-targeted agents, administered concomitantly or sequentially with chemotherapy that will soon complete accrual. HER2-positive breast cancer in the setting of HER2-targeted therapy is no longer associated with poor prognosis, and recent guidance by the US Food and Drug Administration suggests that pathologic response to HER2-targeted therapy given preoperatively may allow an earlier assessment of their clinical benefit in the adjuvant setting. An adjuvant trial of trastuzumab in patient whose tumors express normal levels of HER2 and trials of single/dual HER2-targeting without chemotherapy are also ongoing. In this article, we review the current data on the therapeutic management of HER2-positive breast cancer.     

Do all patients with HER2 positive breast cancer require one year of adjuvant trastuzumab? A systematic review and meta-analysis

One year of adjuvant trastuzumab is considered the standard treatment for patients with HER2 positive breast cancer. However, a shorter duration of trastuzumab may be associated with reduced costs and side effects. Results from randomized trials with diverse non-inferiority margins comparing one year to a shorter duration of adjuvant trastuzumab are not consistent and have not been systematically reviewed using a non-inferiority meta-analysis approach.We conducted a systematic review and meta-analysis of randomized trials to assess whether a shorter duration of adjuvant trastuzumab was non-inferior to one year of treatment or not. The non-inferiority margin for the meta-analysis was pre-defined as the median of the margins of all the trials included. Data of 11,376 patients from 5 trials were analyzed. Non-inferiority margins in included studies varied from 1.15 to 1.53 with median of 1.29 for HR of DFS. A shorter duration of trastuzumab was non-inferior to one year of therapy for DFS (HR 1.13, 95%CI 1.03–1.24) but inconclusive for OS (HR 1.14, 95%CI 1.00–1.30). In a subgroup analysis for DFS outcome, shorter therapy was non-inferior in patients with ER positive disease (HR 1.10, 95%CI 0.95–1.28) and those with sequential therapy (HR 0.97, 95%CI 0.75–1.27) and when the duration of treatment was 6 months (HR 1.09, 95%CI 0.98–1.22). Although a shorter duration of adjuvant trastuzumab was non-inferior to one year of therapy for DFS in patients with HER2 positive breast cancer based on our HR margin of 1.29, any benefit of a shorter duration comes at a loss of efficacy with an increase in absolute risk up to 3.9% for 5 year DFS. Whether the potential increased risk is clinically acceptable for the benefits of a shorter duration remains debatable.     

Adjuvant trastuzumab without chemotherapy for treating early HER2-positive breast cancer in older patients: A propensity score-adjusted analysis of a prospective cohort study

PurposeTo gauge the effects of treatment practices on prognosis for older patients with HER2-positive early breast cancer, particularly to determine whether adjuvant trastuzumab alone can offer benefit over no adjuvant therapy. This is a prospective cohort study which accompanies the RESPECT that is a randomized-controlled trial (RCT).MethodsPatients who declined the RCT were treated based on the physician's discretion. We studied the 1) trastuzumab-plus-chemotherapy group, 2) trastuzumab-monotherapy group, and 3) non-trastuzumab group (no therapy or anticancer therapy without trastuzumab). The primary endpoint was disease-free survival (DFS), which was compared using the propensity-score method. Relapse-free survival (RFS) and health-related quality of life (HRQoL) were assessed.ResultsWe enrolled 123 patients aged over 70 years (median: 74.5). Treatment categories were: trastuzumab-plus-chemotherapy group (n = 36, 30%), trastuzumab-monotherapy group (n = 52, 43%), and non-trastuzumab group (n = 32, 27%). The 3-year DFS was 96.7% in trastuzumab-plus-chemotherapy group, 89.2% in trastuzumab-monotherapy group, and 82.5% in non-trastuzumab group. DFS in non-trastuzumab group was lower than in trastuzumab-plus-chemotherapy and trastuzumab-monotherapy groups (propensity-adjusted hazard ratio; HR: 3.29; 95% CI: 1.15–9.39; P = 0.026). The RFS in non-trastuzumab group was lower than in trastuzumab-plus-chemotherapy and trastuzumab-monotherapy groups (propensity-adjusted HR = 7.80; 95% CI: 2.32–26.2, P < 0.0001). There were no significant intergroup differences in the proportions of patients showing HRQoL deterioration at 36 months (P = 0.717).ConclusionTrastuzumab-treated patients had better prognoses than patients not treated with trastuzumab without deterioration of HRQoL. Trastuzumab monotherapy could be considered for older patients who reject chemotherapy.     

Locoregional recurrence in patients with HER2 positive breast cancer

Literature shows that HER2/neu positive breast cancer cells are more sensitive to radiation-induced apoptosis by targeting the epidermal growth factor receptor family tyrosine kinase. We selected 466 patients with pT1-2 HER2/neu positive tumors who received adjuvant trastuzumab for primary invasive breast cancer. Patients were divided into three groups [Quadrantectomy followed by conventional radiotherapy vs Quadrantectomy followed by Intra-operative radiotherapy with electrons vs Mastectomy without radiotherapy]. After a median follow-up of 52 months, the 5-year cumulative incidence of locoregional recurrence (LRR) was 1.9%, 11.5% and 5.0% respectively (p < 0.01). At the multivariate analysis, extensive perivascular invasion, Luminal B HER2/Progesterone Receptor (PgR) negative status and Quadrantectomy followed by Intra-operative radiotherapy with electrons have significantly increased the risk of LRR. Our results suggest that HER2/neu positive breast cancer might have better outcomes when treated simultaneously with external radiotherapy and trastuzumab. Moreover, we underline the importance of PgR and further new stratification of risk among luminal subtypes.     

HER2 Expression in Gastrointestinal Carcinoid Tumors: High in Intestinal but not in Gastric Tumors

We investigated HER2 expression immunohistochemically in 12 patients with a gastrointestinal (GI) carcinoid tumor. The tumors were located in the stomach in three patients, the duodenum in four, the vermiform appendix in one, and the rectum in four. HER2 was highly expressed in the nine intestinal, but not in the three gastric carcinoid tumors. These findings suggest that HER2 might be highly expressed in intestinal, but not in gastric, carcinoid tumors.     

Clinical outcome in women with HER2-positive de novo or recurring stage IV breast cancer receiving trastuzumab-based therapy

BackgroundFive to 10% of women with newly diagnosed breast cancer have synchronous metastases (de novo stage IV). A further 20% will develop metastases during follow-up (recurring stage IV). We compared the clinical outcomes of women with HER2-positive metastatic breast cancer (MBC) receiving first-line trastuzumab-based therapy according to type of metastatic presentation.Patients and methodsRetrospective analysis of 331 MBC patients receiving first-line trastuzumab-based treatment. Response rates (RR) were compared by the chi-square test. Time-to progression (TTP) and overall survival (OS) curves were compared by the log-rank test. Cox-proportional hazards models were used to study predictors of PFS and OS, including the type of metastatic presentation.ResultsSeventy-seven patients (23%) had de novo stage IV disease. Forty-six of these patients underwent surgery of the primary (“de novo/surgery”). Response rates to first-line trastuzumab-based therapy and median progression-free survival did not differ in patients with “recurring”, “de novo/surgery” and “de novo” without surgery (“de novo/no surgery) stage IV breast cancer. However, women with “de novo/surgery” stage IV breast cancer had the longest median OS (60 months), and those with “de novo/no surgery” stage IV breast cancer the shortest (26 months). For women with recurring metastatic breast cancer median OS was 40 months (overall log-rank test, p < 0.01). Multivariate analysis confirmed these findings.ConclusionOur analysis shows that response rates and PFS to first-line trastuzumab-based therapy do not differ significantly between de novo and recurring stage IV, HER2 positive breast cancer. The observed difference in OS favoring women with de novo stage IV disease submitted to surgery of the primary tumor could be the result of a selection bias.     

Circulating tumor cells and response to neoadjuvant paclitaxel and HER2-targeted therapy: A sub-study from the NeoALTTO phase III trial

BackgroundThe role of circulating tumor cells (CTCs) in HER2-positive breast cancer patients receiving neoadjuvant therapy is unclear.Patients & methodsWe describe the CTC detection rate, HER2 phenotyping and pathological complete response (pCR) in patients enrolled in the NeoALTTO phase III trial. Participation in the CTC sub-study was optional. CTC evaluation was performed centrally using CellSearch^® at baseline, week 2 and week 18 (prior to surgery) of neoadjuvant therapy.ResultsSamples for CTC analysis were available for 51/455 patients randomized. At baseline, week 2 and week 18, we detected ≥1 CTC/22.5 ml in 5/46 (11%), 4/41 (10%), and 5/31 (16%) patients and ≥1 HER2-positive CTC/22.5 ml in 2/46 (4%), 2/41 (5%), and 3/31 (10%) patients with evaluable samples, respectively. 11/51 patients (21%) had ≥1 CTC/22.5 ml in at least one time point. pCR was observed in 3/11 (27.3%) versus 17/40 (42.5%) patients with detectable and no detectable CTCs, respectively (p = 0.36). No pCR was observed in the three patients with detectable HER2-positive CTCs prior to surgery.ConclusionNumerically lower pCR rates were observed in patients with detectable CTCs, yet the study remains underpowered. A meta-analysis of CTC studies in this setting is warranted.     

EGFR, HER2, and HER3 Expression in Laryngeal Primary Tumors and Corresponding Metastases

Background There are several substances available to target members of the epidermal growth factor receptor (EGFR) family, both for imaging in nuclear medicine and for various forms of therapy. The level and stability of expression in both primary tumors and corresponding metastases is crucial in the assessment of a receptor as a target in systemic tumor therapy. To date, the expression of EGFR family members has only been determined in primary laryngeal carcinomas, and we have not found published data regarding the receptor status in corresponding metastatic lesions. Methods Expression of EGFR, HER2, and HER3 was investigated immunohistochemically in both lymph node metastases and corresponding primary laryngeal squamous carcinomas (n = 40). Results EGFR overexpression (2+ or 3+) was found in 87.5% (35/40) of the laryngeal primary tumors and 82.5% (33/40) of the corresponding lymph node metastases. There was a good agreement between the primary tumors and the paired metastases regarding EGFR expression. HER2 overexpression was found in only four cases (10.5%) of the studied primary tumors and in all cases the HER2 expression was retained in the paired metastases. Another two metastases gained HER2 status when compared to the corresponding primary tumors. Strong HER3 staining was found in 26.7% of both the primary tumors and the corresponding metastases. Conclusions The high frequency and stability in EGFR expression is encouraging for efforts to use EGFR targeting agents (e.g. Iressa, Tarceva, Erbitux or radiolabeled antibodies) for therapy of laryngeal carcinoma. For a few laryngeal carcinoma patients with HER2 overexpression, anti-HER2 agents could possibly be used.     

Investigating the Combination of Trastuzumab and HER2/neu Peptide Vaccines for the Treatment of Breast Cancer

Background Trastuzumab, an anti-HER2/neu monoclonal antibody, is thought to promote HER2/neu receptor internalization and/or turnover. This study was designed to investigate the kinetics of trastuzumab treatment on tumor cells with varying levels of HER2/neu expression and to determine the effect of trastuzumab on HER2/neu-specific cytotoxic T lymphocyte–mediated lysis. Methods Three cell lines with varying levels of HER2/neu expression were incubated with varying doses of trastuzumab at multiple time points. Trastuzumab binding and HER2/neu expression were determined. Peripheral blood mononuclear cells from three HLA-A2⁺ healthy donors and four E75 peptide–vaccinated patients were stimulated with HER2/neu-derived peptides and tested in standard chromium release cytotoxicity assays with HER2/neu⁺ tumor cells pretreated with trastuzumab. Results Treatment of tumor cells with 10 μg/mL of trastuzumab in an overnight incubation resulted in saturation of cell-surface HER2/neu receptors. At higher doses, trastuzumab staining and HER2/neu expression decreased in a time-dependent manner. Pretreatment of tumor cells with trastuzumab resulted in increases in specific cytotoxicity by peptide-stimulated cytotoxic T lymphocytes from HLA-A2⁺ donors over untreated cells by an average of 5.6% and 15.3% (P = .0002) for doses of 10 and 50 μg/mL, respectively. In similar experiments involving peripheral blood mononuclear cells obtained from immunized patients, the average specific cytotoxicity for untreated cells was 34.2% ± 1.3% vs. 40.6% ± 2.5% (P = .035) and 40.7% ± 1.6% (P = .0005) for those treated with 10 and 50 μg/mL, respectively. Conclusions Our data suggest that pretreatment of breast cancer cells with trastuzumab induces turnover of the HER2/neu protein and enhanced killing by HER2/neu peptide–stimulated CTLs. This increased lysis occurs regardless of the degree of HER2/neu expression and seems more pronounced in vaccinated patients. These findings support further investigation into the use of combination immunotherapy with trastuzumab and HER2/neu peptide–based vaccines. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or reflecting the views of the Department of the Army or the Department of Defense.     

Extremely Well Differentiated Adenocarcinoma of the Stomach Diagnosed Preoperatively as Esophageal Achalasia: Report of a Case

Extremely well differentiated primary gastric adenocarcinoma, which accounts for less than 0.2% of all gastric cancers, is associated with a better prognosis than other types of differentiated adenocarcinoma. Among 2070 gastric carcinomas, diagnosed between 1983 and 2002 at Fukuoka University Hospital and Hamanomachi Hospital, there were three cases of primary extremely well differentiated adenocarcinoma. We report the clinicopathological details of one case of primary gastric extremely well differentiated adenocarcinoma. A 57-year-old man was reffered to our hospital for investigation and treatment of a gastric tumor. Physical and laboratory examinations revealed no abnormalities except for diabetes mellitus. Radiological, endoscopic, and imaging examinations showed an esophageal achalasia-like stenotic lesion. The surface mucosa consisted of almost normal epithelium without any signs of malignancy. Macroscopically, the surgical specimen contained a submucosal tumor, and histological examination revealed extremely well differentiated adenocarcinoma. Although this type of carcinoma is very rare, it should be considered in the differential diagnosis of esophageal and gastric mucosal lesions.     

Real-world data of HER2-low metastatic breast cancer: A population based cohort study

BackgroundWith the introduction of investigational human epidermal growth factor receptor 2 (HER2) targeting treatments, thorough understanding of breast cancer with different HER2 expression levels is critical. The aim of this study was to compare clinicopathologic characteristics and survival of patients with metastatic breast cancer according to the level of HER2 expression.MethodsWomen with distant metastatic breast cancer during 2008–2016 were selected from PALGA, the Dutch Pathology Registry, and linked to the PHARMO Database Network. Breast cancer samples were categorised as HER2 immunohistochemistry score 0 (IHC0), HER2-low or HER2+.ResultsAmong women with hormone receptor (HR) positive metastatic breast cancer (n = 989), 373 (38%) cancers were HER2 IHC0, 472 (48%) were HER2-low and 144 (15%) were HER2+. Among HR negative patients (n = 272), the proportion of HER2 IHC0, HER2-low and HER2+ was 110 (40%), 104 (38%) and 58 (21%) respectively.Within the HR + cohort, patients with HER2 IHC0 or HER2-low cancer were significantly older compared to HER2+ patients. This age difference was not seen in the HR-cohort. The localisation of distant metastases differed significantly between HER2 IHC0 or HER2-low versus HER2+ cases. Survival rates did not differ markedly by subtypes.ConclusionSubstantial proportion of patients had a HER2-low breast cancer. No clear differences in survival were found when comparing HER2 and HR status. Getting more granular insights in the level of HER2 expression and addressing HER2-low as a separate category could help to assess the impact of emerging treatment strategies. Therefore, more detailed information on HER2 expression should be routinely reported.     

Pathologic complete response after neoadjuvant chemotherapy in HER2-overexpressing breast cancer according to hormonal receptor status

ObjectiveFor patients with HER2-positive breast cancer, the prognostic impact of pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) is unclear when stratified by hormonal receptor (HR) status; however, the impact of pCR on survival when stratified by hormonal receptor (HR) status is uncertain.Patients and methodsThis multicenter retrospective study investigated the predictors of pCR and its prognostic value in Japanese patients 366 HER2-positive breast cancer who received NAC. pCR was defined as no invasive residual tumor in the breast or axilla.ResultsMedian follow-up was 55 months. Multivariate analysis revealed that HR status (OR, 0.37; p < 0.001) was one of the independent predictors of pCR. Five-year recurrence-free survival was higher in HR-negative patients with pCR (93%) than in those without pCR (68%), and pCR was independently prognostic (hazard ratio, 0.32; p = 0.005). However, 5-year recurrence-free survival was not different between HR-positive patients with pCR (94%) and those without pCR (84%), and pCR was not significantly prognostic (hazard ratio, 0.53; p = 0.39). In addition, 5-year overall survivals were high and similar (97% in pCR, 94% in non-pCR). Among 204 patients treated with neoadjuvant trastuzumab, pCR was not significantly prognostic in the HR-positive group (hazard ratio, 0.63; p = 0.56).ConclusionOur study suggested that the HER2-positive HR-positive patients had a good prognosis despite the lower achievement rate of pCR, whose prognostic impact was smaller than that in the HER2-positive HR-negative patients. The treatment strategy for HER2-positive breast cancer can be stratified by HR status.     

First report of eribulin in combination with pertuzumab and trastuzumab for advanced HER2-positive breast cancer

BackgroundThe efficacy and safety of continuing multiple anti-HER2 therapies in advanced breast cancer (ABC) patients remains unclear. This study investigated eribulin in combination with pertuzumab and trastuzumab for both taxane- and trastuzumab-pretreated HER2-positive ABC patients.MethodsIn a single-institute, single-arm, open-label, phase II trial, HER2-positive ABC patients who had previously received taxanes and trastuzumab were treated with eribulin in combination with pertuzumab and trastuzumab. The pharmacokinetics of eribulin in this combination were assessed in 6 patients. Tumor assessments were conducted every 6 weeks for the first 6 cycles and every 12 weeks thereafter. The primary endpoint was objective response rate (ORR).ResultsA total of 30 patients (median age, 58 years; range, 31–76) were enrolled, with a median number of previous chemotherapy regimens of 3.5 (range: 1–9) in the metastatic setting. Pharmacokinetic parameters of eribulin in this combination were similar to previous reports of eribulin monotherapy. ORR was 34.8% (95% CI: 16.4–57.3, n = 23), and median progression-free survival was 42.6 weeks (95% CI: 20.3–51.9, n = 30). Clinical benefit rate was 60.9% (95% CI: 16.4–57.3). The most common grade 3/4 adverse event was neutropenia in 20 patients (66.7%). A dose reduction of eribulin was required in 27 patients due to adverse events, particularly grade 3 neutropenia.ConclusionsEribulin in combination with pertuzumab and trastuzumab was well tolerated in heavily pretreated patients. Eribulin may be a viable treatment option when used in combination with pertuzumab and trastuzumab for HER2-positive ABC patients (UMIN Clinical Trial Registry identification number, UMIN000012375).     

Clinical Significance of the Epidermal Growth Factor Receptor and HER2 Receptor in Resectable Gastric Cancer

Background: Epidermal growth factor receptor (EGFR or HER1) and its homolog c-erbB-2 (HER2) are membrane receptors. Both EGFR and HER2 genes are overexpressed in a variety of solid human cancers and are related to poor prognosis of the patients. The objective of this work was to evaluate the EGFR and HER2 contents in resectable gastric cancer, their possible relationship with clinicopathologic parameters of tumors, and their prognostic significance.Methods: This was a prospective analysis of 63 patients with resectable gastric carcinomas, with a mean follow-up period of 40.7 months. Membranous EGFR levels were examined by radioligand binding assays, and cytosolic HER2 levels were examined by means of an immunoenzymatic assay.Results: There was a wide variability of EGFR (1–1,239 fmol/mg of protein) and HER2 (7–20,863 NHU/mg of protein) levels in tumors. There was no significant correlation between these levels and patient or tumor characteristics. However, high levels of EGFR and HER2 were significantly associated with a shorter overall survival period (P = .03 and P = .02, respectively).Conclusions: There is a wide variability in membranous EGFR levels and in cytosolic HER2 levels in gastric cancer, which seems to be related to the biological heterogeneity of these tumors. In addition, high tumor EGFR and HER2 levels were associated with an unfavorable outcome in patients with resectable gastric cancer.     

Targeting ADCC: A different approach to HER2 breast cancer in the immunotherapy era

The clinical outcome of patients with human epidermal growth factor receptor 2 (HER2) amplified breast carcinoma (BC) has improved with the development of anti-HER2 targeted therapies. However, patients can experience disease recurrence after curative intent and disease progression in the metastatic setting. In the current era of evolving immunotherapy agents, the understanding of the immune response against HER2 tumor cells developed by anti-HER2 antibodies (Abs) is rapidly evolving. Trastuzumab therapy promotes Natural Killer (NK) cell activation in patients with BC overexpressing HER2, indicating that the efficacy of short-term trastuzumab monotherapy, albeit direct inhibition of HER, could also be related with antibody-dependent cell-mediated cytotoxicity (ADCC). Currently, dual HER2 blockade using trastuzumab and pertuzumab is the standard of care in early and advanced disease as this combination could confer an additive effect in ADCC. In patients with disease relapse or progression, ADCC may be hampered by several factors such as FcγRIIIa polymorphism and an immunosuppressive environment, among others. Hence, new drug development strategies are being investigated aiming to boost the ADCC response triggered by anti-HER2 therapy. In this review, we summarize these strategies and the rationale, through mAbs engineering and combinatorial strategies, focusing on clinical results and ongoing trials.