Digital droplet PCR (ddPCR) for the detection and quantification of HPV 16, 18, 33 and 45 - a short report

Purpose

Human papilloma virus (HPV) infection is associated with several anogenital malignancies. Here, we set out to evaluate digital droplet PCR (ddPCR) as a tool for HPV 16, 18, 33 and 45 viral load quantification and, in addition, to compare the efficacy of the ddPCR assay for HPV 16 detection with that of quantitative real-time PCR (qPCR).

Methods

Clinical samples, positive for HPV genotypes 16, 18, 33 and 45 were analyzed for viral load using ddPCR. Sample DNA was cleaved before droplet generation and PCR. Droplets positive for VIC and FAM fluorescence were read in a QX200 Droplet reader? (BIO-RAD) after which the viral load was calculated using Quantasoft software.

Results

We found that DNAs extracted from formalin fixed paraffin embedded (FFPE) tissue samples yielded lower amplification signals compared to those obtained from liquid based cytology (LBC) samples, but they were clearly distinguishable from negative background signals. The viral limit of detection was 1.6 copies of HPV 16, 2.8 copies of HPV 18, 4.6 copies of HPV 33 and 1.6 copies of HPV 45. The mean inter-assay coefficients of variability (CV) for the assays ranged from 3.4 to 7.0%, and the mean intra-assay CV from 2.6 to 8.2%. The viral load in the different cohorts of tumor samples ranged from 154 to 340,200 copies for HPV 16, 244 to 31,300 copies for HPV 18 and 738 to 69,100 copies for HPV 33. One sample positive for HPV 45 contained 1331 viral copies. When comparing qPCR data with ddPCR copy number data, the qPCR values were found to be 1 to 31 times higher.

Conclusions

Separation of fragments in nanodroplets may facilitate the amplification of fragmented human and viral DNA. The method of digital droplet PCR may, thus, provide a new and promising tool for evaluating the HPV viral load in clinical samples.

     

Prognostic significance of performing universal HER2 testing in cases of advanced gastric cancer

Background

Trastuzumab significantly improves overall survival (OS) when added to cisplatin and fluoropyrimidine as a treatment for HER2-positive advanced gastric cancers (AGC). The aim of this study was to evaluate the impact of the gradual implementation of HER2 testing on patient prognosis in a national registry of AGC.

Methods

This Spanish National Cancer Registry includes cases who were consecutively recruited at 28 centers from January 2008 to January 2016. The effect of missing HER2 status was assessed using stratified Cox proportional hazards (PH) regression.

Results

The rate of HER2 testing increased steadily over time, from 58.3 % in 2008 to 92.9 % in 2016. HER2 was positive in 194 tumors (21.3 %). In the stratified Cox PH regression, each 1 % increase in patients who were not tested for HER2 at the institutions was associated with an approximately 0.3 % increase in the risk of death: hazard ratio, 1.0035 (CI 95 %, 1.001–1.005), P = 0.0019. Median OS was significantly lower at institutions with the highest proportions of patients who were not tested for HER2.

Conclusion

Patients treated at centers that took longer to implement HER2 testing exhibited worse clinical outcomes. The speed of implementation behaves as a quality-of-care indicator. Reviewed guidelines on HER2 testing should be used to achieve this goal in a timely manner.

     

Mass-spectrometry-based quantitation of Her2 in gastroesophageal tumor tissue: comparison to IHC and FISH

Background

Trastuzumab has shown a survival benefit in cases of Her2-positive gastroesophageal cancer (GEC). Immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) currently determine eligibility for trastuzumab-based therapy. However, these low-throughput assays often produce discordant or equivocal results.

Methods

We developed a targeted proteomic assay based on selected reaction monitoring mass spectrometry (SRM-MS) and quantified levels (amol/μg) of Her2-SRM protein in cell lines (n = 27) and GEC tissues (n = 139). We compared Her2-SRM protein expression with IHC/FISH, seeking to determine optimal SRM protein expression cutoffs in order to identify HER2 gene amplification.

Results

After demonstrating assay development, precision, and stability, Her2-SRM protein measurement was observed to be highly concordant with the HER2/CEP17 ratio, particularly in a multivariate regression model adjusted for SRM expression of the covariates Met, Egfr, Her3, and HER2 heterogeneity, as well as their interactions (cell lines r ² = 0.9842; FFPE r ² = 0.7643). In GEC tissues, Her2-SRM protein was detected at any level in 71.2 % of cases. ROC curves demonstrated that Her2-SRM protein levels have a high specificity (100 %) at an upper-level cutoff of >750 amol/µg and sensitivity of 75 % at a lower-level cutoff of <450 amol/μg for identifying HER2 FISH-amplified tumors. An “equivocal zone” of 450–750 amol/µg of Her2-SRM protein was analogous to IHC2+ but represented fewer cases (9–16 % of cases versus 36–41 %).

Conclusions

Compared to IHC, targeted SRM-Her2 proteomics provided more objective and quantitative Her2 expression with excellent HER2/CEP17 FISH correlation and fewer equivocal cases. Along with its multiplex capability for other relevant oncoproteins, these results demonstrate a refined HER2 protein expression assay for clinical application.

     

Metabolic landscape of advanced gastric cancer according to HER2 and its prognostic implications

Background

In advanced gastric cancer (AGC), HER2 is a validated therapeutic target. However, the metabolic landscape of AGC based on HER2 status has not been reported. Furthermore, the prognostic value of HER2 in AGC is under debate. The purpose of this study was to determine the metabolic landscape and prognosis on the basis of HER2 status in AGC.

Methods

We analyzed 866 AGC patients treated with palliative chemotherapy and whose HER2 status was evaluated. HER2 positivity was defined as HER2 IHC 3+ or HER2/CEP17 ratio ≥2. Among them, 363 patients were evaluated with ¹⁸F FDG-PET before chemotherapy. We analyzed mSUV (maximal standardized uptake value) according to HER2 status and clinical outcomes.

Results

Among 866 patients, 225 (26.0 %) had HER2+ GC. The mSUV of HER2+ GC was significantly higher than that of HER2? GC (12.6 vs. 8.7, p < 0.001). Increased HER2 IHC positivity was correlated with increased mSUV (IHC?: 8.1, IHC 1+: 8.2, 2+: 11.4, 3+: 13.2, p < 0.001). Excluding HER2+ patients who received HER2-targeting agents, OS of patients was not different by HER2 status (12.5 vs. 11.9 months, p = 0.688). However, according to tumor metabolism, patients with higher mSUV showed worse OS regardless of HER2 positivity (mSUV < 12.8:14.8, ≥12.8:8.6 months, p < 0.001).

Conclusion

Tumor metabolism of AGC adversely influenced OS under treatment with cytotoxic chemotherapy. Tumor metabolism was higher in HER2+ AGC than HER2?. However, HER2 was not a prognostic factor in patients who received chemotherapy without HER2-targeting agents.

     

Multicenter phase II study of trastuzumab plus S-1 alone in elderly patients with HER2-positive advanced gastric cancer (JACCRO GC-06)

Background

S-1 plus cisplatin is a standard regimen for advanced gastric cancer (AGC) in Asia. The ToGA trial established a fluoropyrimidine plus cisplatin and trastuzumab as a standard treatment for human epidermal growth factor receptor 2 (HER2)-positive AGC. In the HERBIS-1 trial, trastuzumab combined with S-1 plus cisplatin showed promising antitumor activity in patients with HER2-positive AGC. However, cisplatin has several important drawbacks, including vomiting and renal toxicity. These disadvantages of cisplatin are prominent in elderly patients. Therefore, we conducted a prospective phase II study of trastuzumab plus S-1 without cisplatin in elderly patients with HER2-positive AGC.

Methods

Patients 65 years or older who had HER2-positive AGC received S-1 orally on days 1–28 of a 42-day cycle and trastuzumab intravenously on day 1 of a 21-day cycle.

Results

A total of 51 patients were enrolled. Two patients were ineligible. The full analysis set thus comprised 49 patients. The median age was 71 years (range 65–85). The confirmed response rate was 40.8% (95% CI 27.1–54.6%), and the null hypothesis was rejected. The median follow-up period was 10.6 months. Median overall survival was 15.8 months. Median progression-free survival was 5.1 months, and time to treatment failure was 4.0 months. Major grade 3 or 4 adverse events included neutropenia (12.0%), anemia (24.0%), diarrhea (10.0%), and anorexia (12.0%). There was one treatment-related death.

Conclusions

Trastuzumab in combination with S-1 alone demonstrated promising antitumor activity and manageable toxic effects as well as promising survival results in elderly patients with HER2-positive AGC.

Clinical trials registration

UMIN000007368.

     

Characteristics of Gastric Cancer in Lebanon: a Descriptive Study from a Single Institutional Experience

Background

The epidemiology of gastric cancer in the Middle East has never been described. Therefore, the characteristics of gastric cancer in the Lebanese population will be reported in this study.

Patients and Methods

A retrospective study that included all patients diagnosed with gastric cancer at Hotel Dieu de France University Hospital in Beirut, Lebanon between 2010 and 2016 was conducted. All eligible patients were reviewed for demographic and epidemiologic analysis.

Results

The study included 123 patients diagnosed with gastric cancer. The median age at diagnosis was 59 years (range 15–72 years), and the median ECOG performance status was 2 (range 1–4). Most patients were metastatic at diagnosis (52.8%), and diffuse pathology type was predominant (39%). HER2 was positive in 16.2% and correlated with the occurrence of hepatic metastasis (p = 0.048). The HER2 status did not differ significantly between the histological subtypes, the site of the tumor, the stage of the gastric cancer at diagnosis, and the recurrence of cancer (p > 0.05).

Conclusion

Gastric cancer in the Lebanese population is characterized by aggressive features such as advanced stage at diagnosis, high prevalence of diffuse type histology, and HER2 positivity.

     

Impact of HER2 expression on outcome in gastric cancer patients with liver metastasis

Purpose

We aim to investigate the correlation of HER2 expression with liver metastasis and the impact of HER2 status and trastuzumab therapy on the prognosis of gastric cancer with liver metastasis (GCLM) patients.

Methods

This prospective observational study was carriedout in Shanghai Zhongshan Hospital, Fudan University, from January 2012 to June 2015. HER2 status and baseline characteristics were collected from the patient record. GCLM patients were divided into three groups according to HER2 status and trastuzumab therapy.

Results

A total of 290 patients were included, and94 patients were diagnosed with liver metastasis. The HER2 positivity was 37.2 % (35/94) in GCLM patients and 21 % (61/290) in the overall GC patients. Among 94 GCLM patients, 28 HER2-positive patients received trastuzumab-based therapy (group A), 7 HER2-positive patients received chemotherapy alone (group B) and the other 59 patients were HER2 negative (group C). The median progression-free survival (PFS) for groups A, B and C was 7.83, 6.30 and 5.33 months, respectively (P = 0.007). The median overall survival (OS) for groups A, B and C was 12.00, 10.47 and 8.67 months, respectively (P = 0.056). Further Cox analysis showed that there was no significant difference in OS (P = 0.917) and PFS (P = 0.456) between group B and C.

Conclusions

HER2 positivity was higher in GCLM patients. HER2 status itself was not an independent prognostic factor in GCLM patients. Trastuzumab-based therapy could significantly improve survival in HER2-positive GCLM patients.

     

Occurrence and outcome of de novo metastatic breast cancer by subtype in a large,diverse population

Purpose

To examine the occurrence and outcomes of de novo metastatic (Stage IV) breast cancer, particularly with respect to tumor HER2 expression.

Methods

We studied all 6,268 de novo metastatic breast cancer cases diagnosed from 1 January 2005 to 31 December 2011 and reported to the California Cancer Registry. Molecular subtypes were classified according to HER2 and hormone receptor (HR, including estrogen and/or progesterone receptor) expression. Multivariable logistic regression was used to estimate odds ratios (ORs) and 95 % confidence intervals (CIs) of Stage IV versus Stage I–III breast cancer; Cox proportional hazards regression was used to assess relative hazard (RH) of mortality.

Results

Five percent of invasive breast cancer was metastatic at diagnosis. Compared to patients with earlier stage disease, patients with de novo metastatic disease were significantly more likely to have HER2+ tumors (HR+/HER2+: OR 1.29, 95 % CI 1.17–1.42; HR?/HER2+: OR 1.40, 95 %CI 1.25–1.57, vs. HR+/HER2?). Median survival improved over time, but varied substantially across race/ethnicity (Asians: 34 months; African Americans: 6 months), neighborhood socioeconomic status (SES) (highest: 34 months, lowest: 20 months), and molecular subtype (HR+/HER2+: 45 months; triple negative: 12 months). In a multivariable model, triple negative (RH 2.85, 95 % CI 2.50–3.24) and HR?/HER2+ (RH 1.60, 95 % CI 1.37–1.87) had worse, while HR+/HER2+ had similar, risk of all-cause death compared to HR+/HER2? breast cancer.

Conclusions

De novo metastatic breast cancer was more likely to be HER2+. Among metastatic tumors, those that were HER2+ had better survival than other subtypes.

     

Assessment of HER2 status in patients with gastroesophageal adenocarcinoma treated with epirubicin-based chemotherapy: heterogeneity-related issues and prognostic implications

Background

HER2 and topoisomerase 2 alpha (TOP2A) genomic status was previously reported to predict benefit from anthracyclines in breast cancer. We sought to define the prognostic impact and possible pitfalls related to these biomarkers in resectable gastroesophageal adenocarcinoma.

Methods

HER2 and TOP2A gene amplification by fluorescent in situ hybridization and HER2 protein expression by immunohistochemistry (IHC) were assessed on whole tissue sections from 101 patients receiving peri- or postoperative epirubicin-based chemotherapy. In a subgroup of patients, at least two matched tumor blocks, originating either from surgical procedures (n = 88) or diagnostic biopsies (n = 32), were available for HER2 analyses by IHC.

Results

Eighteen of 101 patients (17.8 %) were HER2 positive, whereas TOP2A was amplified in 4 of 84 patients (4.7 %). HER2 positivity was significantly associated with improved disease-free survival [HR = 0.47 (95 % CI 0.22–0.99), P = 0.046] and overall survival [HR = 0.33 (95 % CI 0.13–0.83), P < 0.018], independent of clinical-pathologic features. HER2 expression in matched tumor blocks from the same resection specimen was discordant in up to 11.8 % of pairs, while this rate increased up to 27.2 % when diagnostic biopsies and paired surgical samples were compared.

Conclusions

HER2 status is an independent prognostic biomarker in gastroesophageal adenocarcinomas receiving epirubicin-based chemotherapy. Compared to diagnostic biopsies, HER2 assessment in multiple resection specimens might lower the risk of sampling errors. These findings have several implications with respect to the optimal choice of the sample to be submitted to IHC testing of HER2.

     

Weekly paclitaxel plus carboplatin with or without trastuzumab as neoadjuvant chemotherapy for HER2-positive breast cancer: loss of HER2 amplification and its impact on response and prognosis

Purpose

Neoadjuvant chemotherapy (NCT) plus anti-HER2 agents are the standard of care for locally advanced HER2-positive breast cancer. The aim of this study was to evaluate the prevalence and prognostic impact of HER2 loss in patients with HER2-positive disease treated with neoadjuvant therapy with or without trastuzumab.

Methods

549 consecutive HER2-positive patients were included in this study. 379 patients were treated with paclitaxel, carboplatin, and trastuzumab (PCH cohort) and 170 were treated with paclitaxel and carboplatin only (PC cohort). Conversion of biomarkers before and after NCT was evaluated via immunohistochemistry (IHC) test. Cox regression model was used to investigate prognostic markers to relapse-free survival (RFS).

Results

50.9% patients were considered as pCR responder in PCH cohort, whereas only 25.9% of patients experienced pCR in PC cohort (P < 0.001). HER2 loss were more frequently shown in PCH cohort with a proportion of 19.8%, compared to 9.4% in PC cohort (P = 0.009). In PCH cohort, patients with a loss of HER2 expression tended to have a higher risk of relapse compared to patients with maintained HER2 expression (HR = 2.639, 95% CI 1.103–6.311, P = 0.029). However, it did not correlate to patient outcome in the PC cohort (P = 0.296). Loss of HER2 was also correlated to ER conversion in PCH cohort.

Conclusion

Our study has provided new evidence that anti-HER2 treatment has a significant impact on HER2 loss. Far more importantly, the loss of HER2 amplification could identify non-pCR patients with high risk of disease relapse, which might help in tailoring following systemic treatment.

     

Monosomy 17 in potentially curable <Emphasis Type="Italic">HER2</Emphasis>-amplified breast cancer: prognostic and predictive impact

Purpose

HER2 copy number by fluorescence in situ hybridization (FISH) is typically reported relative to the centromere enumeration probe 17 (CEP17). HER2/CEP17 ratio could be impacted by alterations in the number of chromosome 17 copies. Monosomy of chromosome 17 (m17) is found in ~ 1900 cases of early-stage HER2-positive breast cancer annually in the United States; however, the efficacy of HER2-directed trastuzumab therapy in these patients is not well characterized. Here, we retrospectively identified HER2-amplified, stage I–III breast cancers with m17 and characterized the impact of trastuzumab treatment.

Methods

From January 1, 2000 to June 1, 2011, we identified 99 women with HER2-amplified m17 breast cancers, as defined by a CEP17 signal of < 1.5 per nucleus and a HER2/CEP17 ratio of ≥ 2.0.

Results

Most HER2-amplified m17 patients were treated with trastuzumab plus chemotherapy (51%, n = 50), whereas 31% (n = 31) received chemotherapy alone and 18% (n = 18) received no chemotherapy. The 4-year overall survival (OS) was superior with trastuzumab compared to chemotherapy alone or no chemotherapy (100 vs. 93 vs. 81%, respectively; p = 0.005). OS was not influenced by estrogen/progesterone-receptor (ER/PR) status, tumor stage, or degree of FISH positivity. A proportion of patients who would be considered HER2-negative by standard immunohistochemistry staging criteria (0–1+) were HER2 amplified by FISH.

Conclusions

In the largest series reported to date, patients with HER2-amplified m17 cancers treated with trastuzumab have outcomes comparable to patients from the large phase III adjuvant trastuzumab trials who were HER2-positive, supporting the critical role of HER2-directed therapy in this patient population.

     

Bright-field HER2 dual in situ hybridization (DISH) assay on breast cancer cell blocks: a comparative study with histological sections

Background

HER2 testing for samples from recurrent or metastatic disease is recommended by the 2013 update of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines and cytological analysis can be applied to several types of metastatic lesions. However, the practical method to assess the HER2 testing of breast cancer cytology specimens has yet to be resolved. Therefore, we conducted the bright-field HER2 dual in situ hybridization (DISH) assay on cell blocks (CBs) prepared from breast cancer cell samples as a validation study before clinical use.

Methods

CBs were prepared from tumor cell samples collected from 54 surgically excised breast tumors. The cells were fixed in 10 % buffered formalin for 16–28 h, and embedded in paraffin. The INFORM HER2/neu Dual ISH DNA Probe Cocktail was used for the DISH assay on the Ventana BenchMark ULTRA (Roche Diagnostics).

Results

Successful results were obtained in 51 of 54 CB specimens, and the results from the CB specimens were in agreement with those from the histological sections in 48 of the 51 cases (concordance rate, 94 %; kappa, 0.846). The intraclass correlation coefficient (ICC) between the CB and histological specimens in the continuous HER2/CEP17 signal count ratio was 0.89 (95 % CI 0.81–0.93), and the Pearson’s CC was 0.91 (95 % CI 0.85–0.94).

Conclusion

The HER2 DISH assay, utilizing 10 % buffered formalin-fixed CB, would be a reliable and ideal method to assess the HER2 gene status of breast cancer cytological specimens.

     

Docetaxel,cyclophosphamide, and trastuzumab as neoadjuvant chemotherapy for HER2-positive primary breast cancer

Background

The standard primary systemic therapy for human epidermal growth factor receptor 2-positive (HER2+) breast cancer is anthracyclines and/or taxanes combined with trastuzumab, which demonstrates a high pathological complete response (pCR). A pCR is a predictive marker of prognosis. However, results slightly differ, depending on the hormone receptor status. The efficacy and tolerability of docetaxel, cyclophosphamide, and trastuzumab (HER-TC) as neoadjuvant chemotherapy (NAC) remain unclear. We performed a prospective multicenter study of HER-TC NAC for HER2+ primary breast cancer.

Methods

Eligible patients had a clinical diagnosis of HER2+ invasive breast cancer greater than 1 cm but less than 7 cm and a tumor stage of N0 or N1. They were diagnosed between July 2011 and February 2014. For NAC, four cycles of HER-TC (6 mg/kg loading dose, 8 mg/kg, 75, and 600 mg/m²) were administered intravenously every 3 weeks. We investigated the pCR of the primary breast tumors. A pCR was defined as no histological evidence of invasive carcinoma or the appearance of only ductal carcinoma in situ.

Results

We enrolled 42 patients. The completion rate for four cycles of HER-TC was 97.6 % (41/42 patients). The overall pCR rate was 43.9 % (18/41 patients). The pCR rate for patients with the luminal HER2 subtype [estrogen receptor (ER)-positive+, HER2+] and the HER2-enriched subtype (ER?, HER2+) was 40.0 % (8/20 patients) and 47.6 % (10/21 patients), respectively. A pCR was achieved with nearly the same probability for each subtype.

Conclusions

Four cycles of HER-TC may be a NAC option for HER2-positive breast cancer.

     

Highly sensitive detection of <Emphasis Type="Italic">ESR1</Emphasis> mutations in cell-free DNA from patients with metastatic breast cancer using molecular barcode sequencing

Purpose

We aimed to develop a highly sensitive method to detect ESR1 mutations in cell-free DNA (cfDNA) using next-generation sequencing with molecular barcode (MB–NGS) targeting the hotspot segment (c.1600–1713).

Methods

The sensitivity of MB–NGS was tested using serially diluted ESR1 mutant DNA and then cfDNA samples from 34 patients with metastatic breast cancer were analyzed with MB–NGS. The results of MB–NGS were validated in comparison with conventional NGS and droplet digital PCR (ddPCR).

Results

MB–NGS showed a higher sensitivity (0.1%) than NGS without barcode (1%) by reducing background errors. Of the cfDNA samples from 34 patients with metastatic breast cancer, NGS without barcode revealed seven mutations in six patients (17.6%) and MB–NGS revealed six additional mutations including three mutations not reported in the COSMIC database of breast cancer, resulting in total 13 ESR1 mutations in ten patients (29.4%). Regarding the three hotspot mutations, all the patients with mutations detected by MB–NGS had identical mutations detected by droplet digital PCR (ddPCR), and mutant allele frequency correlated very well between both (r = 0.850, p < 0.01). Moreover, all the patients without these mutations by MB–NGS were found to have no mutations by ddPCR.

Conclusion

In conclusion, MB–NGS could successfully detect ESR1 mutations in cfDNA with a higher sensitivity of 0.1% than conventional NGS and was considered as clinically useful as ddPCR.

     

An independent survival prognostic role for human epidermal growth factor receptor 2 in gastric cancer: evidence from a meta-analysis

Background

Some studies have suggested that human epidermal growth factor receptor 2 (HER2) positive is associated with poor outcomes in gastric cancer (GC), whereas another inconsistent studies make the situation confused. This meta-analysis was performed to determine whether HER2 played an independent prognostic role in clinicopathological characteristics and survival outcomes of GC.

Patients and methods

Combination of GC and human epidermal growth factor 2 or HER2 or HER2/neu or erbB-2 or cerbB-2 or c-erbB2 or CD340 or p185 were used as key words. Data were compared according to the HER2 status. Time-to-event outcomes of overall survival (OS) were analyzed using Hazard Ratios (HRs) with fixed effect, while 5-year survival rate and clinicopathological factors were performed using odd ratios (OR) with random effect.

Results

Nighteen trials, from 1986 to October 2013, were identified by two independent authors. A total of 6344 GC patients were included in this meta-analysis, with 1148 HER2 protein overexpression or gene amplification. Comparison of 5-year survival of patients with HER2-positive status versus HER2-negative status showed that OR was 0.58 [95% confidence interval (CI), 0.37–0.91], and the result was significant (P = 0.02). The survival outcome of HER2 protein overexpression or gene amplification patients was worse than those with normal HER2 (HR 1.15; 95% CI 1.12–1.18; P < 0.00001). However, the difference of III–IV stage ratio between HER2-positive and HER2-negative patients was not significant (OR 1.44; 95% CI 0.95–2.18; P = 0.09) even in the subgroup analysis of Asia (P = 0.12 and Europe (P = 0.51).

Conclusion

HER2 protein overexpression or gene amplification in GC patients is associated with a poor survival outcome, and may play a role in GC tumorigenesis.

     

Clinicopathological factors associated with HER2 status in gastric cancer: results from a prospective multicenter observational cohort study in a Japanese population (JFMC44-1101)

Background

Human epidermal growth factor (HER) 2 positivity and its association with clinicopathological factors remain unclear in Japanese gastric cancer (GC) patients. We performed a prospective, multicenter, observational cohort study to evaluate HER2 protein expression and gene amplification in Japanese metastatic and recurrent GC patients, and explored its correlations with clinicopathological features.

Methods

HER2 protein expression and gene amplification were centrally assessed in formalin-fixed, paraffin-embedded GC tissue by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Patient information was collected, and associations between clinicopathological factors and HER2 positivity (IHC score 3+ and/or FISH positive) and low HER2 expression (IHC score 0/FISH positive or IHC score 1+/FISH positive) were examined.

Results

From September 2011 to June 2012, 1461 patients were registered across 157 sites, and the HER2 status of 1427 patients was evaluated. The rate of HER2 positivity was 21.2 %, whereas the rate of high HER2 expression (IHC score 2+/FISH positive or IHC score 3+) was 15.6 % and that of low HER2 expression was 7.0 %. Multiple logistic regression analysis identified intestinal type, absence of peritoneal metastasis, and hepatic metastasis as significant independent factors related to HER2 positivity. The intestinal type was confirmed to be the GC subtype predominantly associated with lower HER2 expression. Sampling conditions including number of biopsy samples, formalin concentration, and formalin-fixation time did not significantly affect HER2 positivity.

Conclusions

HER2 expression in Japanese patients was comparable to that in other populations examined. Intestinal type was an independent factor related to HER2 positivity and low HER2 expression.

     

The yield of full <Emphasis Type="Italic">BRCA1</Emphasis>/<Emphasis Type="Italic">2</Emphasis> genotyping in Israeli high-risk breast/ovarian cancer patients who do not carry the predominant mutations

Purpose

Patients treated with trastuzumab for HER2-positive metastatic breast cancer (HER2+MBC) are living longer, but there is little information on their outcomes and treatment experience beyond the median survival from clinical trials and real-world observational studies. We aim to describe the real-world treatment patterns and overall survival (OS) for women surviving five or more years from initiation of trastuzumab for HER2+MBC.

Methods

This is a retrospective, whole-of-population cohort study of women initiating trastuzumab for HER2+MBC between 2001 and 2011, followed to 2016. We defined long-term survivors (LTS) as those patients surviving?≥?5 years from trastuzumab initiation. We used dispensing claims to describe timing of cancer treatments used by LTS and to estimate time on and off HER2-targeted therapies, and OS from trastuzumab initiation for HER2+MBC.

Results

Of 4177 women initiating trastuzumab for HER2+MBC, 1082 (26%) survived ≥?5 years. Median age for LTS was 54 years (IQR 46–63). At a median follow-up of 9.4 years, 36% of LTS died; their conditional probability of surviving an additional 5 years was 55%. Median time on trastuzumab and all HER2-targeted therapy was 58.9 months (27.6–88.1) and 69.1 months (35.6–124.5), respectively. 85% of LTS had a period off HER2 therapy, lasting a median of 30.4 months (8.2–NR).

Conclusions

LTS generally receive HER2-targeted therapies for periods of time longer than in clinical trials, but most LTS also had breaks in treatment. More research is needed to understand the effects of long-term treatment and to identify patients who may be able to safely discontinue HER2-targeted therapy.

     

Phase II trial of dacomitinib in patients with HER2-positive gastric cancer

Background

Dacomitinib, an irreversible panHER inhibitor, shows significant preclinical antitumor activity in human epidermal growth factor receptor 2 (HER2)-positive gastric cancer (GC). The aim of this study was to evaluate the clinical activity of dacomitinib and discover potential biomarkers in HER2-positive GC patients.

Methods

We enrolled previously treated advanced HER2-positive GC [HER2 FISH (+) or HER2 IHC 3+] patients. The patients received dacomitinib 45 mg once daily.

Results

A total of 27 patients were enrolled. The number of prior chemotherapy regimens was 1 in 7 patients (26 %), 2 in 9 patients (33 %), and more than 2 in 11 patients (41 %). Seven patients had received prior anti-HER2 therapy. The 4-month progression-free survival (PFS) rate was 22.2 % and median PFS was 2.1 months (95 % CI, 2.3–3.4) There were 2 partial response (PRs) and 9 stable disease (SDs), resulting in 7.4 % (95 % CI, 0–17.5 %) of response rate (RR) and 40.7 % (95 % CI, 21.9–59.6 %) of disease control rate (DCR). Eleven patients (41 %) showed some degree of tumor shrinkage. Overall survival was 7.1 months (95 % CI, 4.4–9.8). The most common toxicities were skin rash, diarrhea, and fatigue, most of which were grade 1 or 2. The C_trough of dacomitinib was lower in gastrectomy patients than nongastrectomy patients. Higher serum levels of HER2 extracellular domain (ECD) and lower levels of soluble E-cadherin (sECAD) correlated with higher dacomitinib activity.

Conclusions

Dacomitinib functions as a single agent in HER2-positive GC patients with a tolerable safety profile. HER2 ECD and sECAD have the potential to be biomarkers for patient selection in a panHER inhibition strategy for HER2-positive GC. (ClinicalTrials.gov: NCT01152853).

     

HER4 expression in estrogen receptor-positive breast cancer is associated with decreased sensitivity to tamoxifen treatment and reduced overall survival of postmenopausal women

Background

The sensitivity of estrogen receptor-positive breast cancers to tamoxifen treatment varies considerably, and the molecular mechanisms affecting the response rates are manifold. The human epidermal growth factor receptor-related receptor HER2 is known to trigger intracellular signaling cascades that modulate the activity of coregulators of the estrogen receptor which, in turn, reduces the cell sensitivity to tamoxifen treatment. However, the impact of HER2-related receptor tyrosine kinases HER1, HER3, and, in particular, HER4 on endocrine treatment is largely unknown.

Methods

Here, we retrospectively evaluated the importance of HER4 expression on the outcome of tamoxifen- and aromatase inhibitor-treated estrogen receptor-positive breast cancer patients (n =?258). In addition, we experimentally analyzed the efficiency of tamoxifen treatment as a function of HER4 co-expression in vitro.

Results

We found a significantly improved survival in tamoxifen-treated postmenopausal breast cancer patients in the absence of HER4 compared with those with pronounced HER4 expression. In accordance with this finding, the sensitivity to tamoxifen treatment of estrogen and HER4 receptor-positive ZR-75-1 breast cancer cells can be significantly enhanced by HER4 knockdown.

Conclusion

We suggest an HER4/estrogen receptor interaction that impedes tamoxifen binding to the estrogen receptor and reduces treatment efficiency. Whether the sensitivity to tamoxifen treatment can be enhanced by anti-HER4 targeting needs to be prospectively evaluated.

     

Optimizing HER2-Directed Therapy in Early-Stage Breast Cancer

Purpose of Review

HER2-positive early breast cancer has been revolutionized by the development of HER2-directed therapy, which has significantly reduced breast cancer recurrence risk and improved overall survival. Here, we review the available treatment options for this patient population and discuss how we might individualize therapy in the future to optimize the balance of efficacy and toxicity.

Recent Findings

The addition of pertuzumab to a trastuzumab-based adjuvant regimen improves pathologic complete response rates and invasive disease-free survival (DFS). Addition of neratinib for patients with high-risk disease also contributes to improved DFS.

Summary

Current data supports use of dual HER2-directed therapy in combination with chemotherapy, as well as extended HER2-directed therapy (beyond 1 year), in those with high-risk HER2-positive early breast cancer. Ongoing studies aim to identify biomarkers of response and resistance to standard approaches, as well as identify those who might benefit from a chemotherapy-free treatment paradigm.