Quantification of Cell-Free HER-2 DNA in Plasma from Breast Cancer Patients: Sensitivity for Detection of Metastatic Recurrence and Gene Amplification.

The purpose of this study was to quantify the free-circulating plasma HER-2 DNA (cfHER-2 DNA) and to assess the ability of analysis to discriminate between patients with primary breast cancer and healthy controls in order to detect metastatic recurrence in comparison with serum HER-2 protein and also HER-2 gene amplification. The study population consisted of 100 patients with primary breast cancer and 50 healthy female donors. An additional 22 patients with metastases were subsequently included. cfHER-2 DNA was quantified with a quantitative PCR method together with a reference gene. RESULTS: Using a cut-off of 2.5 for the ratio of the cfHER-2 DNA/reference gene, three (of 15) tissue HER-2-positive patients had a ratio >2.5 prior to the detection of metastatic disease. In the post-metastatic/pre-chemotherapy setting, 11 (of 23) tissue HER-2-positive patients with metastases had a ratio >2.5. There was no difference between absolute preoperative cfHER-2 DNA values for patients with primary breast cancer and those for healthy controls. There was no difference between cfHER-2 DNA values taken within nine months of development of the metastatic disease and the levels in patients without metastases, but there was a significant difference in the corresponding serum HER-2 protein levels in the tissue HER-2-positive patient group. CONCLUSION: Amplified HER-2 DNA can be detected in plasma when using a ratio between cfHER-2 DNA and a reference gene. cfHER-2 DNA could not be used to discriminate between patients with primary breast cancer and healthy controls, and could not predict the development of metastatic disease.

Serum HER-2: sensitivity, specificity, and predictive values for detecting metastatic recurrence in breast cancer patients.

PURPOSE: The aim of this study was to determine the sensitivity, specificity, and predictive values of serum HER-2 for detecting metastatic recurrence in breast cancer patients. METHODS: In the period 2004-2009, serum HER-2 was measured in 1,348 patients with breast cancer: 837 during routine controls at the Oncology Department and 511 newly diagnosed. The patients with positive serum HER-2, all the newly diagnosed and 1/5 of the patients with negative serum HER-2 were followed with serum HER-2 measurements every 3-12 months using the ADVIA Centaur assay. Tissue HER-2 status was determined by IHC and FISH. Patients with a single serum HER-2 value above 15 µg/L were considered serum positive. Metastases were diagnosed according to the routine clinical methods using imaging/biopsy. RESULTS: Of the 862 patients included, 21 had unavailable medical records and were excluded. Patients with unknown tissue status (218), missing blood sample before recurrence (74), or presenting with primary metastatic disease (9) were also excluded. Blood samples before the detection of metastatic recurrence were available in 154 tissue HER-2-positive and in 386 tissue HER-2-negative patients. The sensitivity, specificity, positive and negative predictive values in tissue HER-2-positive patients with values above 15 µg/L were 69 % (95 % CI 53-80 %), 71 % (62-78), 47 % (35-59), and 86 % (77-91), respectively. Combining the cutoff value of 15 µg/L with a delta value of >100 % increase from individual baseline after primary therapy, or increasing the cutoff to 32 µg/L raises the specificity to 96 %, but lowers the sensitivity to 50 and 47 %, respectively. Preoperative serum HER-2 values were accessible in 69 tissue-positive patients, but no significant association was found with later development of metastases. The sensitivity, specificity, positive and negative predictive values in tissue HER-2-negative patients with values above 15 µg/L were 33 % (21-47), 77 % (73-82), 18 % (12-27), and 88 % (84-91), respectively. CONCLUSIONS: Monitoring tissue HER-2-positive breast cancer patients with serum HER-2 has a sufficient sensitivity to detect metastatic recurrence, while its use in monitoring of tissue HER-2-negative patients is unsatisfactory.

Sensitivity of CA 15-3, CEA and serum HER2 in the early detection of recurrence of breast cancer.

BACKGROUND: The aim of this project was to investigate the sensitivity of CA 15-3, CEA and HER2 in the early diagnosis of metastatic breast cancer. METHODS: Serial serum values of CA 15-3, CEA and HER2 were determined in 107 patients with recurrence after breast cancer. Fifteen of the patients had primary disseminated disease, nine patients only developed local recurrence during the follow-up period and the remaining 83 developed distant metastases. RESULTS: In the group of patients with distant metastatic disease (n=83), elevated serum levels of CA 15-3 (>32.4 U/mL), CEA (>2.5 µg/L for non-smokers and >10 µg/L for smokers) and HER2 (>15 µg/L) were found in 49.4%, 38.6% and 32.5%, respectively, at the time of diagnosis of recurrence. CA 15-3 was significantly better than HER2 (p=0.027). The most sensitive combination was obtained using CA 15-3/CEA (60.2%) or CA 15-3/HER2 (57.8%). Combining all three tumour markers raised the sensitivity to 63.9%. In the subgroup of patients with tissue HER2+ tumours, the sensitivity of HER2 increased to 55.6%. The best combination in this group was CEA/HER2 (66.7%). In the subgroup of patients with tissue HER2- tumours, CA 15-3 was significantly better. The best combination was CA 15-3/HER2 or CA 15-3/CEA with a sensitivity of 55.8% and 59.6%, respectively. CONCLUSIONS: The combination of several tumour markers enhances the sensitivity for detection of metastatic breast cancer. We recommend HER2 or the combination of CEA and HER2 in tissue HER2+ and CA 15-3 or the combination of CA 15-3 and CEA in tissue HER2-.

Serum HER-2 predicts response and resistance to trastuzumab treatment in breast cancer.

BACKGROUND: Serum HER2 (S-HER2) was approved in 2003 by the US Food and Drug Administration (FDA) for monitoring trastuzumab treatment in tissue HER2 positive breast cancer patients. Information of the value of S-HER2 is scarce. We hypothesised that S-HER2 would reflect the clinical effect of trastuzumab. METHODS: We followed 48 patients eligible for trastuzumab treatment for up to 6 years or until death. S-HER2 was measured on an ADVIA Centaur System and S-Trastuzumab was measured by an in-house developed fluorescent enzyme immunoassay system on the ImmunoCap 100. RESULTS: A decrease in S-HER2 of ≥ 20% was correlated to no progression in the disease in 20 out of 21 clinical courses (p<0.0001). An increase in S-HER2 of ≥ 20% was correlated to progression in the disease in 40 out of 44 clinical courses (p<0.0001). Patients with no recurrence after trastuzumab treatment (n=18) had a median S-HER2 concentration of 10.5 µg/L, whereas patients alive with recurrence (n=13) had a median S-HER2 of 20.1 µg/L (p=0.002). Patients who died prompted by recurrence (n=17) had a median S-HER2 of 232.4 µg/L at latest measurement before death (p=<0.0001) compared to patients without recurrence. In two patients with S-HER2 values above 1000 µg/L the concentrations of S-trastuzumab were measured below the target trough concentration in serum of 10 mg/L. CONCLUSIONS: Decreasing values of S-HER2 predicts response to treatment whereas increasing levels predict resistance. S-HER2 above 1000 µg/L warns that standard doses of trastuzumab may be insufficient as reflected by low concentrations of S-trastuzumab.

Serum HER-2 concentrations for monitoring women with breast cancer in a routine oncology setting.

BACKGROUND: The purpose of this study was to determine the positive predictive value (PPV) of positive serum human epidermal growth factor receptor-2 (HER-2) for monitoring women with breast cancer following diagnosis and treatment in a routine clinical setting. METHODS: Serum HER-2 was measured in 1348 patients with breast cancer: 837 during routine oncology clinic visits and 511 following new diagnosis. All patients with positive serum HER-2, 1/5 of negative patients from the oncology clinic, and all the newly diagnosed were followed; a total of 862 patients. Serum HER-2 was measured using the Bayer ADVIA Centaur assay. Tissue HER-2 was determined using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). IHC +3 or IHC +2 and FISH>2.0 were positive. Patients were considered to have positive serum HER-2 when at least two values were >15 ng/mL. Recurrence, progression and regression were diagnosed according to usual clinical practice. Serum HER-2 concentrations did not contribute to diagnostic decision-making or selection of treatment. RESULTS: From January 2004 to January 2009, 149 patients were found to have positive serum HER-2. Of these, 35 were tissue HER-2 positive at surgery, 69 tissue-negative and 45 were not determined. Fifty-five of 149 that were serum HER-2 positive (37%, 95% CI: 29-45) had metastases. Among the 35 tissue-positive patients, 25 had recurrence in the form of metastases and there was good correlation between recurrence/progression and increase in serum HER-2 (p<0.0003). There was also a high correlation between effect of treatment and decline in serum HER-2 (p<0.0003). Of the 69 tissue-negative patients, 29 had recurrence in the form of metastases, and there was good correlation with serum HER-2 levels (p<0.000004). In this routine application of serum HER-2, the PPV for metastases recurrence detection in both tissue-positive and tissue-negative was 54 of 104 (52%, 95% CI: 42%-62%), in tissue-positive 25 of 35 (71%, 95% CI: 54%-85%), in tissue-negative 29 of 69 (42%, 95% CI: 30%-54%). The lead time of increases in serum HER-2 before recurrence could be determined in ten tissue-positive patients was 3-24 months (mean 11.3 months), when compared to standard clinical imaging methods. CONCLUSIONS: Serum HER-2 is a useful marker for the detection of recurrence of breast cancer and for monitoring the effect of treatment, especially in tissue HER-2 positive patients.