Fibrotic activity quantified in serum by measurements of type III collagen pro-peptides can be used for prognosis across different solid tumor types.

Due to activation of fibroblast into cancer-associated fibroblasts, there is often an increased deposition of extracellular matrix and fibrillar collagens, e.g. type III collagen, in the tumor microenvironment (TME) that leads to tumor fibrosis (desmoplasia). Tumor fibrosis is closely associated with treatment response and poor prognosis for patients with solid tumors. To assure that the best possible treatment option is provided for patients, there is medical need for identifying patients with high (or low) fibrotic activity in the TME. Measuring unique collagen fragments such as the pro-peptides released into the bloodstream during fibrillar collagen deposition in the TME can provide a non-invasive measure of the fibrotic activity. Based on data from 8 previously published cohorts, this review provides insight into the prognostic value of quantifying tumor fibrosis by measuring the pro-peptide of type III collagen in serum of a total of 1692 patients with different solid tumor types and discusses the importance of tumor fibrosis for understanding prognosis and for potentially guiding future drug development efforts that aim at overcoming the poor outcome associated with a fibrotic TME.

Cellular Fitness Phenotypes of Cancer Target Genes from Oncobiology to Cancer Therapeutics.

To define the growing significance of cellular targets and/or effectors of cancer drugs, we examined the fitness dependency of cellular targets and effectors of cancer drug targets across human cancer cells from 19 cancer types. We observed that the deletion of 35 out of 47 cellular effectors and/or targets of oncology drugs did not result in the expected loss of cell fitness in appropriate cancer types for which drugs targeting or utilizing these molecules for their actions were approved. Additionally, our analysis recognized 43 cellular molecules as fitness genes in several cancer types in which these drugs were not approved, and thus, providing clues for repurposing certain approved oncology drugs in such cancer types. For example, we found a widespread upregulation and fitness dependency of several components of the mevalonate and purine biosynthesis pathways (currently targeted by bisphosphonates, statins, and pemetrexed in certain cancers) and an association between the overexpression of these molecules and reduction in the overall survival duration of patients with breast and other hard-to-treat cancers, for which such drugs are not approved. In brief, the present analysis raised cautions about off-target and undesirable effects of certain oncology drugs in a subset of cancers where the intended cellular effectors of drug might not be good fitness genes and that this study offers a potential rationale for repurposing certain approved oncology drugs for targeted therapeutics in additional cancer types.

Higher serum PD-L1 level predicts increased overall survival with lapatinib versus trastuzumab in the CCTG MA.31 phase 3 trial.

BACKGROUND: The purpose of this retrospective biomarker study of the Canadian Cancer Trials Group (CCTG) MA.31 randomized phase 3 trial (lapatinib vs trastuzumab) of HER2-positive metastatic breast cancer (MBC) was to evaluate the prognostic and predictive biomarker utility of pretreatment serum programmed death ligand 1 (PD-L1) levels. METHODS: CCTG MA.31 accrued 652 HER2-positive patients; 387 had serum available (185 in the trastuzumab arm and 202 in the lapatinib arm). The Ella immunoassay platform (ProteinSimple, San Jose, California) was used to quantitate serum PD-L1 levels. Stepwise forward Cox multivariable analyses were performed for progression-free survival and overall survival (OS). RESULTS: In the whole trial population, continuous pretreatment serum PD-L1 levels were not associated with OS. However, within the trastuzumab arm, a higher continuous pretreatment serum PD-L1 level was significant for shorter OS (hazard ratio [HR], 3.85; P = .04), but within the lapatinib arm, pretreatment serum PD-L1 was not associated with OS (P = .37). In the whole trial, in a multivariable analysis for OS, serum PD-L1 (median cut point) remained a significant independent covariate (HR, 2.38; P = .001). There was a significant interaction between treatment arm and continuous serum PD-L1 (bootstrap method; P = .0025): at or above 214.2 pg/mL (the 89th percentile), serum PD-L1 was associated with significantly shorter OS with trastuzumab treatment versus lapatinib treatment. CONCLUSIONS: In the CCTG MA.31 trial, serum PD-L1 was a significant predictive factor: a higher pretreatment serum PD-L1 level was associated with shorter OS with trastuzumab treatment but with longer OS with lapatinib treatment. Immune evasion may decrease the effectiveness of trastuzumab therapy. Further evaluation of elevated serum PD-L1 in advanced breast cancer is warranted to identify patients with HER2-positive MBC who may benefit from novel immune-targeted therapies in addition to trastuzumab.

Collagen fragments quantified in serum as measures of desmoplasia associate with survival outcome in patients with advanced pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) patients have poor prognosis and poor response to treatment. This is largely due to PDAC being associated with a dense and active stroma and tumor fibrosis (desmoplasia). Desmoplasia is characterized by excessive degradation and formation of the extracellular matrix (ECM) generating collagen fragments that are released into circulation. We evaluated the association of specific collagen fragments measured in pre-treatment serum with outcome in patients with PDAC. Matrix metalloprotease (MMP)-degraded type I collagen (C1M), type III collagen (C3M), type IV collagen (C4M) and a pro-peptide of type III collagen (PRO-C3) were measured by ELISA in pre-treatment serum from a randomized phase 3 clinical trial of patients with stage III/IV PDAC treated with 5-fluorouracil based therapy (n = 176). The collagen fragments were evaluated for their correlation (r, Spearman) with serum CA19-9 and for their association with overall survival (OS) based on Cox-regression analyses. In this phase 3 PDAC trial, pre-treatment serum collagen fragment levels were above the reference range for 67%-98% of patients, with median values in PDAC approximately two-fold higher than reference levels. Collagen fragment levels did not correlate with CA19-9 (r = 0.049-0.141, p = ns). On a continuous basis, higher levels of all collagen fragments were associated with significantly shorter OS. When evaluating degradation (C3M) and formation (PRO-C3) of type III collagen further, higher PRO-C3 was associated with poor OS (>25th percentile cut-point, HR = 2.01, 95%CI = 1.33-3.05) and higher C3M/PRO-C3 ratio was associated with improved OS (>25th percentile cut-point, HR = 0.53, 95%CI = 0.34-0.80). When adjusting for CA19-9 and clinical covariates, PRO-C3 remained significant (HR = 1.65, 95%CI = 1.09-2.48). In conclusion, collagen remodeling quantified in pre-treatment serum as a surrogate measure of desmoplasia was significantly associated with OS in a phase 3 clinical PDAC trial, supporting the link between desmoplasia, tumorigenesis, and response to treatment. If validated, these biomarkers may have prognostic and/or predictive potential in future PDAC trials.

High turnover of extracellular matrix reflected by specific protein fragments measured in serum is associated with poor outcomes in two metastatic breast cancer cohorts.

Increased extracellular matrix (ECM) formation and matrix metalloprotease (MMP)-mediated ECM degradation are parts of tumorgenesis and generates collagen fragments that are released into circulation. We evaluated the association of specific collagen fragments measured in serum with outcomes in two independent metastatic breast cancer (MBC) cohorts. ELISAs were used to measure C1M (MMP-generated type I collagen fragment), C3M (MMP-generated type III collagen fragment), C4M (MMP-generated type IV collagen fragment), and PRO-C3 (pro-peptide of type III collagen) in pretreatment serum from a phase 3 randomized clinical trial of second-line hormone therapy (HR+, n = 148), and a first-line trastuzumab-treated cohort (HER2+, n = 55). All sites of metastases were included. The collagen fragments were evaluated by Cox-regression analysis for their association with time-to-progression (TTP) and overall survival (OS). In the HR+ cohort, higher C1M and C3M levels (75th percentile cut-off) were associated with shorter TTP; all fragments were associated with shorter OS. In the HER2+ cohort, higher levels of all fragments were associated with shorter TTP; higher PRO-C3 was associated with shorter OS. In multivariate analysis of the HR+ trial for OS, higher levels of all fragments were significant for reduced OS when added separately (C1M HR = 2.1, p < 0.001; C3M HR = 1.8, p = 0.028; C4M HR = 1.8, p = 0.018; PRO-C3 HR = 1.8, p = 0.017); none other clinical covariates were significant. In conclusion, collagen fragments quantified in pretreatment serum was associated with shorter TTP and OS in two independent MBC cohorts receiving systemic therapy. If validated, quantification of ECM remodeling in serum has potential as prognostic and/or predictive biomarkers in MBC.

Impact of serum HER2, TIMP-1, and CAIX on outcome for HER2+ metastatic breast cancer patients: CCTG MA.31 (lapatinib vs. trastuzumab).

BACKGROUND: The lapatinib-taxane combination led to shorter PFS than trastuzumab-taxane in HER2+ metastatic breast cancer. We investigated the prognostic and predictive effects of pretreatment serum HER2, CAIX, and TIMP-1. METHODS: MA.31 accrued 652 patients; 537 (82%) were centrally confirmed HER2+. Biomarkers were categorized for univariate and multivariable predictive investigations with a median cut-point, ULN cut-points (15 ng/ml for HER2; 506 pg/ml for CAIX; 454 pg/ml for TIMP-1), and custom cut-points (30 and 100 ng/ml for HER2). Stratified step-wise forward Cox multivariable analysis examined continuous and categorical effects of biomarkers on PFS in the ITT and central HER2+ populations; central HER2+ biomarker results are shown. RESULTS: Serum was banked for 472 (72%) of 652 patients. Higher serum HER2 (>median; >15; >30; or >100 ng/ml; p = 0.05-0.002); higher CAIX (>median; >506 pg/ml; p = 0.02; p = 0.001); and higher TIMP-1 (> median; > 454 pg/ml; p = 0.001; p = 0.02) had shorter univariate PFS. In multivariable analysis, higher continuous TIMP-1 was associated with significantly shorter PFS: HR = 1.001 (95% CI = 1.00-01.002; p = 0.004). Continuous serum HER2 and CAIX were not significantly associated with PFS. HER2 of 15 ng/ml or higher had shorter PFS (p = 0.02); higher categorical CAIX had shorter PFS (p = 0.01-0.08). Interaction terms of HER2, CAIX, and TIMP-1 with treatment were not significant; the predictive test power was low. CONCLUSIONS: Higher levels of serum TIMP-1, CAIX, and HER2 were significant prognostic biomarkers of shorter PFS. We found no significant interaction between serum biomarkers and response to lapatinib versus trastuzumab. Evaluation of TIMP-1 and CAIX-targeted therapy in addition to HER2-targeted therapy appears warranted in patients with elevated serum levels of these biomarkers.

Osteoporosis therapy and outcomes for postmenopausal patients with hormone receptor-positive breast cancer: NCIC CTG MA.27.

BACKGROUND: Breast cancer patients in the MA.27 trial had similar outcomes with steroidal aromatase inhibitor (AI) exemestane and nonsteroidal anastrozole. AIs increase the risk of osteoporosis. This study examined the effects of self-reported osteoporosis and osteoporosis therapy (OPT) on outcomes. METHODS: The MA.27 phase 3 adjuvant trial enrolled 7576 postmenopausal women. The primary outcome was event-free survival (EFS), and the secondary outcome was distant disease-free survival (DDFS). Patients were permitted bisphosphonates to prevent or treat osteopenia/osteoporosis. In a multivariate, stratified Cox regression, factors were significant with a 2-sided Wald test P value ≤ .05. RESULTS: Osteoporosis was reported at the baseline by 654 of the 7576 women (8.6%) and in total by 1294 patients. Oral OPT was received at the baseline by 815 of the 7576 women (10.8%) and in total by 2711 patients (36%). With a median follow-up of 4.1 years, 693 EFS events (9.15%) and 321 DDFS events (4.2%) occurred. Osteoporosis was not associated with EFS or DDFS. Few EFS events occurred before the initiation of OPT, with no substantive evidence of a time-differing effect on outcomes (nonproportional hazards). OPT (yes vs no) was significantly associated with improved EFS (hazard ratio [HR] for yes vs no, 0.67; 95% confidence interval [CI], 0.57-0.80; P < .001) and DDFS (HR, 0.57; 95% CI, 0.44-0.73; P <. 001). Time-differing (time-dependent) OPT was not (EFS; P = .45). OPT did not alter the incidence of visceral-only metastasis (P = .31). CONCLUSIONS: Oral OPT, administered to postmenopausal breast cancer patients receiving adjuvant AI therapy, was associated with improved EFS and DDFS; the time of OPT initiation (a time-dependent effect) did not affect the outcome. OPT did not alter the risk of visceral metastasis. Cancer 2017;123:2444-51. © 2017 American Cancer Society.

Would screening for lung cancer benefit 75- to 84-year-old residents of the United States?

BACKGROUND: The National Lung Screening Trial demonstrated that screening for lung cancer improved overall survival (OS) and reduced lung cancer mortality in the 55- to 74-year-old age group by increasing the proportion of cancers detected at an early stage. Because of the increasing life expectancy of the American population, we investigated whether screening for lung cancer might benefit men and women aged 75-84 years. MATERIALS/METHODS: Rates of non-small cell lung cancer (NSCLC) from 2000 to 2009 were calculated in both younger and older age groups using the surveillance epidemiology and end reporting database. OS and lung cancer-specific survival (LCSS) in patients with Stage I NSCLC diagnosed from 2004 to 2009 were analyzed to determine the effects of age and treatment. RESULTS: The per capita incidence of NSCLC decreased in the 55-74 cohort, but increased in the 75-84 cohort over the study period. Crude lung cancer death rates in the two age groups who had no specific treatment were 39.5 and 44.9%, respectively. These rates fell in both age groups when increasingly aggressive treatment was used. Rates of OS and LCSS improved significantly with increasingly aggressive treatment in the 75-84 age group. The survival benefits of increasingly aggressive treatment in 75- to 84-year-old females did not differ from their counterparts in the younger cohort. CONCLUSION: Screening for lung cancer might be of benefit to individuals at increased risk of lung cancer in the 75-84 age group. The survival benefits of aggressive therapy are similar in females between 55-74 and 75-84 years old.

Circulating interleukin-8 levels explain breast cancer osteolysis in mice and humans.

Skeletal metastases of breast cancer and subsequent osteolysis connote a dramatic change in the prognosis for the patient and significantly increase the morbidity associated with disease. The cytokine interleukin 8 (IL-8/CXCL8) is able to directly stimulate osteoclastogenesis and bone resorption in mouse models of breast cancer bone metastasis. In this study, we determined whether circulating levels of IL-8 were associated with increased bone resorption and breast cancer bone metastasis in patients and investigated IL-8 action in vitro and in vivo in mice. Using breast cancer patient plasma (36 patients), we identified significantly elevated IL-8 levels in bone metastasis patients compared with patients lacking bone metastasis (p<0.05), as well as a correlation between plasma IL-8 and increased bone resorption (p<0.05), as measured by NTx levels. In a total of 22 ER+ and 15 ER- primary invasive ductal carcinomas, all cases examined stained positive for IL-8 expression. In vitro, human MDA-MB-231 and MDA-MET breast cancer cell lines secrete two distinct IL-8 isoforms, both of which were found to stimulate osteoclastogenesis. However, the more osteolytic MDA-MET-derived full length IL-8(1-77) had significantly higher potency than the non-osteolytic MDA-MB-231-derived IL-8(6-77), via the CXCR1 receptor. MDA-MET breast cancer cells were injected into the tibia of nude mice and 7days later treated daily with a neutralizing IL-8 monoclonal antibody. All tumor-injected mice receiving no antibody developed large osteolytic bone tumors, whereas 83% of the IL-8 antibody-treated mice had no evidence of tumor at the end of 28days and had significantly increased survival. The pro-osteoclastogenic activity of IL-8 in vivo was confirmed when transgenic mice expressing human IL-8 were examined and found to have a profound osteopenic phenotype, with elevated bone resorption and inherently low bone mass. Collectively, these data suggest that IL-8 plays an important role in breast cancer osteolysis and that anti-IL-8 therapy may be useful in the treatment of the skeletal related events associated with breast cancer.

Identification of PTHrP(12-48) as a plasma biomarker associated with breast cancer bone metastasis.

BACKGROUND: Breast cancer bone metastasis is a complication that significantly compromises patient survival due, in part, to the lack of disease-specific biomarkers that allow early and accurate diagnosis. METHODS: Using mass spectrometry protein profiling, plasma samples were screened from three independent breast cancer patient cohorts with and without clinical evidence of bone metastasis. RESULTS: The results identified 13 biomarkers that classified all 110 patients with a sensitivity of 91% and specificity of 93% [receiver operating characteristics area under the curve (AUC = 1.00)]. The most discriminatory protein was subsequently identified as a unique 12-48aa peptide fragment of parathyroid hormone-related protein (PTHrP). PTHrP(12-48) was significantly increased in plasma of patients with bone metastasis compared with patients without bone metastasis (P < 0.0001). Logistic regression models were used to evaluate the diagnostic potential of PTHrP(12-48) as a single biomarker or in combination with the measurement of the clinical marker N-telopeptide of type I collagen (NTx). The PTHrP(12-48) and NTx logistic regression models were not significantly different and classified the patient groups with high accuracy (AUC = 0.85 and 0.95), respectively. Interestingly, in combination with serum NTx, the plasma concentration of PTHrP(12-48) increased diagnostic specificity and accuracy (AUC = 0.99). CONCLUSIONS: These data show that PTHrP(12-48) circulates in plasma of patient with breast cancer and is a novel and predictive biomarker of breast cancer bone metastasis. Importantly, the clinical measurement of PTHrP(12-48) in combination with NTx improves the detection of breast cancer bone metastasis. IMPACT: In summary, we present the first validated, plasma biomarker signature for diagnosis of breast cancer bone metastasis that may improve the early diagnosis of high-risk individuals.

Elevation in inflammatory serum biomarkers predicts response to trastuzumab-containing therapy.

Approximately half of all HER2/neu-overexpressing breast cancer patients do not respond to trastuzumab-containing therapy. Therefore, there remains an urgent and unmet clinical need for the development of predictive biomarkers for trastuzumab response. Recently, several lines of evidence have demonstrated that the inflammatory tumor microenvironment is a major contributor to therapy resistance in breast cancer. In order to explore the predictive value of inflammation in breast cancer patients, we measured the inflammatory biomarkers serum ferritin and C-reactive protein (CRP) in 66 patients immediately before undergoing trastuzumab-containing therapy and evaluated their progression-free and overall survival. The elevation in pre-treatment serum ferritin (>250 ng/ml) or CRP (>7.25 mg/l) was a significant predictor of reduced progression-free survival and shorter overall survival. When patients were stratified based on their serum ferritin and CRP levels, patients with elevation in both inflammatory biomarkers had a markedly poorer response to trastuzumab-containing therapy. Therefore, the elevation in inflammatory serum biomarkers may reflect a pathological state that decreases the clinical efficacy of this therapy. Anti-inflammatory drugs and life-style changes to decrease inflammation in cancer patients should be explored as possible strategies to sensitize patients to anti-cancer therapeutics.

Elevated bone turnover predicts for bone metastasis in postmenopausal breast cancer: results of NCIC CTG MA.14.

PURPOSE: We investigated the association of bone-only relapse with a pretreatment marker of bone resorption: serum beta C-terminal telopeptide (B-CTx) of type I collagen. METHODS: Pretreatment serum B-CTx concentrations were determined from 621 of 667 patients with primary breast cancer enrolled onto the NCIC CTG MA.14 phase III adjuvant trial of tamoxifen with or without octreotide. Recurrence-free survival (RFS) was a secondary end point; the focus here was bone-only relapse. We analyzed continuous or categorical (.71 ng/mL cut point) serum B-CTx in stepwise forward multivariate Cox regression, adjusted for trial stratification factors. We also examined B-CTx and bone relapse by pretrial chemotherapy status. RESULTS: At median 7.9 years follow-up, 123 of 621 patients experienced recurrence; 19 (3.1%) of 621 had bone-only recurrence, and 47 (7.5%) of 621 had bone plus other sites of recurrence. Larger pathologic tumor size (P = .001) and elevated continuous and categorical serum B-CTx were associated with shorter bone-only RFS (both P = .02) when added to a model with factors significant in the main trial analyses (hazard ratio [HR], 3.43 and 3.50, respectively; 95% CI, 1.20 to 9.77 and 1.26 to 9.75, respectively). The univariate HR for B-CTx was 2.80 (95% CI, 1.05 to 7.48; P = .03). Elevated serum B-CTx was also associated with shorter bone-only RFS (P = .02) when added to a model with factors significant in the main trial analyses. Serum B-CTx level was not associated with any other type of recurrence. Serum B-CTx was not significantly different for patients who underwent pretrial chemotherapy, compared with those who did not (P = .27), nor did pretrial chemotherapy affect bone relapse (P = .48 for bone only; P = .76 for bone with other relapse). CONCLUSION: Higher pretreatment serum B-CTx was a significant predictor of shorter RFS for bone-only metastasis. Increased bone resorption creates an environment that promotes growth of breast cancer cells.

Human epidermal growth factor receptor 2 (HER2) extracellular domain levels are associated with progression-free survival in patients with HER2-positive metastatic breast cancer receiving lapatinib monotherapy.

BACKGROUND: Changes in serum human epidermal growth factor receptor 2 (HER2) levels associated with clinical outcomes, including objective response rate, progression-free survival (PFS), and overall survival have been reported in patients with metastatic breast cancer (MBC) receiving trastuzumab and chemotherapy. This study investigated whether baseline or changes in serum HER2 correlated with overall response rate (ORR) and/or PFS in patients with MBC receiving first-line lapatinib monotherapy. METHODS: The EGF20009 study investigated lapatinib monotherapy in 138 HER2-positive patients with MBC previously untreated for their metastatic disease. Serum was collected and assessed at baseline and every 4 weeks for 16 weeks after treatment initiation. Disease assessment was performed at weeks 8 and 12 and every 12 weeks thereafter. A ≥ 20% decrease or increase in serum HER2 was defined as a significant change. RESULTS: Seventy-nine percent of patients had elevated baseline serum HER2. Baseline serum HER2 was associated with ORR (P = .043) but not PFS. Patients with a ≥ 20% decrease from baseline of serum HER2 at weeks 4, 8, 12, and 16 had a significantly increased ORR and prolonged PFS. Conversely, those with a ≥ 20% increase from baseline had a significantly lower ORR and shorter PFS. CONCLUSION: Significant decreases in serum HER2 levels during the first 16 weeks of lapatinib monotherapy were associated with better clinical outcome (longer PFS and increased ORR) in HER2-positive MBC patients.

Elevated plasma tissue inhibitor of metalloproteinase-1 levels predict decreased survival in castration-resistant prostate cancer patients.

BACKGROUND: Tissue inhibitor of metalloproteinase-1 (TIMP-1) has paradoxical multifunctional roles in tumorigenesis: inhibition of the catalytic activity of matrix metalloproteinases and apoptosis as well as promotion of angiogenesis and tumor growth. Elevated TIMP-1 levels have been associated with a poorer prognosis in multiple cancers. METHODS: Ethylenediaminetetraacetic acid plasma TIMP-1 was determined in 362 castration-resistant prostate cancer (PC) patients using a TIMP-1 enzyme-linked immunosorbent assay. All patients with castration-resistant PC and available plasma were identified from an institutional database. Overall survival was analyzed using the Kaplan-Meier method and Cox modeling on plasma TIMP-1 tertiles. RESULTS: Patients were evaluated in pilot (n = 60) and primary (n = 302) sets. Median follow-up from diagnosis was 5.8 and 6.6 years, respectively. Median plasma TIMP-1 levels were 335 and 183 ng/mL in the pilot and primary sets, respectively. Overall survival was significantly shorter with each higher tertile of TIMP-1 in both datasets (P<.001). For the primary cohort, hazard ratio of (HR) death and median survival by plasma TIMP-1 tertile levels were: low, HR 1.0, 43 months; middle, HR 1.7, 27 months; high, HR 2.4, 19 months. In the primary set, significant covariates in the adjusted Cox regression model were: TIMP-1 level (mid or high vs low tertile), prostate-specific antigen (>20 vs ≤20 ng/mL), alkaline phosphatase (>102 vs ≤102 U/L), Eastern Cooperative Oncology Group performance status (1 + vs 0), and Gleason score (7 or 8 vs ≤6). CONCLUSIONS: Elevated plasma TIMP-1 levels predicted decreased survival in metastatic castration-resistant PC patients, independent of known prognostic markers.

Quantitation of p95HER2 in paraffin sections by using a p95-specific antibody and correlation with outcome in a cohort of trastuzumab-treated breast cancer patients.

PURPOSE: p95HER2 is an NH(2)-terminally truncated form of HER2 that lacks the trastuzumab binding site and is therefore thought to confer resistance to trastuzumab treatment. In this report, we introduce a new antibody that has enabled the first direct quantitative measurement of p95HER2 in formalin-fixed paraffin-embedded (FFPE) breast cancer tissues. We sought to show that quantitative p95HER2 levels would correlate with outcome in trastuzumab-treated HER2-positive metastatic breast cancer. EXPERIMENTAL DESIGN: The novel p95HER2 antibody used here was characterized for sensitivity, specificity, and selectivity over full-length HER2. Quantitative p95HER2 levels were measured in 93 metastatic breast tumors using a VeraTag FFPE assay to determine the correlation of p95HER2 levels with outcomes. RESULTS: Within a cohort of trastuzumab-treated metastatic breast cancer patients, high levels of p95HER2 were found to correlate with shorter progression-free survival [hazard ratio (HR), 1.9; P = 0.017] and overall survival (HR, 2.2; P = 0.012) in patients with tumors selected to be HER2 positive by the VeraTag HER2 assay. For those with tumors found to be fluorescence in situ hybridization positive, elevated p95HER2 correlated similarly with shorter progression-free survival (HR, 1.8; P = 0.022) and overall survival (HR, 2.2; P = 0.009). CONCLUSIONS: We have successfully generated an antibody that can specifically detect p95HER2, and developed an assay to quantify expression in FFPE tumor specimens. Using this novel assay, we have identified a group of HER2-positive patients expressing p95HER2 that have a worse outcome while on trastuzumab. As p95HER2 retains sensitivity to kinase inhibitors, measurement of p95HER2 in breast tumor sections may be useful in guiding treatment for patients with HER2-positive breast cancer.

Quantitative HER2 protein levels predict outcome in fluorescence in situ hybridization-positive patients with metastatic breast cancer treated with trastuzumab.

BACKGROUND: Only a portion of breast cancer patients currently selected for trastuzumab therapy respond. METHODS: Using a novel assay (HERmark) to quantify total human epidermal growth factor receptor 2 (HER2) expression, the authors examined outcomes in 102 trastuzumab-treated metastatic breast cancer patients previously assessed as immunohistochemistry (IHC) 3+ by local but not central IHC, or fluorescence in situ hybridization (FISH) positive, and then retested by central FISH. RESULTS: Of 102 MBC patients previously scored as IHC 3+ or 2+/FISH-positive and treated with trastuzumab-containing regimens, 98 had both central FISH and HER2 total expression values. Sixty-six of 76 central FISH-positive patients (87%) had high HER2 total expression levels (concordant positive), and 19 of 22 central FISH-negative patients (86%) were HER2 total expression low (concordant negative). Fourteen percent (3 of 22) of central FISH-negative patients were HER2 total expression high (discordant HER2 total expression high), and 13% (10 of 76) of central FISH-positive patients were HER2 total expression low (discordant HER2 total expression low). The concordant positive group had a significantly longer time to progression (TTP, median = 11.3 months) compared with the concordant negative group (median TTP, 4.5 months; hazard ratio [HR] = 0.42, P < .001), and also compared with the discordant HER2 total expression low group (median TTP, 3.7 months; HR = 0.43, P = .01). The discordant HER2 total expression low group behaved similarly compared with concordant negatives (HR = 1, P = .99). In analyses restricted to central FISH-positive patients only (n = 77), Cox proportional hazards multivariate regression identified HER2 total expression as an independent predictor of TTP (HR = 0.29, P = .0015) and overall survival (HR = 0.19, P < .001). CONCLUSIONS: A subset of patients with HER2 gene amplification by FISH express low levels of HER2 protein and have reduced response to trastuzumab-containing therapy, similar to FISH-negative patients. This cohort represents a training dataset, and the observed relationships and derived cutoffs require validation in an independent cohort of trastuzumab-treated metastatic breast cancer patients.

Serum HER-2/neu and relative resistance to trastuzumab-based therapy in patients with metastatic breast cancer.

BACKGROUND: Previous reports based on small patient numbers suggested that changes in serum HER-2/neu levels may predict response or lack of response to trastuzumab-based therapies in metastatic breast cancer (MBC). The objectives of this study were to pool data from 307 patients with MBC from 7 medical institutions to validate that the serum HER-2/neu profile predicts patient resistance to trastuzumab and to establish a clinically relevant cutoff. METHODS: This was an international, multicenter, retrospective analysis of individual pooled data from 307 patients with MBC who were treated with first-line trastuzumab-based therapy. Serum was collected at baseline and 30 to 120 days after the initiation of trastuzumab therapy. A serum HER-2/neu decrease >or=20% (receiver operating curve analysis) was defined as a significant HER-2/neu change. RESULTS: Of the 307 patients with MBC, 191 patients (62%) had a significant decline (>20%) in serum HER-2/neu and 116 patients (38%) did not. The objective response rate was 57% for patients who achieved this decline in serum HER-2/neu (>20%) compared with 28% for patients who did not. Patients who achieved this decline in serum HER-2/neu also had a significantly longer time to disease progression (320 days vs 180 days; P < .0001), longer duration of response (369 days vs 230 days; P = .008), and longer overall survival (898 days vs 593 days; P < .018). CONCLUSIONS: In this pooled analysis of 307 patients with MBC, individuals who did not achieve a significant decline (>or=20%) in serum HER-2/neu levels had decreased benefit from trastuzumab-based therapy, and these patients should be considered for clinical trials evaluating additional HER-2/neu-targeted interventions.

Serum TIMP-1 and response to the aromatase inhibitor letrozole versus tamoxifen in metastatic breast cancer.

PURPOSE: To determine the effect of elevated serum TIMP-1 on the response of patients with metastatic breast cancer to an aromatase inhibitor versus tamoxifen. PATIENTS AND METHODS: Five hundred twenty-two patients estrogen receptor-positive metastatic breast cancer were randomly assigned to receive first-line hormone therapy with letrozole or tamoxifen. Serum tissue inhibitor of metalloproteinases-1 (TIMP-1) levels were measured using an enzyme-linked immunosorbent assay. RESULTS: Pretreatment serum TIMP-1 was elevated in 120 (23%) of 522 patients. Patients with elevated serum TIMP-1 had a significantly reduced objective response rate (19.2% v 30.6%; odds ratio, 0.54; P = .01), duration of response (median, 15.5 v 26.2 months; P = .001), time to treatment progression (TTP; median, 4.5 v 9.2 months; HR, 1.78; P = .0001), time to treatment failure (median, 3.5 v 9.0 months; HR, 1.77; P = .0001), and overall survival (median, 20.3 v 35.8 months; HR, 1.77; P = .0001) compared with patients with normal pretreatment TIMP-1 levels. Letrozole was superior to tamoxifen in both the normal serum TIMP-1 group (median TTP, 11.8 v 8.6 months; P = .003) and in the elevated serum TIMP-1 group (median, 6.1 v 3.2 months; P = .03) In multivariate analysis, elevated serum TIMP-1 remained an independent predictor of both shorter TTP (HR, 1.46; P = .002) and survival (HR, 1.44; P = .002), as did serum HER-2. Combined analysis of both serum TIMP-1 and HER-2/neu conferred additional ability to predict significantly different clinical outcomes compared to using either biomarker alone. CONCLUSION: Patients with elevated pretreatment serum TIMP-1 had a significantly reduced response and survival. Serum TIMP-1 was an independent predictive and prognostic factor. Blockade of TIMP-1 and HER-2/neu activity may be beneficial in a subset of patients with breast cancer.

Elevated plasma tissue inhibitor of metalloproteinase-1 level predicts decreased response and survival in metastatic breast cancer.

BACKGROUND: Tissue inhibitors of metalloproteinase (TIMPs) have at least 2 different functions. They inhibit the catalytic activity of matrix metalloproteinases, and they act as growth factors. METHODS: Pretreatment ethylenediamine tetracetic acid plasma TIMP-1 was assayed from 251 patients who were enrolled in a Phase III, second-line, hormone therapy trial, and from a control group of 50 healthy, postmenopausal women by using the TIMP-1 enzyme-linked immunosorbent assay. RESULTS: The plasma TIMP-1 levels from the postmenopausal control group (n = 50 women) were 201 +/- 86 ng/mL mean +/- standard deviation (range, 49-455 ng/mL). The upper limit of normal was defined as the mean +/- 2 standard deviations of the control group (373 ng/mL). Patient pretreatment plasma TIMP-1 levels ranged from 70 ng/mL to 982 ng/mL. Plasma TIMP-1 was elevated above the mean + 2 standard deviations of the control group (373 ng/mL) in 19 patients (7.6%). In univariate analysis, patients who had elevated versus normal plasma TIMP-1 levels had a reduced clinical benefit rate (CBR) (16% vs 42%; P = .03). The time to progression (TTP) (84 days vs 174 days; P < .0001) and overall survival (141 days vs 860 days; P = .0001) also were significantly shorter in patients who had elevated TIMP-1 levels. TTP and overall survival also were significantly shorter in patients who had higher TIMP-1 plasma levels when it was analyzed as a continuous variable. In multivariate analysis, elevated plasma TIMP-1 level remained a prognostic factor for reduced overall survival (P < .0001) along with elevated serum HER-2/neu (P < .0001) and the presence of visceral metastases (P = .008). CONCLUSIONS: Elevated pretreatment plasma levels of TIMP-1 predicted a decreased response to second-line hormone therapy and reduced survival in women with metastatic breast cancer.