The impact of cancer metastases on COVID-19 outcomes: A COVID-19 and Cancer Consortium registry-based retrospective cohort study

BACKGROUND

COVID-19 can have a particularly detrimental effect on patients with cancer, but no studies to date have examined if the presence, or site, of metastatic cancer is related to COVID-19 outcomes.

METHODS

Using the COVID-19 and Cancer Consortium (CCC19) registry, the authors identified 10,065 patients with COVID-19 and cancer (2325 with and 7740 without metastasis at the time of COVID-19 diagnosis). The primary ordinal outcome was COVID-19 severity: not hospitalized, hospitalized but did not receive supplemental O2 , hospitalized and received supplemental O2 , admitted to an intensive care unit, received mechanical ventilation, or died from any cause. The authors used ordinal logistic regression models to compare COVID-19 severity by presence and specific site of metastatic cancer. They used logistic regression models to assess 30-day all-cause mortality.

RESULTS

Compared to patients without metastasis, patients with metastases have increased hospitalization rates (59% vs. 49%) and higher 30 day mortality (18% vs. 9%). Patients with metastasis to bone, lung, liver, lymph nodes, and brain have significantly higher COVID-19 severity (adjusted odds ratios [ORs], 1.38, 1.59, 1.38, 1.00, and 2.21) compared to patients without metastases at those sites. Patients with metastasis to the lung have significantly higher odds of 30-day mortality (adjusted OR, 1.53; 95% confidence interval, 1.17-2.00) when adjusting for COVID-19 severity.

CONCLUSIONS

Patients with metastatic cancer, especially with metastasis to the brain, are more likely to have severe outcomes after COVID-19 whereas patients with metastasis to the lung, compared to patients with cancer metastasis to other sites, have the highest 30-day mortality after COVID-19.

Systemic Anticancer Therapy and Thromboembolic Outcomes in Hospitalized Patients With Cancer and COVID-19

Importance

Systematic data on the association between anticancer therapies and thromboembolic events (TEEs) in patients with COVID-19 are lacking.

Objective

To assess the association between anticancer therapy exposure within 3 months prior to COVID-19 and TEEs following COVID-19 diagnosis in patients with cancer.

Design, Setting, and Participants

This registry-based retrospective cohort study included patients who were hospitalized and had active cancer and laboratory-confirmed SARS-CoV-2 infection. Data were accrued from March 2020 to December 2021 and analyzed from December 2021 to October 2022.

Exposure

Treatments of interest (TOIs) (endocrine therapy, vascular endothelial growth factor inhibitors/tyrosine kinase inhibitors [VEGFis/TKIs], immunomodulators [IMiDs], immune checkpoint inhibitors [ICIs], chemotherapy) vs reference (no systemic therapy) in 3 months prior to COVID-19.

Main Outcomes and Measures

Main outcomes were (1) venous thromboembolism (VTE) and (2) arterial thromboembolism (ATE). Secondary outcome was severity of COVID-19 (rates of intensive care unit admission, mechanical ventilation, 30-day all-cause mortality following TEEs in TOI vs reference group) at 30-day follow-up.

Results

Of 4988 hospitalized patients with cancer (median [IQR] age, 69 [59-78] years; 2608 [52%] male), 1869 had received 1 or more TOIs. Incidence of VTE was higher in all TOI groups: endocrine therapy, 7%; VEGFis/TKIs, 10%; IMiDs, 8%; ICIs, 12%; and chemotherapy, 10%, compared with patients not receiving systemic therapies (6%). In multivariable log-binomial regression analyses, relative risk of VTE (adjusted risk ratio [aRR], 1.33; 95% CI, 1.04-1.69) but not ATE (aRR, 0.81; 95% CI, 0.56-1.16) was significantly higher in those exposed to all TOIs pooled together vs those with no exposure. Among individual drugs, ICIs were significantly associated with VTE (aRR, 1.45; 95% CI, 1.01-2.07). Also noted were significant associations between VTE and active and progressing cancer (aRR, 1.43; 95% CI, 1.01-2.03), history of VTE (aRR, 3.10; 95% CI, 2.38-4.04), and high-risk site of cancer (aRR, 1.42; 95% CI, 1.14-1.75). Black patients had a higher risk of TEEs (aRR, 1.24; 95% CI, 1.03-1.50) than White patients. Patients with TEEs had high intensive care unit admission (46%) and mechanical ventilation (31%) rates. Relative risk of death in patients with TEEs was higher in those exposed to TOIs vs not (aRR, 1.12; 95% CI, 0.91-1.38) and was significantly associated with poor performance status (aRR, 1.77; 95% CI, 1.30-2.40) and active/progressing cancer (aRR, 1.55; 95% CI, 1.13-2.13).

Conclusions and Relevance

In this cohort study, relative risk of developing VTE was high among patients receiving TOIs and varied by the type of therapy, underlying risk factors, and demographics, such as race and ethnicity. These findings highlight the need for close monitoring and perhaps personalized thromboprophylaxis to prevent morbidity and mortality associated with COVID-19-related thromboembolism in patients with cancer.

Interplay of Immunosuppression and Immunotherapy Among Patients With Cancer and COVID-19

Importance

Cytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.

Objective

To determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.

Design, Setting, and Participants

This registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.

Exposures

Immunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).

Main Outcomes and Measures

The primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.

Results

The median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).

Conclusions and Relevance

This cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.

Trial Registration

ClinicalTrials.gov Identifier: NCT04354701.

Patients recently treated for B-lymphoid malignancies show increased risk of severe COVID-19: a CCC19 registry analysis

Patients with B-lymphoid malignancies have been consistently identified as a population at high risk of severe COVID-19. Whether this is exclusively due to cancer-related deficits in humoral and cellular immunity, or whether risk of severe COVID-19 is increased by anti-cancer therapy, is uncertain. Using data derived from the COVID-19 and Cancer Consortium (CCC19), we show that patients treated for B-lymphoid malignancies have an increased risk of severe COVID-19 compared to control populations of patients with non-B-lymphoid hematologic malignancies. Among patients with B-lymphoid malignancies, those who received anti-cancer therapy within 12 months of COVID-19 diagnosis experienced increased COVID-19 severity compared to patients with B-lymphoid malignancies off therapy, after adjustment for cancer status and several other prognostic factors. Our findings suggest that patients recently treated for a B-lymphoid malignancy are at uniquely high risk for severe COVID-19.

Abstract P5-13-10: Elevated plasma IL-8 predicts for reduced outcomes in CCTG MA.38, a phase 2 randomized trial of palbociclib in ER+/HER2- metastatic breast cancer patients

Background: CCTG MA38 (NCT02630693) was a randomized phase II clinical trial that evaluated the efficacy of 2 dose schedules of palbociclib [100mg PO on continuous daily dose (CDD)] compared to 125mg PO daily for 3 weeks on/1 week off (STD) along with physician-choice of endocrine therapy in patients with ER+, HER- metastatic breast cancer (MBC) in the second-line setting. The final analysis indicated that palbociclib had comparable efficacy, safety and QOL for both treatment arms (SABCS 2018, abstr PD1-10). Our lab has reported that IL-8 was highly expressed by primary human breast cancers, and that higher pretreatment plasma IL-8 was significantly correlated with elevated bone resorption in HR+MBC patients (Kamalakar A et al. Bone 61:176-85, 2014). Most recently, our lab has reported that elevated serum IL-8 predicts for significantly reduced OS in 3 large metastatic cohorts of pancreatic (ASCO 2019, abstr 4131), prostate (ASCO 2020, abstr e17565) and breast cancer patients (ASCO 2020, abstr 1067). In this retrospective study, we investigated the prognostic value of pretreatment plasma IL-8 in CCTG MA38. Methods: 123 patients enrolled in MA38 were analyzed in this retrospective biomarker study. Serum IL-8 levels were measured using the ELLA immunoassay platform (ProteinSimple, San Jose, CA). Kaplan-Meier analysis and log-rank test were used to correlate plasma IL-8 levels with OS and progression-free survival (PFS). Results: In the total study cohort, pretreatment plasma IL-8 concentration had a median of 11.10 pg/ml, and 25% and 75% interquartiles of 7.36 and 15.00 pg/ml, respectively. In univariate analysis higher plasma IL-8 was a significant adverse biomarker for reduced PFS as a continuous variable (p = 0.01), at the median cutpoint (HR= 1.55, p=0.042), and in quartile cutpoints (HR=2.28, p=0.03, Q4 vs Q1). For OS, higher plasma IL-8 also trended significant for reduced OS at the median cutpoint (HR= 1.66, p=0.10). In multivariate analysis, higher plasma IL-8 also trended significant for reduced PFS (HR= 1.47, p=0.094). Conclusions: In the CCTG MA.38 trial, higher pre-treatment plasma IL-8 level was associated with reduced PFS, and is therefore an adverse prognostic biomarker for reduced outcome to the CDK 4/6 inhibitor palbociclib. Anti-IL-8 therapy combined with CDK 4/6 inhibitors should be evaluated in future trials to improve outcome in patients with higher circulating IL-8.

Citation Format: Hyma V Polimera, Dhirisha Bhatt, Lois E Shepherd, Karen Gelmon, Anil A Joy, Wendy R Parulekar, Monika Joshi, Suhail M Ali, Kim Leitzel, Cristina Truica, Monali Vasekar, Joseph J Drabick, Harry Menon, Neal Shah, Ashok Maddukuri, Prashanth Moku, E. Scott Halstead, Daniel McKeone, Todd M Umstead, BE Chen, Allan Lipton. Elevated plasma IL-8 predicts for reduced outcomes in CCTG MA.38, a phase 2 randomized trial of palbociclib in ER+/HER2- metastatic breast cancer patients [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr P5-13-10.

A Case of Cefepime-Induced Neurotoxicity: Renal Function Missing in Action

Cefepime is a renally excreted, fourth-generation cephalosporin used in the treatment of severe abdominal, skin, soft tissue, and urinary tract infections due to its broad-spectrum coverage. Cefepime-induced neurotoxicity is a rare but serious side effect that has increased in recent years likely due to increased antibiotic use, increased drug resistance, and increased symptom recognition. While decreased glomerular filtration rate is an important risk factor for developing elevated serum cefepime levels, recent literature has suggested that a significant proportion of patients with normal renal function can also develop neurotoxicity from cefepime. Here, we present a case of cefepime-induced neurotoxicity to demonstrate the importance of monitoring mental status changes in all patients being treated with cefepime.

Immune mediated necrotizing myopathy: A rare complication of statin therapy

Immune mediated necrotizing myopathy (IMNM) is part of the inflammatory myopathies group of diseases and presents with muscle weakness, myalgias and elevated serum creatine phosphokinase (CPK). Statin-induced IMNM is a rare complication. We present a patient with IMNM secondary to simvastatin use. The patient presented with proximal myopathy, dysphagia, and elevated creatinine kinase levels, and was subsequently found to have anti-3- hydroxy-3-methylglutaryl-CoA reductase (HMGCR) autoantibodies with a necrotizing process on muscle biopsy. This patient’s case was further complicated by sequelae of multiple disease processes, ultimately leading to deterioration of his health.

Abstract P4-10-25: Pretreatment serum metabolome predicts PFS in first-line trastuzumab-treated metastatic breast cancer

Background: Cancer cells have altered metabolism, which contributes to their ability to proliferate, survive in unusual microenvironments, and invade other tissues. Measuring the complete set of metabolites in an individual (i.e. the metabolome) provides a functional readout for cellular pathways. Further, changes in the metabolome can be correlated with disease status, prognosis and progression. Using a metabolomics platform and machine learning algorithms, biomarker signatures can be identified to predict response to therapy. Metabolite analysis of pretreatment plasma has shown promise for predicting response in a small retrospective study of the CDK 4/6 inhibitors palbociclib and ribociclib in hormone receptor-positive metastatic breast cancer (Zhang B et al, ASCO 2019 Abstr 3043). HER2-positive metastatic breast cancer patients have significant heterogeneity in response and progression-free survival (PFS) to HER2-targeted therapy. Here we retrospectively evaluated the pretreatment serum metabolome for association with PFS in a cohort of trastuzumab-treated metastatic breast cancer patients from a single institution. Methods: Pretreatment serum from 26 HER2-positive trastuzumab-naive metastatic breast cancer patients who were treated with first-line trastuzumab and chemotherapy were included in this exploratory analysis. Metabolites were extracted from previously frozen serum (1 mL) using ice-cold methanol and chloroform. The resulting metabolites were isolated and quantified using an unbiased, non-destructive, nuclear magnetic resonance (NMR)-based profiling platform (Olaris, Inc., Cambridge, MA). The serum was analyzed via 1D 1H NMR and 2D 13C-1H heteronuclear single quantum coherence spectroscopy (HSQC) using customized non-uniform sampling (NUS) techniques and processed with proprietary Olaris software. Supervised and unsupervised machine learning algorithms were used to identify patients with shorter and longer PFS to trastuzumab-based therapy. Results: The median PFS for this cohort was 301 days. Patients were subdivided into early progressors (PFS < 301 days) and late progressors (PFS ≥ 301 days). 23 metabolite resonance levels were statistically different between the two groups (KW test p<0.05, 11 metabolites expected by chance). Using advanced machine learning we constructed a model based on 5 metabolite resonances that showed significant discriminatory ability with an AUC of 0.964 using receiver-operating curve (ROC) analysis. 21 of the 26 patients received trastuzumab and chemotherapy as a first-line therapy, while the remaining 5 patients received first-line trastuzumab with subsequent chemotherapy, after 1 or more lines of previous chemotherapy for metastatic disease. We repeated our analysis using only the first-line therapy subgroup and identified a partially overlapping set of metabolite resonances that could nearly perfectly discriminate early and late progressors with an AUC of 0.973. Further efforts are underway to confirm the identity of these metabolites. Conclusions: Metabolic profiling of pretreatment serum using NMR was successful in identifying a biomarker signature that predicted PFS to trastuzumab in HER2-positive metastatic breast cancer. Expanded metabolome analysis is warranted in larger cohorts and clinical trials to confirm that this serum biomarker signature predicts PFS to trastuzumab therapy, particularly in the first-line setting. Further, by identifying the metabolites and metabolic pathways that differ between early and late progressors, it may be possible to identify novel targets and/or suggest combination treatments in the HER2-positive metastatic breast cancer setting.

Citation Format: Elizabeth O'Day, Kim Leitzel, Suhail M Ali, Bo Zhang, Chen Dong, Haiwei Gu, Xiajian Shi, Joseph J Drabick, Leah Cream, Monali Vasekar, Hyma V Polimera, Vinod Nagabhairu, Prashanth Moku, Ashok Maddukuri, Harry Menon, Neha Pancholy, Walter P Carney, Wolfgang Koestler, Allan Lipton. Pretreatment serum metabolome predicts PFS in first-line trastuzumab-treated metastatic breast cancer [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P4-10-25.

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 (>25^th percentile cut-point, HR = 2.01, 95%CI = 1.33–3.05) and higher C3M/PRO-C3 ratio was associated with improved OS (>25^th 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.

A Case of Confirmed Ceftriaxone-induced Immune Thrombocytopenia

Drug-induced immune thrombocytopenia (DITP) is a rare, but potentially fatal cause of isolated thrombocytopenia. DITP is thought to occur when drug-dependent antibodies bind to the platelet membrane glycoproteins to activate platelet consumption signaling. Common implicated drugs include quinine/quinidine, penicillamines, valproic acid and cotrimoxazole. Ceftriaxone is a rare culprit with only six reported cases since 1991, of which only three were confirmed with drug-dependent antiplatelet antibodies. We describe a case of antibody confirmed ceftriaxone-induced immune thrombocytopenia after initiation of empiric antibiotic therapy for acute bacterial meningitis.

Abstract PD3-10: Higher serum PD-L1 predicts for increased overall survival to lapatinib vs trastuzumab in the phase 3 CCTG MA.31 trial

Background: In the CCTG (Canadian Clinical Trials Group) MA.31 randomized phase 3 trial, the trastuzumab-taxane combination led to longer PFS than lapatinib-taxane in HER2-positive metastatic breast cancer (MBC). We previously reported the prognostic utility of pretreatment serum PD-L1 in the trastuzumab arm of MA.31 (ASCO 2018, #1031), and here we evaluate serum PD-L1 in the lapatinib arm, and in the whole trial. Higher serum PD-L1 has been reported to be associated with reduced response to treatment with the immune checkpoint inhibitors in melanoma and lung cancer.

Methods: MA.31 accrued 652 centrally and/or locally-identified HER2-positivepatients; 186 in the trastuzumab arm, and 202 in the lapatinib armhad pretreatment serum available. TheELLA immunoassay platform (ProteinSimple, San Jose, CA) was used to quantitate serum PD-L1. Step-wise forward Cox multivariate analysis was used for PFS and OS, and testing for treatment-biomarker interaction was based on the local partial-likelihood method (Liu Y, Jiang W, and Chen BE, Statistics in Medicine 34, 3516-3530, 2015).

Results: In the total study population, pretreatment serum PD-L1 concentration had a median of 86.2 pg/ml, and 25% and 75% interquartiles of 64.1 and 134.3 pg/ml, respectively. In univariate analysis in the whole trial, and within both treatment arms, serum PD-L1 was not a significant biomarker for PFS. For OS, higher serum PD-L1 (as a continuous variable) was significant for shorter OS within the trastuzumab arm (HR=3.84, p=0.04), but was not associated with OS in the lapatinib arm (p=0.37). In the whole trial, in multivariate analysis for OS [15 covariates included: age, race, ECOG status, anthracyclines, other chemo, endocrine, radio, other prior adjuvant therapy, disease status, ER status, PR status, Ki67 (log transformed), CK5, EGFR, treatment arm, and serum PD-L1 (with median cut point)], serum PD-L1 remained a significant independent covariate (HR= 2.27, p= 0.001 (Table).There was significant interaction between treatment arm and continuous serum PD-L1 (Bootstrap method, p=0.0025); above 214.2 pg/ml serum PD-L1 (89% percentile), higher pretreatment serum PD-L1 was associated with a shorter OS to trastuzumab treatment, but longer OS to lapatinib treatment.

Conclusions: In the CCTG MA.31 trial, serum PD-L1 was a significant predictive factor: higher pretreatment serum PD-L1 was associated with a shorter OS to trastuzumab treatment, but longer OS to lapatinib treatment. Immune evasion may decrease the effectiveness of trastuzumab therapy. Further evaluation of elevated serum PD-L1 in the advanced breast cancer setting is warranted to identify HER2-positive MBC patients who may benefit from novel immune-targeted therapies in addition to trastuzumab.

Multivariate Analysis (whole trial): Significant Independent CovariatesCovariateP-ValueHRLower 95% CIHigher 95% CISerum PD-L1 (pretreatment) (>median vs <median)0.0012.271.403.68EGFR Status (continuous IHC score)0.0031.0121.0041.019Other Chemotherapy (yes vs no)0.0081.911.193.07Treatment Arm (trastuzumab vs. lapatinib)0.0100.530.330.86ECOG Performance Status (0 vs 1 or 2)0.0250.590.370.94Ki67 (log)0.0461.451.0062.081

Citation Format: Moku PR, Shepherd LE, Ali SM, Leitzel K, Parulekar WE, Zhu L, Virk S, Nomikos D, Aparicio S, Gelmon KA, Drabick JJ, Cream L, Halstead SE, Umstead T, Mckeone D, Maddukuri A, Polimera HV, Ali A, Poulose J, Pancholy N, Spiegel H, Nagabhairu V, Chen BE, Lipton A. Higher serum PD-L1 predicts for increased overall survival to lapatinib vs trastuzumab in the phase 3 CCTG MA.31 trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD3-10.

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.