Reported Reactions

Reactions

MedDRA preferred term

Breast cancer metastatic: adverse event reports recording this term

10,570 reports to FDA record it, 2004–2026; 0.1% of the database.

10,570
reports recording the term
0.1% of all reports
618
reports, 12 months to June 2026
590 in the 12 months before
97.7%
marked serious by the reporter
57.4% across all reports
26.6%
record death among outcomes, as reported
9.1% across all reports

10,570 reports in FDA's adverse event database record the MedDRA term "Breast cancer metastatic": 0.1% of all reports received between January 2004 and June 2026. Coders pick the term that best matches the reporter's description.

618 reports recorded it in the 12 months to June 2026, close to the 590 of the 12 months before. FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases. Of reports recording this term, 97.7% are marked serious, 26.6% include death among the outcomes and 20.3% include hospitalisation, as reported.

The drugs listed most often as suspect products in those reports are Premarin, Prempro and Letrozole. That order mostly follows how many reports each drug has overall; the table also gives the term's share within each drug's own reports. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

Reports by month, five years

053106Jul 2021: 82Aug 2021: 74Sep 2021: 97Oct 2021: 60Nov 2021: 65Dec 2021: 682022Jan 2022: 32Feb 2022: 60Mar 2022: 70Apr 2022: 67May 2022: 50Jun 2022: 52Jul 2022: 60Aug 2022: 58Sep 2022: 44Oct 2022: 50Nov 2022: 53Dec 2022: 622023Jan 2023: 36Feb 2023: 49Mar 2023: 69Apr 2023: 41May 2023: 62Jun 2023: 96Jul 2023: 73Aug 2023: 71Sep 2023: 76Oct 2023: 106Nov 2023: 62Dec 2023: 372024Jan 2024: 46Feb 2024: 37Mar 2024: 35Apr 2024: 45May 2024: 33Jun 2024: 27Jul 2024: 28Aug 2024: 46Sep 2024: 52Oct 2024: 33Nov 2024: 45Dec 2024: 612025Jan 2025: 51Feb 2025: 46Mar 2025: 54Apr 2025: 56May 2025: 53Jun 2025: 65Jul 2025: 44Aug 2025: 58Sep 2025: 68Oct 2025: 50Nov 2025: 49Dec 2025: 492026Jan 2026: 42Feb 2026: 59Mar 2026: 62Apr 2026: 48May 2026: 49Jun 2026: 40

FDA releases FAERS data quarterly, so the newest months are incomplete and grow in later releases.

Drugs listed as suspect products in these reports

DrugClassReports with this termShare of the drug's own reports
PremarinEstrogen1,5674.6%
PremproEstrogen1,4997.6%
LetrozoleAromatase inhibitor1,4175.1%
ProveraProgestin1,2115.9%
KisqaliKinase inhibitor1,1634.7%
FulvestrantEstrogen receptor antagonist1,0558.9%
CapecitabineNucleoside metabolic inhibitor6821.3%
IbranceKinase inhibitor5310.6%
TrastuzumabHER2/neu receptor antagonist5191.8%
ExemestaneAromatase inhibitor4766.8%
PaclitaxelMicrotubule inhibitor4500.6%
AfinitorKinase inhibitor4491.5%
RibociclibKinase inhibitor4377%
Medroxyprogesterone acetateProgestin4285%
Tamoxifen—4095.2%
HerceptinHER2/neu receptor antagonist4041.3%
PalbociclibKinase inhibitor3593.6%
XgevaRANK ligand inhibitor3561.6%
CyclophosphamideAlkylating drug3280.2%
XelodaNucleoside metabolic inhibitor3211%
AnastrozoleAromatase inhibitor3153.1%
Zometa—3101.3%
DocetaxelMicrotubule inhibitor3050.5%
FaslodexEstrogen receptor antagonist2663%
CarboplatinPlatinum-based drug2620.3%

Drugs with a page on this site, ordered by the number of their reports recording this term. The last column is the term's share within that drug's own reports, against 0.1% across the whole database. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

By pharmacologic class

ClassReports with this termShare of class reportsMedian drug in class
Kinase inhibitor3,7240.4%0%
Estrogen3,5532.8%0.1%
Aromatase inhibitor2,6883.8%3%
Progestin1,7660.6%0%
Nucleoside metabolic inhibitor1,3530.4%0%
Estrogen receptor antagonist1,3264.8%3%
HER2/neu receptor antagonist1,2531.5%1.2%
Microtubule inhibitor9990.7%0.6%
RANK ligand inhibitor5400.3%1.4%
Alkylating drug3330.1%0%

Classes ordered by count. Class shares follow the class's overall report volume as much as anything else.

Patients in these reports

Patient age

Under 20%0
2 to 110%0
12 to 170%0
18 to 446.7%709
45 to 6425%2,643
65 to 7410.6%1,122
75 and over5.5%578
Age not given52.2%5,518

Patient sex

Female92.3%9,760
Male0.7%76
Not given6.9%734

Grey bar: all 20,646,523 reports in the database. 47.1% of these reports give the United States as the country.

Questions about "Breast cancer metastatic"

What does "Breast cancer metastatic" mean in an adverse event report?

It is a MedDRA preferred term, the dictionary FDA uses to code what a reporter described. The report's own description is not published by openFDA and is not shown here.

How many reports record breast cancer metastatic?

10,570 reports through June 2026 (0.1% of all reports), 618 of them in the latest 12 months.

Which drugs appear most often in these reports?

Premarin (1,567), Prempro (1,499), Letrozole (1,417), Provera (1,211) and Kisqali (1,163). Drugs with many reports overall lead almost every term's list. FDA states that adverse event reports "represent a small percentage of total usage numbers of a product", that "common products may have a higher number of adverse events due to the higher total number of people using the product", and that the data "by themselves are not an indicator of the safety profile of the drug or biologic."

Does a drug appearing here mean it was responsible for this reaction?

No. FDA states that "a causal relationship cannot be established between product and reactions listed in a report" and that for any given report "there is no certainty that a suspected drug caused the event."

I have this symptom. What should I do?

This site cannot assess anyone. A pharmacist or clinician can; for an emergency, call the local emergency number. Nothing on this page is medical advice.

Where this comes from. Counts are built from the openFDA Drug Adverse Event (FAERS) bulk export released 28 Sep 2026, which holds reports FDA received through 30 Jun 2026. Drug names are as reported, resolved to the brand or generic name on the FDA label where openFDA's harmonisation matched them; classes are the pharmacologic class (EPC) from the label and the National Drug Code Directory of 17 Sep 2026. Terms are pooled across spelling and capitalisation variants of one MedDRA preferred term. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.

Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.