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Condition (MeSH)

Breast Diseases

ClinicalTrials.gov lists 14,470 trials for Breast Diseases or a narrower condition beneath it. National Cancer Institute (NCI) has the most among industry and government lead sponsors, with 308.

MeSH D001941 Skin and Connective Tissue Diseases C17
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Phase 1 Phase 1 1,628 Phase 1/2 Phase 1/2 767 Phase 2 Phase 2 3,094 Phase 2/3 Phase 2/3 129 Phase 3 Phase 3 1,223 Phase 4 Phase 4 294 Not applicable Not applicable 4,163 Observational Observational 3,146 Phase 1 Phase 1 1,628 Phase 1/2 Phase 1/2 767 Phase 2 Phase 2 3,094 Phase 2/3 Phase 2/3 129 Phase 3 Phase 3 1,223 Phase 4 Phase 4 294 Not applicable Not applicable 4,163 Observational Observational 3,146

Trials per phase (log scale)

2 more sections with rows

146 of the 14,470 trials are tagged with Breast Diseases itself; the rest are tagged with a narrower condition beneath it.

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The PDF carries up to 50 rows of each section, where the page shows the first few, with the sources listed. Enter a work email and confirm it from the message we send, and the report follows by email.

When did Breast Diseases trials start? (37)

Shown in this order: most recent first, 1990 onwards. 2026 is partial: trials registered with a 2026 start date so far, not a full year. 27 trials are registered to start in 2027 or later, and not listed here.

Trials over time, by phase

  • Phase 1
  • Phase 1/2
  • Phase 2
  • Phase 2/3
  • Phase 3
  • Phase 4
  • Not applicable
  • Observational
  • Other (Expanded access, Unknown)

Top of scale: 853

1990: 8 trials (Observational 4, Not applicable 1, Phase 4 1, Phase 3 2) 1991: 10 trials (Observational 2, Not applicable 1, Phase 3 2, Phase 2 2, Phase 1/2 1, Phase 1 2) 1992: 5 trials (Observational 1, Not applicable 1, Phase 3 1, Phase 2 1, Phase 1 1) 1993: 12 trials (Not applicable 1, Phase 3 11) 1994: 19 trials (Observational 3, Not applicable 1, Phase 3 4, Phase 2 5, Phase 1/2 2, Phase 1 4) 1995: 22 trials (Observational 5, Not applicable 1, Phase 3 9, Phase 2 3, Phase 1/2 1, Phase 1 3) 1996: 47 trials (Observational 11, Not applicable 1, Phase 3 18, Phase 2 7, Phase 1/2 2, Phase 1 8) 1997: 57 trials (Observational 7, Not applicable 6, Phase 4 1, Phase 3 12, Phase 2/3 1, Phase 2 18, Phase 1/2 5, Phase 1 7) 1998: 79 trials (Observational 12, Not applicable 7, Phase 3 22, Phase 2 27, Phase 1/2 5, Phase 1 6) 1999: 82 trials (Observational 9, Not applicable 4, Phase 4 1, Phase 3 23, Phase 2 24, Phase 1/2 4, Phase 1 17) 2000: 124 trials (Observational 20, Not applicable 15, Phase 4 1, Phase 3 19, Phase 2/3 2, Phase 2 45, Phase 1/2 11, Phase 1 11) 2001: 146 trials (Observational 20, Not applicable 14, Phase 4 4, Phase 3 34, Phase 2 44, Phase 1/2 9, Phase 1 21) 2002: 176 trials (Observational 16, Not applicable 20, Phase 4 4, Phase 3 37, Phase 2/3 3, Phase 2 72, Phase 1/2 7, Phase 1 17) 2003: 206 trials (Observational 32, Not applicable 31, Phase 4 7, Phase 3 33, Phase 2/3 1, Phase 2 75, Phase 1/2 7, Phase 1 20) 2004: 265 trials (Observational 33, Not applicable 43, Phase 4 3, Phase 3 47, Phase 2/3 1, Phase 2 99, Phase 1/2 15, Phase 1 24) 2005: 307 trials (Observational 59, Not applicable 42, Phase 4 11, Phase 3 40, Phase 2/3 4, Phase 2 102, Phase 1/2 13, Phase 1 36) 2006: 393 trials (Other 2, Observational 73, Not applicable 77, Phase 4 11, Phase 3 54, Phase 2/3 5, Phase 2 111, Phase 1/2 18, Phase 1 42) 2007: 422 trials (Observational 90, Not applicable 69, Phase 4 13, Phase 3 40, Phase 2/3 1, Phase 2 132, Phase 1/2 26, Phase 1 51) 2008: 462 trials (Observational 107, Not applicable 76, Phase 4 12, Phase 3 50, Phase 2/3 4, Phase 2 130, Phase 1/2 28, Phase 1 55) 2009: 450 trials (Observational 102, Not applicable 83, Phase 4 6, Phase 3 48, Phase 2/3 5, Phase 2 117, Phase 1/2 32, Phase 1 57) 2010: 453 trials (Other 1, Observational 123, Not applicable 91, Phase 4 10, Phase 3 32, Phase 2/3 4, Phase 2 110, Phase 1/2 25, Phase 1 57) 2011: 437 trials (Other 1, Observational 115, Not applicable 91, Phase 4 10, Phase 3 31, Phase 2/3 7, Phase 2 112, Phase 1/2 12, Phase 1 58) 2012: 446 trials (Observational 110, Not applicable 118, Phase 4 7, Phase 3 36, Phase 2/3 11, Phase 2 98, Phase 1/2 15, Phase 1 51) 2013: 455 trials (Observational 90, Not applicable 133, Phase 4 12, Phase 3 39, Phase 2/3 5, Phase 2 107, Phase 1/2 11, Phase 1 58) 2014: 512 trials (Observational 113, Not applicable 148, Phase 4 12, Phase 3 43, Phase 2/3 8, Phase 2 99, Phase 1/2 25, Phase 1 64) 2015: 604 trials (Observational 116, Not applicable 215, Phase 4 8, Phase 3 40, Phase 2/3 2, Phase 2 123, Phase 1/2 36, Phase 1 64) 2016: 616 trials (Observational 114, Not applicable 215, Phase 4 19, Phase 3 39, Phase 2/3 4, Phase 2 109, Phase 1/2 32, Phase 1 84) 2017: 623 trials (Other 1, Observational 117, Not applicable 208, Phase 4 9, Phase 3 37, Phase 2/3 8, Phase 2 122, Phase 1/2 40, Phase 1 81) 2018: 616 trials (Observational 132, Not applicable 217, Phase 4 12, Phase 3 37, Phase 2/3 10, Phase 2 91, Phase 1/2 34, Phase 1 83) 2019: 716 trials (Observational 174, Not applicable 237, Phase 4 12, Phase 3 36, Phase 2/3 3, Phase 2 123, Phase 1/2 44, Phase 1 87) 2020: 680 trials (Observational 145, Not applicable 217, Phase 4 12, Phase 3 35, Phase 2/3 5, Phase 2 134, Phase 1/2 36, Phase 1 96) 2021: 808 trials (Observational 206, Not applicable 288, Phase 4 18, Phase 3 47, Phase 2/3 7, Phase 2 131, Phase 1/2 36, Phase 1 75) 2022: 819 trials (Observational 211, Not applicable 281, Phase 4 18, Phase 3 49, Phase 2/3 8, Phase 2 123, Phase 1/2 47, Phase 1 82) 2023: 815 trials (Observational 200, Not applicable 283, Phase 4 12, Phase 3 46, Phase 2/3 7, Phase 2 131, Phase 1/2 52, Phase 1 84) 2024: 844 trials (Observational 208, Not applicable 303, Phase 4 18, Phase 3 44, Phase 2/3 3, Phase 2 145, Phase 1/2 39, Phase 1 84) 2025: 853 trials (Observational 208, Not applicable 304, Phase 4 14, Phase 3 65, Phase 2/3 5, Phase 2 146, Phase 1/2 43, Phase 1 68)

Trials registered with a start date in each year, 1990 onward, stacked by phase (complete years only; the current partial year is in the table's notes). The table below lists the same counts, most recent years first.

Trials started per year
Year Trials started
2026 (partial year) 768
2025 853
2024 844
2023 815
2022 819
2021 808
2020 680
2019 716
2018 616
2017 623

Forecast of the full-year count, planned starts included, not rows of this table: about 960 trials starting in 2026 and about 860 in 2027, the average of the 24 months through September, counted as registered and carried forward, with about 0.7 times the starts already registered for the rest of 2026 added. The rows of this table count trials registered so far with a start date in the year, planned starts included; the forecast looks ahead to the count for the whole year, so it is not the same measure. In backtests on conditions of this size, forecasts made part-way through the year were typically off by about 10 percent and ran about 4 percent high against the count later registered; forecasts made before the year began were off by about 25 percent and ran about 15 percent low against the count later registered, and had about 7 percent more error than repeating last year's count. The part-way figures are from forecasts that used a multiple fitted only on earlier years. A stricter check that trains only on older years did not support adding planned starts for conditions of this size: it ran about 6 percent high against the count later registered. These figures rest on a few years of history (target years from 2018 to 2025, varying by figure), place each condition as it is mapped today rather than as it was then, and score against a count for the newest year that was still being revised. Only condition series were scored.

Prediction, not a registry value: median of 36 months from start to primary completion across 1,662 trials still running at the 2026-10-09 snapshot; registered median of 34 months across 8,414 trials with a primary completion typed Actual. Source: ClinicalTrials.gov / AACT (CTTI), public domain.

What phase are Breast Diseases trials in? (10)

Shown in this order: phase order.

Show the trials by phase as a table
Trials by phase
Phase Trials
Phase 1 1,628
Phase 1/2 767
Phase 2 3,094
Phase 2/3 129
Phase 3 1,223
Phase 4 294
Not applicable 4,163
Observational 3,146
Expanded access 24
Unknown 2

How many Breast Diseases trials are recruiting? (13)

Shown in this order: the order a trial moves through, from not yet recruiting to unknown.

Trials by recruitment status
Status Trials
Not yet recruiting 665
Recruiting 2,052
Enrolling by invitation 81
Active, not recruiting 993
Available 6

Status as registered on ClinicalTrials.gov. Each trial is counted once.

Which lead sponsors run the most Breast Diseases trials? (6)

Shown in this order: most trials first. Lead sponsors the registry classes as industry, NIH, US federal, other government or network. A hospital or university the registry files as government can appear here. Sponsors it classes as academic or other are shown on the full page, because that class cannot separate an institution from a named investigator.

Lead sponsors
Sponsor Trials
National Cancer Institute (NCI) 308
AstraZeneca 185
Hoffmann-La Roche 183
Novartis Pharmaceuticals 181
Pfizer 159

Which drugs are being tested for Breast Diseases? (8)

Shown in this order: most trials first. One row per drug, matched to a single molecule under all its names, ranked by number of trials.

Drugs tested
Drug Trials
(nab)-paclitaxel 553
TRASTUZUMAB 546
Cytoxan 500
"Capecitabine" 338
FULVESTRANT 283

Interventions as named in the registry (7)

Shown in this order: most trials first.

Interventions as named in the registry
Drug Trials
Docetetaxel 383
Letrozol (Femara, Novartis) 301
or carboplatin 287
Doxorubicine 279
Tamoxifen Pill 241

These are the names sponsors entered on ClinicalTrials.gov that we have not matched to a single molecule. Some are drugs under a brand or code name; others are procedures, doses or arm labels.

Which serious adverse events do Breast Diseases trials report? (10)

Shown in this order: most subjects affected first. Subjects affected summed across trials, a cross-trial signal, not a rate.

Serious adverse events in this condition's trials
Adverse event Subjects affected Trials
Febrile neutropenia 3,539 400
Neutropenia 2,670 295
Breast cancer 2,488 60
Pneumonia 2,315 418
Vomiting 2,201 533

Which publications cover Breast Diseases? (197)

Shown in this order: major-topic papers first, then newest, then most linked to trials.

Sub-conditions in MeSH (6)

MeSH descendants one level down with at least one trial, most trials first.

Not on this page

Not measured: delivery record.

Checked, with nothing recorded for this condition: prevalence and rare-disease identity.

Browse all condition evidence pages