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Condition (MeSH)

Breast Neoplasms

ClinicalTrials.gov lists 14,335 trials for Breast Neoplasms or a narrower condition beneath it. National Cancer Institute (NCI) has the most among industry and government lead sponsors, with 308.

MeSH D001943 Neoplasms Neoplasm C04 C17
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Phase 1 Phase 1 1,627 Phase 1/2 Phase 1/2 764 Phase 2 Phase 2 3,088 Phase 2/3 Phase 2/3 126 Phase 3 Phase 3 1,216 Phase 4 Phase 4 284 Not applicable Not applicable 4,101 Observational Observational 3,103 Phase 1 Phase 1 1,627 Phase 1/2 Phase 1/2 764 Phase 2 Phase 2 3,088 Phase 2/3 Phase 2/3 126 Phase 3 Phase 3 1,216 Phase 4 Phase 4 284 Not applicable Not applicable 4,101 Observational Observational 3,103

Trials per phase (log scale)

2 more sections with rows

13,456 of the 14,335 trials are tagged with Breast Neoplasms 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 Neoplasms 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: 847

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: 145 trials (Observational 20, Not applicable 14, Phase 4 4, Phase 3 33, Phase 2 44, Phase 1/2 9, Phase 1 21) 2002: 172 trials (Observational 15, Not applicable 19, Phase 4 4, Phase 3 37, Phase 2/3 3, Phase 2 70, 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: 304 trials (Observational 59, Not applicable 41, Phase 4 11, Phase 3 39, Phase 2/3 4, Phase 2 101, Phase 1/2 13, Phase 1 36) 2006: 390 trials (Other 2, Observational 71, Not applicable 77, Phase 4 11, Phase 3 53, Phase 2/3 5, Phase 2 111, Phase 1/2 18, Phase 1 42) 2007: 421 trials (Observational 90, Not applicable 69, Phase 4 13, Phase 3 40, Phase 2/3 1, Phase 2 131, Phase 1/2 26, Phase 1 51) 2008: 459 trials (Observational 107, Not applicable 75, Phase 4 11, Phase 3 50, Phase 2/3 3, Phase 2 130, Phase 1/2 28, Phase 1 55) 2009: 447 trials (Observational 102, Not applicable 82, Phase 4 6, Phase 3 47, Phase 2/3 4, Phase 2 117, Phase 1/2 32, Phase 1 57) 2010: 451 trials (Other 1, Observational 123, Not applicable 90, Phase 4 10, Phase 3 32, Phase 2/3 4, Phase 2 109, Phase 1/2 25, Phase 1 57) 2011: 431 trials (Other 1, Observational 113, Not applicable 88, Phase 4 10, Phase 3 31, Phase 2/3 7, Phase 2 112, Phase 1/2 11, Phase 1 58) 2012: 440 trials (Observational 108, Not applicable 114, Phase 4 7, Phase 3 36, Phase 2/3 11, Phase 2 98, Phase 1/2 15, Phase 1 51) 2013: 452 trials (Observational 90, Not applicable 130, Phase 4 12, Phase 3 39, Phase 2/3 5, Phase 2 107, Phase 1/2 11, Phase 1 58) 2014: 510 trials (Observational 112, Not applicable 148, Phase 4 12, Phase 3 42, Phase 2/3 8, Phase 2 99, Phase 1/2 25, Phase 1 64) 2015: 600 trials (Observational 113, Not applicable 214, Phase 4 8, Phase 3 40, Phase 2/3 2, Phase 2 123, Phase 1/2 36, Phase 1 64) 2016: 608 trials (Observational 111, Not applicable 212, Phase 4 18, Phase 3 39, Phase 2/3 4, Phase 2 109, Phase 1/2 32, Phase 1 83) 2017: 618 trials (Other 1, Observational 117, Not applicable 205, Phase 4 7, Phase 3 37, Phase 2/3 8, Phase 2 122, Phase 1/2 40, Phase 1 81) 2018: 608 trials (Observational 130, Not applicable 213, Phase 4 11, Phase 3 37, Phase 2/3 10, Phase 2 90, Phase 1/2 34, Phase 1 83) 2019: 703 trials (Observational 172, Not applicable 229, Phase 4 11, Phase 3 35, Phase 2/3 2, Phase 2 123, Phase 1/2 44, Phase 1 87) 2020: 668 trials (Observational 140, Not applicable 212, Phase 4 11, Phase 3 34, Phase 2/3 5, Phase 2 134, Phase 1/2 36, Phase 1 96) 2021: 794 trials (Observational 198, Not applicable 283, Phase 4 17, Phase 3 47, Phase 2/3 7, Phase 2 131, Phase 1/2 36, Phase 1 75) 2022: 813 trials (Observational 208, Not applicable 278, Phase 4 18, Phase 3 49, Phase 2/3 8, Phase 2 123, Phase 1/2 47, Phase 1 82) 2023: 811 trials (Observational 199, Not applicable 280, Phase 4 12, Phase 3 46, Phase 2/3 7, Phase 2 131, Phase 1/2 52, Phase 1 84) 2024: 835 trials (Observational 204, Not applicable 298, Phase 4 18, Phase 3 44, Phase 2/3 3, Phase 2 145, Phase 1/2 39, Phase 1 84) 2025: 847 trials (Observational 207, Not applicable 300, Phase 4 13, 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) 759
2025 847
2024 835
2023 811
2022 813
2021 794
2020 668
2019 703
2018 608
2017 618

Forecast of the full-year count, planned starts included, not rows of this table: about 950 trials starting in 2026 and about 850 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 1,654 trials still running at the 2026-10-09 snapshot; registered median of 34 months across 8,331 trials with a primary completion typed Actual. Source: ClinicalTrials.gov / AACT (CTTI), public domain.

What phase are Breast Neoplasms trials in? (10)

Shown in this order: phase order.

Show the trials by phase as a table
Trials by phase
Phase Trials
Phase 1 1,627
Phase 1/2 764
Phase 2 3,088
Phase 2/3 126
Phase 3 1,216
Phase 4 284
Not applicable 4,101
Observational 3,103
Expanded access 24
Unknown 2

How many Breast Neoplasms 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 659
Recruiting 2,039
Enrolling by invitation 79
Active, not recruiting 989
Available 6

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

Which lead sponsors run the most Breast Neoplasms 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
Hoffmann-La Roche 183
AstraZeneca 182
Novartis Pharmaceuticals 181
Pfizer 159

Which drugs are being tested for Breast Neoplasms? (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 239

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 Neoplasms 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 Neoplasms? (13,723)

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

Publications
Publication Journal Year Major topic
Scaffold-based breast conserving surgery in patients with non-malignant breast lesions: long-term follow-up of a first-in-human pilot study on the REGENERA™ biomimetic breast implant. Breast cancer (Tokyo, Japan) 2026 Yes
Platelet-Rich Plasma Treatment for Endocrine-Induced Alopecia and Persistent Chemotherapy-Induced Alopecia in Breast Cancer Survivors: A Randomized, Controlled, Pilot Study. Dermatologic surgery : official publication for American Society for Dermatologic Surgery [et al.] 2026 Yes
The impact of multimodal high intensity exercise program comparing online and onsite interventions in breast cancer survivors: a randomized controlled trial. Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico 2026 Yes
Incorporating sentinel chain involvement pattern to predict non-sentinel lymph nodes status in breast cancer after neoadjuvant chemotherapy. Clinical & translational oncology : official publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico 2026 Yes
Late Toxicities and Quality of Life After a Radiation Boost for Breast Ductal Carcinoma In Situ: Boost or No Boost in DCIS Randomized Trial. International journal of radiation oncology, biology, physics 2026 Yes

Sub-conditions in MeSH (8)

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