Study to omit irradiation after partial mastectomy with hormone therapy

Study to omit irradiation after partial mastectomy with hormone therapy - Breast conserving surgery without irradiation

Status

Active, not recruiting

Phases

Phase 2

Study type

Interventional

Source

JPRN

Registry ID

JPRN-UMIN000041364

Enrollment

300

Registered

2020-08-10

Start date

2015-10-01

Completion date

Unknown

Last updated

2026-06-29

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Breast cancer

Interventions

Omission of breast irradiation Breast irradiation

Eligibility

Sex/Gender

Female

Inclusion criteria

Inclusion criteria: 1) Case where partial mastectomy was performed 2) Non-invasive breast cancer or invasive cancer with an invasion diameter of 2 cm or less at the final pathological diagnosis 3) Cases where consent was obtained by informed consent

Exclusion criteria

Exclusion criteria: 1) Patients who received drug therapy before surgery 2) Cases that the doctor has determined to be inappropriate

Design outcomes

Primary

Measure	Time frame
Proportion of 5-year local recurrence free breasts	—

Secondary

Measure	Time frame
1) Local recurrence rate 2)Distant organ recurrence-free survival rate 3) Regional lymph node recurrence-free survival rate 4) Pathological study of local recurrence 5) Contralateral breast cancer incidence	—

Countries

Japan

Contacts

Public ContactMasujiro Makita

Nippon Medical School Musashikosugi Hospital Department of breast surgery

m-makita@nms.ac.jp0447335181

Outcome results

None listed

Source: JPRN (via WHO ICTRP) · Data processed: Jul 3, 2026