Please assess the completion status of the following clinical trial:

Trial Title: Comparative Real World Tumor Response in Pre-menopausal Metastatic Breast Cancer Patients Treated With Palbociclib + Aromatase Inhibitor or Aromatase Inhibitor Alone

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: COHORT
- Primary Purpose: None
- Time Perspective: RETROSPECTIVE
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~1. Pre or perimenopausal at MBC diagnosis~2. Diagnosis of MBC in patient history~3. Confirmed HR+/HER2- status as defined as: a. HR+: ER+ or PR+ test; b. HER2-: any HER2 negative test and the absence of a positive test (IHC positive 3+, fluorescence in situ hybridization \[FISH\] positive/amplified, positive not otherwise specified \[NOS\]).~4. Received one of the following regimens as first-line treatment for MBC during the period from 01 January 2010 through index period 30 June 2020 until the data cutoff date of 31 December 2020.~   1. Palbociclib + AI as first-line treatment for MBC or~  2. Monotherapy AI as first-line treatment for MBC~5. Received care at a US Oncology Network (USON) site(s) utilizing the full EHR capacities of iKnowMed (iKM) at the time of treatment.~6. EHR data available from the USON site(s) where the patient received treatment are accessible for research purposes.~Exclusion Criteria:~1. Evidence of prior treatment with cyclin-dependent kinase (CDK) 4/6 inhibitors (palbociclib, ribociclib or abemaciclib) in the early breast cancer (BC) or MBC setting.~2. First structured activity (clinical visit) greater than 120 days after MBC diagnostic date with chart review to confirm no initial MBC treatment outside USON.~3. Receipt of treatment indicated for another primary cancer during the study observation period (after initiation of Palbociclib + AI or AI monotherapy and before 31 December 2020) or history of another primary cancer within USON.~4. Enrolled in any interventional clinical trial after initiation of Palbociclib + AI or AI monotherapy AND before 31 December 2020.

- Gender: FEMALE
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Palbociclib + aromatase inhibitor (Type: None): Palbociclib + aromatase inhibitor
- Aromatase inhibitor alone (Type: None): Aromatase inhibitor alone

Based on this trial design, predict the completion outcome and termination type (if applicable).