Humidified Forest Oils for Immune System Recovery in Stage I-III Breast or Prostate Cancer

March 5, 2026 updated by: Amy M. Ross Ph.D., OHSU Knight Cancer Institute

Feasibility of Substitution of Volatile Organic Compound Humidification to Simulate the Forest Experience Effects on Immune System Recovery

This clinical trial studies the feasibility of simulating forest therapy using humidified wood or fragrant oils, in improving immune cells, like natural killer cells, number and activity, and their downstream proteins, perforin and granulysin in patients with stage I-III breast or prostate cancer who completed chemo- and/or radiation therapy. The knowledge gained from this study may help cancer patients who have compromised immune systems and who also cannot participate in outdoor activities like exercise or forest walks.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

PRIMARY OBJECTIVE:

I. Determine the feasibility of using humidified phytoncides to simulate the forest greenspace immersion (simulated forest immersion therapy [SFIT]) in cancer patients with solid tumor who have completed surgery, chemo- and radiation therapy as an alternate method of access to the natural forest greenspace.

SECONDARY OBJECTIVE:

I. Determine the feasibility of collecting and analyzing immune system measures while deploying the simulated forest immersion therapy with forest oils (SFIT), as well as measuring natural killer (NK) cell number and activity, and perforin and granulysin.

OUTLINE:

Patients participate in SFIT, using humidified wood and fragrance oils, over 1 hour on day 1, day 3 or 4 and on day 7. Patients also undergo blood sample collection at baseline and on days 3 or 4 and 7 and participate in interviews at baseline and post-treatment.

Study Type

Interventional

Enrollment (Actual)

28

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Oregon
      • Portland, Oregon, United States, 97239
        • OHSU Knight Cancer Institute

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age >= 18 years. Both men and women and members of all races and ethnic groups will be included
  • Participants must have histologically or cytologically confirmed breast cancer or prostate cancer (hormone therapy excepted) who are in stage I-V with or without evidence of metastasis using the Cancer Therapy Evaluation Program (CTEP) Simplified Disease Classification
  • Participants must be within 12 months of their first diagnosis of breast or prostate cancer
  • Criteria for solid tumors: Participants must have measurable disease, per doctor of medicine (MD) and data in medical record
  • Participants must have no history of autoimmune disease
  • Ability to understand and the willingness to sign a written informed consent document

Exclusion Criteria:

  • If they have asthma. Rationale: forest oils may be a possible trigger for asthma
  • If they have a known allergy to citrus peel or pine forests. Rationale: forest oils may cause contact dermatitis and coughing
  • If they are unable to detect common odors from commercial fragrances. Rationale, forest oils are humidified as an aroma to be inhaled in the simulate the forest greenspace immersion (SFIT)
  • First diagnosis of breast or prostate cancer is longer than 12 months ago. Rationale, NK cell number recovery may be complete by this time after first treatment
  • Febrile illness/infection within previous two weeks. Rationale, immune biomarkers will reflect previous febrile illness
  • Current tobacco or tobacco use within 1 hour of start of SFIT. Rationale: forest oils may cause contact dermatitis and coughing
  • Prior autoimmune disease, are on immune-modulating therapies (endocrine therapy allowed). Rationale, because of their poor prognosis rather than being in early stages of cancer
  • Had surgery or invasive procedure in the past two months. Rationale, because of their poor prognosis rather than being in early stages of cancer
  • Inability to complete study requisites

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Supportive care (SFIT, biospecimen, interview)
Patients participate in SFIT, using humidified wood and fragrance oils, over 1 hour. on day 1, day 3 or 4 and on day 7. Patients also undergo blood sample collection at baseline and on days 3 or 4 and 7 and participate in interviews at baseline and post-treatment.
Other: Aromatherapy with Essential Oils
Participate in SFIT this is one intervention with aroma therapy with essential Forest oils
Other Names:
  • Therapy
  • Therapeutic Interventions
  • Therapeutic Method
  • Therapeutic Technique
  • Therapeutic Procedure

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Humidified phytoncides to simulate the forest greenspace immersion (SFIT)
Time Frame: Baseline/Day 1
Feasibility analysis will include qualitative interview data blinded by participant, CRC/research assistant and principal investigator. Qualitative interview questions include ease of use/deployment of humidified forest oils by the CRC/research assistant and PI, the ability of the participants to tolerate SFIT. The responses will be coded, themed and summarized will be used to determine the feasibility of intervention deployment and creation of a standardized procedure for future research. To determine dose drop off between the start of SFIT and the end of SFIT of the humidified phytoncides a t-test with an alpha level of 0.05 will be used.
Baseline/Day 1

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Collecting and analyzing immune system measures while deploying the simulated forest immersion therapy with forest oils
Time Frame: Baseline and at day 3 or 4 and on Day 7
Will measure natural killer (NK) cell number and activity, and perforin and granulysin. NK cell number (NK CD3-/CD56+/) and activity (NK CD3-/CD56+/CD69+) will be tested with Flow Cytology. Perforin and granulysin will be tested by ELISA. Will use a t-test to determine the differences between these 4 variables collected at baseline and a Day 3-4. An alpha level of 0.05 will be set. Alternate analysis, the change NK cell number and activity will be determined from the mean of the standard range.
Baseline and at day 3 or 4 and on Day 7

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

OHSU Knight Cancer Institute

Collaborators

Oregon Health and Science University

Investigators

  • Principal Investigator: Amy M Ross, Ph.D., OHSU Knight Cancer Institute

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

July 19, 2022

Primary Completion (Actual)

February 28, 2025

Study Completion (Actual)

March 31, 2025

Study Registration Dates

First Submitted

August 6, 2021

First Submitted That Met QC Criteria

August 12, 2021

First Posted (Actual)

August 19, 2021

Study Record Updates

Last Update Posted (Actual)

March 9, 2026

Last Update Submitted That Met QC Criteria

March 5, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

  • STUDY00023183 (Other Identifier: OHSU Knight Cancer Institute)
  • NCI-2021-08489 (Registry Identifier: CTRP (Clinical Trial Reporting Program))

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

UNDECIDED

IPD Plan Description

Undecided

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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