Breast Cancer FemaleTAMNCT06660030
Factors Influencing Tamoxifen Adherence in Women With Breast Cancer Receiving Tamoxifen in Botswana.
An observational study of Breast Cancer Female, run by University of Pennsylvania at 1 site in Botswana.
Trial summary
Botswana is an ideal location to investigate tamoxifen adherence for numerous reasons. First, in contrast to many other countries in SSA, tamoxifen is affordable and widely available to women with ER+ breast cancer in Botswana. Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Breast Cancer Female
- How many people
- 10 participants
- Where
- 1 siteBotswana
- Study dates
- 1 Mar 2024to 20 Nov 2025
- How long will I take part?
- 12 Months
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Study population: Patients will include females with ER+ breast cancer who are >18 years of age. The study population will include both women living with and without HIV. Patients offered questionnaires and blood draws will only include women treated as outpatients and be of sufficient mental capacity to personally consent to the study.
Who may be able to join
- All women over the age of 18, taking (or have taken) tamoxifen for treatment of ER+ breast cancer and being HIV positive
- All women over the age of 18, taking (or have taken) tamoxifen for treatment of ER+ breast cancer and being HIV negative
Who cannot join
- Males
- Women with ER negative breast cancer
- Women under 18 years of age at time of study administration.
Trial locations and contacts
1 site in 1 country.
About this study
Botswana is an ideal location to investigate tamoxifen adherence for numerous reasons. First, in contrast to many other countries in SSA, tamoxifen is affordable and widely available to women with ER+ breast cancer in Botswana. There is also a sufficiently high prevalence of WLW HIV and breast cancer in Botswana to provide adequate power for the proposed study. Lastly, there is a well-developed medical and scientific infrastructure, both from the clinical and laboratory perspective, to allow for successful completion of this proposed study
Read the detailed description
Breast cancer (BC) is the second-most common cancer in women in sub-Saharan Africa (SSA) (Black 2019, Trimble 2017). Tamoxifen forms a cornerstone for treatment of ER+ breast cancer and daily use after initial medical, surgical, and/or radiation therapy decreases the annual odds of recurrence and death by 39% and 31% respectively (EBCTCG 2005). Despite the proven benefits of tamoxifen, non-adherence is common. Previous reports have indicated that 31-50% of women do not adhere to prescribed treatment regimens (Lash 2006, Lambert 2018, Peddie 2021). The reasons for non-adherence are broad and not fully understood but are thought to be influenced by numerous factors including medication side-effects, beliefs about cancer, and social support framework (Clancy 2020). Data is extremely limited concerning the adherence rates to tamoxifen therapy in Africa.
The metabolism of tamoxifen is complex. It is metabolized to its effector/active metabolites via the cytochrome P450 (CYP) enzyme system, principally CYP2D6 with CYP2B6 playing a lesser, but important role (Nthontho Keneuoe Cecilia 2022). The CYP2D6 gene is highly variable but four principal drug metabolizer phenotypes have been identified: poor, intermediate, extensive, and ultra-rapid metabolizers (Nthontho KC 2022). Reduced speed of tamoxifen metabolism in poor metabolizers has been associated with higher risk of treatment failure, due to increased drug level in vivo and subsequent increased tamoxifen related side effects (Nardin 2020). However, to date, these various phenotypes have not been evaluated in an African population, so it is unclear to what extent these phenotypes effect tamoxifen adherence in SSA.
A unique aspect among the breast cancer population in Botswana is that a large portion of these women are also living with HIV. Studies have shown that the prevalence of HIV in the general population is up to 17.6% (Bhatia 2019). Little is known how antiretroviral medications effect tamoxifen adherence. One particular Anti Retroviral Therapy (ART) medication, efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor and potent CYP-inducer is used by a large portion of WLW HIV in SSA (Maseng 2022). EFV has been shown in vitro to increase estrogen expression both by inducing growth in ER-positive breast cancer cells lines (Sikora 2010) and clinically due to the development of gynecomastia seen in male patients (Osman 2020). It remains unclear, however, if and to what extent the combined administration of tamoxifen and efavirenz contributes to reduced tamoxifen adherence.
- Conditions
- Breast Cancer Female
- Being tested
- No intervention
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
No interventionOther
No intervention
What is being measured
The primary outcome is the main question the study is designed to answer.
Primary outcome
Reduced tamoxifen adherence, measured as reduced intake of pills number will be seen in women with reduced quality of EORTC QLQ( Cancer core quality of life questionnare acronym Q-C30 life scores, increased medication side effects, and/or increased barriers to medical care.
Women living with (WLW) HIV taking tamoxifen will be less adherent to tamoxifen therapy due to the higher likelihood of medication side effects
Measured: 12 months
Secondary outcomes (1)
Secondary outcome
Women identified as poor metabolizers will have higher tamoxifen and metabolite plasma concentrations (measured as mg/ml).
Measured: 12 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted26 Oct 2024
- Study start1 Mar 2024
- Primary completion20 Nov 2025
- Study completion20 Nov 2025
Why it stopped: Lack of funds
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Breast Cancer FemaleStudies of the same condition, open and under way.
- More trials run by University of PennsylvaniaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 10 participants (actual)
- Target duration
- 12 Months
Sponsor and investigators
- Lead sponsor
- University of Pennsylvania
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06660030
- Sponsor's protocol ID
- 855696
- Acronym
- TAM
- Status last verified
- Dec 2025
- First submitted
- 24 Oct 2024
- Last updated
- 10 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 10 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Factors Influencing Tamoxifen Adherence in Women With Breast Cancer Receiving Tamoxifen in Botswana.
- ClinicalTrials.gov ID
- NCT06660030
- Acronym / sponsor ID
- TAM / 855696
- Conditions
- Breast Cancer Female
- Study type
- Observational
- Recruitment status
- TerminatedReason stopped: Lack of funds
- Enrolment
- 10 participants (actual)
- Lead sponsor
- University of PennsylvaniaUniversity, hospital or other
- Study start
- 1 Mar 2024 (actual)
- Primary completion
- 20 Nov 2025 (actual)
- Study completion
- 20 Nov 2025 (actual)
- First posted
- 26 Oct 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Botswana is an ideal location to investigate tamoxifen adherence for numerous reasons. First, in contrast to many other countries in SSA, tamoxifen is affordable and widely available to women with ER+ breast cancer in Botswana. There is also a sufficiently high prevalence of WLW HIV and breast cancer in Botswana to provide adequate power for the proposed study. Lastly, there is a well-developed medical and scientific infrastructure, both from the clinical and laboratory perspective, to allow for successful completion of this proposed study
Detailed description
Breast cancer (BC) is the second-most common cancer in women in sub-Saharan Africa (SSA) (Black 2019, Trimble 2017). Tamoxifen forms a cornerstone for treatment of ER+ breast cancer and daily use after initial medical, surgical, and/or radiation therapy decreases the annual odds of recurrence and death by 39% and 31% respectively (EBCTCG 2005). Despite the proven benefits of tamoxifen, non-adherence is common. Previous reports have indicated that 31-50% of women do not adhere to prescribed treatment regimens (Lash 2006, Lambert 2018, Peddie 2021). The reasons for non-adherence are broad and not fully understood but are thought to be influenced by numerous factors including medication side-effects, beliefs about cancer, and social support framework (Clancy 2020). Data is extremely limited concerning the adherence rates to tamoxifen therapy in Africa.
The metabolism of tamoxifen is complex. It is metabolized to its effector/active metabolites via the cytochrome P450 (CYP) enzyme system, principally CYP2D6 with CYP2B6 playing a lesser, but important role (Nthontho Keneuoe Cecilia 2022). The CYP2D6 gene is highly variable but four principal drug metabolizer phenotypes have been identified: poor, intermediate, extensive, and ultra-rapid metabolizers (Nthontho KC 2022). Reduced speed of tamoxifen metabolism in poor metabolizers has been associated with higher risk of treatment failure, due to increased drug level in vivo and subsequent increased tamoxifen related side effects (Nardin 2020). However, to date, these various phenotypes have not been evaluated in an African population, so it is unclear to what extent these phenotypes effect tamoxifen adherence in SSA.
A unique aspect among the breast cancer population in Botswana is that a large portion of these women are also living with HIV. Studies have shown that the prevalence of HIV in the general population is up to 17.6% (Bhatia 2019). Little is known how antiretroviral medications effect tamoxifen adherence. One particular Anti Retroviral Therapy (ART) medication, efavirenz (EFV), a non-nucleoside reverse transcriptase inhibitor and potent CYP-inducer is used by a large portion of WLW HIV in SSA (Maseng 2022). EFV has been shown in vitro to increase estrogen expression both by inducing growth in ER-positive breast cancer cells lines (Sikora 2010) and clinically due to the development of gynecomastia seen in male patients (Osman 2020). It remains unclear, however, if and to what extent the combined administration of tamoxifen and efavirenz contributes to reduced tamoxifen adherence.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 12 Months
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Patients will include females with ER+ breast cancer who are >18 years of age. The study population will include both women living with and without HIV. Patients offered questionnaires and blood draws will only include women treated as outpatients and be of sufficient mental capacity to personally consent to the study.
Key inclusion criteria (2 listed)
- All women over the age of 18, taking (or have taken) tamoxifen for treatment of ER+ breast cancer and being HIV positive
- All women over the age of 18, taking (or have taken) tamoxifen for treatment of ER+ breast cancer and being HIV negative
Key exclusion criteria (3 listed)
- Males
- Women with ER negative breast cancer
- Women under 18 years of age at time of study administration.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| No interventionNo intervention | Other | – |
Primary outcome
Primary outcome
Time frame: 12 months
Reduced tamoxifen adherence, measured as reduced intake of pills number will be seen in women with reduced quality of EORTC QLQ( Cancer core quality of life questionnare acronym Q-C30 life scores, increased medication side effects, and/or increased barriers to medical care. Women living with (WLW) HIV taking tamoxifen will be less adherent to tamoxifen therapy due to the higher likelihood of medication side effects
1 secondary outcome
Secondary outcome
Time frame: 12 months
Results and safety
The study was stopped early (reason given: Lack of funds). Results are not available in the source record.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Dec 2025.
Related trials for Breast Cancer Female
Recruiting
Decision Support for Chemoprevention
Breast Cancer
Not yet recruiting
Geriatric Oncology Assessment and Coping Skills Training for Older Women on Aromatase Inhibitor Therapy
Breast Cancer, Hormone Receptor Positive, Aromatase Inhibitor-Associated Arthralgia
Recruiting
The Vanguard Study: Testing a New Way to Screen for Cancer
Bladder Carcinoma, Breast Carcinoma
Active, not recruitingPhase 1
A Phase 1 Study of XL309 (ISM3091) Alone and in Combination in Participants With Advanced Solid Tumors
Advanced Solid Tumor
RecruitingPhase 1
A Phase I Study of CG-7321 Monotherapy or Combination Therapy in Advanced Solid Tumors
Advanced Solid Tumors, Breast Cancer
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Breast Cancer Female, run by University of Pennsylvania at 1 site in Botswana.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: stopped early, as of the sponsor's last update on 10 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Botswana. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study was stopped early (reason given: Lack of funds). Results are not available in the source record.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Primary outcome (time frame: 12 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Dec 2025.