Clinical trial · Observational
Collection of Tissue Samples for Study of Multidrug Resistance
Multidrug Resistance Molecular Target Analysis of Human Samples Collected in Clinical Trials Performed Outside of the Intramural National Cancer Institute
- Source
- ClinicalTrials.gov
- Retrieved
- Sep 8, 2026
- Layer
- normalized (units and labels harmonized; values unchanged)
- Run
- ING-CLINICALTRIALS-20260908-000001
Summary
Brief summary (as posted)
Background: Resistance to cancer chemotherapy develops in patients, rendering certain treatments ineffective. Despite much research, the prevailing cause of drug resistance is not known. One mechanism for drug resistance involves a protein called P-glycoprotein, or Pgp, which reduces the effectiveness of cancer treatments by "pumping" anti-cancer drugs out of tumor cells where they are supposed to work against the disease. Objectives: To identify and evaluate more thoroughly the roles of Pgp and other substances in mediating drug resistance. Eligibility: Patients enrolled in clinical trials of cancer therapies at the Children's Hospital of Pittsburgh; Cancer Centers of Carolinas; Arizona Clinical Research Center; University of Copenhagen; and Herlev Hospital, Copenhagen who have consented to the use of blood, tissue, or tumor samples for laboratory studies. Design: Blood, tumor, and tissue samples are collected from participants and sent to the NCI for various laboratory analyses. ...
Conditions
Conditions (3)
Free-text conditions as registered, with the CancerIndex entity they were reconciled to and the match type.
| Condition (as posted) | Mapped entity | Match | Confidence |
|---|---|---|---|
| Breast Cancer | Malignant Breast Neoplasm | CURATED_EXACT | 0.92 |
| Breast Carcinoma | Breast Carcinoma | ONTOLOGY_EXACT | 0.98 |
| Medullary Thyroid Carcinoma | Thyroid Gland Medullary Carcinoma | ALIAS | 0.90 |
Interventions
Interventions (0)
Data not yet available
Design
Arms and outcomes
Arms (0)
[]Primary outcomes (1)
- measure
- Expression of MDR1/P-glycoprotein and related drug resistance proteins
- timeFrame
- Upon receipt and processing of specimen
Eligibility
Eligibility (as posted)
- Sex
- All
- Minimum age
- 18 Years
- Maximum age
- 99 Years
Show eligibility criteria text
* INCLUSION CRITERIA: Any patients entered on approved trials of cancer therapeutics at Children's Hospital of Pittsburgh, Herlev Hospital, and the University of Copenhagen outside of the intramural NCI are eligible for inclusion, provided that they have consented to tumor studies in the original consent forms. EXCLUSION CRITERIA: None anticipated at this time.
References
Publications (3)
- BACKGROUNDGottesman MM, Fojo T, Bates SE. Multidrug resistance in cancer: role of ATP-dependent transporters. Nat Rev Cancer. 2002 Jan;2(1):48-58. doi: 10.1038/nrc706. PMID 11902585
- BACKGROUNDBaer MR, George SL, Dodge RK, O'Loughlin KL, Minderman H, Caligiuri MA, Anastasi J, Powell BL, Kolitz JE, Schiffer CA, Bloomfield CD, Larson RA. Phase 3 study of the multidrug resistance modulator PSC-833 in previously untreated patients 60 years of age and older with acute myeloid leukemia: Cancer and Leukemia Group B Study 9720. Blood. 2002 Aug 15;100(4):1224-32. PMID 12149202
- BACKGROUNDRobey R, Bakke S, Stein W, Meadows B, Litman T, Patil S, Smith T, Fojo T, Bates S. Efflux of rhodamine from CD56+ cells as a surrogate marker for reversal of P-glycoprotein-mediated drug efflux by PSC 833. Blood. 1999 Jan 1;93(1):306-14. PMID 9864175