Purpose: The purpose of the study is to test a new way of measuring nerve damage in women with breast cancer receiving chemotherapy drug paclitaxel (Taxol).
Purpose: The study has four aims; * The primary aim of the study is to determine whether women who are receiving either weekly Taxol (80-100 mg/m2) or bi-weekly Taxol (i.e.,dose-dense; 175 mg/m2) show deficits in axon-reflex mediated vasodilation (AMV) over the course of six weeks of Taxol therapy similar to those that have been reported in patients with diabetic and genetically-inherited neuropathies. * The second aim of the study is to determine whether women who are receiving either weekly or dose-dense Taxol develop changes in AMV before developing signs \& symptoms of chemotherapy-induced peripheral neuropathy (CIPN) in a way that supports using changes in AMV as an early detection method for small-fiber CIPN. * A third (exploratory) aim of the study is to determine whether any changes in AMV detected during the study are significantly correlated with self-reported CIPN in a way that would support using changes in AMV as a confirmatory marker for CIPN. * A final (exploratory) aim of the study is to describe the size of axon reflexes and axon flares in women receiving weekly Taxol before they start their pre-Taxol anthracycline \& cyclophosphamide (AC) therapy.
Study Type
OBSERVATIONAL
Enrollment
29
\*Axon reflexes will be evoked in the palmar surface of the right great toe using local skin heating with a 0.33 cm2 heat probe using the following protocol: * Baseline: Heating the skin of the toe for a minimum of 5 minutes at 33\*C. * Heat Ramp: Increasing the heat in the heat probe to 42\*C at approx. 0.1\*C/10 sec. * Skin Heating: Heating the skin of the toe for 30 minutes 42\*C. * Heat Ramp: Increasing the heat in the heat probe to 44\*C at 0.1\*C/10 sec.. * Skin Heating: Heating the skin for an additional 5 minutes at 44\*C. The size of the axon reflex during this skin heating protocol will be imaged using Laser Doppler Flowmetry (LDF). In the case that participants develop CIPN on their left side only, the left toe will be substituted.
Axon flares will be generated on the palmar surface of the right great toe using the same local skin heating protocol described above, and imaged using a laser speckle contrast imager (LSCI) (also known as full-field laser perfusion imager, or FLPI).
Indiana University Melvin and Bren Simon Cancer Center (IUSCC)
Indianapolis, Indiana, United States
Syndney & Lois Eskenazi Health Center
Indianapolis, Indiana, United States
Differences in the mean size of axon reflexes between healthy women and women with breast cancer BEFORE starting Taxol.
* Hypothesis: (Cross-Sectional): There WILL NOT be a significant difference in the mean size of axon reflexes (expressed as a %CVCmax) in the great toe between healthy women and women with breast cancer before they start Taxol (i.e., Day 1). * Definitions/Notes: The mean size of axon reflexes will be determined by averaging the peak laser doppler values (in tissue perfusion units (TPUs)) that occur during a stable 30-90 second period after increasing the probe temperature to 42\*C. The maximum circulatory vascular conductance (%CVCmax) for each participant will be determined by dividing the raw TPU values by the participant's mean arterial blood pressure (MAP) during the axon reflex. The size of axon reflexes for each group will be then calculated by averaging the %CVCmax values corresponding to each individual's axon reflex for each group at that time point. Differences between groups in the size of axon reflexes at Day 1 will be compared using two-tailed t-tests, α=0.05.
Time frame: Day 1 (before participant's 1st Taxol infusion).
Differences in the mean size of axon reflexes between healthy women and women with breast cancer DURING Taxol therapy.
* Hypothesis (Cross-Sectional): There WILL be a significant difference in the mean size of axon reflexes generated on the palmar surface of the right great toe between healthy controls and women with breast cancer during their initial six weeks of Taxol therapy (i.e., day 14 and 42, respectively). * Notes: The mean size of axon reflexes during Taxol therapy will be determined by averaging the size of axon reflexes for participants in each group at day 14 and 42, respectively. Differences between groups in the size of axon reflexes at day 14 and 42 will be compared using two-tailed t-tests, α=0.05.
Time frame: Day 14 (week two of Taxol therapy) and Day 42 (week six of Taxol therapy).
Differences in the mean size of axon reflexes OVER TIME for women with breast during the initial six weeks of Taxol therapy.
* Hypothesis (Longitudinal): There WILL be a significant difference in the mean size of axon reflexes generated on the palmar surface of the great toe of women with breast cancer from (a) day 1 to day 14, (b) day 14 to day 42, and from (c) day 1 to day 42. * Note: Differences in mean size of axon reflexes over the course of Taxol therapy will be calculated using repeated-measures analysis of covariance (RM-ANCOVA).
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Self-reported signs \& symptoms of CIPN such as the presence and location of (1) tingling, (2) numbness, and (3) neuropathic pain, along with information about (4) deficits in vibration thresholds, and (5) loss of deep tendon reflexes will be assessed at each study visit using the 5-item, modified Total Neuropathy Score (mTNS).
Time frame: Day 1 (before participant's 1st Taxol infusion), day 14 (week two of Taxol therapy) and day 42 (week six of Taxol therapy).
Differences in the mean size of axon reflexes between healthy female controls OVER TIME the six-week study period.
* Hypothesis (Longitudinal): There WILL NOT be a significant difference in the size of axon reflexes on the palmar surface of the great toe of healthy female controls from(a) day 1 to day 14, (b) day 14 to day 42, and from (c) day 1 to day 42. * Note: Differences in mean size of axon reflexes over the course of Taxol therapy will be calculated using repeated-measures analysis of covariance (RM-ANCOVA).
Time frame: Day 1 (before participant's 1st Taxol infusion), Day 14 (week two of Taxol therapy) and Day 42 (week six of Taxol therapy).
Differences in the mean size of heat-evoked axon flares between healthy women and women with breast cancer BEFORE starting Taxol therapy.
* Hypothesis (Cross-Sectional): There WILL NOT be a significant difference in the mean size of heat-evoked axon flares generated on the palmar surface of the great toe between healthy women and women with breast cancer before starting Taxol therapy (day 1). * Note: A "heat-evoked axon flare" is defined as the area of increased cutaneous blood flow surrounding heat probe that is at least three standard deviations (3SD) above blood flow measured during prior to local skin heating. The size of each axon flare will be expressed in centimeters squared (cm2). The mean size of axon flares for each group will be calculated by averaging the size of axon flares for healthy women at baseline and the size of axon flares for women with breast cancer at day 1 (before starting Taxol). Differences in the mean size of axon flares between both groups at day 1 will be compared using two-tailed t-tests, α=0.05.
Time frame: Day 1 (before participant's 1st Taxol infusion).
Differences in the mean size of heat-evoked axon flares between healthy women and women with breast cancer DURING six weeks of study visits.
* Hypothesis (Cross-Sectional): There WILL be a significant difference in the mean size of heat-evoked axon flares generated on the palmar surface of the great toe between healthy controls and women with breast cancer DURING Taxol therapy at day 14 and 42 (respectively). * Note: Differences in the size of heat-evoked axon flares between healthy women and women with breast cancer at days 14 and 42 (respectively) will be compared using separate, two-tailed t-tests, α=0.05.
Time frame: Day 14 (week two of Taxol therapy) and Day 42 (week six of Taxol therapy).
Differences in the mean size of heat-evoked axon flares between women with breast cancer DURING their initial six weeks of Taxol therapy.
* Hypothesis (Longitudinal): There WILL be a significant difference in the mean size of heat-evoked axon flares generated on the palmar surface of great toe of women with breast cancer receiving Taxol from (a) day 1 to day 14, (b) day 14 to day 42, and from (c) day 1 to day 42. * Differences in the size of heat-evoked axon flares during Taxol therapy will be evaluated using repeated-measures analysis of variance (RM-ANOVA).
Time frame: Day 1 (before participant's 1st Taxol infusion), Day 14 (week two of Taxol therapy) and Day 42 (week six of Taxol therapy).
Differences in the size of heat-evoked axon flares for healthy women during the six-week study period.
* Hypothesis (Longitudinal): There WILL NOT be a significant difference in the size of heat-evoked axon flares (in cm2) generated on the great toe of healthy women from (a) day 1 to day 14, (b) day 14 to day 42, and from (c) day 1 to day 42. * Differences in the size of heat-evoked axon flares during Taxol therapy will be evaluated using RM-ANOVA.
Time frame: Day 1 (before participant's 1st Taxol infusion), Day 14 (week two of Taxol therapy) and Day 42 (week six of Taxol therapy).