Radiation response of murine eccrine sweat glands

Efficacy of heparinoid moisturizer as a prophylactic agent for radiation dermatitis following radiotherapy after breast-conserving surgery: a randomized controlled trial

Background

The application of heparinoid moisturizer for 2 weeks following whole-breast radiotherapy (WBRT) was previously reported to significantly increase skin water content (WC) and help improve skin dryness and desquamation. The prospective open-label, randomized trial included an exploratory arm to investigate the preventive efficacy of heparinoid moisturizer for acute radiation dermatitis (ARD).

Methods

Between April 2011 and April 2013, patients receiving WBRT were assigned (1:2:2) to receive either: moisturizer for prophylaxis (group P), moisturizer starting 2 weeks after WBRT for treatment (group M), and no moisturizer (group C). This paper presents the results of comparison between the exploratory arm and no moisturizer group. Skin WC was measured prior to WBRT, on the last day of WBRT, and 2 weeks, 4 weeks and 3 months following WBRT. Signs and symptoms were also assessed.

Results

Comparing two groups, WC values were significantly higher in group P until 4 weeks following WBRT. At 2 weeks following WBRT, mean WC values in group P and C were 38.5 ± 6.1 arbitrary units (a.u.) and 30.2 ± 7.8 a.u., respectively (P < 0.001). In group C, dryness was more severe at 2 and 4 weeks following WBRT and desquamation more severe until 3 months following WBRT. However, the erythema score showed no difference between the two groups. Regarding symptoms, group C pain scores on the last day of WBRT were significantly higher than in group P (P < 0.030).

Conclusions

The preventive application of heparinoid moisturizer has the potential of reducing skin desquamation and dryness in patients receiving WBRT.

Randomized, prospective assessment of moisturizer efficacy for the treatment of radiation dermatitis following radiotherapy after breast-conserving surgery

Objective

The effect of heparinoid moisturizer use after acute skin damage for patients receiving whole-breast radiotherapy after lumpectomy is understudied.

Methods

A total of 30 patients were randomly assigned to receive heparinoid moisturizer (Group M), and 32 patients comprised the control group (Group C). Patients in Group M were instructed to apply heparinoid moisturizer from 2 weeks following whole-breast radiotherapy, and to continue to use the moisturizer until 3 months after completion of whole-breast radiotherapy. Group C patients were instructed to not apply any topical moisturizer during the study period. The relative ratio of skin water content ratio (RWCR_(t)= (I_t/N_t)/(I₀/N₀)) between irradiated and non-irradiated field was calculated. Signs and symptoms were also assessed. The primary endpoint was the difference in relative ratio of skin water content ratio between 2 and 4 weeks following whole-breast radiotherapy.

Results

In Group C, relative ratio of skin water content ratio dropped to 0.80 ± 0.15 at 2 weeks and maintained the low level at 4 weeks following whole-breast radiotherapy. Similarly, in Group M, relative ratio of skin water content ratio dropped to 0.81 ± 0.19 at 2 weeks (prior to application), however, it returned to baseline level (1.05 ± 0.23) at 4 weeks (2 weeks after application). The arithmetic difference of relative ratio of skin water content ratio in Group M was 0.24 ± 0.23 and was significantly larger than in Group C (0.06 ± 0.15; P < 0.01). Skin dryness and desquamation were less severe in Group M.

Conclusions

The application of heparinoid moisturizer for 2 weeks following whole-breast radiotherapy significantly increased water content and helped improve skin dryness and desquamation compared with no use of moisturizer.

The production and composition of rat sebum is unaffected by 3 Gy gamma radiation

PURPOSE

The aim of this work was to use metabolomics to evaluate sebum as a source of biomarkers for gamma-radiation exposure in the rat, and potentially in man. Proof of concept of radiation metabolomics was previously demonstrated in both mouse and rat urine, from the radiation dose- and time-dependent excretion of a set of urinary biomarkers.

MATERIALS AND METHODS

Rats were gamma-irradiated (3 Gy) or sham irradiated and groups of rats were euthanised at 1 h or 24 h post-irradiation. Sebum was collected by multiple washings of the carcasses with acetone. Nonpolar lipids were extracted, methylated, separated and quantitated using gas chromatography-mass spectrometry (GCMS). Metabolomic analysis of the GCMS data was performed using both orthogonal projection to latent structures-discriminant analysis and random forests machine learning algorithm.

RESULTS

Irradiation did not alter sebum production. A total of 35 lipids were identified in rat sebum, 29 fatty acids, five fatty aldehydes, and cholesterol. Metabolomics showed that three fatty acids, palmitic, 2-hydroxypalmitic, and stearic acids were potential biomarkers. Sebaceous palmitic acid was marginally statistically significantly elevated (7.5-8.4%) at 24 h post-irradiation.

CONCLUSIONS

Rat sebaceous gland appears refractory to 3 Gy gamma-irradiation. Unfortunately, collection of sebum shortly after gamma-irradiation is unlikely to form the basis of high-throughput non-invasive radiation biodosimetry in man.

Sweat gland function as a measure of radiation change

BACKGROUND

Radiotherapy may result in dryness of the skin even when no other change can be detected. We describe a system for recording the electrical conductance of skin as a measure of sweat gland function.

PATIENTS AND METHODS

In 22 normal volunteers close agreement was obtained between measurements obtained from comparable sites on both sides of the chest. Measurements were subsequently made in 38 patients treated by radiotherapy to one side of the chest for tumours of the breast or lung using one of five different fractionation schedules. Simultaneous readings were obtained from both sides of the chest with the non irradiated side acting as a control.

RESULTS

A dose response relationship was demonstrated: five patients who received the equivalent total dose of 15 Gy in 2-Gy fractions showed no change in conductance. Sixteen out of 23 who received an equivalent total dose of 42-46 Gy in 2-Gy fractions had a greater than 22% reduction in mean skin conductance compared with that of the control areas despite the skin appearing normal in the large majority. Marked changes in skin conductance were seen after higher total doses. In a prospective study 18 women receiving breast irradiation underwent weekly readings during treatment. A mean reduction of 40% in skin conductance was noted by the end of the second week of treatment prior to any clinical evidence of radiation change. Skin conductance returned to normal in 44% of patients by 6 months. In the remainder, those patients who showed the greatest reduction in skin conductance during treatment demonstrated the least recovery.

CONCLUSIONS

Changes in sweat gland function can be detected and quantified in skin which may otherwise appear normal. Differences may so be demonstrated between areas treated using different fractionation schedules and the method may be applied to the detection during radiotherapy of unusually sensitive patient.

Nonneoplastic disorders of the eccrine glands

Eccrine glands are uniquely susceptible to a variety of pathologic processes. Alteration in the rate of sweat secretion manifests as hypohidrosis and hyperhidrosis. Obstruction of the eccrine duct leads to miliaria. The excretion of drugs into eccrine sweat may be a contributory factor in neutrophilic eccrine hidradenitis (NEH), syringosquamous metaplasia (SSM), coma bulla, and erythema multiforme (EM). Alterations in the electrolyte composition of eccrine sweat can be observed in several systemic diseases, most notably cystic fibrosis. This article summarizes current knowledge of eccrine gland pathophysiology.