Evaluating the role of serotonin in hot flashes after breast cancer using acute tryptophan depletion

Phytochemicals modulate carcinogenic signaling pathways in breast and hormone-related cancers

Over the years, nutrition and environmental factors have been demonstrated to influence human health, specifically cancer. Owing to the fact that cancer is a leading cause of death worldwide, efforts are being made to elucidate molecular mechanisms that trigger or delay carcinogenesis. Phytochemicals, in particular, have been shown to modulate oncogenic processes through their antioxidant and anti-inflammatory activities and their ability to mimic the chemical structure and activity of hormones. These compounds can act not only by influencing oncogenic proteins, but also by modulating noncoding RNAs such as microRNAs and long noncoding RNAs. Although we are only beginning to understand the complete effects of many natural compounds, such as phytochemicals, researchers are motivated to combine these agents with traditional, chemo-based, or hormone-based therapies to fight against cancer. Since ongoing studies continue to prove effective, herein we exalt the importance of improving dietary choices as a chemo-preventive strategy.

Risk factors, pathophysiology, and treatment of hot flashes in cancer

Hot flashes are prevalent and severe symptoms that can interfere with mood, sleep, and quality of life for women and men with cancer. The purpose of this article is to review existing literature on the risk factors, pathophysiology, and treatment of hot flashes in individuals with cancer. Electronic searches were conducted to identify relevant English-language literature published through June 15, 2012. Results indicated that risk factors for hot flashes in cancer include patient-related factors (eg, age, race/ethnicity, educational level, smoking history, cardiovascular risk including body mass index, and genetics) and disease-related factors (eg, cancer diagnosis and dose/type of treatment). In addition, although the pathophysiology of hot flashes has remained elusive, these symptoms are likely attributable to disruptions in thermoregulation and neurochemicals. Therapies that have been offered or tested fall into 4 broad categories: pharmacological, nutraceutical, surgical, and complementary/behavioral strategies. The evidence base for this broad range of therapies varies, with some treatments not yet having been fully tested or showing equivocal results. The evidence base surrounding all therapies is evaluated to enhance hot flash treatment decision-making by clinicians and patients.

Long-term chinese herbs decoction administration for management of hot flashes associated with endocrine therapy in breast cancer patients

OBJECTIVE

To evaluate the effect of Chinese herbs decoction Shu-Gan-Liang-Xue on endocrine therapy- associated hot flashes symptom in breast cancer patients.

METHODS

Sixty-six patients with breast cancer receiving adjuvant endocrine therapy were categorized to two groups, the control group received endocrine therapy alone, the other group is administered with Chinese herbs decoction Shu-Gan-Liang-Xue besides the endocrine therapy: Shu-Gan-Liang-Xue decoction was administered above 6 months per year for more than 2 years. Frequency of hot flashes per day was recorded, and the effect of Shu-Gan-Liang-Xue decoction on hot flashes symptom being assessed with Kupperman Scoring Index.

RESULTS

Sixty cases were analyzed, 32 cases in endocrine therapy combining Chinese herbs decoction group, 28 cases in mere endocrine therapy group. For hot flashes symptom, in Chinese herbs decoction administration group, 7 cases (21.9%) reported symptom disappeared, 22 cases (68.7%) reported symptom alleviated, 3 cases (9.4%) reported symptom not changed; in endocrine therapy alone group, 5 cases (17.9%) reported symptom disappeared, 13 cases (46.4%) reported symptom alleviated, 10 cases (10/28, 35.7%) reported symptom not changed. The difference between two groups was statistically significant (P=0.013). For sleeping disorder, in Chinese herbs decoction administration group, 27 cases (84.4%) reported symptom improved, 5 cases (15.6%) reported no change; in endocrine therapy alone group, 16 cases (57.1%) symptom improved, 12 cases (42.9%) reported no change in sleeping disorder (P=0.019), the difference was also of significance statistically.

CONCLUSION

Long-term Chinese herbs decoction administration remarkably improved hot flashes symptom and sleeping disorder associated with endocrine therapy, meanwhile without definite toxicity and influence on the risk of recurrence of tumor.

How are Interactions Taken into Account in Studies on Conventional and Complementary Therapies for Breast Cancer Patients with Menopausal Complaints?

Introduction: Postmenopausal symptoms in breast cancer patients undergoing antihormone treatment lead to high drop-out rates from the therapy. From the therapeutic point of view, methods of both conventional and complementary medicine are concerned. Interactions are being discussed in cases of natural substances. However, they are also relevant for conventional medical substances. The aim of this analysis is to answer the question as to what extent potential interactions are taken into account in clinical studies and reviews on supportive therapies. Materials and Methods: Clinical studies and reviews were identified by means of a systematic search and analysed with regard to the consideration of potential interactions. Results: Altogether 46 clinical studies and one Cochrane review were found. Among the 35 studies on conventional drug therapies, 5 (14 %) took possible interactions into account. Among the 17 studies on complementary medicine, there were 2 (11.7 %) such publications. The Cochrane review did not mention interactions. Discussion: For future studies in which interactions cannot be excluded, a strategy to control for their clinically relevant consequences should be developed. The present authors suggest that the use of survival and recurrence data as secondary endpoints, also for studies on purely supportive therapies, is a reasonable approach. The resulting considerations for study routines are listed thematically.

Designing cost-efficient randomized trials by using flexible recruitment strategies

Background

Sample size planning for clinical trials is usually based on detecting a target effect size of an intervention or treatment. Explicit incorporation of costs into such planning is considered in this article in the situation where effects of an intervention or treatment may depend on (interact with) baseline severity of the targeted symptom or disease. Because much larger sample sizes are usually required to establish such an interaction effect, investigators frequently conduct studies to establish a marginal effect of the intervention for individuals with a certain level of baseline severity.

Methods

We conduct a rigorous investigation on how to determine optimum baseline symptom or disease severity inclusion criteria so that the most cost-efficient design can be used. By using a regression model with an interaction term of treatment by symptom severity, power functions were derived for various levels of baseline symptom severity. Computer algorithms and mathematical optimization were used to determine the most cost-efficient research designs assuming either single- or dual-stage screening procedures.

Results

In the scenarios we considered, impressive cost savings can be achieved by informed selection of baseline symptom severity via the inclusion criteria. Further cost-savings can be achieved if a two stage screening procedure is used and there are some known, relatively inexpensively collected, pre-screening information. The amount of total cost savings are shown to depend on the ratio of the screening and intervention costs. In our investigation, we assumed that: 1) the cost of approaching available subjects for screening is constant, and 2) all variables are normally distributed. There is a need to carry out further investigations with more relaxed assumptions (e.g., skewed data distribution).

Conclusions

As cost becomes a more and more prominent issue in modern clinical trials, cost-saving strategies will become more and more important. Strategies, such as the ones we propose here, can help to minimize costs while maximizing knowledge generation.

Escitalopram treatment of menopausal hot flashes

OBJECTIVE

The aim of this study was to determine the effects of 10 and 20 mg/day of escitalopram on objectively recorded hot flashes and on the rectal temperature threshold for sweating.

METHODS

Two studies were performed: 16 women received 10 mg/day and 26 women received 20 mg/day escitalopram for 8 weeks. They were randomly assigned in equal numbers to receive active drug or placebo in a double-blind fashion. Hot flash frequency was measured with an ambulatory recorder during the first 3 weeks and during the 8th week of the study. Rectal temperature threshold for sweating was measured during the 1st and 8th weeks of the study using published methods.

RESULTS

In the first study, there were no significant effects whatsoever for any measure. In the second study, the escitalopram group showed an average decline in hot flash frequency of 14.4%, whereas the placebo group showed an average increase of 6.7% (P < 0.05). However, there were no significant effects across time for either group. There were no significant effects whatsoever for rectal temperature sweating thresholds.

CONCLUSIONS

Escitalopram at 10 or 20 mg/day is not effective in the treatment of menopausal hot flashes.

Concordance between self-reported and sternal skin conductance measures of hot flushes in symptomatic perimenopausal and postmenopausal women: a systematic review

OBJECTIVE

Sternal skin conductance is considered the gold standard in hot flush and night sweat measurement, but results sometimes differ from women's own self-reports. To date, there has been no systematic review of concordance between sternal skin conductance and self-report measures. An exploratory meta-analysis was conducted to quantify concordance between these measures and to explore the reasons for discordance between them.

METHODS

A search of Medline, EMBASE, Web of Science, and PsychInfo from inception to December 2009 was conducted. Studies that measured self-reported hot flushes and/or night sweats and sternal skin conductance concurrently in symptomatic perimenopausal and postmenopausal women were retained for data extraction. Studies were included if data on concordance between the two measures were available.

RESULTS

Concordance rates overall were 29%, but variability between studies was too broad to identify a single typical concordance rate. However, concordance rates for ambulatory monitoring were more homogeneous and also had a 29% concordance rate. Nonambulatory studies tended to result in more concordant hot flushes (54%) than ambulatory studies did, and night sweats tended to be under-reported more often than over-reported (46% and 22%, respectively).

CONCLUSIONS

Concordance rates were typically lower than early reports of sternal skin conductance measures but were highly variable between studies. Possible measurement error and study conditions might partly explain the discordance and variation in study findings, but further exploration of the effects of symptom perception is warranted. Use of both measures concurrently is likely to achieve more reliable and valid measurement of hot flushes and night sweats than either measure alone.

Quality-of-life measurement in randomized clinical trials in breast cancer: an updated systematic review (2001-2009)

BACKGROUND

Quality-of-life (QOL) measurement is often incorporated into randomized clinical trials in breast cancer. The objectives of this systematic review were to assess the incremental effect of QOL measurement in addition to traditional endpoints (such as disease-free survival or toxic effects) on clinical decision making and to describe the extent of QOL reporting in randomized clinical trials of breast cancer.

METHODS

We conducted a search of MEDLINE for English-language articles published between May-June 2001 and October 2009 that reported: 1) a randomized clinical trial of breast cancer treatment (excluding prevention trials), including surgery, chemotherapy, hormone therapy, symptom control, follow-up, and psychosocial intervention; 2) the use of a patient self-report measure that examined general QOL, cancer-specific or breast cancer-specific QOL or psychosocial variables; and 3) documentation of QOL outcomes. All selected trials were evaluated by two reviewers, and data were extracted using a standardized form for each variable. Data are presented in descriptive table formats.

RESULTS

A total of 190 randomized clinical trials were included in this review. The two most commonly used questionnaires were the European Organization for Research and Treatment of Cancer QOL Questionnaire and the Functional Assessment of Cancer Therapy/Functional Assessment of Chronic Illness Therapy. More than 80% of the included trials reported the name(s) of the instrument(s), trial and QOL sample sizes, the timing of QOL assessment, and the statistical method. Statistical power for QOL was reported in 19.4% of the biomedical intervention trials and in 29.9% of the nonbiomedical intervention trials. The percentage of trials in which QOL findings influenced clinical decision making increased from 15.2% in the previous review to 30.1% in this updated review for trials of biomedical interventions but decreased from 95.0% to 63.2% for trials of nonbiomedical interventions. Discordance between reviewers ranged from 1.1% for description of the statistical method (yes vs no) to 19.9% for the sample size for QOL.

CONCLUSION

Reporting of QOL methodology could be improved.

Evaluating the role of serotonin on neuropsychological function after breast cancer using acute tryptophan depletion

Although cognitive dysfunction is a prevalent and disruptive problem for many breast cancer survivors (BCSs), little research has examined its etiology. One potential mechanism that remains to be explored is serotonin. Serotonin has been implicated in normal and dysfunctional cognitive processes, and serotonin levels are significantly affected by estrogen withdrawal, a common side effect of breast cancer treatment. However, no study has evaluated serotonin's role on cognitive dysfunction in BCSs. The purpose of this study was to examine the role of serotonin in cognitive dysfunction in survivors by lowering central serotonin concentrations via acute tryptophan depletion (ATD). Based on previous research in noncancer populations, we hypothesized that alterations in central serotonin levels would induce cognitive dysfunction in these women controlling for confounding characteristics such as fluctuating mood and glucose levels. Secondarily, we explored whether genetic variations in serotonin genes would partly explain ATD. Participants included 20 female BCSs, posttreatment for nonmetastatic breast cancer, who received ATD or control in a double-blind, crossover design. Cognitive performance was measured at the 5-hr tryptophan/serotonin nadir on each test day using standardized neuropsychological tests. Specific impairment was noted in episodic memory (delayed recall) and motor speed during ATD versus control. ATD did not alter new learning (immediate recall), working memory, verbal fluency, or information processing speed. Findings suggest that serotonin may play a critical role in memory consolidation and motor functioning in BCSs.