Mitomycin C br Conclusion GI cancers affect the gastric myoe
Conclusion: GI cancers affect the gastric myoelectric activity, decreasing normogastria and slow wave coupling. These patients do not show adequate gastric motility response to food. Impaired gastric electric motility may result from cancer-induced autonomic disturbances.
Electrogastrography (EGG) is a non-invasive reproducible method for recording gastric myoelectric activity with the electrodes placed on the abdominal skin over the stomach. EGG provides information on gastric function in both fasted and fed state [1–3]. Normal frequency of rhythmic electrical depolarizations (slow waves) approximates 3 cycles per minute (cpm) [1–3]. Slow waves control maximal frequency and direction of distal stomach motility. EGG may be a useful tool for evaluating and further monitoring of functional gastrointestinal (GI) disorders [1–5].
Gastric motility may be assessed on the basis of determining gastric emptying and recording gastric myoelectric activity. While the former
technique is suitable solely for assessing postprandial motor status, the latter can accurately determine gastric motor function in both pre-prandial and postprandial state [6–10]. Authors of previous studies evaluated gastric emptying and myoelectric activity at the same time point, and searched for a link between gastric dysmotility and clinical presentation of patients with various disorders [4,5,9,11–14]. Delayed gastric emptying was shown to be linked to EGG abnormalities, pri-marily to a decrease in the percentage of normal slow gastric waves and a postprandial increase in Mitomycin C power (DP). In an experimental study, each slow gastric wave was associated with a contraction, which, however, was lost in the case of dysrhythmia. Furthermore, a relative increase in DP of EGG was shown to be related to greater contractile activity of the stomach . These observations were confirmed in
Corresponding author at: Department of Oncology, Cracow University Hospital, 10 Sniadeckich St., 31-531, Cracow, Poland.
E-mail address: [email protected] (A.L. Zygulska).
1 Passed away before the study was finished.
Available online 21 November 2018
human studies [6,7]. An increase in the percentage of normal slow waves, dominant frequency (DF) and DP, as well as a concomitant decrease in the severity of dysrhythmia, were typically observed in healthy subjects as a gastric myoelectric response to food [16,17]. Gastric myoelectric activity has been sporadically studied in GI cancer patients [13,18]. Statistically significant positive correlations were found between the feeling of fullness in the epigastric region and the percentage of preprandial bradygastria in gastric cancer and rectal cancer patients [18–21]. On the other hand, tachygastria and reduction of gastric motility were documented after neoadjuvant chemor-adiotherapy due to esophageal cancer. Individuals with this malignancy showed a decrease in DF and lower prevalence of normogastria at 3 and 6 months post-surgery, with subsequent normalization of these para-meters at 12 months . In another study, gastric cancer patients after total or distal gastrectomy presented with lower power amplitude and lower power content of normogastria than the healthy controls and individuals subjected to total colectomy . According to literature, tachygastria, bradygastria, dysrhythmia and gastric outlet obstruction may occur in up to 88.6% of cancer patients, and abnormal EGG find-ings co-exist with dysmotility-like symptoms .
Frequency domain analysis of heart rate variability (HRV) provides information on autonomic balance and is suitable for quantification of sympathetic and parasympathetic tone. HRV monitoring can be used to non-invasively examine the cardiac autonomic innervation and vege-tative modulation of the sinus node. Hence, HRV is often included in studies on various autonomic disorders. Moreover, this method seems to be appropriate for evaluating cancer-specific changes in the auto-nomic activity [23,24].
Both, sympathetic and parasympathetic, components of the auto-nomic nervous system play vital roles during development and spread of solid tumors, albeit at different stages of tumorigenesis. Likewise in leukocyte and fibroblast migration, neurotransmitters also regulate the migratory activity of cancer cells. The phenomenon refers to cancer cells migrating along nerve fibers as perineural invasion, that is asso-ciated with poorer prognosis [25,26].
The aim of this study was to analyze an association between gastric motility and dyspeptic symptoms in patients with colorectal and gastric malignancies, who additionally had performed the estimation of the autonomic nervous system activity based on HRV. To the best of our knowledge, it is the first published study analyzing changes of gastric myoelectric activity in this group of cancer patients.