br Gastrointestinal symptoms Group A Group B
Gastrointestinal symptoms Group A Group B Group C p p p
Legend: Me – median value; Min – minimum; max – maximum; p < 0.05 – statistical significant differences between groups A&B&C (ANOVA analysis). NS – nonsignificant.
Comparison of frequency domain HRV parameters in patients groups with cancer and healthy controls.
Parameter Group A Group B Group C Controls p p p p
A&B A&Control B&Control C&Control
Legend: Me – median value; min – minimum; max – maximum; p < 0.05 - significant differences between groups A&B&C&Control; The significant differences between groups A&C and B&C were not found, NS – nonsignificant statistical.
preservation . In another study , total gastrectomy was asso-ciated with complete loss of a 3-cpm power peak or a significant de-crease in its amplitude. In contrast, no significant total gastrectomy-related changes were observed in the case of an 11-cmp power peak characteristics. Moreover, patients after subtotal gastrectomy and gas-tric tube formation presented with lower postprandial values of post-operative to preoperative power ratio at 3-cpm . Our findings are partially consistent with these results, since the patients after distal gastrectomy also showed gastric myoelectric activity disturbances. However, in the study by Hayashi et al. , motility of the residual stomach was the same as for the non-resected stomach whenever more than half of the gastric volume was preserved (i.e. if the length of the greater curvature of the residual stomach was > 20 cm). In contrast, our patients presented with EGG disturbances, namely with a decrease in the percentages of normogastria time and ACSWC, as well as with an increase in DP, when examined in a preprandial state.
Chang et al.  demonstrated that contrary to the controls, gastric cancer patients do not show a postprandial increase in the DF, present with marked power response after meal and obvious power ratio. Ad-vanced gastric cancer turned out to be the only factor contributing to the evident postprandial increase in the DP. Our findings are consistent with those presented by Chang et al., since up to 60% of our patients showed an abnormal response to the test meal . The most likely pathomechanism leading to these abnormalities is mechanical damage of Cajal's 2-NBDG or a decrease in the number thereof, associated with either gastrectomy or the presence of gastric cancer itself. The decrease in the number of Cajal’s cell might induce changes in the gastric myoelectric activity of our patients. Importantly, the EGG abnormalities were found not only in the gastric cancer patients, but also in the in-dividuals with colorectal malignancies. In our opinion, abnormalities observed in the latter group might reflect an influence of the brain-gut axis on the regulation of GI motility or result from direct injury of the ENS.
Central nervous system (CNS) communicates with the intestines directly via the brain-gut axis. CNS recognizes GI inflammation asso-ciated with the presence of colorectal tumor as an activation of vagal afferent signaling. Inflammatory signals originating from the large bowel may significantly alter peripheral neuronal signaling, which re-sults in both peripheral and central sensitization. This phenomenon is reflected by an enhanced afferent neuronal activation [35,36]. Both, cancer itself and anticancer surgery, may result in acute or chronic inflammation of the colon or rectum.
Chemotherapy may induce upper GI symptoms suggestive of moti-lity disorders. A study of patients subjected to Roux-en-Y reconstruction after previous Billroth gastrectomy and chemotherapy showed that such dyspeptic symptoms are associated with abnormal electrogastro-graphic recordings [37,38]. In another study, conducted by Chasen and Bharqava , patients with advanced cancer, either with normal or abnormal ECG findings, presented with loss of appetite or were listless for food intake, nausea, vomiting and early satiety. The most commonly observed dysmotility-like symptoms included in the Dyspepsia Symptom Severity Index were frequent burping and belching, bloating, feeling full after meals, inability to finish a normal-sized meal, ab-dominal distention and postprandial nausea. In turn, the list of the most frequent reflux- and ulcer-like symptoms included regurgitation of bitter fluid and abdominal pain before meals . In contrast, we did not find the evidence of dyspeptic symptoms in the majority of our GI cancer patients. The most frequent ailment was bloating in the epi-gastric region, reported by 52.75% of all cancer patients. Epigastric pain, feeling of food retention in the stomach, and overfilling of the epigastric region were primarily reported by individuals with gastric malignancies. In turn, bloating was the main dyspeptic symptom in colorectal cancer patients. Perhaps, these discrepancies between our findings and the results published by Chasen and Bharqava  should be attributed to better performance status of our patients. In addition, our patients were not examined during ongoing chemotherapy, but only in a stable period.