The current study sought to assess the severity, risk factors, and quality of life associated with CIPN in patients with cancer. The overall CIPN incidence was found to be moderate in this study compared with previous studies, which is likely due to the scales utilized (NTX and TNSn). Previous studies used quality of life scales to estimate CIPN, which generally contains a variety of general/broader items to assess neuropathy. Frequent symptoms of CIPN experienced by patients were autonomic symptoms such as constipation, dizziness and difficulty eating a meal because they get full too quickly. Sensory symptoms included tingling or numbness in fingers or toes, as well as difficulty standing or walking. Patients also reported motor symptoms, which included leg and hand weakness, cramping in the hands and feet, difficulty walking, and trouble fastening small buttons. Only 18.9% patients had trouble getting or keeping an erection. Several systematic reviews undertaken reported findings that were similar to ours [29]. Patients hardly ever reported serious or extremely serious concerns. This is congruent with other investigations where patients exhibited very little impact (not at all/a little) on the sensory, motor, and autonomic scores for the majority of the subjects [30]. One third of the patients in this study exhibited sensory symptoms (numbness, tingling, and neuropathic pain) that were only present in their toes and feet. These results align with those that were mentioned by Tofthagen et al. (2013), who found that the majority of patients taking paclitaxel or docetaxel only experienced numbness in their fingers and toes.
Furthermore, compared to other symptoms, individuals reported a higher level of autonomic symptoms such as constipation, dizziness, erectile dysfunction, and urine incontinence. Staff et al., (2017) reported that routinely-used chemotherapies such as taxanes, platinum compounds, vinca alkaloids, bortezomib, and thalidomide cause CIPN in a high proportion of patients, which supports the current study's findings. However, these findings contradict those of prior studies of cancer patients treated with chemotherapeutic-related regimens, which found that tingling or numbness in the fingers/hands, toes/feet were the most prevalent CIPN-related symptoms, and may limit activities and worsen QOL [32, 33].
In contrast to the current study, which found no correlation between age and the severity of CIPN, Mandepudi et al., (2019) reported that the severity of CIPN was more severe in older patients (age 60 years) (p = 0.40). This can be explained by the fact that sample in the preceding study belonged to the age group of 60 or older, whereas the mean age of the patients in the current study was (53.31). Congruent with the results of the current study, a different study revealed that alcohol use is the primary risk factor for the development of CIPN [15]. The results of the current study are incongruent with other studies which found that patients with chronic diseases (diabetes) had a higher risk of neuropathy [35]. The findings of our study, which found that FACT-GOG-NTx (neurotoxicity) was significantly correlated with the severity of symptoms and QOL, are consistent with Gordon et al., (2018) report of a highly significant inverse correlation between CIPN symptoms and QOL.
Results of the current study reported that the cognitive domain of QOL scored the highest mean among the participants. Additionally, constipation was the most reported symptom among participants. These findings are consistent with previous studies conducted by Oh et al. (2020) and Smith et al. (2019) which reported that CIPN and depression lead to restrictions in normal daily activities and a decrease in mobility and independence which may ultimately lead to constipation. It is possible that neuronal damage caused by CIPN causes constipation or cognitive problems in individuals. The association between autonomic neuropathy and constipation might be due to neurogenic bowel/dysautonomia, or constipation could be one of the symptoms of component autonomic neuropathy [39]. As a result of neuroinflammation, CIPN and cognitive abnormalities such as difficulties in remembering ("chemo fog”) may be linked to post-chemotherapy, which has been mentioned as a possible route for behavioral toxicities [39]. It will be intriguing to investigate these assumptions more concretely in the future and gain a better knowledge of the relationship between these parameters and CIPN. To help patients cope with the side effects of chemotherapy, healthcare practitioners should examine neurological function and give information on nutritional supplements, aerobic exercise, and balance training that may increase peripheral neurological function and improve everyday function [40].
The current study revealed that Fact/GOG-Ntx total score, sites of cancer metastasis, current radiotherapy treatment, and current chemotherapy were identified as being among the significant predictors of CIPN among Jordanian patients. These findings contradict those of Chan et al., (2019) who reported that platinum agents, taxanes, vinca alkaloids, bortezomib, and thalidomide analogues are drugs commonly implicated in development of CIPN. Additionally, the current findings are inconsistent with those of Seretny et al. (2014) who found that different chemotherapy drugs, genetic risk factors, smoking and abnormal creatinine clearance were significant predictors of CIPN. These are new variables implicated in the development of CIPN. Whether this finding is attributed to collinearity with CIPN or symptoms influencing the development (and/or severity) of CIPN is not yet clear.
The current study also aimed to determine the predictors of quality of life among CIPN patients in Jordan. The findings showed that Fact/GOG-Ntx total score, sites of cancer metastasis, previous radiotherapy treatment, and alcohol consumption were significant predictors of QOL among Jordanian cancer patients. This finding needs further elaboration in the future, although if a risk exists, it is probably minimal. However, the limited existing research does not differentiate the role of these variables in the type of neuropathy. Hence, this is a novel finding. These results are consistent with those of Hung et al., (2021), who reported that poor CIPN–related QOL was associated with more CIPN–sensory and more CIPN–motor impairment. Additionally, the current results contradict those of Bao et al. (2021) who found that acupuncture may improve CIPN-related symptoms and quality of life in cancer survivors with persistent CIPN. The role of alcohol use in the quality of life among CIPN patients is less clear, as contradictory findings have been presented in the literature, probably due to the inherent problems in measuring alcohol use accurately. The current findings suggest that alcohol consumption had some predictive effect on QOL. However, our sample had very few drinkers and this may have impacted on the results. Alcohol use may be associated with the development of neuropathy prior to the administration of chemotherapy, and we have seen that preexisting neuropathy was a key CIPN risk factor [18].
Some factors in the study had a minor predictive impact, which may affect the interpretation and generalizability of the findings and should be regarded as preliminary. Identification of risk factors and quality of life determinants in CIPN patients may help clinicians make chemotherapeutic treatment decisions that limit not just the development of CIPN but also the morbidity and health care use associated with a greater prevalence of CIPN. However, the level of knowledge in this field is not yet sufficient to permit such therapeutic judgments, and further study into understanding high quality of life in CIPN patients, including the creation of prediction models, is required. Other persistent risk variables, such as a higher BMI and obesity, were not evaluated in this investigation and should be considered in future models.
The study found moderate levels of QOL and CIPN among cancer patients in Jordan. It also revealed a significant relationship between CIPN and quality of life among the study participants, which is consistent with the conceptual framework used in our study. We used the Theory of Unpleasant Symptoms, which describes the patient's symptoms, the factors that influence them, and the consequences of how that experience impairs a patient's physical and/or cognitive performance.