Validity of the chemotherapy-induced peripheral neuropathy self-check sheet

Assessing chemotherapy-induced peripheral neuropathy with patient reported outcome measures: a systematic review of measurement properties and considerations for future use

PURPOSE

Chemotherapy-induced peripheral neuropathy (CIPN) is a common toxicity of cancer treatment, with potential to significantly impact cancer survivors' long-term quality of life. Patient reported outcome measures (PROMs) are increasingly utilised to evaluate CIPN. However, guidance remains lacking on how to identify fit for purpose PROMs with considerations necessarily differing when used in various research and in-clinic contexts. This study aimed to evaluate evidence about CIPN PROMs measurement properties and propose considerations to optimize CIPN PROM selection for each purpose.

METHODS

A systematic review was conducted to identify literature assessing measurement properties of CIPN PROMs. These were evaluated against Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) criteria and International Society for Quality of Life minimum standards. Risk of Bias (RoB) was assessed using the COSMIN RoB checklist.

RESULTS

Thirty-nine papers evaluating measurement properties of 13 PROMs were included. The European Organization for Research and Treatment of Cancer Quality of Life Chemotherapy-Induced Peripheral Neuropathy Questionnaire (QLQ-CIPN20) and Functional Assessment of Cancer Therapy/Gynecologic Oncology Group-Neurotoxicity (FACT/GOG-Ntx) were the most commonly investigated PROMs and had the most measurement properties meeting established criteria.

CONCLUSION

The use of the QLQ-CIPN20 and FACT/GOG-Ntx to assess CIPN in research settings has the most supporting evidence. However other considerations including study aims, endpoints and target population also factor into PROM selection and need to be considered more often when determining the most suitable outcome measure. Evidence of CIPN PROMs use in clinical practice is limited and their adoption to individual-patient level management requires more evaluation.

Clinical and biochemical markers in CIPN: A reappraisal

The increased survival of cancer patients has raised growing public health concern on associated long-term consequences of antineoplastic treatment. Chemotherapy-induced peripheral neuropathy (CIPN) is a primarily sensory polyneuropathy, which may be accompanied by pain, autonomic disturbances, and motor deficit. About 70% of treated cancer patients might develop CIPN during or after the completion of chemotherapy, and in most of them such complication persists after six months from the treatment. The definition of the potential risk of development and resolution of CIPN according to a clinical and biochemical profile would be certainly fundamental to tailor chemotherapy regimen and dosage on individual susceptibility. In recent years, patient-reported and clinician-related tools along with quality of life instruments have been featured as primary outcomes in clinical setting and randomized trials. New studies on metabolomics markers are further pursuing accurate and easily accessible indicators of peripheral nerve damage. The aim of this review is to outline the strengths and pitfalls of current knowledge on CIPN, and to provide a framework for future potential developments of standardized protocols involving clinical and biochemical markers for CIPN assessment and monitoring.

Overview and critical revision of clinical assessment tools in chemotherapy-induced peripheral neurotoxicity

Chemotherapy-induced peripheral neurotoxicity (CIPN) is a major toxicity of cancer treatment, leading to dose reduction and premature treatment cessation, potentially affecting patient function, and quality of life. The development of accurate and sensitive assessment tools for CIPN is essential to enable clinical monitoring during treatment, follow-up of long-term outcomes and measurement of toxicity in clinical trials. This review examines CIPN clinical assessment scales incorporating clinician-based, composite, and patient-reported outcomes (PROs), providing a systematic review of their properties and an updated critical analysis of recommendations on current evidence for their use. This systematic review of CIPN assessment tools identified 50 papers containing 41 assessment tools, across 4 categories (common toxicity criteria; composite neurological scale; PROs; pain scale). The majority of these tools were PROs, underscoring the importance of patient-based assessment of symptoms. While there has been considerable work in the field over the past 10 years, this review highlights significant gaps, including a lack of evaluation of responsiveness and problematic neuropathic pain evaluation. There remains a need for consensus on the best available tool and the need to modify existing instruments to improve utility.

Development and validation of the comprehensive assessment scale for chemotherapy-induced peripheral neuropathy in survivors of cancer

Background

Appropriate assessment is essential for the management of chemotherapy-induced peripheral neuropathy (CIPN), an intractable symptom that cannot yet be palliated, which is high on the list of causes of distress for cancer patients. However, objective assessment by medical staff makes it easy to underestimate the symptoms and effects of CIPN in cancer survivors. As a result, divergence from subjective evaluation of cancer survivors is a significant problem. Therefore, there is an urgent need to develop a subjective scale with high accuracy and applicability that reflects the experiences of cancer patients. We developed a comprehensive assessment scale for CIPN in cancer survivors, named the Comprehensive Assessment Scale for Chemotherapy-Induced Peripheral Neuropathy in Survivors of Cancer (CAS-CIPN), and demonstrated its reliability and validity.

Methods

We developed a questionnaire based on qualitative studies of peripheral neuropathy in Japanese cancer patients and literature review. Twelve cancer experts confirmed the content validity of the questionnaire. A draft version comprising 40 items was finalized by a pilot test on 100 subjects. The participants in the present study were 327 Japanese cancer survivors. Construct validity was determined by factor analysis, and internal validity by confirmation factor analysis and Cronbach’s α.

Results

Factor analysis showed that the structure consisted of 15 items in four dimensions: “Threatened interference in daily life by negative feelings”, “Impaired hand fine motor skills”, “Confidence in choice of treatment/management,” and “Dysesthesia of the palms and soles.” The CAS-CIPN internal consistency reliability was 0.826, and the reliability coefficient calculated using the Spearman-Brown formula [q = 2r/(1 + r)] was 0.713, confirming high internal consistency and stability. Scores on this scale were strongly correlated with Gynecologic Oncology Group-Neurotoxicity scores (r = 0.714, p < 0.01), confirming its criterion-related validity.

Conclusions

The CAS-CIPN is an assessment tool with high reliability and validity for the comprehensive evaluation of CIPN in cancer survivors. The CAS-CIPN is simple to use, and can be used by medical professionals for appropriate situational assessment and intervention.