Under-reporting of subjective symptoms and its prognostic value: a pooled analysis of 12 cancer clinical trials

BACKGROUND

Oncologists tend to under-report subjective symptoms during cancer treatment. This study describes the under-reporting rate of selected symptoms and explores its association with overall survival (OS). A secondary aim is to test the association of patient-reported symptoms with OS.

PATIENTS AND METHODS

This is a post hoc analysis on data pooled from 12 randomized trials, promoted by the National Cancer Institute of Naples (Italy), enrolling patients between 2002 and 2019, with published primary analyses. Occurrence and grade of six side-effects (anorexia, nausea, vomiting, constipation, diarrhea and fatigue) reported by physicians were compared with corresponding symptoms reported by patients in quality-of-life (QoL) questionnaires. Under-reporting was defined as the rate of cases reported grade 0 by the physician while grade ≥1 by the patient. Prognostic value was tested in a multivariable model stratified by trial, including age, sex and performance status as confounders. A landmark threshold was defined for OS analyses.

RESULTS

3792 patients with advanced lung, ovarian, pancreatic, breast or colorectal cancer were pooled; 2603 (68.6%) were eligible having at least one toxicity assessment and one QoL questionnaire, before the first planned disease restaging. Concordance between physicians' and patients' reporting was low with Cohen's k coefficients ranging from 0.03 (fatigue) to 0.33 (vomiting). Under-reporting ranged from 52.7% (nausea) to 80.5% (anorexia), and was not associated with OS. Patient-reported anorexia, vomiting and fatigue ('a little' or more) were significantly associated with shorter OS.

CONCLUSIONS

Under-reporting of treatment side-effects is frequent, but it does not affect OS. Patients' reported symptoms should be used for prognostic evaluation.

Subgroup analyses in randomized phase III trials of systemic treatments in patients with advanced solid tumours: a systematic review of trials published between 2017 and 2020

BACKGROUND

Subgroup analyses of randomized controlled trials are very common in oncology; nevertheless, the methodological approach has not been systematically evaluated. The present analysis was conducted with the aim of describing the prevalence and methodological characteristics of the subgroup analyses in randomized controlled trials in patients with advanced cancer.

METHODS

A systematic literature search using PubMed was carried out to identify all phase III randomized controlled trials conducted in adult patients affected by locally advanced or metastatic solid tumours, published between 2017 and 2020.

RESULTS

Overall, 253 publications were identified. Subgroup analyses were reported in 217 (86%) publications. A statistically significant association of presence of subgroup analysis with study sponsor was observed: subgroup analyses were reported in 157 (94%) for-profit trials compared with 60 (70%) non-profit trials (P < 0.001). Description of the methodology of subgroup analysis was completely lacking in 82 trials (38%), only cited without methodological details in 100 trials (46%) and fully described in 35 trials (16%). Forest plot of subgroup analyses for the primary endpoint was available in 195 publications (77%). Among publications with reported forest plots, the median number of subgroups for primary endpoint was 19 (range 6-78). Out of the 217 publications with subgroup analyses, authors discuss the heterogeneity of treatment effect among different subgroups in 173 publications (80%), although a formal test for interaction for subgroup analysis of primary endpoint was reported for at least one variable only in 60 publications (28%). Correction for multiplicity was explicitly carried out only in nine trials (4%).

CONCLUSIONS

The very high prevalence of subgroup analyses in published papers, together with their methodological weaknesses, makes advisable an adequate education about their correct presentation and correct reading. More attention about proper planning and conduction of subgroup analysis should be paid not only by readers, but also by authors, journal editors and reviewers.