Undetected Weight Loss Associates With Upstaging in Cancer Patients

Unintentional weight loss (UWL) is the primary diagnostic parameter for cancer cachexia in the clinic. Prompt identification of UWL can lead to earlier diagnoses and interventions for cancer. This study investigates the frequency and timing of UWL documentation and diagnoses in a cohort of cancer patients with measured UWL and sought to understand how recognition of UWL is related to stage of disease at cancer diagnosis.

A retrospective cohort of adult gastrointestinal and non-small cell lung cancer patients with measured UWL was evaluated. Body weight histories were manually reviewed for UWL. Patients with intentional weight loss, weight loss related to fluid status or weight loss with unclear intention were excluded. Records were assessed for the use of UWL-related International Classification of Diseases codes and documentation of UWL. ULW was considered missed if it was not documented or diagnosed by a healthcare provider. Associations between weight loss over time, documentation and/or diagnosis of UWL and stage of disease at cancer diagnosis were investigated through repeated measures mixed models and univariate and multivariate tests.

In total, 374 patients (24%) met the definition of UWL with an average weight loss of 8.6% ± 0.3%. UWL was missed in 161 (43%) patients with cancer cachexia. The odds of undetected UWL were greater in patients < 65 years old, with NSCLC, with obesity and who were White. In the 213 patients with recognized UWL, the documentation of UWL occurred approximately 7 months after their initial weight loss. The magnitude of weight loss was associated with cancer stage at cancer diagnosis (p < 0.0001). Patients who experienced ≥ 7.5% UWL pre-cancer diagnosis had a median cancer stage of 3 whereas patients who experienced < 7.5% UWL had a median cancer stage of 2 at cancer diagnosis (p < 0.0001). Relative to patients with ≥ 7.5% weight loss, the < 7.5% weight loss group had 73.7% more patients with Stage 1 disease (p < 0.0001) and 32.5% fewer patients with Stage 4 disease (p = 0.0006) resulting in median cancer stage increasing from Stages 2 to 3.

UWL was missed in 43% of cancer cachexia patients despite 8.6% ± 0.3% body weight loss prior to cancer diagnosis. When recognized, documentation of UWL did not occur until 7 months after weight loss initiation. A greater magnitude of UWL was associated with more advanced disease at cancer diagnosis. Recognition and timely diagnosis of UWL will increase the percentage of patients with curable, early-stage disease.