What Are the Most Important Symptoms and Concerns of Patients with Indolent Non-Hodgkin's Lymphoma? Content Validation of the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy Lymphoma Symptom Index-18 (NFLymSI-18)

Background and aims: Although indolent B-cell non-Hodgkin's lymphoma (iNHL) may occur without symptoms, the presence of symptoms often provides an important signal of disease activity and may negatively affect quality of life. Thus, valid measures of disease symptoms are important for clinical trials and patient care. We aimed to assess whether the National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy Lymphoma Symptom Index-18 (NFLymSI-18) addresses a representative set of iNHL symptoms, treatment side effects, and emotional concerns.

Methods: Eligible patients had a confirmed iNHL diagnosis and had received one or more lines of treatment. Patients were recruited during clinic visits; informed consent was obtained from interested patients. Data were collected via face-to-face semi-structured interviews in which patients described their symptoms, treatment side effects, and emotional concerns related to iNHL. Qualitative data were analyzed using NVivo10 and results were mapped to the NFLymSI-18 to assess content validity. Patient and expert input from the development of the NFLymSI-18 and literature on iNHL symptoms were reviewed to further inform the content validity assessment.

Results: Data saturation was obtained by the 18th interview. Mean age of the 18 participants was 66.8 years (range 49-85). Fifty-six percent of the sample was male. Most participants (66.7%) had a college or advanced degree. When asked to describe their iNHL symptoms, patients most often discussed swelling (n=14), fatigue (n=12), and pain (n=8). The following symptoms were also mentioned by three patients each: anxiety, appetite loss, rash, sleep disruption, trouble breathing, and malaise. Treatment side effects spontaneously mentioned most often were fatigue (N=10), nausea (n=9), hair loss (N=8), cognitive problems (N=6), and weight loss (N=6). Emotional responses frequently mentioned included gratitude for life (N=11), worry (N=11), and feeling down (N=8). Mapping of NFLymSI-18 content to these patient concerns showed the instrument includes all of the most frequently-mentioned concerns. Some less frequently-mentioned concerns (i.e., rash, trouble breathing, malaise, fevers, hair loss, feeling down) are not covered by the instrument.

Conclusion and Summary: Patients with iNHL reported a wide range of disease related symptoms; however, swelling, fatigue and pain were most common. This study supports the representativeness of existing NFLymSI-18 items for patients with iNHL. In particular, the instrument shows strong validity for the most commonly referenced patient symptoms. The diversity of additional symptoms reported by patients is consistent with the heterogeneous symptomology of iNHL. These less-frequently-endorsed symptoms, side effects, and emotional concerns, could be added to the NFLymSI-18 if one wished to have a more inclusive assessment of concerns associated with iNHL.