Indolent lymphomas, including chronic lymphocytic leukemia/small lymphocytic lymphoma, marginal zone lymphoma, low-grade follicular lymphoma, and Waldenström macroglobulinemia, are slow-growing cancers often managed initially with a watchful waiting strategy. This approach avoids unnecessary side effects of early therapy but may negatively impact patients' quality of life (QoL) due to anxiety, uncertainty, and self-monitoring of symptoms. Previous research has suggested increased distress and greater QoL decline in patients under observation compared to those receiving treatment, despite similar or lower disease burden. Moreover, poor QoL has been shown to independently predict overall survival in non-Hodgkin lymphoma patients. However, there are limited data from Asian populations, where cultural factors, health insurance systems, and treatment access differ significantly. This study will evaluate the impact of watchful waiting on patient-reported QoL among Korean patients with indolent lymphoma, providing evidence specific to this population and healthcare setting.

This is an observational, patient-reported outcomes study of indolent lymphoma patients managed with a watch-and-wait strategy. Eligible participants include adults (≥19 years) diagnosed at Seoul National University Hospital with chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), marginal zone lymphoma (MZL), follicular lymphoma (FL), or Waldenström macroglobulinemia/lymphoplasmacytic lymphoma (WM/LPL), according to WHO criteria. Patients must be recently diagnosed, currently under observation, and able to understand and complete the survey independently. Patients receiving active systemic therapy or with cognitive impairment precluding self-report are excluded.

The target enrollment is up to 150 participants, estimated based on the number of eligible outpatients seen over a 3-month period. Recruitment will occur during outpatient visits, where physicians will introduce the study. After providing written informed consent, patients will complete validated questionnaires (EORTC QLQ-C30, EQ-5D-5L, and disease-specific modules such as QLQ-CLL17 or QLQ-NHL) to assess quality of life, distress, and emotional well-being. Clinical and demographic data (e.g., age, sex, diagnosis, stage, ECOG, marital status, outpatient interval) will also be collected from medical records. Surveys are expected to take at least 20 minutes and will be completed by patients during outpatient waiting periods.

The study involves no therapeutic intervention and poses no risks beyond minimal psychological burden comparable to daily life or routine clinical assessments. Data will be analyzed descriptively and statistically to evaluate the impact of observation on quality of life and psychosocial outcomes. Unlike prior studies, this investigation will focus on Korean patients, reflecting Asian cultural context, local health insurance structure, and treatment accessibility, thereby providing novel and clinically meaningful insights.

Inclusion Criteria:

• Adults ≥19 years old.
• Diagnosed with indolent lymphoma (CLL/SLL, MZL, FL, or WM/LPL) at Seoul National University Hospital according to WHO criteria.
• Currently managed with watch-and-wait (no active systemic therapy).
• Able to understand and independently complete the study questionnaires.
• Provide voluntary informed consent.

Exclusion Criteria:

• Receiving active systemic anti-lymphoma therapy at the time of enrollment.
• Cognitive impairment or other condition preventing independent completion of the questionnaire.

Patients diagnosed with indolent lymphoma (CLL/SLL, MZL, FL, or WM/LPL) at Seoul National University Hospital who are managed with a watch-and-wait strategy and able to provide informed consent and complete patient-reported outcome surveys.

Individual participant data (IPD) will not be shared in order to protect patient confidentiality, as the dataset contains sensitive clinical and patient-reported information. Only aggregate results will be disseminated through publications and presentations.