In this parallel, two-arm randomized controlled trial (RCT), 140 female patients with advanced-stage breast cancer and clinical features of cachexia will be randomized using block-stratified allocation into an intervention group (n = 70) and a control group (n = 70). The intervention group will receive standard oncological care along with personalized dietary counseling and monthly nutritional monitoring for six months, whereas the control group will receive standard care alone. The severity of cachexia will be assessed at baseline and follow-up using the Mini-CASCO tool, which will evaluate five domains: body composition, inflammatory-metabolic profile (C-reactive protein, serum albumin, hemoglobin, absolute lymphocyte count), physical performance (Eastern Cooperative Oncology Group [ECOG] status), anorexia (Simplified Nutritional Appetite Questionnaire [SNAQ]), and quality of life (European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 [EORTC QLQ-C30]).

This randomized controlled trial evaluates the impact of individualized dietary counseling with ongoing nutritional monitoring on cancer cachexia severity in women with advanced breast cancer. Cancer cachexia is a multifactorial syndrome characterized by muscle wasting, anorexia, inflammation, and reduced functional status, significantly impairing quality of life and treatment tolerance. Despite its clinical relevance, targeted interventions for cachexia remain underutilized in routine oncology care.

The study is designed as a two-arm, parallel-group trial comparing standard oncological care alone with standard care plus a tailored nutritional intervention. The intervention is structured to address energy and protein intake requirements using individualized plans developed by a clinical dietitian. It incorporates scheduled nutritional counseling sessions, structured adherence monitoring through food logs and checklists, and reinforcement strategies including light physical activity promotion and psychosocial support.

To ensure methodological rigor, the study employs block-stratified randomization with concealed allocation using opaque, sealed envelopes. While blinding of participants and care providers is not feasible due to the nature of the intervention, outcome assessors and data analysts will be blinded to minimize bias. The primary outcome-change in cachexia severity over six months-will be evaluated using a validated multidimensional tool that captures clinical, functional, and patient-reported parameters.

Data will be entered into a secure, password-protected database with built-in quality control processes, including double data entry and discrepancy checks. Missing data will be handled using multiple imputation under the assumption of missing at random. Statistical analyses will be conducted on an intention-to-treat basis, with appropriate covariate adjustment and effect size reporting.

This trial is expected to provide practical evidence on the feasibility and effectiveness of structured, individualized nutritional interventions as part of supportive oncology care in resource-constrained settings.

Inclusion Criteria:

1. Female patients aged 20 to 60 years
2. Histologically confirmed advanced breast cancer
3. Documented unintentional weight loss of ≥5% over the past 6 months
4. Hemoglobin level <12 g/dL or average daily energy intake <1500 kcal/day
5. Ability to provide written and verbal informed consent

Exclusion Criteria:

1. Malnutrition due to non-cancer causes (e.g., chronic starvation, eating disorders)
2. Presence of chronic gastrointestinal or endocrine disorders affecting nutritional status (e.g., Crohn's disease, Cushing's syndrome)
3. Current pregnancy or lactation
4. Concurrent diagnosis of another malignancy
5. Any condition that, in the opinion of the investigator, may interfere with study participation or outcomes (e.g., severe psychiatric illness, cognitive impairment)

Yes, individual participant data (IPD) will be shared. The following data will be shared: de-identified demographic data, baseline characteristics, outcome data, and adverse events. Data will be available beginning 6 months after publication and will be shared for a period of 3 years. Data will be accessible to researchers with a methodologically sound proposal via a secure data-sharing platform, upon request to the principal investigator.

IPD will be available starting 6 months after publication of the primary results and will remain accessible for 3 years.

IPD will be available to researchers with a methodologically sound proposal. Requests must be submitted in writing to the principal investigator and must include a study protocol and ethical approval. Data will be provided through a secure data access system upon signing a data-sharing agreement.