Burden and determinants of anemia at cancer diagnosis among treatment naive patients with solid tumors in a South Indian cohort

Baseline anemia is a common and clinically important comorbidity in patients with cancer that may adversely affect functional status, treatment preparedness, and supportive care needs. However, its epidemiological burden and associated factors among treatment-naïve patients with solid tumors in low- and middle-income countries (LMICs) remain insufficiently characterized. This cross-sectional study enrolled 401 consecutive treatment-naïve patients with histologically confirmed solid tumors at a tertiary regional cancer center in North Coastal Andhra Pradesh, India, between September 2024 and August 2025. Anemia was defined according to World Health Organization criteria and graded using Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. Sociodemographic, clinicopathological, and anthropometric variables were evaluated. Independent determinants of anemia were identified using multivariable logistic regression, and district-level anemia prevalence was geographically mapped. Baseline anemia was present in 66.8% (95% CI: 62.2–71.4%) of patients. The prevalence was significantly higher among females (72.8% vs. 57.1%), patients with advanced-stage disease, and those with gastrointestinal and gynecological malignancies (all P < 0.05). Anemic patients had significantly lower body mass index and mid-upper arm circumference (MUAC), both of which correlated positively with hemoglobin concentration. After multivariable adjustment, ECOG performance status 2 (aOR = 3.50), and 3 (aOR = 4.08), together with advanced-stage disease (aOR = 1.86) remained independently associated with anemia, whereas breast cancer was associated with significantly lower odds of anemia than gynecological malignancies (aOR = 0.32). Geographic mapping revealed regional variation in baseline anemia prevalence across the study districts. Baseline anemia affects approximately two-thirds of treatment-naïve patients with solid tumors in this South Indian cohort. Advanced disease stage and poorer functional status were the principal independent determinants of anemia, while nutritional compromise was closely associated with anemia burden. These findings support incorporating routine hemoglobin assessment and nutritional evaluation into pre-treatment oncology care and provide evidence to inform supportive care strategies in resource-limited settings.