Presentation (CTI)

OBJECTIVES: Lung cancer is frequently diagnosed at advanced stages. Early detection significantly improves outcomes. This study investigates the characteristics and diagnostic pathways of patients with small nodules (SN) versus large nodules (LN) to identify factors that could improve early diagnosis.
METHODS: A retrospective analysis was conducted using the Japanese Medical Data Vision (MDV) from 2008 to 2023. Patients with T1a or T1b lung cancer were classified as SN, while those with more advanced T stages were categorized as LN. Patients without any diagnostic procedures before cancer confirmation, those with TX, T0, or Tis stages, and those with incomplete records were excluded. Patient characteristics, biopsy and imaging rate, and time to cancer confirmation were compared between SN and LN groups. Logistic regression was used to identified factors influencing biopsy decisions.
RESULTS: The cohort included 11,989 SN and 31,278 LN patients. Only 20.2% of SN and 20.7% of LN patients received biopsy. SN patients were younger, more likely to be female, less likely to smoke, and had higher obesity rates. Among SN patients who received biopsies, 37.7% had multiple biopsies and was higher than LN patients (29.2%, p <.001). SN patients experienced longer time to cancer confirmation - 90 days longer from first procedure to confirmation, and 45 days longer from first suspected diagnosis to confirmation (p <.001). Higher imaging frequency (OR: 1.96 [1.86, 2.06]), COPD (OR: 1.88 [1.75, 2.02]), and hypertension (OR: 1.58 [1.47, 1.70]) increased the likelihood of receiving biopsies before cancer diagnosis for both groups. Diabetes (OR: 1.48 [1.35, 1.61]) and obesity (OR: 1.19 [1.10, 1.28]) influenced biopsy decisions in LN patients, but not in SN patients.
CONCLUSIONS: This study highlights the diagnostic challenges of SN lung cancer in Japan and identifies factors for early diagnosis. Addressing low biopsy rates and improving biopsy technology may enhance early detection and patient outcomes.