[Clinical features and treatment outcome of multiple primary lung cancer patients with different imaging performance].

Objective: To analyze the clinical characteristics and follow up record of patients with synchronous multiple lung cancers (SMLC).

Methods: The medical records of 1 868 lung cancer patients who underwent surgical treatments From January 2007 to December 2014 were reviewed, in which 103 patients were diagnosed SMLC by Martini and American College of Chest Physicians modified guideline. The average age was 60.5 years, including 34 male and 69 female patients. According to consolidation/tumor ratio (CTR) on thin-section computed tomography, 103 cases were classified into three groups: group A (multiple ground-glass opacities, CTR ≤ 50%), group B (with one solid dominant nodules, CTR > 50%), group C (with two solid dominant nodules). The surgical procedure was determined according to CT findings and respiratory function. The Kaplan-Meier method was used to analyze the duration of recurrence-free survival (RFS) and over-all survival (OS), and differences were assessed using the Log-rank test. Multivariate analysis using the Cox proportional hazards models was used to assess the potential independent effects on RFS or OS.

Results: There were 38 patients in group A (36.9%), 40 patients in group B (38.8%) and 25 patients (24.3%) in group C. More female (73.7% vs. 48.0%, χ² = 4.291, P = 0.038), less smoker (21.1% vs. 44.0%, 2 = 3.770, P = 0.052), younger (56.2 years old vs. 65.9 years old, t = -4.172, P = 0.000) and less tumor size (1.24 cm vs. 2.31 cm, t = -4.573, P = 0.000) patients in group A than in group C. The 3, 5-year RFS were 80.3% and 64.9% for all patients, respectively. The 3, 5-year OS were 87.3% and 68.6% for all patients, respectively. The 3, 5-year RFS were 100% and 100% in group A, 77.7% and 51.8% in group B, 59.6% and 44.7% in group C (P = 0.029). No significance were found in OS between the three groups (P = 0.214). Multivariate Cox analysis demonstrated that size of dominant nodule larger than 2 cm (HR = 4.475, 95% CI: 1.138 to 17.604, P = 0.032) is associated with poor prognosis, whereas postoperative chemotherapy did not affect RFS.

Conclusions: Multifocal ground-glass opacities and multiple solid lung cancers are different in nature. RFS of patients with SMLC is strongly affected tumor size. Surgical resection is effective and should be performed specifically to patients.