Title: PD4-1-1: The impact of systemic therapy versus surgery on outcomes in multifocal bronchioloalveolar carcinoma
Abstract: Bronchioloalveolar carcinoma (BAC) is a subtype of non-small cell lung cancer (NSCLC) with distinct clinical features, tumor biology, response to therapy and prognosis. The disease is commonly multifocal, presenting as numerous nodules that are either confined to a single lobe or distributed among several lobes of the lung. Primary management of multifocal BAC remains controversial and may include close surveillance, surgical resection and/or systemic therapy. Knowledge of current practice patterns and outcomes may help to define an optimal treatment modality. All patients diagnosed with pure BAC or NSCLC with BAC features at a major cancer center between January 2001 and December 2005 were identified from the hospital cancer registry and central pathology database. Corresponding medical records were reviewed for demographic parameters, disease characteristics, treatment modality and clinical outcomes. In total, 109 patients with pure BAC or NSCLC with BAC features were identified. Twenty-four patients were excluded due to alternate diagnoses, early recurrent or progressive disease, or transfer of care to other facilities, leaving 85 patients who were eligible for study. The mean age at diagnosis was 64.2 years, 54 (63.5%) were females, and 56 (65.9%) were smokers. At diagnosis, 22 (25.9%) were stage IA to IIIA and 63 (74.1%) were stage IIIB or IV. Of the 63 patients with multifocal BAC, 15 (23.8%) had disease confined to one lobe while 48 (76.2%) had multiple lobes involved. The primary treatment modality for multifocal disease included surgical resection in 49 (77.8%), systemic therapy in 9 (14.2%) and observation in 5 (8.0%) cases. Among the 9 patients treated with systemic therapy, 6 had disease in 3 or more lobes, 5 received cytotoxic chemotherapy and 4 received epidermal growth factor receptor (EGFR) inhibitors. Median follow-up was 25.2 months. Among the 49 patients who underwent resection, only 19 (38.8%) developed a recurrence, most commonly in the lung (16) and brain (3). Recurrent or progressive disease occurred in 7/9 patients in the systemic therapy group and 1/5 patients in the observation group. Surgery and observation continue to be reasonable treatment options for selected patients with multifocal BAC. The apparent lack of benefit of systemic therapy in this series may reflect selection bias in referral patterns and treatment choice where only those with more aggressive disease (3 or more lobes involved) received cytotoxic agents or EGFR inhibitors. The role of systemic therapy in multifocal BAC deserves further prospective evaluation.