Update on Therapeutic Strategy in Lung Carcinoids

An estimated 25% to 30% of all neuroendocrine tumors (NETs) have their origin in the bronchial tree and into the lungs. Although lung NETs account for less than 1% of all pulmonary malignancies, the incidence of these neoplasms has risen precipitously since the mid 1970s. Currently, according to the 2004 World Health Organization categorization, these tumors are separated into 4 subtypes characterized by increasing biologic aggressiveness: low-grade typical carcinoid (TC), intermediate-grade atypical carcinoid (AC), high-grade large-cell neuroendocrine carcinoma (LCNEC) and small-cell carcinoma (SCLC). Surgery is the treatment of choice for typical and atypical carcinoid lung NETs with loco-regional disease. At diagnosis up to 64% of patients with atypical carcinoid lung NETs present with lymph node metastases, and 5-year survival ranges from 61% to 88%. In contrast, lymph node metastases are present in fewer than 15% of typical carcinoid lung NETs, and 5-year survival exceeds 90%. To date, there is no recognized standard of treatment for advanced carcinoid lung NETs. In recent years only two trials reported intriguing results regarding lung NETs: a phase 2 retrospective study of dacarbazine derivative temozolomide and the phase 3, RADIANT-2 trial in advanced NETs. Successful management requires a multidisciplinary team management. This review is restricted to typical/atypical NETs.