M01-02: Treatment for the screen-detected lung cancer: characteristics and outcome

Abstract

Owing to the advent of refined chest CT images with higher resolution and CT screening programs, smaller lung cancers are being discovered in asymptomatic patients. Most of them are more often found on a low-dose CT images, and they tend to have characteristic appearance on high-resolution CT scan as ground glass opacity (GGO), a focal intermediate/mild increase in the CT density. Of course, the screening program is still picking up the more solid tumors with/without lymph node involvement, the percentage of GGO or GGO-like lesions is obviously increased in low-dose CT screening era. These GGO tumors are pathologically characterized by the morphology of non-/minimally invasive form of well-differentiated adenocarcinoma termed as bronchioloalveolar carcinoma (BAC) of the non-mucinous type. The superb prognosis of these GGO-BAC tumors is being recognized in the surgical community. Although the gold standard operation for peripheral lung cancer has been lobectomy with lymph node sampling/dissection, the revision is thought to be necessary, especially for these screen-detected GGO-BAC tumors. The possibility of limited resection such as segmentectomy/wedge resection seems to be realistic. Enough number of institutional reports describing the equivalent surgical outcome by limited resection have been accumulated. Therefore, the randomized phase III trial between lobectomy and limited resection is being planned both in US and Japan in a non-inferiority design setting. The results of these studies might be applied in the management of screen-detected, small-sized tumors in the near future.