Low-dose spiral CT was superior to chest radiography in the screening and detection of peripheral lung cancer in high-risk individuals. Further large-scale studies are warranted, however, to clarify the efficacy and cost-effectiveness of low-dose spiral CT in a randomized, controlled population.

There is a need to work toward a mutual understanding and consensus between pathologists, clinicians, and researchers with the use of the term BAC versus adenocarcinoma. Future studies should make some attempt to quantitate these components and/or other features such as size of scar, size of invasive component, or pattern of invasion. Hopefully, this work will allow definition of a category of adenocarcinoma, mixed subtype with predominant BAC/minimal invasion and a favorable prognosis.

This study revealed the frequencies and periods of development from PGGNs and HGGNs into part-solid nodules. Invasive adenocarcinomas were diagnosed only among the part-solid nodules, corresponding to 1% of all 1229 SSNs.

Screening with low-dose helical CT has potential to improve screening efficacy in terms of reducing lung cancer mortality. An evaluation of efficacy using appropriate methods is urgently required.

Noguchi type A and B tumors may well be in situ carcinomas, and frozen-section examination was highly accurate. Neither local recurrence nor distant metastases have been found to date. Limited resection initial results appear promising.

The pGGOs of lung cancer nodules do not only increase in size or density, but may also decrease rapidly or slowly with the appearance of solid components. Close follow-up until the appearance of a solid component may be a valid option for the management of pGGO.

Because 10% of LPGGO lesions include invasive disease, patients with LPGGO should undergo pathologic examination for confirmation.

Single agent treatment with gefitinib is active in chemotherapy-naïve patients with advanced NSCLC, but produces unacceptably frequent ILD in the Japanese population.