How many pathological T1N0M0 non-small cell lung cancers can be completely resected in one segment? Special reference to high-resolution computed tomography findings

Purpose: Although segmentectomy is attempted for small non-small cell lung cancer (NSCLC) tumors, no reports have so far described how many of these tumors can be candidates for a successful resection by single segmentectomy. Methods: In all, 135 patients with peripheral p-T1N0M0 NSCLC were examined. The tumors were classified into five groups divided by every 0.5-cm increase in size. Tumor locations were classified into two groups - limited to within one segment and extended beyond one segment - based on the identification of whether pulmonary vessels and the bronchi were involved in the tumors on high-resolution computed tomography. Differences in the proportion of tumors limited within one segment between tumors smaller and larger than each class of tumor size were assessed. Results: The tumor sizes were 0-1.0 cm in 8 tumors, 1.1-1.5 cm in 27, 1.6-2.0 cm in 35, 2.1-2.5 cm in 34, and 2.6-3.0 cm in 31 tumors. Of these 135 tumors, 92 (65%) were limited to one segment, whereas 48 (35%) had extended beyond one segment. When the tumor size was less than 30 mm, the proportion of tumor limited within one segment did not show any significant difference depending on the size of the tumor. Conclusions: More than one-third of p-T1N0M0 NSCLC tumors extended beyond one segment, irrespective of size. It is therefore noteworthy that resection of up to two segments or lobectomy should be undertaken for prevention of local recurrence in patients with p-T1N0M0 peripheral NSCLC.