What is the appropriate operative strategy for radiologically solid tumours in subcentimetre lung cancer patients?†

Abstract

There might be a possibility of lymph node metastasis despite subcentimetre lung cancer, especially for radiological pure-solid nodules that show a high SUVmax. If limited surgery is indicated for solid subcentimetre lung cancer, a thorough intraoperative evaluation of lymph nodes is needed to prevent loco-regional failure.

Controversies on lung cancers manifesting as part-solid nodules

“…Time from the initial identification of the PSN to diagnosis and resection was given in only 1 of the 27 studies [57]. Tumour size was an inclusion criterion in all but two articles [56, 61]. The year of publication may be important, as CT scanner and surgical technologies may have changed over time, but no statistically significant relationship was found when we examined the association between year of publication and survival outcomes; thus year of publication did not have an effect on lung cancer survival.…”

“…Frequency of LN involvement was reported in 19 of the 27 groups (1781 patients) [54, 58, 59, 61–64, 66, 67, 69–73, 77, 79, 81]. In 6 of the 19 groups, no LN metastases were found (450 patients), and in the remaining 13 groups, LN metastases ranged from 1%-33%.…”

“…OS was only reported by one of the two studies and it was 98% [64]. For the ten studies (1022 patients) that reported on rates for category PSN≥80% [58, 61, 62, 64, 67, 70, 71, 73, 75, 79] after excluding those that also had solid nodules, the median DFS was 85% in nine groups (992 patients) and median OS was 95% in seven groups (753 patients). The frequency of lymph node involvement was reported in nine of the ten groups (959 patients); four of the nine groups (339 patients) reported no lymph node metastases, and the remaining five groups (620 patients) reported lymph node metastases at rates ranging from 4%-17%.…”

“…For the 20 groups reporting on lung cancers manifesting as PSN<80%, the median DFS and OS rates were above 97%, whereas in the 27 groups with lung cancers manifesting as PSN≥80%, median rates were never above 86% − ten per cent below the rates for PSN<80%. As 6 of the 27 groups [61, 62, 70, 75, 77, 79] reporting on PSN≥80% included PSNs with very small solid components (as low as 1%) as well as solid nodules, these rates may be somewhat inaccurate because of these extreme inclusions. However, survival rates remained very high when articles that included NSNs and solid nodules were excluded, further corroborating our main finding that patients with lung cancers manifesting as PSN had very good survival, particularly when the solid component was less than 80% of the entire nodule diameter.…”

Neither Maximum Tumor Size nor Solid Component Size Is Prognostic in Part-Solid Lung Cancer: Impact of Tumor Size Should Be Applied Exclusively to Solid Lung Cancer

“…Based on the result of the pathoradiologic correlation in the Japan Clinical Oncology Group (JCOG) 0201 study [4,7], the radiologic criteria to distinguish noninvasive and invasive lung adenocarcinoma were defined as a CTR of 0.50 or less in c-T1a and c-T1b, and excellent prognosis were obtained for noninvasive adenocarcinomas [4,7]. However, radiologic solid lung cancers without a GGO component have been found to exhibit a more malignant behavior and have a poorer prognosis compared with part-solid lung cancers [9,10,[16][17][18]. Therefore, the significant differences between radiologic noninvasive and invasive lung cancers regarding overall survival in the prospective JCOG 0201 study may be strongly related to the presence of radiologic solid lung cancer without a GGO component in the invasive population.…”