{'fraction_non_alphanumeric': 0.033563218390804596, 'fraction_numerical': 0.030344827586206897, 'mean_word_length': 5.044444444444444, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Clinical characterization of node-negative non-small cell lung cancer: Results of a prospective investigation.

7218 Background: 20 to 30% of clinical stage IA non-small cell lung cancer cases were revealed to be node-positive by pathologic examination of resected specimens. In this prospective study, the clinical features of a truly node-negative population were prospectively investigated to search for candidates of a lesser resection or of a stereotactic radiotherapy.


METHODS
The clinical data and radiographic features of high-resolution computed tomography (HR-CT) were registered before operation in 169 clinical stage IA lung cancer patients, who were scheduled to undergo a standard lobectomy and systemic mediastinal node dissection. The nodal metastasis was pathologically defined, while the clinical factors associated with the presence of the nodal metastasis were evaluated.


RESULTS
In 130 evaluable cases, 16 of 114 adenocarcinoma and 3 of 16 other NSCLC were node-positive. Among all parameters, positivity of the serum carcinoembryonic antigen (CEA) was the only factor significantly associated with nodal metastasis (p = 0.0074). When we focused on adenocarcinomas, the serum CEA, retraction sign and intratumoral air-space on HR-CT were suggested to be predictive factors for lymph node metastasis with hazard ratios of 12.44 (p = 0.0003), 6.53 (p = 0.0533) and 0.17 (0.0073), respectively. In combination with the radiologic features of HR-CT imaging, none of 18 CEA-negative/retraction-negative cases and 3 of 65 CEA-negative/air-space positive cases showed nodal metastasis, in which the incidence of nodal metastasis was significantly lower than the counterparts with respective p-values of 0.0015 and 0.037. The tumor size and the proportion of ground glass attenuation were not associated with the incidence of nodal metastasis.


CONCLUSIONS
The serum CEA and HR-CT features thus allowed us to identify node-negative lung adenocarcinomas. In clinical stage IA adenocarcinoma cases, a standard operation should be considered when positive serum CEA and/or retraction sign on HRCT is noticed. No significant financial relationships to disclose.