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【medical-news】肿瘤大小：肺癌存活率的重要预测
September 4, 2008 — Among patients with resected non–small-cell lung carcinoma (NSCLC), tumors over 15 mm in diameter are associated with an increased risk for mediastinal metastases and with shorter 5-year survival. This was found to be the case in all tumor, node, and metastasis (TNM) system categories, researchers report in the September issue of the Journal of Thoracic Oncology.
"We have shown that inside the T1, tumors below 15 mm in diameter have a different behavior regarding survival than tumors over 15 mm," lead author Silvia Quadrelli, MD, a staff physician at Hospital Británico de Buenos Aires, in Argentina, told Medscape Oncology in an interview. "In practical terms, it means that we are putting patients together who are essentially different. And it also means that our estimates of survival may be wrong. The current system of classification doesn't clearly differentiate between these groups.
"In our study, we found that patients with tumors below 15 mm had a 5-year survival of 95%," she added. "In the other group, the patients had the same stage and the same pN0, but their tumors were larger than 15 mm, and their 5-year survival was only 65%. That is a great deal of difference."
The TNM system has been internationally recognized as the standard for staging extension and has also undergone repeated revision during the past 30 years. The last revision was in 2002 and has remained unchanged since then. Although the TNM stage remains the most important prognostic factor for patients with resected NSCLC, research during the past few years has begun to more closely examine the influence of tumor size, even within the same stage.
We have shown that size matters.
The increasing availability of more accurate imaging methods has allowed for the detection of very small lesions, but tumor size is a factor that has not changed since the initial staging system of 1973, and the cutoff value of 3 cm is still in use to discriminate between T1 and T2 tumors, the authors note. There has been growing controversy over the impact of tumor size by itself, as an independent variable unrelated to stage. Subdividing stage I in terms of tumor size has been considered as a result of these discussions.
"We have shown that size matters," said Dr. Quadrelli, "And we may need to redefine the T factor. Discovering very small tumors, even smaller than those discussed in our paper, may perhaps be more important."
Impact of Tumor Size
In this study, Dr. Quadrelli and colleagues evaluated the impact of tumor size on survival rates among 400 patients with NSCLC who underwent pulmonary resection with a curative intention. The median follow-up time was 44.7 months.
Adenocarcinoma was the most common type of malignancy, observed in 61.2% (n=245) of patients, followed by squamous cell, noted in 92 patients (23%). In 85.2% of the cohort (n=341), surgery was considered a complete resection. The majority of patients in the study were either clinical stage IA or IB (70.8%), and during the follow-up period, recurrences were reported in 137 patients, with distant recurrence being the most common (99 patients, 72.3%).
The researchers found that in an analysis looking at pathologic stage, the 5-year survival for patients at stage IA was 85.9%. However, when patients with neoplastic hilar, mediastinal, or distant metastases (pN0M0) were eliminated from the analysis and it included only those who had undergone a complete resection, the difference in survival was significantly altered in terms of tumor size. Patients with pN0 tumors that were smaller that 15 mm in diameter had a 5-year survival rate of 95%, compared with 65% among patients with tumors larger than 16 mm.
Upon multivariate analysis, tumor size and the T factor had independent prognostic effects on overall survival, and univariate analysis for pN0 patients showed that factors such as age, sex, location of tumor, or adenocarcinoma histology did not significantly affect survival. However, survival was negatively affected when the T factor was higher and the tumor size was larger.
"Our data suggest that tumors over 15 mm are associated with an increased risk of mediastinal metastases and with shorter 5-year survival in all TNM categories," conclude the researchers. "Current TNM categories are not sufficiently discriminatory, and the T factor requires to be reevaluated in further revisions of the TNM classification."
J Thorac Oncol. 2008;3:989-993. 认领此文编译，48小时未交稿，其他战友可自由认领。
Tumor Size Important Indicator for Survival in Lung Cancer
肿瘤大小是肺癌患者生存期的重要指标
September 4, 2008 — Among patients with resected non–small-cell lung carcinoma (NSCLC), tumors over 15 mm in diameter are associated with an increased risk for mediastinal metastases and with shorter 5-year survival. This was found to be the case in all tumor, node, and metastasis (TNM) system categories, researchers report in the September issue of the Journal of Thoracic Oncology.
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作者:admin@医学,生命科学 2011-06-07 05:11
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