Background: During the period that randomized clinical trials were establishing the role of adjuvant therapy in tumors larger than 5 cm without lymph-node invasion, which shifted from stage IB (6th TNM) to stage II (7th TNM), we derived the rate of shifted patients in our series and analyzed the relationship between specific patient- and tumor- characteristics, and clinical outcome, to identify putative prognostic factors.
Methods: We retrospectively collected data (age, sex, smoking status, type of surgery grading, and histological type) from 467 patients who underwent radical surgery for primary 6th TNM-T2N0 non-small cell lung cancer patients between 1998 and 2009 at our institute. Categorical variables were cross-tabulated by tumor staging according to the 7th TNM edition, and they were tested both for association with stage and survival.
Results: One hundred and eighteen patients shifted to stage II, mainly older patients and patients with a sarcomatoid or a poorly differentiated carcinoma. Median overall survival time was significantly different across stages. Among the factors investigated, only the tumor dimension resulted in being statistically significant in multivariate analysis.
Conclusions: Nearly a quarter of patients shifted from stage I (6th TNM) to stage II (7th TNM), raising a major need for information on the effects of adjuvant chemotherapy in this group of patients. Our findings suggest that randomized clinical trials aimed at addressing this topic should consider only tumor dimensions as principal selection criteria.