Lung cancer is the main cause of cancer death worldwide. Even in early stages the cancer-specific survival is poor due to disease relapse. The TNM classification is the strongest prognostic tool. The 8th AJCC edition has changed the cutpoints for stage, leading to a “stage shift” or a “stage decrease”, mainly reflecting changes in the prognostic score attributed to the tumor diameter. We have reviewed a cohort of patients that were treated before the benefit of adjuvant chemotherapy was proved, in order to corroborate which of the two classifications represents better the risk of recurrence.
Retrospective analysis of a cohort of 182 patients with lung cancer treated with complete resection and no adyuvant chemotherapy, between 1999 and 2006. Evaluation criteria: overall survival.
1. Patient characteristics: median diagnostic age 68 years (39-86), 90% males, 48% current and 42% former smokers, 37% diagnosed of COPD. 2. Tumor characteristics:
- Histology: squamous 57%, adenocarcinoma 36%.
- Grade: 47% moderately differentiated, 33% undifferentiated. - Pathological staging by TNM edition.Table: 1351P
|7th edition n (%)||8th edition n (%)|
|IA||44 (24)||IA1||5 (2.7)|
|IB||69 (38)||IB||30 (16)|
|IIA||20 (11)||IIA||27 (15)|
|IIB||49 (26)||IIB||46 (25)|
3. median OS in our cohort of patients = 79 months (IC95% = 58-100) log Rank test p=NS me OS by pathological stage defined by 8th ed. AJCC: IA1 97 m (IC95% 37-158) IA2 108 m (IC95% 54-162) IA3 139 m (IC95% 13-266) IB 71 m (IC95% 45-96) IIA 35 m (IC95% 19-51) IIB 62 m (IC95% 34-90) IIIA 56 m (IC95% 0-141) 4. OS stage I vs II - by 7th edition: 93 vs 66 m, log Rank test, p = 0.016 - by 8th edition: 97 vs 70 m, log Rank test, p = 0.026 5. COPD as an adverse prognostic factor: meOS = 111 vs 55 months, log Rank test, p = 0.002
In our cohort of patients, the 8th edition of AJCC classification identifies better than the previous edition a group of patients with worse prognosis regarding to a higher size of the tumour and shiftening their pathological stage. Due to the small sample, we couldn’t prove a more accurate prognostic information for the new stage I categories in the 8th edition. COPD is confirmed in our serie as an adverse prognostic clinical factor.
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All authors have declared no conflicts of interest.