Mortality foresight of 7.TNM and 8.TNM stagings with additional criteria in lung carcinoma

ABSTRACT Introduction: The staging of lung cancer provides important informations on prognosis and treatment planning. In the 8th TNM staging, different from the 7th TNM staging, a separate T is defined for each centimetre up to 5 cm (T1a-c ve T2a-b). The main changes in T part of 8th TNM staging are atelectasis independant of being partial or total that stages as T2, tumour invasion to the diaphragm as T4 and exclusion of tumour distance from main carina. In M staging, the number of involved extrathoracic organs and metastasis is added. The objectives of this study are to reveal whether the 8th TNM staging is superior to the 7th TNM staging in newly diagnosed lung cancer cases in defining the prognosis and to determine the additional criteria that may contribute to staging. Materials and Method: The files of 769 patients diagnosed as lung cancer in the Medical Faculty Hospital of the Ege University between 2014-2016 were investigated retrospectively. The demographic data, the histopathological types of the lung cancer, staging with 7th TNM criteria, staging with 8th TNM criteria, the sides of the primary tumours , the dimensions of the involved lymph nodes, number of metastatic organs, the sizes of the metastasis, the PET/BT data of the primary mass, lymph nodes and metastatic foci, the Ki-67 percentages, the presence of mutation analysis, the dates of diagnosis, and the dates of death of the patients included in the study were recorded. The last mortality evaluation was made on 04.11.2017 and the survival analyses were based on the follow-up until this date. Results: Of the 412 patients included in the study, 349 were male (85%) and 63 (15%) were female and the average age was determined as 63±10. The average age was calculated as 59±12.4 in females and as 64±9.3 in males. The younger diagnosis age in females was statistically significant (p<0.001). The survival rate in patients at the age of 65 or more was found higher (p<0,001). (p=0,002) The presence of atelectasis decreased survival when compared with patients without atelectasis. The survival rate was found shorter in patients with total atelectasis when compared to those with partial or no atelectasis. There was no survival difference in patients with paritial and no atelectasis (p=0,125). Although endobronchial spread decreased the survival rate (p>0.001), it was observed that when the distance to the carina was <20 mm, this effect was more obvious, as assessed by bronchocopy (p=0.002). When the T stage of the patients were examined with respect to the 7th TNM and the 8th TNM, there was no significant difference between the survival rates between cT1b-cT2a in the 7th TNM and between cT1c-cT2a and cT3-cT4 in the 8th TNM. According to the 7th TNM staging, a difference was observed between cM1a-M1b in the clinical M staging (p<0.001), and there was a significant difference was observed between cM1a-cM1b and cM1b-cM1c in the 8th TNM staging (p=0.006, p=0.013). Bone in 92 patients and surrenal glands in 55 patients were found as most frequent sides of metastasis. The survival rate of patients with bone metastasis was found different shorter when compared to those with other sides metastasis. In pathological TNM staging, there was no significant difference in survival between consecutive stages in T and M. In the 7th TNM and the 8th TNM stages, there was a significant difference between pM0 and pM1 (p<0.001). There was no difference between the other consecutive M stages. It was observed that survival was obviously worse in patients with primary tumour SUVmax values ≥10 (<0,001). The bone, liver, surrenal average, where metastasis was the most frequent, was examined with respect to SUVmax values. It was determined that the prognosis of the patients with involvements higher than the average was worse. Conclusion: It was observed that the distance to the carina, atelectasis type and tumour size, excluded from the TNM affected survival. Atelectasis and the distance to the carina staged in the 7th TNM staging system and the size of the primary tumour staged in the 8th TNM staging increased mortality foresight. In patients for whom the N stage is defined according to both staging, the effect of LN involvement locality on survival can be observed. It is observed that bone metastasis has an adverse effect on survival; however, this observation must be supported with further studies. It was observed that when SUVmax involvement is above the average in primary tumour, liver, bone and surrenal metastasis worsened the prognosis. It is maintained that PET/BT findings are added to TNM staging. It is planned that the follow-up of the patients included in the study to strengthen the results of the survival analyses. It is appropriate that the results are supported by new studies. Key Words: Lung cancer, 7th TNM, 8th TNM, Staging, PET/BT, SUV