Predictive Factors For Pathological Complete Response In Carcinoma Thoracic Esophagus.

Introduction: Neoadjuvant chemoradiation followed by surgery has evolved as the Positron Emission Tomography-Computed Tomography (PET-CT) is increasingly being used for radiological response assessment and prediction of pathological response. Pathological complete response (pCR) to neoadjuvant therapy has been shown in various trials to be a surrogate marker for locoregional control and survival. Aim: To evaluate the predictive and prognostic factors for pathological complete response in carcinoma esophagus Methods: All consecutive patients of carcinoma thoracic esophagus attending the Radiation Oncology OPD between December 2013 and December 2014 for preoperative chemoradaiation followed by surgery; were selected for the study. They were prospectively analysed for basic socio-demographic data, patient and treatment related characteristics, response to therapy and survival parameters. All included patients underwent preoperative chemoradiation followed by radiological response evaluation with PET-CT followed by surgical resection. A total disappearance of all target lesions was taken as complete radiological response and a reduction of at least 30% in the maximum standardized uptake (SUVmax) value in the target lesions was taken as partial radiological response (Percist Version 1.0). Subsequently pathological response was assessed with histopathological examination using CAP criteria. Multiple univariate and multivariate analyses were done to establish significant factors associated with complete pathological response. Results: Fifty consecutive patients of carcinoma thoracic esophagus were prospectively recruited and analysed. More than half (52%) were females; with a median age at diagnosis of 55 years (Range: 35 - 71 yrs); mean tumour length on PET-CT was 5.9 cm and mid thoracic esophagus was the most common site of involvement, accounting for 68% of all cases. Squamous Cell Carcinoma was the most common histology accounting for 96% of all cases. Radiological complete response and pathological complete response were seen in 49% and 31% of all patients respectively. On univariate analysis gender (p = 0.02), ECOG (Eastern Cooperative Oncology Group) performance status at presentation, percentage drop in SUVmax (p = 0.01), chemotherapy regimen used and radiological complete response (p = 0.02) emerged as statistically significant factors of pathological complete response. However on multivariate analysis none of the factors reached significant values. Conclusion: One of the significant markers of complete pathological response is radiological response which is achieved in a fair number of patients. There is a significant association between the radiological and pathological response. Overall, complete pathological response can be predicted reasonably well by using PET-CT. Further research with bigger datasets is required to establish the association and institute PETCT as an integral component of management protocol in Carcinoma Esophagus. [ABSTRACT FROM AUTHOR]