S Cascinu1, D Poli2, A Zaniboni3, S Lonardi4, R Labianca5, A Sobrero6, G Rosati7, M Di Bartolomeo8, M Scartozzi9, V Zagonel4, N Pella10, M Banzi11, V Torri2. 1. Modena Cancer Center, Università di Modena e Reggio Emilia, Italy. Electronic address: cascinu@yahoo.com. 2. Laboratory of Methodology for Clinical Research, IRCCS-Istituto di Ricerche Farmacologiche Mario Negri, Milano, Italy. 3. Medical Oncology Unit, Fondazione Poliambulanza, Brescia, Italy. 4. Medical Oncology 1, Istituto Oncologico Veneto (IOV)-IRCCS, Padova, Italy. 5. Cancer Center, Ospedale Papa Giovanni XXIII, Bergamo, Italy. 6. Medical Oncology Unit, IRCCS San Martino-IST, Genova, Italy. 7. Medical Oncology Unit, Ospedale San Carlo, Potenza, Italy. 8. Medical Oncology Unit, Fondazione Istituto Nazionale Tumori-IRCCS, Milano, Italy. 9. Medical Oncology Unit, University Hospital and University of Cagliari, Cagliari, Italy. 10. Medical Oncology Unit, Azienda Ospedaliero Universitaria Santa Maria della Misericordia, Udine, Italy. 11. Medical Oncology Unit, Arcispedale Santa Maria Nuova-IRCCS, Reggio Emilia, Italy.
Abstract
PURPOSE: Because the role of the primary tumour location in the adjuvant setting has not been clearly established in colon cancer, we analysed the clinical outcome according to the primary tumour location from three Italian trials assessing adjuvant therapy in colon cancer. PATIENTS AND METHODS: Overall survival (OS) and disease-free survival (DFS) were assessed globally and in each trial, according to right-sided, transverse and left-sided primary colon cancer. Analysis was planned to provide overall and stage-specific results. RESULTS: Individual data of 5239 patients were included in this analysis. The right-sided tumours were 1540 (29%), tumours originating in the transverse were 815 (16%) and left-sided tumours were 2884 (55%). At the multivariate analysis, DFS findings from the comparison of the right-sided versus left-sided tumours (hazard ratio [HR] = 1.00; 95% confidence interval [CI] = 0.89-1.14) were not statistically associated with clinical outcomes in the overall population. On the contrary, OS findings, from the comparison of the right-sided versus left-sided tumours, were significantly associated with outcomes (HR = 1.20; 95% CI = 1.04-1.39). In stage II patients, there was no difference in terms of DFS and OS among the three different tumour locations, whereas in stage III patients, the left-sided tumours showed an improved prognosis in terms of OS (HR: 1.36 95% CI = 1.14-1.62, p < 0.001). CONCLUSION: This is the largest analysis demonstrating a prognostic effect of the tumour location on patients with colon cancer receiving adjuvant chemotherapy. Nevertheless, the effect is limited to OS in stage III colon cancer. In stage II tumours, the primary location has a lesser impact. The transverse tumours should be prognostically considered in between the right-sided and left-sided tumours.
PURPOSE: Because the role of the primary tumour location in the adjuvant setting has not been clearly established in colon cancer, we analysed the clinical outcome according to the primary tumour location from three Italian trials assessing adjuvant therapy in colon cancer. PATIENTS AND METHODS: Overall survival (OS) and disease-free survival (DFS) were assessed globally and in each trial, according to right-sided, transverse and left-sided primary colon cancer. Analysis was planned to provide overall and stage-specific results. RESULTS: Individual data of 5239 patients were included in this analysis. The right-sided tumours were 1540 (29%), tumours originating in the transverse were 815 (16%) and left-sided tumours were 2884 (55%). At the multivariate analysis, DFS findings from the comparison of the right-sided versus left-sided tumours (hazard ratio [HR] = 1.00; 95% confidence interval [CI] = 0.89-1.14) were not statistically associated with clinical outcomes in the overall population. On the contrary, OS findings, from the comparison of the right-sided versus left-sided tumours, were significantly associated with outcomes (HR = 1.20; 95% CI = 1.04-1.39). In stage II patients, there was no difference in terms of DFS and OS among the three different tumour locations, whereas in stage III patients, the left-sided tumours showed an improved prognosis in terms of OS (HR: 1.36 95% CI = 1.14-1.62, p < 0.001). CONCLUSION: This is the largest analysis demonstrating a prognostic effect of the tumour location on patients with colon cancer receiving adjuvant chemotherapy. Nevertheless, the effect is limited to OS in stage III colon cancer. In stage II tumours, the primary location has a lesser impact. The transverse tumours should be prognostically considered in between the right-sided and left-sided tumours.