Background: Pre-operative chemo-radiotherapy (CT-RT) produces a high rate of response in rectal cancer patients (pts). Several evidences suggests that using 2 drugs correlates with best responses and that complete pathologic response (cPR) induces prolonged survival. The aim of the present analysis was the evaluation of the effect of some biologic characteristics of the primary tumor on PR, as scored according to Tumor Regression Grade (TRG) scale. Methods: 45 pts, enrolled in a phase II trial, were treated with 2 cycles of CAP-OX concomitantly with pelvic conformal radiotherapy (45 Gy). EGFR, p53, PARP, XRCC, VEGFR and TS expression was determined by immunohistochemistry on rectal biopsies obtained prior CT-RT initiation, and scored as percentage of positive cells. The Spearman’s correlation test, t-test and logistic regression analysis were used to explore the correlation between these biological factors and the TRG (SPSS software). Biological factors expression was considered as a continuous variable. TRG was both considered as 4 categories and coded as TRG1 (cPR) vs TRG >=2. Results: Among the 42 operated pts, cPR (TRG-1) was observed in 10 (23.8%); TRG-2 in 18 (42.9%); TRG-3 in 11 (26.2%); TRG-4 in 3 pts (7.1%). Paraffin embedded biConclusions: A statistically significant inverse association was observed between TRG and TS expression; a weak correlation was suggested between cPR and low EGFR, VEGFR and PARP expression. Neither gender nor age significantly affected cPR.opsies from primary tumor were available for all pts.
Predictive factors of response to neoadjuvant chemoradiotherapy in rectal cancer patirnts.
PEPE, Stefano
2008-01-01
Abstract
Background: Pre-operative chemo-radiotherapy (CT-RT) produces a high rate of response in rectal cancer patients (pts). Several evidences suggests that using 2 drugs correlates with best responses and that complete pathologic response (cPR) induces prolonged survival. The aim of the present analysis was the evaluation of the effect of some biologic characteristics of the primary tumor on PR, as scored according to Tumor Regression Grade (TRG) scale. Methods: 45 pts, enrolled in a phase II trial, were treated with 2 cycles of CAP-OX concomitantly with pelvic conformal radiotherapy (45 Gy). EGFR, p53, PARP, XRCC, VEGFR and TS expression was determined by immunohistochemistry on rectal biopsies obtained prior CT-RT initiation, and scored as percentage of positive cells. The Spearman’s correlation test, t-test and logistic regression analysis were used to explore the correlation between these biological factors and the TRG (SPSS software). Biological factors expression was considered as a continuous variable. TRG was both considered as 4 categories and coded as TRG1 (cPR) vs TRG >=2. Results: Among the 42 operated pts, cPR (TRG-1) was observed in 10 (23.8%); TRG-2 in 18 (42.9%); TRG-3 in 11 (26.2%); TRG-4 in 3 pts (7.1%). Paraffin embedded biConclusions: A statistically significant inverse association was observed between TRG and TS expression; a weak correlation was suggested between cPR and low EGFR, VEGFR and PARP expression. Neither gender nor age significantly affected cPR.opsies from primary tumor were available for all pts.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
