Resumen de trabajo Aprobado en el Congreso Americano de Coloproctologia

Mi tesis de Doctorado en la Universidad de Sao Paulo, aprobado en el Congreso Americano de Coloproctologia, lo vamos a defender ahora en Mayo, en Hollywood Florida, junto a otros 2 trabajos del Servicio HC FMUSP

P356

COMPLETE PATHOLOGIC RESPONSE IS ASSOCIATED WITH LESS THAN

12 LYMPH NODES IN THE SPECIMEN OF PATIENTS WITH RECTAL CANCER

UNDERGOING NEOADJUVANT THERAPY FOLLOWED BY TOTAL

MESORECTAL EXCISION.

C. Nahas, S. Nahas, L. Bustamante, C. Marques, G. Cotti, U. Ribeiro Junior,

P. Hoff, I. Cecconello, R. Salles, R. Pinto and A. Imperiale Cancer Institute

of University of São Paulo Medical School, Sao Paulo, Brazil.

 

Purpose: To evaluate the possible factors associated with less than 12

lymph nodes (LN) harvest on patients with rectal cancer treated by neoadjuvant

chemoradiation (CRT) and total mesorectal excision (TME).

Methods: In one year period, 134 consecutive patients with low or mid

rectal cancer stage T2N0 under risk of sphincter resection, T3, T4, or +

underwent CRT followed by TME. Chemotherapy consisted of 5-FU and leucovorin

IV bolus on days 1 to 5 concomitant to radiation in weeks 1 and 5.

Total dose of pelvic radiation was 5040 Gys given in 28 sessions. All patients

were staged by digital rectal examination, proctoscopy, colonoscopy, CT of

abdomen and chest, and MRI of the pelvis. All patients had curative or

potentially curative TME. Specimens were subjected to histopathological

examination. Patients were divided in two groups: ≥12 and <12 LN

retrieved. The possible related variables affecting number of LN were analyzed:

gender, age (<60 versus >60 years old), presence of LN involvement,

tumor size, tumor location (low versus mid rectum), tumor stage (I versus II

versus III), length of specimen, sphincter preservation, surgical access (open

versus laparoscopy), and pathologic response to CRT.

Results: 95 patients met the inclusion criteria and could be treated, restaged

 and operated within the pre-established time intervals. Mean interval

time for re-staging was 8.3 (5.9-10.6) weeks. Mean LN harvest was 23.2

(3-67). 81 patients (85%) had ≥12 LN and 14 (15%) had <12 LN retrieved.

 There was no difference in tumor size, tumor stage, and length of specimen

between the two groups. Gender, age, presence of LN involvement, tumor

location, sphincter preservation, and surgical access showed no association

with number of LN retrieved. Only pathological complete response showed

a statistically significant association with <12 LN (p=0,002). Patients with

pT0N0 had 88% less chance of obtaining ≥12 LN.

Conclusions: Complete pathologic response is associated with <12 LN

 harvest. Thus, the number of lymph nodes should not be used as a surrogate

for oncologic adequacy of resection in patients with pathologic complete

response.