title: NEOADJUVANT THERAPY AND SURGERY FOR RECTAL CANCER. Comparative study between partial and complete pathological response.
abstract: BACKGROUND
  The approach of locally advanced extra-peritoneal rectal adenocarcinoma implies a treatment with neoadjuvant chemoradiotherapy associated with total mesorectal excision surgery. However, the tumors respond variably to this neoadjuvant therapy, and the mechanisms for response are not completely understood.
  
  
  OBJECTIVE
  Evaluate the variables related to the complete tumor response and the outcomes of patients who underwent surgery, comparing those with partial tumor regression and those with total remission of rectal lesion, at the pathological examination.
  
  
  METHODS
  Retrospective analysis of medical records of 212 patients operated between 2000 and 2010, in which 182 (85.9%) obtained partial remission at neoadjuvant therapy (Group 1) and 30 (14.1%), total remission (Group 2).
  
  
  RESULTS
  No difference was found between the groups in relation to gender, ethnicity, age, tumor distance from the anal verge, occurrence of metastases and synchronous lesions on preoperative staging, dose of radiotherapy and performed surgery. In Group 2, was verified high rate of complete remission when the time to surgery after neoadjuvant therapy was equal or less than 8 weeks (P=0.027), and a tendency of lower levels of pretreatment carcinoembryonic antigen (P=0.067). In pathological analysis, the Group 1 presented in relation to Group 2, more affected lymph nodes (average 1.9 and 0.5 respectively; P=0.003), more angiolymphatic (19.2% and 3.3%; P=0.032) and perineural involvement (15.4% and 0%; P=0.017) and greater number of lymph nodes examined (16.3 and 13.6; P=0.023). In the late follow-up, Group 1 also had lower overall survival than Group 2 (94.1 months and 136.4 months respectively; P=0.02) and disease-free survival (85.5 months and 134.6 months; P=0.004). There was no statistical difference between Group 2 and Group 1 in local recurrence (15% and 3.4%, respectively) and distant metastasis (28% and 13.8%, respectively).
  
  
  CONCLUSIONS
  In this study, the only factor associated with complete remission of rectal adenocarcinoma was the time between neoadjuvant therapy and surgery. This group of patients had less affected lymph nodes, less angiolymphatic and perineural involvement, a longer overall and disease-free survival, but no significant statistical difference was observed in local recurrence and distant metastasis. Although the complete pathologic remission was associated with better prognosis, this not implied in the cure of the disease for all patients.
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Vitor Augusto de
authors.initials: VA
authors.lastname: Andrade
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Claudio Saddy Rodrigues
authors.initials: CS
authors.lastname: Coy
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Raquel Franco
authors.initials: RF
authors.lastname: Leal
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: João José
authors.initials: JJ
authors.lastname: Fagundes
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Carlos Augusto Real
authors.initials: CA
authors.lastname: Martinez
authors.affiliation: Universidade Estadual de Campinas (UNICAMP), Campinas, SP, Brasil.
authors.forename: Maria de Lourdes Setsuko
authors.initials: Mde L
authors.lastname: Ayrizono
mesh_terms: D000230:Adenocarcinoma / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D060828:Induction Chemotherapy / Q000379:methods* / Q000401:mortality; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods* / Q000401:mortality; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000628:therapy*; D011379:Prognosis; D012004:Rectal Neoplasms / Q000556:secondary / Q000601:surgery / Q000628:therapy*; D012189:Retrospective Studies; D013997:Time Factors