title: Long-term survival benefits of adjuvant chemotherapy by decreasing incidence of tumor recurrence without delaying relapse in stage III colorectal cancer.
abstract: OBJECTIVE
  To elucidate the survival benefits of adjuvant chemotherapy by decreasing incidence or by delaying time of tumor recurrence, we reported the long-term results of a nonrandomized prospective study comparing the adjuvant chemotherapy to no chemotherapy in stage III colorectal cancer.
  
  
  METHODS
  From 1991 to 1995, 463 patients with stage III colorectal cancer were divided to three groups which were no chemotherapy, weekly chemotherapy, and monthly chemotherapy (5-FU plus levamisole).
  
  
  RESULTS
  The recurrent incidence was significantly decreased in patients with chemotherapy (47.8% vs. 63.9% of no chemotherapy, P = 0.001), resulting into better survival. The 10-year cancer-specific and overall survival rates of patients with chemotherapy vs. no chemotherapy were 52.1% vs. 37.8% and 46.9% vs. 29.9%, respectively (P < 0.001). Weekly chemotherapy had better survival than monthly chemotherapy (P < 0.05). There was no significant difference in recurrent time or types between the patients with and without chemotherapy. The percentages of patients with recurrence happened within 3 years were 85.2% and 84.6% of those with and without chemotherapy, respectively. Patients with advanced stage of T4b invasion depth, N2, and central node invasion had no significant survival benefits by adjuvant chemotherapy.
  
  
  CONCLUSIONS
  Long-term survival benefits achieved by adjuvant chemotherapy is through decreasing recurrent incidence, not through postponing tumor recurrent time. That means adjuvant chemotherapy indeed cures some patients by eradicating occult tumor. In adjuvant setting, more powerful regimen for eradicating occult tumor is the keystone to improve long-term survival of stage III colorectal cancer.
authors.affiliation: Division of Colon and Rectal Surgery, Chang Gung Memorial Hospital, Linkou, Taiwan. wensy@adm.cgmh.org.tw
authors.forename: Wen-Sy
authors.initials: WS
authors.lastname: Tsai
authors.forename: Pao-Shiu
authors.initials: PS
authors.lastname: Hsieh
authors.forename: Chien-Yuh
authors.initials: CY
authors.lastname: Yeh
authors.forename: Jy-Ming
authors.initials: JM
authors.lastname: Chiang
authors.forename: Reiping
authors.initials: R
authors.lastname: Tang
authors.forename: Jinn-Shiun
authors.initials: JS
authors.lastname: Chen
authors.forename: Chung Rong
authors.initials: CR
authors.lastname: Changchien
authors.forename: Jeng Yi
authors.initials: JY
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000188:drug therapy* / Q000453:epidemiology / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000188:drug therapy / Q000453:epidemiology* / Q000473:pathology*; D009367:Neoplasm Staging; D011184:Postoperative Period; D016016:Proportional Hazards Models; D012004:Rectal Neoplasms / Q000401:mortality; D012008:Recurrence; D013624:Taiwan / Q000453:epidemiology; D013997:Time Factors; D055815:Young Adult