title: Impact of Dose Reductions, Delays Between Chemotherapy Cycles, and/or Shorter Courses of Adjuvant Chemotherapy in Stage II and III Colorectal Cancer Patients: a Single-Center Retrospective Study.
abstract: OBJECTIVE
  Most stage II or III colorectal cancer patients are receiving nowadays a 4 to 6-month course of adjuvant chemotherapy. However, delays between cycles, reductions in the doses of chemotherapy drugs, or even permanent omissions of chemotherapy cycles might take place due to side effects or patient's preference. We examined the impact of these treatment modifications on recurrence-free survival (RFS) and overall survival (OS).
  
  
  METHODS
  We retrospectively collected data from colorectal cancer patients who had received adjuvant chemotherapy in our Department. Patients were categorized in five groups based on whether they had or not delays between chemotherapy cycles, dose reductions, and permanent omissions of chemotherapy cycles. Three-year RFS and OS of the five different groups were compared using the log-rank test and the Sidak approach.
  
  
  RESULTS
  Five hundred and eight patients received treatment. Twenty seven percent of the patients had the full course of chemotherapy; the others had delays, dose reductions, or early termination of the treatment. No statistically significant differences were observed in 3-year RFS and OS between the five groups. A trend for worse RFS was noticed with early termination of treatment. A similar trend was also noticed for OS but only for stage II patients.
  
  
  CONCLUSIONS
  In colorectal cancer patients, receiving adjuvant chemotherapy, delays between chemotherapy cycles, dose reductions of chemotherapy drugs, or even early termination of the treatment course do not seem to have a negative impact in 3-year RFS and OS; however, due to the trend of worse RFS in patients receiving shorter courses of chemotherapy, further studies are needed.
authors.affiliation: 3rd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece. josephsgouros@yahoo.co.uk.
authors.forename: Joseph
authors.initials: J
authors.lastname: Sgouros
authors.affiliation: 2nd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece.
authors.forename: Gerasimos
authors.initials: G
authors.lastname: Aravantinos
authors.affiliation: Health Data Specialists, Ltd, 22 Katehaki Str, Athens, 11525, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Kouvatseas
authors.affiliation: 3rd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece.
authors.forename: Anna
authors.initials: A
authors.lastname: Rapti
authors.affiliation: 3rd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece.
authors.forename: George
authors.initials: G
authors.lastname: Stamoulis
authors.affiliation: 3rd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Bisvikis
authors.affiliation: 3rd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece.
authors.forename: Helen
authors.initials: H
authors.lastname: Res
authors.affiliation: 3rd Medical Oncology Department, "Agii Anargiri" General Cancer Hospital, Kaliftaki, N. Kifissia, 14564, Greece.
authors.forename: Epameinondas
authors.initials: E
authors.lastname: Samantas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D017024:Chemotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000145:classification / Q000188:drug therapy* / Q000473:pathology; D004305:Dose-Response Relationship, Drug; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000145:classification / Q000188:drug therapy* / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate; D013997:Time Factors; D061665:Time-to-Treatment
keywords: Adjuvant chemotherapy; Colorectal cancer; Delays between chemotherapy cycles; Dose reductions; Omission of chemotherapy cycles