title: A single-institution experience of salvage therapy for patients with early and locally advanced breast cancer who progress during neoadjuvant chemotherapy.
abstract: OBJECTIVE
  Progression during neoadjuvant chemotherapy (NAT) for early and locally advanced breast cancer is generally uncommon. However, these patients tend to do poorly, and salvage therapy (ST) use is variable and often not well defined. We aimed to establish the characteristics and outcomes of breast cancer (BC) patients progressing on NAT, report the patterns of institutional ST usage, and identify predictors of ST failure.
  
  
  METHODS
  A retrospective review was conducted using the "Biomatrix" institutional database. Fisher's exact test was used to study the association between baseline characteristics and progression after ST. Survival outcomes were estimated using Kaplan-Meier. Disease-Free Survival 1 (DFS1) and DFS2 represent the time between diagnosis and first progression, and the first and second progression, respectively. The log-rank test was used to compare survival outcomes between different ST types.
  
  
  RESULTS
  Thirty patients out of 413 (7.2%) progressed on primary NAT, with a median follow-up of 28.52 months (13.77-46.97) and a mean age of 57 years (standard deviation: 12). The two most frequently used ST modalities were surgery (43%) and radiation with concurrent cisplatin chemotherapy (CT/RT) (40%). Eighty percent of the patients made it to subsequent surgery and among those, 11 (69%) were initially not operable and their tumors were rendered surgically removable after ST. The initial tumor stage and grade, and the presence of lymphovascular invasion predicted progression after ST (p = 0.02, p = 0.03 and p = 0.01, respectively). Median DFS1, DFS2, and overall survival were 4.4 months (95% CI 3.6-5.7), 14.8 months (95% CI 2.37-NR), and 39.5 months (95% CI 22.73-NR), respectively. No difference in survival outcomes based on ST type was seen.
  
  
  CONCLUSIONS
  In this evaluated cohort and despite potential poorer outcomes, patients progressing on NAT responded well to ST, became operable, and had promising survival outcomes. Appropriate selection of ST is crucial, and can help improve outcomes in such patients.
authors.affiliation: Medical Oncology Division, Department of Medicine, Sunnybrook Odette Cancer Centre, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada. raphaeljack13@hotmail.com.
authors.forename: Jacques
authors.initials: J
authors.lastname: Raphael
authors.affiliation: Medical Oncology Division, Department of Medicine, Sunnybrook Odette Cancer Centre, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada.
authors.forename: Thivaher
authors.initials: T
authors.lastname: Paramsothy
authors.affiliation: Sunnybrook Research Institute, 2075 Bayview avenue, Toronto, ON, M4N 3M5, Canada.
authors.forename: Nim
authors.initials: N
authors.lastname: Li
authors.affiliation: Radiation Oncology Department, Sunnybrook Odette Cancer Centre, 2075 Bayview Avenue, Toronto, ON, M4N 3M5, Canada.
authors.forename: Justin
authors.initials: J
authors.lastname: Lee
authors.affiliation: Medical Oncology Division, Department of Medicine, Sunnybrook Odette Cancer Centre, 2075 Bayview Avenue, Toronto, ON, M4N3M5, Canada.
authors.forename: Sonal
authors.initials: S
authors.lastname: Gandhi
mesh_terms: D000368:Aged; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D001943:Breast Neoplasms / Q000628:therapy*; D002945:Cisplatin / Q000008:administration & dosage* / Q000627:therapeutic use; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011878:Radiotherapy; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000379:methods*; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D000970:Antineoplastic Agents; D002945:Cisplatin
keywords: Breast cancer; Neoadjuvant chemotherapy; Progression; Salvage therapy