Radiation Oncology/Survival curve terminology


Definitions of terminology used in reporting cancer survival statistics. (NOTE: different authors may use varying definitions. Examples of trials using certain definitions are given for the purpose of comparison.)

Survival statisticsEdit

  • Overall survival (OS)
    • From date of diagnosis until death from any cause. [1]
  • Disease-free survival (DFS)
    • From date of diagnosis until date of first recurrence, locoregional or systemic. All other events were censored. [2]
    • Events are death or recurrence. [3] [4]
    • May also include second primary tumors (NSABP B-04).
    • Only includes pts who reached a CR at the end of treatment. [5]
  • Local-recurrence-free survival
  • Locoregional recurrence-free survival
    • 1) survival free of an isolated locoregional recurrence at a minimum of 6 months before a systemic event, or 2) survival free of locoregional recurrence occurring at any time before systemic recurrence. Other events were censored. [6]
  • Event-free survival
    • From date of diagnosis until 1) locoregional or systemic recurrence, 2) second malignancy, or 3) death from any cause [7]
    • 1) disease progression or relapse, institution of new unplanned anticancer treatment, or death from any cause [8]
  • Disease-specific survival
    • From diagnosis until death due to the cancer (with or without a prior known date of locoregional or systemic relapse). All other causes of death censored. [9]
  • Metastasis-free survival
  • Relapse-free survival (RFS)
    • Includes any recurrence. Does not include death (i.e., deaths are censored). May also include a contralateral breast cancer that is deemed a recurrence of the primary tumor (NSABP B-04).
  • Progression-free survival (PFS)
    • Same as EFS except late deaths not related to cancer or its treatment were excluded. 1) disease progression or relapse, institution of new unplanned anticancer treatment, or death related to disease [10]
  • Systemic disease-free survival
    • From date of diagnosis until date of first systemic recurrence, including: 1) systemic recurrence outside the locoregional area at any time before or after locoregional relapse, 2) systemic recurrence with or without locoregional relapse, or 3) death from cancer with no information on systemic recurrence. (All other causes of death were censored.) [11]
  • Freedom from progression (FFP)
    • Until first treatment failure. Includes failure to achieve CR (as opposed to RFS). Does not include deaths. [12] [13]

Tumor responseEdit

  • CR - complete response
    • CRu - complete response (undocumented)
  • PR - partial response
  • Stable disease
  • Progressive disease

ReferencesEdit

  • WHO definitions - PMID 7459811 — "Reporting results of cancer treatment" Miller AB et al. Cancer. 1981 Jan 1;47(1):207-14.
    • I believe this publication gives the definitions for partial response, complete response, etc.
  • RECIST criteria (2000) - Response Evaluation Criteria In Solid Tumors
  • RECIST 1.1 criteria (2009) - Response Evaluation Criteria In Solid Tumors Updated and Clarified
    • HIGHLIGHTS OF REVISED RECIST 1.1: Major changes include: Number of lesions required to be assess tumor burden for response determination has been reduced from a max of 10 to a max of 5 total. Assessment of pathological lymph nodes is now incorporated such that nodes with a short axis of 15 mm are considered measurable and assessable as target lesions. The short axis measurement should be included in the sum of lesions in calculation of tumour response. Nodes that shrink to <10mm short axis are considered normal. Confirmation of response is required for trials with response primary endpoint but is no longer required in randomised studies since the control arm serves as appropriate means of interpretation of data. Disease progression is clarified in several aspects: in addition to the previous definition of progression in target disease of 20% increase in sum, a 5mm absolute increase is now required as well to guard against over calling PD when the total sum is very small. Furthermore, there is guidance offered on what constitutes 'unequivocal progression' of non-measurable/non-target disease, a source of confusion in the original RECIST guideline. Finally, a section on detection of new lesions, including the interpretation of FDG-PET scan assessment is included. Imaging guidance: the revised RECIST includes a new imaging appendix with updated recommendations on the optimal anatomical assessment of lesions.
    • Full publication (PDF) PDF at CDC.gov (PMID 19097774)


  1. ^ - definition from British Columbia post-mastectomy RT trial
  2. ^ - GELA LNH 98-5, PMID 15867204
  3. ^ - Milan Hodgkin's disease trial - PMID 15199092
  4. ^ - European Group for Blood and Marrow Transplantation PDF
  5. ^ - PMID 16260700 "Disease free survival in colon cancer"
  6. ^ - EORTC H3 Hodgkin's trial - PMID 2578012

Standards for specific disease sites:

  1. ^ - Report of an international workshop to standardize response criteria for non-Hodgkin's lymphomas. NCI Sponsored International Working Group, PMID 10561185 (1999)