• Laterality
    Each lung is usually considered a separate primary; how often does true simultaneous bilateral lung cancer arise?
  • Contiguous/overlapping sites
    Lung tumors do not commonly spread directly from one lobe to a contiguous lobe; however direct extension into the hilum or mediastinum can be a problem in identifying the primary site, especially if there are separate lesions in the lung and hilum or mediastinum.
  • Multiple reports
    Multiple reports cause considerable confusion during the abstracting and tumor consolidation processes. Priorities are needed for determining whether one or multiple primaries and a single or complex histology are present.
  • NOS versus specific histology
    In particular, a sputum cytology may simply indicate non-small cell carcinoma, NOS. This information is often sufficient for the clinician to decide on a treatment pathway. A subsequent needle biopsy or tumor resection may yield a more specific diagnosis. In such cases, how important is it to code the initial diagnosis (non-small cell carcinoma) versus a more specific histology?
  • Time between diagnoses
    Given the generally poor prognosis of lung cancers and the sometimes extended pre-operative treatment period, should the two-month rule for defining a new primary be re-examined?
  • Multiple tumors
    There are a number of issues regarding multiple tumors in the lung:
    • Tumors with/without biopsy
      Can any assumptions be made about tumors that are not biopsied regarding whether they represent different primaries or different histologies?
    • Multiple tumors in same lung but only one biopsied
      Is it correct to assume that all tumors in the same lung are the same cell type? Existing rules default to abstracting case as a single primary with metastatic disease when only one tumor is biopsied.
    • Three or more tumors in one or both lungs are usually a single lung primary with metastatic disease
      Can this assumption be validated with current outcomes data?
  • Histology codes that are the same at the 3 digit level
    ICD-O-3 caused some changes to be needed in existing multiple primaries rules because of the placement of certain new malignant terms in three-digit rubrics with distinctly different malignant entities. For example:
    • Small cell (8041-8045) tumors / Non-small cell carcinoma, NOS (8046)
    • Bronchoalveolar (8250-8254) adenocarcinomas / Adenocarcinoma with mixed subtypes (8255)
  • Histology Group
    Lung cancer can be categorized into two broad groups of diseases, small cell/neuroendocrine and non-small cell carcinomas. The relationships between these two broad groups and the relationships of terms within each group should be arranged into some form of hierarchical order with definitions and priorities for coding.
  • Mixed histologies
    Pathologists have specific criteria for diagnosing certain lung malignancies that are not understood by most registrars. Clearer definitions and criteria for coding are needed for mixed and combination histologies.