Tumors PDF

Classification based on differentiation, growth, and spreading Grading of tumors based on differentiation of the cells  Grade 1 through Grade 4  Grade 1 is well differentiated  Grade 2 & 3 progressively poorly differentiated  Grade 4 is anaplastic  Tumor cells are a set o...

Classification based on differentiation, growth, and spreading Grading of tumors based on differentiation of the cells  Grade 1 through Grade 4  Grade 1 is well differentiated  Grade 2 & 3 progressively poorly differentiated  Grade 4 is anaplastic  Tumor cells are a set of identical cells descended from a single ancestor cell = tumor is monoclonal  Multiple cofactors in addition to “initial” transformation of the normal cell line into a malignant cell  Clonal expansion- Uncontrolled proliferation of its descendants  Each line will compete for resources and aquire new characteristics: tumor cell variation TNM Classification: Tumor Growth (T)  Usual life span of a tumor  Tumor Growth Factors: fast & slow growth  The Nourishment of Tumors  Tumors produce angiogenesis factors that cause the production of new blood vessels  Benign tumors grow slowly so that they do not usually rapidly out grow their blood supply, but the cells in the center of the tumor may show some degeneration  Malignant tumors grow so rapidly that they do outgrow their blood supply, so the center of the tumor shows necrosis. The vessels that they produce are often abnormal and so they are prone to rupture and hemorrhage o T is local tumor size – o Tx: tumor cannot be assessed o Tis: carcinoma in situ o T0: no evidence of tumor (observable >1-2 mm) o T1, T2, T3, T4: size and/or extension of the primary tumor Tumor spread o Local invasion- direct spread  Malignant neoplasms are characterized by progressive infiltration, invasion, destruction and penetration of the surrounding tissues.  Carcinoma spread initially / mostly lymphatic  Hematogenous spread- typical of sarcomas  End in lymph nodes and in organs lungs, liver, bones, brain, peritoneum, adrenals (Ki, Lu) developing new tumors = metastasis  Transcoelomic spread – through cavities, mostly peritoneal or pleural Dr M Hossu Notes 150  Lymphatic nodes(N) o Nx: lymph nodes cannot be assessed o N0: no regional lymph nodes metastasis o N1: regional lymph node metastasis present; at some sites, tumor spread to closest or small number of regional lymph nodes  Sentinel node o N2: tumor spread to an extent between N1 and N3 (N2 is not used at all sites) o N3: tumor spread to more distant or numerous regional lymph nodes M stands for metastases- o M0 means no metastases, o M1 means metastases are present Staging of tumors  Stage 0: carcinoma in situ, abnormal cells growing in their normal place o "in situ" from Latin for "in its place"  Stage I: cancers are localized to one part of the body. o Attempt for surgical removal (if small enough and N0 or excisable N1).  Stage II: cancers are locally advanced. o chemotherapy, radiation, or surgery.  Stage III: cancers are also locally advanced with extended N. o The specific criteria for Stages II and III therefore differ according to type 7 place o chemotherapy, radiation, surgery combo.  Stage IV: cancers have metastasized, Dr M Hossu Notes 151  Example: Breast Cancer Tumor size (T)  T0 (T zero): There is no evidence of cancer in the breast.  Tis: carcinoma in situ. The cancer is confined within the ducts of the breast tissue and has not spread into the surrounding tissue. DCIS and Paget's disease of the nipple  T1: < 20 millimeters (mm) in size at its widest area. This is a little less than an inch. o T1mi is a tumor that is 1 mm or smaller. o T1a is a tumor that is larger than 1 mm but 5 mm or smaller. o T1b is a tumor that is larger than 5 mm but 10 mm or smaller. o T1c is a tumor that is larger than 10 mm but 20 mm or smaller.  T2: larger than 20 mm but not larger than 50 mm.  T3: The tumor is larger than 50 mm.  T4: The tumor falls into 1 of the following groups: o T4a means the tumor has grown into the chest wall. o T4b is when the tumor has grown into the skin. o T4c is cancer that has grown into the chest wall and the skin. o T4d is inflammatory breast cancer. Node (N)  NX: The lymph nodes were not evaluated.  N0: No cancer or smaller than 0.2 mm in the lymph nodes.  N1: The cancer has spread to 1 to 3 axillary lymph nodes and/or the internal mammary lymph nodes  N2: The cancer has spread to 4 to 9 axillary lymph nodes. Or, it has spread to the internal mammary lymph nodes, but not the axillary lymph nodes.  N3: The cancer has spread to 10 or more axillary lymph nodes, or it has spread to the infra- or supra-clavicular lymph nodes Dr M Hossu Notes 152