INTRODUCTION TO CANCER STAGING

Transcription

1 INTRODUCTION TO CANCER STAGING Patravoot Vatanasapt, MD Dept. Otorhinolaryngology Khon Kaen Cancer Registry Faculty of Medicine Khon Kaen University THAILAND

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3 Staging is the attempt to assess the size of a tumor and its extent of involvement throughout the body. It is a simple, clear way of assigning patients to group which differ in the extent of their disease.

4 Survivals of oral cancer in Khon Kaen, Thailand ( ) Survival Stage 1 Median survival time = years Stage 2 Median survival time = 4.71 years Stage3 Median survival time =1.35 years Stage4 Median Survival time =0.72 years Years Unknown stage

5 Rationales for cancer staging It s necessary to evaluate results of cancer treatment and clinical trials, as staging confounds the treatment outcomes. Facilitates exchange and comparison of information among treatment centers, cancer registries, or populations. It serve as basis for clinical and translational cancer research Cancer staging defines prognosis of the patients It determines appropriate treatment It is an indicator for effects of cancer screening Bases on experience and outcomes of prior patients

6 Staging systems TNM staging system (UICC and AJCC) SEER summary Staging (NCI of USA) FIGO staging (cervical and ovarian cancer) Dukes Staging System (CA Colon and rectum) - obsolete Clark s level (Melanoma and skin - depth & layers) Breslow s classification (Melanoma and skin - thickness) Murphy (lymphoma)

7 TNM staging system UICC (International Union Against Cancer)1954 AJCC (American Joint Committee on Cancer) 1959 Uniform classification after AJCC, 1988 Anatomical extent of the tumor Histological grading (soft tissue sarcoma) Age (thyroid cancer)

8 T umor Direct invasion Nodal spreading in the region Lymphatic spreading M etastasis Hematologic / Lymphatic spreading Grouping cases with similar prognosis

9 Stage classification Clinical (ctnm) Pathologic (ptnm) Postneoadjuvant therapy (yctnm / yptnm) Retreatment (rtnm) Autopsy (atnm)

10 Introduction to T T category Defined by size, and/or Contiguous extension of primary tumor T specifically designed for each primary site Roles of size and contiguous spread depend on site characteristics Primary Tumor (T) valid values T0 No evidence of primary tumor Tis Carcinoma in situ T1,T2,T3,T4 Increasing size and/or local extension of primary tumor TX Primary tumor cannot be assessed (minimize use of TX)

11 Introduction to N N category Defined by absence or presence of cancer in regional draining lymph nodes N involvement categorized specifically for each site by Number of positive nodes and/or Involvement of specific regional nodal groups Regional Lymph nodes (N) valid values N0 N1,N2,N3 NX No regional lymph node metastasis Increasing number or extent of regional lymph node involvement Regional lymph node cannot be assessed (minimize use of NX)

12 Introduction to M M category Defined by absence or presence of distant spread or metastases Generally in locations to which cancer is spread by Vascular channels or Lymphatics beyond nodes defined as regional M specifically designed for some sites Subcategories for detailed areas of involvement Distant Metastasis (M) valid values M0 M1 No distant metastases Distant metastases present MX designation has been eliminated from AJCC TNM system

13 General rules 1. All cases should have microscopic confirmation Case without confirmation Only rarely should cases not have biopsy or cytology Can be staged using presumed histology Survival must be analyzed separately for these cases * Confounder, misclassification

14 General rules 2. Eligible time period for clinical staging Information before start of definitive treatment, or Within 4 months after date of diagnosis Use which of above is shorter time As long as no progression Definitive treatment includes Surgical resection, Systemic therapy, Radiation therapy, Active surveillance, and Palliative care

15 General rules 3. Progression of disease Evidence of disease progression If before start of any treatment Do not use this information for assigning stage Evidence of disease progression before treatment Use only information before progression to assign stage

16 General rules 4. Uncertain information Assign the lower (lesser) category or stage group If uncertain or unclear information Not enough information to definitely choose Commonly called downstaging Does NOT apply to unknown information

17 General rules 4. Uncertain information Example - Imaging unclear if one node (n1) or two node (N2) are involved - Use N1 - Colonoscopy does not provide information on T category of colon - Use TX (unknown) Physician may make clinical judgments for patient care

18 General rules 4. Uncertain information Example - Imaging unclear if one node (n1) or two node (N2) are involved - Use N1 - Colonoscopy does not provide information on T category of colon - Use TX (unknown) Physician may make clinical judgments for patient care

19 General rules 5. Nonanatomic factors not available Factors - Thyroid cancer: age / histology - Soft tissue sarcoma : grading Gastrointestinal stream tumor - mitotic rate - Use non anatomic factor as X in stage table. If it is not available, use the lowest level or least advanced category. - Case assigned based on lowest or least advanced factor

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21 Extents classification Extent of spread of a particular cancer In-situ Localized Regional Distant Unknown

22 In situ stage

23 Localized stage

24 Regional stage

25 Distant stage

26 SEER summary staging Code Definition 0 In situ 1 Localized only 2 Regional by direct extension only 3 Regional lymph nodes involved only 4 Regional by BOTH direct extension AND lymph node involvement 5 Regional, NOS (Not Otherwise Specified) 7 Distant site(s)/node(s) involved 9 Unknown if extension or metastasis (unstaged, unknown, or unspecified) Death certificate only case

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29 Staging Stage of cancer is assigned after the extent of the tumor in the body has been determined Determination of the site of origin (primary) Review of History / Physical examination Imaging / scans / endoscopy reports Operative reports Pathology reports (includes cytology, hematology, stops) Progress note Discharge summary

30 Determination the primary site!!

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32 Conclusion Cancer staging is necessary in clinical care, research, and registration TNM classification and Extent classification are most commonly used in cancer registry Consistent rules and practice is crucial in maintaining a valid information