For efficient assignment of the summary stage code, here are some additional guidelines. Three of the summary staging categories can be ruled out quickly: in situ, distant and localized.
- Rule out in situ stage disease. Carcinomas and melanomas are the only types of cancer that can be classified as in situ. Only carcinomas have a basement membrane. Sarcomas are never described as in situ. A pathologist must examine the primary organ and state that the tumor is in situ. If the cancer is anything except a carcinoma or melanoma, it cannot be in situ.
- If there is any evidence of invasion (or extension to), nodal involvement, or metastatic spread, the case is not in situ even if the pathology report so states. This is a common error in staging cervical cancer where the pathology report states that the cancer is "in situ with microinvasion" -- such a case would be staged as localized because the microinvasion is evidence that the tumor has broken through the basement membrane and is therefore no longer "in place" (which is the literal translation of the Latin term in situ).
- Rule out distant disease. If metastases can be documented, there is no need to spend a great deal of time identifying local or regional spread. If distant metastases are recorded on x-ray or needle biopsy, for example, the stage is already determined as distant and the patient does not need to undergo a lot of other tests.
- Hematopoietic diseases, such as leukemia and multiple myeloma, are considered disseminated or distant at the time of diagnosis.
- Rule out distant spread by reading the operative report for comments about "seeding," "implants," "liver nodules," or other indications of metastases. Read all of the available diagnostic reports for references to distant disease.
- If nodes, organs, or adjacent tissues are not specifically mentioned in the description of the various categories, attempt to cross-reference the term you have with those outlined. If there is no match, assume the site in question represents distant disease.
- Rule out that the cancer is "confined to the organ of origin." In order for a lesion to be classified as localized, it must not extend beyond the outer limits of the organ and there must be no evidence of metastases anywhere else.
- Terms such as "blood vessel invasion" or "perineural lymphatic invasion" do not necessarily indicate that the cancer has spread beyond the primary organ. If tumor at the primary site has invaded lymph or blood vessels, there is the potential for malignant cells to be transported throughout the body (link to step 1,2,3 images). Step 1 (invasion) has occurred, but not necessarily steps 2 (transport of cancer cells) and 3 (growth at the secondary site). The case may still be localized.
- Vascular invasion within the primary is not a determining factor in changing the stage unless there is definite evidence of tumor at distant sites.
- If in situ, localized and distant categories have been ruled out, the stage is regional (one of the four regionals available).
- For carcinomas, if there are lymph nodes involved with the tumor, the stage is at least regional lymph nodes.
- For tissues, structures, and lymph nodes, assume ipsilateral unless stated to be contralateral or bilateral.