05-05-2023 When to assign the T category as T0
Scenario number 1 No residual tumor at definitive surgery:
- Shave biopsy right arm: Malignant Melanoma, no ulceration, Breslow depth of invasion 0.55mm, pT1a
- Wide local excision-No residual tumor
Question: How will you assign the pT category?
- pT1a <8mm Without ulceration
- pT0 no evidence of primary tumor
Answer: pT1a
Rationale:
Refer to AJCC 8th Edition Chapter 1 General Staging Rules refer to page 11 for information on Timeframe/staging window for determining pathological stage and page 12 for instructions about Stage Classifications for Pathological Staging. Also refer to the specific chapter in the AJCC manual for the case you are abstracting. Pathological staging combines all the information from clinical staging and pathologic staging workup. Although the definitive surgery from the wide local excision showed no residual tumor, a pT0 would mean there was never any evidence of a primary tumor, but the patient definitely had evidence of tumor from the shave biopsy so a pT0 would not be applicable, be sure to use all the information available from both the clinical & pathologic timeframes.
Scenario number 2 No residual on resection after neoadjuvant therapy:
- Mammogram shows 3.1 cm RUOQ mass +invasive ductal carcinoma
- Patient undergoes neoadjuvant chemo/xrt
- Right Simple Mastectomy-shows no residual tumor
Question: How will you assign the ypT category?
- pT1a <8mm Without ulceration
- pT0 no evidence of primary tumor
Answer: pT0
Rationale:
Refer to AJCC 8th Edition Chapter 1 General Staging Rules refer to page 11 for information on Timeframe/staging window for determining post neoadjuvant therapy or posttherapy stage and page 13 for instructions about Stage Classifications for Posttherapy or post neoadjuvant therapy. Also refer to the specific chapter in the AJCC manual for the case you are abstracting. Posttherapy yp classification is used for staging after neoadjuvant therapy and planned neoadjvuant therapy surgery. For this breast case the ypT is determined by measuring the largest focus of residual invasive tumor. In this case, there was no residual tumor, assign ypT0.
Scenario number 3 Unknown Head and Neck Primary:
- Patient presents with metastatic cervical lymph nodes +squamous cell carcinoma, HPV+, EBV negative, after extensive clinical workup, felt to be a Head & Neck primary although a primary site was not found.
- Tumors identified by metastatic cervical lymph node(s) HPV+ EBV- should be abstracted as an oropharynx primary
Question: How will you assign the cT category?
- cT BLANK
- cTX
- cT0 No Primary identified
Answer: cT0
Rationale:
Refer to AJCC 8th Edition Chapter 1 General Staging Rules refer to page 11 for information on Timeframe/staging window for determining clinical stage, page 12 for instructions about Stage Classifications for clinical, and page 28 for instruction for cT0 and pT0. Also refer to the specific chapter in the AJCC manual for the case you are abstracting. If the clinical workup does not identify a primary tumor the T category will be assigned as a cT0.