Table 2 Survey questions with multiple case scenarios pertaining to neoadjuvantly treated rectal cancer
From: Challenges with colorectal cancer staging: results of an international study
Presented case scenarios/survey questions | Answer choices | Responses (percentage) |
|---|---|---|
1. A neoadjuvant-treated rectal cancer consists of large mucin pools that dissect into muscle wall. Viable tumor cells (floating in mucin pools, marked by arrow) are only found in the submucosa, but the same mucin pools extends into the muscularis propria where they contain no epithelium (Fig. 3a). Will you stage the tumor as: | a. ypT1 (tumor invades the submucosa) | 65% |
b. ypT2 (tumor invades the muscularis propria) | 35% | |
2. A neoadjuvant-treated rectal cancer consists of large mucin pools that dissect into mesorectum. Viable tumor cells (floating in mucin pools, marked by arrow) are only found up until the muscle wall, but the same mucin pools extend into the mesorectum where they contain no epithelium (Fig. 3b). Will you stage the tumor as: | a. ypT2 (tumor invades the muscularis propria) | 63% |
b. ypT3 (tumor invades through the muscularis propria into pericolorectal tissues) | 37% | |
3. A neoadjuvant-treated rectal cancer consists of large mucin pools that dissect into perirectal fat. Viable tumor cells (floating in mucin pools) are only found superficially in the submucosa, but the same mucin pools extends into the mesorectum where they contain no epithelium. Will you stage the tumor as: | a. ypT1 (tumor invades the submucosa) | 68% |
b. ypT3 (tumor invades through the muscularis propria into pericolorectal tissues) | 32% | |
4. A neoadjuvant-treated rectal cancer consists of large mucin pools that dissect into perirectal fat and extends up to the blue inked radial margin. The viable tumor cells in the mucin pools are identified in the mesorectal fat (>1 mm from the radial margin), but the same mucin pool dissects and extends up to the radial margin (Fig. 3c). Will you call the radial margin: | a. Positive | 33% |
b. Negative | 67% | |
5. A neoadjuvant-treated rectal cancer consists of large mucin pools that dissect into perirectal fat and extends up to the blue inked radial margin. The viable tumor cells in the same mucin pools are identified only up until the muscle wall. Will you call the radial margin: | a. Positive | 36% |
b. Negative | 65% | |
6. Lymph node dissection of a neoadjuvant-treated rectal cancer yields twenty-five lymph nodes. On H&E section, one of twenty-five lymph nodes show viable tumor within mucin pools. In this node, only few cells of viable tumor (measuring <0.2 mm, marked by arrow) is identified within the mucin pool, but the viable tumor together with the surrounding mucin pool measures 4 mm (Fig. 3d). How will you stage this: | a. ypN0 (with isolated tumor cells, defined as being <0.2 mm) | 24% |
b. ypN1 (regardless of the small size, in post neoadjuvant therapy) | 61% | |
c.ypN1 (one to three regional lymph nodes are positive (tumor in lymph nodes measuring ≥0.2 mm)) | 15% | |
7. Do you report tumor budding in neoadjuvant-treated rectal cancer patients? | a. Yes | 38% |
b. No | 62% | |
8. How will you stage residual tumor in a neoadjuvant-treated rectal cancer, when there is only residual intramucosal adenocarcinoma? | a. ypT0 | 26% |
b. ypTis | 74% | |
9. Do you diagnose mucinous carcinoma in a resection specimen of post neoadjuvant-treated rectal cancer? | a. Yes | 38% |
b. No | 62% |
