Which factor is excluded when counting CS data items?

• A. Site-specific factors
• B. Tumor size
• C. Depth of invasion
• D. Distant lymph nodes

Answer: (A)

When you count Collaborative Stage (CS) data items, you’re looking at the standard elements that apply across most cancer sites to describe the tumor, nodal involvement, and metastasis. Items like tumor size and depth of invasion are part of that general CS data item set and are included in the count because they consistently contribute to staging across many cancers. Site-specific factors, however, are collected only for certain tumor sites and are not part of the universal CS item tally. They’re tracked separately as site-specific factors because their applicability varies by site, so they’re excluded from the core CS data item count. This distinction keeps the CS data consistent and comparable across different cancers, while still recording additional, site-dependent details when relevant.