AOCNP Study Guide 2026

Tobacco is carcinogenic across multiple organ systems — smoking causes 30% of all cancer deaths and cessation reduces risk for at least 12 different cancer types.

ASCO/NCCN guidelines for colorectal cancer surveillance recommend colonoscopy at 1 year after surgery (or within 3–6 months if preoperative colonoscopy was incomplete). If normal, repeat at 3 years, then every 5 years, along with CEA monitoring every 3–6 months for 5 years and CT chest/abdomen/pelvis annually for 3–5 years.

Anti-EGFR monoclonal antibodies (cetuximab, panitumumab) are only effective in metastatic colorectal cancer patients with RAS/RAF wild-type tumors. KRAS mutations cause downstream EGFR-independent activation, rendering anti-EGFR therapy ineffective in mutant patients.

Chemotherapy and radiation therapy are more effective against cells that are growing more quickly.

When the GI tract is functional, enteral nutrition (via NG tube or prophylactic PEG/RIG) is the preferred route and is supported by ASPEN, ESPEN, and ASCO guidelines for patients who cannot maintain adequate oral intake. Enteral feeding maintains gut integrity, reduces infection risk, and is more physiologic than parenteral nutrition. TPN is reserved for patients with a non-functional GI tract. Oral supplements alone are insufficient if mucositis prevents adequate intake. IV dextrose provides calories but no protein or micronutrients.

Dumping syndrome results from rapid gastric emptying of hyperosmolar contents into the small bowel. Early dumping (within 30 min) causes GI symptoms (nausea, cramping, diarrhea) and vasomotor symptoms (flushing, diaphoresis, tachycardia). Late dumping (1–3 h) causes reactive hypoglycemia. Management includes dietary modifications and small frequent meals.