Behind the Knife ABSITE 2026: High-Yield Oncology Review

Immunotherapy Agents and Targets

• 🎯 Trastuzumab targets HER2 and is used in breast, esophageal, and gastric cancers.
• 🎯 Cetuximab targets EGFR and is used in colon and head and neck cancers.
• 🎯 Imatinib targets CKIT (stem cell growth factor receptor) and is used in GIST and leukemia.
• 🎯 Ipilimumab is an anti-CTLA4 agent that promotes T-cell growth and function, used in melanoma.
• 🎯 Nivolumab is an anti-PDL1 agent that removes checkpoint inhibition, used in melanoma, lymphoma, colon, gastric, and head and neck cancers.
• 🎯 Pembrolizumab is an anti-PD1 receptor agent that removes checkpoint inhibition, used in melanoma, lung cancer, lymphoma, and head and neck cancers.

Chemotherapeutic Agents and Side Effects

• ⚠️ Cisplatin/Carboplatin are associated with ototoxicity and nephrotoxicity.
• ⚠️ Bleomycin can cause pulmonary fibrosis.
• ⚠️ Doxorubicin is well-known for cardiotoxicity.
• ⚠️ Cyclophosphamide can lead to hemorrhagic cystitis.
• ⚠️ 5-FU/6-MP and Methotrexate are associated with myelosuppression.
• ⚠️ Vincristine causes peripheral neuropathy.

Hereditary Cancer Syndromes

• 🧬 Lynch Syndrome (HNPCC) involves mismatch repair genes (MSH2, MLH1, MSH6, PMS2) and increases risk for colon, endometrium, gastric, small bowel, pancreatic, GU, and ovarian cancers. Screening includes colonoscopies starting at age 20 and EGDs at 30-35.
• 🧬 Muir-Torre Syndrome is a variant of Lynch syndrome with sebaceous gland tumors and colon/GU cancers.
• 🧬 Familial Adenomatous Polyposis (FAP) involves the APC gene and increases risk for colorectal cancer, gastric polyps, desmoid tumors, and brain, gallbladder, pancreas, thyroid, and liver tumors. Screening includes upper endoscopy starting at age 20 and colonoscopy at age 12.
• 🧬 Turcot Syndrome is a variant of FAP or HNPCC with a brain tumor.
• 🧬 Li-Fraumeni Syndrome involves the TP53 tumor suppressor gene, increasing risk for breast, gastric cancers, sarcomas, and leukemia. Screening includes annual whole-body MRIs and colonoscopies at age 25.
• 🧬 Peutz-Jeghers Syndrome involves the STK11 gene and is associated with mucocutaneous hyperpigmentation, gastric polyps, and increased risk for breast, ovarian, cervical, lung, pancreatic, and testicular cancers. Screening includes upper endoscopy and colonoscopy starting at age 8.
• 🧬 Hereditary Breast and Ovarian Cancer Syndrome (HBOC) involves BRCA1 and BRCA2 genes, increasing risk for breast, ovarian, pancreatic cancers, and melanoma. Screening includes breast MRIs at age 25 and consideration for prophylactic mastectomy.
• 🧬 Hereditary Diffuse Gastric Cancer involves the CDH1 gene, with a high lifetime risk of gastric cancer. Screening includes upper endoscopy starting at age 20, with consideration for prophylactic gastrectomy.

Quick Hits in Oncology

• 💡 Duodenal carcinoma requires surveillance after colectomy in FAP patients, with upper endoscopy starting at age 20.
• 💡 The M-phase of cell division is most vulnerable to radiation treatment.
• 💡 Oncotype DX is a 21-gene assay used as a prognostic tool for breast cancer recurrence risk in ER-positive tumors; a score >= 18 suggests benefit from chemotherapy.

Tumor Markers and Associated Cancers

• 📊 CA19-9 is associated with pancreatic and bile duct cancers.
• 📊 CA-125 is associated with ovarian cancer.
• 📊 AFP is associated with hepatocellular carcinoma and non-seminoma testicular cancer.
• 📊 LDH is associated with melanoma and testicular cancers.
• 📊 PSA and Alpha-fetoprotein are associated with prostate cancer.
• 📊 HER2 is associated with breast, gastric, and esophageal cancers.
• 📊 Chromogranin is associated with carcinoid tumors.