Behind the Knife ABSITE 2026 - Oncology

Okay. Here we are again, behind the knife, ab site review. Today's high yield oncology. Okay. So, let's just get right into it. We're going to go through some immunotherapy agents and what we're going to do is I'm going to say the agents. And then I want you guys to tell me what the primary target and what the main uses of this immunotherapy agent is. Okay. Ready? I'm glad you have to say that. Yeah. Yeah. Okay. Kevin trans Tuzumab. HER2 NU. This is the Human Epidermal Growth Factor Receptor Tyrosine Kinase. And what's it used for? It's used in some breasts, esophageal, and gastric cancers. Okay, John Cetuximab. So that's your Endothelial Growth Factor Receptor, EGFR. It's used in colon and head and neck cancers. Okay, good. Kevin, back to you. And Matt, NU? Ooh, I know this one. CKIT. It's the Stem Cell Growth Factor Receptor used in GIST, and apparently also in leukemia. Okay, John, ipilimumab? Yeah, that's your anti CTLA 4. CTLA

4 promotes growth and function of T cells. It's used in melanoma. Okay, Kevin, nivalumab. I think this is what Jimmy Carter is on to fight his melanoma. It's an anti PD L1. It removes to checkpoint inhibition to allow T cells to target cancers. It's used in melanoma, lymphoma, colon, gastric, head and neck, liver cancers, and others. Okay John, back to you. Pembrolizumab. Yeah, Pembrolizumab. Pembrolizumab. Yeah, that's it. Yeah, it's an anti PD 1 receptor. It removes checkpoint inhibition to allow T cells to target cancers. It's used in melanoma, lung cancer, lymphoma, head and neck cancers, and many others. Okay. I'm glad we're finished with that. Okay. So let's move on to some common chemotherapeutic agents and their side effects. So an easy way to remember this is the chemotox man and just look to our, our outside companion to see that and memorize that image, but let's go through them briefly here. Okay. So, John,

we'll start with you. So. Cisplatin, carboplatin, what's the side effect? So usually, that's where you're going to have your ototoxicity and nephrotoxicity. Great. Kevin bleomycin? That's the pulmonary fibrosis. Okay. John doxorubicin? Yeah, well known for cardiotoxicity. Perfect. Kevin, cyclophosphamide? Hemorrhagic cystitis. John 5 FPU or 6 MP? Myelosuppression. Okay. Kevin, methotrexate? Myelosuppression. Yep. Myelosuppression as well. John, vincristine. That's where you get your peripheral neuropathy. Yep. Okay. So again we went through those, but look at that diagram and memorize that chemotoxin and it'll help you out a lot with those questions. Okay. So moving on, more high yield oncology. So let's look, let's talk about some of our hereditary cancer syndromes. So Kevin Lynch Syndrome, Hereditary Nonpolypopus Colon Cancer Syndrome what genes are involved? Yeah, so, most commonly it's MSH2, MLH1,

MSH6, PMS2. Okay. So these are your mispatch repair genes which result in carcinogenesis via an accelerated tumor progression. What are these patients, these Lynch syndrome patients what cancers are they at risk for? Yeah. I initially think of colon endometrium gastric but they're also small bowel pancreatic GU and ovarian. Okay, excellent. What are the screening recommendations Kevin for patients with the syndrome? Yes, you want to start your colonoscopies at the youngest age, at 20. You want to start your EGDs at 30 to 35. You need to do endometrial testing at 25 and the urinalysis starting at around 30 to 35. Okay, great. Golanosopy to 35, endometrial vacuum curatage starting at age 25 and urinalysis at 30 to 35. What is MIR TOR syndrome? So this is a form of Lynch syndrome that's characterized by sebaceous gland tumors and colon

and GU cancer tumors. Okay, excellent. Okay, John, now going to you for familial adenomatous polyposis polyposis rather. So this includes your Gardner syndrome. What genes are involved with this? That's your APC gene and the tumor suppressor gene, which regulates the intracytoplasmic pool of beta catedin. Okay, okay, and what are these again, FAP patients, what cancers are they at risk for? So, colorectal cancer is the most common. You have two types of FAP. Classic FAP, you have thousands of polyps by age 20 to 30. And then you have attenuated FAP, which is usually less than 100 polyps. Additionally, you can get gastric polyps, epidermoid cysts, desmoid tumors brain cancers, gallbladder, pancreas, bile duct, adrenal, thyroid, and liver tumors. Okay. And screening recommendations for FAP? So, upper endoscopy starting at age 20. Flex sig or colonoscopy starting at age 12. And a thyroid ultrasound

starting at age 20. So what about surgical prophylaxis for these FAP patients? Yeah, so colectomy and proctectomy are your surgical prophylaxis. This typically requires total proctocolectomy, but may consider rectal sparing approach with a total abdominal colectomy if limited disease in the rectum. However, this still would require surveillance of the rectal stump. Yeah, absolutely. You definitely need to surveil anything you leave behind. Okay, so, Kevin Turcotte syndrome, what is it? Yes, this is a variant of FAP or HNPCC with a brain tumor present. Okay, John, next one. Li Fraumeni syndrome. What gene is involved? So, that's your TP53 tumor suppressor gene. It results in a lack of tumor suppression and carcinogenesis. Okay, and what cancers are these patients at risk for? Lots. So, breast, gastric cancer, sarcomas, leukemia. Okay, and screening recommendations. So, annual whole body MRI, including a brain MRI, and upper and lower endoscopy starting at age

25. Okay. Okay, Kevin. Moving on. Pute's Jager syndrome. What gene is involved in Pute's Jager? That's the STK 11 gene. It's a tumor suppressor gene. Okay, and Fuchs, Jaegersen, Jerome patients are at risk for what kind of cancers? Yeah, I can see the picture in the textbook. It's the hamartomas, the mucotutaneous hyperpigmentation, gastric polyps, breast, ovarian, fallopian, cervical, thyroid, lung, pancreatic, and testicular cancer. Oh my goodness, that's a long list. Okay how about screen recommendations? So for this it's upper endoscopy, capsule endoscopy, and colonoscopy starting at the age of eight. Okay. Okay. So John, hereditary breast and ovarian cancer syndrome. What genes are involved with these? That's your BRCA1 and 2 genes, both tumor suppressor genes. Yeah. So those are the ones that we're a little bit more familiar with. What cancers are these patients at risk for? So breast, ovarian, pancreatic cancers, and melanoma. And screening recommendations for patients with the BRCA mutation? So we want to start breast

MRIs. At the age of 25 for men, you'll do annual breast examinations. And this is the type of disease that you need to have considered prophylactic bilateral mastectomies in high risk patients. Okay, great. Kevin, so hereditary diffuse gastric cancer. We talked about this a little bit in our stomach chapter, but what, what gene is involved with this? Yeah. So that's the CDH one gene. It's an E cadherin mutation resulting in the lack of tumor suppression and cell adhesion. Okay, and what it's a little bit obvious from the name, but what cancers are these patients at risk for? Gastric cancer with a greater than 80 percent lifetime risk. Okay, and how about your screening recommendations? So you want to start your upper endoscopy starting at the age of 20 and then consider a prophylactic total gastrectomy. Perfect. Okay. So those are hereditary cancer syndromes. You'll probably want to listen to that several times. Cause there's a lot of information and highly testable. So let's go into our quick hits then for our high yield oncology. So John, what is the extra colonic cancer that requires

surveillance after colectomy in patients with FAP? So this is duodenal carcinoma and you do upper endoscopy starting at age 20. Good, yeah, absolutely. Do not forget about that upper endoscopy after your colectomy for FAP. Kevin, what phase of cell division is the most vulnerable to radiation treatment? That's the M phase. M phase, yeah. Yep, that's a easy point to, to, to pick up on the upside. Okay John, Oncotype DX, what is the Oncotype DX gene assay? This is a 21 gene panel used as a prognostic tool to show the risk of developing breast cancer recurrence in ER positive tumors. Absolutely. This is a more recent thing that if you attend your institution's tumor boards, you probably hear all about it. So John, staying with you, how is this Oncotype DX recurrence score interpreted? So a score greater than or equal to 18 indicates a likely benefit from chemotherapy in addition to endocrine therapy for breast cancer. Okay. So let's just

go through some tumor markers. This is going to be real rapid fire. We're going to do what cancers are associated with these following tumor markers. So we're just going to go back and forth, Kevin and John. So I'll start with you, Kevin. CEA. Colon cancer. CA 19 9. Pancreatic cancer or hepatobiliary cancers. CA 125. Ovarian cancer. AFP. Hepatocellular carcinoma and testicular cancer, non seminoma. Okay. LDH. Melanoma. Intesticular cancers. PSA. Prostate cancer. Alk fos. Prostate cancer. HER2. That's breast, gastric, and esophageal cancers. Okay, last one. Chromogranin. Carcinoid tumor. Carcinoid tumor. Okay, excellent. So that is our high yield oncology abscite review. Thanks for listening.