Oncology1

Cancer's a pretty huge subject on the USMLE! I wish I had a mnemonic for all the different tumor suppressors, oncogenes, tumor markers, metastases, cancer associated syndromes, and what not, because they can be so hard to flat out memorize. However, I DO have a few tricks that I've found to be useful, that you may find useful, too.

Keep in mind this is not as high yield as most topics. I'd get a general feel, but to be honest, knowing what chromosome the tumor suppressor genes are on is very low yield. I'm not sure why I memorized it. But I did, so I thought I'd share how I did. If you're just starting on oncology, I'd actually look at oncology2 first. In fact, maybe don't even worry about oncology1. It's my OCD showing through.

Oncogenes


Okay, so you've probably memorized that erb-B2/HER2/Neu is related to breast and ovarian cancer. But did you know that the gene product is a tyrosine kinase? I've seen some questions that actually test on this fact. Now, it may not be worth your time, but if you're wanting to score extraordinarily high, it probably is. Anything extra thing you can know adds fuel to your arsenal against these step 1 questions. So without further adieu, here are some mnemonics and trends I've noticed for oncogenes.

"Able, Tyred (tired) Erb Retired." (I like to read it 'although still able, Erb retired because he was tired')

Tyrosine Kinases:
Abl - CML
Erb-B2 - breast, ovarian
Ret- MEN 2A, 2B

Myc:
all of these are transcription factors. Sorry, just a trend, no good mnemonic.
L-myc: Lungs
N-myc: Neuroblastoma
c-myc: Burkitt's (duh, you've got this one memorized by now. Don't forget t(8, 14)!)

Anti-Apoptosis
bcl-2: follicular lymphoma. Again, you've probably already memorized this, the two are like lamb and tuna fish (or maybe spaghetti and meatballs? Perhaps that's a better analogy?)

c-kit: cytokine receptor. Note also it's a tyrosine kinase receptor.

GTPase:
Ras: colon carcinoma. No good mnemonic for this. Sorry... but you should remember the the Ras is a GTPase involved in signal transduction from biochem. Or maybe it's just me that remembers that. Mmmm mmmmm biochem is AWEsome. Maybe you can think Ras --- GTPase? Now I'm stretching.

Tumor Suppressor Genes (TSG)


No great mnemonic for all of them, and for some reason I made a mnemonic relating to the chromosome that they're on. I had a qbank question that I think scarred (and scared) me into memorizing the chromosomes/tumor suppressor gene associations. This may not be worth your time.

p53: 17p. Note that the TSG's that begin with p will be on the p arm (short arm) of the chromosome. All the rest of the TSG's are on the q arm, except WT1 and VHL (ah, exceptions). Also note, 53 + 17 is a nice round number, 70. Works for me (sorry, some of my math tricks are lame. But when you have to flat out memorize numbers, I guess relating numbers to math is a way that helps).
-Another mnemonic for this to relate it to LI-Fraumeni: Take the LI and rotate it 180 degrees and you should have: 17.

RB: associated with bilateral retinoblastoma and osteosarcomas. On chromosome 13 (break down the initials RB, and highlight the left side of the R and the right side of the B. You get the number 13. Write RB on a piece of paper and you'll see what I mean).

VHL: VHL, 3 letters, 3rd chromosome. (and don't forget, on p arm!)

BRCA1, BRCA2: I just related these to the 2 main TSG's, p53 and Rb, which are 17 and 13. Alphabetically, p53 and Rb are in order, just like BRCA1 and BRCA2. So, BRCA1 is 17, and BRCA2 is 13. Another OCD mnemonic for you.

NF1: again, a lot of these important TSG's seem to be on chromosome 17, as is NF1. Maybe you can make the link that NF1 and BRCA1 are both on 17.
NF2: Take the 2, make 22. Chromosome 22.

p16: 9p. Again, it's on the p arm because it begins with p. And again, we want to add up to a nice number: 16 + 9 = 15. I don't know, multiples of 5 and 10 are just nicer, I guess. Somehow, remember this has to do with Melanoma.

DPC: Deleted in Pancreatic Cancer.
DCC: Deleted in Colon Cancer.
Both of these TSG's are on chromosome 18. Can't think of a good way to make this association.

APC: associated with FAP. Think polyp. 5 letters. Chromosome 5.

WT1: Just like we did for NF2, we take the 1, and make 11. Just write it twice. Also, it's easy to remember this is Wilm's Tumor, right? And RCC (that's also from the kidney, easy association). It's on the p arm!
-----

And that's it! Hope that benefits somebody.