Have you ever seen this as an early t1 representation and what would your approach be?

I am sorry to hear about your situation, especially at such a young age, but very glad you wrote to us to ask your question since I think your situation deserves special consideration (although we don't specifically address your specific situation in the webinar, there are many concepts there that apply to you and you will see below).

Indeed, rectal adenocarcinoma with micropapillary features is rare and usually aggressive (click here for a published statement about it).  That said, I am glad you have caught it early and have sought appropriate treatment.

I agree with the PET/CT (or PET/MRI) scan on the 4th.  If they have not done one yet, I would also ask for a CEA blood test (CEA is a tumor marker - you can hear about it in the video).

I think, given the micropapillary features and your young age, it is also important that your doctors send your tumor for comprehensive genetic analysis (next gen sequencing) including MSI testing.  Given your age, you should also have a test on normal cells (usually saliva or blood) looking for Lynch syndrome.  

I think it is also reasonable to begin treatment soon after, mostly to buy time for the genetic analysis to return and for further planning.  I recommend your doctors consider treatment similar to the following protocol (I recommend printing it out to show to them): https://www.clinicaltrials.gov/ct2/show/NCT04643366.  

I like starting with the chemotherapy alone (for 4 cycles) because it will enable you to get the results of genetic analysis prior to radiation or surgery. Given your young age, I would seek to minimize the impact of radiation that could cause issues later in life (ie. consider proton beam or focused intraoperative radiation) or if the genetic analysis comes back with MSI-high, then immunotherapy might cause the tumor to completely disappear (like in this recent NEJM article).  

The recommended treatment (as you can see from the referenced trial above) in the US is FOLFOX (a combination of several medicines), and it is usually tolerable with very low rates of hair loss (usually causes temporary nausea and vomiting).  However, the last of the medicines is oxaliplatin that can cause neuropathy (pins and needles feeling, numbness) over time.  I doubt permanent changes will happen during the first 4 cycles, but FOLFIRI (the European standard) or even 5-FU alone (infused or oral) could be alternatives to consider.  FOLFIRI would be a slight preference in my mind (it causes diarrhea as the main side effect), but I don't feel as strongly as I do about careful planning of the radiation, and think that all would be good to prevent spread while assessing further.

Finally, I strongly recommend getting a second opinion from an NCI accredited cancer center.   I have nothing against your current doctors - indeed, everything points to them recommending the US standard approach (including the watch and wait if the tumor completely disappears with chemoradiation therapy).  However, whenever a person so young is facing a serious situation, I would recommend a second opinion no matter what.   I see that UVA is 1.5 hours away.  A bit further (2.5 hours) is Johns Hopkins in Baltimore and I recommend seeing a surgeon like Dr. Efron, a medical oncologist like Dr. Leheru, and a radiation oncologist like Dr. Deville (you can call the main number and request them).  I think their program would be comprehensive, including fertility preservation, etc. as exemplified by this video about colon and rectal cancer in young people.  UPMC Hillman in Pittsburgh is also 2.5 hours away and would be a good choice too - if you are interested, I am happy to recommend people there too (and you'd want to check to make sure your insurance would cover out of state).  In the end, they may recommend therapy that can still be given at UVA, but I would ask for their evaluation (including on the diagnosis to confirm the rare subtype).  With the chemo on board, you should have time to explore and execute a well-informed plan.

Despite the shock of such a diagnosis, I think you are doing a great job in getting the best care and attention.  A few more well directed efforts is likely to optimize your outcome, hopefully avoiding surgery completely or if needed no colostomy.  We are here to help guide you further if you are interested in having us quarterback these efforts, including contacting other doctors on your behalf.  I hope you find this information helpful, and we would love to hear how you do.