I think I can answer some of your questions, although I actually had Hodgkin's Lymphoma, not breast cancer.  The effects of chemo can be slightly different depending on the type of chemo (type of poison used, b/c that's exactly what it is) and it can also be different for the same type of chemo, but each person can have a slightly different response.  What I can give you are guidelines & it's likely to be true for you - just not 100% exactly the same b/c it can be different by type & by individual response.

After I would have a chemo treatment, starting a few hours afterwards, I would have increased nausea.  The nausea would pretty much completely go away by the 5th day after treatment.  I had chemo once every two weeks for 6 months.  The nausea medications were very helpful, but I always thought that I had more nausea than most people.  But, even still, it really wasn't that bad.  I only threw up twice during the entire 6 months.  Much more common was getting nauseous suddenly & dry heaving until the medication could take effect.  This typically happened b/c I waited a little too long before taking the medication again.

As for absorption of the nausea medication - one of the pills was absorbed through the mucous membranes of my mouth, called odansetron.  You place it against the inside of your cheek & it dissolves.  Takes about a minute.  Doesn't taste bad (not like candy, either), just not that bad.  That medication, the odansetron, worked awesome.  For me, I think it worked better than the other medication, prochlorazine, b/c that one was a swallowed pill.  Remember, I did not have a gastric bypass, I had the duodenal switch & they really are very different in terms of medication.  I have a fully functioning regular stomach that is just smaller in volume, but I still digest inside the stomach like normal.  I absorb far less in the small intestine than bypassers, though.  That's why I don't think the swallowed pill, prochlorazine, was as helpful to me as the odansetron.  For you, you will absorb more of it than I did so long as it doesn't upset your stomach so that you throw it up.  Will that happen?  I don't think so, though can't be sure.  I remember a couple of the oncologist doctors talking to me about it right before I started treatment & they were only familiar with banders or bypassers & they said that, in their experience & opinion, I wouldn't have any more trouble keeping it down than I would my regular vitamins.  

My advice would be to definitely ask for odansetron, even if you're not prescribed it & cite your WLS as why you need it.  It's much more expensive than prochlorazine.  The best thing to do is to take both & then you can "flip flop" them.  Each of them can only be taken every 6 - 8 hrs so if you monitor taking them on time well, you should be fine with eating something before taking your prochlorazine - or whatever oral pill to swallow they give you.  I would definitely get the odansetron, though!

As for WL - it will likely continue so long as you're still in your WL window UNLESS you're also taking heavy amounts of steoroids.  I was given a steoroid with each chemo dose, but only in the IV with the actual chemo, otherwise I didn't have to take it.  I know other people (who didn't have WLS), but are cancer survivors who have complained about gained 10 - 30 pounds from a combination of steoroids & decreased physical activity b/c of the effects of treatment.  Fatigue is a very, very real thing & affects upwards of 90% of people.  Your body will be undergoing a lot of stress in the next few months & NEEDS adequate nutrition.  Please, do not try to overly limit what you eat - just eat healthy & let your body get the nutrition it needs to (literally) survive & be healthy.  If you're still in your WL window, you will likely continue to lose weight, but honestly, that shouldn't be your main priority right now.  Surviving is.

As for exercise, I would strongly suggest to continue exercising, but you will likely find that you can't do as much - that's completely normal.  There's a lot of research that suggests exercising during cancer treatment helps to control fatigue & also helps your mood.

I would also strongly suggest that you join a cancer treatment group.  There are things you can discuss with them that you will find helpful b/c you don't have to worry about your family's feelings &/or the fact that others who love & support you ultimately can't exactly relate to what you're going through.  I believe Gilda's Club is also in Canada.  You can also try googling it with your city name or ask the cancer center social worker for support resources.

Hope this helps :)  Good luck with everything & write if you need/ want, I'm always willing to help!

Lisa

Question-did you have gastric surgery  after you had your cancer treatment. I am trying to find out how chemo works when you have had gastric surgery already.
Hoping if I ask all of you on this sight someone will be able to give me info. Really hard to find it out.
Thanks

I am out 5 months from having gastrobipass surgery and have done well 81 lbs. feeling good can eat almost everything in small amounts, and now just found out breast cancer, early stage however as its atypical will need chemo and radiation therapy after surgery. I am in Ontario and we do not have alot of examples of this, even at Princess Margret which is our big cancer hospital in Toronto. I am hoping since U.S. has so many more people that there are some of you out there, sadly like me who have had to go through chemo. I am worried about having cancer but also worried about how gastric bi pass impacts on the chemo drugs doing what they should and also how our new stomach's handle the chemo which is hard on regular stomach's.
Help.
If you know anyone would you please ask them to respond
Thanks so much

Hi David,    I was diagnosed October of 2010 with Lymphoma, received chemo without any ill effects different from any other cancer patient.   With the Roux n Y surgery you always have the
vitamin deficiencies and they have to be watched closer during your chemo.  Your WBC/ immune system is very stressed, iron etc.   After my chemo, I not only visit my oncologist every 2 months for labs but also the bypass clinic.   Most people and doctors are totally unaware of
the important part Vitamin D plays in the immune system.   I am curious whether you attend a bariatric clinic regularly and whether they keep your Vitamin D level between 40 and 60.
I'm a nurse and through much investigation was able to provide my oncologists and the gastric bypass surgeons with proof of the cause of my Lymphoma. 
My severe Vitamin D deficiency caused a plunge in my WBC, down to 3.  None of the doctors had any idea.  Three years later I was diagnosed with Lymphoma.  My WBC has increased with
the increase of my Vitamin D not even mentioning the impact on how great I feel.  I am presently working with my oncologist to begin treating Lymphoma pts. with Vit. D during their treatment.
A research study from Mayo Clinic reports Vit. D. administered during Chemo for Lymphoma pts. will double their life expectancy.   Please research Vit. D def.   It has proven to cause, lupus,
colon cancer, lymphoma, fibromyalgia, graves disease, and MS.  MS is one of the few diseases that we see their doctors treat them with huge amounts of Vit. D.  They like their levels at a toxic rate to help subdue symptoms of MS.    Don't get me wrong their are also other reasons for
cancer but my cancer was caused by a low Vit. D. deficiency and immune system.  My WBC levels were comparable to a transplant pt. who is also at a very high risk for cancers.
Hope to hear from you soon and that this information may help you in some way..
Diane

 I too was diagnosed with breast cancer 1yr out from my band surgery. I had lost 80 lbs. Was just enjoying life with the weight loss. I have gained 30 lbs since my diagnosis. Because my cancer is hormone positive, I take Amidrex and had a total hysterectomy. I have not been able to lose the weight. No hormones no weight loss. I feel like I'm losing the battle. I tried exercising for two months straight only lost and gained same amount. I am discouraged. I feel like a fat slob, just like before the band. I'm thinking of taking prescription diet pills. I can't take anything that has to do with hormones. This sucks! The only good thing is I am 3 years cancer free & I didn't have to have chemo or radiation. Just did a double mastectomy. Let me know if you have found a way that is working for you. Good luck!