Are people more likely to gain weight or to lose weight during chemotherapy and/or radiation? As a general trend?
IANAD, but I would be very surprised if people gain weight during chemotherapy or radiation. Both of these work on the principle that if you do something really bad to your body, the cancer cells die before the healthy cells. Both treatments make you very sick. Some of the newer radiation treatments will focus the radiation on the tumor, which reduces the effects on other parts of the body, but that can’t be used for all types of cancer.
One of our medical dopers will be by shortly to give more details.
I would think that too, but recently read a message board post (on another board) by a cancer survivor who said that people usually gain weight during radiation. That’s why I’m hoping to get an answer from someone who knows.
The drugs they give you before chemo include steroids, which can cause you to gain weight. The days of spending the rest of the day vomiting into a toilet are over…there are anti-nausea drugs. I had a bit of queasiness during my chemo, that’s all. I was able to work, go to the gym, do most things (although the Neulasta shot kicked my ass and there were days I had troubles walking.)
However, because I found SparkPeople and kept up with my exercise and nutrition plan, I did lose weight during my cancer treatments. My chemo oncologist told me I was his Energizer Bunny and that I was the only patient he’d had who lost weight during chemo. I won’t say chemo is a bed of roses, but I can imagine there are some folks who just don’t have the energy to exercise.
I hadn’t heard that people gain weight during radiation. The treatment itself is very quick, just a quick zap basically, and you have to be more concerned with the skin damage than gaining weight.
Yep, you’re the person who sparked this question, over on SparkPeople 
So the steroids cause weight gain, and nausea and exhaustion don’t cause the weight loss one would expect. It’s the “you’re the only patient who lost weight during chemo” comment that is so interesting–and that I had interpreted as meaning “people usually gain weight”.
That’s funny - a friend of mine went through chemo during college and joked that he must’ve been the only person in the world who gained weight during chemotherapy. Maybe not.
I don’t know if people gain or lose weight during chemotherapy, statistically, but I could see reasons for either. I agree with ivylass that I don’t see a link between radiation and gaining or losing weight - unless perhaps the radiation was in an area that directly affected the patient’s ability to eat.
My uncle lost a dramatic amount of weight during radiation therapy. IIRC (it was a long time ago) they said it is very common for people who are getting irradiated in the head and neck region, but I don’t remember why they said that was the case. He had to drink several cans of Ensure every day to bring his calorie count way up.
ETA: Trying to look it up to remember the “why” I did find this site about treatment induced anorexia and that sounds about right as per my uncle’s experience.
ETA: Also I don’t believe my uncle had much chemo.
By and large, as has been said, both chemotherapy and radiotherapy tend to lead to weight loss not gain.
That being said, however, some chemotherapeutic drugs can cause salt (and water) retention, and that could contribute to weight gain. It’s not just steroids either that promote salt retention. IIRC, the paxil type drugs as well as the so-called “vinca alkaloids” (i.e. vincristine, vinblastine) do it as well. I am sure there are many others that I just can’t recall.
So, part of the surprise about hearing that chemo can lead to weight gain, is due to forgetting that not all weight gains are the same - it could be due to salt and fluid retention and not just accumulation of fat.
It should also be noted that salt retention (and thus weight gain) can sometimes occur as an indirect effect of the chemo, e.g. if the chemo damages the heart (e.g. doxorubicin or Adriamycin), fluid retention can result. Salt retention and weight gain may also complicate the use of drugs like ibuprofen (Motrin, Advil, . . .), diclofenac (Voltaren, Arthrotec), celecoxib (Celebrex), etc., which are sometimes used to treat the aches and pains of both the cancer and the chemo.
BTW, here’s a site that may be of some interest although it doesn’t really contain a lot of information.
About six years ago I had radiation therapy for prostate cancer. It was “shaped radiation” in that after some X-rays and an MRI, they pinpointed the exact location and size of the tumor. They put three tiny tattoos down south. Then they made a foam cast of my lower body. When the treatments started, I lay in the foam cast so could not move, they had three laser beams up near the ceiling that focused on the tatoo marks after they moved me around. Then I lay still while a huge unit gradually did a 180 degree rotation from one side to the other. That got the beam right on the tumor, and supposedly minimized any destruction of other tissue.
I went five days a week for eight weeks. The first four weeks I felt fine and continued to climb a mountain daily, but the last four I found I was getting really tired, so quit exercise. Of course, I was 76 then, which may have had some effect.
The only other side effect was constipation, but no sickness, dizziness or anything else. I did not gain nor lose any weight.
Still cancer free, knock on wood.
Some people get chemo as follow-up to surgery and the chemo is taking place during a time where the patient is likely to be gaining weight.
Chemo can come when you are relatively healthy (weight can be maintained or increase), desperately at the worst stages (dying of lymphoma and it’s an all-out chemo blitz), or somewhere in the middle.
In and of itself, it would lead to weight loss.
My mother had chemo and radiation for B-cell lymphoma (she’s doing great now) in the early 1990’s. The radiation to her neck burned her esophagus and throat some, making it harder to eat. Some chemo can also affect the lining of your gut, as it did with her, decreasing absorption of food.
However, being fatigued and miserable interferes with exercise and burning calories.