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Azathioprine and Squamous Cell Skin Cancer

I apologize if some of you have already read part of my story on other threads but I wanted to specifically target this question to those on Aza.

I have been in remission on Aza for 14 years now. It has been a life saver. Almost like not having Crohn's colitis at all after years of suffering. Of course, cancer has always been in the back of my mind from the Aza and I have been concerned about staying on it but I followed my doctors advice and stayed on it. He is one of the top doctors in the Chicago area. I was on 75 mg.

I recently had Squamous cell skin cancer and actinic keratosis along with some other pre-malignant skin lesions removed and now my GI doctor and I discussed it and thought it best to stop the Aza. Just stopped it this past Monday after a colonoscopy. Talk about being careful what you wish for. I kind of always wanted off of it and now I am. But now the unknown faces me. He said if I were to flare, it probably would not be right away.

Has anyone else developed skin cancers while on Aza? How long were you on it and did you stop the Aza? Did you stay in remission after stopping the Aza? I'm hoping my body has just finally burned itself out on the Crohn's colitis and really the Aza wasn't doing anything after 14 years.

Thanks for any advice/thoughts.
I would've stayed on the aza, since it was working. SCC isn't very dangerous and can be cut out. I've had multiple BCC and a couple melanoma-in-situ. As well as atypical moles. I've only been on aza for about 5 months. In that time, I had an atypical mole that had to be cut out.
Going for a biopsy on Wed for possible skin cancer on nose. Somewhat frightened by this side-effect of Azathioprine. Anyone out there have stories, advice, etc?
I haven't have skin cancer since taking Azathioprine, but I did have a Melanoma 4 years ago. And I also go to UV light therapy for Psoriasis; so it does weigh heavily on my mind weather Im am putting myself at risk for another skin cancer..Double edged sword.:mad:
Follow Up To Stopping Aza

Well, all was fine in the beginning but now about six weeks to the day of stopping the Aza (after about 14 years in remission), I am having some mild problems. Fortunately, so far, they are only mild but abit painful. An old fistula may be rearing it's ugly head. Not a fun jolting of my memory after this amount of time.

Called his nurse hoping he'd just put me back on the Imuran but she said he wants to see me so I'm going back next week. Honestly, I think I just may tell him (or beg him - haha) that I want back on the Imuran and take my chances. After over 30 thirty years with this disease, it has always needed medication to keep it at bay. Dr. had briefly mentioned trying Methotrexate but I wasn't fond of those side effects either.

Wondering what he's going to tell me. Recently saw my dermatologist for a skin check and she said she didn't necessarily think the skin issues I've had thus far warranted stopping the Imuran esp. at my dosage but I may have whined too much to my GI doc about the Squamous. Ugh. We shall see.


Senior Member
I was on AZA.. Went toxic on it. ER docs took me off it immediately.. 4 years later, skin cancer starts to develop. Nipped in the bud in pre-cancerous state. Continuing to watch for it as well as colo-rectal cancer... (I'm on 12 month follow up with the skin cancer, and 6 month follow up on the colo rectal stuff.) I had thought that finding LDN and switching to it kept me out of the woods on all of those side effects from traditional crohns meds, but not so fast. Anyway, LDN has taken care of my Crohns, and my combined medicos are working to see that neither skin nor colo rectal cancer ruin my new found health. If you've had a close call/near miss with cancer, you may want to take a look at LDN. If it works for you, you're laughing; if it doesn't..no harm done. You simply have to resort to the traditional meds and take your chances with the side effects
I was on azathioprine for years and I stopped taking it on my own about 18 months ago. It wasn't doing anything for my Crohn's. In fact I got better after stopping it. I also figured out it was causing my knees to ache and was a severe drain on my energy.

Also, there's some studies which show it's not a useful for Crohn's/Colitis.
I've been on aza for 5 years, I'm 24. I knew about this possibility and the possibility of other (worse) cancers, but lately it's been stressing me out and I'm going to go talk to my doc about it tomorrow.

It just worries me that it increases the risk of it. By the time I'm 49, I will have been on it for 30 years, it just doesn't seem like the odds are in my favor in the long run...

Any thoughts, advice, anecdotes?
I was going to start my own thread, but this seems to cover a lot of what I was going to ask.
I've been on AZA for about five years now. The effects have been very beneficial... so beneficial that my consultant broached the subject of coming off the drug when I saw him in April this year. But it was all a bit sudden and unexpected, so I decided to stay on until I see him again next April. My consultant seemed to think that this would be a good idea.
Since then, I have been diagnosed with a basal cell carcinoma on my face... I'm going to have this removed in three weeks time, but it has given me something else to think about.
I will be making a decision about staying on AZA before next April... but, as above, I'd be grateful for any "thoughts, advice, anecdotes"
Hello to all. Have been on imuran and pentasa for 10 years or so. Small bowel resection 8 years ago followed by near remission. Began to develop basal and squamous cancers on face, neck and scalp 6 or so years ago and now having 2 to 3 surgically removed per year via Mohs surgery which limits the scarring.

Chose to go off Imuran a year or so ago since CD was minimal. Doctor said it would take 3 or so months to see if that was a good choice or not. 4 months later I developed stricture and was hospitalized and now back on Imuran, but we are considering shifting to Humira or Cimzia.

Skin cancer relationship to Imuran seems well established in literature. But I am also fair skinned and grew up in the south before sunscreen so there is likely unrelated skin damage involved. But I do believe the Imuran may have escalated the growth of those skin cancers.

I would like to know if folks using the TNFs like Humira or Cimzia are also experiencing increased skin cancers. Though not life threatening, at 59 I am getting close to having a year around Frankenstein look due to the surgeries!

So, in my experience, yes Imuran has escalated the skin cancers and yes the stopping of the Imuran was unsuccessful.

Mike, I dunno if this will help much but you can look at rxisk.org. They are trying to collect drug side effect information. I know they've collected some information about the biologics but I haven't see the full reports.

(It also occurs to me that you might want to contribute to rxisk.org concerning your experience with azathioprine.)
Ahh this is terrifying - I have just started on Aza (last week) and getting really worried about this side effect - I have quite fair skin (lots of freckles & moles) & where I'm careful in the sun now - I have been burnt quite badly a couple of times in the past.

Is this a very common risk of being on Aza?

At 29, the possibility of having cancereous lumps/moles cut away from the face especially (as vain as that might sound) is very worrying! Eeeeeek!

Does anyone have any tips on how to properly check your skin or what exactlty you should be looking for (except from the obvious abnormal moles)?
Ahh this is terrifying - I have just started on Aza (last week) and getting really worried about this side effect - I have quite fair skin (lots of freckles & moles) & where I'm careful in the sun now - I have been burnt quite badly a couple of times in the past.

Is this a very common risk of being on Aza?

At 29, the possibility of having cancereous lumps/moles cut away from the face especially (as vain as that might sound) is very worrying! Eeeeeek!

Does anyone have any tips on how to properly check your skin or what exactlty you should be looking for (except from the obvious abnormal moles)?
Similar to my complexion and history. I would say that if you're careful and cover up and use high factor sun block, you'll probably be at less risk than someone not on aza who isn't careful. I still tend to think that my problems arose from my behaviour in the 1970s when I used to fry for hours on end.

You may have to go through the slight inconvenience of getting referred to a dermatologist via your GP. To save time and effort.. try and keep a list of everything you're bothered about. I had all kinds of lumps and bumps and the dermatologist looked at every one... some were the remnants of insect bites from many years ago, for example.

You should also look out for any changes in existing moles... size, colour, itchiness. You can get moles removed very easily. I had two prominent moles taken off my face only a few months ago... they weren't causing any problem but I had it done as a precaution. Very quick and easy and now there is no sign they were ever there. They were biopsied and results were ok. I had it done on the NHS for health reasons (also kept cutting them when shaving)... but I must say that I'm rather pleased with the results... cosmetically speaking!
That puts my mind at rest a wee bit - would GP's generally refer you to a Dermatologist on NHS for check ups if there wasnt anything obviously wrong at the moment?

I guess being on Aza and therefore being very cautious in the sun and checking ourselves more often, we're probably in a better position than the average person in the end. I've been on Kids SPF 50+ these past few days - this kind of sunshine is rare in Scotland so I'll try not to worry too much.
You'd need to have some sort of lump or spot to show the dermatologist. Best just to keep checking yourself. Then, if you have any concerns, go to the GP, let them look at the spot and say you're rather concerned because you're on aza etc etc.
Personally, I still think the risks are very low and the benefits of being on aza (for me) outweigh the risks. I go on foreign holidays about three times a year... as it happens I'm quite happy covering up and sitting in the shade... so no problem
omg I just read this on the FDA website:

"Azathioprine (also known as Imuran) and mercaptopurine (known as Purinethol) also suppress the immune system. They are commonly used as part of a combination regimen or used alone to treat Crohn’s disease and ulcerative colitis, although they are not approved for those uses."

I had no idea!
mike98926, I just came across this document on the FDA website:

There's a small "Risk of Cancer" section. Here's the relevant quote for your question.

Risk of Cancer
 There have been cases of unusual cancers in children and teenage patients
using TNF-blocking agents.
 For children and adults taking TNF-blocker medicines, including REMICADE,
the chances of getting lymphoma or other cancers may increase.
 Some patients with Crohn’s disease or ulcerative colitis have developed
Hepatosplenic T-cell Lymphoma, a rare type of cancer. Most of the patients
were teenage or young adult males. This type of cancer results in death. All
of these patients had received medicines known as azathioprine or 6
mercaptopurine together with REMICADE.
 People who have been treated for rheumatoid arthritis, Crohn's disease,
ulcerative colitis, ankylosing spondylitis, psoriatic arthritis and plaque
psoriasis for a long time may be more likely to develop lymphoma. This is
especially true for people with very active disease.
 Some people treated with REMICADE have developed certain kinds of skin
cancer. If any changes in the appearance of your skin or growths on your
skin occur during or after your treatment with REMICADE, tell your doctor.
 Patients with COPD (a specific type of lung disease) may have an increased
risk for getting cancer while being treated with REMICADE.
 Tell your doctor if you have ever had any type of cancer. Discuss with your
doctor any need to adjust medicines you may be taking.
Hi, I was previously on Azathioprine for over 15 years but had to be taken off of it a couple of years ago due to a finding of a squamous cell carcinoma on my back. I am still under the care of dermatology due to constant findings of skin lesions which have ranged from solar keratosis and bowens disease with some basal cell carcinomas thrown in! altogether I must have had cryotherapy on over 100 lesions! Unfortunately I have had several flares since coming off of it, and have twice been on Humira - currently on it now but it doesn't seem to be working! Also on Budesonide for the Crohns but still having problems.

Previously had one bowel resection, gallbladder removal, pilonidal sinus surgery, perianal abscess surgery and botox for anal fissure.
Having awful skin issues on long term 6mp for 18 years.. warts, lesions, brown spots everywhere and spreading like wild fire! Very worried about skin cancer...going to new GI Doctor this week.
I'm just starting AZA now and wondered myself what the odds are of developing skin cancer. I asked my doctor if he could send me some literature and the main points I feel are worth sharing here are:

1. Regarding stopping AZA ou 6MP and flaring:

"Patients who discontinue treatment with AZA or 6-MP have a high rate of relapse. In one prospective cohort study, 87 percent of complete responders relapsed after discontinuing treatment with 6-MP [18]. Once a desired therapeutic effect has been achieved, studies have suggested that therapy be continued for anywhere between 12 months to 5 years to reduce the likelihood of relapse [19-22]. However, another study found that duration of treatment did not influence the likelihood of relapse following treatment withdrawal [23].

Whether a slow dose reduction every 6 to 12 months (rather than abrupt discontinuation) reduces the risk of relapse has not been evaluated in controlled clinical trials. As continuation of AZA and 6-MP is associated with maintenance of remission and there is a high risk of relapse when therapy is discontinued, in the absence of side effects, our approach is to continue AZA and 6-MP long-term in patients whose disease is well controlled [19-22,24].

There is no evidence to support a dose reduction in patients in remission in order to prevent long-term side effects. Furthermore, a dose reduction may put the patient at risk for relapse. Thus, once therapy is tolerated and remission is maintained, there does not appear to be a compelling reason to reduce the dose.

2. Regarding the risk of skin cancer:

Patients with IBD are at an increased risk for melanoma [30]. In a meta-analysis of 12 cohort studies, patients with IBD were at an increased risk of melanoma as compared with the general population (relative risk [RR] 1.37, 95% CI 1.10-1.70), with a pooled crude incidence rate of melanoma of 27.5 cases/100,000 person-years (95% CI 19.9-37.0) [31]. The risk was increased among patients with Crohn disease and ulcerative colitis (RR 1.80; 95% CI 1.17-2.75 and 1.23; 95% CI 1.01-1.50, respectively). This risk appeared to be independent of biologic use, which may also increase the risk of melanoma [32].

Among patients with IBD, the use of thiopurines has been associated with nonmelanoma skin cancer (NMSC) [33]. In a meta-analysis of eight studies that included 60,351 patients with IBD, the risk of NMSC was increased twofold with the use of thiopurines (hazard ratio 2.28, 95% CI 1.5-3.5) [34]. However, there was significant heterogeneity between studies included in the meta-analysis, and the risk of NMSC may be overestimated due to ascertainment bias.

I think the take home message here is that taking AZA or 6MP and having an increased risk of cancer is still better than having uncontrolled Crohns. Stopping AZA will likely result in a flare. If you must discontinue AZA, you should not be left without any medication. Your doctor should decide on what maintenance meds to put you on.

I also read that AZA and 6mp are good maintenance meds but usually are not enough to send you into remission. That is usually done with steroids or a biologic.

The good news is that we have many more options now than 15 years ago :)

I hope you find another medication that works well for you. My doctor tells me many people stay on biologics as monotherapy successfully!
I have been on azathioprine for about 8 years now. First of this year I was told that I should have a complete body check with a Dermatologist once a year as our risk of skin cancer is higher. So glad that I did as I did have a spot that was questionable and had a biopsy done. It was pre-cancerous. I would ask your doctors about getting this done sooner rather than later. So glad that I did.
I'm on Aza since 12 years...It's for me too a game changer...No skin problem.
By the way Aza is losting effectivness so i have to change my drug...Probably to Anti Tnf Alpha or to GED 03 01 ( i have possibility to be involved in the trial).

Sad because AZA was great.
I have been on Azathioprine for 18 years that has controlled my ulcerative colitis. I has definitely impacted my skin. I got a squamous cell skin cancer 8 years ago and then another 7 months ago. I went off it immediately but still not a 3rd squamous after being off it for 6 months (was told it could take 6-12 months for your immune system to correct itself and the damage may already have been done to my skin. It was a great drug for my UC, but be real careful in the sun. I would not have done this if I knew the long term impact to my skin.
I don't remember how long i have been on azathioprine but right before Thanksgiving i had a squamous cell cancer removed from my scalp.
Been on Imuran 150 mg a day since early 2009, got one squamous cancer on temple three years ago that needed MOHS, then one on my back the next year, had another one late last year requiring MOHS and lots of little ones that were completely removed just with the biopsy. Then right before Christmas one jumped up on my sternum like a pink, itchy blister, different from the others, very aggressive and fast. I was out of state so waited three weeks to get it biopsied and had it removed today. Ouchie! My gastroenterologist is considering back down my dosage.

My cancers have looked like rough, scaly places or flat, wartlike growths or like a little one-cell black stack. The pink blister was bigger, faster and different. I suggest anyone on Imuran go to a dermatologist for a baseline "mole patrol." And then keep their eyes out for any changes. I see my dermatology nurse practitioner about every three months. I'm seventy three, brown eyed but very fair skinned, grew up in southern US, moved to CA in my twenties and am a sailor but I've been religious about hats and sunscreen since I was twenty five so blame Imuran for most of my skin problems.

I had three feet of my ileum removed in late 2008 because of strictures and have been on the Imuran and Remicade infusions every two months since. Just had an MRI which shows I have no fissures, strictures or inflammation and yesterday's colonoscopy was good, too, so while I may cut back my Imuran dosage I'm not ready to give it up. I just deal aggressively with my spots.

I was diagnosed eleven years ago- or diagnosed myself which wasn't hard to do since my mother died of Crohns when she was 46 and I was all too familiar with symptoms. I'm just grateful they waited so long to hit me.

Here's what I think is a helpful hint : since I no longer have an ileum and since that is the part of the small intestine that processes vitamin B 12, my Dr. prescribed B12 shots which I give myself once a month. There is a test for one's B12 level and mine was normal even before I started the shots but Dr thought it was easier to keep level up proactively. Nobody I know with Crohns has had his Dr inform them of this. Any of you been told about B12?
For myself I feel well B12 shots can't hurt so I'll continue them even if my level is normal just because I'm used to doing it. I also give them to my 76 year old husband and they seem to help with his memory. And I notice you're over 50. Pernicious anemia is one of the causes of dementia.

Maybe you still have your ileum? And are still absorbing that vitamin from your diet. Hope so, anyway. Best wishes for you!
Interesting read here. I too have had skin cancer recently diagnosed by biopsy and am getting a whole chunk pulled on Monday. Not sure about other spots. Like a previous poster I have had some issues with warts as well. Have been working through my GP for this, and will soon get my trough level for remicade checked. Maybe it is time for a complete review of my meds.
I've been on Imuran for about 7 years and am about to have my third SCC removed. On the lip, very nasty. I'll be talking to my Gastro soon to see if I have to discontinue the drug. It has kept me in remission the whole time.