Side effects of cancer drugs
often surface years after
Have you had a medical problem, which you think might have been caused by one of the drugs you are prescribed – but doctors pooh – poohed any suggestion these might be the cause?
Recently Reuters Health reported on a story released by Canadian researchers, saying that “serious and sometimes life-threatening side effects often go unreported until years after cancer drugs have been approved”. Reuters Health compiles serious analysises of medical research and treatment emanating from major studies.
For many patients, drugs are life-extending. We wouldn’t have improved survival statistics if it wasn’t for these products. However, a growing minority are experiencing side effects caused by these drugs – some of which are very nasty.
When asked if they have experienced problems, for many cancer patients the answer will be a resounding yes. Often they have tried to get their medical team to listen if they report problems, but find it impossible to get them to even check if symptoms might – just might – be caused by a drug they were or are on.
If you have experienced problems, researchers from the University of Toronto have discovered, “within four years of approval, five of the 12 drugs they looked at had earned a “black box warning” from the U.S. Food and Drug Administration, which approves new medications”.
The research was led by Prof. Ian F. Tannock, who says “it’s a warning to be very careful.,” Tannock is an oncologist at the University of Toronto, and said “patients need to be informed that with a new agent there may be added risks.”
Tannock’s team examined so-called targeted therapies, a budding class of cancer drugs that work by interfering with specific molecules involved in tumor growth. Therefore it was expected that the medicines would be safer than traditional chemotherapy.
However, results questioned this assumption. When questioned by Reuters Health, Dr. Thomas J. George commented, “it’s concerning to say the least. When we as oncologists prescribe new therapies we have to be on the constant lookout for side effects and outcomes that aren’t necessarily what the trials would have predicted,” added George, of the University of Florida. (George was not involved in the study).
The new findings come in the wake of research showing that most trials of experimental cancer drugs report increases in at least one severe or life-threatening side effect.
So what about your experiences?
You might have had nasty problems, and wondered if these were caused by the drugs you were put on. But when you ask your oncologist, they tell you, “I have never seen/heard of this before”.
But they need to be more vigilant, and keep up with what the researchers come up with.
After all, who would have connected carpal tunnel syndrome with a commonly-prescribed aromatase inhibitor? Or heart problems, skin lesions, blindness, etc? All symptoms that have recently been acknowledged as possibly been caused by drugs patients were taking.
Some of these horrid conditions may have had nothing to do with the drugs they were taking, but the medical profession needs to undertake more research and LISTEN to patients, before they dismiss their fears. Most patients won’t challenge a doctor, but sadly they often need to do so.
Why does this happen?
According to the Reuters report, one reason why this can happen is that trials, which form the basis for FDA drug approval, might be too small for rare side effects to surface, or they include only highly select patients.
To help yourself, you can now point to this research, and other studies, and demand more investigation.
What happens in UK
In Britain, cancer survivors have long suspected that drugs they are on might cause problems, but with the limited average of ten minutes allocated for an NHS visit to an oncologist in Clinic, many don’t have time to discuss what might be causing these. The solution is often the easy option of “come off the drugs”.
This is not fair on the patient, who wants the reassurance that the drugs might help them to live longer. But may well be a contributory factor to why, in Britain, our survival rates lag behind those of most European countries. From personal experience, when I had nasty side effects, and had been told to “come off the drugs”, I didn’t. Instead I went off to hospitals in France and Germany, where the side effects I experienced were well documented, and immediately the doctors to whom I spoke suggested clinically trialled solutions – which worked.
But this took time : the doctors had to listen to me, examine me, take samples, swabs, go through my medical notes, ask questions, etc. in order to come up with a solution which worked. This type of treatment is something that the NHS has less and less time to offer to patients.
Or the drug companies tell the patient to “fill in the Yellow Card”. These are a fairly long form that the patient fills in, listing symptoms. Patients will often have to phone round to get facts confirmed. Once filled in, they are sent off – and that’s the last the patient hears. When I phoned to ask what had happened to ‘my Yellow Card, I was told “because of Data Protection Act we can’t tell you – even though you filled in the card. So I gave up.
Solution would be to be more helpful to patients, and take a pro-active stance in investigating – but drug companies hide behind convenient rules and regulations, which mean that patients have the frustration of trying to find information, but coming up against brick walls. Then they are told to go back to their doctor – the very person who has originally dismissed their concerns and told them “I have never seen this before”, or similar statements.
Or else the solution means going to a major cancer centre in Europe get solutions. But who can afford this every time?
Why does this happen?
Tannock says the problem is that very few doctors actually look at the labels. Instead, they stick with the published studies that led to the drug’s approval and first label.
Focusing only on drugs with updated labels, Tannock’s team found that half of the 76 serious side effects described in them hadn’t been on the initial label. Of potentially fatal side effects — such as blood clots, strokes and lung problems — that number was 58 percent.
“Many of the reports that led to the warnings did not come from published studies,” added Tannock, whose findings appear in the Journal of Clinical Oncology.
So if you have unexplained side effect:
Print out report link.reuters.com/byd27m
1. Take this to your Oncologist and/or CNS
2. And don’t take no for an answer.
Background on Prof. Ian F. Tannock
Currently working for Ontario Cancer Institure, gained his PhD at Inst. Cancer Research UK in London etc.
If you Google him you come up with a lot of very interesting info, particularly his statement, “I have a long-standing interest in improving methods for undertaking clinical trials, and especially in use of endpoints such as quality-of-life that reflect patient benefit directly. We have applied these endpoints in clinical trials for patients with prostate and breast cancer, and are interested in the mechanisms by which chemotherapy may cause fatigue and cognitive dysfunction.