Cervical cancer breakthrough cuts cancer recurrence by 35%
But first, scientists say they have made the biggest breakthrough in the treatment of cervical cancer in 20 years. The study by researchers at University College London cut the risk of women dying from the disease or the cancer returning by around 35%. So, how did they do it? Dr Mary McCormack is the lead investigator of the trial at UCL Cancer Institute.
Mary - The gold standard is weekly chemotherapy, the drug called cisplatin, and daily radiotherapy for five weeks. That's the external component of the radiation, and then internal radiotherapy, also called brachytherapy. So it's those two components and a drug delivered once a week. That is still the gold standard and has been for 25 years.
Chris - And when you do this, hitherto, we've been achieving about a 70% success rate.
Mary - Well from trials that have been published in the last couple of years, we could expect that 7 in 10 women would be alive at five years.
Chris - And where did you think there was a gap in terms of the treatment regime, then? Where did you try and intervene differently?
Mary - The main problem we felt was that the cancer was coming back outside of the area that was treated with the radiotherapy. So we could treat the area where the cancer was, treat the draining lymph glands, but the cancer would come back, for example, in lymph glands in the belly area or it might come back in the lungs. It would come back somewhere else. That was really the problem that we wanted to tackle.
Chris - And how did you try and do it differently then?
Mary - We put a new twist on an old theme. Some years ago, people had tried to give chemotherapy before the radiation, but some of the trials weren't very well controlled, they were quite small, and there were lots of different regimens. So we said, let's take the most active drugs that we have in this type of cancer - which is carboplatin and paclitaxel - let's put those two drugs together. We know they work well, let's give them every week because that then doesn't allow the cancer cells time to recover. Let's do it for six weeks because if we do it for many, many weeks longer than that, then we may compromise the rest of the treatment. The other thing we did was we said, as soon as we've done these six weeks, we must get on with the radiotherapy immediately afterwards. We must start that in week seven because, if we leave a gap, the chances are the cancer will start to regrow again and we might potentially be worse off than we were before we did anything at all.
Chris - And how did you do the trial to compare what was the best approach?
Mary - So we recruited 500 women and randomised them. 250 women to each group, 250 to the standard treatment and 250 to the standard treatment with the additional chemotherapy for six weeks beforehand. And we worked it out in such a way that we made sure we had two groups of women that were well matched, similar ages, similar extent of the cancer, similar size cancers. We treated them, we followed them up to year five, and at each time we checked to see was there any evidence that the cancer had come back, and also how they were in general terms. Did they have any more side effects? And how were they getting on generally?
Chris - And how did the two groups compare?
Mary - So in our standard of care arm, which is our standard chemoradiation, 64% of the women were alive without evidence of cancer at five years. However, in the group where we gave the additional chemotherapy, 73% were alive without evidence of the cancer coming back. So almost 1 in 10 more women were alive at five years with the additional chemotherapy. We also then looked to see how many women were alive overall and, again, we found that in the standard arm, 72% were alive at five years. However, in the arm where we gave the additional chemotherapy, we found that 80% were alive at five years. So this is our absolute improvement of 8%.
Chris - Do you have an insight into why this is making such a difference, how it's working?
Mary - I think because we are giving weekly treatment early in the treatment of the whole disease. Also, I think we're treating those cancer cells that might have escaped and that might be lurking or nesting somewhere else, but haven't had a chance to grow. Those are the ones that we don't pick up on any scans, and if we get rid of those early, they're not going to be able to grow into secondary tumours. This is what we were able to demonstrate: that we had less recurrences in those areas like the lungs when we gave the additional chemotherapy. And I think this is probably what's accounted for the improvement in the survival rate.
Chris - It is a big reduction in mortality potentially, isn't it? Is this going to become the standard of care now, then?
Mary - I certainly hope so. Many of the centres that treat cervical cancer participated in the trial and the drugs are cheap. So this should help it to come into use widely in other parts of the world as well, particularly where this problem is even bigger; South America, Southeast Asia, places in Africa where the numbers are vast. And if they can ensure 1 in 10 extra women are alive at five years, that would make a huge difference, there.