ESGO 2013

Outcomes of early stage ovarian endometrioid carcinoma

Dr Aalok Kumar - Medical Oncology, British Columbia Cancer Agency, Vancouver, Canada

 

Aalok, it was really interesting hearing your presentation here because you’ve taken this sub-category of ovarian cancer. Tell me all about it and your studies, endometrioid ovarian cancer.

Our study, it’s actually a retrospective study. In British Columbia we actually collect all the data on all of our ovarian cancer patients and we wanted to look at only the endometrioid subtype. There are five main subtypes in ovarian cancer and this is one of them. Last year Dr Paul Hoskins published all the data on the clear cell so we wanted to continue this and now look at the endometrioid.

And it’s a big study, a big period of time – 1984 until 2008.

Yes, it is a large time and I think part of that is due to the fact that we don’t have a lot of cases of this subtype and we needed to have a large, therefore, time period to have enough patients to analyse.

But you got 172 patients and what happened?

What we basically found was that overall these patients do well. There may not actually be need for any adjuvant treatment in a lot of these patients, however, there is subgroup of patients who have a more poor prognosis, specifically those who have stage 1c disease based on cytology and surface positivity and older than 55, as well as stage 2 patients. They have a poor prognosis and potentially might benefit from radiation although the numbers are quite small.

So reassuringly you confirmed a 95% disease free survival of five years for the majority low risk patients. But then there was this question about age. What actually happened with age? How older was higher risk?

Patients who are older than the age of 55 we found on our multi-variant analysis actually conferred a higher risk in terms of the disease returning. So it’s an interesting feature, something to keep in mind.

And what exactly did you find about adjuvant treatment, should that be used throughout for the high risk population? Did you find that as a recommendation?

What we found was that there is no significant difference with chemotherapy as well as radiation. But the numbers are small because there are only 32 patients in these poor prognostic groups.

So in the poor prognostic group neither chemotherapy nor radiation has proven efficacy?

Significantly. There looks to be a possible trend but the numbers are too small and we need more cases to do a proper analysis.

And what has been done conventionally in the past with these patients?

Conventionally what has been done is that they get chemotherapy. In our centre we give three cycles of chemotherapy with radiation, actually, that’s our conventional base treatment based on our own institution’s experience. Internationally these patients are approached with just standard six cycles of chemotherapy because there’s not a huge belief in radiation around the world, to be honest.

But, from what you’re saying, the chemotherapy might not be doing them very much good?

Exactly. I think the majority benefit in this population is actually coming from the radiation, to be honest.

So what would be your recommendation? Presumably you could reduce treatment levels?

Yes, my recommendation would be to use a re-stratification approach. I don’t think we should be using one fix for all patients, rather patients who maybe fit these poor prognostic features like we’ve identified or any molecular features that are inner works, if they’re identified in this subgroup as having a poor prognosis offering them adjuvant therapy in the form of radiation, chemotherapy maybe but I think it’s more mostly radiation.

So you’ve got more weight of evidence for radiation at the moment than for chemotherapy?

Yes. Even actually last year data from our centre in the clear cell type, which is actually related to the endometrioid type, actually showed a benefit of radiation that was significant. It was published in the JCO so extending from that there’s likely going to be benefit with radiation in this subtype as well, just the numbers are too small.

So how much do these new data help doctors to clarify the importance of looking at the subtype of ovarian cancer?

This data just reaffirms that a number of years ago we were treating ovarian cancer, all types we treat the same. I think this data just is another piece of information that adds to the whole package that we should be looking at the specific types of ovarian cancer. High grade serous treat differently than clear cell, than endometrioid, than mucinous, than low grade serous. They’re all different and this is what our data shows.

So do you feel now equipped to individualise therapy better?

I think this helps us although I think there’s still a lot of work to be done because I cannot go out and say that we should definitely be giving radiation, I don’t have the definitive data behind that. Nor do I have definitive data regarding chemotherapy. We still have to work through that but I do feel that I can tell you, from a prognostic point of view, individually based on your subtype how you will do.

And you’re lacking a few weapons in your armoury, aren’t you?

Yes, exactly.

What about targeted therapies? Is there any chance of using them in the future?

Yes, I definitely think so. There’s actually a number of trials going on in these non-serous histology subtypes looking at targeted therapies. In the clear cell type there’s a number of targeted therapies being explored. I think endometrioid would also be a good group to explore targeted therapies given that some of the mutations that we do see in this group of patients but that work is still only being done in the advanced setting, it’s still going to be some time before it makes it into the early stage arena.

So, from here, from your announcement here today in Liverpool, give me a bottom line take home message for doctors.

Sure. I think the bottom line is that overall early stage ovarian endometrioid cancer patients do well. In those patients who have high risk features like stage 2 or stage 1c and older than the age of 55 think about giving radiation.

Thank you very much.

No problem.