ECC 2015

Hodgkin lymphoma incidence in young affected by social deprivation, gender

Dr Richard McNally - Newcastle University, Newcastle, UK

Richard, tell me about your centre, your job in it.

I’m a reader in epidemiology in Newcastle University. My primary interest is in the etiology and survival of childhood and young adult cancers. Particularly in Newcastle we’ve got a specialist registry containing all the cases of childhood malignancies in the northern England area back to ’68.

That’s a great opportunity to study then. Why were you interested in Hodgkin’s lymphoma?

Hodgkin’s lymphoma, a lot has been done about Hodgkin’s but there are still no clear clues as to what the actual etiological reasons for its origins are. So I think there’s more to be done to study Hodgkin’s lymphoma.

And you were looking for correlations, can you tell me what exactly you did in the study?

Yes, we looked at correlations with age, sex and deprivation. By deprivation we used census measures of area-based socioeconomic deprivation and including components of that, including things like unemployment, household overcrowding and housing tenure.

What came out of your study?

The interesting findings were that we found a female excess for the young women aged 20-24 years over males which is interesting because overall there’s a male excess for Hodgkin’s lymphoma. We also found that for looking at, we were particularly interested in subtypes, that for the nodular sclerosing subtype there was a protective effect of deprivation so that in the more deprived areas there was actually decreased incidence. So that’s a very interesting finding.

Now I know that some of the cases of Hodgkin’s lymphoma are still puzzling but you’ve got some firm correlations now. Do you have any clues about the etiological factors?

The interesting thing is that similar findings have been found for childhood leukaemia and the inference from our findings would be that maybe there’s a similar reason to explain this protective effect for deprivation for this particular type of Hodgkin’s lymphoma. We would perhaps hypothesise that infections or infectious agents might confer protection against subsequent development of this subtype.

Is this the theory that a little bit of dirt does you good?

Exactly, it’s the hygiene hypothesis, yes.

So that’s why the overcrowding could be beneficial?

Potentially. We wouldn’t obviously advocate parents making their children exposed to lots of infections because clearly infections themselves may not be potentially beneficial.

Also harmful. But then you importantly looked at young adults and not just children and you found this extremely interesting correlation, preponderance, in women, young women whereas in kids it’s boys who are more preponderant. So what’s the explanation etiologically for that, do you think?

We think that there might be some modulation or influence of sex related hormones which might lead to the increase in young women.

So it seems to be pointing towards things like hormones but also infectious agents or the immunological response to them that could be controlling Hodgkin’s disease. Does that sum it up?

For this particular subtype. Clearly, for the other subtypes there was no clear evidence but for this subtype, yes, that’s what we would conclude.

Well clearly doctors have an important interest in advising their patients about a host of public health measures. What would you distil out of this for doctors?

I think there’s still further work to be done before clear measures can be given in terms of providing advice for patients. However, I think that this is the first step which indicates that both hormonal factors and factors related to infectious agents which need to be studied further.

Do you think there could be therapeutic targets in there at some time?

Potentially, if these findings are firmed up by further molecular studies then potentially, yes.

Thank you very much indeed.

Thank you.