The link between overweight and obesity, and surviving head and neck cancers

Nicholas Timpson’s research is a pilot study assessing direction and causality in the association between BMI and head and neck cancer survival

Topic: Head-Neck cancer
Institution: University of Bristol
Country: United Kingdom
Status: Completed

Researcher: Nicholas Timpson

Background

Head and neck cancers (HNC) are a heterogeneous group of cancers. Mortality and morbidity is high with 45% dying within 5 years of diagnosis. In HNC patients, observational studies show overweight and obese levels of pre-treatment BMI are associated with increased overall survival, cancer specific survival and increased time to recurrence.

Aims

We set out to run a pilot study that would allow us to thoroughly investigate the true association between weight at diagnosis and head and neck cancer survival.
To conduct a large study investigating weight and cancer survival.
To allow a future study which can assess the true association of weight and HNC survival using genetics, by measuring the genetics of more than 2,700 patients and starting to develop the methods which will be used in the later study.

How it was done

In 10,177 head and neck cancer patients, We used a Body Mass Index, a combination of height and weight at cancer diagnosis to designate patients into underweight, normal weight, overweight or obese categories. We then looked at survival across the different categories of patients.

We used DNA, which had been previously removed from the patients’ blood samples to record their genetic information using a technology called genotyping. We also genotyped ~400 individuals without cancer as a control group. Once complete we ran a series of check on the genetic information so that it could be used for future studies

Findings

We found that underweight patients had poorer survival and were 69% more likely to die compared to normal weight patients.Overweight and obese patients had better survival compared to normal weight patients.

Impact

We were able to successfully record the genetic information of 3117 individuals (2719 head and neck cancer patients and 398 non cancer controls). We recorded just over half a million genetic positions and then used a process called imputation which can calculate many millions of the other genetic positions. Funding being secured which allowed the much larger genotyping effort to be completed.