Obesity is a risk factor for many cancers. But even if this were not the case, the increase in the number of people living with obesity means that more obese people will be diagnosed with cancer than ever before.
The many complex issues facing oncologists in managing their obese cancer patients are nicely summarized and reviewed in a paper by Wenjing Tao and Jesper Lagergren from the Karolinska Institute, Stockholm, Sweden, in a paper published in Nature Reviews Clinical Oncology.
As the authors point out, not only does a large body of epidemiological evidence link obesity to increased cancer incidence, but there is also evidence suggesting poorer survival in obese patients with cancer.
There are also a number of important challenges related to diagnosis including reduced participation of obese individuals in cancer screening programs, lower tumour-marker expression and problems with medical imaging among obese individuals.
Excess body weight also alters pharmacokinetics of chemotherapy and hormone therapy and precision of radiotherapy might be adversely affected by greater skin motility and increased motion of internal organs.
Obese patients can also face higher risks of complications with surgery and recovery times may be affected.
Finally, the authors discuss the importance of sarcopenic obesity and the problem of excess weight gain associated with cancer survival, both of which can affect long-term outcomes.
But, as the authors conclude,
“Although the number of obese patients with cancer is rapidly growing, there is a lack of evidence-based clinical guidelines specifically addressing diagnosis and treatment for these patients.”
Tao W, & Lagergren J (2013). Clinical management of obese patients with cancer. Nature reviews. Clinical oncology PMID: 23856746