Lung Cancer, a Disease Differently, Depending on Age and Sex

The biology of lung cancer differs from a patient to another depending on age and sex, according to a study signed by researchers at Duke University (USA). The discovery, which is published in “JAMA”, could help explain why certain groups of patients evolve better than others even when seem to have the same disease.

“Our study supports two key discoveries. First, the biology of lung cancer in women is very different from the observed in men. Women, in general, have a disease less complex, at least in term of the numbers of molecular mechanisms involved. Also discovered that there is a subgroup of patients over which could benefit from treatments which are usually reserved for younger patients,” explains Anil Potti, coauthor of the study.

The researchers found that certain molecular mechanisms were most frequently turned in some groups in others and that certain patterns are associated with a better long-term survival in patients with lung cancer.

The rate of overall survival to five years for lung cancer is only 15 percent and remains the main cause of cancer mortality in the United States. Almost half of the new cases are diagnosed in women and approximately between 30 and 40 percent of the diagnoses corresponds to over 70 years. The majority are tumors of small cells.

The authors, led by William Mostertz, discussed relevant differences clinically in biology that underlies this type of cancer by age and sex of patients. The study was based on an analysis of July 2008 to June 2009 of 787 patients with initial phase of the disease that were divided into subgroups according to the age (more or less than 70 years) or sex.

The groups of patients with low and high-risk were related to the survival free of recurrence more or less than five years, within the threads of age and sex. The researchers found that these subgroups demonstrated unique patterns of activation of mechanisms. In patients with less than 70 years, most at risk, with the child survival free of recurrence, showed an increase of the activation of the mechanisms of the gene Src and the tumor necrosis factor in comparison with patients of low-risk. In addition, the high-risk patients aged 70 or more showed a greater activation of the mechanisms of healing of wounds and of invasiveness compared with patients of low-risk.

The authors discovered a difference in the biology of lung cancer among men and women. In the women, the patients most at risk showed greater activation of the mechanisms of the invasiveness and the gene STAT3 while men under greater risk showed an activity increased STAT3, the factor of the tumor necrosis, factor receptor epidermal growth (CSFR) and the healing of wounds.

They believe their findings represent a new method to define groups of stratification in lung cancer non-small cell by age and sex. The system is enriched by mechanisms of activity specific and could be more suitable for therapeutic intervention to take into account clinical trials with drugs that are directed to abnormalities associated with specific mechanisms or the tumor biology.