How well people come through cancer treatment might be determined by their genes.

The results of a new study provide preliminary evidence of a “potentially strong and specific” relationship between the genetic makeup of cancer patients and their quality of life during treatment.

Dr. Jeff A. Sloan from the Mayo Clinic in Rochester, Minnesota reported the findings this week during the meeting of the American Society of Clinical Oncology.

“If individual patients with a genetic predisposition for deficits in quality of life can be identified, interventions can be applied to improve the quality of life of these patients,” Sloan said. “These could include interventions to prevent the onset of a deficit or to adopt a watchful waiting approach.”

Genetic variants have been linked to the toxic effects of cancer therapy and to clinical outcomes, but few studies have explored the relationship between genes and quality of life.

Sloan and a multicenter team investigated this relationship in 494 patients undergoing chemotherapy for metastatic colorectal cancer. The researchers were particularly interested in three genes involved in cellular health - DPYD, MTHFR, and TYMS.

They found that patients with a variant version of DPYD were significantly less likely to report fatigue than patients with the usual form of the gene.

In addition, patients with a specific marker near the TYMS gene were more likely to report distress and fatigue, yet to have a positive outlook, than were those without this marker.

MTHFR gene variants did not correlate with quality of life.

“The ultimate goal is to use information about a cancer patient’s individual genetic makeup to tailor individualized treatments to improve quality of life in the same way that has been envisioned for treating the tumor itself,” Sloan said.