- Demographic and lifestyle characteristics, including cigarette smoking, are not associated with receipt of radiotherapy by patients with ductal carcinoma in situ (DCIS), according to the NIH-AARP Diet and Health Study.
Why this matters
- The findings suggest that demographic/lifestyle factors, such as smoking, did not confound the earlier blockbuster finding that radiotherapy receipt by DCIS patients increased the risk of second nonbreast cancers, including lung cancer, according to an analysis of the Surveillance Epidemiology and End Results (SEER) database.
- Prospective cohort (n=1628) of incident DCIS (1995-2011) patients in the NIH-AARP Diet and Health Study.
- Clinical information and radiotherapy were obtained from state cancer registries.
- Funding: NIH.
- Radiotherapy was received by 45% of DCIS patients (n=730).
- Most lifestyle/demographic factors were not associated with radiotherapy receipt, including current smoking (OR, 0.97; 95% CI, 0.70-1.34).
- Moderate alcohol consumption and infrequent physical activity were related to radiotherapy receipt but there were no significant trends for each (Ptrend=.18 and .35, respectively).
- Radiotherapy receipt was strongly associated with several clinical factors:
- More recent diagnosis (2005-2011 vs 1995-1999: OR, 1.60; 95% CI, 1.14-2.25).
- Poorly vs well-differentiated tumors (OR, 1.69; 95% CI, 1.16-2.46).
- Receipt of endocrine therapy vs no endocrine therapy (OR, 3.37; 95% CI, 2.56-4.44).
- Low response rate.
- Observational design.